Chemical abundances of fast-rotating massive stars. I. Description of the methods and individual results

NASA Astrophysics Data System (ADS)

Cazorla, Constantin; Morel, Thierry; Nazé, Yaël; Rauw, Gregor; Semaan, Thierry; Daflon, Simone; Oey, M. S.

2017-07-01

Aims: Recent observations have challenged our understanding of rotational mixing in massive stars by revealing a population of fast-rotating objects with apparently normal surface nitrogen abundances. However, several questions have arisen because of a number of issues, which have rendered a reinvestigation necessary; these issues include the presence of numerous upper limits for the nitrogen abundance, unknown multiplicity status, and a mix of stars with different physical properties, such as their mass and evolutionary state, which are known to control the amount of rotational mixing. Methods: We have carefully selected a large sample of bright, fast-rotating early-type stars of our Galaxy (40 objects with spectral types between B0.5 and O4). Their high-quality, high-resolution optical spectra were then analysed with the stellar atmosphere modelling codes DETAIL/SURFACE or CMFGEN, depending on the temperature of the target. Several internal and external checks were performed to validate our methods; notably, we compared our results with literature data for some well-known objects, studied the effect of gravity darkening, or confronted the results provided by the two codes for stars amenable to both analyses. Furthermore, we studied the radial velocities of the stars to assess their binarity. Results: This first part of our study presents our methods and provides the derived stellar parameters, He, CNO abundances, and the multiplicity status of every star of the sample. It is the first time that He and CNO abundances of such a large number of Galactic massive fast rotators are determined in a homogeneous way. Based on observations obtained with the Heidelberg Extended Range Optical Spectrograph (HEROS) at the Telescopio Internacional de Guanajuato (TIGRE) with the SOPHIE échelle spectrograph at the Haute-Provence Observatory (OHP; Institut Pytheas; CNRS, France), and with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph at the Magellan II Clay telescope. Based also on archival data from the Galactic O-Star Spectroscopic Survey (GOSSS), the Anglo-Australian Telescope (AAT) equipped with the University College London Echelle Spectrograph (UCLES), the ESO/La Silla Observatory with the Fiber-fed Extended Range Optical Spectrograph (FEROS; programmes 70.D-0110, 075.D-0061, 076.C-0431, 081.D-2008, 083.D-0589, 086.D-0997, 087.D-0946, 089.D-0189, 089.D-0975, 179.C-0197, and the High Accuracy Radial velocity Planet Searcher (HARPS; programme 60.A-9036), the Pic du Midi Observatory equipped with the NARVAL spectropolarimeter, the San Pedro Mártir (SPM) observatory with the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO), the OHP with the AURELIE and ELODIE échelle spectrographs, the Nordic Optical Telescope (NOT) with the FIbre-fed Echelle Spectrograph (FIES), the Canada-France-Hawaii Telescope (CFHT), with the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) spectrograph, the Leonhard Euler Telescope with the CORALIE spectrograph.Table F.2 is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/A56

VizieR Online Data Catalog: Radial velocity follow-up of the HD 3167 system (Gandolfi+, 2017)

NASA Astrophysics Data System (ADS)

Gandolfi, D.; Barragan, O.; Hatzes, A. P.; Fridlund, M.; Fossati, L.; Donati, P.; Johnson, M. C.; Nowak, G.; Prieto-Arranz, J.; Albrecht, S.; Dai, F.; Deeg, H.; Endl, M.; Grziwa, S.; Hjorth, M.; Korth, J.; Nespral, D.; Saario, J.; Smith, A. M. S.; Antoniciello, G.; Alarcon, J.; Bedell, M.; Blay, P.; Brems, S. S.; Cabrera, J.; Csizmadia, S.; Cusano, F.; Cochran, W. D.; Eigmuller, P.; Erikson, A.; Gonzalez Hernandez, J. I.; Guenther, E. W.; Hirano, T.; Suarez Mascareno, A.; Narita, N.; Palle, E.; Parviainen, H.; Patzold, M.; Persson, C. M.; Rauer, H.; Saviane, I.; Schmidtobreick, L.; van Eylen, V.; Winn, J. N.; Zakhozhay, O. V.

2018-06-01

We used the FIbre-fed Echelle Spectrograph (FIES; Frandsen & Lindberg 1999anot.conf...71F; Telting et al. 2014AN....335...41T) mounted at the 2.56 m Nordic Optical Telescope (NOT) of Roque de los Muchachos Observatory (La Palma, Spain) to acquire 37 high-resolution spectra (R~67000) in 12 different nights between July and September 2016. We also acquired 50 spectra with the HARPS spectrograph (R~115000; Mayor et al. 2003Msngr.114...20M) and 32 spectra with the HARPS-N spectrograph (R~115000; Cosentino et al. 2012SPIE.8446E..1VC). HARPS and HARPS-N are fiber-fed cross-dispersed echelle spectrographs specifically designed to achieve very high-precision long-term RV stabilities (<1 m/s). They are mounted at the ESO-3.6 m telescope of La Silla observatory (Chile) and at the 3.58 m Telescopio Nazionale Galileo (TNG) of Roque de los Muchachos Observatory (La Palma, Spain). (1 data file).

An echelle spectrograph for middle ultraviolet solar spectroscopy from rockets.

PubMed

Tousey, R; Purcell, J D; Garrett, D L

1967-03-01

An echelle grating spectrograph is ideal for use in a rocket when high resolution is required becaus itoccupies a minimum of space. The instrument described covers the range 4000-2000 A with a resolution of 0.03 A. It was designed to fit into the solar biaxial pointing-control section of an Aerobee-150 rocket. The characteristics of the spectrograph are illustrated with laboratory spectra of iron and carbon are sources and with solar spectra obtained during rocket flights in 1961 and 1964. Problems encountered in analyzing the spectra are discussed. The most difficult design problem was the elimination of stray light when used with the sun. Of the several methods investigated, the most effective was a predispersing system in the form of a zero-dispersion double monochromator. This was made compact by folding the beam four times.

PEPSI spectro-polarimeter for the LBT

NASA Astrophysics Data System (ADS)

Strassmeier, Klaus G.; Hofmann, Axel; Woche, Manfred F.; Rice, John B.; Keller, Christoph U.; Piskunov, N. E.; Pallavicini, Roberto

2003-02-01

PEPSI (Postham Echelle Polarimetric and Spectroscopic Instrument) is to use the unique feature of the LBT and its powerful double mirror configuration to provide high and extremely high spectral resolution full-Stokes four-vector spectra in the wavelength range 450-1100nm. For the given aperture of 8.4m in single mirror mode and 11.8m in double mirror mode, and at a spectral resolution of 40,000-300,000 as designed for the fiber-fed Echelle spectrograph, a polarimetric accuracy between 10-4 and 10-2 can be reached for targets with visual magnitudes of up to 17th magnitude. A polarimetric accuracy better than 10-4 can only be reached for either targets brighter than approximately 10th magnitude together wiht a substantial trade-off wiht the spectral resolution or with spectrum deconvolution techniques. At 10-2, however, we will be able to observe the brightest AGNs down to 17th magnitude.

Performance of the CHIRON high-resolution Echelle spectrograph

NASA Astrophysics Data System (ADS)

Schwab, Christian; Spronck, Julien F. P.; Tokovinin, Andrei; Szymkowiak, Andrew; Giguere, Matthew; Fischer, Debra A.

2012-09-01

CHIRON is a fiber-fed Echelle spectrograph with observing modes for resolutions from 28,000 to 120,000, built primarily for measuring precise radial velocities (RVs). We present the instrument performance as determined during integration and commissioning. We discuss the PSF, the effect of glass inhomogeneity on the cross-dispersion prism, temperature stabilization, stability of the spectrum on the CCD, and detector characteristics. The RV precision is characterized, with an iodine cell or a ThAr lamp as the wavelength reference. Including all losses from the sky to the detector, the overall efficiency is about 6%; the dominant limitation is coupling losses into the fiber due to poor guiding.

The New Instrument Suite of the TSU/Fairborn 2m Automatic Spectroscopic Telescope

NASA Astrophysics Data System (ADS)

Muterspaugh, Matthew W.; Maxwell, T.; Williamson, M. W.; Fekel, F. C.; Ge, J.; Kelly, J.; Ghasempour, A.; Powell, S.; Zhao, B.; Varosi, F.; Schofield, S.; Liu, J.; Warner, C.; Jakeman, H.; Avner, L.; Swihart, S.; Harrison, C.; Fishler, D.

2014-01-01

Tied with the Liverpool Telescope as the world's largest fully robotic optical research telescope, Tennessee State University's (TSU) 2m Automatic Spectroscopic Telescope (AST) has recently been upgraded to improve performance and increase versatility by supporting multiple instruments. Its second-generation instrument head enables us to rapidly switch between any of up to twelve fibers optics, each of which can supply light to a different instrument. In 2013 construction was completed on a new temperature-controlled guest instrument building, and two new high resolution spectrographs were commissioned. The current set of instrumentation includes (1) the telescope's original R=30,000 echelle spectrograph (0.38--0.83 microns simultaneous), (2) a single order R=7,000 spectrograph centered at Ca H&K features, (3) a single-mode-fiber fed miniature echelle spectrograph (R=100,000; 0.48--0.62 microns simultaneous), (4) the University of Florida's EXPERT-3 spectrograph (R=100,000; 0.38--0.9 microns simultaneous; vacuum and temperature controlled) and (5) the University of Florida's FIRST spectrograph (R=70,000$; 0.8--1.35 or 1.4--1.8 microns simultaneous; vacuum and temperature controlled). Future instruments include the Externally Dispersed Interferometry (EDI) Testbed, a combination low resolution dispersed spectrograph and Fourier Transform Spectrograph. We welcome inquiries from the community in regards to observing access and/or proposals for future guest instruments.

VizieR Online Data Catalog: Abundance distribution of stars with planets (Bond+, 2006)

NASA Astrophysics Data System (ADS)

Bond, J. C.; Tinney, C. G.; Butler, R. P.; Jones, H. R. A.; Marcy, G. W.; Penny, A. J.; Carter, B. D.

2006-11-01

Spectroscopic observations of the target stars were obtained at the 3.9-m Anglo-Australian Telescope (AAT) between 1998 January and 2000 November as part of the AAPS. All of the spectra used were obtained with the University College London Echelle Spectrograph using the 31.6lines/mm echelle grating. (2 data files).

VizieR Online Data Catalog: Radial velocities of HD 96511, HR 7578, and KZ And (Fekel+, 2017)

NASA Astrophysics Data System (ADS)

Fekel, F. C.; Henry, G. W.; Tomkin, J.

2018-06-01

Our new spectroscopic observations of HD 96511, HR 7578, and KZ And were obtained at three observatories. The majority were acquired from 2003 through 2017 with the Tennessee State University 2 m automatic spectroscopic telescope (AST) and a fiber-fed echelle spectrograph. That telescope is part of Fairborn Observatory near Washington Camp in the Patagonia Mountains of southeastern Arizona (Eaton & Williamson 2004SPIE.5496..710E, 2007PASP..119..886E). From 2005 through 2011 we acquired additional spectrograms at the Kitt Peak National Observatory (KPNO) with the coude feed telescope and coude spectrograph. Most of the observations were obtained with a Texas Instruments (TI) CCD detector. Finally, at McDonald Observatory in 2005 and 2006 we collected four spectra with the 2.1 m telescope, the Sandiford Cassegrain echelle spectrograph (McCarthy et al. 1993PASP..105..881M), and a Reticon CCD. (5 data files).

VizieR Online Data Catalog: weak G-band stars abundances (Palacios+, 2016)

NASA Astrophysics Data System (ADS)

Palacios, A.; Jasniewicz, G.; Masseron, T.; Thevenin, F.; Itam-Pasquet, J.; Parthasarathy, M.

2016-05-01

Seventeen southern wGb stars were observed at La Silla, ESO Chile, with the high-efficiency Fiber-fed Extended Range Optical Spectrograph FEROS spectrograph mounted on the 2.2m telescope. FEROS is a bench-mounted, thermally controlled, prism-cross-dispersed echelle spectrograph, providing, in a single spectrogram spread over 39 orders, almost complete spectral coverage from ~350 to ~920nm at a resolution of 48000. The FEROS observations were carried out during an observing run between May 10 and 13, 2012. All these spectra were flat-fielded and calibrated by means of ThArNe exposures using standard processing tools available at ESO. In addition, two northern wGb stars, HD 18474 and HD 166208, were observed in service mode at the Observatoire du Pic du Midi, France, with the NARVAL spectrograph mounted on the Bernard Lyot 2.0m telescope. The NARVAL instrument consists of a bench-mounted cross-dispersed echelle spectrograph, fibre-fed from a Cassegrain-mounted polarimeter unit. It was used in its non-polarimetric mode; it provided almost complete spectral coverage from ~375 to ~1050nm at a resolution of 75000 in a single spectrogram spread over 40 orders. (6 data files).

NRES: The Network of Robotic Echelle Spectrographs

NASA Astrophysics Data System (ADS)

Siverd, Robert; Brown, Timothy M.; Henderson, Todd; Hygelund, John; Barnes, Stuart; Bowman, Mark; De Vera, Jon; Eastman, Jason D.; Kirby, Annie; Norbury, Martin; Smith, Cary; Taylor, Brook; Tufts, Joseph; Van Eyken, Julian C.

2017-06-01

Las Cumbres Observatory (LCO) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of four to six identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a Thorium-Argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to ten 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 11 or 12. Following a few months of on-sky evaluation at our BPL test facility, the first spectrograph unit was shipped to CTIO in late 2016 and installed in March 2017. Barring serious complications, we expect regular scheduled science observing to begin in mid-2017. Three additional units are in building or testing phases and slated for deployment in late 2017. Acting in concert, these four spectrographs will provide a new, unique facility for stellar characterization and precise radial velocities. We will briefly overview the LCO telescope network, the NRES spectrograph design, the advantages it provides, and development challenges we encountered along the way. We will further discuss real-world performance from our first unit, initial science results, and the ongoing software development effort needed to automate such a facility for a wide array of science cases.

Deep echelle spectrophotometry of S 311, a Galactic HII region located outside the solar circle

NASA Astrophysics Data System (ADS)

García-Rojas, J.; Esteban, C.; Peimbert, A.; Peimbert, M.; Rodríguez, M.; Ruiz, M. T.

2005-09-01

We present echelle spectrophotometry of the Galactic HII region S 311. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3100-10400 Årange. We have measured the intensities of 263 emission lines; 178 are permitted lines of H0, D0 (deuterium), He0, C0, C+, N0, N+, O0, O+, S+, Si0, Si+, Ar0 and Fe0; some of them are produced by recombination and others mainly by fluorescence. Physical conditions have been derived using different continuum- and line-intensity ratios. We have derived He+, C++ and O++ ionic abundances from pure recombination lines as well as abundances from collisionally excited lines for a large number of ions of different elements. We have obtained consistent estimations of t2 applying different methods. We have found that the temperature fluctuations paradigm is consistent with the Te(HeI) versus Te(HI) relation for HII regions, in contrast with what has been found for planetary nebulae. We report the detection of deuterium Balmer lines up to Dδ in the blue wings of the hydrogen lines, whose excitation mechanism seems to be continuum fluorescence.

The third flight of CHESS: Preliminary analysis of interstellar H2 on the β1 Sco sightline

NASA Astrophysics Data System (ADS)

Kruczek, Nick; France, Kevin

2018-01-01

We describe the scientific motivation and technical development of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS), focusing on the preliminary science results for the third launch of the payload (CHESS-3). CHESS is a far ultraviolet rocket-borne instrument designed to study the atomic-to-molecular transitions within translucent cloud regions in the interstellar medium. CHESS is an objective echelle spectrograph, which uses a mechanically-ruled echelle and a powered (f/12.4) cross-dispersing grating, and is designed to achieve a resolving power R > 100,000 over the band pass λλ 1000-1600 Å. CHESS-3 launched on 14 June 2017 aboard NASA/CU sounding rocket mission 36.323 UG. The target for the flight was β1 Sco, a B1V star with a sightline that is likely sampling translucent material. We present flight results of interstellar molecular hydrogen excitation, including initial measurements of the column density and temperature, on the sightline.

VizieR Online Data Catalog: CARMENES radial velocity curves of 7 M-dwarf (Trifonov+, 2018)

NASA Astrophysics Data System (ADS)

Trifonov, T.; Kuerster, M.; Zechmeister, M.; Tal-Or, L.; Caballero, J. A.; Quirrenbach, A.; Amado, P. J.; Ribas, I.; Reiners, A.; Reffert, S.; Dreizler, S.; Hatzes, A. P.; Kaminski, A.; Launhardt, R.; Henning, T.; Montes, D.; Bejar, V. J. S.; Mundt, R.; Pavlov, A.; Schmitt, J. H. M. M.; Seifert, W.; Morales, J. C.; Nowak, G.; Jeffers, S. V.; Rodriguez-Lopez, C.; Del Burgo, C.; Anglada-Escude, G.; Lopez-Santiago, J.; Mathar, R. J.; Ammler-von Eiff, M.; Guenther, E. W.; Barrado, D.; Gonzalez Hernandez, J. I.; Mancini, L.; Stuermer, J.; Abril, M.; Aceituno, J.; Alonso-Floriano, F. J.; Antona, R.; Anwand-Heerwart, H.; Arroyo-Torres, B.; Azzaro, M.; Baroch, D.; Bauer, F. F.; Becerril, S.; Benitez, D.; Berdinas, Z. M.; Bergond, G.; Bluemcke, M.; Brinkmoeller, M.; Cano, J.; Cardenas Vazquez, M. C.; Casal, E.; Cifuentes, C.; Claret, A.; Colome, J.; Cortes-Contreras, M.; Czesla, S.; Diez-Alonso, E.; Feiz, C.; Fernandez, M.; Ferro, I. M.; Fuhrmeister, B.; Galadi-Enriquez, D.; Garcia-Piquer, A.; Garcia Vargas, M. L.; Gesa, L.; Gomez Galera, V.; Gonzalez-Peinado, R.; Groezinger, U.; Grohnert, S.; Guardia, J.; Guijarro, A.; de Guindos, E.; Gutierrez-Soto, J.; Hagen, H.-J.; Hauschildt, P. H.; Hedrosa, R. P.; Helmling, J.; Hermelo, I.; Hernandez Arabi, R.; Hernandez Castano, L.; Hernandez Hernando, F.; Herrero, E.; Huber, A.; Huke, P.; Johnson, E.; de Juan, E.; Kim, M.; Klein, R.; Klueter, J.; Klutsch, A.; Lafarga, M.; Lampon, M.; Lara, L. M.; Laun, W.; Lemke, U.; Lenzen, R.; Lopez Del Fresno, M.; Lopez-Gonzalez, J.; Lopez-Puertas, M.; Lopez Salas, J. F.; Luque, R.; Magan Madinabeitia, H.; Mall, U.; Mandel, H.; Marfil, E.; Marin Molina, J. A.; Maroto Fernandez, D.; Martin, E. L.; Martin-Ruiz, S.; Marvin, C. J.; Mirabet, E.; Moya, A.; Moreno-Raya, M. E.; Nagel, E.; Naranjo, V.; Nortmann, L.; Ofir, A.; Oreiro, R.; Palle, E.; Panduro, J.; Pascual, J.; Passegger, V. M.; Pedraz, S.; Perez-Calpena, A.; Perez Medialdea, D.; Perger, M.; Perryman, M. A. C.; Pluto, M.; Rabaza, O.; Ramon, A.; Rebolo, R.; Redondo, P.; Reinhardt, S.; Rhode, P.; Rix, H.-W.; Rodler, F.; Rodriguez, E.; Rodriguez Trinidad, A.; Rohlo, R.-R.; Rosich, A.; Sadegi, S.; Sanchez-Blanco, E.; Sanchez Carrasco, M. A.; Sanchez-Lopez, A.; Sanz-Forcada, J.; Sarkis, P.; Sarmiento, L. F.; Schaefer, S.; Schiller, J.; Schoefer, P.; Schweitzer, A.; Solano, E.; Stahl, O.; Strachan, J. B. P.; Suarez, J. C.; Tabernero, H. M.; Tala, M.; Tulloch, S. M.; Veredas, G.; Vico Linares, J. I.; Vilardel, F.; Wagner, K.; Winkler, J.; Woltho, V.; Xu, W.; Yan, F.; Zapatero Osorio, M. R.

2017-10-01

The two CARMENES spectrographs are grism cross-dispersed, white pupil, echelle spectrograph working in quasi-Littrow mode using a two-beam, two-slice image slicer. The visible spectrograph covers the wavelength range from 0.52um to 1.05um with 61 orders, a resolving power of R=94600, and a mean sampling of 2.8 pixels per resolution element. The data presented in this paper were taken during the early phase of operation of the CARMENES visible-light spectrograph. (8 data files).

Data reductions and data quality for the high resolution spectrograph on the Southern African Large Telescope

NASA Astrophysics Data System (ADS)

Crawford, S. M.; Crause, Lisa; Depagne, Éric; Ilkiewicz, Krystian; Schroeder, Anja; Kuhn, Rudolph; Hettlage, Christian; Romero Colmenaro, Encarni; Kniazev, Alexei; Väisänen, Petri

2016-08-01

The High Resolution Spectrograph (HRS) on the Southern African Large Telescope (SALT) is a dual beam, fiber-fed echelle spectrograph providing high resolution capabilities to the SALT observing community. We describe the available data reduction tools and the procedures put in place for regular monitoring of the data quality from the spectrograph. Data reductions are carried out through the pyhrs package. The data characteristics and instrument stability are reported as part of the SALT Dashboard to help monitor the performance of the instrument.

Precision stellar radial velocity measurements with FIDEOS at the ESO 1-m telescope of La Silla

NASA Astrophysics Data System (ADS)

Vanzi, L.; Zapata, A.; Flores, M.; Brahm, R.; Tala Pinto, M.; Rukdee, S.; Jones, M.; Ropert, S.; Shen, T.; Ramirez, S.; Suc, V.; Jordán, A.; Espinoza, N.

2018-07-01

We present results from the commissioning and early science programs of FIbre Dual Echelle Optical Spectrograph (FIDEOS), the new high-resolution echelle spectrograph developed at the Centre of Astro Engineering of Pontificia Universidad Catolica de Chile, and recently installed at the ESO 1-m telescope of La Silla. The instrument provides spectral resolution R ˜ 43 000 in the visible spectral range 420-800 nm, reaching a limiting magnitude of 11 in V band. Precision in the measurement of radial velocity is guaranteed by light feeding with an octagonal optical fibre, suitable mechanical isolation, thermal stabilization, and simultaneous wavelength calibration. Currently the instrument reaches radial velocity stability of ˜8 m s-1 over several consecutive nights of observation.

The ICE spectrograph for PEPSI at the LBT: preliminary optical design

NASA Astrophysics Data System (ADS)

Pallavicini, Roberto; Zerbi, Filippo M.; Spano, Paolo; Conconi, Paolo; Mazzoleni, Ruben; Molinari, Emilio; Strassmeier, Klaus G.

2003-03-01

We present a preliminary design study for a high-resolution echelle spectrograph (ICE) to be used with the spectropolarimeter PEPSI under development at the LBT. In order to meet the scientific requirements and take full advantage of the peculiarities of the LBT (i.e. the binocular nature and the adaptive optics capabilities), we have designed a fiber-fed bench mounted instrument for both high resolution (R ≍ 100,000; non-AO polarimetric and integral light modes) and ultra-high resolution (R ≍ 300,000; AO integral light mode). In both cases, 4 spectra per order (two for each primary mirror) shall be accomodated in a 2-dimensional cross dispersed echelle format. In order to obtain a resolution-slit product of ≍ 100,000 as required by the science case, we have considered two alternative designs, one with two R4 echelles in series and the other with a sigle R4 echelle and fiber slicing. A white-pupil design, VPH cross-dispersers and two cameras of different focal length for the AO and non-AO modes are adopted in both cases. It is concluded that the single-echelle fiber-slicer solution has to be preferred in terms of performances, complexity and cost. It can be implemented at the LBT in two phases, with the long-camera AO mode added in a second phase depending on the availability of funds and the time-scale for implementation of the AO system.

The third flight of the Colorado high-resolution echelle stellar spectrograph (CHESS): improvements, calibrations, and preliminary results

NASA Astrophysics Data System (ADS)

Kruczek, Nicholas; Nell, Nicholas; France, Kevin; Hoadley, Keri; Fleming, Brian; Kane, Robert; Ulrich, Stefan; Egan, Arika; Beatty, Dawson

2017-08-01

In this proceeding, we describe the scientific motivation and technical development of the Colorado HighResolution Echelle Stellar Spectrograph (CHESS), focusing on the hardware advancements and testing of components for the third launch of the payload (CHESS-3). CHESS is a far ultraviolet rocket-borne instrument designed to study the atomic-to-molecular transitions within translucent cloud regions in the interstellar medium. CHESS is an objective echelle spectrograph, which uses a mechanically-ruled echelle and a powered (f/12.4) crossdispersing grating, and is designed to achieve a resolving power R > 100,000 over the bandpass λλ 1000-1600 Å. Results from final efficiency and reflectivity measurements for the optical components of CHESS-3 are presented. An important role of sounding rocket experiments is the testing and verification of the space flight capabilities of experimental technologies. CHESS-3 utilizes a 40mm-diameter cross-strip anode microchannel plate detector fabricated by Sensor Sciences LLC, capable of achieving high spatial resolution and a high global count rate (˜1 MHz). We present pre-flight laboratory spectra and calibration results, including wavelength solution and resolving power of the instrument. The fourth launch of CHESS (CHESS-4) will demonstrate a δ-doped CCD, assembled in collaboration with the Microdevices Laboratory at JPL and Arizona State University. In support of CHESS-4, the CHESS-3 payload included a photomultiplier tube, used as a secondary confirmation of the optical alignment of the payload during flight. CHESS-3 launched on 26 June 2017 aboard NASA/CU sounding rocket mission 36.323 UG. We present initial flight results for the CHESS-3 observation of the β1 Scorpii sightline.

Design of FHiRE: the Fiber High Resolution Echelle Spectrograph

NASA Astrophysics Data System (ADS)

Pierce, Michael J.; McLane, Jacob N.; Pilachowski, C. A.; Kobulnicky, Henry; Jang-Condell, Hannah

2018-01-01

The enormous success of the Kepler mission in the discovery of transiting exoplanets implies that the majority of stars have planetary systems. NASA's upcomming Transiting Exoplanet Survey Satellite (TESS) is designed to survey the brightest stars over the entire sky, systems that are accessible to spectroscopic follow-up with mid-sized telescopes. We have undertaken the development of a precision radial velocity spectrograph with the goal of providing ground-based suppoert for TESS. The instrument, known as FHiRE (Fiber High Resolution Echelle spectrograph), is being developed in collaboration with Indiana University and will deployed at the 2.3-meter telescope of the Wyoming InfraRed Observatory (WIRO). FHiRE features a traditional white pupil echelle design with R ~ 60,000 that is fed via two optical fibers from the telescope. Both the science fiber and a simultaneously sampled Thorium-Argon comparison fiber will make use of double mode scramblers. FHiRE itself will be housed within a vacuum enclosure in order to minimize any temperatue variations of the instrument and maximize its radial velocity precision. Together, these two features should enable FHiRE to reach a long-term velocity precision of < 1 m/s. We present the design of FHiRE and its expected performance. In a companion poster (Jang-Condell et al.) we will present the exoplanet science goals of the project.

bHROS: A New High-Resolution Spectrograph Available on Gemini South

NASA Astrophysics Data System (ADS)

Margheim, S. J.; Gemini bHROS Team

2005-12-01

The Gemini bench-mounted High-Resolution Spectrograph (bHROS) is available for science programs beginning in 2006A. bHROS is the highest resolution (R=150,000) optical echelle spectrograph optimized for use on an 8-meter telescope. bHROS is fiber-fed via GMOS-S from the Gemini South focal plane and is available in both a dual-fiber Object/Sky mode and a single (larger) Object-only mode. Instrument characteristics and sample data taken during commissioning will be presented.

Can we use adaptive optics for UHR spectroscopy with PEPSI at the LBT?

NASA Astrophysics Data System (ADS)

Sacco, Germano G.; Pallavicini, Roberto; Spano, Paolo; Andersen, Michael; Woche, Manfred F.; Strassmeier, Klaus G.

2004-10-01

We investigate the potential of using adaptive optics (AO) in the V, R, and I bands to reach ultra-high resolution (UHR, R >= 200,000) in echelle spectrographs at 8-10m telescopes. In particular, we investigate the possibility of implementing an UHR mode for the fiber-fed spectrograph PEPSI (Potsdam Echelle Polarimetric and Spectrographic Instrument) being developed for the Large Binocular Telescope (LBT). By simulating the performances of the advanced AO system that will be available at first light at the LBT, and by using first-order estimates of the spectrograph performances, we calculate the total efficiency and signal to noise ratio (SNR) of PEPSI in the AO mode for stars of different magnitudes, different fiber core sizes, and different fractions of incident light diverted to the wavefront sensor. We conclude that AO can provide a significant advantage, of up to a factor ~2 in the V, R and I bands, for stars brighter than mR ~ 12 - 13. However, if these stars are observed at UHR in non-AO mode, slit losses caused by the need to use a very narrow slit can be compensated more effectively by the use of image slicers.

Instrumentation progress at the Giant Magellan Telescope project

NASA Astrophysics Data System (ADS)

Jacoby, George H.; Bernstein, R.; Bouchez, A.; Colless, M.; Crane, Jeff; DePoy, D.; Espeland, B.; Hare, Tyson; Jaffe, D.; Lawrence, J.; Marshall, J.; McGregor, P.; Shectman, Stephen; Sharp, R.; Szentgyorgyi, A.; Uomoto, Alan; Walls, B.

2016-08-01

Instrument development for the 24m Giant Magellan Telescope (GMT) is described: current activities, progress, status, and schedule. One instrument team has completed its preliminary design and is currently beginning its final design (GCLEF, an optical 350-950 nm, high-resolution and precision radial velocity echelle spectrograph). A second instrument team is in its conceptual design phase (GMACS, an optical 350-950 nm, medium resolution, 6-10 arcmin field, multi-object spectrograph). A third instrument team is midway through its preliminary design phase (GMTIFS, a near-IR YJHK diffraction-limited imager/integral-field-spectrograph), focused on risk reduction prototyping and design optimization. A fourth instrument team is currently fabricating the 5 silicon immersion gratings needed to begin its preliminary design phase (GMTNIRS, a simultaneous JHKLM high-resolution, AO-fed, echelle spectrograph). And, another instrument team is focusing on technical development and prototyping (MANIFEST, a facility robotic, multifiber feed, with a 20 arcmin field of view). In addition, a medium-field (6 arcmin, 0.06 arcsec/pix) optical imager will support telescope and AO commissioning activities, and will excel at narrow-band imaging. In the spirit of advancing synergies with other groups, the challenges of running an ELT instrument program and opportunities for cross-ELT collaborations are discussed.

The GMT-Consortium Large Earth Finder (G-CLEF) : An Optical Echelle Spectrograph for the Giant Magellan Telescope (GMT) with Multi-Object Spectroscopy (MOS) Capability

NASA Astrophysics Data System (ADS)

Szentgyorgyi, Andrew

2017-09-01

"The GMT-Consortium Large Earth Finder (G-CLEF) is an optical band echelle spectrograph that has been selected as the first light instrument for the Giant Magellan Telescope (GMT). G-CLEF is a general purpose, high dispersion instrument that is fiber fed and capable of extremely precise radial velocity (PRV) measurements. G-CLEF will have a novel multi-object spectroscopy (MOS) capability that will be useful for a number of exoplanet science programs. I describe the general properties of G-CLEF and the systems engineering analyses, especially for PRV, that drove the current G-CLEF design. The requirements for calibration of the MOS channel are presented along with several novel approaches for achieving moderate radial velocity precision in the MOS mode."

VizieR Online Data Catalog: Keck+Magellan survey for LLSs. III. (Prochaska+, 2015)

NASA Astrophysics Data System (ADS)

Prochaska, J. X.; O'Meara, J. M.; Fumagalli, M.; Bernstein, R. A.; Burles, S. M.

2016-01-01

The sample presented in this manuscript is intended to be a nearly all-inclusive set of Lyman Limit Systems (LLSs) discovered in the high-dispersion (echelle or echellette; R>5000) spectra that we have gathered at the Keck and Magellan telescopes. Regarding Keck, we have examined all of the data obtained by Principal Investigators (PIs) A. M. Wolfe and J. X. Prochaska at the W. M. Keck Observatory through 2012 April, and from PIs Burles, O'Meara, Bernstein, and Fumagalli at Magellan through 2012 July. We also include the Keck spectra analyzed by Penprase et al. (2010, J/ApJ/721/1). We present data obtained at the W. M. Keck and Las Campanas Observatories using the twin 10m Keck I and Keck II telescopes and the twin 6.5m Baade and Clay telescopes. Altogether, we used four spectrometers: (1) the High Resolution Echelle Spectrometer (HIRES); (2) the Echellette Spectrograph and Imager (ESI); (3) the Magellan Inamori Kyocera Echelle (MIKE); and (4) the Magellan Echellette Spectrograph (MagE). Observing logs for the HIRES and MIKE spectra are provided in Tables 1 and 2. (5 data files).

NRES: The Network of Robotic Echelle Spectrographs

NASA Astrophysics Data System (ADS)

Siverd, Robert; Brown, Tim; Henderson, Todd; Hygelund, John; Barnes, Stuart; de Vera, Jon; Eastman, Jason; Kirby, Annie; Smith, Cary; Taylor, Brook; Tufts, Joseph; van Eyken, Julian

2018-01-01

Las Cumbres Observatory (LCO) is building the Network of Robotic Echelle Spectrographs (NRES), which will consist of four (up to six in the future) identical, optical (390 - 860 nm) high-precision spectrographs, each fiber-fed simultaneously by up to two 1-meter telescopes and a Thorium-Argon calibration source. We plan to install one at up to 6 observatory sites in the Northern and Southern hemispheres, creating a single, globally-distributed, autonomous spectrograph facility using up to ten 1-m telescopes. Simulations suggest we will achieve long-term radial velocity precision of 3 m/s in less than an hour for stars brighter than V = 11 or 12 once the system reaches full capability. Acting in concert, these four spectrographs will provide a new, unique facility for stellar characterization and precise radial velocities.Following a few months of on-sky evaluation at our BPL test facility, the first spectrograph unit was shipped to CTIO in late 2016 and installed in March 2017. After several more months of additional testing and commissioning, regular science operations began with this node in September 2017. The second NRES spectrograph was installed at McDonald Observatory in September 2017 and released to the network after its own brief commissioning period, extending spectroscopic capability to the Northern hemisphere. The third NRES spectrograph was installed at SAAO in November 2017 and released to our science community just before year's end. The fourth NRES unit shipped in October and is currently en route to Wise Observatory in Israel with an expected release to the science community in early 2018.We will briefly overview the LCO telescope network, the NRES spectrograph design, the advantages it provides, and development challenges we encountered along the way. We will further discuss real-world performance from our first three units, initial science results, and the ongoing software development effort needed to automate such a facility for a wide array of science cases.

The assembly, calibration, and preliminary results from the Colorado high-resolution Echelle stellar spectrograph (CHESS)

NASA Astrophysics Data System (ADS)

Hoadley, Keri; France, Kevin; Nell, Nicholas; Kane, Robert; Schultz, Ted; Beasley, Matthew; Green, James; Kulow, Jen; Kersgaard, Eliot; Fleming, Brian

2014-07-01

The Colorado High-resolution Echelle Stellar Spectrograph (CHESS) is a far ultraviolet (FUV) rocket-borne experiment designed to study the atomic-to-molecular transitions within translucent interstellar clouds. CHESS is an objective echelle spectrograph operating at f/12.4 and resolving power of 120,000 over a band pass of 100 - 160 nm. The echelle flight grating is the product of a research and development project with LightSmyth Inc. and was coated at Goddard Space Flight Center (GSFC) with Al+LiF. It has an empirically-determined groove density of 71.67 grooves/mm. At the Center for Astrophysics and Space Astronomy (CASA) at the University of Colorado (CU), we measured the efficiencies of the peak and adjacent dispersion orders throughout the 90 - 165 nm band pass to characterize the behavior of the grating for pre-flight calibrations and to assess the scattered-light behavior. The crossdispersing grating, developed and ruled by Horiba Jobin-Yvon, is a holographically-ruled, low line density (351 grooves/mm), powered optic with a toroidal surface curvature. The CHESS cross-disperser was also coated at GSFC; Cr+Al+LiF was deposited to enhance far-UV efficiency. Results from final efficiency and reflectivity measurements of both optics are presented. We utilize a cross-strip anode microchannel plate (MCP) detector built by Sensor Sciences to achieve high resolution (25 μm spatial resolution) and data collection rates (~ 106 photons/second) over a large format (40mm round, digitized to 8k x 8k) for the first time in an astronomical sounding rocket flight. The CHESS instrument was successfully launched from White Sands Missile Range on 24 May 2014. We present pre-flight sensitivity, effective area calculations, lab spectra and calibration results, and touch on first results and post-flight calibration plans.

The GMT-Consortium Large Earth Finder (G-CLEF): an optical Echelle spectrograph for the Giant Magellan Telescope (GMT)

NASA Astrophysics Data System (ADS)

Szentgyorgyi, Andrew; Baldwin, Daniel; Barnes, Stuart; Bean, Jacob; Ben-Ami, Sagi; Brennan, Patricia; Budynkiewicz, Jamie; Chun, Moo-Young; Conroy, Charlie; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Foster, Jeff; Frebel, Anna; Gauron, Thomas; Guzmán, Dani; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jordan, Andres; Kim, Jihun; Kim, Kang-Miin; Mendes de Oliveira, Claudia Mendes; Lopez-Morales, Mercedes; McCracken, Kenneth; McMuldroch, Stuart; Miller, Joseph; Mueller, Mark; Oh, Jae Sok; Onyuksel, Cem; Ordway, Mark; Park, Byeong-Gon; Park, Chan; Park, Sung-Joon; Paxson, Charles; Phillips, David; Plummer, David; Podgorski, William; Seifahrt, Andreas; Stark, Daniel; Steiner, Joao; Uomoto, Alan; Walsworth, Ronald; Yu, Young-Sam

2016-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) will be a cross-dispersed, optical band echelle spectrograph to be delivered as the first light scientific instrument for the Giant Magellan Telescope (GMT) in 2022. G-CLEF is vacuum enclosed and fiber-fed to enable precision radial velocity (PRV) measurements, especially for the detection and characterization of low-mass exoplanets orbiting solar-type stars. The passband of G-CLEF is broad, extending from 3500Å to 9500Å. This passband provides good sensitivity at blue wavelengths for stellar abundance studies and deep red response for observations of high-redshift phenomena. The design of G-CLEF incorporates several novel technical innovations. We give an overview of the innovative features of the current design. G-CLEF will be the first PRV spectrograph to have a composite optical bench so as to exploit that material's extremely low coefficient of thermal expansion, high in-plane thermal conductivity and high stiffness-to-mass ratio. The spectrograph camera subsystem is divided into a red and a blue channel, split by a dichroic, so there are two independent refractive spectrograph cameras. The control system software is being developed in model-driven software context that has been adopted globally by the GMT. G-CLEF has been conceived and designed within a strict systems engineering framework. As a part of this process, we have developed a analytical toolset to assess the predicted performance of G-CLEF as it has evolved through design phases.

Second generation spectrograph for the Hubble Space Telescope

NASA Astrophysics Data System (ADS)

Woodgate, B. E.; Boggess, A.; Gull, T. R.; Heap, S. R.; Krueger, V. L.; Maran, S. P.; Melcher, R. W.; Rebar, F. J.; Vitagliano, H. D.; Green, R. F.; Wolff, S. C.; Hutchings, J. B.; Jenkins, E. B.; Linsky, J. L.; Moos, H. W.; Roesler, F.; Shine, R. A.; Timothy, J. G.; Weistrop, D. E.; Bottema, M.; Meyer, W.

1986-01-01

The preliminary design for the Space Telescope Imaging Spectrograph (STIS), which has been selected by NASA for definition study for future flight as a second-generation instrument on the Hubble Space Telescope (HST), is presented. STIS is a two-dimensional spectrograph that will operate from 1050 A to 11,000 A at the limiting HST resolution of 0.05 arcsec FWHM, with spectral resolutions of 100, 1200, 20,000, and 100,000 and a maximum field-of-view of 50 x 50 arcsec. Its basic operating modes include echelle model, long slit mode, slitless spectrograph mode, coronographic spectroscopy, photon time-tagging, and direct imaging. Research objectives are active galactic nuclei, the intergalactic medium, global properties of galaxies, the origin of stellar systems, stelalr spectral variability, and spectrographic mapping of solar system processes.

VizieR Online Data Catalog: IRAS 22023+5249 spectroscopy (Sarkar+, 2012)

NASA Astrophysics Data System (ADS)

Sarkar, G.; Garcia-Hernandez, D. A.; Parthasarathy, M.; Manchado, A.; Garcia-Lario, P.; Takeda, Y.

2012-10-01

IRAS 22023+5249 was observed on 14 July 2001 using the Utrecht Echelle Spectrograph on the 4.2m William Herschel Telescope at the Roque de los Muchachos Observatory in La Palma (Spain). (3 data files).

Affordable spectroscopy for 1m-class telescopes: recent developments and applications

NASA Astrophysics Data System (ADS)

Csák, B.; Kovács, J.; Szabó, Gy. M.; Kiss, L. L.; Dózsa, Á.; Sódor, Á.; Jankovics, I.

2014-03-01

Doppler observations of exoplanet systems have been a very expensive technique, mainly due to the high costs of high-resolution stable spectrographs. Recent advances in instrumentation enable affordable Doppler planet detections with surprisingly small optical telescopes. We investigate the possibility of measuring Doppler reflex motion of planet hosting stars with small-aperture telescopes that have traditionally been neglected for this kind of studies. After thoroughly testing the recently developed and commercially available Shelyak eShel echelle spectrograph, we demonstrated that it is routinely possible to achieve velocity precision at the 100 m s-1 level, reaching down to ¬± 50 m s-1 for the best cases. We describe our off-the-shelf instrumentation, including a new 0.5m RC telescope at the Gothard Astrophysical Observatory of Loránd E&ötv&ös University equipped with an intermediate resolution fiber-fed echelle spectrograph. We present some follow-up radial velocity measurements of planet hosting stars and point out that updating the orbital solution of Doppler-planets is a very important task that can be fulfilled with sub-meter sized optical telescopes without requesting very expensive telescope times on 2—4 m (or larger) class telescopes.

WIYN bench upgrade: a revitalized spectrograph

NASA Astrophysics Data System (ADS)

Bershady, M.; Barden, S.; Blanche, P.-A.; Blanco, D.; Corson, C.; Crawford, S.; Glaspey, J.; Habraken, S.; Jacoby, G.; Keyes, J.; Knezek, P.; Lemaire, P.; Liang, M.; McDougall, E.; Poczulp, G.; Sawyer, D.; Westfall, K.; Willmarth, D.

2008-07-01

We describe the redesign and upgrade of the versatile fiber-fed Bench Spectrograph on the WIYN 3.5m telescope. The spectrograph is fed by either the Hydra multi-object positioner or integral-field units (IFUs) at two other ports, and can be configured with an adjustable camera-collimator angle to use low-order and echelle gratings. The upgrade, including a new collimator, charge-coupled device (CCD) and modern controller, and volume-phase holographic gratings (VPHG), has high performance-to-cost ratio by combining new technology with a system reconfiguration that optimizes throughput while utilizing as much of the existing instrument as possible. A faster, all-refractive collimator enhances throughput by 60%, nearly eliminates the slit-function due to vignetting, and improves image quality to maintain instrumental resolution. Two VPH gratings deliver twice the diffraction efficiency of existing surface-relief gratings: A 740 l/mm grating (float-glass and post-polished) used in 1st and 2nd-order, and a large 3300 l/mm grating (spectral resolution comparable to the R2 echelle). The combination of collimator, high-quantum efficiency (QE) CCD, and VPH gratings yields throughput gain-factors of up to 3.5.

A spectrographic study of the aurora and the relation to solar wind pressure pulses.

NASA Astrophysics Data System (ADS)

Stockton-Chalk, A. B.; Lanchester, B. S.; Ivchenko, N.; Lummerzheim, D.; Throp, K.

SIF (Spectrographic Imaging Facility) is a Southampton University / University College London collaboration. The platform consists of a High Throughput Imaging Echelle Spectrograph, HiTIES, two photometers and a narrow angle auroral imager. The spectrograph has a mosaic filter; each of the three spectral panels are centred over/near important spectral features: Hbeta (486.1nm), N2+(470.9nm), N2+(465.2nm), thus allowing studies of proton and electron aurorae. The platform has been successfully deployed in Svalbard since November 1999. The purpose of the experiment was to take spectrographic measurements to study the relationship between proton and electron precipitation and to understand the nature of the precipitating spectrum of protons, both in energy and angular distributions. We present a study of the aurora observed in relation to solar wind pressure pulses.

High resolution spectrograph. [for LST

NASA Technical Reports Server (NTRS)

Peacock, K.

1975-01-01

The high resolution spectrograph (HRS) is designed to be used with the Large Space Telescope (LST) for the study of spectra of point and extended targets in the spectral range 110 to 410 nm. It has spectral resolutions of 1,000; 30,000; and 100,000 and has a field of view as large as 10 arc sec. The spectral range and resolution are selectable using interchangeable optical components and an echelle spectrograph is used to display a cross dispersed spectrum on the photocathode of either of 2 SEC orthicon image tubes. Provisions are included for wavelength calibration, target identification and acquisition and thermal control. The system considerations of the instrument are described.

Achieving the resolution of the spectrograph of the 6m large Azimuthal telescope

NASA Astrophysics Data System (ADS)

Sazonenko, Dmitrii; Kukushkin, Dmitrii; Bakholdin, Alexey; Valyavin, Gennady

2016-08-01

Special Astrophysical Observatory of Russian Academy of Sciences (SAO RAS) creates a spectrograph with high spectral resolution for the 6-meter telescope. The spectrograph consists of a mobile unit located at the focus of the telescope's main mirror, a stationary part located under the telescope and optical fibers which transmit light from the mobile part to the stationary one. The spectral resolution of the stationary part should be R=100000. To achieve such a value, the scheme has two spectral elements, with cross-dispersion. The main spectral element is an echelle grating. The second spectral element is a prism with a diffraction grating on one facet.

VizieR Online Data Catalog: NGC5897 red giant abundances (Koch+, 2014)

NASA Astrophysics Data System (ADS)

Koch, A.; McWilliam, A.

2014-03-01

Our observations were performed with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph at the 6.5-m Magellan2/Clay Telescope at Las Campanas Observatory, Chile. The data were gathered over four nights in May 2013. (2 data files).

Imaging spectroscopy of Mars in the thermal infrared: seasonal variations of H2O2 and mapping of the D/H ratio

NASA Astrophysics Data System (ADS)

Encrenaz, Therese; DeWitt, Curtis; Richter, Matthew; Greathouse, Thomas; Fouchet, Thierry; Lefevre, Franck; Montmessin, Franck; Forget, Francois; Bezard, Bruno; Atreya, Sushil

2017-04-01

Since 2002, we have been monitoring the spatial distribution and the seasonal variations of H2O2 on Mars, using high-resolution imaging spectroscopy with the Texas Echelon Cross Echelle Spectrograph (TEXES) at the Infrared Telescope Facility (IRTF) at Maunakea Observatory (Hawaii). These observations have shown that a better agreement with global climate models is obtained when heterogeneous chemistry is introduced in the photochemical model (Encrenaz et al. 2015, AA 578, A127). In addition, in April 2014, we have obtained a map of D/H on Mars using the Echelon Cross Echelle Spectrograph (EXES) aboard the stratospheric Observatory for Infrared Astronomy (SOFIA; Encrenaz et al. 2015, AA 586, A62). In 2016, new observations have been obtained on H2O2 with TEXES and on D/H with EXES, allowing us to better analyze the seasonal variations of these parameters. These data will be presented and compared with previous measurements.

Spectroscopic Instrumentation in Undergraduate Astronomy Laboratories

NASA Astrophysics Data System (ADS)

Ludovici, Dominic; Mutel, Robert Lucien; Lang, Cornelia C.

2017-01-01

We have designed and built two spectrographs for use in undergraduate astronomy laboratories at the University of Iowa. The first, a low cost (appx. $500) low resolution (R ~ 150 - 300) grating-prism (grism) spectrometer consists of five optical elements and is easily modified to other telescope optics. The grism spectrometer is designed to be used in a modified filter wheel. This type of spectrometer allows students to undertake projects requiring sensitive spectral measurements, such as determining the redshifts of quasars. The second instrument is a high resolution (R ~ 8000), moderate cost (appx. $5000) fiber fed echelle spectrometer. The echelle spectrometer will allow students to conduct Doppler measurements such as those used to study spectroscopic binaries. Both systems are designed to be used with robotic telescope systems. The availability of 3D printing enables both of these spectrographs to be constructed in hands-on instrumentation courses where students build and commission their own instruments. Additionally, these instruments enable introductory majors and non-majors laboratory students to gain experience conducting their own spectroscopic observations.

Optical design of the PEPSI high-resolution spectrograph at LBT

NASA Astrophysics Data System (ADS)

Andersen, Michael I.; Spano, Paolo; Woche, Manfred; Strassmeier, Klaus G.; Beckert, Erik

2004-09-01

PEPSI is a high-resolution, fiber fed echelle spectrograph with polarimetric capabilities for the LBT. In order to reach a maximum resolution R=120.000 in polarimetric mode and 300.000 in integral light mode with high efficiency in the spectral range 390-1050~nm, we designed a white-pupil configuration with Maksutov collimators. Light is dispersed by an R4 31.6 lines/mm monolithic echelle grating mosaic and split into two arms through dichroics. The two arms, optimized for the spectral range 390-550~nm and 550-1050~nm, respectively, consist of Maksutov transfer collimators, VPH-grism cross dispersers, optimized dioptric cameras and 7.5K x 7.5K 8~μ CCDs. Fibers of different core sizes coupled to different image-slicers allow a high throughput, comparable to that of direct feed instruments. The optical configuration with only spherical and cylindrical surfaces, except for one aspherical surface in each camera, reduces costs and guarantees high optical quality. PEPSI is under construction at AIP with first light expected in 2006.

A reduction package for cross-dispersed echelle spectrograph data in IDL

NASA Astrophysics Data System (ADS)

Hall, Jeffrey C.; Neff, James E.

1992-12-01

We have written in IDL a data reduction package that performs reduction and extraction of cross-dispersed echelle spectrograph data. The present package includes a complete set of tools for extracting data from any number of spectral orders with arbitrary tilt and curvature. Essential elements include debiasing and flatfielding of the raw CCD image, removal of scattered light background, either nonoptimal or optimal extraction of data, and wavelength calibration and continuum normalization of the extracted orders. A growing set of support routines permits examination of the frame being processed to provide continuing checks on the statistical properties of the data and on the accuracy of the extraction. We will display some sample reductions and discuss the algorithms used. The inherent simplicity and user-friendliness of the IDL interface make this package a useful tool for spectroscopists. We will provide an email distribution list for those interested in receiving the package, and further documentation will be distributed at the meeting.

VizieR Online Data Catalog: Line list for red giants in open clusters (Reddy+, 2015)

NASA Astrophysics Data System (ADS)

Reddy, A. B. S.; Giridhar, S.; Lambert, D. L.

2017-11-01

Observations were carried out during observing runs in 2011 May and November, 2012 November and 2013 March using the Robert G. Tull echelle spectrograph (Tull et al. 1995PASP..107..251T) at the coude focus of the 2.7m Harlan J. Smith telescope located at the McDonald Observatory. On all occasions we employed a 2048x2048 24μm pixel, backside-illuminated, anti-reflection coated CCD as a detector and the 52.67 grooves/mm echelle grating with exposures centred at 5060Å. (2 data files).

VizieR Online Data Catalog: WIYN open cluster study. LIX. RVs of NGC 6791 (Tofflemire+, 2014)

NASA Astrophysics Data System (ADS)

Tofflemire, B. M.; Gosnell, N. M.; Mathieu, R. D.; Platais, I.

2014-11-01

Our observations utilize the Hydra Multi-Object Spectrograph (MOS) on the WIYN 3.5m telescope. We use 3.1'' diameter fibers along with the bench spectrograph echelle grating, resulting in a spectral resolution of ~20000 (15km/s). See Geller et al. 2008 (cat. J/AJ/135/2264; Paper XXXII) for full details about our observing and data reduction procedures. Variations in our methods from previous WIYN Open Cluster Study (WOCS) radial velocity papers are given in Section 3. (3 data files).

On the design of the PEPSI spectropolarimeter for the LBT

NASA Astrophysics Data System (ADS)

Ilyin, I.; Strassmeier, K. G.; Woche, M.; Dionies, F.; Di Varano, I.

2011-10-01

We present the design concept of the spectropolarimeter for the high-resolution echelle spectrograph PEPSI to be installed at the 2×8.4 m Large Binocular Telescope (LBT) in Arizona. We discuss the optical key elements, the principles of operations of the instrument and its instrumental polarization effects.

VizieR Online Data Catalog: 6 cold-gas-bearing debris-disc stars spectra (Rebollido+, 2018)

NASA Astrophysics Data System (ADS)

Rebollido, I.; Eiroa, C.; Montesinos, B.; Maldonado, J.; Villaver, E.; Absi, O.; Bayo, A.; Canovas, H.; Carmona, A.; Chen, Ch.; Ertel, S.; Garufi, A.; Henning, T.; Iglesias, D. P.; Launhardt, R.; Liseau, R.; Meeus, G.; Moor, A.; Mora, A.; Olofsson, J.; Rauw, G.; Riviere-Marichalar, P.

2018-02-01

Spectra obtained with Mercator (La Palma, Spain), NOT (La Palma, Spain) and Tigre (La Luz, Mexico) echelle spectrographs. Observation dates range from September 2015 to July 2016. They were reduced using instrument pipelines. Barycentric correction has been applied to all spectra. (2 data files).

The optical design of the G-CLEF Spectrograph: the first light instrument for the GMT

NASA Astrophysics Data System (ADS)

Ben-Ami, Sagi; Epps, Harland; Evans, Ian; Mueller, Mark; Podgorski, William; Szentgyorgyi, Andrew

2016-08-01

The GMT-Consortium Large Earth Finder (G-CLEF), the first major light instrument for the GMT, is a fiber-fed, high-resolution echelle spectrograph. In the following paper, we present the optical design of G-CLEF. We emphasize the unique solutions derived for the spectrograph fiber-feed: the Mangin mirror that corrects the cylindrical field curvature, the implementation of VPH grisms as cross dispersers, and our novel solution for a multi-colored exposure meter. We describe the spectrograph blue and red cameras comprised of 7 and 8 elements respectively, with one aspheric surface in each camera, and present the expected echellogram imaged on the instrument focal planes. Finally, we present ghost analysis and mitigation strategy that takes into account both single reflection and double reflection back scattering from various elements in the optical train.

VizieR Online Data Catalog: FGK dwarfs atmospheric parameters (Ryabchikova+, 2016)

NASA Astrophysics Data System (ADS)

Ryabchikova, T.; Piskunov, N.; Pakhomov, Y.; Tsymbal, V.; Titarenko, A.; Sitnova, T.; Alexeeva, S.; Fossati, L.; Mashonkina, L.

2016-08-01

For the spectroscopic analysis, we choose the 13 MS stars including the Sun (Table 1) in the 4900-6600K temperature range and with metallicity between [Fe/H]=-1.5 and +0.3dex. All the stars, except HD 149026, have, at least, one interferometric determination of radius and effective temperature. Spectra of the programme stars were obtained with different spectrographs. Most data were extracted from the following archives: the UVES/VLT and HARPS/3.6m spectrographs at ESO,2 the ELODIE/1.93-m spectrograph3 at the Observatoire de Haute Provence, and the ESPaDONs spectrograph at the Canada-France-Hawaii Telescope (CFHT). Spectra of beta Vir and HD 103095 were obtained with the FOCES spectrograph at 2.2-m telescope of the Calar Alto Observatory. One of the spectra of 61 Vir was obtained with the Hamilton Echelle Spectrograph attached to the Shane 3-m telescope of the Lick Observatory. Spectra of few stars, including that of the Sun reflected from Ganymede, were obtained with the HiReS/Keck spectrograph. (3 data files).

Elemental abundance analyses with Complejo Astronomico. EL Leoncito REOSC echelle spectrograms. I. κ Cancri, HR 7245, and ξ Octantis

NASA Astrophysics Data System (ADS)

Pintado, O. I.; Adelman, S. J.

1996-08-01

Elemental abundances are derived for three sharp-lined stars κ Cnc, HR 7245, and ξ Oct using REOSC echelle spectrograms obtained at CASLEO. Comparisons are made with published equivalent widths. The derived abundances for κ Cnc and ξ Oct are slightly larger than those obtained with other high dispersion spectrographs. HR 7245 exhibits a pattern of abundance anomalies similar to other Mercury-Manganese stars. The spectra of the two HgMn stars in the λλ4640-5100 region exhibit an interesting and useful variety of lines which can be used to supplement analyses of the photographic region.

Keck and VLT Observations of Super-Damped Lyman-Alpha Absorbers at z 2- 2.5: Constraints on Chemical Compositions and Physical Conditions

NASA Astrophysics Data System (ADS)

Kulkarni, Varsha P.; Som, Debopam; Morrison, Sean; Péroux, Celine; Quiret, Samuel; York, Donald G.

2015-12-01

We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Lyα quasar absorbers with H i column densities log NH i ≥ 21.7 at redshifts 2 ≲ z ≲ 2.5. All three absorbers show similar metallicities (˜-1.3 to -1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other damped Lyα a absorbers (DLAs) to examine trends between NH i, metallicity, and dust depletion. A larger fraction of the super-DLAs lie close to or above the line [X/H] = 20.59 - log NH i in the metallicity versus NH i plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230-0334 and Q0743+1421 do not cover H2 absorption lines. For Q1418+0718, some H2 lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log NH i < 21.7, we confirm strong correlation between metallicity and Fe depletion, and find a correlation between metallicity and Si depletion. For super-DLAs, these correlations are weaker or absent. The absorbers toward Q0230-0334 and Q1418+0718 show potential detections of weak Lyα emission, implying star formation rates of ˜1.6 and ˜0.7 M⊙ yr-1, respectively (ignoring dust extinction). Upper limits on the electron densities from C ii*/C ii or Si ii*/Si ii are low, but are higher than the median values in less gas-rich DLAs. Finally, systems with log NH i > 21.7 may have somewhat narrower velocity dispersions Δv90 than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas. Includes observations collected during program ESO 93.A-0422 at the European Southern Observatory (ESO) Very Large Telescope (VLT) with the Ultraviolet-Visual Echelle Spectrograph (UVES) on the 8.2 m telescopes operated at the Paranal Observatory, Chile. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

Follow-up spectroscopy and photometry of Dwarf Nova V392 Per

NASA Astrophysics Data System (ADS)

Mugrauer, M.; Gilbert, H.; Hoffmann, S.

2018-05-01

On 2018 May 1th 20 UT (JD=2458240.333) we took spectroscopic data of the dwarf nova V392 Per (ATel #11588; ATel #11601; ATel #11605) with the echelle spectrograph FLECHAS (Mugrauer et al. 2014, AN 335, 417) at the 90cm telescope of the University Observatory Jena.

Calibration Efforts and Unique Capabilities of the HST Space Telescope Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Monroe, TalaWanda R.; Proffitt, Charles R.; Welty, Daniel; Branton, Doug; Carlberg, Joleen K.; debes, John Henry; Lockwood, Sean; Riley, Allyssa; Sohn, Sangmo Tony; Sonnentrucker, Paule G.; Walborn, Nolan R.; Jedrzejewski, Robert I.

2018-01-01

The Space Telescope Imaging Spectrograph (STIS) continues to offer the astronomy community the ability to carry out innovative UV and optical spectroscopic and imaging studies, two decades after its deployment on the Hubble Space Telescope (HST). Most notably, STIS provides spectroscopy in the FUV and NUV, including high spectral resolution echelle modes, imaging in the FUV, optical spectroscopy, and coronagraphic capabilities. Additionally, spatial scanning on the CCD with the long-slits is now possible to enable very high S/N spectroscopic observations without saturation while mitigating telluric and fringing concerns in the far red and near-IR. This new mode may especially benefit the diffuse interstellar bands and exoplanet transiting communities. We present recent calibration efforts for the instrument, including work to optimize the calibration of the echelle spectroscopic modes by improving the flux agreement of overlapping spectral orders affected by changes in the grating blaze function since HST Servicing Mission 4. We also discuss considerations to maintain the wavelength precision of the spectroscopic modes, and the current capabilities of CCD spectroscopic spatial trails.

Design study of the PEPSI polarimeter for the LBT

NASA Astrophysics Data System (ADS)

Hofmann, A.; Strassmeier, K. G.; Woche, M.

2002-07-01

We present the conceptual design of the two polarimetric channels of the PEPSI spectropolarimeter for the Large Binocular Telescope (LBT). The two direct Gregorian f/15 focii of the LBT will take up two identical but independent full-Stokes IQUV polarimeters that themselves fiberfeed a high-resolution Echelle spectrograph (see the accompanying paper by Zerbi et al.). The polarizing units will be based on super-achromatic Fresnel-rhomb retarders and Foster prisms. A total of four fibers are foreseen to simultaneously direct two ordinary and two extraordinary light beams to the Echelle spectrograph. Both polarimetric units are layed out in a modular design, each one optimized to the polarization state in which it is used. A number of observing modes can be chosen that are optimized to the type of polarization that is expected from the target, e.g. circularly and linearly polarized light simultaneously, or linearly polarized light in both polarimeters, or integral light from one and polarized light from the other telescope, a.s.o.. Calibration would be provided for each polarimeter separately.

Instruments at the Lowell Observatory Discovery Channel Telescope (DCT)

NASA Astrophysics Data System (ADS)

Jacoby, George H.; Bida, Thomas A.; Fischer, Debra; Horch, Elliott; Kutyrev, Alexander; Mace, Gregory N.; Massey, Philip; Roe, Henry G.; Prato, Lisa A.

2017-01-01

The Lowell Observatory Discovery Channel Telescope (DCT) has been in full science operation for 2 years (2015 and 2016). Five instruments have been commissioned during that period, and two additional instruments are planned for 2017. These include:+ Large Monolithic Imager (LMI) - a CCD imager (12.6 arcmin FoV)+ DeVeny - a general purpose optical spectrograph (2 arcmin slit length, 10 grating choices)+ NIHTS - a low resolution (R=160) YJHK spectrograph (1.3 arcmin slit)+ DSSI - a two-channel optical speckle imager (5 arcsec FoV)+ IGRINS - a high resolution (45,000) HK spectrograph, on loan from the University of Texas.In the upcoming year, instruments will be delivered from the University of Maryland (RIMAS - a YJHK imager/spectrograph) and from Yale University (EXPRES - a very high resolution stabilized optical echelle for PRV).Each of these instruments will be described, along with their primary science goals.

Current Calibration Efforts and Performance of the HST Space Telescope Imaging Spectrograph: Echelle Flux Calibration, the BAR5 Occulter, and Lamp Lifetimes

NASA Astrophysics Data System (ADS)

Monroe, TalaWanda R.; Aloisi, Alessandra; Debes, John H.; Jedrzejewski, Robert I.; Lockwood, Sean A.; Peeples, Molly S.; Proffitt, Charles R.; Riley, Allyssa; Walborn, Nolan R.

2016-06-01

The variety of operating modes of the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) continues to allow STIS users to obtain unique, high quality observations and cutting-edge results 19 years after its installation on HST. STIS is currently the only instrument available to the astronomy community that allows high spectral and spatial resolution spectroscopy in the FUV and NUV, including echelle modes. STIS also supports solar-blind imaging in the FUV. In the optical, STIS provides long-slit, first-order spectra that take advantage of HST's superb spatial resolution, as well as several unique unfiltered coronagraphic modes, which continue to benefit the exoplanet and debris-disk communities. The STIS instrument team monitors the instrument’s health and performance over time to characterize the effects of radiation damage and continued use of the detectors and optical elements. Additionally, the STIS team continues to improve the quality of data products for the user community. We present updates on efforts to improve the echelle flux calibration of overlapping spectral orders due to changes in the grating blaze function since HST Servicing Mission 4, and efforts to push the contrast limit and smallest inner working angle attainable with the coronagraphic BAR5 occulter. We also provide updates on the performance of the STIS calibration lamps, including work to maintain the accuracy of the wavelength calibration for all modes.

VizieR Online Data Catalog: Radial velocities of HD 133131A and HD 133131B (Teske+, 2016)

NASA Astrophysics Data System (ADS)

Teske, J. K.; Shectman, S. A.; Vogt, S. S.; Diaz, M.; Butler, R. P.; Crane, J. D.; Thompson, I. B.; Arriagada, P.

2017-05-01

The radial velocity observations of HD133131A and B are part of the large Magellan Planet Search Program, which began in 2002 and is surveying a sample of ~500 of the nearest stars (<100pc). The survey was started with observations from the Magellan Inamori Kyocera Echelle (MIKE) echelle spectrograph, mounted for a limited time on the Magellan I (Baade), but mostly on Magellan II (Clay), 6.5m telescopes at Las Campanas Observatory. In 2010, the survey switched to using the Carnegie Planet Finder Spectrograph (PFS), a temperature-controlled high-resolution echelle spectrograph built for precision radial velocity observations, on Magellan II. Only HD133131A observations from MIKE are included here. Using a 0.35*5'' slit, MIKE provides spectra with R~70000 in the blue and ~50000 in the red and covers 3900-6200Å. Only the red MIKE orders are used for radial velocity determination, while the blue orders provide coverage of the CaIIH and K lines for monitoring stellar activity. The MIKE observations of HD133131A span 2003 June to 2009 July, with total exposure times ranging from 150 to 600s, depending on observing conditions. Both HD133131A and B were observed with PFS, the former observations ranging from 2010 February to 2015 September, and the latter from 2010 August to 2015 September. PFS has a more limited wavelength range than MIKE (3880-6680Å), but still covers the entire iodine wavelength region, CaIIH and K, and Hα. We use a 0.5*2.5'' slit for target observations, providing R~80000 in the iodine region. The total exposure times for the A component range from 285 to 720s, and for the B component range from 282 to 800s. (6 data files).

VizieR Online Data Catalog: Reflectance spectra of 12 Trojans and Hildas (Marsset+, 2014)

NASA Astrophysics Data System (ADS)

Marsset, M.; Vernazza, P.; Gourgeot, F.; Dumas, C.; Birlan, M.; Lamy, P.; Binzel, R. P.

2014-07-01

We present 17 reflectance spectra of 12 high albedo (pv>0.14) Trojans (8 objects) and Hildas (4 objects) obtained with the ESO/VLT Echelle spectrograph X-SHOOTER in the 0.3-2.2um spectral range (14 spectra) and with the NASA/IRTF spectrograph SpeX in the 0.8-2.5um spectral range (3 spectra). X-SHOOTER spectra were normalized to unity at 0.55um and SpeX spectra were normalized to unity at 2.2um . The spectra presented in this work were collected between April and December 2013. (18 data files).

PEPSI, the High-Resolution Optical-IR Spectrograph for the LBT

NASA Astrophysics Data System (ADS)

Andersen, Michael; Strassmeier, Klaus; Hoffman, Axel; Woche, Manfred; Spano, Paolo

PEPSI is a high resolution fibre feed optical-IR polarimetric echelle spectrograph for the Large Binocular Telescope (LBT). PEPSI utilizes the two 8.4m LBT apertures to simultaneously record four polarization states at a resolution of 120.000. The extension of the coverage towards the IR is mainly motivated by the larger Zeeman splitting of IR lines, which would allow to study weaker/fainter magnetic structures on stars. The two optical arms, which also have an integral light mode with R up to 300.000, are under construction, while the IR arm is being designed.

Observations of Infrared Molecular Lines Toward the Massive Protostar GL 2591

NASA Astrophysics Data System (ADS)

Knez, C.; Boonman, A. M. S.; Lacy, J. H.; Evans, N. J., II; Richter, M. J.

2001-12-01

Using TEXES (Texas Echelon Cross Echelle Spectrograph) at the NASA Infrared Telescope Facility, we have observed rovibrational transitions of C2H2 and HCN near 13 microns in absorption toward the deeply embedded, massive protostar, GL 2591. GL 2591 is obscured by about 70 magnitudes of visual extinction; however, it is one of the brightest mid-infrared sources. The following lines were observed: C2H2 R(5), R(6), R(12), and R(13) and HCN R(10) and R(16). With a spectral resolution of ~ 3 km/s, all lines are resolved. We show the line profiles and compare the spectra to previous results from Carr et al. (1995), Lahuis & van Dishoeck (2000) and Boonman et al. (2001). Observations with TEXES were supported by the Texas Advanced Research Program.

EXPRES: a next generation RV spectrograph in the search for earth-like worlds

NASA Astrophysics Data System (ADS)

Jurgenson, C.; Fischer, D.; McCracken, T.; Sawyer, D.; Szymkowiak, A.; Davis, A.; Muller, G.; Santoro, F.

2016-08-01

The EXtreme PREcision Spectrograph (EXPRES) is an optical fiber fed echelle instrument being designed and built at the Yale Exoplanet Laboratory to be installed on the 4.3-meter Discovery Channel Telescope operated by Lowell Observatory. The primary science driver for EXPRES is to detect Earth-like worlds around Sun-like stars. With this in mind, we are designing the spectrograph to have an instrumental precision of 15 cm/s so that the on-sky measurement precision (that includes modeling for RV noise from the star) can reach to better than 30 cm/s. This goal places challenging requirements on every aspect of the instrument development, including optomechanical design, environmental control, image stabilization, wavelength calibration, and data analysis. In this paper we describe our error budget, and instrument optomechanical design.

VizieR Online Data Catalog: New FeI level energies from stellar spectra. II. (Peterson+, 2017)

NASA Astrophysics Data System (ADS)

Peterson, R. C.; Kurucz, R. L.; Ayres, T. R.

2017-06-01

All of the new space-based UV spectra were obtained at a two-pixel resolution of 110000 with the E230H echelle grating of the Space Telescope Imaging Spectrograph (STIS) on HST, under program GO-14161 (R. Peterson, PI). See section 2 for further explanations. (2 data files).

VizieR Online Data Catalog: Chemical compositions of 11 RR Lyrae (For+, 2011)

NASA Astrophysics Data System (ADS)

For, B.-Q.; Sneden, C.; Preston, G. W.

2012-01-01

The spectroscopic data were obtained with the du Pont 2.5m telescope at the Las Campanas Observatory (LCO), using a cross-dispersed echelle spectrograph with a total wavelength coverage of 3500-9000Å. See Section 3 of For et al. 2011, Cat. J/ApJS/194/38, for details of data reduction. (4 data files).

VizieR Online Data Catalog: V-band photometry and RVs of V482 Persei system (Torres+, 2017)

NASA Astrophysics Data System (ADS)

Torres, G.; Lacy, C. H. S.; Fekel, F. C.; Wolf, M.; Muterspaugh, M. W.

2018-05-01

Differential photometry of V482 Per was obtained by measuring images collected with two different robotic telescopes: the URSA WebScope at the University of Arkansas at Fayetteville, AR, and the NFO WebScope near Silver City, NM. All observations were made through a Bessel V filter. Observations were made between 2001 December and 2016 January, and are presented in Tables 1 and 2. V482 Per was monitored spectroscopically with two different instruments. We observed it between 2009 November and 2017 February at the Harvard-Smithsonian Center for Astrophysics (CfA) with the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5m Tillinghast reflector at the Fred L. Whipple Observatory (Mount Hopkins, AZ). The wavelength coverage is approximately 3900-9100Å, with a resolving power R~44000. From 2011 November through 2017 April, we additionally acquired 37 useful spectra of V482 Per with the Tennessee State University 2m Automatic Spectroscopic Telescope (AST) and a fiber-fed echelle spectrograph at the Fairborn Observatory in southeast Arizona. We used only the wavelength region from 4920 to 7100Å, with a resolving power R~15000 at 6000Å. (6 data files).

Using laser-induced breakdown spectroscopy on vacuum alloys-production process for elements concentration analysis

NASA Astrophysics Data System (ADS)

Zhao, Tianzhuo; Fan, Zhongwei; Lian, Fuqiang; Liu, Yang; Lin, Weiran; Mo, Zeqiang; Nie, Shuzhen; Wang, Pu; Xiao, Hong; Li, Xin; Zhong, Qixiu; Zhang, Hongbo

2017-11-01

Laser-induced breakdown spectroscopy (LIBS) utilizing an echelle spectrograph-ICCD system is employed for on-line analysis of elements concentration in a vacuum induction melting workshop. Active temperature stabilization of echelle spectrometer is implemented specially for industrial environment applications. The measurement precision is further improved by monitoring laser parameters, such as pulse energy, spatial and temporal profiles, in real time, and post-selecting laser pulses with specific pulse energies. Experimental results show that major components of nickel-based alloys are stable, and can be well detected. By using internal standard method, calibration curves for chromium and aluminum are obtained for quantitative determination, with determination coefficient (relative standard deviation) to be 0.9559 (< 2.2%) and 0.9723 (< 2.8%), respectively.

VizieR Online Data Catalog: Abundance ratio for 5 local stellar associations (Reddy+, 2015)

NASA Astrophysics Data System (ADS)

Reddy, A. B. S.; Lambert, D. L.

2018-01-01

In this paper, we have performed a homogeneous and a comprehensive abundance analysis using high-resolution spectroscopy. High-resolution and high signal-to-noise (S/N) spectra of the program stars were obtained during the nights of 2015 February 10-11 with the Robert G. Tull coude cross-dispersed echelle spectrograph (Tull et al. 1995PASP..107..251T) of the 2.7 m Harlan J. Smith reflector at the McDonald Observatory. We employed a Tektronix 2048x2048 24 μm pixel, backside illuminated and anti-reflection coated CCD as a detector and an R2 echelle grating with 52.67 grooves/mm with exposures centred at 5060 Å. (7 data files).

VizieR Online Data Catalog: Abundances of metal-poor star HD 94028 (Roederer+, 2016)

NASA Astrophysics Data System (ADS)

Roederer, I. U.; Karakas, A. I.; Pignatari, M.; Herwig, F.

2016-06-01

We use two NUV spectroscopic data sets of HD 94028 available in the Mikulski Archive for Space Telescopes. These observations were made using STIS on board the HST. One spectrum (data sets O5CN01-03, GO-8197, PI. Duncan) has very high spectral resolution (R~110000). This spectrum covers ~1885-2147Å with signal-to-noise ratios (S/N)35/1 per pixel near 2140Å. The other spectrum (data sets O56D06-07, GO-7402, PI. Peterson) has high spectral resolution (R~30000). This spectrum covers 2280-3117Å with S/N ranging from ~20 near 2300Å to ~40 near 3100Å. Roederer et al. (2014, J/AJ/147/136) derived abundances from an optical spectrum of HD 94028 taken using the Robert G. Tull Coude Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, Texas. We rederive abundances from this spectrum. We also use an optical spectrum taken with the Ultraviolet and Visual Echelle Spectrograph (UVES) on the Very Large Telescope (VLT) Kueyen at Cerro Paranal, Chile. We obtained this spectrum from the ESO Science Archive. This spectrum covers 3050-3860Å at R~37000 with S/N ranging from ~40 near 3200Å to ~130 near 3800Å. (3 data files).

Integration of a thermo-structural analysis with an optical model for PEPSI polarimeter

NASA Astrophysics Data System (ADS)

Di Varano, Igor; Strassmeier, Klaus G.; Ilyin, Ilya; Woche, Manfred; Kaercher, Hans J.

2011-09-01

The two spectropolarimeters for PEPSI (Potsdam Echelle Polarimetric and Spectroscopic Instrument) have been de¬signed in order to reconstruct the full Stokes vector measuring linear and circular polarization simultaneously with a re¬solving power of 120,000. The polarimeters will be attached to the Gregorian focus of the so far largest LBT 2x8.4m telescope and will feed together with permanent focus stations the spectrograph via 44m long fibers connection. The spectrograph will be located in a pressure-temperature controlled chamber within the telescope pier. We present hereafter the last results from combined structural and CFD analyses in order to fulfill the optical requirements.

Development of television tubes for the large space telescope

NASA Technical Reports Server (NTRS)

Lowrance, J. L.; Zucchino, P.

1971-01-01

Princeton Observatory has been working for several years under NASA sponsorship to develop television type sensors to use in place of photographic film for space astronomy. The performance of an SEC-vidicon with a 25 mm x 25 mm active area, MgF2 window, and bi-alkali photocathode is discussed. Results from ground based use on the Coude spectrograph of the 200-inch Hale telescope are included. The intended use of this tube in an echelle spectrograph sounding rocket payload and on Stratoscope 2 for direct high resolution imagery is also discussed. The paper also discusses the large space telescope image sensor requirements and the development of a larger television tube for this mission.

Thirty Years, One Million Spectra: Public Access to the SAO Spectral Archives

NASA Astrophysics Data System (ADS)

Mink, J.; Moran, S.

2015-09-01

Over the last 30 years, the SAO Telescope Data Center has reduced and archived over 1,000,000 spectra, consisting of 287,000 spectra from five high dispersion Echelle spectrographs and 717,000 spectra from four low dispersion spectrographs, across three telescopes. 151,000 spectra from six instruments are currently online and publicly available, covering many interesting objects in the northern sky, including most of the galaxies in the Updated Zwicky Catalog which are reachable through NED or Simbad. A majority of the high dispersion spectra will soon be made public, as will more data from the MMT multi-fiber spectrographs. Many objects in the archive have multiple spectra over time, which make them a valuable resource for archival time-domain studies. We are now developing a system to make all of the public spectra more easily searchable and viewable through the Virtual Observatory.

Process analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy.

PubMed

Fink, Herbert; Panne, Ulrich; Niessner, Reinhard

2002-09-01

An experimental setup for direct elemental analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy (LIPS, or laser-induced breakdown spectroscopy, LIBS) was realized. The combination of a echelle spectrograph, featuring a high resolution with a broad spectral coverage, with multivariate methods, such as PLS, PCR, and variable subset selection via a genetic algorithm, resulted in considerable improvements in selectivity and sensitivity for this complex matrix. With a normalization to carbon as internal standard, the limits of detection were in the ppm range. A preliminary pattern recognition study points to the possibility of polymer recognition via the line-rich echelle spectra. Several experiments at an extruder within a recycling plant demonstrated successfully the capability of LIPS for different kinds of routine on-line process analysis.

AIRES: An Airborne Infra-Red Echelle Spectrometer for SOFIA

NASA Technical Reports Server (NTRS)

Dotson, Jessie J.; Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Telesco, Charles M.; Pina, Robert K.; Wolf, Juergen; Young, Erick T.

1999-01-01

SOFIA will enable astronomical observations with unprecedented angular resolution at infrared wavelengths obscured from the ground. To help open this new chapter in the exploration of the infrared universe, we are building AIRES, an Airborne Infra-Red Echelle Spectrometer. AIRES will be operated as a first generation, general purpose facility instrument by USRA, NASA's prime contractor for SOFIA. AIRES is a long slit spectrograph operating from 17 - 210 microns. In high resolution mode the spectral resolving power is approx. 10(exp 6) microns/A or approx. 10(exp 4) at 100 microns. Unfortunately, since the conference, a low resolution mode with resolving power about 100 times lower has been deleted due to budgetary constraints. AIRES includes a slit viewing camera which operates in broad bands at 18 and 25 microns.

VizieR Online Data Catalog: Detailed abundances of KOI stars with planets. I. (Schuler+, 2015)

NASA Astrophysics Data System (ADS)

Schuler, S. C.; Vaz, Z. A.; Katime Santrich, O. J.; Cunha, K.; Smith, V. V.; King, J. R.; Teske, J. K.; Ghezzi, L.; Howell, S. B.; Isaacson, H.

2016-03-01

We have analyzed high-resolution, high-signal-to-noise ratio (S/N) spectra of seven stars, each of which has at least one confirmed small planet discovered by Kepler. The spectra of these stars were obtained as part of the Kepler Follow-up Observing Program (KFOP). The 10m Keck I telescope and High Resolution Echelle Spectrometer (HIRES) are being utilized for precise RV measurements of high-priority KOIs. The KFOP spectra are characterized by a spectral resolution of R=50000 and span 3650-7950Å with incomplete coverage in the reddest orders. Additional observations of Kepler-21 were made independently with Keck/HIRES and the 4m Mayall telescope and echelle spectrograph at Kitt Peak National Observatory (KPNO) in UT 2011. (4 data files).

High Resolution Spectrograph for the Hobby-Eberly Telescope

NASA Astrophysics Data System (ADS)

Tull, R. G.; MacQueen, P. J.; Good, J.; Epps, H. W.; HET HRS Team

1998-12-01

A fiber fed high-resolution spectrograph (HRS) is under construction for the Hobby-Eberly Telescope (HET). The primary resolving power originally specified, from astrophysical considerations, was R = 60,000 with a fiber of diameter at least 1 arc-second, with full spectral coverage limited only by the combined band-pass of the HET, the optical fiber, and the image detector. This was achieved in the final design with a high blaze angle R-4 echelle mosaic, white pupil design, image slicing, and a large area CCD mosaic illuminated by an eight element refractive camera. Two back-to-back, user selectable first-order diffraction gratings are employed for cross dispersion, to separate echelle spectral orders; the entire spectral range (420 - 1,000 nm) can be covered in as few as two exposures. Critical issues addressed in the design are cross dispersion and order spacing, sky subtraction, echelle and CCD selection, fiber optic feed and scrambling, and image or pupil slicing. In the final design meeting the requirements we exploited the large-area 4096 square CCD, image slicing, and the optical performance of the white-pupil design to acquire a range of 30,000 < R < 120,000 with fibers of diameter 2 and 3 arc-seconds, without sacrificing full spectral coverage. Design details will be presented. Limiting magnitude is projected to be about V = 19 (for S/N = 10) at the nominal R = 60,000 resolving power. The poster display will outline performance characteristics expected in relation to projected astrophysical research capabilities outlined by Sneden et al., in this conference. HRS is supported by generous grants from NSF, NASA, the State of Texas, and private philanthropy, with matching funds granted by the University of Texas and by McDonald Observatory.

The opto-mechanical design of the GMT-Consortium Large Earth Finder (G-CLEF)

NASA Astrophysics Data System (ADS)

Mueller, Mark; Szentgyorgyi, Andrew; Baldwin, Daniel; Bean, Jacob; Ben-Ami, Sagi; Brennan, Patricia; Budynkiewicz, J.; Chun, Moo-Yung; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Foster, Jeff; Frebel, Anna; Gauron, Thomas; Glenday, Alex; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jordan, Andreas; Kim, Jihun; Kim, Kang-Min; Mendes de Oliveira, Claudia; Lopez-Morales, Mercedes; McCracken, Kenneth; McMuldroch, Stuart; Miller, Joseph; Oh, Jae Sok; Onyuksel, Cem; Ordway, Mark; Park, Chan; Park, Sung-Joon; Paxson, Charles; Phillips, David; Plummer, David; Podgorski, William; Seifahrt, Andreas; Steiner, Joao; Uomoto, Alan; Walsworth, Ronald; Yu, Young-Sam

2016-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, optical echelle spectrograph selected as the first light instrument for the Giant Magellan Telescope (GMT) now under construction at the Las Campanas Observatory in Chile. G-CLEF has been designed to be a general-purpose echelle spectrograph with precision radial velocity (PRV) capability for exoplanet detection. The radial velocity (RV) precision goal of G-CLEF is 10 cm/sec, necessary for detection of Earth-sized exoplanets. This goal imposes challenging stability requirements on the optical mounts and the overall spectrograph support structures especially when considering the instrument's operational environment. The accuracy of G-CLEF's PRV measurements will be influenced by minute changes in temperature and ambient air pressure as well as vibrations and micro gravity-vector variations caused by normal telescope slewing. For these reasons we have chosen to enclose G-CLEF's spectrograph in a well-insulated, vibration isolated vacuum chamber in a gravity invariant location on GMT's azimuth platform. Additional design constraints posed by the GMT telescope include: a limited space envelope, a thermal emission ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology and budget are also significant design drivers. All of the above considerations must be managed while ensuring performance requirements are achieved. In this paper, we discuss the design of G-CLEF's optical mounts and support structures including the choice of a low coefficient of thermal expansion (CTE) carbon-fiber optical bench to minimize the system's sensitivity to thermal soaks and gradients. We discuss design choices made to the vacuum chamber geared towards minimize the influence of daily ambient pressure variations on image motion during observation. We discuss the design of G-CLEF's insulated enclosure and thermal control systems which will maintain the spectrograph at milli-Kelvin level stability while simultaneously limiting thermal emissions into the telescope dome. Also discussed are micro gravity-vector variations caused by normal telescope slewing, their uncorrected influence on image motion, and how they are dealt with in the design. Finally, we discuss G-CLEF's front-end assembly and fiber-feed system as well as other interface challenges presented by the telescope, enclosure and neighboring instrumentation.

The opto-mechanical design of the GMT-consortium large earth finder (G-CLEF)

NASA Astrophysics Data System (ADS)

Mueller, Mark; Baldwin, Daniel; Bean, Jacob; Bergner, Henry; Bigelow, Bruce; Chun, Moo-Young; Crane, Jeffrey; Foster, Jeff; Fżrész, Gabor; Gauron, Thomas; Guzman, Dani; Hertz, Edward; Jordán, Andrés.; Kim, Kang-Min; McCracken, Kenneth; Norton, Timothy; Ordway, Mark; Park, Chan; Park, Sang; Podgorski, William A.; Szentgyorgyi, Andrew; Uomoto, Alan; Yuk, In-Soo

2014-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) is a fiber fed, optical echelle spectrograph that has been selected as a first light instrument for the Giant Magellan Telescope (GMT) currently under construction at the Las Campanas Observatory in Chile's Atacama desert region. We designed G-CLEF as a general-purpose echelle spectrograph with precision radial velocity (PRV) capability used for exoplanet detection. The radial velocity (RV) precision goal of GCLEF is 10 cm/sec, necessary for detection of Earth-sized planets orbiting stars like our Sun in the habitable zone. This goal imposes challenging stability requirements on the optical mounts and the overall spectrograph support structures. Stability in instruments of this type is typically affected by changes in temperature, orientation, and air pressure as well as vibrations caused by telescope tracking. For these reasons, we have chosen to enclose G-CLEF's spectrograph in a thermally insulated, vibration isolated vacuum chamber and place it at a gravity invariant location on GMT's azimuth platform. Additional design constraints posed by the GMT telescope include: a limited space envelope, a thermal emission ceiling, and a maximum weight allowance. Other factors, such as manufacturability, serviceability, available technology and budget are also significant design drivers. All of the previously listed considerations must be managed while ensuring that performance requirements are achieved. In this paper, we discuss the design of G-CLEF's optical mounts and support structures including technical choices made to minimize the system's sensitivity to thermal gradients. A more general treatment of the properties of G-CLEF can be found elsewhere in these proceedings1. We discuss the design of the vacuum chamber which houses the irregularly shaped optical bench and optics while conforming to a challenging space envelope on GMT's azimuth platform. We also discuss the design of G-CLEF's insulated enclosure and thermal control systems which maintain the spectrograph at milli-Kelvin level stability while simultaneously limiting the maximum thermal emission into the telescope dome environment. Finally, we discuss G-CLEF's front-end assembly and fiber-feed system as well as other interface challenges presented by the telescope, enclosure and neighboring instrumentation.

HPF: The Habitable Zone Planet Finder at the Hobby-Eberly Telescope

NASA Astrophysics Data System (ADS)

Wright, Jason T.; Mahadevan, Suvrath; Hearty, Fred; Monson, Andy; Stefansson, Gudmundur; Ramsey, Larry; Ninan, Joe; Bender, Chad; Kaplan, Kyle; Roy, Arpita; Terrien, Ryan; Robertson, Paul; Halverson, Sam; Schwab, Christian; Kanodia, Shubham

2018-01-01

The Habitable Zone Planet Finder (HPF) is an ultra-stable NIR (ZYJ) high resolution echelle spectrograph on the 10-m Hobby-Eberly Telescope capable of 1-3 m/s Doppler velocimetry on nearby late M dwarfs (M4-M9). This precision is sufficient to detect terrestrial planets in the Habitable Zones of these relatively unexplored stars. Here we present its capabilities and early commissioning results.

VizieR Online Data Catalog: The G+M eclipsing binary V530 Orionis photometry (Torres+, 2014)

NASA Astrophysics Data System (ADS)

Torres, G.; Lacy, C. H. S.; Pavlovski, K.; Feiden, G. A.; Sabby, J. A.; Bruntt, H.; Clausen, J. V.

2017-08-01

V530 Ori was monitored spectroscopically with three different instruments over a period of more than 17 yr. Observations began at the Harvard-Smithsonian Center for Astrophysics (CfA) in 1996 June with a Cassegrain-mounted echelle spectrograph ("Digital Speedometer", DS; Latham 1992ASPC...32..110L) attached to the 1.5 m Tillinghast reflector at the F. L. Whipple Observatory (Mount Hopkins, AZ). We gathered a further 30 spectra of V530 Ori at the Kitt Peak National Observatory (KPNO) from 1999 March to 2001 January, using the coude-feed telescope and the coude spectrometer. Finally, 41 additional observations were obtained at the CfA from 2009 November to 2014 March with the Tillinghast Reflector Echelle Spectrograph (TRES; Furesz 2008, PhD thesis , Univ. Szeged, Hungary) on the 1.5 m telescope mentioned earlier. Two sets of V-band images of V530 Ori were obtained with independent robotic telescopes operating at the University of Arkansas (URSA WebScope) and near Silver City, NM (NFO WebScope) from 2001 January to 2012 February. Differential photometric measurements of V530 Ori were also gathered with the Stromgren Automatic Telescope at ESO (La Silla, Chile), during several campaigns from 2001 January to 2006 February. (5 data files).

Multi-object medium resolution optical spectroscopy at the E-ELT

NASA Astrophysics Data System (ADS)

Spanò, Paolo; Bonifacio, Piercarlo

2008-07-01

We present the design of a compact medium resolution spectrograph (R~15,000-20,000), intended to operate on a 42m telescope in seeing-limited mode. Our design takes full advantage of some new technology optical components, like volume phase holographic (VPH) gratings. At variance with the choice of complex large echelle spectrographs, which have been the standard on 8m class telescopes, we selected an efficient VPH spectrograph with a limited beam diameter, in order to keep overall dimensions and costs low, using proven available technologies. To obtain such a resolution, we need to moderately slice the telescope image plane onto the spectrograph entrance slit (5-6 slices). Then, standard telescope AO-mode (GLAO, Ground Layer Adaptive Optics) can be used over a large field of view (~10 arcmin), without loosing efficiency. Multiplex capabilities can greatly increase the observing efficiency. A robotic pick-up mirror system can be implemented, within conventional environmental conditions (temperature, pressure, gravity, size), demanding only standard mechanical and optical tolerances. A modular approach allows us scaling multiplex capabilities on overall costs and available space.

VizieR Online Data Catalog: HeI 5876 & 10830Å EWs of solar-type stars (Andretta+, 2017)

NASA Astrophysics Data System (ADS)

Andretta, V.; Giampapa, M. S.; Covino, E.; Reiners, A.; Beeck, B.

2017-11-01

A total of 134 FEROS spectra (R=48000) of our targets (including telluric standards) were acquired on the night of UT 2011 December 6-7; spectral coverage from 3500 to 9200Å. The Fiber Extended-range Optical Spectrograph (FEROS) was mounted at the 2.2m Max-Planck Gesellschaft/European Southern Observatory (MPG/ESO) telescope at La Silla (Chile). The HeIλ10830 spectroscopic observations were carried out on the same night as the FEROS D3 observations, using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES), mounted at Unit Telescope 1 (Antu) of the VLT array at Cerro Paranal. The details of the observations is given in table 1. (3 data files).

VizieR Online Data Catalog: RAVE J203843.2-002333 high-resolution spectroscopy (Placco+, 2017)

NASA Astrophysics Data System (ADS)

Placco, V. M.; Holmbeck, E. M.; Frebel, A.; Beers, T. C.; Surman, R. A.; Ji, A. P.; Ezzeddine, R.; Points, S. D.; Kaleida, C. C.; Hansen, T. T.; Sakari, C. M.; Casey, A. R.

2018-03-01

Medium-resolution spectroscopic follow-up was carried out with the Mayall 4m Telescope at Kitt Peak National Observatory. The observations were obtained in semester 2014B, using the R-C spectrograph covering the wavelength range [3500,6000]Å (R~1600). High-resolution spectroscopic data were obtained during the 2014B and 2016A semesters, using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph on the Magellan/Clay Telescope at Las Campanas Observatory. For the 2014B run, the setup yielding a resolving power of R~38000 (blue spectral range) and R~30000 (red spectral range). For the 2016A run, the resolving power was R~66000 (coverage [~3500,9000]Å). (4 data files).

VizieR Online Data Catalog: Abundance analysis of 9 very metal-poor stars (O'Malley+, 2017)

NASA Astrophysics Data System (ADS)

O'Malley, E. M.; McWilliam, A.; Chaboyer, B.; Thompson, I.

2017-10-01

We were awarded time on HST to obtain fine guidance sensor (FGS) parallaxes of nine very metal-poor stars with the goal of extending the range of metallicities below at least [Fe/H]=-2.3dex for stars with well-determined parallaxes. High-resolution spectroscopy of the nine target stars were obtained between 2008 and 2012 using the Magellan Inamori Kyocera Echelle (MIKE) double spectrograph on the 6.5m Magellan II Clay Telescope at Las Campanas Observatory, Chile (R=48000 for the red side and R=55000 for the blue side), and the High-Resolution Echelle Spectrometer (HiRES) on the twin telescopes at the W. M. Keck Observatory (R~70500). A log of the spectroscopic observations along with the HST F606W magnitudes and parallaxes appears in Table 1. (5 data files).

Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph and FORS2 spectroscopy of the GRB 081008 afterglow

NASA Astrophysics Data System (ADS)

D'Elia, V.; Campana, S.; Covino, S.; D'Avanzo, P.; Piranomonte, S.; Tagliaferri, G.

2011-11-01

We aim at studying the gamma-ray burst (GRB), GRB 081008, environment by analysing the spectra of its optical afterglow. Ultraviolet and Visual Echelle Spectrograph/Very Large Telescope (UVES/VLT) high-resolution spectroscopy of GRB 081008 was secured ˜5 h after the Swift-BAT trigger. Our data set also comprises three VLT/FORS2 nearly simultaneous spectra of the same source. The availability of nearly simultaneous high- and low-resolution spectra for a GRB afterglow is an extremely rare event. The GRB-damped Lyman α system at z= 1.9683 shows that the interstellar medium (ISM) of the host galaxy is constituted by at least three components which contribute to the line profiles. Component I is the redmost one, and is 20 and 78 km s-1 redward components II and III, respectively. We detect several ground state and excited absorption features in components I and II. These features have been used to compute the distances between the GRB and the absorbers. Component I is found to be 52 ± 6 pc away from the GRB, while component II presents few excited transitions and its distance is 200+60- 80 pc. Component III only features a few, low-ionization and saturated lines suggesting that it is even farther from the GRB. Component I represents the closest absorber ever detected near a GRB. This (relatively) low distance can possibly be a consequence of a dense GRB environment, which prevents the GRB prompt/afterglow emission to strongly affect the ISM up to higher distances. The hydrogen column density associated with GRB 081008 is log NH/cm-2= 21.11 ± 0.10, and the metallicity of the host galaxy is in the range of [X/H] =-1.29 to -0.52. In particular, we found [Fe/H] =-1.19 ± 0.11 and [Zn/H] =-0.52 ± 0.11 with respect to solar values. This discrepancy can be explained by the presence of dust in the GRB ISM, given the opposite refractory properties of iron and zinc. By deriving the depletion pattern for GRB 081008, we find the optical extinction in the visual band to be AV˜ 0.19 mag. The curve-of-growth analysis applied to the FORS2 spectra brings column densities consistent at the 3σ level to that evaluated from the UVES data using the line-fitting procedure. This reflects the low saturation of the detected GRB 081008 absorption features. Based on observations collected at the European Southern Observatory, ESO, the VLT/Kueyen telescope, Paranal, Chile, in the framework of the programme 082-0755.

VizieR Online Data Catalog: Star cluster Gaia 1 stars equivalent widths (Koch+, 2018)

NASA Astrophysics Data System (ADS)

Koch, A.; Hansen, T.; Kunder, A.

2017-09-01

Observations of four candidate members were taken during four nights in March 2017 using the Echelle spectrograph at the 2.5-m du Pont telescope at the Las Campanas Observatory, Chile, with a seeing of 0.7"-1.0" throughout the nights. Our spectroscopic set-up included a 1.0" slit with 2x1 binning in spectral and spatial dimensions, resulting in a resolving power of R~25000. (2 data files).

The NASA Exoplanet Science Institute Archives: KOA and NStED

NASA Astrophysics Data System (ADS)

Berriman, G. B.; Ciardi, D.; Abajian, M.; Barlow, T.; Bryden, G.; von Braun, K.; Good, J.; Kane, S.; Kong, M.; Laity, A.; Lynn, M.; Elroy, D. M.; Plavchan, P.; Ramirez, S.; Schmitz, M.; Stauffer, J.; Wyatt, P.; Zhang, A.; Goodrich, R.; Mader, J.; Tran, H.; Tsubota, M.; Beekley, A.; Berukoff, S.; Chan, B.; Lau, C.; Regelson, M.; Saucedo, M.; Swain, M.

2010-12-01

The NASA Exoplanet Science Institute (NExScI) maintains a series of archival services in support of NASA’s planet finding and characterization goals. Two of the larger archival services at NExScI are the Keck Observatory Archive (KOA) and the NASA Star and Exoplanet Database (NStED). KOA, a collaboration between the W. M. Keck Observatory and NExScI, serves raw data from the High Resolution Echelle Spectrograph (HIRES) and extracted spectral browse products. As of June 2009, KOA hosts over 28 million files (4.7 TB) from over 2,000 nights. In Spring 2010, it will begin to serve data from the Near-Infrared Echelle Spectrograph (NIRSPEC). NStED is a general purpose archive with the aim of providing support for NASA’s planet finding and characterization goals, and stellar astrophysics. There are two principal components of NStED: a database of (currently) all known exoplanets, and images; and an archive dedicated to high precision photometric surveys for transiting exoplanets. NStED is the US portal to the CNES mission CoRoT, the first space mission dedicated to the discovery and characterization of exoplanets. These archives share a common software and hardware architecture with the NASA/IPAC Infrared Science Archive (IRSA). The software architecture consists of standalone utilities that perform generic query and retrieval functions. They are called through program interfaces and plugged together to form applications through a simple executive library.

StarCAT: A Catalog of Space Telescope Imaging Spectrograph Ultraviolet Echelle Spectra of Stars

NASA Astrophysics Data System (ADS)

Ayres, Thomas R.

2010-03-01

StarCAT is a catalog of high resolution ultraviolet spectra of objects classified as "stars," recorded by Space Telescope Imaging Spectrograph (STIS) during its initial seven years of operations (1997-2004). StarCAT is based on 3184 echelle observations of 545 distinct targets, with a total exposure duration of 5.2 Ms. For many of the objects, broad ultraviolet coverage has been achieved by splicing echellegrams taken in two or more FUV (1150-1700 Å) and/or NUV (1600-3100 Å) settings. In cases of multiple pointings on conspicuously variable sources, spectra were separated into independent epochs. Otherwise, different epochs were combined to enhance the signal-to-noise ratio (S/N). A post-facto correction to the calstis pipeline data sets compensated for subtle wavelength distortions identified in a previous study of the STIS calibration lamps. An internal "fluxing" procedure yielded coherent spectral energy distributions (SEDs) for objects with broadly overlapping wavelength coverage. The best StarCAT material achieves 300 m s-1 internal velocity precision; absolute accuracy at the 1 km s-1 level; photometric accuracy of order 4%; and relative flux precision several times better (limited mainly by knowledge of SEDs of UV standard stars). While StarCAT represents a milestone in the large-scale post-processing of STIS echellegrams, a number of potential improvements in the underlying "final" pipeline are identified.

Segunda discontinuidad de Balmer y procesos físicos en envolturas extendidas de estrellas Be

NASA Astrophysics Data System (ADS)

Bibbo, I.; Cruzado, A.; Ringuelet, A.

We study a group of Be stars in which the second Balmer jump is observed. Our aim is to correlate the second Balmer jump with other spectral features. Spectroscopic observations were performed with the 2.15 m telescope at Complejo Astronómico el Leoncito, CASLEO (San Juan, Argentina). In December 2001 and August 2002 high resolution echelle spectra were obtained with a REOSC echelle spectrograph. We find that, when a second Balmer jump in emission is observed, an emission in λ = 4233,17 Å of FeII multiplet 27 is also, generally seen. Besides, the electron temperature of the region of the envelope where the second jump is formed is estimated assuming that radiative recombinations cause the flux emission in the Balmer continuum. The temperature values obtained in this way are found correlated with the measure of the second Balmer jump.

VizieR Online Data Catalog: Abundances of bright metal-poor stars (Schlaufman+, 2014)

NASA Astrophysics Data System (ADS)

Schlaufman, K. C.; Casey, A. R.

2016-11-01

As input to our sample selection, we use the APASS DR6 Catalog, the 2MASS All-Sky Point Source Catalog, and the AllWISE Source Catalog (Henden+ 2012JAVSO..40..430H; Skrutskie+ 2006AJ....131.1163S; Wright+ 2010AJ....140.1868W; Mainzer+ 2011ApJ...731...53M). We followed up our metal-poor star candidates with the Mayall 4m/Echelle, Gemini South/GMOS-S, and Magellan/MIKE telescopes and spectrographs. We observed 98 stars with the Mayall 4m/Echelle on 2013 June 25-27. We observed 90 stars with Gemini South/GMOS-S in service mode from 2014 March to July (R~3700). We observed 416 stars with Magellan/MIKE on 2014 June 21-23 and July 8-10 (R~41000 in the blue and R~35000 in the red). (3 data files).

Spectroscopical Study of Faint Southern Cepheids with Southern African Large Telescope (salt). First Results.

NASA Astrophysics Data System (ADS)

Usenko, I. A.; Kniazev, A. Yu.; Kovtyukh, V. V.; Belik, S. I.; Berdnikov, L. N.

First Cepheids observations using echelle-spectrograph HRS fed by Southern African Large Telescope (SALT) were realized during 2016. All spectra have been obtained in the medium resoltion mode (R≍ 31000-41000) wth high S/N ratio near 50-220. All data were processed using package developed by authors based on the standard system of astronomical data reduction MIDAS. Using new echelle data we found the atmosphere parameters and chemical composition for 30 faint Cepheids of southern hemisphere, where for the most of theses stars these results we obtained for the first time. 28 stars are Cepheids after the first-dredge up stage, while ASAS 075842-25336.1 and ASAS 1131714-6605.0 having remarkable Li I 6707.8 Å absorption line and anomalous CNO and Na content could be consider as first crossing of the Cepheids instability strip.

Spectroastrometric Study of Ro-vibrational CO Emission from the Herbig Ae Star HD 179218 with ISHELL on the NASA Infrared Telescope Facility

NASA Astrophysics Data System (ADS)

Brittain, Sean D.; Carr, John S.; Najita, Joan R.

2018-07-01

We present analysis of commissioning M-band data acquired with the infrared echelle spectrograph (iSHELL) on NASA’s Infrared Telescope Facility. In this paper we describe the delivered performance of the instrument for these M-band observations and the data reduction process. The feasibility of using iSHELL for spectro-astrometry is tested on the Herbig Ae/Be star HD 179218 and we show that sub-milliarcsecond fidelity is achievable..

The Atmosphere as Laboratory: Aeronomy by Astronomy

NASA Technical Reports Server (NTRS)

Slanger, T. G.; Cosby, P. C.; Huestis, D. L.

2002-01-01

Astronomical sky spectra, which are byproducts of long-slit observations with echelle spectrographs on large telescopes, provide a unique platform for studying the optical emissions of excited molecules and atoms in the terrestrial atmosphere that can greatly extend present knowledge based on laboratory spectra. This paper summarizes some of the advances that have been made in our understanding of the lower electronic states of O2 and other species from the sky spectra and from direct observations of the Venus nightglow.

The Solar Spectrum 3069A-2095A from the Echelle Spectrograph Flown in 1961-1964. An Extension of Rowland’s Preliminary Table of Solar Spectrum Wavelengths.

DTIC Science & Technology

1982-12-30

Brown S. PERFORMING ORGANIZATION NAME AND ADORESS 10. PROGRAM ELEMENT. PROJECT TASK AREA & WORK UNIT NUMBERS Naval Research Laboratory 61153N...laboratory wavelengths and lished work available to mid-1981. Predicted wavelengths intensities. Although the dispersion was not constant have been used where...solar ledger. Throughout the identification work , how- Multiplet numbers (column 4) are taken from three ever, multiplet structure was considered in

The Spectrum analysis of three chromospherically active binary stars.

NASA Astrophysics Data System (ADS)

Gu, Shenghong; Tan, Huisong; Liu, Yuefu

1999-12-01

The authors present the research results on new CCD spectroscopic observations of three chromospherically active binary stars (BY Dra class), which were obtained by means of Coudé echelle spectrograph fed by the 2.16 m telescope at Beijing Astronomical Observatory. With the aid of stellar model atmosphere, the autors have analyzed these spectra and derived the average metal abundance and Li abundance of three systems. Using two special spectral lines, they have alsop discussed the chromospheric activity indicators of them.

Incrementando la calidad de los espectros echelle

NASA Astrophysics Data System (ADS)

Pintado, O. I.; Adelman, S. J.

For more than 10 years we have obtained spectra with the REOSC and EBASIM spectrograph at CASLEO. Usually we use IRAF to extract the spectra. Then we normalized the 1-d spectra and measured the lines with REDUCE. In this paper we compare the results obtained using each program in different parts of the spectrum measurements process. Wih EBASIM, or 4th magnitude stars and 120 minute exposures we obtain signal-to-noise ratios near 500 in the center of the orders

VizieR Online Data Catalog: Abundances for all seven stars in Latham 1 (O'Connell+, 2016)

NASA Astrophysics Data System (ADS)

O'Connell, J. E.; Martens, K.; Frinchaboy, P. M.

2017-03-01

Observations for all target stars were obtained at McDonald Observatory with the Otto Struve 2.1m telescope instrumented with the Sandiford Cass Echelle Spectrometer (SES; R=λ/Δλ~60000) in 2013 and 2014 June. The spectrograph setup was centered near 6175Å in 2013 and 6375Å in 2014 with wavelength coverage spanning from ~5350-6560Å and ~5560-6750Å, respectively (see Table2 for observation dates and exposure times). (3 data files).

VizieR Online Data Catalog: Abundances in the local region. I. G and K giants (Luck, 2015)

NASA Astrophysics Data System (ADS)

Luck, R. E.

2015-10-01

At the start of this program, the observation list for giants was set to sample the G/K giants of the local region out to about 100pc from the Sun in all directions. The region was subdivided into cubes that were 25pc on a side; from each sub-volume, appropriate stars were selected north of declination -30°. This sample yielded the 286 G/K giants found in Luck et al. 2007 (cat. J/AJ/133/2464). This data set was also augmented by the addition of numerous G/K giants, increasing the number in the 100pc volume to 594 stars. Because the volume selection criteria used in Luck et al. 2007 (cat. J/AJ/133/2464) formally extended out to 115pc, a more precise comparison is that the current sample has 740 stars out to the older limit. Additional stars from the Bright Star Catalog (Hoffleit & Jaschek, 1991bsc..book.....H) were added, driving the sample out to about 200pc. The spectral database was supplemented using the ELODIE and ESO Archives. The ESO addition adds the southern sky. The bulk of the northern stars were observed using the McDonald Observatory Struve Telescope and Sandiford Cassegrain Echelle Spectrograph. For the ELODIE and ESO data archives, a list of all stars available was obtained and spectral type for each from SIMBAD was retrieved. Stars having a spectral type of F, G, or K III were then processed. The ESO data derives from the HARPS and UVES spectrographs. Basic observational data for the program stars can be found in Table1, along with some derived quantities, such as distance. The primary source of observational data for this study is a set of high signal-to-noise ratio (S/N) spectra obtained during numerous observing runs between 1997 and 2010 at McDonald Observatory using the 2.1m Struve Telescope and the Sandiford Cassegrain Echelle Spectrograph. The spectra continuously cover a wavelength range from about 484 to 700nm, with a resolving power of about 60000. Typical S/N values for the spectra are in excess of 150. To enable cancellation of telluric lines, broad-lined B stars were regularly observed with S/N exceeding that of the program stars. The 726 stars observed with the Sandiford spectrograph are marked with an "S" in column "Sce" of Table1. A further 120 spectra were obtained from the ELODIE Archive. These echelle spectra are fully processed through order co-addition with a continuous wavelength span from about 400 to 680 nm and a resolution of 42000. Only spectra with S/N>50 were utilized in this analysis. An "E" in Table1, column "Sce", marks these stars. The ESO Archive was used to obtain spectra from the ESO 3.6m telescope and HARPS spectrograph. The HARPS spectra cover a continuous wavelength range from about 400 to 680nm with a native resolving power of 120000. To match the resolution of the Sandiford data and to increase the S/N of the data, these spectra were co-added to a resolution of 60000. Typical maximum S/N values (per pixel) for the spectra are in excess of 150. In Table1, column "Sce", these stars are marked with an "H." Spectra from the UVES spectrograph and VLT/UT2 were also utilized. These spectra are rather heterogeneous, having resolutions of 40000-80000 and non-continuous spectral coverages in the range 400-700nm. A number of the spectra from UVES stop at about 625nm, meaning that [O I] 630nm and Li I 670nm were not observed. In Table 1, "U" denotes the stars observed with UVES spectrograph. (5 data files).

Research directed toward improved echelles for the ultraviolet. [large space teslescope spectrographs

NASA Technical Reports Server (NTRS)

1977-01-01

Low frequency gratings obtainable with present technology, can meet the grating-efficiency design goals for potential space telescope spectrographs. Gratings made with changes in the three specific parameters: the ruling tool profile, the coating material, and the lubricants used during the ruling process were compared. A series of coatings and test gratings were fabricated and were examined for surface smoothness with a Nomarski differential interference microscope and an electron microsocope. Photomicrographs were obtained to show the difference in smoothness of the various coatings and rulings. Efficiency measurements were made for those test rulings that showed good groove characteristics: smoothness, proper ruling depth, and absence of defects (e.g., streaks, feathered edges and rough sides). Higher grating efficiency should be correlated with the degree of smoothness of both the coating and the grating groove.

Magnetic field geometry and chemical abundance distribution of the He-strong star CPD -57°3509

NASA Astrophysics Data System (ADS)

Hubrig, S.; Przybilla, N.; Korhonen, H.; Ilyin, I.; Schöller, M.; Järvinen, S. P.; Nieva, M.-F.; Scholz, R.-D.; Kimeswenger, S.; Ramolla, M.; Kholtygin, A. F.; Briquet, M.

2017-10-01

The magnetic field of CPD -57°3509 was recently detected in the framework of the BOB (B fields in OB stars) collaboration. We acquired low-resolution spectropolarimetric observations of CPD -57°3509 with the FOcal Reducer low-dispersion Spectrograph 2 and high-resolution UV-Visual Echelle Spectrograph observations randomly distributed over a few months to search for periodicity, to study the magnetic field geometry and to determine the surface distribution of silicon and helium. We also obtained supplementary photometric observations at a timeline similar to the spectroscopic and spectropolarimetric observations. A period of 6.36 d was detected in the measurements of the mean longitudinal magnetic field. A sinusoidal fit to our measurements allowed us to constrain the magnetic field geometry and estimate the dipole strength in the range of 3.9-4.5 kG. Our application of the Doppler imaging technique revealed the presence of He I spots located around the magnetic poles, with a strong concentration at the positive pole and a weaker one around the negative pole. In contrast, high-concentration Si III spots are located close to the magnetic equator. Furthermore, our analysis of the spectral variability of CPD -57°3509 on short time-scales indicates distinct changes in shape and position of line profiles possibly caused by the presence of β Cep like pulsations. A small periodic variability in line with the changes of the magnetic field strength is clearly seen in the photometric data.

New developments in instrumentation at the W. M. Keck Observatory

NASA Astrophysics Data System (ADS)

Adkins, Sean M.; Armandroff, Taft E.; Fitzgerald, Michael P.; Johnson, James; Larkin, James E.; Lewis, Hilton A.; Martin, Christopher; Matthews, Keith Y.; Prochaska, J. X.; Wizinowich, Peter

2014-07-01

The W. M. Keck Observatory continues to develop new capabilities in support of our science driven strategic plan which emphasizes leadership in key areas of observational astronomy. This leadership is a key component of the scientific productivity of our observing community and depends on our ability to develop new instrumentation, upgrades to existing instrumentation, and upgrades to supporting infrastructure at the observatory. In this paper we describe the as measured performance of projects completed in 2014 and the expected performance of projects currently in the development or construction phases. Projects reaching completion in 2014 include a near-IR tip/tilt sensor for the Keck I adaptive optics system, a new center launch system for the Keck II laser guide star facility, and NIRES, a near-IR Echelle spectrograph for the Keck II telescope. Projects in development include a new seeing limited integral field spectrograph for the visible wavelength range called the Keck Cosmic Web Imager, a deployable tertiary mirror for the Keck I telescope, upgrades to the spectrograph detector and the imager of the OSIRIS instrument, and an upgrade to the telescope control systems on both Keck telescopes.

VizieR Online Data Catalog: Spectroscopic Indicators in SeisMic Archive (SISMA) (Rainer+, 2016)

NASA Astrophysics Data System (ADS)

Rainer, M.; Poretti, E.; Misto, A.; Panzera, M. R.; Molinaro, M.; Cepparo, F.; Roth, M.; Michel, E.; Monteiro, M. J. P. F. G.

2017-02-01

We created a large database of physical parameters and variability indicators by fully reducing and analyzing the large number of spectra taken to complement the asteroseismic observations of the COnvection, ROtation and planetary Transits (CoRoT) satellite. CoRoT was launched on 2006 December 27 and it was retired on 2013 June 24. 7103 spectra of 261 stars obtained with the ESO echelle spectrograph High Accuracy Radial velocity Planet Searcher (HARPS) have been stored in the VO-compliant database Spectroscopic Indicators in a SeisMic Archive (SISMA; http://sisma.brera.inaf.it/), along with the CoRoT photometric data of the 72 CoRoT asteroseismic targets. The ground-based activities started with the Large Programme 178.D-0361 using the FEROS spectrograph at the 2.2m telescope of the ESO-La Silla Observatory, and continued with the Large Programmes LP182.D-0356 and LP185.D-0056 using the HARPS instrument at the 3.6m ESO telescope. In the framework of the awarded two HARPS Large Programmes, 15 nights were allocated each semester over nine semesters, from 2008 December to 2013 January, for a total of 135 nights. The HARPS spectrograph covers the spectral range from 3780 to 6910Å, distributed over echelle orders 89-161. We usually used it in the high-efficiency mode EGGS, with resolving power R=80000 to obtain high signal-to-noise ratio (S/N) spectroscopic time series. All of the data (reduced spectra, indicators, and photometric series) are stored as either FITS or PDF files in the SISMA archive and can be accessed at http://sisma.brera.inaf.it/. The data can also be accessed through the Seismic Plus portal (http://voparis-spaceinn.obspm.fr/seismic-plus/), developed in the framework of the SpaceInn project in order to gather and help coordinated access to several different solar and stellar seismic data sources. (1 data file).

Internal kinematic and physical properties in a BCD galaxy: Haro 15 in detail

NASA Astrophysics Data System (ADS)

Firpo, V.; Bosch, G.; Hägele, G. F.; Díaz, A. I.; Morrell, N.

2011-11-01

We present a detailed study of the kinematic and physical properties of the ionized gas in multiple knots of the blue compact dwarf galaxy Haro 15. Using echelle and long slit spectroscopy data, obtained with different instruments at Las Campanas Observatory, we study the internal kinematic and physical conditions (electron density and temperature), ionic and total chemical abundances of several atoms, reddening and ionization structure. Applying direct and empirical methods for abundance determination, we perform a comparative analysis between these regions and in their different components. On the other hand, our echelle spectra show complex kinematics in several conspicuous knots within the galaxy. To perform an in-depth 2D spectroscopic study we complete this work with high spatial and spectral resolution spectroscopy using the Integral Field Unit mode on the Gemini Multi-Object Spectrograph instrument at the Gemini South telescope. With these data we are able to resolve the complex kinematical structure within star forming knots in Haro 15 galaxy.

PEPSI: the Potsdam Echelle Polarimetric and Spectroscopic Instrument for the LBT

NASA Astrophysics Data System (ADS)

Strassmeier, K. G.; Woche, M.; Ilyin, I.; Popow, E.; Bauer, S.-M.; Dionies, F.; Fechner, T.; Weber, M.; Hofmann, A.; Storm, J.; Materne, R.; Bittner, W.; Bartus, J.; Granzer, T.; Denker, C.; Carroll, T.; Kopf, M.; DiVarano, I.; Beckert, E.; Lesser, M.

2008-07-01

We present the status of PEPSI, the bench-mounted fibre-fed and stabilized "Potsdam Echelle Polarimetric and Spectroscopic Instrument" for the 2×8.4m Large Binocular Telescope in southern Arizona. PEPSI is under construction at AIP and is scheduled for first light in 2009/10. Its ultra-high-resolution mode will deliver an unprecedented spectral resolution of approximately R=310,000 at high efficiency throughout the entire optical/red wavelength range 390-1050nm without the need for adaptive optics. Besides its polarimetric Stokes IQUV mode, the capability to cover the entire optical range in three exposures at resolutions of 40,000, 130,000 and 310,000 will surpass all existing facilities in terms of light-gathering-power times spectral-coverage product. A solar feed will make use of the spectrograph also during day time. As such, we hope that PEPSI will be the most powerful spectrometer of its kind for the years to come.

TESS Follow-up Observing Programs at the University of Wyoming

NASA Astrophysics Data System (ADS)

Jang-Condell, Hannah; Kasper, David; Kar, Aman; Sorber, Rebecca; Hancock, Daniel A.; Leuquire, Jacob D.; Suhaimi, Afiq; Kobulnicky, Henry A.; Pierce, Michael; Pilachowski, Catherine A.

2018-06-01

The Transiting Exoplanet Survey Satellite (TESS), launched in Spring 2018, will detect thousands of new exoplanet candidates. These candidates will need to be vetted by ground-based observatories to rule out false positives. The Observatories at the University of Wyoming are well-positioned to take active roles in TESS Follow-Up Observing Program (TFOP) Working Groups. The 0.6-m Red Buttes Observatory has already demonstrated its capability to do precision photometric monitoring of transiting exoplanet targets as a participant in the Kilodegree Extremely Little Telescope Follow-Up Network (KELT-FUN). A new echelle spectrograph, Fiber High-Resolution Echelle (FHiRE), being built for the 2.3-m Wyoming InfraRed Observatory (WIRO), will enable precision radial velocity measurements of exoplanet candidates. Over 180 nights/year at both observatories will be available to our team to undertake follow-up observations of TESS Objects of Interest (TOIs). We anticipate making significant contributions to new exoplanet discoveries in the era of TESS.

16 years of airglow measurement with astronomical facilities

NASA Astrophysics Data System (ADS)

Kausch, Wolfgang; Noll, Stefan; Kimeswenger, Stefan; Unterguggenberger, Stefanie; Jones, Amy; Proxauf, Bastian

2017-04-01

Observations taken with ground-based astronomical telescopes are affected by various airglow emission processes in the Earth's upper atmosphere. This chemiluminescent emission can be used to investigate the physical state of the meso- and the thermosphere. By applying a modified approach of techniques originally developed to characterise and remove these features from the astronomical spectra, which are not primarily taken for airglow studies, these spectra are suitable for airglow research. For our studies, we currently use data from two observing sites on both hemispheres for our studies: The European Southern Observatory operates four 8m telescopes at the Very Large Telescope (VLT) in the Chilean Atacama desert (24.6°S, 70.4°W). The 2.5m Sloan Digital Sky Survey telescope (SDSS) located in New Mexico/USA (32.8°N, 105.8°W) provides observations from the northern hemisphere. Each of these telescopes is equipped with several astronomical instruments. Among them are several spectrographs operating in the optical and near-IR regime with medium to high spectral resolution. Currently, we work on data from the following three spectrographs (1) UVES@VLT (Ultraviolet and Visual Echelle Spectrograph): This instrument provides spectra in the wavelength regime from 0.3 to 1.1μm in small spectral ranges. Its high resolving power (up to R˜110 000) allows a detailed study of oxygen (OI@557nm, OI@630nm), sodium (NaD@589nm), nitrogen (NI@520nm), and many OH bands. UVES has been in operation since 1999 providing the longest time series. (2) X-Shooter@VLT: This spectrograph is unique as it provides the whole wavelength range from 0.3 to 2.5μm at once with medium resolving power (R˜3 300 to 18 000, depending on the setup). This enables us to study the dependency of optical and near-IR airglow processes simultaneously, e.g. the OH bands. In addition, weak airglow continuum emission, e.g. arising from FeO and NiO can be studied. In operation since 2009, the data cover half a solar cycle. (3) MaNGA spectrograph@SDSS: This instrument combines two spectrographs covering the wavelength range from 0.36 to 1.03μm with a resolving power of R˜2 000. It is equipped with a multi-fibre device and is used for this specific survey that started in 2014 (aimed to finish in 2020). In this poster we give an overview on the status of the project, some first results, and an outlook.

Atlas of Vega: 3850-6860 Å

NASA Astrophysics Data System (ADS)

Kim, Hyun-Sook; Han, Inwoo; Valyavin, G.; Lee, Byeong-Cheol; Shimansky, V.; Galazutdinov, G. A.

2009-10-01

We present a high resolving power (λ/Δλ = 90,000) and high signal-to-noise ratio (˜700) spectral atlas of Vega covering the 3850-6860 Å wavelength range. The atlas is a result of averaging of spectra recorded with the aid of the echelle spectrograph BOES fed by the 1.8 m telescope at Bohyunsan Observatory (Korea). The atlas is provided only in machine-readable form (electronic data file) and will be available in the SIMBAD database upon publication. Based on data collected with the 1.8 m telescope operated at BOAO Observatory, Korea.

The Farid & Moussa Raphael Observatory

NASA Astrophysics Data System (ADS)

Hajjar, R.

2017-06-01

The Farid & Moussa Raphael Observatory (FMRO) at Notre Dame University Louaize (NDU) is a teaching, research, and outreach facility located at the main campus of the university. It located very close to the Lebanese coast, in an urbanized area. It features a 60-cm Planewave CDK telescope, and instruments that allow for photometric and spetroscopic studies. The observatory currently has one thinned, back-illuminated CCD camera, used as the main imager along with Johnson-Cousin and Sloan photometric filters. It also features two spectrographs, one of which is a fiber fed echelle spectrograph. These are used with a dedicated CCD. The observatory has served for student projects, and summer schools for advanced undergraduate and graduate students. It is also made available for use by the regional and international community. The control system is currently being configured for remote observations. A number of long-term research projects are also being launched at the observatory.

VizieR Online Data Catalog: Rotation-Activity Correlations in K-M dwarfs II. (Houdebine+, 2017)

NASA Astrophysics Data System (ADS)

Houdebine, E. R.; Mullan, D. J.; Bercu, B.; Paletou, F.; Gebran, M.

2017-10-01

The spectra that we use for determining the CaII and Hα equivalent widths in the present study of dK4-dM4 stars came from three different echelle spectrographs; HARPS (High Accuracy Radial velocity Planet Search, ESO), SOPHIE (OHP), and FEROS (The Fiber-fed Extended Range Optical Spectrograph). The stars in our samples include all stars from all observing programs that have been carried out with HARPS and SOPHIE for stars belonging to the following spectral sub-types: dK4, dK6, dM2, and dM3. For dM4 stars, we compiled all measurements of vsini available in the literature (see Paper I; Houdebine+ 2016, J/ApJ/822/97). For the dK6 and dM3 samples, we also supplemented our own measurements with measurements available in the literature, notably for active stars (see Paper I). (7 data files).

Atomic emission spectrometer/spectrograph for the determination of barium in microamounts of diatom ash

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bankston, D.C.; Fisher, N.S.

1977-06-01

The development and routine application of a method for the determination of trace levels of barium in microsamples (5-10 mg) of diatom ash is described Acid-dissolved lithium metaborate fusion melts of ash samples are analyzed using a spectrometer/spectrograph equipped with a dc argon plasma jet excitation source and an echelle diffraction grating. Sample, standard, and blank solutions are buffered by lithium contributed by the flux, to a degree sufficient to reduce matrix effects to acceptable levels. Previous barium determinations by other analytical techniques, on seven interlaboratory reference materials, have been used to establish the accuracy of our results. The averagemore » relative standard deviation for the instrumental analyses was 0.07. Using recommended instrument settings, moreover, the lowest concentration of barium visible in synthetic standard solutions lies just below 2 ..mu..g/L, which is equivalent to 2 ..mu..g/g in the ash.« less

VizieR Online Data Catalog: L-σ relation for massive star formation (Chavez+, 2014)

NASA Astrophysics Data System (ADS)

Chavez, R.; Terlevich, R.; Terlevich, E.; Bresolin, F.; Melnick, J.; Plionis, M.; Basilakos, S.

2015-03-01

We observed 128 HIIGx selected from the SDSS DR7 spectroscopic catalogue (Abazajian et al., 2009ApJS..182..543A) for having the strongest emission lines relative to the continuum (i.e. largest equivalent widths) and in the redshift range 0.01

Optical design for CETUS: a wide-field 1.5m aperture UV payload being studied for a NASA probe class mission study

NASA Astrophysics Data System (ADS)

Woodruff, Robert A.; Hull, Tony; Heap, Sara R.; Danchi, William; Kendrick, Stephen E.; Purves, Lloyd

2017-09-01

We are developing a NASA Headquarters selected Probe-class mission concept called the Cosmic Evolution Through UV Spectroscopy (CETUS) mission, which includes a 1.5-m aperture diameter large field-of-view (FOV) telescope optimized for UV imaging, multi-object spectroscopy, and point-source spectroscopy. The optical system includes a Three Mirror Anastigmatic (TMA) telescope that simultaneously feeds three separate scientific instruments: the near-UV (NUV) Multi-Object Spectrograph (MOS) with a next-generation Micro-Shutter Array (MSA); the two-channel camera covering the far-UV (FUV) and NUV spectrum; and the point-source spectrograph covering the FUV and NUV region with selectable R 40,000 echelle modes and R 2,000 first order modes. The optical system includes fine guidance sensors, wavefront sensing, and spectral and flat-field in-flight calibration sources. This paper will describe the current optical design of CETUS.

Optical design for CETUS: a wide-field 1.5m aperture UV payload being studied for a NASA probe class mission study

NASA Astrophysics Data System (ADS)

Woodruff, Robert; Robert Woodruff, Goddard Space Flight Center, Kendrick Optical Consulting

2018-01-01

We are developing a NASA Headquarters selected Probe-class mission concept called the Cosmic Evolution Through UV Spectroscopy (CETUS) mission, which includes a 1.5-m aperture diameter large field-of-view (FOV) telescope optimized for UV imaging, multi-object spectroscopy, and point-source spectroscopy. The optical system includes a Three Mirror Anastigmatic (TMA) telescope that simultaneously feeds three separate scientific instruments: the near-UV (NUV) Multi-Object Spectrograph (MOS) with a next-generation Micro-Shutter Array (MSA); the two-channel camera covering the far-UV (FUV) and NUV spectrum; and the point-source spectrograph covering the FUV and NUV region with selectable R~ 40,000 echelle modes and R~ 2,000 first order modes. The optical system includes fine guidance sensors, wavefront sensing, and spectral and flat-field in-flight calibration sources. This paper will describe the current optical design of CETUS.

VizieR Online Data Catalog: Elemental abundances of solar sibling candidates (Ramirez+, 2014)

NASA Astrophysics Data System (ADS)

Ramirez, I.; Bajkova, A. T.; Bobylev, V. V.; Roederer, I. U.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J.; Wittenmyer, R. A.

2017-06-01

We used the Tull coude spectrograph on the 2.7 m Harlan J. Smith Telescope at McDonald Observatory (Tull et al. 1995PASP..107..251T) to observe most of our targets (23). All but three of them were observed in 2012 December; the others were observed in 2013 March. The rest of our targets (seven) have too-low declinations to be observed from McDonald Observatory. Instead, they were observed using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph on the 6.5 m Telescope at Las Campanas Observatory (Bernstein et al. 2003SPIE.4841.1694B) in 2013 April. Slit sizes were chosen so that the spectral resolution of the data is about 60000 in the visible part of the spectrum. We targeted a S/N per pixel of at least 200 at 6000 Å. Only one of our targets (HD 46100) has a significantly lower S/N spectrum. (2 data files).

CARMENES instrument overview

NASA Astrophysics Data System (ADS)

Quirrenbach, A.; Amado, P. J.; Caballero, J. A.; Mundt, R.; Reiners, A.; Ribas, I.; Seifert, W.; Abril, M.; Aceituno, J.; Alonso-Floriano, F. J.; Ammler-von Eiff, M.; Antona Jiménez, R.; Anwand-Heerwart, H.; Azzaro, M.; Bauer, F.; Barrado, D.; Becerril, S.; Béjar, V. J. S.; Benítez, D.; Berdiñas, Z. M.; Cárdenas, M. C.; Casal, E.; Claret, A.; Colomé, J.; Cortés-Contreras, M.; Czesla, S.; Doellinger, M.; Dreizler, S.; Feiz, C.; Fernández, M.; Galadí, D.; Gálvez-Ortiz, M. C.; García-Piquer, A.; García-Vargas, M. L.; Garrido, R.; Gesa, L.; Gómez Galera, V.; González Álvarez, E.; González Hernández, J. I.; Grözinger, U.; Guàrdia, J.; Guenther, E. W.; de Guindos, E.; Gutiérrez-Soto, J.; Hagen, H.-J.; Hatzes, A. P.; Hauschildt, P. H.; Helmling, J.; Henning, T.; Hermann, D.; Hernández Castaño, L.; Herrero, E.; Hidalgo, D.; Holgado, G.; Huber, A.; Huber, K. F.; Jeffers, S.; Joergens, V.; de Juan, E.; Kehr, M.; Klein, R.; Kürster, M.; Lamert, A.; Lalitha, S.; Laun, W.; Lemke, U.; Lenzen, R.; López del Fresno, Mauro; López Martí, B.; López-Santiago, J.; Mall, U.; Mandel, H.; Martín, E. L.; Martín-Ruiz, S.; Martínez-Rodríguez, H.; Marvin, C. J.; Mathar, R. J.; Mirabet, E.; Montes, D.; Morales Muñoz, R.; Moya, A.; Naranjo, V.; Ofir, A.; Oreiro, R.; Pallé, E.; Panduro, J.; Passegger, V.-M.; Pérez-Calpena, A.; Pérez Medialdea, D.; Perger, M.; Pluto, M.; Ramón, A.; Rebolo, R.; Redondo, P.; Reffert, S.; Reinhardt, S.; Rhode, P.; Rix, H.-W.; Rodler, F.; Rodríguez, E.; Rodríguez-López, C.; Rodríguez-Pérez, E.; Rohloff, R.-R.; Rosich, A.; Sánchez-Blanco, E.; Sánchez Carrasco, M. A.; Sanz-Forcada, J.; Sarmiento, L. F.; Schäfer, S.; Schiller, J.; Schmidt, C.; Schmitt, J. H. M. M.; Solano, E.; Stahl, O.; Storz, C.; Stürmer, J.; Suárez, J. C.; Ulbrich, R. G.; Veredas, G.; Wagner, K.; Winkler, J.; Zapatero Osorio, M. R.; Zechmeister, M.; Abellán de Paco, F. J.; Anglada-Escudé, G.; del Burgo, C.; Klutsch, A.; Lizon, J. L.; López-Morales, M.; Morales, J. C.; Perryman, M. A. C.; Tulloch, S. M.; Xu, W.

2014-07-01

This paper gives an overview of the CARMENES instrument and of the survey that will be carried out with it during the first years of operation. CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs) is a next-generation radial-velocity instrument under construction for the 3.5m telescope at the Calar Alto Observatory by a consortium of eleven Spanish and German institutions. The scientific goal of the project is conducting a 600-night exoplanet survey targeting ~ 300 M dwarfs with the completed instrument. The CARMENES instrument consists of two separate echelle spectrographs covering the wavelength range from 0.55 to 1.7 μm at a spectral resolution of R = 82,000, fed by fibers from the Cassegrain focus of the telescope. The spectrographs are housed in vacuum tanks providing the temperature-stabilized environments necessary to enable a 1 m/s radial velocity precision employing a simultaneous calibration with an emission-line lamp or with a Fabry-Perot etalon. For mid-M to late-M spectral types, the wavelength range around 1.0 μm (Y band) is the most important wavelength region for radial velocity work. Therefore, the efficiency of CARMENES has been optimized in this range. The CARMENES instrument consists of two spectrographs, one equipped with a 4k x 4k pixel CCD for the range 0.55 - 1.05 μm, and one with two 2k x 2k pixel HgCdTe detectors for the range from 0.95 - 1.7μm. Each spectrograph will be coupled to the 3.5m telescope with two optical fibers, one for the target, and one for calibration light. The front end contains a dichroic beam splitter and an atmospheric dispersion corrector, to feed the light into the fibers leading to the spectrographs. Guiding is performed with a separate camera; on-axis as well as off-axis guiding modes are implemented. Fibers with octagonal cross-section are employed to ensure good stability of the output in the presence of residual guiding errors. The fibers are continually actuated to reduce modal noise. The spectrographs are mounted on benches inside vacuum tanks located in the coudé laboratory of the 3.5m dome. Each vacuum tank is equipped with a temperature stabilization system capable of keeping the temperature constant to within +/-0.01°C over 24 hours. The visible-light spectrograph will be operated near room temperature, while the near-IR spectrograph will be cooled to ~ 140 K. The CARMENES instrument passed its final design review in February 2013. The MAIV phase is currently ongoing. First tests at the telescope are scheduled for early 2015. Completion of the full instrument is planned for the fall of 2015. At least 600 useable nights have been allocated at the Calar Alto 3.5m Telescope for the CARMENES survey in the time frame until 2018. A data base of M stars (dubbed CARMENCITA) has been compiled from which the CARMENES sample can be selected. CARMENCITA contains information on all relevant properties of the potential targets. Dedicated imaging, photometric, and spectroscopic observations are underway to provide crucial data on these stars that are not available in the literature.

The science case of the PEPSI high-resolution echelle spectrograph and polarimeter for the LBT

NASA Astrophysics Data System (ADS)

Strassmeier, K. G.; Pallavicini, R.; Rice, J. B.; Andersen, M. I.

2004-05-01

We lay out the scientific rationale for and present the instrumental requirements of a high-resolution adaptive-optics Echelle spectrograph with two full-Stokes polarimeters for the Large Binocular Telescope (LBT) in Arizona. Magnetic processes just like those seen on the Sun and in the space environment of the Earth are now well recognized in many astrophysical areas. The application to other stars opened up a new field of research that became widely known as the solar-stellar connection. Late-type stars with convective envelopes are all affected by magnetic processes which give rise to a rich variety of phenomena on their surface and are largely responsible for the heating of their outer atmospheres. Magnetic fields are likely to play a crucial role in the accretion process of T-Tauri stars as well as in the acceleration and collimation of jet-like flows in young stellar objects (YSOs). Another area is the physics of active galactic nucleii (AGNs) , where the magnetic activity of the accreting black hole is now believed to be responsible for most of the behavior of these objects, including their X-ray spectrum, their notoriously dramatic variability, and the powerful relativistic jets they produce. Another is the physics of the central engines of cosmic gamma-ray bursts, the most powerful explosions in the universe, for which the extreme apparent energy release are explained through the collimation of the released energy by magnetic fields. Virtually all the physics of magnetic fields exploited in astrophysics is somehow linked to our understanding of the Sun's and the star's magnetic fields.

GIARPS@TNG: GIANO-B and HARPS-N together for a wider wavelength range spectroscopy

NASA Astrophysics Data System (ADS)

Claudi, R.; Benatti, S.; Carleo, I.; Ghedina, A.; Guerra, J.; Micela, G.; Molinari, E.; Oliva, E.; Rainer, M.; Tozzi, A.; Baffa, C.; Baruffolo, A.; Buchschacher, N.; Cecconi, M.; Cosentino, R.; Fantinel, D.; Fini, L.; Ghinassi, F.; Giani, E.; Gonzalez, E.; Gonzalez, M.; Gratton, R.; Harutyunyan, A.; Hernandez, N.; Lodi, M.; Malavolta, L.; Maldonado, J.; Origlia, L.; Sanna, N.; Sanjuan, J.; Scuderi, S.; Seemann, U.; Sozzetti, A.; Perez Ventura, H.; Hernandez Diaz, M.; Galli, A.; Gonzalez, C.; Riverol, L.; Riverol, C.

2017-08-01

Since 2012, thanks to the installation of the high-resolution echelle spectrograph in the optical range HARPS-N, the Italian telescope TNG (La Palma) became one of the key facilities for the study of the extrasolar planets. In 2014 TNG also offered GIANO to the scientific community, providing a near-infrared (NIR) cross-dispersed echelle spectroscopy covering 0.97-2.45μm at a resolution of 50000. GIANO, although designed for direct light-feed from the telescope at the Nasmyth-B focus, was provisionally mounted on the rotating building and connected via fibers to only available interface at the Nasmyth-A focal plane. The synergy between these two instruments is particularly appealing for a wide range of science cases, especially for the search of exoplanets around young and active stars and the characterisation of their atmosphere. Through the funding scheme "WOW" (a Way to Others Worlds), the Italian National Institute for Astrophysics (INAF) proposed to position GIANO at the focal station for which it was originally designed and the simultaneous use of these spectrographs with the aim to achieve high-resolution spectroscopy in a wide wavelength range (0.383-2.45μm) obtained in a single exposure, giving rise to the project called GIARPS (GIANO-B & HARPS-N). Because of its characteristics, GIARPS can be considered the first and unique worldwide instrument providing not only high resolution in a large wavelength band, but also a high-precision radial velocity measurement both in the visible and in the NIR arm, since in the next future GIANO-B will be equipped with gas absorption cells.

MSE spectrograph optical design: a novel pupil slicing technique

NASA Astrophysics Data System (ADS)

Spanò, P.

2014-07-01

The Maunakea Spectroscopic Explorer shall be mainly devoted to perform deep, wide-field, spectroscopic surveys at spectral resolutions from ~2000 to ~20000, at visible and near-infrared wavelengths. Simultaneous spectral coverage at low resolution is required, while at high resolution only selected windows can be covered. Moreover, very high multiplexing (3200 objects) must be obtained at low resolution. At higher resolutions a decreased number of objects (~800) can be observed. To meet such high demanding requirements, a fiber-fed multi-object spectrograph concept has been designed by pupil-slicing the collimated beam, followed by multiple dispersive and camera optics. Different resolution modes are obtained by introducing anamorphic lenslets in front of the fiber arrays. The spectrograph is able to switch between three resolution modes (2000, 6500, 20000) by removing the anamorphic lenses and exchanging gratings. Camera lenses are fixed in place to increase stability. To enhance throughput, VPH first-order gratings has been preferred over echelle gratings. Moreover, throughput is kept high over all wavelength ranges by splitting light into more arms by dichroic beamsplitters and optimizing efficiency for each channel by proper selection of glass materials, coatings, and grating parameters.

Detection of Gaseous Methane on Pluto

NASA Technical Reports Server (NTRS)

Young, Leslie; Tokunaga, Alan; Elliot, J.; deBergh, Catherine; Owen, Tobias; Witteborn, Fred C. (Technical Monitor)

1995-01-01

We obtained Pluto's spectrum using the CSHELL echelle spectrograph at NASA's IRTF on Mauna Kea, on 25-26 May 1992, with a spectral resolution of 13,300. The spectral range (5998 - 6018 per centimeter, or 1661.8 - 1666.9 nm) includes the R(0) and the Q(1) - Q(9) lines of the 2v3 band of methane. The resulting spectrum shows the first detection of gaseous methane on Pluto, with a column height of 1.20 (sup +3.15) (sub -0.87) cm-A (3.22 (sup +8.46) (sub -2.34) x 10(exp 19) molecule per square centimeter)).

VizieR Online Data Catalog: Vi' LCs and RVs of the EB star TYC 5227-1023-1 (Traven+, 2017)

NASA Astrophysics Data System (ADS)

Traven, G.; Munari, U.; Dallaporta, S.; Zwitter, T.

2017-11-01

CCD photometry in the Landolt V and SLOAN i' bands of TYC5227-1023-1 has been obtained with ANS Collaboration telescope N.36 located in Cembra (Trento, Italy). Spectra of TYC 5227-1023-1 were secured in 2015-2016 with the Echelle+CCD spectrograph mounted on the 1.82m telescope operated by Osservatorio Astronomico di Padova atop Mt. Ekar (Asiago). Here we recall that the 3600-7400Å wavelength region is covered in 30 orders at a resolving power of 20000. (2 data files).

SALT Spectroscopy of Evolved Massive Stars

NASA Astrophysics Data System (ADS)

Kniazev, A. Y.; Gvaramadze, V. V.; Berdnikov, L. N.

2017-06-01

Long-slit spectroscopy with the Southern African Large Telescope (SALT) of central stars of mid-infrared nebulae detected with the Spitzer Space Telescope and Wide-Field Infrared Survey Explorer (WISE) led to the discovery of numerous candidate luminous blue variables (cLBVs) and other rare evolved massive stars. With the recent advent of the SALT fiber-fed high-resolution echelle spectrograph (HRS), a new perspective for the study of these interesting objects is appeared. Using the HRS we obtained spectra of a dozen newly identified massive stars. Some results on the recently identified cLBV Hen 3-729 are presented.

Development of public science archive system of Subaro Telescope. 2

NASA Astrophysics Data System (ADS)

Yamamoto, Naotaka; Noda, Sachiyo; Taga, Masatoshi; Ozawa, Tomohiko; Horaguchi, Toshihiro; Okumura, Shin-Ichiro; Furusho, Reiko; Baba, Hajime; Yagi, Masafumi; Yasuda, Naoki; Takata, Tadafumi; Ichikawa, Shin-Ichi

2003-09-01

We report various improvements in a public science archive system, SMOKA (Subaru-Mitaka-Okayama-Kiso Archive system). We have developed a new interface to search observational data of minor bodies in the solar system. In addition, the other improvements (1) to search frames by specifying wavelength directly, (2) to find out calibration data set automatically, (3) to browse data on weather, humidity, and temperature, which provide information of image quality, (4) to provide quick-look images of OHS/CISCO and IRCS, and (5) to include the data from OAO HIDES (HIgh Dispersion Echelle Spectrograph), are also summarized.

VizieR Online Data Catalog: Spectra of KIC10661783 (Lehmann+, 2013)

NASA Astrophysics Data System (ADS)

Lehmann, H.; Southworth, J.; Tkachenko, A.; Pavlovski, K.

2013-08-01

In 2010, we obtained 26 high-resolution spectra of KIC 10661783 in seven almost consecutive nights using the Coude-echelle spectrograph at the 2-m telescope of the Thueringer Landessternwarte Tautenburg. The spectra have a resolving power of 64000 and cover the wavelength range 470-740nm. The exposure time was 30 min and the spectra have a signal-to-noise ratio of 90 on average. They were reduced using standard ESO-MIDAS packages and a routine for the calibration of the instrumental radial velocity zero-point using O2 telluric lines. (2 data files).

Spectra of Th/Ar and U/Ne hollow cathode lamps for spectrograph calibration

NASA Astrophysics Data System (ADS)

Nave, Gillian; Shlosberg, Ariel; Kerber, Florian; Den Hartog, Elizabeth; Neureiter, Bianca

2018-01-01

Low-current Th/Ar hollow cathode lamps have long been used for calibration of astronomical spectrographs on ground-based telescopes. Thorium is an attractive element for calibration as it has a single isotope, has narrow spectral lines, and has a dense spectrum covering the whole of the visible region. However, the high density of the spectrum that makes it attractive for calibrating high-resolution spectrographs is a detriment for lower resolution spectrographs and this is not obvious by examination of existing linelists. In addition, recent changes in regulations regarding the handling of thorium have led to a degradation in the quality of Th/Ar calibration lamps, with contamination by molecular ThO lines that are strong enough to obscure the calibration lines of interest.We are pursuing two approaches to these problems. First, we have expanded and improved the NIST Standard Reference Database 161, "Spectrum of Th-Ar Hollow Cathode Lamps" to cover the region 272 nm to 5500 nm. Spectra of hollow cathode lamps at up to 3 different currents can now be displayed simultaneously. Interactive zooming and the ability to convolve any of the spectra with a Gaussian or uploaded instrument profile enable the user to see immediately what the spectrum would look like at the particular resolution of their spectrograph. Second, we have measured the spectrum of a recent, contaminated Th/Ar hollow cathode lamp using a high-resolution Echelle spectrograph (Madison Wisconsin) at a resolving power (R~ 250,000). This significantly exceeds the resolving power of most astronomical spectrographs and resolves many of the molecular lines of ThO. With these spectra we are measuring and calibrating the positions of these molecular lines in order to make them suitable for spectrograph calibration.In the near infrared region, U/Ne hollow cathode lamps give a higher density of calibration lines than Th/Ar lamps and will be implemented on the upgraded CRIRES+ spectrograph on ESO’s Very Large Telescope in Chile. A new atlas of the U/Ne spectrum as measured by CRIRES will be presented.

The formation and evolution of high-redshift dusty galaxies

NASA Astrophysics Data System (ADS)

Ma, Jingzhe; Gonzalez, Anthony H.; Ge, Jian; Vieira, Joaquin D.; Prochaska, Jason X.; Spilker, Justin; Strandet, Maria; Ashby, Matthew; Noterdaeme, Pasquier; Lundgren, Britt; Zhao, Yinan; Ji, Tuo; Zhang, Shaohua; Caucal, Paul; SPT SMG Collaboration

2017-01-01

Star formation and chemical evolution are among the biggest questions in galaxy formation and evolution. High-redshift dusty galaxies are the best sites to investigate mass assembly and growth, star formation rates, star formation history, chemical enrichment, and physical conditions. My thesis is based on two populations of high-redshift dusty galaxies, submillimeter galaxies (SMGs) and quasar 2175 Å dust absorbers, which are selected by dust emission and dust absorption, respectively.For the SMG sample, I have worked on the gravitationally lensed dusty, star-forming galaxies (DSFGs) at 2.8 < z < 5.7, which were first discovered by the South Pole Telescope (SPT) and further confirmed by ALMA. My thesis is focused on the stellar masses and star formation rates of these objects by means of multi-wavelength spectral energy distribution (SED) modelling. The data include HST/WFC3, Spitzer/IRAC, Herschel/PACS, Herschel/SPIRE, APEX/Laboca and SPT. Compared to the star-forming main sequence (MS), these DSFGs have specific SFRs that lie above the MS, suggesting that we are witnessing ongoing strong starburst events that may be driven by major mergers. SPT0346-52 at z = 5.7, the most extraordinary source in the SPT survey for which we obtained Chandra X-ray and ATCA radio data, was confirmed to have the highest star formation surface density of any known galaxy at high-z.The other half of my thesis is focused on a new population of quasar absorption line systems, 2175 Å dust absorbers, which are excellent probes of gas and dust properties, chemical evolution and physical conditions in the absorbing galaxies. This sample was selected from the SDSS and BOSS surveys and followed up with the Echelle Spectrographs and Imager on the Keck-II telescope, the Red & Blue Channel Spectrograph on the Multiple Mirror Telescope, and the Ultraviolet and Visible Echelle Spectrograph onboard the Very Large Telescope. We found a correlation between the presence of the 2175 Å bump and other ingredients including high metallicity, high depletion level, overall low ionization state of gas, neutral carbon and molecules. I have also pushed forward this study by using HST IR grism to link the absorber and the host galaxy.

Eta Carinae: Viewed from Multiple Vantage Points

NASA Technical Reports Server (NTRS)

Gull, Theodore

2007-01-01

The central source of Eta Carinae and its ejecta is a massive binary system buried within a massive interacting wind structure which envelops the two stars. However the hot, less massive companion blows a small cavity in the very massive primary wind, plus ionizes a portion of the massive wind just beyond the wind-wind boundary. We gain insight on this complex structure by examining the spatially-resolved Space Telescope Imaging Spectrograph (STIS) spectra of the central source (0.1") with the wind structure which extends out to nearly an arcsecond (2300AU) and the wind-blown boundaries, plus the ejecta of the Little Homunculus. Moreover, the spatially resolved Very Large Telescope/UltraViolet Echelle Spectrograph (VLT/UVES) stellar spectrum (one arcsecond) and spatially sampled spectra across the foreground lobe of the Homunculus provide us vantage points from different angles relative to line of sight. Examples of wind line profiles of Fe II, and the.highly excited [Fe III], [Ne III], [Ar III] and [S III)], plus other lines will be presented.

VizieR Online Data Catalog: Abundances of 8 RR Lyrae subclass C variable stars (Govea+, 2014)

NASA Astrophysics Data System (ADS)

Govea, J.; Gomez, T.; Preston, G. W.; Sneden, C.

2016-02-01

We chose 10 candidate RR Lyrae variable stars of subclass c (RRc) stars for spectroscopic observation. Many of these stars were first identified as RRc variables by the All Sky Automated Survey (ASAS) of Pojmanski 2003 (cat. II/264). The target star list included ASAS 144154-0324.7 and ASAS 204440-2402.7. But our spectroscopic study suggest that these two stars are probably W UMa binaries instead of RR Lyrae stars Our spectra were obtained with the echelle spectrograph of the du Pont 2.5m telescope at the Las Campanas Observatory. Four observing runs during 2009-2010 were partly devoted to this project. The spectrograph was used with the 1.5*4'' entrance slit, which translates to a resolving power of R=λ/Δλ~27000 at the MgI b lines near 5180Å. The total continuous wavelength coverage of the spectra was 3500-9000Å. (6 data files).

A Moire Fringing Spectrometer for Extra-Solar Planet Searches

NASA Astrophysics Data System (ADS)

van Eyken, J. C.; Ge, J.; Mahadevan, S.; De Witt, C.; Ramsey, L. W.; Berger, D.; Shaklan, S.; Pan, X.

2001-12-01

We have developed a prototype moire fringing spectrometer for high precision radial velocity measurements for the detection of extra-solar planets. This combination of Michelson interferometer and spectrograph overlays an interferometer comb on a medium resolution stellar spectrum, producing Moire patterns. Small changes in the doppler shift of the spectrum lead to corresponding large shifts in the Moire pattern (Moire magnification). The sinusoidal shape of the Moire fringes enables much simpler measurement of these shifts than in standard echelle spectrograph techniques, facilitating high precision measurements with a low cost instrument. Current data analysis software we have developed has produced short-term repeatability (over a few hours) to 5-10m/s, and future planned improvements based on previous experiments should reduce this significantly. We plan eventually to carry out large scale surveys for low mass companions around other stars. This poster will present new results obtained in the lab and at the HET and Palomar 5m telescopes, the theory of the instrument, and data analysis techniques.

Constraint on a varying proton-to-electron mass ratio from molecular hydrogen absorption towards quasar SDSS J123714.60+064759.5

NASA Astrophysics Data System (ADS)

Daprà, M.; Bagdonaite, J.; Murphy, M. T.; Ubachs, W.

2015-11-01

Molecular hydrogen transitions in the sub-damped Lyman α absorber at redshift zabs ≃ 2.69, towards the background quasar SDSS J123714.60+064759.5, were analysed in order to search for a possible variation of the proton-to-electron mass ratio μ over a cosmological time-scale. The system is composed of three absorbing clouds where 137 H2 and HD absorption features were detected. The observations were taken with the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph with a signal-to-noise ratio of 32 per 2.5 km s-1 pixel, covering the wavelengths from 356.6 to 409.5 nm. A comprehensive fitting method was used to fit all the absorption features at once. Systematic effects of distortions to the wavelength calibrations were analysed in detail from measurements of asteroid and `solar twin' spectra, and were corrected for. The final constraint on the relative variation in μ between the absorber and the current laboratory value is Δμ/μ = (-5.4 ± 6.3stat ± 4.0syst) × 10-6, consistent with no variation over a look-back time of 11.4 Gyr.

Accretion and Diffusion in the DAZ White Dwarf GALEX J1931+0117

NASA Astrophysics Data System (ADS)

Vennes, Stéphane; Kawka, Adéla; Németh, Péter

2011-03-01

We present an analysis of high-dispersion and high signal-to-noise ratio spectra of the DAZ white dwarf GALEX J1931+0117. The spectra obtained with the VLT-Kueyen/UV-Visual Echelle Spectrograph show several well-resolved Si II spectral lines enabling a study of pressure effects on line profiles. We observed large Stark shifts in silicon lines in agreement with laboratory measurements. A model atmosphere analysis shows that the magnesium, silicon and iron abundances exceed solar abundances, while the oxygen and calcium abundances are below solar. Also, we compared the observed line profiles to synthetic spectra computed with variable accretion rates and vertical abundance distributions assuming diffusion steady-state. The inferred accretion rates vary from Ṁ = 2×106 for calcium to 2×109 g s-1 for oxygen and indicate that the accretion flow is dominated by oxygen, silicon and iron while being deficient in carbon, magnesium and calcium. The lack of radial velocity variations between two measurement epochs suggests that GALEX J1931+0117 is probably not in a close binary and that the source of the accreted material resides in a debris disc.

New high-precision orbital and physical parameters of the double-lined low-mass spectroscopic binary BY Draconis

NASA Astrophysics Data System (ADS)

Hełminiak, K. G.; Konacki, M.; Muterspaugh, M. W.; Browne, S. E.; Howard, A. W.; Kulkarni, S. R.

2012-01-01

We present the most precise to date orbital and physical parameters of the well-known short period (P= 5.975 d), eccentric (e= 0.3) double-lined spectroscopic binary BY Draconis (BY Dra), a prototype of a class of late-type, active, spotted flare stars. We calculate the full spectroscopic/astrometric orbital solution by combining our precise radial velocities (RVs) and the archival astrometric measurements from the Palomar Testbed Interferometer (PTI). The RVs were derived based on the high-resolution echelle spectra taken between 2004 and 2008 with the Keck I/high-resolution echelle spectrograph, Shane/CAT/HamSpec and TNG/SARG telescopes/spectrographs using our novel iodine-cell technique for double-lined binary stars. The RVs and available PTI astrometric data spanning over eight years allow us to reach 0.2-0.5 per cent level of precision in Msin 3i and the parallax but the geometry of the orbit (i≃ 154°) hampers the absolute mass precision to 3.3 per cent, which is still an order of magnitude better than for previous studies. We compare our results with a set of Yonsei-Yale theoretical stellar isochrones and conclude that BY Dra is probably a main-sequence system more metal rich than the Sun. Using the orbital inclination and the available rotational velocities of the components, we also conclude that the rotational axes of the components are likely misaligned with the orbital angular momentum. Given BY Dra's main-sequence status, late spectral type and the relatively short orbital period, its high orbital eccentricity and probable spin-orbit misalignment are not in agreement with the tidal theory. This disagreement may possibly be explained by smaller rotational velocities of the components and the presence of a substellar mass companion to BY Dra AB.

A Decade Of Teacher Professional Development With SOFIA's EXES And TEXES

NASA Astrophysics Data System (ADS)

Hemenway, Mary Kay; Lacy, J. H.; Sneden, C.; Teacher Associates, EXES

2007-12-01

Since January 1998 central Texas grade 6-12 science and math teachers have met several times per year to learn first-hand about how a scientific instrument, the Echelon Cross Echelle Spectrograph (EXES), is being developed and built for SOFIA. In addition to learning about the technology of astronomical instrumentation, they have learned about the development of SOFIA, the scheduling and preparation for observing runs, and a wide range of astronomical topics. A typical Saturday meeting includes an update on SOFIA, EXES, and its ground-based prototype, TEXES (Texas Echelon Cross Echelle Spectrograph); one or more presentations on a science or technology topic; and a Standards-linked activity that they can carry back to use in their classrooms. A variety of guest-presenters - faculty, staff, and graduate students as well as visitors (e. g., Jackie Davidson and Alan Tokunaga) - enrich the program with their expertise. Field trips are important supplements to the program; the entire group visited Waco three times to observe the SOFIA aircraft modification while selected members have accompanied scientists to McDonald Observatory, IRTF, and Gemini for observing runs. In addition, the immediacy offered by live videoconferences with TEXES observers at IRTF and Gemini brought the participants a unique appreciation of nighttime observing at a professional observatory. The participants report their increased knowledge of astronomical concepts and of the culture of professional astronomy. By spreading the SOFIA EXES teacher program over its first decade of development, the staff has formed strong professional bonds with the participants while the participants have shared their experiences with each other. Support from USRA grant 8500-98-008 and the National Science Foundation AST-0607312 and AST- 0607708 is gratefully acknowledged.

Exoplanet Transits of Stellar Active Regions

NASA Astrophysics Data System (ADS)

Giampapa, Mark S.; Andretta, Vincenzo; Covino, Elvira; Reiners, Ansgar; Esposito, Massimiliano

2018-01-01

We report preliminary results of a program to obtain high spectral- and temporal-resolution observations of the neutral helium triplet line at 1083.0 nm in transiting exoplanet systems. The principal objective of our program is to gain insight on the properties of active regions, analogous to solar plages, on late-type dwarfs by essentially using exoplanet transits as high spatial resolution probes of the stellar surface within the transit chord. The 1083 nm helium line is a particularly appropriate diagnostic of magnetized areas since it is weak in the quiet photosphere of solar-type stars but appears strongly in absorption in active regions. Therefore, during an exoplanet transit over the stellar surface, variations in its absorption equivalent width can arise that are functions of the intrinsic strength of the feature in the active region and the known relative size of the exoplanet. We utilized the Galileo Telescope and the GIANO-B near-IR echelle spectrograph to obtain 1083 nm spectra during transits in bright, well-known systems that include HD 189733, HD 209458, and HD 147506 (HAT-P-2). We also obtained simultaneous auxiliary data on the same telescope with the HARPS-N UV-Visible echelle spectrograph. We will present preliminary results from our analysis of the observed variability of the strength of the He I 1083 nm line during transits.Acknowledgements: Based on observations made with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. The NSO is operated by AURA under a cooperative agreement with the NSF.

Unexpected series of regular frequency spacing of δ Scuti stars in the non-asymptotic regime. II. Sample-Echelle diagrams and rotation

DOE PAGES

Paparo, M.; Benko, J. M.; Hareter, M.; ...

2016-06-17

A sequence search method was developed for searching for regular frequency spacing in δ Scuti stars by visual inspection (VI) and algorithmic search. The sample contains 90 δ Scuti stars observed by CoRoT. An example is given to represent the VI. The algorithm (SSA) is described in detail. The data treatment of the CoRoT light curves, the criteria for frequency filtering, and the spacings derived by two methods (i.e., three approaches: VI, SSA, and FT) are given for each target. Echelle diagrams are presented for 77 targets for which at least one sequence of regular spacing was identified. Comparing the spacing and the shifts between pairs of echelle ridges revealed that at least one pair of echelle ridges is shifted to midway between the spacing for 22 stars. The estimated rotational frequencies compared to the shifts revealed rotationally split doublets, triplets, and multiplets not only for single frequencies, but for the complete echelle ridges in 31 δ Scuti stars. Furthermore, using several possible assumptions for the origin of the spacings, we derived the large separation (more » $${\\rm{\\Delta }}\

Unexpected series of regular frequency spacing of δ Scuti stars in the non-asymptotic regime. II. Sample-Echelle diagrams and rotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paparo, M.; Benko, J. M.; Hareter, M.

A sequence search method was developed for searching for regular frequency spacing in δ Scuti stars by visual inspection (VI) and algorithmic search. The sample contains 90 δ Scuti stars observed by CoRoT. An example is given to represent the VI. The algorithm (SSA) is described in detail. The data treatment of the CoRoT light curves, the criteria for frequency filtering, and the spacings derived by two methods (i.e., three approaches: VI, SSA, and FT) are given for each target. Echelle diagrams are presented for 77 targets for which at least one sequence of regular spacing was identified. Comparing the spacing and the shifts between pairs of echelle ridges revealed that at least one pair of echelle ridges is shifted to midway between the spacing for 22 stars. The estimated rotational frequencies compared to the shifts revealed rotationally split doublets, triplets, and multiplets not only for single frequencies, but for the complete echelle ridges in 31 δ Scuti stars. Furthermore, using several possible assumptions for the origin of the spacings, we derived the large separation (more » $${\\rm{\\Delta }}\

Effect of Training Japanese L1 Speakers in the Production of American English /r/ Using Spectrographic Visual Feedback

ERIC Educational Resources Information Center

Patten, Iomi; Edmonds, Lisa A.

2015-01-01

The present study examines the effects of training native Japanese speakers in the production of American /r/ using spectrographic visual feedback. Within a modified single-subject design, two native Japanese participants produced single words containing /r/ in a variety of positions while viewing live spectrographic feedback with the aim of…

High resolution broad-band spectroscopy in the NIR using the Triplespec externally dispersed interferometer at the Hale telescope

NASA Astrophysics Data System (ADS)

Erskine, David J.; Edelstein, J.; Sirk, M.; Wishnow, E.; Ishikawa, Y.; McDonald, E.; Shourt, W. V.

2014-07-01

High resolution broad-band spectroscopy at near-infrared wavelengths has been performed using externally dis- persed interferometry (EDI) at the Hale telescope at Mt. Palomar. The EDI technique uses a field-widened Michelson interferometer in series with a dispersive spectrograph, and is able to recover a spectrum with a resolution 4 to 10 times higher than the existing grating spectrograph. This method increases the resolution well beyond the classical limits enforced by the slit width and the detector pixel Nyquist limit and, in principle, decreases the effect of pupil variation on the instrument line-shape function. The EDI technique permits arbi- trarily higher resolution measurements using the higher throughput, lower weight, size, and expense of a lower resolution spectrograph. Observations of many stars were performed with the TEDI interferometer mounted within the central hole of the 200 inch primary mirror. Light from the interferometer was then dispersed by the TripleSpec near-infrared echelle spectrograph. Continuous spectra between 950 and 2450 nm with a resolution as high as ~27,000 were recovered from data taken with TripleSpec at a native resolution of ˜2,700. Aspects of data analysis for interferometric spectral reconstruction are described. This technique has applications in im- proving measurements of high-resolution stellar template spectra, critical for precision Doppler velocimetry using conventional spectroscopic methods. A new interferometer to be applied for this purpose at visible wavelengths is under construction.

Using confidence intervals to evaluate the focus alignment of spectrograph detector arrays.

PubMed

Sawyer, Travis W; Hawkins, Kyle S; Damento, Michael

2017-06-20

High-resolution spectrographs extract detailed spectral information of a sample and are frequently used in astronomy, laser-induced breakdown spectroscopy, and Raman spectroscopy. These instruments employ dispersive elements such as prisms and diffraction gratings to spatially separate different wavelengths of light, which are then detected by a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detector array. Precise alignment along the optical axis (focus position) of the detector array is critical to maximize the instrumental resolution; however, traditional approaches of scanning the detector through focus lack a quantitative measure of precision, limiting the repeatability and relying on one's experience. Here we propose a method to evaluate the focus alignment of spectrograph detector arrays by establishing confidence intervals to measure the alignment precision. We show that propagation of uncertainty can be used to estimate the variance in an alignment, thus providing a quantitative and repeatable means to evaluate the precision and confidence of an alignment. We test the approach by aligning the detector array of a prototype miniature echelle spectrograph. The results indicate that the procedure effectively quantifies alignment precision, enabling one to objectively determine when an alignment has reached an acceptable level. This quantitative approach also provides a foundation for further optimization, including automated alignment. Furthermore, the procedure introduced here can be extended to other alignment techniques that rely on numerically fitting data to a model, providing a general framework for evaluating the precision of alignment methods.

The Magellan Telescopes

NASA Astrophysics Data System (ADS)

Shectman, Stephen A.; Johns, Matthew

2003-02-01

Commissioning of the two 6.5-meter Magellan telescopes is nearing completion at the Las Campanas Observatory in Chile. The Magellan 1 primary mirror was successfully aluminized at Las Campanas in August 2000. Science operations at Magellan 1 began in February 2001. The second Nasmyth focus on Magellan 1 went into operation in September 2001. Science operations on Magellan 2 are scheduled to begin shortly. The ability to deliver high-quality images is maintained at all times by the simultaneous operation of the primary mirror support system, the primary mirror thermal control system, and a real-time active optics system, based on a Shack-Hartmann image analyzer. Residual aberrations in the delivered image (including focus) are typically 0.10-0.15" fwhm, and real images as good as 0.25" fwhm have been obtained at optical wavelengths. The mount points reliably to 2" rms over the entire sky, using a pointing model which is stable from year to year. The tracking error under typical wind conditions is better than 0.03" rms, although some degradation is observed under high wind conditions when the dome is pointed in an unfavorable direction. Instruments used at Magellan 1 during the first year of operation include two spectrographs previously used at other telescopes (B&C, LDSS-2), a mid-infrared imager (MIRAC) and an optical imager (MAGIC, the first Magellan-specific facility instrument). Two facility spectrographs are scheduled to be installed shortly: IMACS, a wide-field spectrograph, and MIKE, a double echelle spectrograph.

Eta Carinae across the 2003.5 Minimum: Analysis in the Visible and Near Infrared Spectral Region

NASA Technical Reports Server (NTRS)

Nielsen, K. E.; Kober, G. Vieira; Weis, K.; Gull, T.; Stahl, O.; Bomans, D. J.

2008-01-01

We present analysis of the visible through near infrared spectrum of eta Car and its ejecta obtained during the 'eta Car Campaign with the Ultraviolet Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT)'. This is a part of larger effort to present a complete eta Car spectrum, and extends the previously presented analyses with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) in the UV (1240-3159 A) to 10,430 A. The spectrum in the mid and near UV is characterized by the ejecta absorption. At longer wavelengths, stellar wind features from the central source and narrow emission lines from the Weigelt condensations dominate the spectrum. However, narrow absorption lines from the circumstellar shells are present. This paper provides a description of the spectrum between 3060 and 10,430 A, including line identifications of the ejecta absorption spectrum, the emission spectrum from the Weigelt condensations and the P-Cygni stellar wind features. The high spectral resolving power of VLT/UVES enables equivalent width measurements of atomic and molecular absorption lines for elements with no transitions at the shorter wavelengths. However, the ground based seeing and contributions of nebular scattered radiation prevent direct comparison of measured equivalent widths in the VLT/UVES and HST/STIS spectra. Fortunately, HST/STIS and VLT/UVES have a small overlap in wavelength coverage which allows us to compare and adjust for the difference in scattered radiation entering the instruments apertures. This paper provide a complete online VLT/UVES spectrum with line identifications and a spectral comparison between HST/STIS and VLT/UVES between 3060 and 3160 A.

Eta Carinae across the 2003.5 Minimum: Analysis in the Visible and Near Infrared Spectral Region

NASA Technical Reports Server (NTRS)

Nielsen, K. E.; Kober, G. Vieira; Weis, K.; Gull, T. R.; Stahl, O.; Bomans, D. J.

2009-01-01

We present an analysis of the visible through near infrared spectrum of Eta Car and its ejecta obtained during the "Eta Car Campaign with the Ultraviolet and Visual Echelle Spectrograph (UVES) at the ESO Very Large Telescope (VLT)". This is a part of the larger effort to present a complete Eta Car spectrum, and extends the previously presented analyses with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) in the UV (1240-3159 Angstrom) to 10,430 Angstrom. The spectrum in the mid and near UV is characterized by the ejecta absorption. At longer wavelengths, stellar wind features from the central source and narrow emission lines from the Weigelt condensations dominate the spectrum. However, narrow absorption lines from the circumstellar shells are present. This paper provides a description of the spectrum between 3060 and 10,430 Angstroms, including line identifications of the ejecta absorption spectrum, the emission spectrum from the Weigelt condensations and the P-Cygni stellar wind features. The high spectral resolving power of VLT/UVES enables equivalent width measurements of atomic and molecular absorption lines for elements with no transitions at the shorter wavelengths. However, the ground based seeing and contributions of nebular scattered radiation prevent direct comparison of measured equivalent widths in the VLT/UVES and HST/STIS spectra. Fortunately, HST/STIS and VLT/UVES have a small overlap in wavelength coverage which allows us to compare and adjust for the difference in scattered radiation entering the instruments' apertures. This paper provides a complete online VLT/UVES spectrum with line identifications and a spectral comparison between HST/STIS and VLT/UVES between 3060 and 3160 Angstroms.

Planet Detectability in the Alpha Centauri System

NASA Astrophysics Data System (ADS)

Zhao, Lily; Fischer, Debra A.; Brewer, John; Giguere, Matt; Rojas-Ayala, Bárbara

2018-01-01

We use more than a decade of radial-velocity measurements for α {Cen} A, B, and Proxima Centauri from the High Accuracy Radial Velocity Planet Searcher, CTIO High Resolution Spectrograph, and the Ultraviolet and Visual Echelle Spectrograph to identify the M\\sin i and orbital periods of planets that could have been detected if they existed. At each point in a mass–period grid, we sample a simulated, Keplerian signal with the precision and cadence of existing data and assess the probability that the signal could have been produced by noise alone. Existing data places detection thresholds in the classically defined habitable zones at about M\\sin i of 53 {M}\\oplus for α {Cen} A, 8.4 {M}\\oplus for α {Cen} B, and 0.47 {M}\\oplus for Proxima Centauri. Additionally, we examine the impact of systematic errors, or “red noise” in the data. A comparison of white- and red-noise simulations highlights quasi-periodic variability in the radial velocities that may be caused by systematic errors, photospheric velocity signals, or planetary signals. For example, the red-noise simulations show a peak above white-noise simulations at the period of Proxima Centauri b. We also carry out a spectroscopic analysis of the chemical composition of the α {Centauri} stars. The stars have super-solar metallicity with ratios of C/O and Mg/Si that are similar to the Sun, suggesting that any small planets in the α {Cen} system may be compositionally similar to our terrestrial planets. Although the small projected separation of α {Cen} A and B currently hampers extreme-precision radial-velocity measurements, the angular separation is now increasing. By 2019, α {Cen} A and B will be ideal targets for renewed Doppler planet surveys.

Quantitative spectroscopy of extreme helium stars Model atmospheres and a non-LTE abundance analysis of BD+10°2179

NASA Astrophysics Data System (ADS)

Kupfer, T.; Przybilla, N.; Heber, U.; Jeffery, C. S.; Behara, N. T.; Butler, K.

2017-10-01

Extreme helium stars (EHe stars) are hydrogen-deficient supergiants of spectral type A and B. They are believed to result from mergers in double degenerate systems. In this paper, we present a detailed quantitative non-LTE spectral analysis for BD+10°2179, a prototype of this rare class of stars, using UV-Visual Echelle Spectrograph and Fiber-fed Extended Range Optical Spectrograph spectra covering the range from ˜3100 to 10 000 Å. Atmosphere model computations were improved in two ways. First, since the UV metal line blanketing has a strong impact on the temperature-density stratification, we used the atlas12 code. Additionally, We tested atlas12 against the benchmark code sterne3, and found only small differences in the temperature and density stratifications, and good agreement with the spectral energy distributions. Secondly, 12 chemical species were treated in non-LTE. Pronounced non-LTE effects occur in individual spectral lines but, for the majority, the effects are moderate to small. The spectroscopic parameters give Teff =17 300±300 K and log g = 2.80±0.10, and an evolutionary mass of 0.55±0.05 M⊙. The star is thus slightly hotter, more compact and less massive than found in previous studies. The kinematic properties imply a thick-disc membership, which is consistent with the metallicity [Fe/H] ≈ -1 and α-enhancement. The refined light-element abundances are consistent with the white dwarf merger scenario. We further discuss the observed helium spectrum in an appendix, detecting dipole-allowed transitions from about 150 multiplets plus the most comprehensive set of known/predicted isolated forbidden components to date. Moreover, a so far unreported series of pronounced forbidden He I components is detected in the optical-UV.

CARMENES: First Results from the CAHA 3.5m Telescope

NASA Astrophysics Data System (ADS)

Quirrenbach, Andreas; Consortium, CARMENES

2015-12-01

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) is a next-generation instrument currently undergoing commissioning at the 3.5m telescope at the Calar Alto Observatory. It has been developed by a consortium of eleven Spanish and German institutions (see also Quirrenbach et al. 2010; 2012; 2014). CARMENES will conduct a 600-night exoplanet survey targeting ~300 M dwarfs. An important and unique feature of the CARMENES instrument is that it consists of two separate échelle spectrographs, which together cover the wavelength range from 0.55 to 1.7 μm at a spectral resolution of R = 82,000. The spectrographs are fed by fibers from the Cassegrain focus of the telescope.The main scientific objective of the CARMENES project is to carry out a survey of late-type main sequence stars with the goal of detecting low-mass planets in their habitable zones (HZs). In the focus of the project are very cool stars later than spectral type M4 and moderately active stars. We aim at being able to detect a 2M⊕ planet in the HZ of an M5 star. A long-term radial velocity precision of 1ms-1 per measurement will permit to attain such goals. For stars later than M4 (M < 0.25M⊙), such precision will yield detections of super-Earths of 5M⊕ and smaller inside the entire width of the HZ. The CARMENES survey will thus provide a comprehensive overview of planetary systems around nearby Northern M dwarfs. By reaching into the realm of Earth-like planets, it will provide a treasure trove for follow-up studies probing their habitability.Quirrenbach, A., Amado, P.J., Mandel, H., et al. (2010). CARMENES: Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs. In Ground-based and airborne instrumentation for astronomy III. Eds. McLean, I.S., Ramsay, S.K., & Takami, H., SPIE 773513Quirrenbach, A., Amado, P.J., Seifert, W., et al. (2012). CARMENES. I: Instrument and survey overview. In Ground-based and airborne instrumentation for astronomy IV. Eds. McLean, I.S., Ramsay, S.K., & Takami, H., SPIE 84460RQuirrenbach, A., Amado, P.J., Caballero, J.A., et al. (2014). CARMENES instrument overview. In Ground-based and airborne instrumentation for astronomy V. Eds. Ramsay, S.K., McLean, I.S., & Takami, H., SPIE 91471F

Spectrographs and Large Telescopes: A Study of Instrumentation

NASA Astrophysics Data System (ADS)

Fica, Haley Diane; Crane, Jeffrey D.; Uomoto, Alan K.; Hare, Tyson

2017-01-01

It is a truth universally acknowledged, that a telescope in possession of a large aperture, must be in want of a high resolution spectrograph. Subsystems of these instruments require testing and upgrading to ensure that they can continue to be scientifically productive and usher in a new era of astronomical research. The Planet Finder Spectrograph (PFS) and Magellan Inamori Kyocera Echelle (MIKE), both on the Magellan II Clay telescope at Las Campanas Observatory, and the Giant Magellan Telescope (GMT) Consortium Large Earth Finder (G-CLEF) are examples of such instruments. Bluer flat field lamps were designed for PFS and MIKE to replace lamps no longer available in order to ensure continued, efficient functionality. These newly designed lamps will result in better flat fielding and calibration of data, and thus result in increased reduction of instrument noise. When it is built and installed in 2022, G-CLEF will be be fed by a tertiary mirror on the GMT. Stepper motors attached to the back of this mirror will be used to correct misalignments in the optical relay system. These motors were characterized to ensure that they function as expected to an accuracy of a few microns. These projects incorporate several key aspects of astronomical instrumentation: designing, building, and testing.

VizieR Online Data Catalog: Kepler-10 RV measurements by HARPS-N (Dumusque+, 2014)

NASA Astrophysics Data System (ADS)

Dumusque, X.; Bonomo, A. S.; Haywood, R. D.; Malavolta, L.; Segransan, D.; Buchhave, L. A.; Collier, Cameron A.; Latham, D. W.; Molinari, E.; Pepe, F.; Udry, S.; Charbonneau, D.; Cosentino, R.; Dressing, C. D.; Figueira, P.; Fiorenzano, A. F. M.; Gettel, S.; Harutyunyan, A.; Horne, K.; Lopez-Morales, M.; Lovis, C.; Mayor, M.; Micela, G.; Motalebi, F.; Nascimbeni, V.; Phillips, D. F.; Piotto, G.; Pollacco, D.; Queloz, D.; Rice, K.; Sasselov, D.; Sozzetti, A.; Szentgyorgyi, A.; Watson, C.

2017-03-01

We monitored the RV variation of Kepler-10 with the HARPS-N spectrograph installed on the 3.57-m Telescopio Nazionale Galileo at the Spanish Observatorio del Roque de los Muchachos, La Palma Island, Spain (Cosentino et al. 2012SPIE.8446E..1VC). This instrument is an updated version of the original HARPS planet hunter installed on the 3.6-m telescope at the European Southern Observatory on La Silla, Chile (Mayor et al. 2003Msngr.114...20M). Just like its older brother, the HARPS-N instrument is an ultra-stable fiber-fed high-resolution (R = 115,000) optical echelle spectrograph optimized for the measurement of very precise RVs. The use of a more modern monolithic 4kx4k CCD enclosed in a more temperature stable cryostat, and the use of octagonal fibers for a better scrambling of the incoming light fed into the spectrograph should improve the precision of the instrument compared to HARPS. Scientific operations began at HARPS-N in 2012 August. Over the first two observing seasons, we obtained 157 RV measurements of Kepler-10. Four observations that were obtained during bad weather conditions had very low signal to noise (S/N, <10) and were rejected. (1 data file).

MIRADAS control system

NASA Astrophysics Data System (ADS)

Rosich Minguell, Josefina; Garzón Lopez, Francisco

2012-09-01

The Mid-resolution InfRAreD Astronomical Spectrograph (MIRADAS, a near-infrared multi-object echelle spectrograph operating at spectral resolution R=20,000 over the 1-2.5μm bandpass) was selected in 2010 by the Gran Telescopio Canarias (GTC) partnership as the next-generation near-infrared spectrograph for the world's largest optical/infrared telescope, and is being developed by an international consortium. The MIRADAS consortium includes the University of Florida, Universidad de Barcelona, Universidad Complutense de Madrid, Instituto de Astrofísica de Canarias, Institut de Física d'Altes Energies, Institut d'Estudis Espacials de Catalunya and Universidad Nacional Autónoma de México. This paper shows an overview of the MIRADAS control software, which follows the standards defined by the telescope to permit the integration of this software on the GTC Control System (GCS). The MIRADAS Control System is based on a distributed architecture according to a component model where every subsystem is selfcontained. The GCS is a distributed environment written in object oriented C++, which runs components in different computers, using CORBA middleware for communications. Each MIRADAS observing mode, including engineering, monitoring and calibration modes, will have its own predefined sequence, which are executed in the GCS Sequencer. These sequences will have the ability of communicating with other telescope subsystems.

Using CeSiC for UV spectrographs for the WSO/UV

NASA Astrophysics Data System (ADS)

Reutlinger, A.; Gál, C.; Brandt, C.; Haberler, P.; Zuknik, K.-H.; Sedlmaier, T.; Shustov, B.; Sachkov, M.; Moisheev, A.; Kappelmann, N.; Barnstedt, J.; Werner, K.

2017-11-01

The World Space Observatory Ultraviolet (WSO/UV) is a multi-national project lead by the Russian Federal Space Agency (Roscosmos) with the objective of high performance observations in the ultraviolet range. The 1.7 m WSO/UV telescope feeds UV spectrometers and UV imagers. The UV spectrometers comprise two high resolution Echelle spectrographs for the 100 - 170 nm and 170 - 300 nm wavelength range and a long slit spectrograph for the 100 - 300 nm band. All three spectrometers represent individual instruments that are assembled and aligned separately. In order to save mass while maintaining high stiffness, the instruments are combined to a monoblock. Cesic has been selected to reduce CTE related distortions of the instruments. In contrast to aluminium, the stable structure of Cesic is significantly less sensitive to thermal gradients. No further mechanism for focus correction with high functional, technical and operational complexity and dedicated System costs are necessary. Using Cesic also relaxes the thermal control requirements of +/-5°C, which represents a considerable cost driver for the S/C design. The WUVS instrument is currently studied in the context of a phase B2 study by Kayser-Threde GmbH including a Structural Thermal Model (STM) for verification of thermal and mechanical loads, stability due to thermal distortions and Cesic manufacturing feasibility.

The STIS MAMA status: Current detector performance

NASA Technical Reports Server (NTRS)

Danks, A. C.; Joseph, C.; Bybee, R.; Argebright, V.; Abraham, J.; Kimble, R.; Woodgate, B.

1992-01-01

The STIS (Space Telescope Imaging Spectrograph) is a second generation Hubble instrument scheduled to fly in 1997. Through a variety of modes, the instrument will provide spectral resolutions from R approximately 50 in the objective spectroscopy mode to 100,000 in the high resolution echelle mode in the wavelength region from 115 to 1000 nm. In the UV the instrument employs two MAMA (Multimode Anode Microchannel plate Arrays) 1024 by 1024 pixel detectors, which provide high DQE (Detective Quantum Efficiency), and good dynamic range and resolution. The current progress and performance of these detectors are reported, illustrating that the technology is mature and that the performance is very close to flight requirements.

VizieR Online Data Catalog: NiI transition probability measurements (Wood+, 2014)

NASA Astrophysics Data System (ADS)

Wood, M. P.; Lawler, J. E.; Sneden, C.; Cowan, J. J.

2014-04-01

As in much of our previous branching fraction work, this NiI branching fraction study makes use of archived FTS data from both the 1.0m Fourier Transform Spectrometer (FTS) previously at the National Solar Observatory (NSO) on Kitt Peak and the Chelsea Instruments FT500 UV FTS at Lund University in Sweden. Table 1 lists the 37 FTS spectra used in our NiI branching fraction study. All NSO spectra, raw interferograms, and header files are available in the NSO electronic archives. The 80 CCD frames of spectra from commercial Ni HCD lamps of the echelle spectrograph are listed in Table 2. (6 data files).

Manganese Abundances in the Stars with Metallicities -1 <[Fe/H]< +0.3

NASA Astrophysics Data System (ADS)

Mishenina, T.; Gorbaneva, T.; Pignatari, M.; Thielemann, F.-K.; Korotin, S.

2018-01-01

We estimate the Mn abundances in the atmospheres of 247 F-G-K-type dwarf stars belonging to the thin and thick disk populations in the metallicity range -1 < [Fe/H] < +0.3. The observations were conducted using the 1.93 m telescope at Observatoire de Haute-Provence (OHP, France) equipped with the echelle type spectrographs ELODIE and SOPHIE. The abundances were derived under the LTE approximation; the synthetic spectrum for the Mn lines was computed accounting for the hyperfine structure. Starting from the results obtained, we discuss the evolution of the [Mn/Fe] ratio with respect to [Fe/H] in the galactic disk.

Waveguide image-slicers for ultrahigh resolution spectroscopy

NASA Astrophysics Data System (ADS)

Beckert, Erik; Strassmeier, Klaus G.; Woche, Manfred; Eberhardt, Ramona; Tünnermann, Andreas; Andersen, Michael

2008-07-01

Waveguide image-slicer prototypes with resolutions up to 310.000 for the fiber fed PEPSI echelle spectrograph at the LBT and single waveguide thicknesses of down to 30 μm have been manufactured. The waveguides were macroscopically prepared, stacked up to an order of 7 and thinned back to square stack cross sections. A high filling ratio was achieved by realizing homogenous adhesive gaps of 4.6 μm, using index matching adhesives for TIR within the waveguides. The image-slicer stacks can be used in immersion mode and are miniaturized to be implemented in a set of four, measurements indicate an overall efficiency of above 80% for them.

Carbon and oxygen abundances from recombination lines in low-metallicity star-forming galaxies. Implications for chemical evolution

NASA Astrophysics Data System (ADS)

Esteban, C.; García-Rojas, J.; Carigi, L.; Peimbert, M.; Bresolin, F.; López-Sánchez, A. R.; Mesa-Delgado, A.

2014-09-01

We present deep echelle spectrophotometry of the brightest emission-line knots of the star-forming galaxies He 2-10, Mrk 1271, NGC 3125, NGC 5408, POX 4, SDSS J1253-0312, Tol 1457-262, Tol 1924-416 and the H II region Hubble V in the Local Group dwarf irregular galaxy NGC 6822. The data have been taken with the Very Large Telescope Ultraviolet-Visual Echelle Spectrograph in the 3100-10420 Å range. We determine electron densities and temperatures of the ionized gas from several emission-line intensity ratios for all the objects. We derive the ionic abundances of C2+ and/or O2+ from faint pure recombination lines in several of the objects, permitting to derive their C/H and C/O ratios. We have explored the chemical evolution at low metallicities analysing the C/O versus O/H, C/O versus N/O and C/N versus O/H relations for Galactic and extragalactic H II regions and comparing with results for Galactic halo stars and damped Lyα systems. We find that H II regions in star-forming dwarf galaxies occupy a different locus in the C/O versus O/H diagram than those belonging to the inner discs of spiral galaxies, indicating their different chemical evolution histories, and that the bulk of C in the most metal-poor extragalactic H II regions should have the same origin than in halo stars. The comparison between the C/O ratios in H II regions and in stars of the Galactic thick and thin discs seems to give arguments to support the merging scenario for the origin of the Galactic thick disc. Finally, we find an apparent coupling between C and N enrichment at the usual metallicities determined for H II regions and that this coupling breaks in very low metallicity objects.

WISDOM: the WIYN spectrograph for Doppler monitoring: a NASA-NSF concept for an extreme precision radial velocity instrument in support of TESS

NASA Astrophysics Data System (ADS)

Fżrész, Gábor; Simcoe, Robert; Barnes, Stuart I.; Buchhave, Lars A.; Egan, Mark; Foster, Rick; Hellickson, Tim; Malonis, Andrew; Phillips, David; Shectman, Stephen; Walsworth, Ronald; Winn, Josh; Woods, Deborah

2016-08-01

The Kepler mission highlighted that precision radial velocity (PRV) follow-up is a real bottleneck in supporting transiting exoplanet surveys. The limited availability of PRV instruments, and the desire to break the "1 m/s" precision barrier, prompted the formation of a NASA-NSF collaboration `NN-EXPLORE' to call for proposals designing a new Extreme Precision Doppler Spectrograph (EPDS). By securing a significant fraction of telescope time on the 3.5m WIYN at Kitt Peak, and aiming for unprecedented long-term precision, the EPDS instrument will provide a unique tool for U.S. astronomers in characterizing exoplanet candidates identified by TESS. One of the two funded instrument concept studies is led by the Massachusetts Institute of Technology, in consortium with Lincoln Laboratories, Harvard-Smithsonian Center for Astrophysics and the Carnegie Observatories. This paper describes the instrument concept WISDOM (WIYN Spectrograph for DOppler Monitoring) prepared by this team. WISDOM is a fiber fed, environmentally controlled, high resolution (R=110k), asymmetric white-pupil echelle spectrograph, covering a wide 380-1300nm wavelength region. Its R4 and R6 echelle gratings provide the main dispersion, symmetrically mounted on either side of a vertically aligned, vacuum-enclosed carbon fiber optical bench. Each grating feeds two cameras and thus the resulting wavelength range per camera is narrow enough that the VPHG cross-dispersers and employed anti-reflection coatings are highly efficient. The instrument operates near room temperature, and so thermal background for the near-infrared arm is mitigated by thermal blocking filters and a short (1.7μm) cutoff HgCdTe detector. To achieve high resolution while maintaining small overall instrument size (100/125mm beam diameter), imposed by the limited available space within the observatory building, we chose to slice the telescope pupil 6 ways before coupling light into fibers. An atmospheric dispersion corrector and fast tip-tilt system assures maximal light gathering within the 1.2″ entrance aperture. The six octagonal fibers corresponding to each slice of the pupil employ ball-lens double scramblers to stabilize the near- and far-fields. Three apiece are coupled into each of two rectangular fibers, to mitigate modal nose and present a rectilinear illumination pattern at the spectrograph's slit plane. Wavelength solutions are derived from ThAr lamps and an extremely wide coverage dual-channel laser frequency comb. Data is reduced on the fly for evaluation by a custom pipeline, while daily archives and extended scope data reduction products are stored on NExScI servers, also managing archives and access privileges for GTO and GO programs. Note: individual papers, submitted along this main paper, describe the details of subsystems such as the optical design (Barnes et al., 9908-247), the fiber link design (Fűrész et al., 9908-281), and the pupil slicer (Egan et al., 9912-183).

Open source pipeline for ESPaDOnS reduction and analysis

NASA Astrophysics Data System (ADS)

Martioli, Eder; Teeple, Doug; Manset, Nadine; Devost, Daniel; Withington, Kanoa; Venne, Andre; Tannock, Megan

2012-09-01

OPERA is a Canada-France-Hawaii Telescope (CFHT) open source collaborative software project currently under development for an ESPaDOnS echelle spectro-polarimetric image reduction pipeline. OPERA is designed to be fully automated, performing calibrations and reduction, producing one-dimensional intensity and polarimetric spectra. The calibrations are performed on two-dimensional images. Spectra are extracted using an optimal extraction algorithm. While primarily designed for CFHT ESPaDOnS data, the pipeline is being written to be extensible to other echelle spectrographs. A primary design goal is to make use of fast, modern object-oriented technologies. Processing is controlled by a harness, which manages a set of processing modules, that make use of a collection of native OPERA software libraries and standard external software libraries. The harness and modules are completely parametrized by site configuration and instrument parameters. The software is open- ended, permitting users of OPERA to extend the pipeline capabilities. All these features have been designed to provide a portable infrastructure that facilitates collaborative development, code re-usability and extensibility. OPERA is free software with support for both GNU/Linux and MacOSX platforms. The pipeline is hosted on SourceForge under the name "opera-pipeline".

VizieR Online Data Catalog: Line list for stellar chemical abundances (Bedell+, 2014)

NASA Astrophysics Data System (ADS)

Bedell, M.; Melendez, J.; Bean, J. L.; Ramirez, I.; Leite, P.; Asplund, M.

2017-05-01

The five solar spectra used in this analysis were obtained with very high resolution and signal-to-noise ratios (S/Ns) characteristic of data used in past stellar abundance analyses. Two spectra were taken with the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) instrument (Donati 2003, Solar Polarization (ASP Conf. Ser. 307), ed. J. Trujillo-Bueno & J. Sanchez Almeida (San Francisco, CA: ASP), 41) at the 3.6 m Canada-France-Hawaii Telescope on the night of 2013 March 4. The asteroids Ceres and Vesta were each observed in "star only" mode at a spectral resolving power R=81000. The remaining three solar spectra were taken with the Magellan Inamori Kyocera Echelle (MIKE) spectrograph (Bernstein et al. 2003SPIE.4841.1694B) at the 6.5 m Magellan Clay telescope. The asteroid Vesta was observed twice and Iris was observed once during three separate observing runs spanning January to September of 2011. All observations were carried out in MIKE's standard setup with the 0.35 arcsec width slit, giving a spectral resolving power of R=83000 on the blue CCD and 65000 on the red CCD. (1 data file).

The Cosmic Origins Spectrograph

NASA Astrophysics Data System (ADS)

Green, James C.; Froning, Cynthia S.; Osterman, Steve; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Linsky, Jeffrey L.; Savage, Blair D.; Sembach, Kenneth; Shull, J. Michael; Siegmund, Oswald H. W.; Snow, Theodore P.; Spencer, John; Stern, S. Alan; Stocke, John; Welsh, Barry; Béland, Stéphane; Burgh, Eric B.; Danforth, Charles; France, Kevin; Keeney, Brian; McPhate, Jason; Penton, Steven V.; Andrews, John; Brownsberger, Kenneth; Morse, Jon; Wilkinson, Erik

2012-01-01

The Cosmic Origins Spectrograph (COS) is a moderate-resolution spectrograph with unprecedented sensitivity that was installed into the Hubble Space Telescope (HST) in 2009 May, during HST Servicing Mission 4 (STS-125). We present the design philosophy and summarize the key characteristics of the instrument that will be of interest to potential observers. For faint targets, with flux F λ ≈ 1.0 × 10-14 erg cm-2 s-1 Å-1, COS can achieve comparable signal to noise (when compared to Space Telescope Imaging Spectrograph echelle modes) in 1%-2% of the observing time. This has led to a significant increase in the total data volume and data quality available to the community. For example, in the first 20 months of science operation (2009 September-2011 June) the cumulative redshift pathlength of extragalactic sight lines sampled by COS is nine times than sampled at moderate resolution in 19 previous years of Hubble observations. COS programs have observed 214 distinct lines of sight suitable for study of the intergalactic medium as of 2011 June. COS has measured, for the first time with high reliability, broad Lyα absorbers and Ne VIII in the intergalactic medium, and observed the He II reionization epoch along multiple sightlines. COS has detected the first CO emission and absorption in the UV spectra of low-mass circumstellar disks at the epoch of giant planet formation, and detected multiple ionization states of metals in extra-solar planetary atmospheres. In the coming years, COS will continue its census of intergalactic gas, probe galactic and cosmic structure, and explore physics in our solar system and Galaxy.

MINERVA-Red: A telescope dedicated to the discovery of planets orbiting the nearest low-mass stars

NASA Astrophysics Data System (ADS)

Sliski, David; Blake, Cullen; Johnson, John A.; Plavchan, Peter; Wittenmyer, Robert A.; Eastman, Jason D.; Barnes, Stuart; Baker, Ashley

2017-01-01

Results from Kepler and ground-based exoplanet surveys suggest that M-dwarfs host numerous small sized planets. Additionally, the discovery of the Earth-sized exoplanets orbiting Proxima Centauri and Trappist 1 demonstrate that these stars can host terrestrial planets in their habitable zones. Since low-mass stars are intrinsically faint at optical wavelengths, obtaining 1 m/s Doppler resolution to detect their planetary companions remains a challenge for instruments designed for sun-like stars. We describe a novel, high-cadence approach aimed at detecting and characterizing planets orbiting the closest low-mass stars to the Sun. MINERVA-Red is an echelle spectrograph optimized for the 'deep red', between 800 nm and 900 nm, where M-dwarfs are brightest. The spectrograph will be temperature controlled at 20C +/- 10mk and in a vacuum chamber which maintains a pressure below 0.01 mbar while using a Fabry-Perot etalon and U/Ne lamp for wavelength calibration. The spectrometer will operate with a robotic, 0.7-meter telescope at Mt. Hopkins, Arizona. We expect first light in 2017.

VizieR Online Data Catalog: Abundance of nine beta Cephei stars (Morel+, 2006)

NASA Astrophysics Data System (ADS)

Morel, T.; Butler, K.; Aerts, C.; Neiner, C.; Briquet, M.

2006-07-01

The equivalent widths (EWs) were measured on high-resolution spectra obtained with various echelle spectrographs (see Table 2 of paper for further details). Our EWs are systematically larger than the values quoted by Gies & Lambert (1992ApJ...387..673G) for the seven stars in common, but a similar trend is evident when comparing their values with previous measurements in the literature (see their Fig.4). This is likely to result from their use of Gaussian fitting instead of the direct integration used in our case. The same conclusion holds for the EWs of xi1 CMa presented by Hambly et al. (1996MNRAS.278..811H). (1 data file).

Adapting Low-Tech Gear to Exoplanet Discovery

NASA Astrophysics Data System (ADS)

Brown, Timothy M.

2014-01-01

The discovery of 51 Peg b by Mayor and Queloz revealed (among other things) that discovering extrasolar planets, though certainly difficult, was not as hard as professional astronomers had previously thought. At the same time, the astronomical equipment available to amateurs -- including optics, mountings, and CCD detectors -- had become quite capable. This combination of factors led to successful exoplanet programs that leaned heavily on amateur-grade hardware, seeking faster development times and lower costs than were possible for traditional no-compromises astronomical instrument programs. I will describe two of these in which I played a role: the AFOE (Advanced Fiber Optic Echelle) spectrograph, and the STellar Astrophysics and Research on Exoplanets (STARE) transit-search wide-field imager.

VizieR Online Data Catalog: 5yr radial velocity measurements of 19 Cepheids (Anderson+, 2016)

NASA Astrophysics Data System (ADS)

Anderson, R. I.; Casertano, S.; Riess, A. G.; Melis, C.; Holl, B.; Semaan, T.; Papics, P. I.; Blanco-Cuaresma, S.; Eyer, L.; Mowlavi, N.; Palaversa, L.; Roelens, M.

2016-11-01

We here present a detailed investigation of spectroscopic binarity of the 19 Cepheids for which HST/WFC3 spatial scan parallaxes are being recorded (Riess+ 2014ApJ...785..161R; Casertano+ 2016ApJ...825...11C). We have secured time-series observations from three different high-resolution echelle spectrographs: Coralie (R~60000) at the Swiss 1.2m Euler telescope located at La Silla Observatory, Chile; Hermes (R~85000) at the Flemish 1.2m Mercator telescope located at the Roque de los Muchachos Observatory on La Palma, Canary Islands, Spain; Hamilton (R~60000) at the 3m Shane telescope located at Lick Observatory, California, USA. (8 data files).

A study of H-alpha velocities in NGC 1499, NGC 7000, and IC 1318B/C

NASA Technical Reports Server (NTRS)

Fountain, W. F.; Gary, G. A.; Odell, C. R.

1983-01-01

Multiple slit echelle spectrograph observations of the H-alpha emission line are used to map the radial velocities of the California Nebula (NGC 1499), the North American Nebula complex (NGC 7000 and IC 5070), and IC 1318B/C. The California Nebula is singularly constant in velocity, considering its geometry. The North American Nebula complex reflects a very simple, classical dynamical picture. The expansion discovered earlier in IC 1318B/C is confirmed, detailed, and the model refined. The new data, along with that in earlier papers of this series, show that stellar wind acceleration and champagne flow mechanisms both play important roles in determining the evolution of H II regions.

Multi-resolution waveguide image slicer for the PEPSI instrument

NASA Astrophysics Data System (ADS)

Beckert, Erik; Strassmeier, Klaus G.; Woche, Manfred; Harnisch, Gerd; Hornaff, Marcel; Weber, Michael; Barnes, Stuart

2016-07-01

A waveguide image slicer with resolutions up to 270.000 (planned: 300.000) for the fiber fed PEPSI echelle spectrograph at the LBT and single waveguide thicknesses of down to 70 μm has been manufactured and tested. The waveguides were macroscopically prepared, stacked up to an order of seven and thinned back to square stack cross sections. A high filling ratio was achieved by realizing homogenous adhesive gaps of 3.6 μm, using index matching adhesives for TIR within the waveguides. The image slicer stacks are used in immersion mode and are miniaturized to enable implementation in a set of 2x8. The overall efficiency is between 92 % and 96 %.

PEPSI-feed: linking PEPSI to the Vatican Advanced Technology Telescope using a 450m long fibre

NASA Astrophysics Data System (ADS)

Sablowski, D. P.; Weber, M.; Woche, M.; Ilyin, I.; Järvinen, A.; Strassmeier, K. G.; Gabor, P.

2016-07-01

Limited observing time at large telescopes equipped with the most powerful spectrographs makes it almost impossible to gain long and well-sampled time-series observations. Ditto, high-time-resolution observations of bright targets with high signal-to-noise are rare. By pulling an optical fibre of 450m length from the Vatican Advanced Technology Telescope (VATT) to the Large Binocular Telescope (LBT) to connect the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) to the VATT, allows for ultra-high resolution time-series measurements of bright targets. This article presents the fibre-link in detail from the technical point-of-view, demonstrates its performance from first observations, and sketches current applications.

Massive Stars in the SDSS-IV/APOGEE SURVEY. I. OB Stars

NASA Astrophysics Data System (ADS)

Roman-Lopes, A.; Román-Zúñiga, C.; Tapia, Mauricio; Chojnowski, Drew; Gómez Maqueo Chew, Y.; García-Hernández, D. A.; Borissova, Jura; Minniti, Dante; Covey, Kevin R.; Longa-Peña, Penélope; Fernandez-Trincado, J. G.; Zamora, Olga; Nitschelm, Christian

2018-03-01

In this work, we make use of DR14 APOGEE spectroscopic data to study a sample of 92 known OB stars. We developed a near-infrared semi-empirical spectral classification method that was successfully used in case of four new exemplars, previously classified as later B-type stars. Our results agree well with those determined independently from ECHELLE optical spectra, being in line with the spectral types derived from the “canonical” MK blue optical system. This confirms that the APOGEE spectrograph can also be used as a powerful tool in surveys aiming to unveil and study a large number of moderately and highly obscured OB stars still hidden in the Galaxy.

ORAC-DR: One Pipeline for Multiple Telescopes

NASA Astrophysics Data System (ADS)

Cavanagh, B.; Hirst, P.; Jenness, T.; Economou, F.; Currie, M. J.; Todd, S.; Ryder, S. D.

ORAC-DR, a flexible and extensible data reduction pipeline, has been successfully used for real-time data reduction from UFTI and IRCAM (infrared cameras), CGS4 (near-infrared spectrometer), Michelle (mid-infrared imager and echelle spectrometer), at UKIRT; and SCUBA (sub-millimeter bolometer array) at JCMT. We have now added the infrared imaging spectrometers IRIS2 at the Anglo-Australian Telescope and UIST at UKIRT to the list of officially supported instruments. We also present initial integral field unit support for UIST, along with unofficial support for the imager and multi-object spectrograph GMOS at Gemini. This paper briefly describes features of the pipeline along with details of adopting ORAC-DR for other instruments on telescopes around the world.

High Resolution Spectroscopy in the Far UV: Observations of the Interstellar Medium by IMAPS on ORFEUS-SPAS

NASA Astrophysics Data System (ADS)

Jenkins, Edward B.; Reale, Michael A.; Zucchino, Paul M.; Sofia, Ulysses J.

1996-09-01

The Interstellar Medium Absorption Profile Spectrograph (IMAPS) is an objectivegrating, echelle spectrograph built to observe the spectra of bright, hot stars over the spectral region 950 1150Å, below the wavelength coverage of HST. This instrument has a high wavelength resolving power, making it especially well suited for studies of interstellar absorption lines. Following a series of sounding rocket flights in the 1980's, IMAPS flew on its first Shuttle-launched orbital mission in September 1993, as a partner in the ORFEUS-SPAS program sponsored by the US and German Space Agencies, NASA and DARA. On ORFEUS-SPAS, IMAPS spent one day of orbital time observing the spectra of 10 O- and early B-type stars. In addition to outlining how IMAPS works, we document some special problems that had an influence on the data, and we explain the specific steps in data reduction that were employed to overcome them. This discussion serves as a basic source of information for people who may use archival data from this flight, as well as those who are interested in some specific properties of the data that will be presented in forthcoming research papers. IMAPS is scheduled to fly once again on ORFEUS-SPAS in late 1996. On this flight, 50% of the observing time available for IMAPS and two other spectrographs on the mission will be available to guest observers.

CAFE: Calar Alto Fiber-fed Echelle spectrograph

NASA Astrophysics Data System (ADS)

Sánchez, S. F.; Aceituno, J.; Thiele, U.; Grupp, F.; Dreizler, S.; Bean, J.; Benitez, D.

2011-11-01

The Calar Alto Fiber-fed Echelle spectrograph (CAFE) is an instrument underconstruction at CAHA to replace FOCES, the high-resolution echellespectrograph at the 2.2 m telescope of the observatory. FOCES is a property ofthe Observatory of the Munich University, and it was recalled it from Calar Altoin 2009. The instrument comprised a substantial fraction of thetelescope time during its operational life-time, and it is due to that it wastaken the decision to build a replacement.CAFE shares its basic characteristics with those of FOCES. However, significantimprovements have been introduced in the original design, the quality of thematerials, and the overall stability of the system. In particular: (i) a newcalibration Iodine cell is foreseen to operate together with the standard ThArlamps; (ii) the optical quality of all the components has been selected to belambda/20, instead of the original lambda/10; (iii) an isolated room hasbeen selected to place the instrument, termalized and stabilized againstvibrations (extensive tests have been performed to grant the stability); (iv)most of the mobile parts in FOCES has been substituted by fixed elements, toincrease the stability of the system; and finally (v) a new more efficientCCD, with a smaller pixel has been acquired. It is expected that the overallefficiency and the quality of the data will be significantly improved withrespect to its precesor. In particular, CAFE is design and built to achieveresolutions of R ˜ 70000, which will be kept in the final acquired data,allowing it to compete with current operational extrasolar planets hunters.After two years of work all the components are in place. The instrument is nowfinally assembled, and we are performing the the first alignment tests. It isexpected that the commissioning on the laboratory will finish at the end of2010, followed by the commissioning on telescope along the first semester of2011. If everything goes well, we will offer the instrument in a shared-riskmode for the second semester of 2011.

The SLICE, CHESS, and SISTINE Ultraviolet Spectrographs: Rocket-Borne Instrumentation Supporting Future Astrophysics Missions

NASA Astrophysics Data System (ADS)

France, Kevin; Hoadley, Keri; Fleming, Brian T.; Kane, Robert; Nell, Nicholas; Beasley, Matthew; Green, James C.

2016-03-01

NASA’s suborbital program provides an opportunity to conduct unique science experiments above Earth’s atmosphere and is a pipeline for the technology and personnel essential to future space astrophysics, heliophysics, and atmospheric science missions. In this paper, we describe three astronomy payloads developed (or in development) by the Ultraviolet Rocket Group at the University of Colorado. These far-ultraviolet (UV) (100-160nm) spectrographic instruments are used to study a range of scientific topics, from gas in the interstellar medium (accessing diagnostics of material spanning five orders of magnitude in temperature in a single observation) to the energetic radiation environment of nearby exoplanetary systems. The three instruments, Suborbital Local Interstellar Cloud Experiment (SLICE), Colorado High-resolution Echelle Stellar Spectrograph (CHESS), and Suborbital Imaging Spectrograph for Transition region Irradiance from Nearby Exoplanet host stars (SISTINE) form a progression of instrument designs and component-level technology maturation. SLICE is a pathfinder instrument for the development of new data handling, storage, and telemetry techniques. CHESS and SISTINE are testbeds for technology and instrument design enabling high-resolution (R>105) point source spectroscopy and high throughput imaging spectroscopy, respectively, in support of future Explorer, Probe, and Flagship-class missions. The CHESS and SISTINE payloads support the development and flight testing of large-format photon-counting detectors and advanced optical coatings: NASA’s top two technology priorities for enabling a future flagship observatory (e.g. the LUVOIR Surveyor concept) that offers factors of ˜50-100 gain in UV spectroscopy capability over the Hubble Space Telescope. We present the design, component level laboratory characterization, and flight results for these instruments.

Updates on the Performance and Calibration of HST/STIS

NASA Astrophysics Data System (ADS)

Lockwood, Sean A.; Monroe, TalaWanda R.; Ogaz, Sara; Branton, Doug; Carlberg, Joleen K.; Debes, John H.; Jedrzejewski, Robert I.; Proffitt, Charles R.; Riley, Allyssa; Sohn, Sangmo Tony; Sonnentrucker, Paule; Walborn, Nolan R.; Welty, Daniel

2018-06-01

The Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) has been in orbit for 21 years and continues to produce high quality scientific results using a diverse complement of operating modes. These include spatially resolved spectroscopy in the UV and optical, high spatial resolution echelle spectroscopy in the UV, and solar-blind imaging in the UV. In addition, STIS possesses unique visible-light coronagraphic modes that keep the instrument at the forefront of exoplanet and debris-disk research. As the instrument's characteristics evolve over its lifetime, the instrument team at the Space Telescope Science Institute monitors its performance and works towards improving the quality of its data products. Here we present updates on the status of the STIS CCD and FUV & NUV MAMA detectors, as well as changes to the CalSTIS reduction pipeline. We also discuss progress toward the recalibration of the E140M/1425 echelle mode. The E140M grating blaze function shapes have changed since flux calibration was carried out following SM4, which limits the relative photometric flux accuracy of some spectral orders up to 5-10% at the edges. In Cycle 25 a special calibration program was executed to obtain updated sensitivity curves for the E140M/1425 setting.

THE SOLAR NEIGHBORHOOD. XXVI. AP Col: THE CLOSEST (8.4 pc) PRE-MAIN-SEQUENCE STAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riedel, Adric R.; Henry, Todd J.; Jao, Wei-Chun

2011-10-15

We present the results of a multi-technique investigation of the M4.5Ve flare star AP Col, which we discover to be the nearest pre-main-sequence star. These include astrometric data from the CTIO 0.9 m, from which we derive a proper motion of 342.0 {+-} 0.5 mas yr{sup -1}, a trigonometric parallax of 119.21 {+-} 0.98 mas (8.39 {+-} 0.07 pc), and photometry and photometric variability at optical wavelengths. We also provide spectroscopic data, including radial velocity (22.4 {+-} 0.3 km s{sup -1}), lithium equivalent width (EW) (0.28 {+-} 0.02 A), H{alpha} EW (-6.0 to -35 A), vsin i (11 {+-} 1more » km s{sup -1}), and gravity indicators from the Siding Spring 2.3 m WiFeS, Lick 3 m Hamilton echelle, and Keck-I HIRES echelle spectrographs. The combined observations demonstrate that AP Col is the closer of only two known systems within 10 pc of the Sun younger than 100 Myr. Given its space motion and apparent age of 12-50 Myr, AP Col is likely a member of the recently proposed {approx}40 Myr old Argus/IC 2391 Association.« less

The New Absolute Parameters of OU Gem - The Star of BY Dra Type

NASA Astrophysics Data System (ADS)

Mishenina, T. V.; Glazunova, L. V.; Soubiran, C.; Kovtyukh, V. V.

2010-12-01

The spectra of OU Gem were obtained with the fiber-fed echelle spectrograph SOPHIE at the 1.93-m telescope of the Observatoire de Haute- Provence (France). The temperatures of components of the system were defined and are equal to 5013 ± 15 K and 4486±50 K for primary (A) and secondary (B) components, accordingly. The rotation velocity of components are measured: for primary component it is equal to 5.1±1 km/s and 6.2 ± km/s for the secondary one. The definition of radial velocities of components by LSD profile method and redetermination of spectral orbital elements were carried out. New absolute parameters of components were obtained too.

VizieR Online Data Catalog: Kepler-10 chemical composition (Liu+, 2016)

NASA Astrophysics Data System (ADS)

Liu, F.; Yong, D.; Asplund, M.; Ramirez, I.; Melendez, J.; Gustafsson, B.; Howes, L. M.; Roederer, I. U.; Lambert, D. L.; Bensby, T.

2016-09-01

We obtained high resolution and high SNR spectra with the Canada-France-Hawaii Telescope (CFHT), the Hobby-Eberly Telescope (HET) and the Magellan Clay Telescope. We observed Kepler-10 with the Echelle SpectroPolarimetric Device for the Observation of Stars at the CFHT during 2013 June. The spectral revolving power is 68000 and the spectral range is 3800-8900Å. We also observed Kepler-10 with the High Resolution Spectrograph (HRS) on the HET at McDonald Observatory during 2011 May. A total integration time of 6.8h was needed to achieve SNR>350 per pixel. The spectrum has a spectral resolving power of 60000 and covers 4100-7800Å, with a gap of about 100Å around 6000Å. (4 data files).

The SONG prototype: Efficiency of a robotic telescope

NASA Astrophysics Data System (ADS)

Andersen, M. F.; Grundahl, F.; Beck, A. H.; Pallé, P.

2016-12-01

The Stellar Observations Network Group prototype telescope at the Teide Observatory has been operating in scientific mode since March 2014. The first year of observations has entirely been carried out using the high resolution echelle spectrograph. Several asteroseismic targets were selected for scientific and technical verification. A few bright subgiants and one red giant were chosen since the oscillations in these stars have large amplitudes and the periods long enough to easily be detected. These targets would also be used for evaluation of the instruments since long term observations of single targets would reveal potential problems. In this paper the performance of the first robotic SONG node is described to illustrate the efficiency and possibilities in having a robotic telescope.

HR8844: a new hot Am star?

NASA Astrophysics Data System (ADS)

Monier, R.; Gebran, M.; Royer, F.

2016-12-01

Using one archival high dispersion high quality spectrum of HR8844 (A0V) obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star is not a superficially normal A0V star as hitherto thought. The model atmosphere and spectrum synthesis modeling of the spectrum of HR8844 reveals large departures of its abundances from the solar composition. We report here on our first determinations of the elemental abundances of 41 elements in the atmosphere of HR8844. Most of the light elements are underabundant whereas the very heavy elements are overabundant in HR8844. This interesting new chemically peculiar star could be a hybrid object between the HgMn stars and the Am stars.

Laser continuum source atomic absorption spectroscopy: Measuring the ground state with nanosecond resolution in laser-induced plasmas

NASA Astrophysics Data System (ADS)

Merten, Jonathan; Johnson, Bruce

2018-01-01

A new dual-beam atomic absorption technique is applied to laser-induced plasmas. The technique uses an optical parametric oscillator pseudocontinuum, producing emission that is both wider than the absorption line profile, but narrow enough to allow the use of an echelle spectrograph without order sorting. The dual-beam-in space implementation makes the technique immune to nonspecific attenuation of the probe beam and the structure of the pseudocontinuum. The potential for plasma diagnostics is demonstrated with spatially and temporally resolved measurements of magnesium metastable and lithium ground state optical depths in a laser-induced plasma under reduced pressure conditions. The lithium measurements further demonstrate the technique's potential for isotope ratio measurements.

KiwiSpec - an advanced spectrograph for high resolution spectroscopy: optical design and variations

NASA Astrophysics Data System (ADS)

Barnes, Stuart I.; Gibson, Steve; Nield, Kathryn; Cochrane, Dave

2012-09-01

The KiwiSpec R4-100 is an advanced high resolution spectrograph developed by KiwiStar Optics, Industrial Research Ltd, New Zealand. The instrument is based around an R4 echelle grating and a 100mm collimated beam diameter. The optical design employs a highly asymmetric white pupil design, whereby the transfer collimator has a focal length only 1/3 that of the primary collimator. This allows the cross-dispersers (VPH gratings) and camera optics to be small and low cost while also ensuring a very compact instrument. The KiwiSpec instrument will be bre-fed and is designed to be contained in both thermal and/or vacuum enclosures. The instrument concept is highly exible in order to ensure that the same basic design can be used for a wide variety of science cases. Options include the possibility of splitting the wavelength coverage into 2 to 4 separate channels allowing each channel to be highly optimized for maximum eciency. CCDs ranging from smaller than 2K2K to larger than 4K4K can be accommodated. This allows good (3-4 pixel) sampling of resolving powers ranging from below 50,000 to greater than 100,000. Among the specic design options presented here will be a two-channel concept optimized for precision radial velocities, and a four-channel concept developed for the Gemini High- Resolution Optical Spectrograph (GHOST). The design and performance of a single-channel prototype will be presented elsewhere in these proceedings.

VizieR Online Data Catalog: Spectroscopy of EG And over roughly 14 years (Kenyon+, 2016)

NASA Astrophysics Data System (ADS)

Kenyon, S. J.; Garcia, M. R.

2016-08-01

From 1994 September to 2016 January, P. Berlind, M. Calkins, and other observers acquired 480 low-resolution optical spectra of EG And with FAST, a high throughput, slit spectrograph mounted at the Fred L. Whipple Observatory 1.5m telescope on Mount Hopkins, Arizona They used a 300g/mm grating blazed at 4750Å, a 3'' slit, and a thinned 512*2688 CCD. These spectra cover 3800-7500Å at a resolution of 6Å. The full wavelength solution is derived from calibration lamps acquired immediately after each exposure. The wavelength solution for each frame has a probable error of <~+/-0.5Å. Most of the resulting spectra have moderate signal-to-noise ratio, S/N >~15-30 per pixel. Prior to the start of the FAST observations, we obtained occasional optical spectrophotometric observations of EG And throughout 1982-1989 with the cooled dual-beam intensified Reticon scanner (IRS) mounted on the white spectrograph at the KPNO No. 1 and No. 2 90cm telescopes. Various remote observers acquired high-resolution spectroscopic observations of EG And with the echelle spectrographs and Reticon detectors on the 1.5m telescopes of the Fred L. Whipple Observatory on Mount Hopkins, Arizona and the Oak Ridge Observatory in Harvard, Massachusetts. These spectra cover a 44Å bandpass centered near 5190Å or 5200Å and have a resolution of roughly 12km/s. (1 data file).

Chemical study of the metal-rich globular cluster NGC 5927

NASA Astrophysics Data System (ADS)

Mura-Guzmán, A.; Villanova, S.; Muñoz, C.; Tang, B.

2018-03-01

Globular clusters (GCs) are natural laboratories where stellar and chemical evolution can be studied in detail. In addition, their chemical patterns and kinematics can tell us to which Galactic structure (disc, bulge, halo or extragalactic) the cluster belongs to. NGC 5927 is one of most metal-rich GCs in the Galaxy and its kinematics links it to the thick disc. We present abundance analysis based on high-resolution spectra of seven giant stars. The data were obtained using Fibre Large Array Multi Element Spectrograph/Ultraviolet Echelle Spectrograph (UVES) spectrograph mounted on UT2 telescope of the European Southern Observatory. The principal objective of this work is to perform a wide and detailed chemical abundance analysis of the cluster and look for possible Multiple Populations (MPs). We determined stellar parameters and measured 22 elements corresponding to light (Na, Al), alpha (O, Mg, Si, Ca, Ti), iron-peak (Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn), and heavy elements (Y, Zr, Ba, Ce, Nd, Eu). We found a mean iron content of [Fe/H] = -0.47 ± 0.02 (error on the mean). We confirm the existence of MPs in this GC with an O-Na anti-correlation, and moderate spread in Al abundances. We estimate a mean [α/Fe] = 0.25 ± 0.08. Iron-peak elements show no significant spread. The [Ba/Eu] ratios indicate a predominant contribution from SNeII for the formation of the cluster.

VizieR Online Data Catalog: Solar-type stars from SDSS-III MARVELS. VI. HD 87646 (Ma+, 2016)

NASA Astrophysics Data System (ADS)

Ma, B.; Ge, J.; Wolszczan, A.; Muterspaugh, M. W.; Lee, B.; Henry, G. W.; Schneider, D. P.; Martin, E. L.; Niedzielski, A.; Xie, J.; Fleming, S. W.; Thomas, N.; Williamson, M.; Zhu, Z.; Agol, E.; Bizyaev, D.; da Costa, L. N.; Jiang, P.; Fiorenzano, A. F. M.; Hernandez, J. I. G.; Guo, P.; Grieves, N.; Li, R.; Liu, J.; Mahadevan, S.; Mazeh, T.; Nguyen, D. C.; Paegert, M.; Sithajan, S.; Stassun, K.; Thirupathi, S.; van Eyken, J. C.; Wan, X.; Wang, J.; Wisniewski, J. P.; Zhao, B.; Zucker, S.

2016-11-01

We have obtained a total of 16 observations of HD87646 using the W.M. Keck Exoplanet Tracker (KeckET) from 2006 December to 2007 June. The radial velocities obtained are listed in Table1. The KeckET instrument was constructed in 2005 August-2006 February with support from the Keck Foundation. It was coupled with a wide field Sloan Digital Sky Survey telescope (SDSS) and used for the pilot Multi-Object APO RV Exoplanet Large-Area Survey (MARVELS). This is the sixth paper in this series, examining the low-mass companions around solar-type stars from the SDSS-III MARVELS survey (Wisniewski et al. 2012, Cat. J/AJ/143/107; Fleming et al. 2012AJ....144...72F; Ma et al. 2013AJ....145...20M; Jiang et al. 2013AJ....146...65J; De Lee et al. 2013AJ....145..155D). The KeckET instrument consists of eight subsystems-a multi-object fiber feed, an iodine cell, a fixed-delay interferometer system, a slit, a collimator, a grating, a camera, and a 4k*4k CCD detector. In addition, it contains four auxiliary subsystems: the interferometer control, an instrument calibration system, a photon flux monitoring system, and a thermal probe and control system. The instrument is fed with 60 fibers with 200μm core diameters, which are coupled to 180μm core diameter short fibers from the SDSS telescope, corresponding to 3arcsec on the sky at f/5. The resolving power for the spectrograph is R=5100, and the wavelength coverage is ~900Å, centered at 5400Å. KeckET has one spectrograph and one 4k*4k CCD camera that captures one of the two interferometer outputs, and has a 5.5% detection efficiency from the telescope to the detector without the iodine cell under the typical APO seeing conditions (~1.5arcsec seeing). The CCD camera records fringing spectra from 59 objects in a single exposure. Subsequent observations were performed using the Exoplanet Tracker (ET) instrument at Kitt Peak National Observatory (KPNO). Initial follow-up was performed in 2007 November. Additional data points were obtained at KPNO in 2008 January, February, and May. The integration time was 35-40 minutes in 2007 November and 20 minutes in 2008 January, February, and May. A total of 40 data points were obtained from 2007 November to 2008 May and are also listed in Table1. Follow-up observations of HD87646 were conducted with the fiber-fed High Resolution Spectrograph (HRS) of the Hobby Eberley telescope (HET). The observations were executed in queue scheduled mode and used a 2 arcsec fiber, with the HRS slit set, to yield a spectral resolution of R~60000. A total of 29 data points were obtained between 2007 December and 2008 March. The HRS spectra consisted of 46 echelle orders recorded on the blue CCD (407-592nm) and 24 orders on the red one (602-784nm). The spectral data used for RV measurements were extracted from the 17 orders (505-592nm) in which the I2 cell superimposed strong absorption lines. The radial velocities obtained are also provided in Table1. HD87646 was selected as an radial velocity survey target by the Multi-object APO RV Exoplanet Large-area Survey (MARVELS) preselection criterion. The star has been monitored at 23 epochs using the MARVELS instrument mounted on the SDSS 2.5m Telescope at APO between 2009 May and 2011 December. The MARVELS instrument is a fiber-fed dispersed fixed-delay interferometer instrument capable of observing 60 objects simultaneously and covers a wavelength range of 5000-5700Å with a resolution of R~12000. The final differential radial velocity products are included in the SDSS Data Release 12 (Alam et al. 2015ApJS..219...12A) and are presented in Table1. We have obtained additional observations of HD87646 with a fiber-fed echelle spectrograph situated at the 2m Automatic Spectroscopic Telescope (AST) in the Fairborn Observatory. Through 2011 June, the detector was a 2048*4096 SITe ST-002A CCD with 15μm pixels. The AST echelle spectrograph has 21 orders that cover the wavelength range of 4920-7100Å, and has an average resolution of 0.17Å. In the summer of 2011, the SITe CCD detector and dewar were replaced with a Fairchild 486 CCD having 4K*4K 15μm pixels, which required a new readout electronics package, and a new dewar with a Cryotiger refrigeration system. The echelle spectrograms that were obtained with this new detector have 48 orders, covering the wavelength range of 3800-8260Å. A total of 135 data points were obtained from 2009 March through 2013 October and are listed in Table1. (1 data file).

Visible and Near-Infrared Properties of Optical Fibers Coupled to the Pathfinder High-Resolution NIR Spectrograph

NASA Astrophysics Data System (ADS)

McCoy, K.; Ramsey, L.

2011-09-01

The Penn State Astronomy and Astrophysics Department’s Pathfinder instrument is a fiber-fed, warm-bench echelle spectrograph designed to explore technical issues that must be resolved in order to measure precise radial velocities that will allow the detection of exoplanets in the near-infrared (NIR). In May 2010, Pathfinder demonstrated 10-20 m/s radial-velocity precision in the NIR at the 9 meter Hobby-Eberly Telescope. To attain even higher precision, we are investigating the NIR properties of the optical fibers that transmit light from the telescope to Pathfinder. We conducted a series of modal noise tests with visible and NIR laser diodes on a 200 micron diameter, fused-silica, multimode optical fiber as the preliminary step in analyzing the degrading effects of modal noise on radial-velocity precision. We report these test results and comment on our future tests to reduce the negative effects of modal noise and focal ratio degradation (FRD). The lessons learned from this research and the Pathfinder prototype will be used in Pathfinder II, which will aim to achieve better than 5 m/s in the NIR.

VizieR Online Data Catalog: Discovery of 2 hot Jupiters KELT-14b & KELT-15b (Rodriguez+, 2016)

NASA Astrophysics Data System (ADS)

Rodriguez, J. E.; Colon, K. D.; Stassun, K. G.; Wright, D.; Cargile, P. A.; Bayliss, D.; Pepper, J.; Collins, K. A.; Kuhn, R. B.; Lund, M. B.; Siverd, R. J.; Zhou, G.; Gaudi, B. S.; Tinney, C. G.; Penev, K.; Tan, T. G.; Stockdale, C.; Curtis, I. A.; James, D.; Udry, S.; Segransan, D.; Bieryla, A.; Latham, D. W.; Beatty, T. G.; Eastman, J. D.; Myers, G.; Bartz, J.; Bento, J.; Jensen, E. L. N.; Oberst, T. E.; Stevens, D. J.

2018-04-01

Spectroscopic observations of KELT-14 and KELT-15 were carried out using the CYCLOPS2 fiber feed with the UCLES spectrograph instrument on the Anglo-Australian Telescope (AAT) over two observing runs: UT 2015 February 02-UT 2015 March 01 and UT 2015 May 6-UT 2015 May 13. The instrumental set-up and observing strategy for these observations closely follow that described in earlier CYCLOPS RV papers (Addison et al. 2013ApJ...774L...9A, 2014ApJ...792..112A). CORALIE is a fiber-fed echelle spectrograph (Queloz et al. 2001Msngr.105....1Q) attached to the Swiss 1.2 m Leonard Euler telescope at the ESO La Silla Observatory in Chile. It has a spectral resolution of R~60000, a wavelength range of 3900-6800 Å, and is able to measure radial velocities of bright stars to a precision of 3 m/s or better (Pepe et al. 2002, J/A+A/388/632). We obtained spectra at five epochs of KELT-15 from UT 2015 September 02 to UT 2015 September 14. (3 data files).

The Unseen Companion of HD 114762

NASA Astrophysics Data System (ADS)

Latham, David W.

2014-01-01

I have told the story of the discovery of the unseen companion of HD114762 (Latham et al. 1989, Nature, 389, 38-40) in a recent publication (Latham 2012, New Astronomy Reviews 56, 16-18). The discovery was enabled by a happy combination of some thinking outside the box by Tsevi Mazeh at Tel Aviv University and the development of new technology for measuring stellar spectra at the Harvard-Smithsonian Center for Astrophysics. Tsevi's unconventional idea was that giant exoplanets might be found much closer to their host stars than Jupiter and Saturn are to the Sun, well inside the snow line. Our instrument was a high-resolution echelle spectrograph optimized for measuring radial velocities of stars similar to the Sun. The key technological developments were an intensified Reticon photon-counting detector under computer control combined with sophisticated analysis of the digital spectra. The detector signal-processing electronics eliminated persistence, which had plagued other intensified systems. This allowed bright Th-Ar calibration exposures before and after every stellar observation, which in turn enabled careful correction for spectrograph drifts. We built three of these systems for telescopes in Massachusetts and Arizona and christened them the "CfA Digital Speedometers". The discovery of HD 114762-b was serendipitous, but not accidental.

VizieR Online Data Catalog: Photmetry and spectroscopy of PMS stars in NGC 2264 (Lim+, 2016)

NASA Astrophysics Data System (ADS)

Lim, B.; Sung, H.; Kim, J. S.; Bessell, M. S.; Hwang, N.; Park, B.-G.

2018-04-01

Queue scheduled observations were carried out on 2015 April 1 and November 24 with the multi-object high resolution echelle spectrograph Hectochelle attached to the 6.5m telescope of the MMT observatory. The resolving power of the spectrograph (R~34,000) is high enough to detect the LiI λ6708 resonance doublet with little blending from adjacent metallic lines. The multi-object capability allowed us to simultaneously obtain 240 target and sky spectra in a single observation. The OB 26 filter transmits the wavelength range 6530-6715Å, and therefore the useful spectral features Hα λ6563 and HeI λ6678 could also be observed along with the LiI λ6708 line. The spectra of a total of 134 PMS stars were taken in two sets of exposure times -8 minutes x3 for bright stars (V<13.6mag) and 30 minutes x3 for fainter stars. Offset sky spectra were also obtained to correct for the contributions of locally variable nebula emission lines to the spectra of the faint stars. Calibration frames, such as dome flat and comparison spectra, were also acquired, just before and after the target exposure. (1 data file).

VizieR Online Data Catalog: Abundances in the local region. II. F, G, and K dwarfs (Luck+, 2017)

NASA Astrophysics Data System (ADS)

Luck, R. E.

2017-06-01

The McDonald Observatory 2.1m Telescope and Sandiford Cassegrain Echelle Spectrograph provided much of the observational data for this study. High-resolution spectra were obtained during numerous observing runs, from 1996 to 2010. The spectra cover a continuous wavelength range from about 484 to 700nm, with a resolving power of about 60000. The wavelength range used demands two separate observations--one centered at about 520nm, and the other at about 630nm. Typical S/N values per pixel for the spectra are more than 150. Spectra of 57 dwarfs were obtained using the Hobby-Eberly telescope and High-Resolution Spectrograph. The spectra have a resolution of 30000, spanning the wavelength range of 400 to 785nm. They also have very high signal-to-noise ratios, >300 per resolution element in numerous cases. The last set of spectra were obtained from the ELODIE Archive (Moultaka et al. 2004PASP..116..693M). These spectra are fully processed, including order co-addition, and have a continuous wavelength span of 400 to 680nm and a resolution of 42000. The ELODIE spectra utilized here all have S/N>75 per pixel. (6 data files).

High-Resolution Spectroscopy at the Wyoming Infrared Observatory: Setting TESS Science on FHiRE

NASA Astrophysics Data System (ADS)

Jang-Condell, Hannah; Pierce, Michael J.; Pilachowski, C. A.; Kobulnicky, Henry; McLane, Jacob N.

2018-01-01

The Fiber High Resolution Echelle (FHiRE) spectrograph is a new instrument designed for the 2.3-m Wyoming InfraRed Observatory (WIRO). With the construction of a vacuum chamber for FHiRE to stabilize the spectrograph and a temperature-stabilized Thorium-Argon lamp for precise velocity calibration, we will be able to achieve 1 m/s RV precision, making it an ideal instrument for finding exoplanets. Details of the design of FHiRE are presented in a companion poster (Pierce et al.). The construction of this instrument is well-timed with the planned 2018 launch of NASA's Transiting Exoplanet Survey Satellite (TESS) mission. TESS will require a great deal of follow-up spectroscopy to characterize potential exoplanet host stars as well as radial velocity measurements to confirm new exoplanets. WIRO is ideally suited to acquire the long-term, high-cadence observations that will be required to make progress in this frontier area of astrophysics. We will coordinate our efforts with the TESS Follow-up Observing Program (TFOP), specifically as part of the Recon Spectroscopy and Precise Radial Velocity Work sub-groups.This work is supported by a grant from NASA EPSCOR.

A Multi-object Exoplanet Detecting Technique

NASA Astrophysics Data System (ADS)

Zhang, K.

2011-05-01

Exoplanet exploration is not only a meaningful astronomical action, but also has a close relation with the extra-terrestrial life. High resolution echelle spectrograph is the key instrument for measuring stellar radial velocity (RV). But with higher precision, better environmental stability and higher cost are required. An improved technique of RV means invented by David J. Erskine in 1997, External Dispersed Interferometry (EDI), can increase the RV measuring precision by combining the moderate resolution spectrograph with a fixed-delay Michelson interferometer. LAMOST with large aperture and large field of view is equipped with 16 multi-object low resolution fiber spectrographs. And these spectrographs are capable to work in medium resolution mode (R=5{K}˜10{K}). LAMOST will be one of the most powerful exoplanet detecting systems over the world by introducing EDI technique. The EDI technique is a new technique for developing astronomical instrumentation in China. The operating theory of EDI was generally verified by a feasibility experiment done in 2009. And then a multi-object exoplanet survey system based on LAMOST spectrograph was proposed. According to this project, three important tasks have been done as follows: Firstly, a simulation of EDI operating theory contains the stellar spectrum model, interferometer transmission model, spectrograph mediation model and RV solution model. In order to meet the practical situation, two detecting modes, temporal and spatial phase-stepping methods, are separately simulated. The interference spectrum is analyzed with Fourier transform algorithm and a higher resolution conventional spectrum is resolved. Secondly, an EDI prototype is composed of a multi-object interferometer prototype and the LAMOST spectrograph. Some ideas are used in the design to reduce the effect of central obscuration, for example, modular structure and external/internal adjusting frames. Another feasibility experiment was done at Xinglong Station in 2010. A related spectrum reduction program and the instrumental stability were tested by obtaining some multi-object interference spectrum. Thirdly, studying the parameter optimization of fixed-delay Michelson interferometer is helpful to increase its inner thermal stability and reduce the external environmental requirement. Referring to Wide-angle Michelson Interferometer successfully used in Upper Atmospheric Wind field, a glass pair selecting scheme is given. By choosing a suitable glass pair of interference arms, the RV error can be stable as several hundred m\\cdots^{-1}\\cdot{dg}C^{-1}. Therefore, this work is helpful to deeply study EDI technique and speed up the development of multi-object exoplanet survey system. LAMOST will make a greater contribution to astronomy when the combination between its spectrographs and EDI technique comes true.

Sodium Laser Guide Star Technique, Spectroscopy and Imaging with Adaptive Optics

NASA Astrophysics Data System (ADS)

Ge, Jian

A sodium laser guide star (LGS) adaptive optics (AO) system developed at Stewart Observatory is to be used at the 6.5m MMT. Annual measurements at Kitt Peak show that the mean mesospheric sodium column density varies from ~2×109cm-2 (summer) to ~5×109cm-2 (winter). The sodium column density also varies by a factor of two during a one hour period. The first simultaneous measurements of sodium LGS brightness, sodium column density and laser power were obtained. The absolute sodium return for a continuous wave circularly polarized beam is 1.2([/pm]0.3)× 106 photons s-1m-2W-1 for the sodium column density of 3.7×109cm-2. Theoretical studies demonstrate that the 6.5m MMT LGS AO can provide Strehl ratios better than 0.15 and about 50% flux concentration within 0.2'' aperture for 1-5.5μm under median seeing. This correction will be available for the full sky. Better Strehl and higher flux concentration can be achieved with natural guide stars, but limited sky coverage. The AO corrected field-of-view is about 60''. The Arizona IR Imager and Echelle Spectrograph (ARIES) was designed to match the 6.5m MMT AO. Detection limits of more than 2 magnitude fainter can be reached with the AO over without the AO. A pre-ARIES wide field near-IR camera was designed, built and tested. The camera provides 1'' images in the near-IR over an 8.5 × 8.5arcmin2 field. The 10-σ detection limit with one minute exposures is 17.9 mag. in the K band. A prototype very high resolution cross-dispersed optical echelle spectrograph was designed and built to match the Starfire Optical Range 1.5m AO images. Interstellar KI 7698A absorption lines have been detected in the spectra of αCyg and ζPer. The spectral resolution is 250.000. About 300A wavelengths were covered in a single exposure. Total detection efficiency of 1% has been achieved. For the first time, a near-single-mode fiber with 10μm core size was applied to transmit the Mt. Wilson 100inch AO corrected beams to a spectrograph. The coupling efficiency of the fiber reached up to 70%. Spectra of αOri were recorded. The spectral resolution is 200,000. The total wavelength coverage is about 650A per exposure.

GIARPS: the unique VIS-NIR high precision radial velocity facility in this world

NASA Astrophysics Data System (ADS)

Claudi, R.; Benatti, S.; Carleo, I.; Ghedina, A.; Molinari, E.; Oliva, E.; Tozzi, A.; Baruffolo, A.; Cecconi, M.; Cosentino, R.; Fantinel, D.; Fini, L.; Ghinassi, F.; Gonzalez, M.; Gratton, R.; Guerra, J.; Harutyunyan, A.; Hernandez, N.; Iuzzolino, M.; Lodi, M.; Malavolta, L.; Maldonado, J.; Micela, G.; Sanna, N.; Sanjuan, J.; Scuderi, S.; Sozzetti, A.; Pérez Ventura, H.; Diaz Marcos, H.; Galli, A.; Gonzalez, C.; Riverol, L.; Riverol, C.

2016-08-01

GIARPS (GIAno and haRPS) is a project devoted to have on the same focal station of the Telescopio Nazionale Galileo (TNG) both the high resolution spectrographs HARPS-N (VIS) and GIANO (NIR) working simultaneously. This could be considered the first and unique worldwide instrument providing cross-dispersed echelle spectroscopy at a high resolution (R=115,000 in the visual and R=50,000 in the IR) and over in a wide spectral range (0.383 - 2.45 μm) in a single exposure. The science case is very broad, given the versatility of such an instrument and the large wavelength range. A number of outstanding science cases encompassing mainly extra-solar planet science starting from rocky planet search and hot Jupiters, atmosphere characterization can be considered. Furthermore both instrument can measure high precision radial velocity by means the simultaneous thorium technique (HARPS - N) and absorbing cell technique (GIANO) in a single exposure. Other science cases are also possible. Young stars and proto- planetary disks, cool stars and stellar populations, moving minor bodies in the solar system, bursting young stellar objects, cataclysmic variables and X-ray binary transients in our Galaxy, supernovae up to gamma-ray bursts in the very distant and young Universe, can take advantage of the unicity of this facility both in terms of contemporaneous wide wavelength range and high resolution spectroscopy.

On the spectroscopic nature of the cool evolved Am star HD151878

NASA Astrophysics Data System (ADS)

Freyhammer, L. M.; Elkin, V. G.; Kurtz, D. W.

2008-10-01

Recently, Tiwari, Chaubey & Pandey detected the bright component of the visual binary HD151878 to exhibit rapid photometric oscillations through a Johnson B filter with a period of 6min (2.78mHz) and a high, modulated amplitude up to 22mmag peak-to-peak, making this star by far the highest amplitude rapidly oscillating Ap (roAp) star known. As a new roAp star, HD151878 is of additional particular interest as a scarce example of the class in the northern sky, and only the second known case of an evolved roAp star - the other being HD116114. We used the FIbre-fed Echelle Spectrograph at the Nordic Optical Telescope to obtain high time-resolution spectra at high dispersion to attempt to verify the rapid oscillations. We show here that the star at this epoch is spectroscopically stable to rapid oscillations of no more than a few tens of ms-1. The high-resolution spectra furthermore show the star to be of type Am rather than Ap and we show the star lacks most of the known characteristics for roAp stars. We conclude that this is an Am star that does not pulsate with a 6-min period. The original discovery of pulsation is likely to be an instrumental artefact. Based on observations collected at the Nordic Optical Telescope as part of programme 36-418. E-mail: lfreyham@gmail.com

Lithium Abundance in M3 Red Giant

NASA Astrophysics Data System (ADS)

Givens, Rashad; Pilachowski, Catherine A.

2015-01-01

We present the abundance of lithium in the red giant star vZ 1050 (SK 291) in the globular cluster M3. A previous survey of giants in the cluster showed that like IV-101, vZ 1050 displays a prominent Li I 6707 Å feature. vZ 1050 lies on the blue side of the red giant branch about 1.3 magnitudes above the level of the horizontal branch, and may be an asymptotic giant branch star. A high resolution spectrum of M3 vZ1050 was obtained with the ARC 3.5m telescope and the ARC Echelle Spectrograph (ARCES). Atmospheric parameters were determined using Fe I and Fe II lines from the spectrum using the MOOG spectral analysis program, and the lithium abundance was determined using spectrum synthesis.

Improved Radial Velocity Precision with a Tunable Laser Calibrator

NASA Astrophysics Data System (ADS)

Cramer, Claire; Brown, S.; Dupree, A. K.; Lykke, K. R.; Smith, A.; Szentgyorgyi, A.

2010-01-01

We present radial velocities obtained using a novel laser-based wavelength calibration technique. We have built a prototype laser calibrator for the Hectochelle spectrograph at the MMT 6.5 m telescope. The Hectochelle is a high-dispersion, fiber-fed, multi-object spectrograph capable of recording up to 240 spectra simultaneously with a resolving power of 40000. The standard wavelength calibration method makes use of spectra from thorium-argon hollow cathode lamps shining directly onto the fibers. The difference in light path between calibration and science light as well as the uneven distribution of spectral lines are believed to introduce errors of up to several hundred m/s in the wavelength scale. Our tunable laser wavelength calibrator solves these problems. The laser is bright enough for use with a dome screen, allowing the calibration light path to better match the science light path. Further, the laser is tuned in regular steps across a spectral order to generate a calibration spectrum, creating a comb of evenly-spaced lines on the detector. Using the solar spectrum reflected from the atmosphere to record the same spectrum in every fiber, we show that laser wavelength calibration brings radial velocity uncertainties down below 100 m/s. We present these results as well as an application of tunable laser calibration to stellar radial velocities determined with the infrared Ca triplet in globular clusters M15 and NGC 7492. We also suggest how the tunable laser could be useful for other instruments, including single-object, cross-dispersed echelle spectrographs, and adapted for infrared spectroscopy.

KiwiSpec - an advanced spectrograph for high resolution spectroscopy: prototype design and performance

NASA Astrophysics Data System (ADS)

Gibson, Steve; Barnes, Stuart I.; Hearnshaw, John; Nield, Kathryn; Cochrane, Dave; Grobler, Deon

2012-09-01

A new advanced high resolution spectrograph has been developed by Kiwistar Optics of Industrial Research Ltd., New Zealand. The instrument, KiwiSpec R4-100, is bench-mounted, bre-fed, compact (0.75m by 1.5m footprint), and is well-suited for small to medium-sized telescopes. The instrument makes use of several advanced concepts in high resolution spectrograph design. The basic design follows the classical white pupil concept in an asymmetric implementation and employs an R4 echelle grating illuminated by a 100mm diameter collimated beam for primary dispersion. A volume phase holographic grating (VPH) based grism is used for cross-dispersion. The design also allows for up to four camera and detector channels to allow for extended wavelength coverage at high eciency. A single channel prototype of the instrument has been built and successfully tested with a 1m telescope. Targets included various spectrophotometric standard stars and several radial velocity standard stars to measure the instrument's light throughput and radial velocity capabilities. The prototype uses a 725 lines/mm VPH grism, an off-the-shelf camera objective, and a 2k×2k CCD. As such, it covers the wavelength range from 420nm to 660nm and has a resolving power of R ≍ 40,000. Spectrophotometric and precision radial velocity results from the on-sky testing period will be reported, as well as results of laboratory-based measurements. The optical design of KiwiSpec, and the various multi-channel design options, will be presented elsewhere in these proceedings.

The Cosmic Origins Spectrograph

NASA Technical Reports Server (NTRS)

Green, James C.; Froning, Cynthia S.; Osterman, Steve; Ebbets, Dennis; Heap, Sara H.; Leitherer, Claus; Linsky, Jeffrey L.; Savage, Blair D.; Sembach, Kenneth; Shull, J. Michael;

Design Considerations for the Installation of an Iodine (I2) Cell onto TRES

NASA Astrophysics Data System (ADS)

Garcia-Mejia, Juliana

2017-01-01

The radial velocity (RV) method utilizes the reflex motion of a target star to predict the presence of one or multiple exoplanets. However, the disparity in mass between planet and host star often results in RV oscillations below the precision of most modern spectrographs. Such is the case of TRES, the Tillinghast Reflector Echelle Spectrograph located in the Fred Lawrence Whipple Observatory in Mt. Hopkins, Arizona, with a radial velocity (RV) precision of ~ 20 m s-1, dominated by instrumental effects. Since 1992, the iodine cell technique, presented in Butler et al.(1992) has become widely used for the reduction of RV measurement errors. Here, we describe the beginning stages in the installation of one such cell onto TRES. After traveling to the telescope site to perform the first fitting of the iodine stage, I designed, built and fitted the first prototype of an improved thermal insulation system for the front end of the spectrograph, where the cell will be mounted. Here I present such a design, as well as a detailed description of the current state of the project. We expect the iodine cell to be fully functional in approximately 1 year. Once the cell is installed, we expect errors in radial velocity measurements to decrease by an order of magnitude from the aforementioned 20 m s-1. This increase in precision will come with an increase in stability of radial velocity measurements, allowing TRES to perform in-house spectroscopy of more nearby bright targets and high-cadence exoplanet follow-up.

First Light from the 4.3-meter Discovery Channel Telescope At Lowell Observatory

NASA Astrophysics Data System (ADS)

Hall, Jeffrey C.; Levine, S.

2013-01-01

Seven years after groundbreaking on July 12, 2005, the 4.3-meter Discovery Channel Telescope (DCT) is now complete and into commissioning. We obtained first light images in mid 2012 with a 4K x 4K CCD and have recently obtained our first images with the DCT's main camera, the 6K x 6K Large Monolithic Imager (LMI, see adjacent poster by Massey). We held a celebratory gala on July 21, 2012, in Flagstaff. The DCT's delivered image quality is regularly subarcsecond with near-uniform image quality across the FOV from zenith to >2 airmasses, although we have not fully commissioned the active optics system. We attribute this to the outstanding quality of the mirror figures, performed by the University of Arizona's College of Optical Sciences (for M1) and L3 Brashear (for M2). The instrument cube at the RC focus can accommodate four instruments plus the LMI. Designed and built at Lowell Observatory, the cube also contains the DCT's autoguider and wavefront sensor. First light instruments include the 4000 DeVeny spectrograph (the former KPNO White Spectrograph), a low-resolution, high-throughput IR spectrograph, and a higher-resolution IR spectrograph/imager being built by Goddard Space Flight Center in collaboration with the University of Maryland. We are seeking funding for long-slit and fiber-fed echelle spectrographs for higher resolution optical spectroscopy. The DCT can also be configured to host Nasmyth and prime focus instruments. Discovery Communications and its founder John Hendricks contributed $16M to the $53M cost of the telescope, in return for naming rights and first rights to public, educational use of images in their programming. Analysis of data and publication by astronomers in professional journals follows the same procedure as for any other major telescope facility. Discovery's first DCT feature, "Scanning the Skies," aired on September 9, 2012. Future outreach plans include initiating webcasts to classrooms via the Discovery Education networks, reaching 30-40M schoolchildren across the USA. The DCT partner consortium includes Boston University (in perpetuity), the University of Maryland, and the University of Toledo, all of whom have ongoing, long term access to the facility.

The Behavior of Warm Molecules in Planet-forming Disks and CHESS: a Pathfinder UV Spectrograph for the LUVOIR Surveyor

NASA Astrophysics Data System (ADS)

Hoadley, Keri; France, Kevin

2017-01-01

Understanding the evolution of gas over the lifetime of protoplanetary disks provides us with important clues about how planet formation mechanisms drive the diversity of exoplanetary systems observed to date. In the first part of my talk, I will discuss how we use emission line observations of molecular hydrogen (H2) in the far-ultraviolet (far-UV) with the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope to study the warm molecular regions (a < 10 AU) of planet-forming disks. We compare the observations with analytic disk models that produce synthetic H2 profiles, and we statistically determine the disk representations that best replicate the data. I will discuss the results of our comparisons and how the modeled radial distributions of H2 in the disk help provide important constraints on the effective density of gas left in the inner disk of protoplanetary disks at various disk evolutionary stages. Finally, I will talk about follow-up studies that look to connect the warm, UV-pumped molecular populations of the inner disk to thermally-excited molecules observed in similar regions of the disk in the near- to mid-IR.In the second part of my talk, I will discuss the observational requirements in the UV and IR band passes to gain further insights into the behavior of the warm, gaseous protoplanetary disk, focusing specifically on a spectrograph concept for the next-generation LUVOIR Surveyor. I will discuss a testbed instrument, the Colorado High-resolution Echelle Stellar Spectrograph (CHESS), built as a demonstration of one component of the LUVOIR spectrograph and new technological improvements to UV optical components for the next generation of near- to far-UV astrophysical observatories. CHESS is a far-UV sounding rocket experiment designed to probe the warm and cool atoms and molecules near sites of recent star formation in the local interstellar medium. I will talk about the science goals, design, research and development (R&D) components, and calibration of the CHESS instrument. I will end by presenting the initial data reduction and results of the flight observations taken during the second launch of CHESS.

Coordinated Ground- and Space-based Multispectral Campaign to Study Equatorial Spread-F Formation

NASA Astrophysics Data System (ADS)

Finn, S. C.; Geddes, G.; Aryal, S.; Stephan, A. W.; Budzien, S. A.; Duggirala, P. R.; Chakrabarti, S.; Valladares, C.

2016-12-01

We present a concept for a multispectral campaign using coordinated data from state-of-the-art instruments aboard the International Space Station (ISS) and multiple ground-based spectrometers and digisondes deployed at low-latitudes to study the formation and development of Equatorial Spread-F (ESF). This extended observational campaign utilizes ultraviolet, visible, and radio measurements to develop a predictive capability for ESF and to study the coupling of the ionosphere-thermosphere (I-T) system during geomagnetically quiet and disturbed times. The ground-based instruments will be deployed in carefully chosen locations in the American and Indian sectors while the space-based data will provide global coverage spanning all local times and longitudes within ±51° geographic latitudes. The campaign, over an extended period covering a range of geophysical conditions, will provide the extensive data base necessary to address the important science questions. The space-based instrument suite consists of the Limb-imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES) and the GPS Radio Occultation and Ultraviolet Photometry-Colocated (GROUP-C) instruments, scheduled to launch to the ISS in November 2016. LITES is a compact imaging spectrograph for remote sensing of the upper atmosphere and ionosphere from 60 to 140nm and GROUP-C has a nadir-viewing FUV photometer. The ground-based instruments to be deployed for this campaign are three high-resolution imaging spectrographs capable of continuous round-the-clock airglow observations: Multiwavelength Imaging Spectrograph using Echelle grating (MISE) in India and two High Throughput and Multi-slit Imaging Spectrographs (HiT&MIS) to be deployed in Colombia and Argentina, the Low-Latitude Ionosphere Sensor Network (LISN), and the Global Ionospheric Radio Observatory (GIRO) digisondes network. We present data from the ground-based instruments, initial results from the LITES and GROUP-C instruments on-orbit, and modeling and analysis methods for the campaign. This work was supported by NSF 1315354 and 1145166, and ONR N00014-13-1-0266 grants. LITES and GROUP-C are part of the STP-H5 Payload, integrated and flown under the direction of the DoD Space Test Program.

Infrared Spectroscopy of Disilicon-Carbide Si_2C

NASA Astrophysics Data System (ADS)

Witsch, Daniel; Lutter, Volker; Fuchs, Guido W.; Gauss, Jürgen; Giesen, Thomas

2017-06-01

Small silicon and carbon containing molecules are thought to be important building blocks of interstellar grains. Some of them have been detected in circumstellar environments of late-type stars by means of rotational spectroscopy e.g., SiC, SiC_2, Si_2C, c-SiC_3, SiC_4, while centro-symmetric species, e.g., C_3, C_4, C_5, Si_2C_2, Si_2C_3, can only be detected by vibrational transitions, mainly in the infrared. In view of a new generation of high resolution infrared telescope instruments, e.g., EXES (Echelon-Cross-Echelle Spectrograph) onboard SOFIA (Observatory for Infrared Astronomy) and TEXES (Texas Echelon Cross Echelle Spectrograph) at the Gemini-North observatory, accurate laboratory data of small silicon-carbides in the infrared region are of high demand. In this talk we present first laboratory data of the Si_2C asymmetric stretching mode at 1200 cm^{-1}. A pulsed Nd:YAG-laser is used to vaporize a solid target of silicon exposed to a dilute sample of methane in helium buffer gas. Si_2C is formed in an adiabatic expansion of a supersonic jet and radiation of a quantum cascade laser is used to record rotationally resolved spectra. To date, 160 ro-vibrational lines and have been assigned to the asymmetric stretching vibration of Si_2C, and derived molecular parameters are in excellent agreement with ab initio calculations. In our global fit analysis recently published microwave laboratory data (McCarthy et al. 2015) and astronomical data (Cernicharo et al. 2015) were taken into account. Our new results allow for the identification of Si_2C by means of high resolution infrared astronomy towards the warm background of carbon-rich stars. McCarthy M.C., Baraban J.H., Changala P.B., Stanton J.F., Martin-Drumel M.A, Thorwirth S., et al., J. Chem. Phys. Lett. 6, 2107-2111 (2015). Cernicharo J., McCarthy M.C., Gottlieb C.A., Agundez M., Velilla Prieto L., Baraban J.H., et al. Astrophys. J. Lett. 806,L3 (2015).

An Externally Dispersed Interferometer for Sensitive Doppler Extrasolar Planet Searches

NASA Astrophysics Data System (ADS)

Ge, Jian; Erskine, David J.; Rushford, Mike

2002-09-01

A new kind of instrument for sensitive Doppler extrasolar planet searches, called an externally dispersed interferometer, is described in this paper. It is a combination of an optical Michelson-type interferometer and an intermediate-resolution grating spectrometer. The interferometer measures Doppler radial velocity (RV) variations of starlight through the phase shifts of moiré fringes, created by multiplication of the interferometer fringes with stellar absorption lines. The intermediate-resolution spectrograph disperses the moiré fringes into thousands of parallel-wavelength channels. This increases the instrument bandwidth and fringe visibility by preventing fringe cross-talk between neighboring spectral lines. This results in a net increase in the signal-to-noise ratio over an interferometer used alone with broadband light. Compared to current echelle spectrometers for extrasolar planet searches, this instrument offers two unique instrument properties: a simple, stable, well-defined sinusoidal instrument response function (point-spread function) and magnification of Doppler motion through moiré fringe techniques. Since instrument noise is chiefly limited by the ability to characterize the instrument response, this new technique provides unprecedented low instrumental noise in an economical compact apparatus, enabling higher precision for Doppler RV measurements. In practice, the moiré magnification can be 5-10 times depending on the interferometer comb angle. This instrument has better sensitivity for smaller Doppler shifts than echelle spectrometers. The instrument can be designed with much lower spectral resolving power without losing Doppler sensitivity and optimized for higher throughput than echelle spectrometers to allow a potential survey for planets around fainter stars than current magnitude limits. Lab-based experiments with a prototype instrument with a spectral resolution of R~20,000 demonstrated ~0.7 m s-1 precision for short-term RV measurements. A fiber-fed version of the prototype with R~5600 was tested with starlight at the Lick 1 m telescope and demonstrated ~7 m s-1 RV precision at 340 Å bandwidth. The increased velocity noise is attributed to the lower spectral resolution, lower fringe visibility, and uncontrolled instrument environment.

Performance of the Space Telescope Imaging Spectrograph after SM4

NASA Technical Reports Server (NTRS)

Proffitt, Charles R.; Alosi, A.; Bohlin, R. C.; Bostroen, K. A.; Cox, C. R.; Diaz, R. I.; Dixon, W. V.; Goudfrooij, P.; Hodge, P.; Kaiser, M. E.;

Interstellar Medium Absorption Profile Spectrograph (IMAPS)

NASA Technical Reports Server (NTRS)

Jenkins, E. B.

1985-01-01

The design and fabrication of an objective-grating echelle spectrograph to fly on sounding rockets and record spectra of stars from approximately 920 to 1120A with a resolving power lambda/delta lambda = 200,000 is discussed. The scientific purpose of the program is to observe, with ten times better velocity resolution than before, the plentiful absorption lines in this spectral region produced by atoms, ions and molecules in the interstellar medium. In addition, an important technical goal is to develop and flight-quality a new ultraviolet, photon-counting image sensor which has a windowless, opaque photocathode and a CCD bombarded directly by the accelerated photoelectrons. Except for some initial difficulties with the performance of CCDs, the development of the payload instrument is relatively straightforward and our overall design goals are satisfied. The first flight occurred in late 1984, but no data were obtained because of an inrush of air degraded the instrument's vacuum and caused the detector's high voltage to arc. A second flight in early 1985 was a complete success and obtained a spectrum of pi Sco. Data from this mission are currently being reduced; quick-look versions of the spectra indicate that excellent results will be obtained. Currently, the payload is being reconfigured to fly on a Spartan mission in 1988.

Lithium abundance in a sample of solar-like stars

NASA Astrophysics Data System (ADS)

López-Valdivia, R.; Hernández-Águila, J. B.; Bertone, E.; Chávez, M.; Cruz-Saenz de Miera, F.; Amazo-Gómez, E. M.

2015-08-01

We report on the determination of the lithium abundance [A(Li)] of 52 solar-like stars. For 41 objects the A(Li) here presented corresponds to the first measurement. We have measured the equivalent widths of the 6708 Å lithium feature in high-resolution spectroscopic images (R ˜ 80 000), obtained at the Observatorio Astrofísico Guillermo Haro (Sonora, Mexico), as part of the first scientific observations of the revitalized Lunar and Planetary Laboratory (LPL) Echelle Spectrograph, now known as the Cananea High-resolution Spectrograph (CanHiS). Lithium abundances were derived with the Fortran code MOOG, using as fundamental input a set of atmospheric parameters recently obtained by our group. With the help of an additional small sample with previous A(Li) determinations, we demonstrate that our lithium abundances are in agreement, to within uncertainties, with other works. Two target objects stand out from the rest of the sample. The star BD+47 3218 (Teff = 6050 ± 52 K, A(Li) = 1.86 ± 0.07 dex) lies inside the so-called lithium desert in the A(Li)-Teff plane. The other object, BD+28 4515, has an A(Li) = 3.05 ± 0.07 dex, which is the highest of our sample and compatible with the expected abundances of relatively young stars.

SOFIA Science Instruments: Commissioning, Upgrades and Future Opportunities

NASA Technical Reports Server (NTRS)

Smith, Erin C.

2014-01-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is the world's largest airborne observatory, featuring a 2.5 meter telescope housed in the aft section of a Boeing 747sp aircraft. SOFIA's current instrument suite includes: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), a 5-40 µm dual band imager/grism spectrometer developed at Cornell University; HIPO (High-speed Imaging Photometer for Occultations), a 0.3-1.1 micron imager built by Lowell Observatory; FLITECAM (First Light Infrared Test Experiment CAMera), a 1-5 micron wide-field imager/grism spectrometer developed at UCLA; FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), a 42-210 micron IFU grating spectrograph completed by University Stuttgart; and EXES (Echelon-Cross- Echelle Spectrograph), a 5-28 micron high-resolution spectrometer being completed by UC Davis and NASA Ames. A second generation instrument, HAWC+ (Highresolution Airborne Wideband Camera), is a 50-240 micron imager being upgraded at JPL to add polarimetry and new detectors developed at GSFC. SOFIA will continually update its instrument suite with new instrumentation, technology demonstration experiments and upgrades to the existing instrument suite. This paper details instrument capabilities and status as well as plans for future instrumentation, including the call for proposals for 3rd generation SOFIA science instruments.

VizieR Online Data Catalog: Abundances of late-type stars (Roederer+, 2014)

NASA Astrophysics Data System (ADS)

Roederer, I. U.; Jacobson, H. R.; Thanathibodee, T.; Frebel, A.; Toller, E.

2017-01-01

We obtained observations covering the NUV spectral range from the Barbara A. Mikulski Archive for Space Telescopes (MAST). These observations were taken using the medium- or high-resolution echelle gratings in the Space Telescope Imaging Spectrograph (STIS; Kimble et al. 1998ApJ...492L..83K; Woodgate et al. 1998PASP..110.1183W) on board the Hubble Space Telescope (HST). Spectra downloaded from the MAST have been reduced by the calstis pipeline and combined by Ayres (2010, Cat. J/ApJS/187/149). Spectra obtained previously by our own observing programs were reduced by the calstis pipeline and processed as described in Roederer et al. (2012ApJS..203...27R, 2014ApJ...791...32R) and Placco et al. (2014ApJ...790...34P). (4 data files).

Precision measures of the primordial deuterium abundance.

NASA Astrophysics Data System (ADS)

Cooke, R. J.; Pettini, M.; Jorgenson, R. A.; Murphy, M. T.; Steidel, C. C.

Near-pristine damped Lyman-alpha systems (DLAs) are the ideal environments to measure the primordial abundance of deuterium. In this conference report, I summarise our ongoing research programme to obtain the most precise determination of the primordial deuterium abundance from five high redshift DLAs. From this sample, we derive (D/H)_p = (2.53±0.04)×105, corresponding to a baryon density 100 Omega_b ,0 h2 = 2.202±0.046 assuming the standard model of Big Bang Nucleosynthesis. This value is in striking agreement with that measured from the temperature fluctuations imprinted on the cosmic microwave background. Although we find no strong evidence for new physics beyond the standard model, this line of research shows great promise in the near-future, when the next generation 30+ m telescopes equipped with echelle spectrographs come online.

Radial velocity confirmation of Kepler-91 b. Additional evidence of its planetary nature using the Calar Alto/CAFE instrument

NASA Astrophysics Data System (ADS)

Lillo-Box, J.; Barrado, D.; Henning, Th.; Mancini, L.; Ciceri, S.; Figueira, P.; Santos, N. C.; Aceituno, J.; Sánchez, S. F.

2014-08-01

The object transiting the star Kepler-91 was recently assessed as being of planetary nature. The confirmation was achieved by analysing the light-curve modulations observed in the Kepler data. However, quasi-simultaneous studies claimed a self-luminous nature for this object, thus rejecting it as a planet. In this work, we apply anindependent approach to confirm the planetary mass of Kepler-91b by using multi-epoch high-resolution spectroscopy obtained with the Calar Alto Fiber-fed Echelle spectrograph (CAFE). We obtain the physical and orbital parameters with the radial velocity technique. In particular, we derive a value of 1.09 ± 0.20 MJup for the mass of Kepler-91b, in excellent agreement with our previous estimate that was based on the orbital brightness modulation.

VizieR Online Data Catalog: Lithium abundances of a large sample of red giants (Liu+, 2014)

NASA Astrophysics Data System (ADS)

Liu, Y. J.; Tan, K. F.; Wang, L.; Zhao, G.; Sato, B.; Takeda, Y.; Li, H. N.

2017-06-01

The sample stars analyzed here are comprised of 321 giants from the Okayama Planet Search Program (Sato et al. 2003ApJ...597L.157S) and 57 giants from the Xinglong Planet Search Program (Liu et al. 2008ApJ...672..553L). Both programs aim to detect planets around intermediate mass G type (and early K type) giants. The spectra were taken with the High Dispersion Echelle Spectrograph at Okayama Astrophysical Observatory (OAO), which was equipped at the coude focus of the 1.88 m telescope during 2008-2010. Before 2008 October, one CCD system with wavelength coverage of 5000-6200 Å was used, and after that the new mosaic 3 CCD system with wavelength a coverage of 4000-7540 Å replaced it. (2 data files).

Grisms Developed for FOCAS

NASA Astrophysics Data System (ADS)

Ebizuka, Noboru; Kawabata, Koji S.; Oka, Keiko; Yamada, Akiko; Kashiwagi, Masako; Kodate, Kashiko; Hattori, Takashi; Kashikawa, Nobunari; Iye, Masanori

2011-03-01

Faint Object Camera and Spectrograph (FOCAS) is a versatile common-use optical instrument for the 8.2 m Subaru Telescope, offering imaging and spectroscopic observations. FOCAS employs grisms with resolving powers ranging from 280 to 8200 as dispersive optical elements. A grism is a direct-vision grating composed of a transmission grating and prism(s). FOCAS has five grisms with replica surface-relief gratings including an echelle-type grism, and eight grisms with volume-phase holographic (VPH) gratings. The size of these grisms is 110 mm × 106 mm in aperture with a maximum thickness of 110 mm. We employ not only the dichromated gelatin, but also the hologram resin as a recording material for VPH gratings. We discuss the performance of these FOCAS grisms measured in the laboratory, and verify it by test observations, and show examples of astronomical spectroscopic observations.

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Optical Extension for Neutron Capture Elements

NASA Astrophysics Data System (ADS)

Melendez, Matthew; O'Connell, Julia; Frinchaboy, Peter M.; Donor, John; Cunha, Katia M. L.; Shetrone, Matthew D.; Majewski, Steven R.; Zasowski, Gail; Pinsonneault, Marc H.; Roman-Lopes, Alexandre; Stassun, Keivan G.; APOGEE Team

2017-01-01

The Open Cluster Chemical Abundance & Mapping (OCCAM) survey is a systematic survey of Galactic open clusters using data primarily from the SDSS-III/APOGEE-1 survey. However, neutron capture elements are very limited in the IR region covered by APOGEE. In an effort to fully study detailed Galactic chemical evolution, we are conducting a high resolution (R~60,000) spectroscopic abundance analysis of neutron capture elements for OCCAM clusters in the optical regime to complement the APOGEE results. As part of this effort, we present Ba II, La II, Ce II and Eu II results for a few open clusters without previous abundance measurements using data obtained at McDonald Observatory with the 2.1m Otto Struve telescope and Sandiford Echelle Spectrograph.This work is supported by an NSF AAG grant AST-1311835.

VizieR Online Data Catalog: Orphan stream high-resolution spectroscopic study (Casey+, 2014)

NASA Astrophysics Data System (ADS)

Casey, A. R.; Keller, S. C.; da Costa, G.; Frebel, A.; Maunder, E.

2017-06-01

High-resolution spectra for five Orphan stream candidates and seven well-studied standard stars have been obtained with the Magellan Inamori Kyocera Echelle spectrograph (Bernstein et al. 2003SPIE.4841.1694B) on the Magellan Clay telescope. These objects were observed in 2011 March using a 1" wide slit in mean seeing of 0.9". This slit configuration provides continuous spectral coverage from 333 nm to 915 nm, with a spectral resolution of R=25000 in the blue arm and R=28000 in the red arm. A minimum of 10 exposures of each calibration type (biases, flat fields, and diffuse flats) were observed in the afternoon of each day, with additional flat-field and Th-Ar arc lamp exposures performed throughout the night to ensure an accurate wavelength calibration. (3 data files).

High sensitivity, wide coverage, and high-resolution NIR non-cryogenic spectrograph, WINERED

NASA Astrophysics Data System (ADS)

Ikeda, Yuji; Kobayashi, Naoto; Kondo, Sohei; Otsubo, Shogo; Hamano, Satoshi; Sameshima, Hiroaki; Yoshikawa, Tomoshiro; Fukue, Kei; Nakanishi, Kenshi; Kawanishi, Takafumi; Nakaoka, Tetsuya; Kinoshita, Masaomi; Kitano, Ayaka; Asano, Akira; Takenaka, Keiichi; Watase, Ayaka; Mito, Hiroyuki; Yasui, Chikako; Minami, Atsushi; Izumu, Natsuko; Yamamoto, Ryo; Mizumoto, Misaki; Arasaki, Takayuki; Arai, Akira; Matsunaga, Noriyuki; Kawakita, Hideyo

2016-08-01

Near-infrared (NIR) high-resolution spectroscopy is a fundamental observational method in astronomy. It provides significant information on the kinematics, the magnetic fields, and the chemical abundances, of astronomical objects embedded in or behind the highly extinctive clouds or at the cosmological distances. Scientific requirements have accelerated the development of the technology required for NIR high resolution spectrographs using 10 m telescopes. WINERED is a near-infrared (NIR) high-resolution spectrograph that is currently mounted on the 1.3 m Araki telescope of the Koyama Astronomical Observatory in Kyoto-Sangyo University, Japan, and has been successfully operated for three years. It covers a wide wavelength range from 0.90 to 1.35 μm (the z-, Y-, and J-bands) with a spectral resolution of R = 28,000 (Wide-mode) and R = 80,000 (Hires-Y and Hires-J modes). WINERED has three distinctive features: (i) optics with no cold stop, (ii) wide spectral coverage, and (iii) high sensitivity. The first feature, originating from the Joyce proposal, was first achieved by WINERED, with a short cutoff infrared array, cold baffles, and custom-made thermal blocking filters, and resulted in reducing the time for development, alignment, and maintenance, as well as the total cost. The second feature is realized with the spectral coverage of Δλ/λ 1/6 in a single exposure. This wide coverage is realized by a combination of a decent optical design with a cross-dispersed echelle and a large format array (2k x 2k HAWAII- 2RG). The Third feature, high sensitivity, is achieved via the high-throughput optics (>60 %) and the very low noise of the system. The major factors affecting the high throughput are the echelle grating and the VPH cross-disperser with high diffraction efficiencies of 83 % and 86 %, respectively, and the high QE of HAWAII-2RG (83 % at 1.23 μm). The readout noise of the electronics and the ambient thermal background radiation at longer wavelengths could be major noise sources. The readout noise is 5.3 e- for NDR = 32, and the ambient thermal background is significantly reduced to 0.05 e- pix-1 sec-1 at 273 K. As a result, the limiting magnitudes of WINERED are estimated to be mJ = 13.8 mag for the 1.3 m telescope, mJ = 16.9 mag for the 3.6 m telescope, and mJ = 19.2 mag for 10 m telescope with adoptive optics, respectively. Finally, we introduce some scientific highlights provided by WINERED for both emission and absorption line objects in the fields of stars, the interstellar medium, and the solar system.

Control of the TSU 2-m automatic telescope

NASA Astrophysics Data System (ADS)

Eaton, Joel A.; Williamson, Michael H.

2004-09-01

Tennessee State University is operating a 2-m automatic telescope for high-dispersion spectroscopy. The alt-azimuth telescope is fiber-coupled to a conventional echelle spectrograph with two resolutions (R=30,000 and 70,000). We control this instrument with four computers running linux and communicating over ethernet through the UDP protocol. A computer physically located on the telescope handles the acquisition and tracking of stars. We avoid the need for real-time programming in this application by periodically latching the positions of the axes in a commercial motion controller and the time in a GPS receiver. A second (spectrograph) computer sets up the spectrograph and runs its CCD, a third (roof) computer controls the roll-off roof and front flap of the telescope enclosure, and the fourth (executive) computer makes decisions about which stars to observe and when to close the observatory for bad weather. The only human intervention in the telescope's operation involves changing the observing program, copying data back to TSU, and running quality-control checks on the data. It has been running reliably in this completely automatic, unattended mode for more than a year with all day-to-day adminsitration carried out over the Internet. To support automatic operation, we have written a number of useful tools to predict and analyze what the telescope does. These include a simulator that predicts roughly how the telescope will operate on a given night, a quality-control program to parse logfiles from the telescope and identify problems, and a rescheduling program that calculates new priorities to keep the frequency of observation for the various stars roughly as desired. We have also set up a database to keep track of the tens of thousands of spectra we expect to get each year.

Radial Velocity Detection of Extra-Solar Planetary Systems

NASA Technical Reports Server (NTRS)

Cochran, William D.

1998-01-01

The McDonald Observatory Planetary Search (MOPS) was designed to search for Jovian-mass planets in orbit around solar-type stars by making high-precision measurements of the Radial Velocity (RV) of a star, to attempt to detect the reflex orbital motion of the star around the star-planet barycenter. In our solar system, the velocity of the Sun around the Sun-Jupiter barycenter averages 12.3 m/ s. The MOPS survey started operation in September 1987, and searches 36 bright, nearby, solar-type dwarfs to 10 m/s precision. The survey was started using telluric O2 absorption lines as the velocity reference metric. Observations use the McDonald Observatory 2.7-m Harlan Smith Telescope coude spectrograph with the six-foot camera. This spectrograph configuration isolates a single order of the echelle grating on a Texas Instruments 800 x 800 CCD. The telluric line method gave us a routine radial velocity precision of about 15 m/s for stars down to about 5-th magnitude. However, the data obtained with this technique suffered from some source of long-term systematic errors, which was probably the intrinsic velocity variability of the terrestrial atmosphere, i.e. winds. In order to eliminate this systematic error and to improve our overall measurement precision, we installed a stabilized I2 gas absorption cell as the velocity metric for the MOPS in October 1990. In use at the telescope, the cell is placed directly in front of the spectrograph entrance slit, with starlight passing through the cell. The use of this sealed stabilized I2 cell removes potential problems with possible long-term drifts in the velocity metric. The survey now includes a sample of 36 nearby F, G, and K type stars of luminosity class V or IV-V.

A search for stars of very low metal abundance. VI. Detailed abundances of 313 metal-poor stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roederer, Ian U.; Preston, George W.; Thompson, Ian B.

2014-06-01

We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10 yr observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coudé Spectrograph on the Harlan J. Smith Telescope atmore » McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by ≈0.25 dex for red giants and ≈0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] ≤–3.5, 84 stars with [Fe/H] ≤–3.0, and 210 stars with [Fe/H] ≤–2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] ≤–2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.« less

Observations of hydrogen-rich supernovae in the first days after explosion and new instruments to study them

NASA Astrophysics Data System (ADS)

Rubin, Adam; PTF

2018-01-01

I will discuss our results studying light curves of hydrogen-rich supernovae during the first few days after explosion. The first days of emission encode important information about the physical system, and it is possible to relate the early-time light curve to the radius of the progenitor star by using shock-cooling models. I will show the first systematic application of these models to data from the Palomar Transient Factory (PTF). We found that R-band data alone at PTF cadence cannot constrain the radius but can constrain the energy per unit mass of the explosion, uncovering new correlations with other supernova observables. We constrained the radii for events with multi-wavelength observations, and for two events observed with the Kepler mission at 30 min cadence. I will discuss improved observing strategies to obtain more constraining results in the future. Some tensions have arisen between our results and the expected radii from identified progenitors of hydrogen-rich supernovae. The resolution of these tensions may be related to the effect of circumstellar material on the light curves, motivating future systematic spectroscopic sequencing of these events. To this end, we have designed a new medium resolution UV-VIS spectrograph. The Multi-Imaging Transient Spectrograph (MITS) is the R~4500 UV-VIS arm of the Son Of X-Shooter (SOXS) spectrograph proposed for ESO’s 3.6 m New Technology Telescope. Our design divides the spectrum into several sub-bands, allowing optimization for each narrow part of the spectrum. We estimate a 50-100% improvement in throughput relative to a classical 4-C echelle design. Our design has passed a preliminary design review and is expected on the telescope in early 2021.

A preliminary design for the GMT-Consortium Large Earth Finder (G-CLEF)

NASA Astrophysics Data System (ADS)

Szentgyorgyi, Andrew; Barnes, Stuart; Bean, Jacob; Bigelow, Bruce; Bouchez, Antonin; Chun, Moo-Young; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Frebel, Anna; Furesz, Gabor; Glenday, Alex; Guzman, Dani; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jeong, Ueejong; Jordan, Andres; Kim, Kang-Min; Kim, Jihun; Li, Chih-Hao; Lopez-Morales, Mercedes; McCracken, Kenneth; McLeod, Brian; Mueller, Mark; Nah, Jakyung; Norton, Timothy; Oh, Heeyoung; Oh, Jae Sok; Ordway, Mark; Park, Byeong-Gon; Park, Chan; Park, Sung-Joon; Phillips, David; Plummer, David; Podgorski, William; Rodler, Florian; Seifahrt, Andreas; Tak, Kyung-Mo; Uomoto, Alan; Van Dam, Marcos A.; Walsworth, Ronald; Yu, Young Sam; Yuk, In-Soo

2014-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) is an optical-band echelle spectrograph that has been selected as the first light instrument for the Giant Magellan Telescope (GMT). G-CLEF is a general-purpose, high dispersion spectrograph that is fiber fed and capable of extremely precise radial velocity measurements. The G-CLEF Concept Design (CoD) was selected in Spring 2013. Since then, G-CLEF has undergone science requirements and instrument requirements reviews and will be the subject of a preliminary design review (PDR) in March 2015. Since CoD review (CoDR), the overall G-CLEF design has evolved significantly as we have optimized the constituent designs of the major subsystems, i.e. the fiber system, the telescope interface, the calibration system and the spectrograph itself. These modifications have been made to enhance G-CLEF's capability to address frontier science problems, as well as to respond to the evolution of the GMT itself and developments in the technical landscape. G-CLEF has been designed by applying rigorous systems engineering methodology to flow Level 1 Scientific Objectives to Level 2 Observational Requirements and thence to Level 3 and Level 4. The rigorous systems approach applied to G-CLEF establishes a well defined science requirements framework for the engineering design. By adopting this formalism, we may flexibly update and analyze the capability of G-CLEF to respond to new scientific discoveries as we move toward first light. G-CLEF will exploit numerous technological advances and features of the GMT itself to deliver an efficient, high performance instrument, e.g. exploiting the adaptive optics secondary system to increase both throughput and radial velocity measurement precision.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulkarni, Varsha P.; Som, Debopam; Morrison, Sean

We report Keck/Echellette Spectrograph and Imager and Very Large Telescope/Ultraviolet-Visual Echelle Spectrograph observations of three super-damped Lyα quasar absorbers with H i column densities log N{sub H} {sub i} ≥ 21.7 at redshifts 2 ≲ z ≲ 2.5. All three absorbers show similar metallicities (∼−1.3 to −1.5 dex), and dust depletion of Fe, Ni, and Mn. Two of the absorbers show supersolar [S/Zn] and [Si/Zn]. We combine our results with those for other damped Lyα a absorbers (DLAs) to examine trends between N{sub H} {sub i}, metallicity, and dust depletion. A larger fraction of the super-DLAs lie close to ormore » above the line [X/H] = 20.59 − log N{sub H} {sub i} in the metallicity versus N{sub H} {sub i} plot, compared to the less gas-rich DLAs, suggesting that super-DLAs are more likely to be rich in molecules. Unfortunately, our data for Q0230−0334 and Q0743+1421 do not cover H{sub 2} absorption lines. For Q1418+0718, some H{sub 2} lines are covered, but not detected. CO is not detected in any of our absorbers. For DLAs with log N{sub H} {sub i} < 21.7, we confirm strong correlation between metallicity and Fe depletion, and find a correlation between metallicity and Si depletion. For super-DLAs, these correlations are weaker or absent. The absorbers toward Q0230−0334 and Q1418+0718 show potential detections of weak Lyα emission, implying star formation rates of ∼1.6 and ∼0.7 M{sub ⊙} yr{sup −1}, respectively (ignoring dust extinction). Upper limits on the electron densities from C ii*/C ii or Si ii*/Si ii are low, but are higher than the median values in less gas-rich DLAs. Finally, systems with log N{sub H} {sub i} > 21.7 may have somewhat narrower velocity dispersions Δv{sub 90} than the less gas-rich DLAs, and may arise in cooler and/or less turbulent gas.« less

VizieR Online Data Catalog: Spectroscopy and photometry for HAT-P-50--HAT-P-53 (Hartman+, 2015)

NASA Astrophysics Data System (ADS)

Hartman, J. D.; Bhatti, W.; Bakos, G. A.; Bieryla, A.; Kovacs, G.; Latham, D. W.; Csubry, Z.; de Val-Borro, M.; Penev, K.; Buchhave, L. A.; Torres, G.; Howard, A. W.; Marcy, G. W.; Johnson, J. A.; Isaacson, H.; Sato, B.; Boisse, I.; Falco, E.; Everett, M. E.; Szklenar, T.; Fulton, B. J.; Shporer, A.; Kovacs, T.; Hansen, T.; Beky, B.; Noyes, R. W.; Lazar, J.; Papp, I.; Sari, P.

2016-04-01

The HATNet network consists of six identical fully automated instruments, with four at Fred Lawrence Whipple Observatory (FLWO) in AZ, and two on the roof of the Submillimeter Array Hangar Building at Mauna Kea Observatory (MKO) in HI. The light-gathering elements of each instrument include an 11cm diameter telephoto lens, a Sloan r filter, and a 4K*4K front-side-illuminated CCD camera. Observations made in 2007 and early 2008 were carried out using a Cousins R filter. The instruments have a field of view of 10.6°*10.6° and a pixel scale of 9"/pixel at the center of an image. Additional time-series photometric measurements were obtained for all four of the systems using Keplercam on the FLWO 1.2m telescope. For HAT-P-50 we also obtained follow-up photometry with the CCD imager on the Byrne Observatory at Sedgwick (BOS) 0.8m telescope, located at Sedgwick Reserve in Santa Ynez Valley, CA, and operated by the Las Cumbres Observatory Global Telescope institute (LCOGT). HAT-P-50 was observed with HAT-10/G316 on 2008 Nov-2009 May, with HAT-5/G364 on 2009 May, with HAT-9/G364 on 2008 Dec-2009 May, with BOS on 2012 Feb 15, on 2012 Feb 21 and on 2012 Apr 08, and with Keplercam on 2012 Feb 18, on 2012 Nov 28, on 2012 Dec 23, on 2013 Jan 14, and on 2013 Jan 17. HAT-P-51 was observed with HAT-6/G164 on 2007 Sep-2008 Feb, with HAT-9/G164 on 2007 Sep-2008 Feb, with HAT-10/G165 on 2010 Sep-2011 Jan, with HAT-5/G165 on 2010 Nov-2011 Feb, with HAT-8/G165 on 2010 Nov-2011 Feb, with HAT-6/G209 on 2010 Nov-2011 Feb, with HAT-9/G209 on 2010 Nov-2011 Feb, with HAT-7/G210 on 2010 Nov-2011 Jan, and with Keplercam on 2011 Oct 21, on 2012 Jan 05, on 2012 Oct 05, on 2012 Oct 26, and on 2012 Nov 12. HAT-P-52 was observed with HAT-5/G212 on 2010 Sep-Nov, with HAT-8/G212 on 2010 Aug-Nov, and with Keplercam on 2010 Dec 23, on 2011 Sep 05, on 2011 Sep 27, on 2011 Nov 21, and on 2012 Jan 07. HAT-P-53 was observed with HAT-6/G164 on 2007 Sep-2008 Feb, with HAT-9/G164 on 2007 Sep-2008 Feb, with HAT-10/G165 on 2010 Sep-2011 Jan, with HAT-5/G165 on 2010 Nov-2011 Feb, with HAT-8/G165 on 2010 Nov-2011 Feb, and with Keplercam on 2011 Oct 19 and on 2011 Oct 27. The facilities used for each system include the Tillinghast Reflector Echelle Spectrograph (TRES; Resolution Δλ/λ/1000=44) on the 1.5m Tillinghast Reflector at FLWO (used on 2010 Dec-2012 Feb for HAT-P-50, on 2011 Sep 21 for HAT-P-51, on 2010 Dec-2011 Jan for HAT-P-52, and on 2011 Sep 18-19 for HAT-P-53); the Astrophysical Research Consortium Echelle Spectrometer (ARCES; Resolution Δλ/λ/1000=31.5) on the ARC 3.5m telescope at Apache Point Observatory (APO) in New Mexico (used on 2011 Sep 19 for HAT-P-51, and on 2011 Sep 19-20 for HAT-P-53); the FIbre-fed Echelle Spectrograph (FIES) at the 2.5m Nordic Optical Telescope (NOT) at La Palma, Spain (used on 2012 Mar 13-17 with Δλ/λ/1000=67 for HAT-P-50, and on 2011 Aug 4 with Δλ/λ/1000=46 for HAT-P-51); the SOPHIE Spectrograph (Resolution Δλ/λ/1000=39) on the 1.93m telescope at OHP in France (used for HAT-P-51 on 2011 Dec 4-12; the HIgh Resolution Echelle Spectrometer (HIRES; Resolution Δλ/λ/1000=55) on the Keck-I telescope in Hawaii together with the I2 absorption cell (used on 2011 Oct-2012 Feb for HAT-P-51, on 2011 Oct 19 and 2011 Feb-2012 Jul for HAT-P-52, and on 2011 Nov 14 and 2011 Nov-2012 Feb for HAT-P-53); and the High-Dispersion Spectrograph (HDS; Resolution Δλ/λ/1000=60) with the I2 absorption cell on the Subaru telescope in Hawaii (used on 2012 Feb 7 and 2012 Feb-Sep for HAT-P-50, and on 2012 Feb 9 and 2012 Feb 7-10 for HAT-P-51). The high-precision radial velocity measurements for all objects are seen to vary in phase with the transit ephemerides. The data are listed in Table4. All photometric measurements made for the four objects are available in Table5. (3 data files).

A Spectroscopic Study of the High-Latitude Far Evolved Star V534 Lyr

NASA Astrophysics Data System (ADS)

Sendzikas, E. G.; Chentsov, E. L.

2017-06-01

We study a pulsating variable post-AGB star V534 Lyr = HD172324 based on five high resolution spectra (R=60000) obtained with the NES echelle spectrograph of the 6-meter Russian telescope (BTA) in 2010 and 2013. Using the atmosphere modeling method and the Kurucz model set, we obtained the effective temperature Teff=10500 K, surface gravity log g=2.5, and microturbulent velocity ξt=4.0 km/s. The underabundance of the iron group elements [Met/H]⊙ = -0.50 was detected. This fact in combination with high spatial velocity indicates that V534 Lyr does not belong to the disk population. The radial velocity gradient in the V534 Lyr atmosphere is minimum: differential shifts of lines are close to measurement errors. The spectral class A0 Iab corresponds to the distance to V534 Lyr, d≍6 kpc.

Determination of Li abundance in Solar type stars of intermediate brightness

NASA Astrophysics Data System (ADS)

Amazo-Gómez, E. M.; Hernandez-Águila, B.; Dagostino, M. C.; Bertone, E.; de la Luz, V.

2014-10-01

The determination of the lithium abundance in stellar atmospheres is of fundamental importance in multiple contexts of contemporary astrophysics. On the one hand, the lithium present in stars with global sub-solar metal abundances provides a strong restriction on the abundance of this element as a result of primordial nucleo-synthesis. On the other hand, Li can be an age indicator for stars with convective envelopes. Additionally, Li abundance appears to be correlated with the presence of sub-stellar companions. We present preliminary results of a project aimed at determining the Li abundance in an extended sample of solar-like stars (spectral type G and luminosity class V) of intermediate brightness. High resolution spectroscopic data (R=65000) were obtained with the CanHiS echelle spectrograph on the 2.11m telescope of the Guillermo Haro Observatory in Cananea, Sonora, Mexico. We report the equivalent widths of a first sub-sample of 33 stars.

VizieR Online Data Catalog: Spectral atlas of HD 50138 (Borges Fernandes+, 2009)

NASA Astrophysics Data System (ADS)

Borges Fernandes, M.; Kraus, M.; Chesneau, O.; Domiciano de Souza, A.; de Araujo, F. X.; Stee, P.; Meilland, A.

2009-09-01

In this table, it is described the lines identified, with their radial velocities and equivalent widths in the high-resolution FEROS spectra obtained in 1999 and 2007. FEROS is a bench-mounted Echelle spectrograph with fibers, which covers a sky area of 2" of diameter, with a wavelength coverage from 360nm to 920nm and a spectral resolution of R=55000 (in the region around 600nm). The spectrum of 1999 was obtained with an exposure time of 180 seconds and has a S/N ratio of approximately 80 in the 550nm region. In 2007, we were able to take two consecutive spectra of the star, both with 180 seconds of exposure time. Since these spectra do not show significant differences, we added them up for a better S/N ratio, which is around 250. (1 data file).

VizieR Online Data Catalog: KODIAQ DR2 (O'Meara+, 2017)

NASA Astrophysics Data System (ADS)

O'Meara, J. M.; Lehner, N.; Howk, J. C.; Prochaska, J. X.; Fox, A. J.; Peeples, M. S.; Tumlinson, J.; O'Shea, B. W.

2018-02-01

The new data presented here in DR2 all stem from High-Resolution Echelle Spectrograph (HIRES) observations by multiple PIs between 1995 and 2004. Table1 presents the HIRES deckers used across DR2 and their corresponding spectral resolution. As with DR1, the majority of observations were made with the C1 or C5 decker providing ~6 and ~8km/s FWHM resolution, respectively. The Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ) DR2 comprises HIRES observations of 300 quasar lines of sight in total. Of these, 130 quasar sight lines are new since DR1 (O'Meara et al. 2015, Cat. J/AJ/150/111), along with many new additional observations of some of the DR1 quasars. Table2 presents the new data since DR1. Table3 presents the full DR2 sample of 300 quasars. (3 data files).

Observations of potassium in the tenuous lunar atmosphere

NASA Technical Reports Server (NTRS)

Kozlowski, Richard W. H.; Sprague, Ann L.; Hunten, Donald M.

1990-01-01

Observations of neutral potassium (K) in the tenuous lunar atmosphere are described. An echelle spectrograph, CCD, and data acquisition system are used to obtain emission spectra of neutral K atoms in the lunar atmosphere as observed by the 1.54 telescope at the Catalina Observatory at first quarter the night of April 29, 1989. A table of relevant lunar atmosphere parameters summarizes the results of the investigation. It is found that the number density at the surface is 9.5 + or - 1 atoms per cu cm and that there is a large nonthermal component and a deficiency of atoms equilibrated to the surface temperature. The calculated thermalization rate of the nonthermal component through encounters with the lunar surface gives a source of strength for the thermal component factor of 7 greater than loss by photoionization. Possible explanations for the low thermalized population observed are considered.

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Current Status

NASA Astrophysics Data System (ADS)

Frinchaboy, Peter; O'Connell, Julia; Donor, John; Cunha, Katia; Thompson, Benjamin; Melendez, Matthew; Shetrone, Matthew; Zasowski, Gail; Majewski, Steven R.; APOGEE TEAM

2018-01-01

The Open Cluster Chemical Analysis and Mapping (OCCAM) survey aims to produce a comprehensive, uniform, infrared-based data set forhundreds of open clusters, and constrain key Galactic dynamical and chemical parameters using the SDSS/APOGEE survey and follow-up from the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We report on multi-element radial abundance gradients obtained from a sample of over 30 disk open clusters. The APOGEE chemical abundances were derived automatically by the ASPCAP pipeline and these are part of the SDSS IV Data Release 14, optical follow-up were analyzed using equivalent width analysis and spectral synthesis. We present the current open cluster sample that spans a significant range in age allowing exploration of the evolution of the Galactic abundance gradients. This work is supported by an NSF AAG grants AST-1311835 & AST-1715662.

Successful "First Light" for VLT High-Resolution Spectrograph

NASA Astrophysics Data System (ADS)

1999-10-01

Great Research Prospects with UVES at KUEYEN A major new astronomical instrument for the ESO Very Large Telescope at Paranal (Chile), the UVES high-resolution spectrograph, has just made its first observations of astronomical objects. The astronomers are delighted with the quality of the spectra obtained at this moment of "First Light". Although much fine-tuning still has to be done, this early success promises well for new and exciting science projects with this large European research facility. Astronomical instruments at VLT KUEYEN The second VLT 8.2-m Unit Telescope, KUEYEN ("The Moon" in the Mapuche language), is in the process of being tuned to perfection before it will be "handed" over to the astronomers on April 1, 2000. The testing of the new giant telescope has been successfully completed. The latest pointing tests were very positive and, from real performance measurements covering the entire operating range of the telescope, the overall accuracy on the sky was found to be 0.85 arcsec (the RMS-value). This is an excellent result for any telescope and implies that KUEYEN (as is already the case for ANTU) will be able to acquire its future target objects securely and efficiently, thus saving precious observing time. This work has paved the way for the installation of large astronomical instruments at its three focal positions, all prototype facilities that are capable of catching the light from even very faint and distant celestial objects. The three instruments at KUEYEN are referred to by their acronyms UVES , FORS2 and FLAMES. They are all dedicated to the investigation of the spectroscopic properties of faint stars and galaxies in the Universe. The UVES instrument The first to be installed is the Ultraviolet Visual Echelle Spectrograph (UVES) that was built by ESO, with the collaboration of the Trieste Observatory (Italy) for the control software. Complete tests of its optical and mechanical components, as well as of its CCD detectors and of the complex control system, cf. ESO PR Photos 44/98 , were made in the laboratories of the ESO Headquarters in Garching (Germany) before it was fully dismounted and shipped (some parts by air, others by ship) to the ESO Paranal Observatory, 130 km south of Antofagasta (Chile). Here, the different pieces of UVES (with a total weight of 8 tons) were carefully reassembled on the Nasmyth platform of KUEYEN and made ready for real observations (see ESO PR Photos 36p-t/99 ). UVES is a complex two-channel spectrograph that has been built around two giant optical (echelle diffraction) gratings, each ruled on a 84 cm x 21 cm x 12 cm block of the ceramic material Zerodur (the same that is used for the VLT 8.2-m main mirrors) and weighing more than 60 kg. These echelle gratings finely disperse the light from celestial objects collected by the telescope into its constituent wavelengths (colours). UVES' resolving power (an optical term that indicates the ratio between a given wavelength and the smallest wavelength difference between two spectral lines that are clearly separated by the spectrograph) may reach 110,000, a very high value for an astronomical instrument of such a large size. This means for instance that even comparatively small changes in radial velocity (a few km/sec only) can be accurately measured and also that it is possible to detect the faint spectral signatures of very rare elements in celestial objects. One UVES channel is optimized for the ultraviolet and blue, the other for visual and red light. The spectra are digitally recorded by two highly efficient CCD detectors for subsequent analysis and astrophysical interpretation. By optimizing the transmission of the various optical components in its two channels, UVES has a very high efficiency all the way from the UV (wavelength about 300 nm) to the near-infrared (1000 nm or 1 µm). This guarantees that only a minimum of the precious light that is collected by KUEYEN is lost and that detailed spectra can be obtained of even quite faint objects, down to about magnitude 20 (corresponding to nearly one million times fainter than what can be perceived with the unaided eye). The possibility of doing simultaneous observations in the two channels (with a dichroic mirror) ensures a further gain in data gathering efficiency. First Observations with UVES In the evening of September 27, 1999, the ESO astronomers turned the KUEYEN telescope and - for the first time - focussed the light of stars and galaxies on the entrance aperture of the UVES instrument. This is the crucial moment of "First Light" for a new astronomical facility. The following test period will last about three weeks. Much of the time during the first observing nights was spent by functional tests of the various observation modes and by targeting "standard stars" with well-known properties in order to measure the performance of the new instrument. They showed that it is behaving very well. This marks the beginning of a period of progressive fine-tuning that will ultimately bring UVES to peak performance. The astronomers also did a few "scientific" observations during these nights, aimed at exploring the capabilities of their new spectrograph. They were eager to do so, also because UVES is the first spectrograph of this type installed at a telescope of large diameter in the southern hemisphere . Many exciting research possibilities are now opening with UVES . They include a study of the chemical history of many galaxies in the Local Group, e.g. by observing the most metal-poor (oldest) stars in the Milky Way Galaxy and by obtaining the first, extremely detailed spectra of their brightest stars in the Magellanic Clouds. Quasars and distant compact galaxies will also be among the most favoured targets of the first UVES observers, not least because their spectra carry crucial information about the density, physical state and chemical composition of the early Universe. UVES First Light: SN 1987A One of the first spectral test exposures with UVES at KUEYEN was of SN 1987A , the famous supernova that exploded in the Large Magellanic Cloud (LMC) in February 1987, and the brightest supernova of the last 400 years. ESO PR Photo 37a/99 ESO PR Photo 37a/99 [Preview - JPEG: 400 x 455 pix - 87k] [Normal - JPEG: 645 x 733 pix - 166k] Caption to ESO PR Photo 37a/99 : This is a direct image of SN1987A, flanked by two nearby stars. The distance between these two is 4.5 arcsec. The slit (2.0 arcsec wide) through which the echelle spectrum shown in PR Photo 37b/99 was obtained, is outlined. This reproduction is from a 2-min exposure through a R(ed) filter with the FORS1 multi-mode instrument at VLT ANTU, obtained in 0.55 arcsec seeing on September 20, 1998. North is up and East is left. ESO PR Photo 37b/99 ESO PR Photo 37b/99 [Preview - JPEG: 400 x 459 pix - 130k] [Normal - JPEG: 800 x 917 pix - 470k] [High-Res - JPEG: 3000 x 3439 pix - 6.5M] Caption to ESO PR Photo 37b/99 : This shows the raw image, as read from the CCD, with the recorded echelle spectrum of SN1987A. With this technique, the supernova spectrum is divided into many individual parts ( spectral orders , each of which appears as a narrow horizontal line) that together cover the wavelength interval from 479 to 682 nm (from the bottom to the top), i.e. from blue to red light. Many bright emission lines from different elements are visible, e.g. the strong H-alpha line from hydrogen near the centre of the fourth order from the top. Emission lines from the terrestrial atmosphere are seen as vertical bright lines that cover the full width of the individual horizontal bands. Since this exposure was done with the nearly Full Moon above the horizon, an underlying, faint absorption-line spectrum of reflected sunlight is also visible. The exposure time was 30 min and the seeing conditions were excellent (0.5 arcsec). ESO PR Photo 37c/99 ESO PR Photo 37c/99 [Preview - JPEG: 400 x 355 pix - 156k] [Normal - JPEG: 800 x 709 pix - 498k] [High-Res - JPEG: 1074 x 952 pix - 766k] Caption to ESO PR Photo 37c/99 : This false-colour image has been extracted from another UVES echelle spectrum of SN 1987A, similar to the one shown in PR Photo 37b/99 , but with a slit width of 1 arcsec only. The upper part shows the emission lines of nitrogen, sulfur and hydrogen, as recorded in some of the spectral orders. The pixel coordinates (X,Y) in the original frame are indicated; the red colour indicates the highest intensities. Below is a more detailed view of the complex H-alpha emission line, with the corresponding velocities and the position along the spectrograph slit indicated. Several components of this line can be distinguished. The bulk of the emission (here shown in red colour) comes from the ring surrounding the supernova; the elongated shape here is due to the differential velocity exhibited by the near (to us) and far sides of the ring. The two bright spots on either side are emission from two outer rings (not immediately visible in PR Photo 37a/99 ). The extended emission in the velocity direction originates from material inside the ring upon which the fastest moving ejecta from the supernova have impacted (As seen in VLT data obtained previously with the ANTU/ISAAC combination (cf. PR Photo 11/99 ), exciting times now lie ahead for SN 1987A. The ejecta moving at 30,000 km/s (1/10th the speed of light) have now, 12 years after the explosion, reached the ring of material and the predicted "fireworks" are about to be ignited.) Finally, there is a broad emission extending all along the spectrograph slit (here mostly yellow) upon which the ring emission is superimposed. This is not associated with the supernova itself, but is H-alpha emission by diffuse gas in the Large Magellanic Cloud (LMC) in which SN 1987A is located. UVES First Light: QSO HE2217-2818 The power of UVES is demonstrated by this two-hour test exposure of the southern quasar QSO HE2217-2818 with U-magnitude = 16.5 and a redshift of z = 2.4. It was discovered a few years ago during the Hamburg-ESO Quasar Survey , by means of photographic plates taken with the 1-m ESO Schmidt Telescope at La Silla, the other ESO astronomical site in Chile. ESO PR Photo 37d/99 ESO PR Photo 37d/99 [Preview - JPEG: 400 x 309 pix - 92k] [Normal - JPEG: 800x 618 pix - 311k] [High-Res - JPEG: 3000 x 2316 pix - 5.0M] ESO PR Photo 37e/99 ESO PR Photo 37e/99 [Preview - JPEG: 400 x 310 pix - 43k] [Normal - JPEG: 800 x 619 pix - 100k] [High-Res - JPEG: 3003 x 2324 pix - 436k] Caption to ESO PR Photo 37d/99 : This UVES echelle spectrum QSO HE2217-2818 (U-magnitude = 16.5) is recorded in different orders (the individual horizontal lines) and altogether covers the wavelength interval between 330 - 450 nm (from the bottom to the top). It illustrates the excellent capability of UVES to work in the UV-band on even faint targets. Simultaneously with this observation, UVES also recorded the adjacent spectral region 465 - 660 nm in its other channel. The broad Lyman-alpha emission from ionized hydrogen associated with the powerful energy source of the QSO is seen in the upper half of the spectrum at wavelength 413 nm. At shorter wavelengths, the dark regions in the spectrum are Lyman-alpha absorption lines from intervening, neutral hydrogen gas located along the line-of-sight at different redshifts (the so-called Lyman-alpha forest ) in the redshift interval z = 1.7 - 2.4. Note that since this exposure was done with the nearly Full Moon above the horizon, an underlying, faint absorption-line spectrum of reflected sunlight is also visible. Caption to ESO PR Photo 37e/99 : A tracing of one spectral order, corresponding to one horizontal line in the echelle spectrum displayed in PR Photo 37d/99 . It shows part of the Lyman-alpha forest in the ultraviolet spectrum of the southern quasar QSO HE2217-2818 . The absorption lines are caused by intervening, neutral hydrogen gas located at different distances along the line-of-sight towards this quasar. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

VizieR Online Data Catalog: iz follow-up photometry of HAT-P-65 and HAT-P-66 (Hartman+, 2016)

NASA Astrophysics Data System (ADS)

Hartman, J. D.; Bakos, G. A.; Bhatti, W.; Penev, K.; Bieryla, A.; Latham, D. W.; Kovacs, G.; Torres, G.; Csubry, Z.; de Val-Borro, M.; Buchhave, L.; Kovacs, T.; Quinn, S.; Howard, A. W.; Isaacson, H.; Fulton, B. J.; Everett, M. E.; Esquerdo, G.; Beky, B.; Szklenar, T.; Falco, E.; Santerne, A.; Boisse, I.; Hebrard, G.; Burrows, A.; Lazar, J.; Papp, I.; Sari, P.

2017-05-01

Both HAT-P-65 and Both HAT-P-66 were selected as candidate transiting planet systems based on Sloan r-band photometric time series observations carried out with the HATNet telescope network. HATNet consists of six 11cm aperture telephoto lenses, each coupled to an APOGEE front-side-illuminated CCD camera, and each placed on a fully automated telescope mount. Four of the instruments are located at Fred Lawrence Whipple Observatory (FLWO) in Arizona, USA, while two are located on the roof of the Submillimeter Array hangar building at Mauna Kea Observatory (MKO) on the island of Hawaii, USA. Each instrument observes a 10.6°*10.6° field of view. We conducted follow-up photometric time series observations of each object using KeplerCam on the 1.2m telescope at FLWO. HAT-P-65 was observed on 2009 Sep-Dec with a r-band filter using the HAT-6/G342 (located at FLWO) and the HAT-8/G342 (located on the roof of the Smithsonian Astrophysical Observatory Submillimeter Array hangar building at Mauna Kea Observatory in Hawaii), and on 2011 Jun 10 (i filter), 2011 Jun 26 (i filter), 2011 Jul 14 (i filter), 2011 Sep 20 (i filter), 2013 Sep 16 (z filter), 2013 Sep 29 (i filter), and 2013 Oct 04 (i filter) using the FLWO 1.2m/KeplerCam. HAT-P-66 was observed on 2011 Feb-2012 Mar using the HAT-10/G101 (located at FLWO) with a r-band filter, using the HAT-6/G101 (located at FLWO) with a r-band filter, and using the HAT-7/G101 (located at FLWO) with a r-band filter, on 2011 Feb-2012 Apr using the HAT-5/G101 (located at FLWO) with a r-band filter, on 2011 May-2012 Jun using the HAT-8/G101 (located on the roof of the Smithsonian Astrophysical Observatory Submillimeter Array hangar building at Mauna Kea Observatory in Hawaii) with a r-band filter, on 2011 Oct-2012 Jan using the HAT-9/G101 (located at FLWO) with a r-band filter, and on 2015 Apr 29 (i filter), 2015 Nov 26 (z filter), 2015 Dec 08 (i filter) using the FLWO 1.2m/KeplerCam. Spectroscopic observations of both HAT-P-65 and HAT-P-66 were carried out using the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5m Tillinghast Reflector at FLWO (on 2010 Oct 27 for HAT-P-65, and 2014 Nov-2015 Jun for HAT-P-66), and the HIgh-Resolution Echelle Spectrometer (HIRES) on the Keck I 10m at Mauna Kea Observatory (MKO) on the island of Hawaii, USA (on 2010 Dec 14 and 2010 Dec-2013 Aug for HAT-P-65, and on 2016 Feb 3 and 2015 Dec-2016 Jan for HAT-P-66). For HAT-P-65 we also obtained observations on 2010 Aug 21-22 and 2011 Oct 8 using the Fibre-fed Echelle Spectrograph (FIES) on the 2.5m Nordic Optical Telescope (NOT) at the Observatorio del Roque de los Muchachos on the Spanish island of La Palma. For HAT-P-66 spectroscopic observations were also collected on 2015 Mar-2016 Jan using the SOPHIE spectrograph on the 1.93m telescope at the Observatoire de Haute-Provence (OHP) in France. The light curve measurements are available in Table2. The individual radial velocity and bisector span measurements are made available in Table4. (5 data files).

Stable and unstable accretion in the classical T Tauri stars IM Lup and RU Lup as observed by MOST

NASA Astrophysics Data System (ADS)

Siwak, Michal; Ogloza, Waldemar; Rucinski, Slavek M.; Moffat, Anthony F. J.; Matthews, Jaymie M.; Cameron, Chris; Guenther, David B.; Kuschnig, Rainer; Rowe, Jason F.; Sasselov, Dimitar; Weiss, Werner W.

2016-03-01

Results of the time variability monitoring of the two classical T Tauri stars, RU Lup and IM Lup, are presented. Three photometric data sets were utilized: (1) simultaneous (same field) MOST satellite observations over four weeks in each of the years 2012 and 2013, (2) multicolour observations at the South African Astronomical Observatory in April-May of 2013, (3) archival V-filter All Sky Automated Survey (ASAS) data for nine seasons, 2001-2009. They were augmented by an analysis of high-resolution, public-domain VLT-UT2 Ultraviolet Visual Echelle Spectrograph spectra from the years 2000 to 2012. From the MOST observations, we infer that irregular light variations of RU Lup are caused by stochastic variability of hotspots induced by unstable accretion. In contrast, the MOST light curves of IM Lup are fairly regular and modulated with a period of about 7.19-7.58 d, which is in accord with ASAS observations showing a well-defined 7.247 ± 0.026 d periodicity. We propose that this is the rotational period of IM Lup and is due to the changing visibility of two antipodal hotspots created near the stellar magnetic poles during the stable process of accretion. Re-analysis of RU Lup high-resolution spectra with the broadening function approach reveals signs of a large polar coldspot, which is fairly stable over 13 years. As the star rotates, the spot-induced depression of intensity in the broadening function profiles changes cyclically with period 3.710 58 d, which was previously found by the spectral cross-correlation method.

Analysis of molecular hydrogen absorption toward QSO B0642–5038 for a varying proton-to-electron mass ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagdonaite, J.; Ubachs, W.; Murphy, M. T.

2014-02-10

Rovibronic molecular hydrogen (H{sub 2}) transitions at redshift z {sub abs} ≅ 2.659 toward the background quasar B0642–5038 are examined for a possible cosmological variation in the proton-to-electron mass ratio μ. We utilize an archival spectrum from the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph (UVES) with a signal-to-noise ratio of ∼35 per 2.5 km s{sup –1} pixel at the observed H{sub 2} wavelengths (335-410 nm). Some 111 H{sub 2} transitions in the Lyman and Werner bands have been identified in the damped Lyα system for which a kinetic gas temperature of ∼84 K and a molecular fraction log fmore » = –2.18 ± 0.08 are determined. The H{sub 2} absorption lines are included in a comprehensive fitting method, which allows us to extract a constraint on a variation of the proton-electron mass ratio Δμ/μ from all transitions at once. We obtain Δμ/μ = (17.1 ± 4.5{sub stat} ± 3.7{sub sys}) × 10{sup –6}. However, we find evidence that this measurement has been affected by wavelength miscalibration errors recently identified in UVES. A correction based on observations of objects with solar-like spectra gives a smaller Δμ/μ value and contributes to a larger systematic uncertainty: Δμ/μ = (12.7 ± 4.5{sub stat} ± 4.2{sub sys}) × 10{sup –6}.« less

Post - SM4 Flux Calibration of the STIS Echelle Modes

NASA Astrophysics Data System (ADS)

Bostroem, Azalee; Aloisi, A.; Bohlin, R. C.; Proffitt, C. R.; Osten, R. A.; Lennon, D.

2010-07-01

Like all STIS spectroscopic modes, STIS echelle modes show a wavelength dependent decline in detector sensitivity with time. The echelle sensitivity is further affected by a time-dependent shift in the blaze function. To better correct the effects of the echelle sensitivity loss and the blaze function changes, we derive new baselines for echelle sensitivities from post-HST Servicing Mission 4 observations of the standard star G191-B2B. We present how these baseline sensitivities compare to pre-failure trends.

Integration of the instrument control electronics for the ESPRESSO spectrograph at ESO-VLT

NASA Astrophysics Data System (ADS)

Baldini, V.; Calderone, G.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Mégevand, D.; Riva, M.; Santin, P.

2016-07-01

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations of the ESO - Very Large Telescope site, is now in its integration phase. The large number of functions of this complex instrument are fully controlled by a Beckhoff PLC based control electronics architecture. Four small and one large cabinets host the main electronic parts to control all the sensors, motorized stages and other analogue and digital functions of ESPRESSO. The Instrument Control Electronics (ICE) is built following the latest ESO standards and requirements. Two main PLC CPUs are used and are programmed through the TwinCAT Beckhoff dedicated software. The assembly, integration and verification phase of ESPRESSO, due to its distributed nature and different geographical locations of the consortium partners, is quite challenging. After the preliminary assembling and test of the electronic components at the Astronomical Observatory of Trieste and the test of some electronics and software parts at ESO (Garching), the complete system for the control of the four Front End Unit (FEU) arms of ESPRESSO has been fully assembled and tested in Merate (Italy) at the beginning of 2016. After these first tests, the system will be located at the Geneva Observatory (Switzerland) until the Preliminary Acceptance Europe (PAE) and finally shipped to Chile for the commissioning. This paper describes the integration strategy of the ICE workpackage of ESPRESSO, the hardware and software tests that have been performed, with an overall view of the experience gained during these project's phases.

Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Analysis of a Metal-poor Stellar Stream

NASA Astrophysics Data System (ADS)

Roederer, Ian U.; Sneden, Christopher; Thompson, Ian B.; Preston, George W.; Shectman, Stephen A.

2010-03-01

We present the results of a detailed abundance analysis of one of the confirmed building blocks of the Milky Way stellar halo, a kinematically coherent metal-poor stellar stream. We have obtained high-resolution and high signal-to-noise spectra of 12 probable stream members using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory and the 2dCoude spectrograph on the Smith Telescope at McDonald Observatory. We have derived abundances or upper limits for 51 species of 46 elements in each of these stars. The stream members show a range of metallicity (-3.4 < [Fe/H] <-1.5) but are otherwise chemically homogeneous, with the same star-to-star dispersion in [X/Fe] as the rest of the halo. This implies that, in principle, a significant fraction of the Milky Way stellar halo could have formed from accreted systems like the stream. The stream stars show minimal evolution in the α or Fe-group elements over the range of metallicity. This stream is enriched with material produced by the main and weak components of the rapid neutron-capture process and shows no evidence for enrichment by the slow neutron-capture process. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This paper includes data taken at The McDonald Observatory of the University of Texas at Austin.

TCS and peripheral robotization and upgrade on the ESO 1-meter telescope at La Silla Observatory

NASA Astrophysics Data System (ADS)

Ropert, S.; Suc, V.; Jordán, A.; Tala, M.; Liedtke, P.; Royo, S.

2016-07-01

In this work we describe the robotization and upgrade of the ESO 1m telescope located at La Silla Observatory. The ESO 1m telescope was the first telescope installed in La Silla, in 1966. It now hosts as a main instrument the FIber Dual EchellE Optical Spectrograph (FIDEOS), a high resolution spectrograph designed for precise Radial Velocity (RV) measurements on bright stars. In order to meet this project's requirements, the Telescope Control System (TCS) and some of its mechanical peripherals needed to be upgraded. The TCS was also upgraded into a modern and robust software running on a group of single board computers interacting together as a network with the CoolObs TCS developed by ObsTech. One of the particularities of the CoolObs TCS is that it allows to fuse the input signals of 2 encoders per axis in order to achieve high precision and resolution of the tracking with moderate cost encoders. One encoder is installed on axis at the telescope and the other on axis at the motor. The TCS was also integrated with the FIDEOS instrument system so that all the system can be controlled through the same remote user interface. Our modern TCS unit allows the user to run observations remotely through a secured internet web interface, minimizing the need of an on-site observer and opening a new age in robotic astronomy for the ESO 1m telescope.

Development and Flight-testing of Astronomical Instrumentation for Future NASA Astrophysics Missions

NASA Astrophysics Data System (ADS)

France, Kevin

We propose a four year suborbital research program to continue the University of Colorado's efforts in the development and flight testing of instrument designs and critical path technologies for ultraviolet spectroscopy in support of future NASA Explorer, Probe-, and Flagship-class missions. This proposal builds on our existing program of high-resolution spectroscopy for the 100 - 160 nm bandpass with the development of a new high-efficiency imaging spectrograph operating in the same band. The ultimate goal of the University of Colorado ultraviolet rocket program is to develop the technical capabilities to enable a future, highly multiplexed ultraviolet spectrograph (with both high-resolution and imaging spectroscopy modes), e.g., an analog to the successful HST-STIS instrument, with an order-of-magnitude higher efficiency. We do this in the framework of a university led program where undergraduate, graduate, and postdoctoral training is paramount and cutting edge science investigations support our baseline technology development program. In the proposed effort, we will optimize our high-resolution (R > 100,000) echelle spectrograph payload (CHESS) with the first science flight of a new, large-format CCD array provided by our collaborators at JPL and Arizona State University. We will launch CHESS to study our local interstellar environment with spectral resolving power and bandpass that cannot be achieved with any suite of current or planned space missions. In parallel with the proposed science flights of CHESS, we will design, calibrate, and launch a new high-throughput imaging spectrograph (SISTINE); the first sub-arcsecond imaging, medium spectral resolution (R = 10,000), spectrograph ever flown with spectral coverage over the entire 100 - 160 nm bandpass. SISTINE incorporates several novel optical technologies that were highlighted as major hardware drivers for NASA's next large ultraviolet/optical/near-IR observatory by the 2014 Cosmic Origins Technology Report, including advanced mirror coatings with high broadband reflectivity (including > 20% efficiency gains below 115 nm), the first demonstration and flight test of these coatings on a shaped 0.5-meter telescope, and large-format, high-QE photon counting detectors. SISTINE will be launched to study the energetic radiation environment in the habitable zones around nearby low-mass exoplanet host stars, systems that are the top priority in NASA's search for the signatures of biological activity in the coming decade. SISTINE addresses the highest science priority in the 2010 Astronomy and Astrophysics Decadal Survey and is a crucial step towards meeting NASA's technology needs for future space observatories.

Interpretation of two compact planetary nebulae, IC 4997 and NGC 6572, with aid of theoretical models.

PubMed Central

Hyung, S; Aller, L H

1993-01-01

Observations of two dense compact planetary nebulae secured with the Hamilton Echelle spectrograph at Lick Observatory combined with previously published UV spectra secured with the International Ultraviolet Explorer enable us to probe the electron densities and temperatures (plasma diagnostics) and ionic concentrations in these objects. The diagnostic diagrams show that no homogenous model will work for these nebulae. NGC 6572 may consist of an inner torordal ring of density 25,000 atoms/cm3 and an outer conical shell of density 10,000 atoms/cm3. The simplest model of IC 4997 suggests a thick inner shell with a density of about 107 atoms/cm3 and an outer envelope of density 10,000 atoms/cm3. The abundances of all elements heavier than He appear to be less than the solar values in NGC 6572, whereas He, C, N, and O may be more abundant in IC 4997 than in the sun. IC 4997 presents puzzling problems. PMID:11607347

Oxygen and iron abundances in two metal-poor dwarfs

NASA Astrophysics Data System (ADS)

Spiesman, William J.; Wallerstein, George

1991-11-01

Oxygen abundances from the O I line at 6300 A in two metal-poor K dwarfs, HD 25329 and HD 134440, are derived. The spectra were obtained with the KPNO 4-m echelle spectrograph and long camera, yielding a resolution of 32,000 and an S/N of about 125. Model atmospheres with Te of 4770 were appropriate to both stars, whose metallicities were found to be -1.74 and -1.43 for HD 25329 and HD 134440, respectively. These oxygen abundances are 0.3 and 0.4 for the two stars. From the resolution an S/N a 3(sigma) upper limit of 0.8 is derived for each star, which may be combined into an upper limit of O/Fe of 0.6 for a generic K dwarf with Fe/H of 1.6. These values are more in line with O/Fe as seen in similarly metal-poor red giant than those reported in metal-poor subdwarfs by Abia and Rebolo (1989).

A Spectroscopic Survey of Field Red Horizontal-branch Stars

NASA Astrophysics Data System (ADS)

Afşar, Melike; Bozkurt, Zeynep; Böcek Topcu, Gamze; Casetti-Dinescu, Dana I.; Sneden, Christopher; Şehitog̅lu, Gizem

2018-06-01

A metallicity, chemical composition, and kinematic survey has been conducted for a sample of 340 candidate field red horizontal-branch (RHB) stars. Spectra with high resolution and high signal-to-noise ratio were gathered with the McDonald Observatory 2.7 m Tull and the Hobby–Eberly Telescope echelle spectrographs, and were used to determine effective temperatures, surface gravities, microturbulent velocities, [Fe/H] metallicities, and abundance ratios [X/Fe] for seven α and Fe-group species. The derived temperatures and gravities confirm that at least half of the candidates are true RHB stars, with (average) parameters T eff ∼ 5000 K and log g ∼ 2.5. From the α abundances alone, the thin and thick Galactic populations are apparent in our sample. Space motions for 90% of the program stars were computed from Hipparcos and Gaia parallaxes and proper motions. Correlations between chemical compositions and Galactic kinematics clearly indicate the existence of both thin-disk and thick-disk RHB stars.

Minerva-Red: Small Planets Orbiting Small Stars

NASA Astrophysics Data System (ADS)

Blake, Cullen

2018-06-01

Recent results from Kepler and ground-based exoplanet surveys suggest that low-mass stars are host to numerous small planets. Since low-mass stars are intrinsically faint at optical wavelengths, obtaining the Doppler precision necessary to detect these companions remains a challenge for existing instruments. I will describe MINERVA-Red, a project to use a robotic, near-infrared optimized 0.7-meter telescope and a specialized Doppler spectrometer to carry out an intensive, multi-year campaign designed to reveal the planetary systems orbiting some of the closest stars to the Sun. The MINERVA-Red cross-dispersed echelle spectrograph is optimized for the “deep red”, between 800 nm and 900 nm, where the stars that will be targeted are relatively bright. The instrument is very compact and designed for the ultimate in Doppler precision – it uses a single-mode fiber input. I will describe the spectrometer and the status of the MINERVA-Red project, which is expected to begin routine operations at Whipple Observatory on Mt Hopkins, Arizona, in 2018.

Research directed toward improved echelles for the ultraviolet

NASA Technical Reports Server (NTRS)

1977-01-01

Research was undertaken to demonstrate that improved efficiencies for low frequency gratings are obtainable with the careful application of present technology. The motivation for the study was the desire to be assured that the grating-efficiency design goals for potential Space Telescope spectrographs can be achieved. The work was organized to compare gratings made with changes in the three specific parameters: the ruling tool profile, the coating material, and the lubricants used during the ruling process. A series of coatings and test gratings were fabricated and were examined for surface smoothness with a Nomarski Differential Interference Microscope and an electron microscope. Photomicrographs were obtained to show the difference in smoothness of the various coatings and rulings. Efficiency measurements were made for those test rulings that showed good groove characteristics: smoothness, proper ruling depth, and absence of defects. The intuitive feeling that higher grating efficiency should be correlated with the degree of smoothness of both the coating and the grating is supported by the results.

The discovery of the peculiar L dwarf ULAS J222711-004547

NASA Astrophysics Data System (ADS)

Marocco, F.; Day-Jones, A. C.; Jones, H. R. A.; Pinfield, D. J.; Burningham, B.; Zhang, Z. H.

We present the discovery of a very peculiar L dwarf from the UKIDSS Large Area Survey (LAS), ULAS J222711-004547. Its very red infrared colours (MKO J-K = 2.79) make it the reddest brown dwarf discovered so far. The object was discovered as part of a large spectroscopic campaign aimed at constraining the sub-stellar birth rate. We obtained a moderate resolution spectrum of this target using the echelle spectrograph XSHOOTER on VLT/UT2, and classified it as L7pec, confirming its very red nature. We show that applying a simple de-reddening curve to the spectrum of ULAS J222711-004547, this becomes very similar to the spectrum of a L7 spectroscopic standard. Therefore we conclude that the reddening of the spectrum is mostly due to an excess of dust in the photosphere of the object. This new discovery joins the list of unusually red L dwarfs, whose nature is not yet fully understood, and poses a new important challenge to atmospheric modeling of substellar objects.

VizieR Online Data Catalog: The kinematics of the C II λ6578 line in PNe (Richer+, 2017)

NASA Astrophysics Data System (ADS)

Richer, M. G.; Suarez, G.; Lopez, J. A.; Garcia Diaz, M. T.

2018-05-01

All of our observations are drawn from the San Pedro Martir Kinematic Catalogue of Planetary Nebulae (henceforth, SPM Catalogue; Lopez et al. 2012RMxAA..48....3L; http://kincatpn.astrosen.unam.mx/). Most of these spectra were acquired with the Manchester Echelle Spectrograph (MES: Meaburn et al. 1984MNRAS.210..463M, 2003RMxAA..39..185M) attached to the 2.1 m telescope at the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN-SPM). The MES uses interference filters to isolate the spectral order of interest, order 87 in this case, covering approximately the wavelength range 6545-6595 Å and containing the [N II] λλ6548, 6584, He II λ6560 (when present), Hα, and C II λ6578 emission lines. For most of the observations, a 150 μm slit was used, resulting in a spectral resolution of approximately 11 km/s when converted to velocity. (2 data files).

VizieR Online Data Catalog: WOCS. LXXV. Hyades&Praesepe stellar lithium data (Cummings+, 2017)

NASA Astrophysics Data System (ADS)

Cummings, J. D.; Deliyannis, C. P.; Maderak, R. M.; Steinhauer, A.

2018-05-01

The Hyades and Praesepe open star clusters were both observed using the Hydra multi-object spectrograph on the WIYN 3.5-meter telescope using the 316@63.4 echelle grating in order 8 with the X19 filter. The spectra span from 6450 to 6850 Å. All Hyades stars and a majority of Praesepe stars were observed with blue cable, which yielded R~13600. The remaining Praesepe stars were observed with the red cable, which yielded a moderately higher R~17600. The Hyades data were acquired over seven nights from 2009 February 2 to 23. Using two red-cable configurations, we obtained spectra of 34 Praesepe candidate cluster members on 1997 November 16 and 18. Using seven blue cable configurations, we obtained spectra of 66 candidate cluster members during seven nights on 2001 December 2; 2005 May 1 and 2; 2006 January 25 and 26; and 2006 February 2 and 3. (2 data files).

Time variations of oxygen emission lines and solar wind dynamic parameters in low latitude region

NASA Astrophysics Data System (ADS)

Jamlongkul, P.; Wannawichian, S.; Mkrtichian, D.; Sawangwit, U.; A-thano, N.

2017-09-01

Aurora phenomenon is an effect of collision between precipitating particles with gyromotion along Earth’s magnetic field and Earth’s ionospheric atoms or molecules. The particles’ precipitation occurs normally around polar regions. However, some auroral particles can reach lower latitude regions when they are highly energetic. A clear emission from Earth’s aurora is mostly from atomic oxygen. Moreover, the sun’s activities can influence the occurrence of the aurora as well. This work studies time variations of oxygen emission lines and solar wind parameters, simultaneously. The emission’s spectral lines were observed by Medium Resolution Echelle Spectrograph (MRES) along with 2.4 meters diameter telescope at Thai National Observatory, Intanon Mountain, Chiang Mai, Thailand. Oxygen (OI) emission lines were calibrated by Dech-Fits spectra processing program and Dech95 2D image processing program. The correlations between oxygen emission lines and solar wind dynamics will be analyzed. This result could be an evidence of the aurora in low latitude region.

MINERVA-Red: A Census of Planets Orbiting the Nearest Low-mass Stars to the Sun

NASA Astrophysics Data System (ADS)

Blake, Cullen; Johnson, John; Plavchan, Peter; Sliski, David; Wittenmyer, Robert A.; Eastman, Jason D.; Barnes, Stuart

2015-01-01

Recent results from Kepler and ground-based exoplanet surveys suggest that low-mass stars host numerous small planets. Since low-mass stars are intrinsically faint at optical wavelengths, obtaining the Doppler precision necessary to detect these companions remains a challenge for existing instruments. We describe MINERVA-Red, a project to use a dedicated, robotic, near-infrared optimized 0.7 meter telescope and a specialized Doppler spectrometer to carry out an intensive, multi-year campaign designed to reveal the planetary systems orbiting some of the closest stars to the Sun. The MINERVA-Red cross-dispersed echelle spectrograph is optimized for the 'deep red', between 800 nm and 900 nm, where these stars are relatively bright. The instrument is very compact and designed for the ultimate in Doppler precision by using single-mode fiber input. We describe the spectrometer and the status of the MINERVA-Red project, which is expected to begin routine operations at Whipple Observatory on Mt Hopkins, Arizona, in 2015.

First Planet Confirmation with a Dispersed Fixed-Delay Interferometer

NASA Astrophysics Data System (ADS)

van Eyken, J. C.; Ge, J.; Mahadevan, S.; DeWitt, C.

2004-01-01

The Exoplanet Tracker is a prototype of a new type of fiber-fed instrument for performing high-precision relative Doppler measurements to detect extrasolar planets. A combination of Michelson interferometer and medium-resolution spectrograph, this low-cost instrument facilitates radial velocity measurements with high throughput over a small bandwidth (~300 Å) and has the potential to be designed for multiobject operation with moderate bandwidths (~1000 Å). We present the first planet detection with this new type of instrument, a successful confirmation of the well-established planetary companion to 51 Peg, showing an rms precision of 11.5 m s-1 over 5 days. We also show comparison measurements of the radial velocity stable star, η Cas, showing an rms precision of 7.9 m s-1 over 7 days. These new results are starting to approach the precision levels obtained with traditional radial velocity techniques based on cross-dispersed echelles. We anticipate that this new technique could have an important impact in the search for extrasolar planets.

Calibration-free quantitative elemental analysis of meteor plasma using reference laser-induced breakdown spectroscopy of meteorite samples

NASA Astrophysics Data System (ADS)

Ferus, Martin; Koukal, Jakub; Lenža, Libor; Srba, Jiří; Kubelík, Petr; Laitl, Vojtěch; Zanozina, Ekaterina M.; Váňa, Pavel; Kaiserová, Tereza; Knížek, Antonín; Rimmer, Paul; Chatzitheodoridis, Elias; Civiš, Svatopluk

2018-03-01

Aims: We aim to analyse real-time Perseid and Leonid meteor spectra using a novel calibration-free (CF) method, which is usually applied in the laboratory for laser-induced breakdown spectroscopic (LIBS) chemical analysis. Methods: Reference laser ablation spectra of specimens of chondritic meteorites were measured in situ simultaneously with a high-resolution laboratory echelle spectrograph and a spectral camera for meteor observation. Laboratory data were subsequently evaluated via the CF method and compared with real meteor emission spectra. Additionally, spectral features related to airglow plasma were compared with the spectra of laser-induced breakdown and electric discharge in the air. Results: We show that this method can be applied in the evaluation of meteor spectral data observed in real time. Specifically, CF analysis can be used to determine the chemical composition of meteor plasma, which, in the case of the Perseid and Leonid meteors analysed in this study, corresponds to that of the C-group of chondrites.

The interstellar D1 line at high resolution

NASA Technical Reports Server (NTRS)

Hobbs, L. M.; Welty, D. E.

1990-01-01

Observations at a resolving power or a velocity resolution are reported of the interstellar D(sub 1) line of Na I in the spectra of gamma Cas, delta Ori, epsilon Ori, pi Sco, delta Cyg, and alpha Cyg. An echelle grating was used in a double-pass configuration with a CCD detector in the coude spectrograph of the 2.7 m reflector at McDonald Observatory. At least 42 kinematically distinct clouds are detected along the light paths to the five more distant stars, in addition to a single cloud seen toward delta Cyg. The absorption lines arising in 13 of the clouds are sufficiently narrow and unblended to reveal clearly resolved hyperfine structure components split by 1.05 km/s. An additional 13 clouds apparently show comparably narrow, but more strongly blended, lines. For each individual cloud, upper limits T(sub max) and (v sub t)(sub max) on the temperature and the turbulent velocity, respectively, are derived by fitting the observed lines with theoretical absorption profiles.

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron Capture Abundance Gradients

NASA Astrophysics Data System (ADS)

O'Connell, Julia; Frinchaboy, Peter M.; Shetrone, Matthew D.; Melendez, Matthew; Cunha, Katia M. L.; Majewski, Steven R.; Zasowski, Gail; APOGEE Team

2017-01-01

The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity, and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron-capture abundance gradients using 30+ clusters, within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron CaptureAbundance Gradients

NASA Astrophysics Data System (ADS)

O'Connell, Julia; Frinchaboy, Peter M.; Shetrone, Matthew D.; Melendez, Matthew; Cunha, Katia; Majewski, Steven R.; Zasowski, Gail; APOGEE Team

2017-06-01

The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron capture abundance gradients using 30+ clusters, within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

PUCHEROS: a cost-effective solution for high-resolution spectroscopy with small telescopes

NASA Astrophysics Data System (ADS)

Vanzi, L.; Chacon, J.; Helminiak, K. G.; Baffico, M.; Rivinius, T.; Štefl, S.; Baade, D.; Avila, G.; Guirao, C.

2012-08-01

We present PUCHEROS, the high-resolution echelle spectrograph, developed at the Center of Astro-Engineering of Pontificia Universidad Catolica de Chile to provide an effective tool for research and teaching of astronomy. The instrument is fed by a single-channel optical fibre and it covers the visible range from 390 to 730 nm in one shot, reaching a spectral resolution of about 20 000. In the era of extremely large telescopes our instrument aims to exploit the capabilities offered by small telescopes in a cost-effective way, covering the observing needs of a community of astronomers, in Chile and elsewhere, which do not necessarily need large collecting areas for their research. In particular the instrument is well suited for long-term spectroscopic monitoring of bright variable and transient targets down to a V magnitude of about 10. We describe the instrument and present a number of text case examples of observations obtained during commissioning and early science.

Chromospheric Activity of HAT-P-11: An Unusually Active Planet-hosting K Star

NASA Astrophysics Data System (ADS)

Morris, Brett M.; Hawley, Suzanne L.; Hebb, Leslie; Sakari, Charli; Davenport, James. R. A.; Isaacson, Howard; Howard, Andrew W.; Montet, Benjamin T.; Agol, Eric

2017-10-01

Kepler photometry of the hot Neptune host star HAT-P-11 suggests that its spot latitude distribution is comparable to the Sun’s near solar maximum. We search for evidence of an activity cycle in the Ca II H & K chromospheric emission S-index with archival Keck/HIRES spectra and observations from the echelle spectrograph on the Astrophysical Research Consortium 3.5 m Telescope at Apache Point Observatory. The chromospheric emission of HAT-P-11 is consistent with an ≳ 10 year activity cycle, which plateaued near maximum during the Kepler mission. In the cycle that we observed, the star seemed to spend more time near active maximum than minimum. We compare the {log}{R}{HK}{\\prime } normalized chromospheric emission index of HAT-P-11 with other stars. HAT-P-11 has unusually strong chromospheric emission compared to planet-hosting stars of similar effective temperature and rotation period, perhaps due to tides raised by its planet.

An abundance analysis from the STIS-HST UV spectrum of the non-magnetic Bp star HR 6000

NASA Astrophysics Data System (ADS)

Castelli, F.; Cowley, C. R.; Ayres, T. R.; Catanzaro, G.; Leone, F.

2017-05-01

Context. The sharp-line spectrum of the non-magnetic, main-sequence Bp star HR 6000 has peculiarities that distinguish it from those of the HgMn stars with which it is sometimes associated. The position of the star close to the center of the Lupus 3 molecular cloud, whose estimated age is on the order of 9.1 ± 2.1 Myr, has lead to the hypothesis that the anomalous peculiarities of HR 6000 can be explained by the young age of the star. Aims: Observational material from the Hubble Space Telescope (HST) provides the opportunity to extend the abundance analysis previously performed for the optical region and clarify the properties of this remarkable peculiar star. Our aim was to obtain the atmospheric abundances for all the elements observed in a broad region from 1250 to 10 000 Å. Methods: An LTE synthetic spectrum was compared with a high-resolution spectrum observed with the Space Telescope Imaging Spectrograph (STIS) equipment in the 1250-3040 Å interval. Abundances were changed until the synthetic spectrum fit the observed spectrum. The assumed model is an LTE, plane-parallel, line-blanketed ATLAS12 model already used for the abundance analysis of a high-resolution optical spectrum observed at ESO with the Ultraviolet and Visual Echelle Spectrograph (UVES). The stellar parameters are Teff = 13450 K, log g = 4.3, and zero microturbulent velocity. Results: Abundances for 28 elements and 7 upper limits were derived from the ultraviolet spectrum. Adding results from previous work, we have now quantitative results for 37 elements, some of which show striking contrasts with those of a broad sample of HgMn stars. The analysis has pointed out numerous abundance anomalies, such as ionization anomalies and line-to-line variation in the derived abundances, in particular for silicon. The inferred discrepancies could be explained by non-LTE effects and with the occurrence of diffusion and vertical abundance stratification. In the framework of the last hypothesis, we obtained, by means of trial and error, empirical step functions of abundance versus optical depth log (τ5000) for carbon, nitrogen, silicon, manganese, and gold, while we failed to find such a function for phosphorous. The poor results for carbon, and mostly for phosphorus, suggest the possible importance in this star of NLTE effects to be investigated in future works.

Nebular and auroral emission lines of [Cl iii] in the optical spectra of planetary nebulae

PubMed Central

Keenan, Francis P.; Aller, Lawrence H.; Ramsbottom, Catherine A.; Bell, Kenneth L.; Crawford, Fergal L.; Hyung, Siek

2000-01-01

Electron impact excitation rates in Cl III, recently determined with the R-matrix code, are used to calculate electron temperature (Te) and density (Ne) emission line ratios involving both the nebular (5517.7, 5537.9 Å) and auroral (8433.9, 8480.9, 8500.0 Å) transitions. A comparison of these results with observational data for a sample of planetary nebulae, obtained with the Hamilton Echelle Spectrograph on the 3-m Shane Telescope, reveals that the R1 = I(5518 Å)/I(5538 Å) intensity ratio provides estimates of Ne in excellent agreement with the values derived from other line ratios in the echelle spectra. This agreement indicates that R1 is a reliable density diagnostic for planetary nebulae, and it also provides observational support for the accuracy of the atomic data adopted in the line ratio calculations. However the [Cl iii] 8433.9 Å line is found to be frequently blended with a weak telluric emission feature, although in those instances when the [Cl iii] intensity may be reliably measured, it provides accurate determinations of Te when ratioed against the sum of the 5518 and 5538 Å line fluxes. Similarly, the 8500.0 Å line, previously believed to be free of contamination by the Earth's atmosphere, is also shown to be generally blended with a weak telluric emission feature. The [Cl iii] transition at 8480.9 Å is found to be blended with the He i 8480.7 Å line, except in planetary nebulae that show a relatively weak He i spectrum, where it also provides reliable estimates of Te when ratioed against the nebular lines. Finally, the diagnostic potential of the near-UV [Cl iii] lines at 3344 and 3354 Å is briefly discussed. PMID:10759562

Major and minor oxide and trace element determination in silicate rocks by direct current plasma optical emission echelle spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bankston, D.C.; Humphris, S.E.; Thompson, G.

1979-07-01

A technique for the determination of major concentrations of SiO/sub 2/, Al/sub 2/O/sub 3/, Fe/sub 2/O/sub 3/, MgO, CaO, Na/sub 2/O, and K/sub 2/O, minor levels of TiO/sub 2/, P/sub 2/O/sub 5/, and MnO, and trace concentrations of Ba, Cr, Cu, Ni, Sr, V, and Zn, in semi-microsamples 200 mg) of powdered whole rock, is described. Chemically diverse standard reference rocks are used both for calibration and assessment of accuracy. A lithium metaborate fusion melt of each standard or sample is dissolved in dilute HNO/sub 3/ containing Cs/sup +/ at a level of 0.2% (w/v). The resulting solution is usedmore » to perform all analyses except those for Na/sub 2/O and K/sub 2/O, which are determined in a portion of the original sample solution wherein the Cs/sup +/ concentration has been raised to 0.32% (w/v). Analyses of both portions of each sample solution are performed using an optical emission spectrometer/spectrograph equipped with an echelle monochromator and a dc argon plasma excitation source. Trace element detection limits ranged from 2 ppM for Cu to 15 ppM for Zn. A study of precision based on replicate determinations in three splits of the proposed USGS reference basalt BHVO-1 yielded the following results: (1) For analyses of the major and minor oxide constituents, values of the percent relative standard deviation (RSD) ranged from 1 for CaO, to 21 for P/sub 2/O/sub 5/. 2) For trace element determinations, values of the RSD ranged from 2 for Cu, to 19 for Zn. 2 figures, 11 tables.« less

The EDIBLES survey II. The detectability of C60+ bands

NASA Astrophysics Data System (ADS)

Lallement, R.; Cox, N. L. J.; Cami, J.; Smoker, J.; Fahrang, A.; Elyajouri, M.; Cordiner, M. A.; Linnartz, H.; Smith, K. T.; Ehrenfreund, P.; Foing, B. H.

2018-06-01

Gas phase spectroscopic laboratory experiments for the buckminsterfullerene cation C60+ have resulted in accurate rest wavelengths for five C60+ transitions that have been compared with diffuse interstellar bands (DIBs) in the near infra-red. Detecting these in astronomical spectra is difficult because of the strong contamination of ground-based spectra by atmospheric water vapor, to the presence of weak and shallow stellar lines and/or blending with other weak DIBs. The detection of the two strong bands has been claimed by several teams, and the three additional and weaker bands have been detected in a few sources. Certain recent papers have argued against the identification of C60+ based on spectral analyses claiming (i) a large variation in the ratio of the equivalent widths of the 9632 and 9577 Å bands, (ii) a large redshift of the 9632 Å band for the Orion star HD 37022, and (iii) the non-detection of the weaker 9428 Å DIB. Here we address these three points: (i) We show that the model stellar line correction for the 9632 Å DIB overestimates the difference between the strengths of the lines in giant and dwarf star spectra, casting doubts on the conclusions about the ratio variability. (ii) Using high quality stellar spectra from the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES), recorded with the ESO/Paranal Ultraviolet Echelle Spectrograph (UVES) in about the same atmospheric conditions, we find no wavelength shift in the 9632 Å band toward HD 37022. (iii) Using EDIBLES spectra and data from the Echelle SpectroPolarimetric Device for the Observation of Stars (ESPaDOnS) at CFHT we show that the presence of a weak 9428 Å band cannot be ruled out, even in the same observations that a previous study claimed it was not present.

Post-Servicing Mission 4 Flux Calibration of the STIS Echelle Modes

NASA Astrophysics Data System (ADS)

Azalee Bostroem, K.; Aloisi, A.; Proffitt, C.; Osten, R.; Bohlin, R.

2011-01-01

STIS echelle modes show a wavelength-dependent decline in sensitivity with time. While this trend is observed in all STIS spectroscopic modes, the echelle sensitivity is further affected by a time-dependent shift in the blaze function. To improve the echelle flux calibration, new baselines for the echelle sensitivities are derived from post-Servicing Mission 4 (SM4) observations of the Hubble Space Telescope standard star G191-B2B. We present how these baseline sensitivities compare to pre-failure trends. Specifically, where the new results differ from expectations and discuss anomalous results found in E140H monitoring observations are highlighted.

VizieR Online Data Catalog: Photometry and spectroscopy of V501 Mon (Torres+, 2015)

NASA Astrophysics Data System (ADS)

Torres, G.; Lacy, C. H. S.; Pavlovski, K.; Fekel, F. C.; Muterspaugh, M. W.

2016-06-01

Spectroscopic observations of V501 Mon were carried out with three different instruments. They began at the Harvard-Smithsonian Center for Astrophysics (CfA) in 2005 November, using the now decommissioned Digital Speedometer (DS) mounted on the 1.5m Tillinghast reflector at the Fred L. Whipple Observatory on Mount Hopkins (AZ). Seven spectra were recorded through 2009 March with an intensified photon-counting Reticon detector, and cover a narrow span of 45Å centered at 5190Å (MgIb triplet). The resolving power of this instrument was R~35000, and the signal-to-noise ratios of the spectra range from 13 to 22 per resolution element of 8.5km/s. Thirty seven additional spectra were gathered from 2009 November to 2015 February with the Tillinghast Reflector Echelle Spectrograph (TRES) on the same telescope. This bench-mounted, fiber-fed instrument provides a resolving power of R~44000 in 51 orders over the wavelength span 3900-9100Å. The signal-to-noise ratios of the 37 spectra range from 8 to 56 per resolution element of 6.8km/s. The heliocentric velocities we obtained from the DS and TRES spectra are listed in Table2. Between 2011 October and 2015 February we also obtained 57 usable spectra of V501 Mon with the Tennessee State University 2m Automatic Spectroscopic Telescope (AST) and a fiber-fed echelle spectrograph at Fairborn Observatory in southeast Arizona. The detector for these observations was a Fairchild 486 CCD, with 15μm pixels in a 4096*4096 format. The spectrograms have 48 orders ranging from 3800 to 8260Å. Because of the faintness of V501 Mon (V=12.32), we used a fiber that produced a spectral resolution of 0.4Å, corresponding to a resolving power of 15000 at 6000Å. Our spectra have typical signal-to-noise ratios per resolution element of 40 at 6000Å. We list the final values in Table3. An extensive program of CCD photometry was carried out using the NFO WebScope ear Silver City, New Mexico, for the purpose of gathering an accurate V-band light curve of V501 Mon for analysis. A total of 6729 images were obtained over 281 nights between 2005 January and February. Table5 lists these differential photometric measurements. Measurements of the times of eclipse for V501 Mon collected from the literature are listed in Table1, and cover approximately seven decades. Abundances for individual elements are listed in Table7. (5 data files).

The crowded magnetosphere of the post-common-envelope binary QS Virginis

NASA Astrophysics Data System (ADS)

Parsons, S. G.; Hill, C. A.; Marsh, T. R.; Gänsicke, B. T.; Watson, C. A.; Steeghs, D.; Dhillon, V. S.; Littlefair, S. P.; Copperwheat, C. M.; Schreiber, M. R.; Zorotovic, M.

2016-05-01

We present high-speed photometry and high-resolution spectroscopy of the eclipsing post-common-envelope binary QS Virginis (QS Vir). Our Ultraviolet and Visual Echelle Spectrograph (UVES) spectra span multiple orbits over more than a year and reveal the presence of several large prominences passing in front of both the M star and its white dwarf companion, allowing us to triangulate their positions. Despite showing small variations on a time-scale of days, they persist for more than a year and may last decades. One large prominence extends almost three stellar radii from the M star. Roche tomography reveals that the M star is heavily spotted and that these spots are long-lived and in relatively fixed locations, preferentially found on the hemisphere facing the white dwarf. We also determine precise binary and physical parameters for the system. We find that the 14 220 ± 350 K white dwarf is relatively massive, 0.782 ± 0.013 M⊙, and has a radius of 0.010 68 ± 0.000 07 R⊙, consistent with evolutionary models. The tidally distorted M star has a mass of 0.382 ± 0.006 M⊙ and a radius of 0.381 ± 0.003 R⊙, also consistent with evolutionary models. We find that the magnesium absorption line from the white dwarf is broader than expected. This could be due to rotation (implying a spin period of only ˜700 s), or due to a weak (˜100 kG) magnetic field, we favour the latter interpretation. Since the M star's radius is still within its Roche lobe and there is no evidence that it is overinflated, we conclude that QS Vir is most likely a pre-cataclysmic binary just about to become semidetached.

The GTC exoplanet transit spectroscopy survey. V. A spectrally-resolved Rayleigh scattering slope in GJ 3470b

NASA Astrophysics Data System (ADS)

Chen, G.; Guenther, E. W.; Pallé, E.; Nortmann, L.; Nowak, G.; Kunz, S.; Parviainen, H.; Murgas, F.

2017-04-01

Aims: As a sub-Uranus-mass low-density planet, GJ 3470b has been found to show a flat featureless transmission spectrum in the infrared and a tentative Rayleigh scattering slope in the optical. We conducted an optical transmission spectroscopy project to assess the impacts of stellar activity and to determine whether or not GJ 3470b hosts a hydrogen-rich gas envelop. Methods: We observed three transits with the low-resolution Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy (OSIRIS) at the 10.4 m Gran Telescopio Canarias, and one transit with the high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) at the 8.2 m Very Large Telescope. Results: From the high-resolution data, we find that the difference of the Ca II H+K lines in- and out-of-transit is only 0.67 ± 0.22%, and determine a magnetic filling factor of about 10-15%. From the low-resolution data, we present the first optical transmission spectrum in the 435-755 nm band, which shows a slope consistent with Rayleigh scattering. Conclusions: After exploring the potential impacts of stellar activity in our observations, we confirm that Rayleigh scattering in an extended hydrogen-helium atmosphere is currently the best explanation. Further high-precision observations that simultaneously cover optical and infrared bands are required to answer whether or not clouds and hazes exist at high-altitude. Based on observations made with the Gran Telescopio Canarias (GTC), at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma, as well as observations obtained at the European Southern Observatory at Paranal, Chile in program 096.C-0258(A).

Neutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry★†

NASA Astrophysics Data System (ADS)

Madonna, S.; García-Rojas, J.; Sterling, N. C.; Delgado-Inglada, G.; Mesa-Delgado, A.; Luridiana, V.; Roederer, I. U.; Mashburn, A. L.

2017-10-01

We analyse the chemical composition of the planetary nebula (PN) NGC 5315, through high-resolution (R ˜ 40000) optical spectroscopy with Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope, and medium-resolution (R ˜ 4800) near-infrared spectroscopy with Folded-port InfraRed Echellette at Magellan Baade Telescope, covering a wide spectral range from 0.31 to 2.50 μm. The main aim of this work is to investigate neutron (n)-capture element abundances to study the operation of the slow n-capture ('s-process') in the asymptotic giant branch (AGB) progenitor of NGC 5315. We detect more than 700 emission lines, including ions of the n-capture elements Se, Kr, Xe and possibly Br. We compute physical conditions from a large number of diagnostic line ratios, and derive ionic abundances for species with available atomic data. The total abundances are computed using recent ionization correction factors (ICFs) or by summing ionic abundances. Total abundances of common elements are in good agreement with previous work on this object. Based on our abundance analysis of NGC 5315, including the lack of s-process enrichment, we speculate that the most probable evolutionary scenario is that the progenitor star is in a binary system as hinted at by radial velocity studies, and interactions with its companion truncated the AGB before s-process enrichment could occur. However there are other two possible scenarios for its evolution, that cannot be ruled out: (I) the progenitor is a low-mass single star that did not undergo third dredge-up; (II) the progenitor star of NGC 5315 had an initial mass of 3-5 M⊙, and any s-process enhancements were heavily diluted by the massive envelope during the AGB phase.

Pressure shifts and abundance gradients in the atmosphere of the DAZ white dwarf GALEX J193156.8+011745

NASA Astrophysics Data System (ADS)

Vennes, S.; Kawka, A.; Németh, P.

2011-06-01

We present a detailed model atmosphere analysis of high-dispersion and high signal-to-noise ratio spectra of the heavily polluted DAZ white dwarf GALEX J1931+0117. The spectra obtained with the Very Large Telescope (VLT)-Kueyen/UV-Visual Echelle Spectrograph show several well-resolved Si II spectral lines enabling a study of pressure effects on line profiles. We observed large Stark shifts in silicon lines in agreement with theoretical predictions and laboratory measurements. Taking into account Stark shifts in the calculation of synthetic spectra, we reduced the scatter in individual line radial velocity measurements from ˜3 to ≲1 km s-1. We present revised abundances of O, Mg, Si, Ca and Fe based on a critical review of line-broadening parameters and oscillator strengths. The new measurements are generally in agreement with our previous analysis with the exception of magnesium with a revised abundance of a factor of 2 lower than previously estimated. The magnesium, silicon and iron abundances exceed solar abundances, but the oxygen and calcium abundances are below solar. Also, we compared the observed line profiles to synthetic spectra computed with variable accretion rates and vertical abundance distributions assuming diffusive steady state. The inferred accretion rates vary from ? for calcium to 2 × 109 g s-1 for oxygen. We find that the accretion flow must be oxygen rich while being deficient in calcium relative to solar abundances. The lack of radial velocity variations between two measurement epochs suggests that GALEX J1931+0117 is probably not in a close binary and that the source of the accreted material resides in a debris disc. Based on observations made with European Southern Observatory (ESO) telescopes at the La Silla Paranal Observatory under programme 283.D-5060.

VizieR Online Data Catalog: Radial velocities in M67. I. 1278 candidate members (Geller+, 2015)

NASA Astrophysics Data System (ADS)

Geller, A. M.; Latham, D. W.; Mathieu, R. D.

2015-10-01

This is the first in a series of papers studying the dynamical state of the old open cluster M67 through precise radial velocities. This is also the paper LXVII of the WIYN Open Cluster Study. Our radial velocity survey of M67 began as part of the dissertation work of Mathieu (1983PhDT.........8M), taking advantage of the CfA Digital Speedometers (DS). Three nearly identical instruments were used, initially on the MMT (from HJD2445337 to HJD2450830) and 1.5m Tillinghast Reflector (from HJD2444184 to HJD2454958) at the Fred Lawrence Whipple Observatory on Mount Hopins, Arizona, and then later on the 1.5m Wyeth Reflector (from HJD2445722 to HJD2453433) at the Oak Ridge Observatory in the Town of Harvard, Massachusetts. Subsequently the M67 target samples were expanded several times. Radial velocities measurements from other programs were integrated into the database, and our observational facilities were extended to include Hydra Multi-Object Spectrograph (MOS) at the WIYN Observatory (from HJD2453386 to HJD2456709) and the new Tillinghast Reflector Echelle Spectrograph (TRES) on the Tillinghast Reflector (from HJD2455143 to HJD2456801). Details about the telescopes, observing procedures, and data reductions of spectra obtained with the CfA DS can be found in Latham (1985srv..conf...21L, 1992ASPC...32..110L). The corresponding information for spectra obtained with Hydra at the WIYN Observatory can be found in Geller et al. 2008 (cat. J/AJ/135/2264), Geller et al. 2010 (cat. J/AJ/139/1383) and Hole et al. (2009). TRES is a stabilized fiber-fed echelle spectrograph with a CCD detector and resolution of 44000. The initial CfA sample was defined in 1982. The last surviving CfA Digital Speedometer, on the 1.5m Tillinghast Reflector, was retired in the summer of 2009. Over the following five observing seasons, TRES was used to continue the radial velocity observations of targets (mostly binaries) from both the CfA and the WIYN samples. Importantly, Roger Griffin and James Gunn also had a radial velocity program for M67 from 1971 to 1982 at the Palomar Hale 5m telescope (from HJD2440952 to HJD2445297), which they supplemented with contemporaneous observations obtained with the CORAVEL instrument (from HJD2444340 to HJD2446413) at Haute Provence for five of the binaries. Their target sample was very similar to our initial sample. We refer to the target stars and the measurements taken at all telescope/instrument pairs except WIYN/Hydra as the CfA sample and data. As of 2015 February, there are 447 stars in the CfA sample. WIYN observations of M67 began on 2005 January 15 as part of the WIYN Open Cluster Study (WOCS; Mathieu, 2000ASPC..198..517M). In total there are 1278 stars within the WIYN stellar sample; 382 of these stars are also in the CfA stellar sample. (1 data file).

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 1, data analysis and results

NASA Astrophysics Data System (ADS)

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward H.; Sirk, Martin; Muirhead, Philip S.; Muterspaugh, Matthew W.; Lloyd, James P.; Ishikawa, Yuzo; McDonald, Eliza A.; Shourt, William V.; Vanderburg, Andrew M.

2016-04-01

High-resolution broadband spectroscopy at near-infrared wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar. Observations of stars were performed with the "TEDI" interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec near-infrared echelle spectrograph. These are the first multidelay EDI demonstrations on starlight, as earlier measurements used a single delay or laboratory sources. We demonstrate very high (10×) resolution boost, from original 2700 to 27,000 with current set of delays (up to 3 cm), well beyond the classical limits enforced by the slit width and detector pixel Nyquist limit. Significantly, the EDI used with multiple delays rather than a single delay as used previously yields an order of magnitude or more improvement in the stability against native spectrograph point spread function (PSF) drifts along the dispersion direction. We observe a dramatic (20×) reduction in sensitivity to PSF shift using our standard processing. A recently realized method of further reducing the PSF shift sensitivity to zero is described theoretically and demonstrated in a simple simulation which produces a 350× times reduction. We demonstrate superb rejection of fixed pattern noise due to bad detector pixels-EDI only responds to changes in pixel intensity synchronous to applied dithering. This part 1 describes data analysis, results, and instrument noise. A section on theoretical photon limited sensitivity is in a companion paper, part 2.

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 1, data analysis and results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward H.

High-resolution broadband spectroscopy at near-infrared wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar. Observations of stars were performed with the “TEDI” interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec near-infrared echelle spectrograph. These are the first multidelay EDI demonstrations on starlight, as earlier measurements used a single delay or laboratory sources. We demonstrate very high (10×) resolution boost, from original 2700 to 27,000 with current set of delays (up to 3 cm), well beyond the classical limits enforced bymore » the slit width and detector pixel Nyquist limit. Significantly, the EDI used with multiple delays rather than a single delay as used previously yields an order of magnitude or more improvement in the stability against native spectrograph point spread function (PSF) drifts along the dispersion direction. We observe a dramatic (20×) reduction in sensitivity to PSF shift using our standard processing. A recently realized method of further reducing the PSF shift sensitivity to zero is described theoretically and demonstrated in a simple simulation which produces a 350× times reduction. We demonstrate superb rejection of fixed pattern noise due to bad detector pixels—EDI only responds to changes in pixel intensity synchronous to applied dithering. This part 1 describes data analysis, results, and instrument noise. Lastly, a section on theoretical photon limited sensitivity is in a companion paper, part 2.« less

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 1, data analysis and results

DOE PAGES

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward H.; ...

2016-05-27

High-resolution broadband spectroscopy at near-infrared wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar. Observations of stars were performed with the “TEDI” interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec near-infrared echelle spectrograph. These are the first multidelay EDI demonstrations on starlight, as earlier measurements used a single delay or laboratory sources. We demonstrate very high (10×) resolution boost, from original 2700 to 27,000 with current set of delays (up to 3 cm), well beyond the classical limits enforced bymore » the slit width and detector pixel Nyquist limit. Significantly, the EDI used with multiple delays rather than a single delay as used previously yields an order of magnitude or more improvement in the stability against native spectrograph point spread function (PSF) drifts along the dispersion direction. We observe a dramatic (20×) reduction in sensitivity to PSF shift using our standard processing. A recently realized method of further reducing the PSF shift sensitivity to zero is described theoretically and demonstrated in a simple simulation which produces a 350× times reduction. We demonstrate superb rejection of fixed pattern noise due to bad detector pixels—EDI only responds to changes in pixel intensity synchronous to applied dithering. This part 1 describes data analysis, results, and instrument noise. Lastly, a section on theoretical photon limited sensitivity is in a companion paper, part 2.« less

SOFIA science instruments: commissioning, upgrades and future opportunities

NASA Astrophysics Data System (ADS)

Smith, Erin C.; Miles, John W.; Helton, L. Andrew; Sankrit, Ravi; Andersson, B. G.; Becklin, Eric E.; De Buizer, James M.; Dowell, C. D.; Dunham, Edward W.; Güsten, Rolf; Harper, Doyal A.; Herter, Terry L.; Keller, Luke D.; Klein, Randolf; Krabbe, Alfred; Logsdon, Sarah; Marcum, Pamela M.; McLean, Ian S.; Reach, William T.; Richter, Matthew J.; Roellig, Thomas L.; Sandell, Göran; Savage, Maureen L.; Temi, Pasquale; Vacca, William D.; Vaillancourt, John E.; Van Cleve, Jeffrey E.; Young, Erick T.

2014-07-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is the world's largest airborne observatory, featuring a 2.5 meter effective aperture telescope housed in the aft section of a Boeing 747SP aircraft. SOFIA's current instrument suite includes: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), a 5-40 μm dual band imager/grism spectrometer developed at Cornell University; HIPO (High-speed Imaging Photometer for Occultations), a 0.3-1.1μm imager built by Lowell Observatory; GREAT (German Receiver for Astronomy at Terahertz Frequencies), a multichannel heterodyne spectrometer from 60-240 μm, developed by a consortium led by the Max Planck Institute for Radio Astronomy; FLITECAM (First Light Infrared Test Experiment CAMera), a 1-5 μm wide-field imager/grism spectrometer developed at UCLA; FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), a 42-200 μm IFU grating spectrograph completed by University Stuttgart; and EXES (Echelon-Cross-Echelle Spectrograph), a 5-28 μm highresolution spectrometer designed at the University of Texas and being completed by UC Davis and NASA Ames Research Center. HAWC+ (High-resolution Airborne Wideband Camera) is a 50-240 μm imager that was originally developed at the University of Chicago as a first-generation instrument (HAWC), and is being upgraded at JPL to add polarimetry and new detectors developed at Goddard Space Flight Center (GSFC). SOFIA will continually update its instrument suite with new instrumentation, technology demonstration experiments and upgrades to the existing instrument suite. This paper details the current instrument capabilities and status, as well as the plans for future instrumentation.

Software requirements flow-down and preliminary software design for the G-CLEF spectrograph

NASA Astrophysics Data System (ADS)

Evans, Ian N.; Budynkiewicz, Jamie A.; DePonte Evans, Janet; Miller, Joseph B.; Onyuksel, Cem; Paxson, Charles; Plummer, David A.

2016-08-01

The Giant Magellan Telescope (GMT)-Consortium Large Earth Finder (G-CLEF) is a fiber-fed, precision radial velocity (PRV) optical echelle spectrograph that will be the first light instrument on the GMT. The G-CLEF instrument device control subsystem (IDCS) provides software control of the instrument hardware, including the active feedback loops that are required to meet the G-CLEF PRV stability requirements. The IDCS is also tasked with providing operational support packages that include data reduction pipelines and proposal preparation tools. A formal, but ultimately pragmatic approach is being used to establish a complete and correct set of requirements for both the G-CLEF device control and operational support packages. The device control packages must integrate tightly with the state-machine driven software and controls reference architecture designed by the GMT Organization. A model-based systems engineering methodology is being used to develop a preliminary design that meets these requirements. Through this process we have identified some lessons that have general applicability to the development of software for ground-based instrumentation. For example, tasking an individual with overall responsibility for science/software/hardware integration is a key step to ensuring effective integration between these elements. An operational concept document that includes detailed routine and non- routine operational sequences should be prepared in parallel with the hardware design process to tie together these elements and identify any gaps. Appropriate time-phasing of the hardware and software design phases is important, but revisions to driving requirements that impact software requirements and preliminary design are inevitable. Such revisions must be carefully managed to ensure efficient use of resources.

CARMENES science preparation: characterisation of M dwarfs with low-resolution spectroscopy and search for low-mass wide companions to young stars

NASA Astrophysics Data System (ADS)

Alonso-Floriano, F. J.

2015-11-01

This thesis is focused on the study of low-mass objects that can be targets of exoplanet searches with near-infrared spectrographs in general and CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs; see Quirrenbach et al. 2014) in particular. The CARMENES consortium comprises 11 institutions from Germany and Spain that are building a high-resolution spectrograph (R=82,000) with two channels, visible (0.55 - 1.05 um) and infrared (0.95 - 1.7 um), for the 3.5 m Calar Alto telescope. It will observe a sample of 300 M dwarfs in 600 nights of guaranteed time during at least three years, starting in January 2016. The final sample will be chosen from the 2200 M dwarfs included in the CARMENCITA input catalogue. For these stars, we have obtained and collected a large amount of data: spectral types, radial and rotational velocities, photometry in several bands, etc. Part of the e effort of the science preparation necessary for the final selection of targets for CARMENES and other near-infrared spectrographs has been collected in two publications, which are presented in this PhD thesis. In the first publication (Alonso-Floriano et al., 2015A&A...577A.128A), we obtained low-resolution spectra for 753 stars using the CAFOS spectrograph at the 2.2 m Calar Alto telescope. The main goal was to derive accurate spectral types, which are fundamental parameters for the sample selection. We used a grid of 49 standard stars, from spectral types K3V to M8V, together with a double least-square minimisation technique and 31 spectral indices previously defined by other authors. In addition, we quantified the surface gravity, metallicity and chromospheric activity of the sample, in order to detect low-gravity stars (giants and very young), metal-poor and very metal-poor stars (subdwarfs), and very active stars. In the second publication (Alonso-Floriano et al., 2015A&A...583A..85A), we searched for common proper motion companions, especially of low mass, to members of the near young beta Pictoris moving group. First, we compiled a list of 185 members and candidate members to beta Pictoris from 35 representatives studies on this moving group. Next, we used the Aladin and STILTS virtual observatory tools, as well as the PPMXL proper motion and Washington double stars catalogues. The objects that showed similar proper motions to those stars of the sample were targets of an astro-photometric follow-up. The 36 common proper motion companion eventually obtained were subjects of a study of binding energies to determine their physical ligation.

Search for companions in visual binary systems using precise radial-velocity measurements

NASA Astrophysics Data System (ADS)

Katoh, Noriyuki; Itoh, Yoichi; Sato, Bun'ei

2018-05-01

The frequency of triple and quadruple systems is considered to be high in the early phase of star formation. Some multiple systems decay in the pre-main-sequence phase. The multiplicity of main-sequence stars provides clues about the evolution of binary systems. This work searched for companions of five components of visual binary systems using precise radial-velocity measurements. Their radial velocities were monitored from 2007 to 2012 using the HIgh Dispersion Echelle Spectrograph (HIDES) installed on the Okayama Astrophysical Observatory (OAO) 1.88 m reflector. In combination with previous work, this work searched for companions with an orbital period of less than 9 yr for the five bodies. We found periodic variations in the radial velocities for ADS 6190 A and BDS 10966A. The radial velocities of ADS 7311 A, 31 Dra A, and 31 Dra B show significant trends. ADS 6190 A is an SB1 binary with an orbital period of 366.2 d. The minimum mass of the secondary star is 0.5^{+0.7}_{-0.2} M_{⊙}. The radial velocity of ADS 7311 A was monitored for an observational span of 3200 d. We rejected a planetary-mass companion as the cause of a decreasing trend in the radial velocity of ADS 7311 A. This work confirmed that the periodic variation in the radial velocity of BDS 10966 A is 771.1 d. Bisector analysis did not reveal a correlation between the asymmetry of a spectral line and the radial velocity of BDS 10966 A. We rejected nonradial oscillation of the photosphere as the source of the radial velocity variation. The variation may be caused by the rotational modulation owing to surface inhomogeneity. The orbital elements of 31 Dra A derived in this paper are consistent with those in a previous paper. 31 Dra A system is an SB1 binary with a minimum mass ratio of 0.30 ± 0.08. 31 Dra B exhibits a periodic variation in radial velocity. The orbital elements derived in this work are consistent with those reported previously by others. The variation is caused by a circumstellar planet.

Velocity Distributions of Interplanetary Dust Derived from Astronomical Sky Spectra

NASA Astrophysics Data System (ADS)

Huestis, D. L.; Ali, S.; Cosby, P. C.; Slanger, T. G.

2001-11-01

Characterization of interplanetary dust is important for understanding the creation by accretion of planets and moons, the development of planetary atmospheres, and, potentially, for the initiation of prebiotic chemistry. The recent COBE mission has provided a profile in ecliptic coordinates of the distribution of interplanetary dust particles through their thermal infrared emission. Additional information about interplanetary dust can be extracted from its visible spectrum of scattered sunlight, called Zodiacal Light. Night sky spectra taken at large-aperture telescopes using high-resolution echelle spectrographs reveal Fraunhofer absorption features in the Zodiacal Light spectrum of scattered sunlight, a nuisance in subtraction from the spectrum of the extraterrestrial object under investigation. We are analyzing the intensity modulations and Doppler shifts of solar Fraunhofer absorption lines in the Zodiacal Light component of sky spectra, donated by collaborating astronomers using Keck/HIRES and other high-performance astronomical facilities. Our objectives include velocity distributions of interplanetary dust and improved separation of terrestrial and extraterrestrial sources in sky spectra. Participation of S. Ali was made possible by a grant from the NSF Physics Research Experiences for Undergraduates (REU) program.

A study of mass loss from the mid-ultraviolet spectrum of Alpha Cygni /A2 Ia/, Beta Orionis /B8 Ia/, and Eta Leonis /A0 Ib/

NASA Technical Reports Server (NTRS)

Lamers, H. J. G. L. M.; Stalio, R.; Kondo, Y.

1978-01-01

Results are presented for a study of mass loss from A and late-B supergiants based on high-resolution mid-UV spectra obtained with the echelle spectrograph of the Balloon-borne Ultraviolet Stellar Spectrometer. Spectra of Alpha Cyg, Beta Ori, Eta Leo, and Alpha Lyr are compared in selected wavelength regions; particular attention is given to previous observations of each star, the Mg II and Fe II resonance lines, lines due to other ions, and evidence for mass ejection. The results indicate that mass loss from late-B and A supergiants is variable, that a considerable fraction of envelope material is ejected in 'puffs', and that the puffs may be due to photospheric instabilities. A mass-loss rate of about 1 hundred-millionth of a solar mass per year is derived for Alpha Cyg and shown to be two orders of magnitude smaller than the value determined from the observed IR excess. This discrepancy is attributed to excess ionization in the envelope.

A testbed for simultaneous measurement of fiber near and far-field for the evaluation of fiber scrambling properties

NASA Astrophysics Data System (ADS)

Feger, Tobias; Brucalassi, Anna; Grupp, Frank U.; Lang-Bardl, Florian; Holzwarth, Ronald; Hopp, Ulrich; Bender, Ralf

2012-09-01

To improve our understanding of fiber scrambling properties a test bed where fiber near-field and far-field can be measured simultaneously is described. A variety of measurements has been conducted with a selection of fibers from different vendors, including state-of-the-art octagonal and hexagonal fibers. After characterization of the test bench with respect to stability and resolution, scrambling measurements have been conducted using LEDs with central wavelengths ranging between 465-635 nm. The dependence on wavelength regarding to photometrical scrambling has been initially demonstrated. Moreover, two mechanical combined fiber cables have been analyzed that were made from octagonal-circular and hexagonal-octagonal fiber sections. In this context an apparatus for focal ratio degradation (FRD) measurements was assembled to compare different shaped fibers and fiber combinations. Finally, all these preliminary investigations will help in choosing a fiber with good radial scrambling performance for the next generation fiber-link of the fiber optic coupled Cassegrain echelle spectrograph FOCES intended to be operated at the 2.0m Fraunhofer Telescope at the Wendelstein Observatory.

The height variation of supergranular velocity fields determined from simultaneous OSO 8 satellite and ground-based observations

NASA Technical Reports Server (NTRS)

November, L. J.; Toomre, J.; Gebbie, K. B.; Simon, G. W.

1979-01-01

Results are reported for simultaneous satellite and ground-based observations of supergranular velocities in the sun, which were made using a UV spectrometer aboard OSO 8 and a diode-array instrument operating at the exit slit of an echelle spectrograph attached to a vacuum tower telescope. Observations of the steady Doppler velocities seen toward the limb in the middle chromosphere and the photosphere are compared; the observed spectral lines of Si II at 1817 A and Fe I at 5576 A are found to differ in height of formation by about 1400 km. The results show that supergranular motions are able to penetrate at least 11 density scale heights into the middle chromosphere, that the patterns of motion correlate well with the cellular structure seen in the photosphere, and that the motion increases from about 800 m/s in the photosphere to at least 3000 m/s in the middle chromosphere. These observations imply that supergranular velocities should be evident in the transition region and that strong horizontal shear layers in supergranulation should produce turbulence and internal gravity waves.

A new Böhm-Vitense gap in the temperature range 5560 to 5610 K in the main sequence hm-Vitense gap in the main sequence

NASA Astrophysics Data System (ADS)

Kovtyukh, V. V.; Soubiran, C.; Belik, S. I.

2004-12-01

Highly precise temperatures (σ = 10-15 K) have been determined from line depth ratios for a set of 248 F-K field dwarfs of about solar metallicity (-0.5 < [Fe/H] < +0.4), based on high resolution (R=42 000), high S/N echelle spectra. A new gap has been discovered in the distribution of stars on the Main Sequence in the temperature range 5560 to 5610 K. This gap coincides with a jump in the microturbulent velocity Vt and the well-known Li depression near 5600 K in field dwarfs and open clusters. As the principal cause of the observed discontinuities in stellar properties we propose the penetration of the convective zone into the inner layers of stars slightly less massive than the Sun and related to it, a change in the temperature gradient. Based on spectra collected with the ELODIE spectrograph at the 1.93-m telescope of the Observatoire de Haute-Provence (France). Full Table 1 is only available in electronic form at http://www.edpsciences.org

The variations of oxygen emissions in corresponding to Earth's aurora in low latitude region under influence of solar wind dynamics

NASA Astrophysics Data System (ADS)

Jamlongkul, P.; Wannawichian, S.

2017-12-01

Earth's aurora in low latitude region was studied via time variations of oxygen emission spectra, simultaneously with solar wind data. The behavior of spectrum intensity, in corresponding with solar wind condition, could be a trace of aurora in low latitude region including some effects of high energetic auroral particles. Oxygen emission spectral lines were observed by Medium Resolution Echelle Spectrograph (MRES) at 2.4-m diameter telescope at Thai National Observatory, Inthanon Mountain, Chiang Mai, Thailand, during 1-5 LT on 5 and 6 February 2017. The observed spectral lines were calibrated via Dech95 - 2D image processing program and Dech-Fits spectra processing program for spectrum image processing and spectrum wavelength calibration, respectively. The variations of observed intensities each day were compared with solar wind parameters, which are magnitude of IMF (|BIMF|) including IMF in RTN coordinate (BR, BT, BN), ion density (ρ), plasma flow pressure (P), and speed (v). The correlation coefficients between oxygen spectral emissions and different solar wind parameters were found to vary in both positive and negative behaviors.

VizieR Online Data Catalog: Radial velocities and BVIc LCs of the EB* CU Cnc (Wilson+, 2017)

NASA Astrophysics Data System (ADS)

Wilson, R. E.; Pilachowski, C. A.; Terrell, D.

2017-09-01

Infrared spectra of CU Cnc were obtained with the Phoenix spectrometer on the 2.1 and 4m telescopes at Kitt Peak National Observatory in 2013 December, and 2014 January and February (λc=2.33um, R=50000). The primary star is defined here as the slightly hotter and more massive one that is eclipsed near zero phase according to the ephemeris. High-resolution optical spectra of CU Cnc were obtained for estimation of elemental abundances. An 1800s observation was obtained on 2014 May 17 with the Astrophysical Research Consortium (ARC) echelle spectrograph (ARCES) at a phase near quadrature. A second spectrum was obtained with the same instrument on 2015 November 21 with an exposure time of 3600s at a phase near conjunction. The spectra cover the wavelength range from 3500 to 10000Å and resolving power is about 31500. The CU Cnc field was observed at the Sonoita Research Observatory with Johnson-Cousins BVIC and SDSS g'r'i' filters. (2 data files).

A Study of Rovibrational H2O, OH, and CO emission from the Herbig Ae/Be star HD 250550

NASA Astrophysics Data System (ADS)

Leiendecker, Harrison; Brittain, Sean; Jensen, Stanley; Najita, Joan R.; Carr, John S.

2018-01-01

We present high-resolution spectroscopy (R∼75,000) of the Herbig Ae/Be star HD 250550. The L-band spectroscopy was obtained with the infrared echelle spectrograph (iSHELL) from The NASA Infrared Telescope Facility. We will describe the performance of the instrument and compare the CO and OH emission and upper limit on H2O emission to other Herbig Ae/Be stars. Specifically, L-band observationsof the ro-vibrational OH emission from the disk surrounding HD 250550 is compared to emission properties of the sources studied by Brittain et al. (2016). The OH 2Π3/2 P4.5 (1+,1-) doublet and the P5.5 (1+) line are spectrally resolved and have the same spectral profile as the CO ro-vibrational lines indicating that they arise from the same emitting region of the disk. The relative fluxes of the ro-vibrational lines from CO indicate that the rotational temperature of the gas is 1060 ± 115 K. The relative fluxes of the ro-vibrational lines from OH are consistent with this temperature.

Chemical Abundance Analysis of Moving Group W11450 (Latham 1)

NASA Astrophysics Data System (ADS)

O'Connell, Julia E.; Martens, Kylee; Frinchaboy, Peter M.

2016-12-01

We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis exists in literature. Abundances for eight elements were derived via equivalent width analyses of high-resolution (R ˜ 60,000), high-signal-to-noise ratio (< {{S}}/{{N}}> ˜ 100) spectra obtained with the Otto Struve 2.1 m telescope and the Sandiford Echelle Spectrograph at McDonald Observatory. The large star-to-star scatter in metallicity, -0.55 ≤ [Fe/H] ≤slant 0.06 dex (σ = 0.25), implies these stars were not produced from the same chemically homogeneous molecular cloud, and are therefore not part of a remnant or open cluster as previously proposed. Prior to this analysis, it was suggested that two stars in the group, W11449 and W11450, are possible wide binaries. The candidate wide binary pair show similar chemical abundance patterns with not only iron but with other elements analyzed in this study, suggesting the proposed connection between these two stars may be real.

The Properties of Single Interstellar Clouds: Cycle 1, SIDE-2 Observations

NASA Astrophysics Data System (ADS)

Hobbs, Lewis

1990-12-01

WE PROPOSE TO USE THE ECHELLE GRATING OF THE HIGH RESOLUTION SPECTROGRAPH OVER A TWO-YEAR PERIOD TO OBSERVE THE PROFILES OF INTERSTELLAR ABSORPTION LINES. THE COLUMN DENSITES OF 18 NEUTRAL OR IONIZED FORMS OF THE ELEMENTS C,N,O,Mg,Si,P,S,Fe, AND Zn WILL BE MEASURED IN THE APPROXIMATELY 100 INDIVIDUAL INTERSTELLAR CLOUDS ALONG THE LIGHT PATHS TO 18 BRIGHT, BROAD-LINED STARS OF EARLY SPECTRAL TYPE WITHIN 1 KPC OF THE SUN. THE PRIMARY PURPOSE OF THE OBSERVATIONS IS TO DETERMINE MORE ACCURATELY THAN WAS HITHERTO POSSIBLE THE FUNDAMENTAL PHYSICAL PROPERTIES OF THE RESOLVED CLOUDS, INCLUDING LINEAR SIZE, TEMPERATURE, TOTAL DENSITY, FRACTIONAL IONIZATION AND THE RELATIVE ABUNDANCES OF THE 9 SELECTED ELEMENTS. THE REST OF THIS OBSERVING PROGRAM IS CONTAINED IN APPROVED PROPOSAL ID = 2251; THE PROGRAM EUNUMERATED HERE CONSISTS OF THAT PART OF OUR ORIGINAL PROGRAM WHICH CAN BE CARRIED OUT USING ONLY SIDE 2 OF THE GHRS. THIS PROGRAM THEREFORE CONSISTS OF ECH-B OBSERVATIONS OF EACH OF 4 STARS AT 7 WAVELENGTHS. PROGRAM 2251 SHOULD BE CONSULTED FOR ADDITIONAL DETAILS.

The Properties of Single Interstellar Clouds: Hopr Repeat Cycle 1, SIDE-2 Observations

NASA Astrophysics Data System (ADS)

Hobbs, Lewis

1990-12-01

WE PROPOSE TO USE THE ECHELLE GRATING OF THE HIGH RESOLUTION SPECTROGRAPH OVER A TWO-YEAR PERIOD TO OBSERVE THE PROFILES OF INTERSTELLAR ABSORPTION LINES. THE COLUMN DENSITES OF 18 NEUTRAL OR IONIZED FORMS OF THE ELEMENTS C,N,O,Mg,Si,P,S,Fe, AND Zn WILL BE MEASURED IN THE APPROXIMATELY 100 INDIVIDUAL INTERSTELLAR CLOUDS ALONG THE LIGHT PATHS TO 18 BRIGHT, BROAD-LINED STARS OF EARLY SPECTRAL TYPE WITHIN 1 KPC OF THE SUN. THE PRIMARY PURPOSE OF THE OBSERVATIONS IS TO DETERMINE MORE ACCURATELY THAN WAS HITHERTO POSSIBLE THE FUNDAMENTAL PHYSICAL PROPERTIES OF THE RESOLVED CLOUDS, INCLUDING LINEAR SIZE, TEMPERATURE, TOTAL DENSITY, FRACTIONAL IONIZATION AND THE RELATIVE ABUNDANCES OF THE 9 SELECTED ELEMENTS. THE REST OF THIS OBSERVING PROGRAM IS CONTAINED IN APPROVED PROPOSAL ID = 2251; THE PROGRAM EUNUMERATED HERE CONSISTS OF THAT PART OF OUR ORIGINAL PROGRAM WHICH CAN BE CARRIED OUT USING ONLY SIDE 2 OF THE GHRS. THIS PROGRAM THEREFORE CONSISTS OF ECH-B OBSERVATIONS OF EACH OF 4 STARS AT 7 WAVELENGTHS. PROGRAM 2251 SHOULD BE CONSULTED FOR ADDITIONAL DETAILS.

VizieR Online Data Catalog: UBV light curves of DQ Tau and UZ Tau E (Ardila+, 2015)

NASA Astrophysics Data System (ADS)

Ardila, D. R.; Jonhs-Krull, C.; Herczeg, G. J.; Mathieu, R. D.; Quijano-Vodniza, A.

2016-01-01

DQ Tau was observed with HST/COS four times per binary orbit, during three consecutive binary orbits, at phases ~0, ~0.2, ~0.5, and ~0.7 (in 2011 Feb, Mar). The original experimental design called for observations of UZ Tau E with the same cadence. However, the NUV observations at phase ~0.7 in the second orbit and both the FUV and NUV observations at phase ~0 in the third orbit failed. They were replaced by observations at phases ~0 and ~0.5 in a fourth binary orbit (in 2011 Feb, Mar, Apr). We obtained contemporaneous ground-based UBV photometry with the 14" telescope from the University of Narino Observatory, optical spectroscopy with the Sandiford Echelle Spectrometer on the 2.1m Otto Struve Telescope at McDonald Observatory, near-infrared spectroscopy with the CSHELL spectrograph on the NASA Infrared Telescope Facility, and near-infrared spectroscopy with GNIRS instrument on Gemini North. In this paper we focus on the U-band photometry only. UBV observations were obtained before and during the HST campaign. See table 3. (1 data file).

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: part 2, photon noise theory

NASA Astrophysics Data System (ADS)

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward; Sirk, Martin; Muirhead, Philip S.; Muterspaugh, Matthew W.; Lloyd, James P.

2016-10-01

High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoretical photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (˜1×) EDI has ˜1.4× smaller noise than conventional, and at >10× boost, EDI has ˜1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. For three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).

Experimental and Observational Studies of Molecular Hydrogen in Interstellar and Circumstellar Environments

NASA Astrophysics Data System (ADS)

Hoadley, Keri

2017-08-01

Understanding the evolution of gas over the lifetime of protoplanetary disks provides us with important clues about how planet formation mechanisms drive the diversity of exoplanetary systems observed to date. In the first part of my thesis, I discuss how I use fluorescent emission observations of molecular hydrogen (H2) in the far-ultraviolet (far-UV) with the Hubble Space Telescope to study the warm molecular regions (a < 10 AU) of planet-forming disks. I have created analytic disk models that produce synthetic H2 line profiles and statistically compare each disk realization with the data. I how the modeled radial distributions of H 2 help provide important constraints on the radiation properties of gas left in the inner disk of protoplanetary disks as they evolve. Additionally, I analyzed the absorption component of these fluorescence features, embedded within the hydrogen Lyman-alpha emission line produced by the accretion of material onto the host protostar. I present column density and temperature estimates for the H2 populations in each disk sightline, and discuss the behavior and possible spatial origins of these hot molecules. As part of my thesis, I address some observational requirements needed to gain further insights into the behavior of the warm, gaseous protoplanetary disk, focusing specifically on a spectrograph concept for the next-generation LUVOIR Surveyor. I discuss a testbed instrument, the Colorado High-resolution Echelle Stellar Spectrograph (CHESS), built as a demonstration of one component of the LUVOIR spectrograph and new technological improvements to UV optical components for the next generation of near- to far-UV astrophysical observatories. CHESS is a far-UV sounding rocket experiment designed to probe the warm and cool atoms and molecules near sites of recent star formation in the local interstellar medium. I present the science goals, design, research and development components, and calibration of the CHESS instrument. I provide results on observations taken during both launches of CHESS, with detailed analysis of the epsilon Per sightline, as inferred from the flight data. I conclude by providing future works and simple estimates of the performance of an instrument like CHESS on LUVOIR to study planet-forming environments.

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 2, photon noise theory

DOE PAGES

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward; ...

2016-10-01

High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoreticalmore » photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (~1×) EDI has ~1.4× smaller noise than conventional, and at >10× boost, EDI has ~1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. As a result, for three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).« less

High-resolution broadband spectroscopy using externally dispersed interferometry at the Hale telescope: Part 2, photon noise theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erskine, David J.; Edelstein, Jerry; Wishnow, Edward

High-resolution broadband spectroscopy at near-infrared (NIR) wavelengths (950 to 2450 nm) has been performed using externally dispersed interferometry (EDI) at the Hale telescope at Mt. Palomar, with the TEDI interferometer mounted within the central hole of the 200-in. primary mirror in series with the comounted TripleSpec NIR echelle spectrograph. These are the first multidelay EDI demonstrations on starlight. We demonstrated very high (10×) resolution boost and dramatic (20× or more) robustness to point spread function wavelength drifts in the native spectrograph. Data analysis, results, and instrument noise are described in a companion paper (part 1). This part 2 describes theoreticalmore » photon limited and readout noise limited behaviors, using simulated spectra and instrument model with noise added at the detector. We show that a single interferometer delay can be used to reduce the high frequency noise at the original resolution (1× boost case), and that except for delays much smaller than the native response peak half width, the fringing and nonfringing noises act uncorrelated and add in quadrature. This is due to the frequency shifting of the noise due to the heterodyning effect. We find a sum rule for the noise variance for multiple delays. The multiple delay EDI using a Gaussian distribution of exposure times has noise-to-signal ratio for photon-limited noise similar to a classical spectrograph with reduced slitwidth and reduced flux, proportional to the square root of resolution boost achieved, but without the focal spot limitation and pixel spacing Nyquist limitations. At low boost (~1×) EDI has ~1.4× smaller noise than conventional, and at >10× boost, EDI has ~1.4× larger noise than conventional. Readout noise is minimized by the use of three or four steps instead of 10 of TEDI. Net noise grows as step phases change from symmetrical arrangement with wavenumber across the band. As a result, for three (or four) steps, we calculate a multiplicative bandwidth of 1.8:1 (2.3:1), sufficient to handle the visible band (400 to 700 nm, 1.8:1) and most of TripleSpec (2.6:1).« less

The Magellan Project

NASA Astrophysics Data System (ADS)

Shectman, Stephen A.

1995-05-01

The Magellan project is a collaboration between the Carnegie Institution of Washington and the University of Arizona to build and operate a 6.5-meter telescope at the Las Campanas Observatory in Chile. Negotiations which are presently underway with additional partners are likely to result in the construction of a second identical telescope as part of the same facility. The concrete work for the first telescope has been completed. The steel structure for the fixed part of the dome and for the aluminizing building has been shipped to the site. The structure for the rotating part of the dome should arrive at the site by the end of 1995. The telescope mount is being constructed by L&F Industries of Huntington Park, CA. Most of the structure has been fabricated and machining of the parts is underway. Shop assembly of the mount is scheduled to be completed by the end of 1995, and the mount should arrive at the site by mid-1996. The borosilicate honeycomb mirror blank for the first telescope was cast at the Steward Observatory Mirror Lab in February, 1994. The refractory material is presently being cleaned out of the honeycomb cores, and figuring should begin in 1996. The schedule calls for the mirror to be installed in the telescope by mid-1997. The optical design of the telescope features an f/11 Gregorian secondary for which the field curvature is matched to the collimator optics of a wide-field imaging spectrograph. A two-element field corrector incorporates an atmospheric dispersion compensator with no additional glass-air surfaces. The matching field curvatures permit the collimator to cover a very wide field (30 arc-min) with high image quality (0.1 arc-sec rms). Cameras and detectors which make use of such a wide field are challenging but at least conceivable from a technical point of view. A compact echelle spectrograph has also been designed to work in the resolution range 30-50,000. Spectral coverage will be complete between 3500A and 8500A. The spectrograph has been designed for high throughput and the CCD readouts will be optimized in a novel way to minimize the effect of amplifier noise for observations of faint objects.

CARMENES: Commissioning and first scientific results at the telescope. A precursor for HIRES@E-ELT

NASA Astrophysics Data System (ADS)

Amado, P. J.; The Carmenes Consortium

2017-03-01

CARMENES is the next generation instrument built for the CAHA 3.5m telescope by a large international consortium of 11 institutes in Spain and Germany. It consists of two separate highly-stabilized, high-resolution echelle spectrographs covering both the visible, from 550 to 950 nm, and the near-IR, from 950 to 1700 nm, wavelength ranges with spectral resolution of R=82,000. They are fed by fibres from the Cassegrain focus of the telescope and were designed and built to achieve high-accuracy radial velocities of nearby M-dwarf stars. This contribution overviews the main and unique design characteristics of CARMENES. The instrument MAIV phase was achieved in the last two years (2014-2015) and started commissioning in November 2015. The commissioning phases, both technical and scientific, took six full weeks in the last two months of 2015. They have shown that the instrument is well within requirements and performing to be able to achieve its objective, not proven before in the near-infrared, of providing radial velocities precisions of 5 ms^{-1}, with a goal of 1 ms^{-1}. The Guaranteed Time Observations (GTO) program has started in January 1st, 2016. CARMENES is, therefore, currently conducting a radial-velocity survey of 300 M dwarfs with a precision sufficient for detecting Earth-like planets in their habitable zones. It is also being offered in open time by the CAHA. Its modular design is the idea in which HIRES, the next very high-resolution, high-fidelity spectrograph with wide wavelength coverage at the E-ELT, is based on. This E-ELT instrument might consist of four different high-resolution spectrographs covering the blue, the visible, the near-infrared (Y, J and H bands) and the K band. A proposal to the ESO call for Phase-A studies for a HIRES at the E-ELT was submitted by the HIRES consortium last December. This proposal was accepted by ESO and the Phase-A kick-off meeting between ESO and the consortium took place in March 22, 2016.

Astigmatism-corrected echelle spectrometer using an off-the-shelf cylindrical lens.

PubMed

Fu, Xiao; Duan, Fajie; Jiang, Jiajia; Huang, Tingting; Ma, Ling; Lv, Changrong

2017-10-01

As a special kind of spectrometer with the Czerny-Turner structure, the echelle spectrometer features two-dimensional dispersion, which leads to a complex astigmatic condition. In this work, we propose an optical design of astigmatism-corrected echelle spectrometer using an off-the-shelf cylindrical lens. The mathematical model considering astigmatism introduced by the off-axis mirrors, the echelle grating, and the prism is established. Our solution features simplified calculation and low-cost construction, which is capable of overall compensation of the astigmatism in a wide spectral range (200-600 nm). An optical simulation utilizing ZEMAX software, astigmatism assessment based on Zernike polynomials, and an instrument experiment is implemented to validate the effect of astigmatism correction. The results demonstrated that astigmatism of the echelle spectrometer was corrected to a large extent, and high spectral resolution better than 0.1 nm was achieved.

VizieR Online Data Catalog: Radial velocity curve of 51 Peg (Birkby+, 2017)

NASA Astrophysics Data System (ADS)

Birkby, J. L.; de Kok, R. J.; Brogi, M.; Schwarz, H.; Snellen, I. A. G.

2017-07-01

We observed the bright star 51 Peg (G2.5V, V=5.46mag, K=3.91mag) for 3.7hr during the night beginning 2010 October 21, using the CRyogenic InfraRed Echelle Spectrograph (CRIRES) mounted at Nasmyth A at the VLT (8.2 m UT1/Antu), Cerro Paranal, Chile. The observations were collected as part of the ESO large program 186.C-0289. The instrument setup consisted of a 0.2 arcsec slit centred on 3236nm (order 17), in combination with the Multi-Application Curvature Adaptive Optic system (MACAO). The CRIRES infrared detector is comprised of four Aladdin III InSb-arrays, each with 1024*512 pixels, and separated by a gap of 280 pixels. The resulting wavelength coverage of the observations was 3.1806<λ(μm)<3.2659 with a resolution of R{approx}100000 per resolution element. We observed 51 Peg continuously while its hot Jupiter companion passed through orbital phases 0.55<~{Phi}<~0.58, corresponding to an expected change in the planet's radial velocity of ΔRVP=-23km/s (15 pixels on the CRIRES detectors). In total, we obtained 42 spectra, with the first 20 spectra each consisting of two sets of 5*20s exposures, and the remainder each consisting of two sets of 5*30s exposures. The increase in the exposure time was aimed at maintaining a constant signal-to-noise ratio (S/N) in the continuum of the observed stellar spectra after a sudden and significant deterioration of the seeing (increasing from 0.75 to 1.4 arcsec between one set of frames, see Section 2.3). To enable accurate sky-background subtraction, the telescope was nodded along the slit by 10 arcsec between each set of exposures in a classic ABBA sequence, with each of the final 42 extracted spectra consisting of an AB or BA pair. A standard set of CRIRES calibration frames was taken the following morning. To ensure we had its most up-to-date orbital solution, we compiled an extensive repository of literature and archival radial velocity measurements of the star 51 Peg from multiple observatories. These data are given in Table 1 and span observing dates from 1994 September 15 to 2014 July 9, resulting in 639 radial velocity measurements over 20 years. The table includes the discovery measurements from the ELODIE spectrograph at Observatoire Haute Provence and subsequent additional monitoring. We took these radial velocity measurements from the Naef et al. 2004 (Cat. J/A+A/414/351) compilation. We also included the legacy data set from Lick Observatory observed with the Hamilton spectrograph, taking measurements from the self-consistent reprocessing of all the Lick spectra presented by Fischer et al. 2014 (Cat. J/ApJS/210/5). Finally, we included more recent additional monitoring from the High Resolution Echelle Spectrometer (HIRES) at the Keck Observatory, and extracted RVs from observations with the High Accuracy Radial velocity Planet Searcher (HARPS) at the ESO-3.6m telescope in 2013 (ESO program ID 091.C-0271, PI: Santos). The reduced HARPS spectra were obtained from the ESO Science Archive (http://archive.eso.org/wdb/wdb/adp/phase3_spectral/query). (1 data file).

Optical design of the NASA-NSF extreme precision Doppler spectrograph concept "WISDOM"

NASA Astrophysics Data System (ADS)

Barnes, Stuart I.; Fżrész, Gábor; Simcoe, Robert A.; Shectman, Stephen A.; Woods, Deborah F.

2016-08-01

The WISDOM instrument concept was developed at MIT as part of a NASA-NSF funded study to equip the 3.5m WIYN telescope with an extremely precise radial velocity spectrometer. The spectrograph employs an asymmetric white pupil optical design, where the instrument is split into two nearly identical "Short" (380 to 750 nm) and "Long"" (750 to 1300 nm) wavelength channels. The echelle grating and beam sizes are R3.75/125mm and R6/80mm in the short and long channels respectively. Together with the pupil slicer, and octagonal to rectangular fibre coupling, this permits resolving powers over R = 120k with a 1.2" diameter fibre on the sky. A factor of two reduction in the focal length between the main collimator OAP and the transfer collimator ensures a very compact instrument, with a small white pupil footprint, thereby enabling small cross-dispersing and camera elements. A dichroic is used near the white pupil to split each of the long and short channels into two, so that the final spectrograph has 4 channels; namely "Blue," "Green," "Red" and "NIR." Each of these channels has an anamorphic VPH grism for cross-dispersion, and a fully dioptric all-spherical camera objective. The spectral footprints cover 4k×4k and 6k×6k CCDs with 15 µm pixels in the short "Blue" and "Green" wavelength channels, respectively. A 4k×4k CCD with 15 μm pixels is used in the long "Red" channel, with a HgCdTe 1.7 μm cutoff 4k×4k detector with 10um pixels is to be used in the long "NIR" channel. The white pupil relay includes a Mangin mirror very close to the intermediate focus to correct the white pupil relay Petzval curvature before it is swept into a cylinder by the cross-dispersers. This design decision allows each of the dioptric cameras to be fully optimised and tested independently of the rest of the spectrograph. The baseline design for the cameras also ensures that the highest possible (diffraction limited) image quality is achieved across all wavelengths, while also ensuring insensitivity of spot centroid locations to variations in the pupil illumination. This insensitivity is proven to remain even in the presence of reasonable manufacturing and alignment tolerances. Fully ray-traced simulations of the spectral formats are used to demonstrate the optical performance, as well as to provide pre-first-light data that can be used to optimise the data reduction pipeline.

Capabilities, performance, and status of the SOFIA science instrument suite

NASA Astrophysics Data System (ADS)

Miles, John W.; Helton, L. Andrew; Sankrit, Ravi; Andersson, B. G.; Becklin, E. E.; De Buizer, James M.; Dowell, C. D.; Dunham, Edward W.; Güsten, Rolf; Harper, Doyal A.; Herter, Terry L.; Keller, Luke D.; Klein, Randolf; Krabbe, Alfred; Marcum, Pamela M.; McLean, Ian S.; Reach, William T.; Richter, Matthew J.; Roellig, Thomas L.; Sandell, Göran; Savage, Maureen L.; Smith, Erin C.; Temi, Pasquale; Vacca, William D.; Vaillancourt, John E.; Van Cleve, Jeffery E.; Young, Erick T.; Zell, Peter T.

2013-09-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) is an airborne observatory, carrying a 2.5 m telescope onboard a heavily modified Boeing 747SP aircraft. SOFIA is optimized for operation at infrared wavelengths, much of which is obscured for ground-based observatories by atmospheric water vapor. The SOFIA science instrument complement consists of seven instruments: FORCAST (Faint Object InfraRed CAmera for the SOFIA Telescope), GREAT (German Receiver for Astronomy at Terahertz Frequencies), HIPO (High-speed Imaging Photometer for Occultations), FLITECAM (First Light Infrared Test Experiment CAMera), FIFI-LS (Far-Infrared Field-Imaging Line Spectrometer), EXES (Echelon-Cross-Echelle Spectrograph), and HAWC (High-resolution Airborne Wideband Camera). FORCAST is a 5-40 μm imager with grism spectroscopy, developed at Cornell University. GREAT is a heterodyne spectrometer providing high-resolution spectroscopy in several bands from 60-240 μm, developed at the Max Planck Institute for Radio Astronomy. HIPO is a 0.3-1.1 μm imager, developed at Lowell Observatory. FLITECAM is a 1-5 μm wide-field imager with grism spectroscopy, developed at UCLA. FIFI-LS is a 42-210 μm integral field imaging grating spectrometer, developed at the University of Stuttgart. EXES is a 5-28 μm high-resolution spectrograph, developed at UC Davis and NASA ARC. HAWC is a 50-240 μm imager, developed at the University of Chicago, and undergoing an upgrade at JPL to add polarimetry capability and substantially larger GSFC detectors. We describe the capabilities, performance, and status of each instrument, highlighting science results obtained using FORCAST, GREAT, and HIPO during SOFIA Early Science observations conducted in 2011.

High precision radial velocities with GIANO spectra

NASA Astrophysics Data System (ADS)

Carleo, I.; Sanna, N.; Gratton, R.; Benatti, S.; Bonavita, M.; Oliva, E.; Origlia, L.; Desidera, S.; Claudi, R.; Sissa, E.

2016-06-01

Radial velocities (RV) measured from near-infrared (NIR) spectra are a potentially excellent tool to search for extrasolar planets around cool or active stars. High resolution infrared (IR) spectrographs now available are reaching the high precision of visible instruments, with a constant improvement over time. GIANO is an infrared echelle spectrograph at the Telescopio Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution spectra for accurate RV measurements of exoplanets and for chemical and dynamical studies of stellar or extragalactic objects. No other high spectral resolution IR instrument has GIANO's capability to cover the entire NIR wavelength range (0.95-2.45 μm) in a single exposure. In this paper we describe the ensemble of procedures that we have developed to measure high precision RVs on GIANO spectra acquired during the Science Verification (SV) run, using the telluric lines as wavelength reference. We used the Cross Correlation Function (CCF) method to determine the velocity for both the star and the telluric lines. For this purpose, we constructed two suitable digital masks that include about 2000 stellar lines, and a similar number of telluric lines. The method is applied to various targets with different spectral type, from K2V to M8 stars. We reached different precisions mainly depending on the H-magnitudes: for H ˜ 5 we obtain an rms scatter of ˜ 10 m s-1, while for H ˜ 9 the standard deviation increases to ˜ 50 ÷ 80 m s-1. The corresponding theoretical error expectations are ˜ 4 m s-1 and 30 m s-1, respectively. Finally we provide the RVs measured with our procedure for the targets observed during GIANO Science Verification.

ESPRESSO: the ultimate rocky exoplanets hunter for the VLT

NASA Astrophysics Data System (ADS)

Mégevand, Denis; Zerbi, Filippo M.; Cabral, Alexandre; Di Marcantonio, Paolo; Amate, Manuel; Pepe, Francesco; Cristiani, Stefano; Rebolo, Rafael; Santos, Nuno C.; Dekker, Hans; Abreu, Manuel; Affolter, Michael; Avila, Gerardo; Baldini, Veronica; Bristow, Paul; Broeg, Christopher; Carvas, Pedro; Cirami, Roberto; Coelho, João.; Comari, Maurizio; Conconi, Paolo; Coretti, Igor; Cupani, Guido; D'Odorico, Valentina; De Caprio, Vincenzo; Delabre, Bernard; Figueira, Pedro; Fleury, Michel; Fragoso, Ana; Genolet, Ludovic; Gomes, Ricardo; Gonzalez Hernandez, Jonay; Hughes, Ian; Iwert, Olaf; Kerber, Florian; Landoni, Marco; Lima, Jorge; Lizon, Jean-Louis; Lovis, Christophe; Maire, Charles; Mannetta, Marco; Martins, Carlos; Moitinho, André; Molaro, Paolo; Monteiro, Manuel; Rasilla, José Luis; Riva, Marco; Santana Tschudi, Samuel; Santin, Paolo; Sosnowska, Danuta; Sousa, Sergio; Spanò, Paolo; Tenegi, Fabio; Toso, Giorgio; Vanzella, Eros; Viel, Matteo; Zapatero Osorio, Maria Rosa

2012-09-01

ESPRESSO, the VLT rocky exoplanets hunter, will combine the efficiency of modern echelle spectrograph with extreme radial-velocity precision. It will be installed at Paranal on ESO's VLT in order to achieve a gain of two magnitudes with respect to its predecessor HARPS, and the instrumental radial-velocity precision will be improved to reach 10 cm/s level. We have constituted a Consortium of astronomical research institutes to fund, design and build ESPRESSO on behalf of and in collaboration with ESO, the European Southern Observatory. The project has passed the preliminary design review in November 2011. The spectrograph will be installed at the so-called "Combined Coudé Laboratory" of the VLT, it will be linked to the four 8.2 meters Unit Telescopes (UT) through four optical "Coudé trains" and will be operated either with a single telescope or with up to four UTs. In exchange of the major financial and human effort the building Consortium will be awarded with guaranteed observing time (GTO), which will be invested in a common scientific program. Thanks to its characteristics and the ability of combining incoherently the light of 4 large telescopes, ESPRESSO will offer new possibilities in many fields of astronomy. Our main scientific objectives are, however, the search and characterization of rocky exoplanets in the habitable zone of quiet, near-by G to M-dwarfs, and the analysis of the variability of fundamental physical constants. In this paper, we present the ambitious scientific objectives, the capabilities of ESPRESSO, the technical solutions for the system and its subsystems, enlightening the main differences between ESPRESSO and its predecessors. The project aspects of this facility are also described, from the consortium and partnership structure to the planning phases and milestones.

VizieR Online Data Catalog: Radial velocities of 1 Gem (Lane+, 2014)

NASA Astrophysics Data System (ADS)

Lane, B. F.; Muterspaugh, M. W.; Griffin, R. F.; Scarfe, C. D.; Fekel, F. C.; Williamson, M. H.; Eaton, J. A.; Shao, M.; Colavita, M. M.; Konacki, M.

2016-05-01

Extensive radial-velocity measurements of the 1 Gem system have been obtained in four separate campaigns spanning 40yr, including data from eight different instruments. Between 1969 and 2009 R.F.G. acquired a total of 128 observations of 1 Gem using the original radial-velocity spectrometer at Cambridge; a second-generation, computerized instrument at Palomar; the CORAVEL spectrometer at Haute Provence Observatory (OHP), and most recently, the Cambridge CORAVEL. The "Cambridge CORAVEL" operates at the Coude focus of the 36inch reflector on the home site of the Cambridge Observatories, Madingley Road, Cambridge, England. The Cambridge and Palomar data are referred to as data set A, while the OHP data are labeled set B. The data for components A and Ba are provided in Table1. A series of observations of 1 Gem has been obtained by C.D.S. with the Dominion Astrophysical Observatory (DAO) radial-velocity spectrometer. Observations were begun early in 1980 and continued until the end of 2003. The DAO velocities of components A and Ba are listed in Table2. The total number of acceptable velocities from DAO radial-velocity scanner observations is 123 of the primary star and 107 of the brighter component of the close pair. The third component was not detectable in the DAO traces. We identify the DAO observations as data set C. >From 1983 through 2009 F.C.F. obtained observations at the Kitt Peak National Observatory (KPNO) with the 0.9m coude feed telescope, coude spectrograph, and several different CCD detectors. All of the spectrograms were acquired with a Texas Instruments (TI) CCD except for five that were obtained in 1983 with an RCA CCD and a single observation in 2008 September with a Tektronix CCD. All those observations were centered near 6430Å and had typical signal-to-noise ratios of about 250. The numerous TI CCD spectra have a wavelength range of just 84Å and a resolution of 0.21Å. The 86 velocities of component A and 80 of component Ba are listed in Table3. They are identified as data set D. >From 2003 through 2009 J.A.E. acquired 522 spectrograms with the Tennessee State University 2m Automatic Spectroscopic Telescope (AST) situated at Fairborn Observatory near Washington Camp in the Patagonia Mountains of southeastern Arizona, fiber-fed echelle spectrograph, and a 2048*4096 SITe ST-002A CCD. The echelle spectrograms have 21 orders, covering the wavelength range 4920-7100Å with an average resolution of 0.17Å. The typical signal-to-noise ratio is ~50. The AST spectra are referred to as data set E (see Table4). (4 data files).

Abundances of neutron-capture elements in stars of the Galactic disk substructures

NASA Astrophysics Data System (ADS)

Mishenina, T. V.; Pignatari, M.; Korotin, S. A.; Soubiran, C.; Charbonnel, C.; Thielemann, F.-K.; Gorbaneva, T. I.; Basak, N. Yu.

2013-04-01

Aims: The aim of this work is to present and discuss the observations of the iron peak (Fe, Ni) and neutron-capture element (Y, Zr, Ba, La, Ce, Nd, Sm, and Eu) abundances for 276 FGK dwarfs, located in the Galactic disk with metallicity -1 < [Fe/H] < +0.3. Methods: Atmospheric parameters and chemical composition of the studied stars were determined from an high resolution, high signal-to-noise echelle spectra obtained with the echelle spectrograph ELODIE at the Observatoire de Haute-Provence (France). Effective temperatures were estimated by the line depth ratio method and from the Hα line-wing fitting. Surface gravities (log g) were determined by parallaxes and the ionization balance of iron. Abundance determinations were carried out using the LTE approach, taking the hyperfine structure for Eu into account, and the abundance of Ba was computed under the NLTE approximation. Results: We are able to assign most of the stars in our sample to the substructures of the Galaxy thick disk, thin disk, or Hercules stream according to their kinematics. The classification of 27 stars is uncertain. For most of the stars in the sample, the abundances of neutron-capture elements have not been measured earlier. For all of them, we provide the chemical composition and discuss the contribution from different nucleosynthesis processes. Conclusions: The [Ni/Fe] ratio shows a flat value close to the solar one for the whole metallicity range, with a small scatter, pointing to a nearly solar Ni/Fe ratio for the ejecta of both core-collapse SN and SNIa. The increase in the [Ni/Fe] for metallicity higher than solar is confirmed, and it is due to the metallicity dependence of 56Ni ejecta from SNIa. Under large uncertainty in the age determination of observed stars, we verified that there is a large dispersion in the AMR in the thin disk, and no clear trend as in the thick disk. That may be one of the main reasons for the dispersion, observed for the s-process elements in the thin disk (e.g., Ba and La), whereas much narrower dispersion can be seen for r-process elements (e.g., Eu). Within the current uncertainties, we do not see a clear decreasing trend of [Ba/Fe] or [La/Fe] with metallicity in the thin disk, except maybe for super-solar metallicities. We cannot confirm an increase in the mentioned ratios with decreasing stellar age. Based on spectra collected with the ELODIE spectrograph at the 1.93-m telescope of the Observatoire de Haute Provence (France).Tables 4 and 5 are only available at the CDS via anonymous ftp to ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/552/A128

VizieR Online Data Catalog: Interferometry and spectroscopy of sigma Orionis (Schaefer+, 2016)

NASA Astrophysics Data System (ADS)

Schaefer, G. H.; Hummel, C. A.; Gies, D. R.; Zavala, R. T.; Monnier, J. D.; Walter, F. M.; Turner, N. H.; Baron, F.; Ten Brummelaar, T.; Che, X.; Farrington, C. D.; Kraus, S.; Sturmann, J.; Sturmann, L.

2017-03-01

Interferometric data on the σ Orionis triple system were collected between 2010 and 2013 at the CHARA Array located on Mount Wilson, California. The array has six 1m telescopes arranged in a Y configuration with baselines ranging from 34 to 331m. here are two telescopes in each arm, labeled as E (East), W (West), and S (South). We used the Michigan Infrared Combiner (MIRC) to combine the light from three to six telescopes simultaneously. All data were collected after the photometric channels were installed in MIRC; the photometric channels measure the amount of light received from each telescope during the observations to improve the calibration. We used the low spectral resolution prism (R~42) to disperse the fringes across eight spectral channels in the H band (λ=1.5-1.8μm). Navy Prototype Optical Interferometer (NPOI) observations of σ Orionis were collected over a period from 2000 to 2013. Initially, the observations were obtained with the 3-beam combiner, and then, starting in 2002, with the 6-beam hybrid combiner. The NPOI beam combiners disperse the light and record the visibility spectra from 550 to 850 nm in 16 spectral channels. In total, some 59 nights of observations were executed, of which 26 nights were of good quality. The calibrators were selected from a list of single stars maintained at NPOI with diameters estimated from V and (V-K) using the surface brightness relation published by Mozurkewich et al. 2003AJ....126.2502M and van Belle et al. 2009MNRAS.394.1925V. The information for all of the calibrators is given in Table5. We obtained new spectroscopic radial velocity measurements of σ Orionis Aa,Ab using the 1.5m telescope at Cerro Tololo Inter-American Observatory (CTIO). We obtained 40 observations on 29 nights using the Fiber Echelle (FE) Spectrograph (http://www.ctio.noao.edu/~atokovin/echelle/FECH-overview.html) (R=25000, λ=4800-7000Å) between UT 2008 September 23 and 2009 February 21. Additional observations were obtained using the Chiron fiber-fed echelle spectrometer equipped with an image slicer (R=78000, λ=4550-8800Å) on 10 nights between UT 2012 November 4 and 2013 February 2 and 11 nights between UT 2016 January 21 and March 27. The Chiron observations were concentrated near the periastron passage of the close pair. The median radial velocities of σ Ori Aa and Ab, measured from the selected spectral lines, are presented in Table8. (5 data files).

Ultraviolet micro-Raman spectrograph for the detection of small numbers of bacterial cells

NASA Astrophysics Data System (ADS)

Chadha, S.; Nelson, W. H.; Sperry, J. F.

1993-11-01

The construction of a practical UV micro-Raman spectrograph capable of selective excitation of bacterial cells and other microscopic samples has been described. A reflective objective is used to focus cw laser light on a sample and at the same time collect the scattered light at 180°. With the aid of a quartz lens the image produced is focused on the slits of a spectrograph equipped with a single 2400 grooves/mm grating optimized for 250 nm. Spectra were detected by means of a blue-intensified diode array detector. Resonance Raman spectra of Bacillus subtilis and Flavobacterium capsulatum excited by the 257.2 nm output of a cw laser were recorded in the 900-1800 cm-1 region. Bacterial cells were immobilized on a quartz plate by means of polylysine and were counted visually. Cooling was required to retard sample degradation. Sample sizes ranged from 1 to 50 cells with excitation times varying from 15 to 180 s. Excellent spectra have been obtained from 20 cells in 15 s using a spectrograph having only 3% throughput.

Mini-Spec: A Compact, Fiber-Coupled, VPH Grating Spectrograph for Small Observatories

NASA Astrophysics Data System (ADS)

Nations, H. L.; Haynes, P.; Brewer, P.

2003-05-01

We report on the development and testing of what we believe to be the first VPH grating based spectrograph developed primarily for use at telescopes of modest aperture. To date, the most common instrument suite for such observatories is typically that of a CCD camera with attached filter wheel. While there is no doubt that a wide range of interesting and good science has been done with such instrumentation, the addition of a robust and easy to operate spectrograph would greatly increase the utility of such installations. While some commercial spectrographs exist for use on small telescopes, the authors have found them to be, with few exceptions, either inefficient, difficult for inexperienced students or amateurs to use, or not remotely operable. Correcting these deficiencies is thus the primary motivation for Mini-Spec. The design of Mini-Spec has been influenced by previous work the authors have done on a full-sized fiber-coupled spectrograph (Nations and Pierce, 2002). Mini-Spec uses some of those original design features, only reduced drastically in size. This size reduction (the spectrograph fits within a 7 inch cube), along with a much more careful choice of some critical components, has resulted in a dramatic reduction in cost. The spectrograph uses a highly efficient 1200 l/mm, 40 mm diameter vph grating on loan from Richard Rallison. Focus, central wavelength selection, and comparison lamps are all controlled via an RS-232 link and a custom Visual Basic GUI. Sample spectra of stellar and non-stellar targets will be presented along with a discussion of research projects admirably suited for this instrument. Funding for equipment has been provided by a NASA EPSCoR grant to PI Ron Canterna. HLN has been partially funded by a Wyoming Space Grant Faculty Fellowship.

New On-Orbit Sensitivity Calibrationfor All STIS Echelle Modes

NASA Astrophysics Data System (ADS)

Aloisi, Alessandra; Bohlin, Ralph; Quijano, Jessica Kim

2007-01-01

On-orbit sensitivities for the 32 medium- and high-resolution STIS echelle secondarymodes were determined for the rst time using observations of the fundamental DAwhite dwarf standard star G191-B2B. Revised on-orbit sensitivities for the 12 mediumandhigh-resolution echelle prime modes based on observations of the same standardstar are also presented. We review the procedures and assumptions used to derive theadopted throughputs and implement them into the pipeline.

Echelle grating multi-order imaging spectrometer utilizing a catadioptric lens

DOEpatents

Chrisp, Michael P; Bowers, Joel M

2014-05-27

A cryogenically cooled imaging spectrometer that includes a spectrometer housing having a first side and a second side opposite the first side. An entrance slit is on the first side of the spectrometer housing and directs light to a cross-disperser grating. An echelle immersions grating and a catadioptric lens are positioned in the housing to receive the light. A cryogenically cooled detector is located in the housing on the second side of the spectrometer housing. Light from the entrance slit is directed to the cross-disperser grating. The light is directed from the cross-disperser grating to the echelle immersions grating. The light is directed from the echelle immersions grating to the cryogenically cooled detector on the second side of the spectrometer housing.

Post-SM4 Sensitivity Calibration of the STIS Echelle Modes

NASA Astrophysics Data System (ADS)

Bostroem, K. Azalee; Aloisi, A.; Bohlin, R.; Hodge, P.; Proffitt, C.

2012-01-01

On-orbit sensitivity curves for all echelle modes were derived for post - servicing mis- sion 4 data using observations of the DA white dwarf G191-B2B. Additionally, new echelle ripple tables and grating dependent bad pixel tables were created for the FUV and NUV MAMA. We review the procedures used to derive the adopted throughputs and implement them in the pipeline as well as the motivation for the modification of the additional reference files and pipeline procedures.

The ESO Diffuse Interstellar Bands Large Exploration Survey: EDIBLES I. Project description, survey sample and quality assessment.

PubMed

Cox, Nick L J; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J; Marshall, Charlotte C M; Smith, Keith T; Evans, Christopher J; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A; Joblin, Christine; van Loon, Jacco Th; Foing, Bernard H; Bhatt, Neil H; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-10-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the [Formula: see text] fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution ( R ~ 70 000 - 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

Pulsation in the presence of a strong magnetic field: the roAp star HD166473

NASA Astrophysics Data System (ADS)

Mathys, G.; Kurtz, D. W.; Elkin, V. G.

2007-09-01

Phase-resolved high-resolution, high signal-to-noise ratio (S/N) observations of the strongly magnetic roAp star HD166473 are analysed. HD166473 was selected as the target of this study because it has one of the strongest magnetic fields of all the roAp stars known with resolved magnetically split lines. Indeed, we show that enhanced pulsation diagnosis can be achieved from consideration of the different pulsation behaviour of the π and σ Zeeman components of the resolved spectral lines. This study is based on a time-series of high spectral resolution observations obtained with the Ultraviolet and Visual Echelle Spectrograph of the Very Large Telescope of the European Southern Observatory. Radial velocity variations due to pulsation are observed in rare earth lines, with amplitudes up to 110ms-1. The variations occur with three frequencies, already detected in photometry, but which can in this work be determined with better precision: 1.833, 1.886 and 1.928mHz. The pulsation amplitudes and phases observed in the rare earth element lines vary with atmospheric height, as is the case in other roAp stars studied in detail. Lines of Fe and of other (mostly non-rare earth) elements do not show any variation to very high precision (1.5ms-1 in the case of Fe). The low amplitudes of the observed variations do not allow the original goal of studying differences between the behaviour of the resolved Zeeman line components to be reached; the S/N achieved in the radial velocity determinations is insufficient to establish definitely the possible existence of such differences. Yet the analysis provides a tantalizing hint at the occurrence of variations of the mean magnetic field modulus with the pulsation frequency, with an amplitude of 21 +/- 5G. Based on observations collected at the European Southern Observatory, Paranal, Chile, as part of programme 067.D-0272. E-mail: gmathys@eso.org

The ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES) . I. Project description, survey sample, and quality assessment

NASA Astrophysics Data System (ADS)

Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-10-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60^+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort tosystematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral-type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R 70 000-100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

Centrosymmetric molecules as possible carriers of diffuse interstellar bands

NASA Astrophysics Data System (ADS)

Kaźmierczak, M.; Schmidt, M. R.; Galazutdinov, G. A.; Musaev, F. A.; Betelesky, Y.; Krełowski, J.

2010-11-01

In this paper, we present new data with interstellar C2 (Phillips bands A 1 Πu-X1 Σ+g), from observations made with the Ultraviolet-Visual Echelle Spectrograph of the European Southern Observatory. We have determined the interstellar column densities and excitation temperatures of C2 for nine Galactic lines. For seven of these, C2 has never been observed before, so in this case the still small sample of interstellar clouds (26 lines of sight), where a detailed analysis of C2 excitation has been made, has increased significantly. This paper is a continuation of previous works where interstellar molecules (C2 and diffuse interstellar bands) have been analysed. Because the sample of interstellar clouds with C2 has increased, we can show that the width and shape of the profiles of some diffuse interstellar bands (6196 and 5797 Å) apparently depend on the gas kinetic and rotational temperatures of C2; the profiles are broader because of the higher values of the gas kinetic and rotational temperatures of C2. There are also diffuse interstellar bands (4964 and 5850 Å) for which this effect does not exist. Based on observations made with ESO telescopes at the Paranal Observatory under programme IDs 266.D-5655(A), 67.C-0281(A), 71.C-0513(C), 67.D-0439(A) and 082.C-0566(A) and at La Silla under programme IDs 078.C-0403(A), 076.C-0164(A) and 073.C-0337(A). Also based on observations made with the 1.8-m telescope in South Korea and the 2-m telescope at the International Centre for Astronomical and Medico-Ecological Research, Terskol, Russia. E-mail: kazmierczak@astri.uni.torun.pl (MK); schmidt@ncac.torun.pl (MRS); runizag@gmail.com (GAG); ybialets@eso.org (YB); jacek@astri.uni.torun.pl (JK)

The ESO Diffuse Interstellar Bands Large Exploration Survey: EDIBLES I. Project description, survey sample and quality assessment

PubMed Central

Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-01-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R ~ 70 000 – 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305–1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided. PMID:29151608

The SpaceInn-SISMA Database: Characterization of a Large Sample of Variable and Active Stars by Means of Harps Spectra

NASA Astrophysics Data System (ADS)

Rainer, M.; Poretti, E.; Mistò, A.; Panzera, M. R.; Molinaro, M.; Cepparo, F.; Roth, M.; Michel, E.; Monteiro, M. J. P. F. G.

2016-12-01

We created a large database of physical parameters and variability indicators by fully reducing and analyzing the large number of spectra taken to complement the asteroseismic observations of the COnvection, ROtation and planetary Transits (CoRoT) satellite. 7103 spectra of 261 stars obtained with the ESO echelle spectrograph HARPS have been stored in the VO-compliant database Spectroscopic Indicators in a SeisMic Archive (SISMA), along with the CoRoT photometric data of the 72 CoRoT asteroseismic targets. The remaining stars belong to the same variable classes of the CoRoT targets and were observed to better characterize the properties of such classes. Several useful variability indicators (mean line profiles, indices of differential rotation, activity and emission lines) together with v\\sin I and radial-velocity measurements have been extracted from the spectra. The atmospheric parameters {T}{eff},{log}g, and [Fe/H] have been computed following a homogeneous procedure. As a result, we fully characterize a sample of new and known variable stars by computing several spectroscopic indicators, also providing some cases of simultaneous photometry and spectroscopy.

The remarkably high excitation planetary nebula GC 6537

PubMed Central

Aller, Lawrence H.; Hung, Siek; Feibelman, Walter A.

1999-01-01

NGC 6537 is an unusually high excitation point symmetric planetary nebula with a rich spectrum. Its kinematical structures are of special interest. We are here primarily concerned with the high resolution spectrum as revealed by the Hamilton echelle Spectrograph at Lick Observatory (resolution ≈ 0.2 Å) and supplemented by UV and near-UV data. These extensive data permit a determination of interstellar extinction, plasma diagnostics, and ionic concentrations. The photoionization models that have been used successfully for many planetary nebulae are not entirely satisfactory here. The plasma electron temperature of a photoionization model cannot much exceed 20,000 K, but plasma diagnostics show that regions emitting radiation of highly ionized atoms such as [Neiv] and [Nev] are much hotter, showing that shock excitation must be important, as suggested by the remarkable kinematics of this object. Hence, instead of employing a strict photoionization model, we are guided by the nebular diagnostics, which reveal how electron temperature varies with ionization potential and accommodates density effects. The predictions of the photoionization model may be useful in estimating ionization correction factor. In effect, we have estimated the chemical composition by using both photoionization and shock considerations. PMID:10318889

VizieR Online Data Catalog: Pan-Pacific Planet Search (PPPS) I. 7 CMa (Wittenmyer+, 2011)

NASA Astrophysics Data System (ADS)

Wittenmyer, R. A.; Endl, M.; Wang, L.; Johnson, J. A.; Tinney, C. G.; O'Toole, S. J.

2013-05-01

The "Pan-Pacific Planet Search" (PPPS) originated as a Southern Hemisphere extension of the established Lick & Keck Observatory survey for planets orbiting Northern "retired A stars" (Johnson et al. 2006ApJ...652.1724J, 2007ApJ...665..785J, 2010PASP..122..905J). This program is using the 3.9m Anglo-Australian Telescope (AAT) to observe a metal-rich sample of Southern Hemisphere subgiants. Observations for the PPPS began at the AAT in 2009 February. Observing time is scheduled such that each target should receive 4-6 observations per year. PPPS Doppler measurements are made with the UCLES echelle spectrograph (at the 3.9m AAT) which achieves a resolution of 45000 with a 1 arcsec slit. We have observed 7 CMa on 21 epochs, and an iodine-free template observation was obtained on 2010 January 30. Since 7 CMa is an extremely bright star, exposure times ranged from 100 to 500s, with a resulting S/N of ~200-300/pixel each epoch. The data span a total of 917 days and have a mean internal velocity uncertainty of 6.5m/s. (2 data files).

The remarkably high excitation planetary nebula GC 6537.

PubMed

Aller, L H; Hung, S; Feibelman, W A

1999-05-11

NGC 6537 is an unusually high excitation point symmetric planetary nebula with a rich spectrum. Its kinematical structures are of special interest. We are here primarily concerned with the high resolution spectrum as revealed by the Hamilton echelle Spectrograph at Lick Observatory (resolution approximately 0.2 A) and supplemented by UV and near-UV data. These extensive data permit a determination of interstellar extinction, plasma diagnostics, and ionic concentrations. The photoionization models that have been used successfully for many planetary nebulae are not entirely satisfactory here. The plasma electron temperature of a photoionization model cannot much exceed 20,000 K, but plasma diagnostics show that regions emitting radiation of highly ionized atoms such as [NeIV] and [NeV] are much hotter, showing that shock excitation must be important, as suggested by the remarkable kinematics of this object. Hence, instead of employing a strict photoionization model, we are guided by the nebular diagnostics, which reveal how electron temperature varies with ionization potential and accommodates density effects. The predictions of the photoionization model may be useful in estimating ionization correction factor. In effect, we have estimated the chemical composition by using both photoionization and shock considerations.

De-mystifying earned value management for ground based astronomy projects, large and small

NASA Astrophysics Data System (ADS)

Norton, Timothy; Brennan, Patricia; Mueller, Mark

2014-08-01

The scale and complexity of today's ground based astronomy projects have justifiably required Principal Investigator's and their project teams to adopt more disciplined management processes and tools in order to achieve timely and accurate quantification of the progress and relative health of their projects. Earned Value Management (EVM) is one such tool. Developed decades ago and used extensively in the defense and construction industries, and now a requirement of NASA projects greater than $20M; EVM has gained a foothold in ground-based astronomy projects. The intent of this paper is to de-mystify EVM by discussing the fundamentals of project management, explaining how EVM fits with existing principles, and describing key concepts every project can use to implement their own EVM system. This paper also discusses pitfalls to avoid during implementation and obstacles to its success. The authors report on their organization's most recent experience implementing EVM for the GMT-Consortium Large Earth Finder (G-CLEF) project. G-CLEF is a fiber-fed, optical echelle spectrograph that has been selected as a first light instrument for the Giant Magellan Telescope (GMT), planned for construction at the Las Campanas Observatory in Chile's Atacama Desert region.

Solar Cycle 24 UV Radiation: Lowest in more than 6 Decades

NASA Astrophysics Data System (ADS)

Schroder, Klaus-Peter; Mittag, Marco; Schmitt, J. H. M. M.

2015-01-01

Using spectra taken by the robotic telescope ``TIGRE'' (see Fig. 1 and the TIGRE-poster presented by Schmitt et al. at this conference) and its mid-resolution (R=20,000) HEROS double-channel echelle spectrograph, we present our measurements of the solar Ca II H&K chromospheric emission. Using moonlight, we applied the calibration and definition of the Mt. Wilson S-index , which allows a direct comparison with historic observations, reaching back to the early 1960's. At the same time, coming from the same EUV emitting plage regions, the Ca II H&K emission is a good proxy for the latter, which is of interest as a forcing factor in climate models. Our measurements probe the weak, asynchronous activity cycle 24 around its 2nd maximum during the past winter. Our S-values suggest that this maximum is the lowest in chromospheric emission since at least 60 years -- following the longest and deepest minimum since a century. Our observations suggest a similarly long-term (on a scale of decades) low of the far-UV radiation, which should be considered by the next generation of climate models. The current, very interesting activity behaviour calls for a concerted effort on long-term solar monitoring.

VizieR Online Data Catalog: Planetary candidates from 1st yr K2 mission (Vanderburg+, 2016)

NASA Astrophysics Data System (ADS)

Vanderburg, A.; Latham, D. W.; Buchhave, L. A.; Bieryla, A.; Berlind, P.; Calkins, M. L.; Esquerdo, G. A.; Welsh, S.; Johnson, J. A.

2016-02-01

During Campaign 0, K2 observed a field centered at RAJ2000=06:33:11.14,DEJ2000=+21:35:16.40, for a period of 80 days between March and May of 2014. During Campaign 1, K2 observed a field centered at RAJ2000=11:35:45.51,DEJ2000=+01:25:02.28 for 83 days between June and August of 2014. Field 2 of the K2 mission is centered at RAJ2000=16:24:30.34,DEJ2000=-22:26:50.28, and was observed for 79 days between 2014 August and November. Field 3 of the K2 mission is centered at RAJ2000=22:26:39.68,DEJ2000=-11:05:47.99, and was observed for 69 days between 2014 November and 2015 February. We observed 68 stars with the high-resolution Tillinghast Reflector Echelle Spectrograph (TRES; on the 1.5m telescope at Fred L. Whipple Observatory (FLWO) on Mt. Hopkins, Arizona; R=44000) at least once, collecting a total of 101 spectra, and extracted the spectra using the procedure described in Buchhave et al. (2010, J/ApJ/720/1118). See tables 3 and 4. (4 data files).

Ultraviolet observations of the gas phase abundances in the diffuse clouds toward Zeta Ophiuchi at 3.5 kilometers per second resolution

NASA Technical Reports Server (NTRS)

Savage, Blair D.; Cardelli, Jason A.; Sofia, Ulysses J.

1992-01-01

Goddard High Resolution Spectrograph echelle mode measurements at 3.5 km/s resolution are presented for interstellar absorption produced by C II, O I, Mg I, Mg II, Al III, P II, Cr II, Mn II, Fe II, Ni II, Cu II, Zn II, Ga II, Ge II, and Kr I. The absorption line measurements are converted into representations of apparent column density per unit velocity in order to study the multicomponent nature of the absorption. The high spectral resolution of the measurements allows a comparative study of gas phase abundances for many species in the absorbing clouds near -27 and -15 km/s with a typical precision of about 0.05 dex. The matter absorbing near -27 km/s is situated in the local interstellar medium and has log N(H I) of about 19.74. This absorption provides information about the modest 'base' depletion associated with the lower density interstellar medium. The depletion results suggest that accretion processes are operating interstellar clouds that exhibit similar depletion efficiencies for some elements but much higher depletion efficiencies for others.

Opto-mechanical design of the G-CLEF flexure control camera system

NASA Astrophysics Data System (ADS)

Oh, Jae Sok; Park, Chan; Kim, Jihun; Kim, Kang-Min; Chun, Moo-Young; Yu, Young Sam; Lee, Sungho; Nah, Jakyoung; Park, Sung-Joon; Szentgyorgyi, Andrew; McMuldroch, Stuart; Norton, Timothy; Podgorski, William; Evans, Ian; Mueller, Mark; Uomoto, Alan; Crane, Jeffrey; Hare, Tyson

2016-08-01

The GMT-Consortium Large Earth Finder (G-CLEF) is the very first light instrument of the Giant Magellan Telescope (GMT). The G-CLEF is a fiber feed, optical band echelle spectrograph that is capable of extremely precise radial velocity measurement. KASI (Korea Astronomy and Space Science Institute) is responsible for Flexure Control Camera (FCC) included in the G-CLEF Front End Assembly (GCFEA). The FCC is a kind of guide camera, which monitors the field images focused on a fiber mirror to control the flexure and the focus errors within the GCFEA. The FCC consists of five optical components: a collimator including triple lenses for producing a pupil, neutral density filters allowing us to use much brighter star as a target or a guide, a tent prism as a focus analyzer for measuring the focus offset at the fiber mirror, a reimaging camera with three pair of lenses for focusing the beam on a CCD focal plane, and a CCD detector for capturing the image on the fiber mirror. In this article, we present the optical and mechanical FCC designs which have been modified after the PDR in April 2015.

The earthshine s spectra

NASA Astrophysics Data System (ADS)

Montanes Rodriguez, P.; Palle, E.; Goode, P.; Koonin, S.; Hickey, J.; Qiu, J.; Yurchysyn, V.

The Earthshine project, was run by California Institute of Technology (Caltech) between 1993 and 1995. Since 1998, it has been a collaborative effort between Caltech and Big Bear Solar Observatory (BBSO)/New Jersey Institute of Technology (NJIT). Our primary goal is the precise determination of a global and absolutely calibrated Earth's albedo and its synoptic, seasonal, and annual variability; as well as the measurement and investigation of the resolved reflected spectrum of the integrated Earth in the infrared region. The absorption in the infrared region, mainly due to rotational and vibrational transitions of the molecules, show the absorption bands of various telluric and solar components allowing the analysis of the Earth's spectrum such as it would be observed from the outer space. In this paper we present preliminary results of spectroscopic observations, made at Palomar Observatory with the 60-inch telescope's echelle spectrograph. They targeted the visible and near infrared region of the electromagnetic spectrum, and were performed in the spectral range (< 1μm) of the bands of Oxygen A, Oxygen B, water and Hydrogen alpha (H). The first three are typically terrestrial molecular bands. The fourth line, H, is a solar line, used mainly for spectral calibration.

Fiber Mode Scrambler for the Subaru Infrared Doppler Instrument (IRD)

NASA Astrophysics Data System (ADS)

Ishizuka, Masato; Kotani, Takayuki; Nishikawa, Jun; Kurokawa, Takashi; Mori, Takahiro; Kokubo, Tsukasa; Tamura, Motohide

2018-06-01

We report the results of fiber mode scrambler experiments for the Infra-Red Doppler instrument (IRD) on the Subaru 8.2-m telescope. IRD is a fiber-fed, high precision radial velocity (RV) instrument to search for exoplanets around nearby M dwarfs at near-infrared wavelengths. It is a high-resolution spectrograph with an Echelle grating. The expected RV measurement precision is ∼1 m s‑1 with a state of the art laser frequency comb for the wavelength calibration. In IRD observations, one of the most significant instrumental noise is a change of intensity distribution of multi-mode fiber exit, which degrades RV measurement precision. To stabilize the intensity distribution of fiber exit an introduction of fiber mode scrambler is mandatory. Several kinds of mode scramblers have been suggested in previous research, though it is necessary to determine the most appropriate mode scrambler system for IRD. Thus, we conducted systematic measurements of performance for a variety of mode scramblers, both static and dynamic. We tested various length multi-mode fibers, an octagonal fiber, a double fiber scrambler, and two kinds of dynamic scramblers, and their combinations. We report the performances of these mode scramblers and propose candidate mode scrambler systems for IRD.

The Properties of Single Interstellar Clouds: Modified Cycle 1 Observations

NASA Astrophysics Data System (ADS)

Hobbs, Lewis

1990-12-01

WE PROPOSE TO USE THE ECHELLE AND 160M GRATINGS OF THE HIGH RESOLUTION SPECTROGRAPH OVER A TWO-YEAR PERIOD TO OBSERVE THE PROFILES OF INTERSTELLAR ABSORPTION LINES. THE COLUMN DENSITES OF 18 NEUTRAL OR IONIZED FORMS OF THE ELEMENTS C,N,O,Mg,Si,P,S,Fe, AND Zn WILL BE MEASURED IN THE APPROXIMATELY 100 INDIVIDUAL INTERSTELLAR CLOUDS ALONG THE LIGHT PATHS TO 18 BRIGHT, BROAD-LINED STARS OF EARLY SPECTRAL TYPE WITHIN 1 KPC OF THE SUN. THE PRIMARY PURPOSE OF THE OBSERVATIONS IS TO DETERMINE MORE ACCURATELY THAN WAS HITHERTO POSSIBLE THE FUNDAMENTAL PHYSICAL PROPERTIES OF THE RESOLVED CLOUDS, INCLUDING LINEAR SIZE, TEMPERATURE, TOTAL DENSITY, FRACTIONAL IONIZATION AND THE RELATIVE ABUNDANCES OF THE 9 SELECTED ELEMENTS. THE REST OF THIS OBSERVING PROGRAM IS CONTAINED IN APPROVED PROPOSAL ID = 3993; THE PROGRAM ENUMERATED HERE CONSISTS OF THAT PART OF OUR ORIGINAL PROGRAM, ID = 2251, WHICH REQUIRED MODIFICATION IN ORDER TO BE CARRIED OUT USING ONLY SIDE 2 OF THE GHRS. THIS PROGRAM THEREFORE CONSISTS OF ECH-B AND G160M OBSERVATIONS OF EACH OF 8 STARS AT 14 OR MORE WAVELENGTHS. PROGRAMS 2251 AND 3993 SHOULD BE CONSULTED FOR ADDITIONAL DETAILS.

KiwiSpec: The Design and Performance of a High Resolution Echelle Spectrograph for Astronomy

NASA Astrophysics Data System (ADS)

Gibson, Steven Ross

This document describes the design, analysis, construction and testing of KiwiSpec, a fibre-fed, high resolution astronomical spectrograph of an asymmetric white pupil design. The instrument employs an R4, 31.6 groove mm-1 échelle grating for primary dispersion and a 725 lines mm-1 volume phase holographic (VPH) based grism for cross-dispersion. Two versions of the prototype were designed and constructed: an 'in-air' prototype, and a prototype featuring a vacuum chamber (to increase the stability of the instrument). The KiwiSpec optical design is introduced, as well as a description of the theory behind a cross-dispersed échelle spectrograph. The results of tolerancing the optical design are reported for alignment, optical fabrication, and optical surface quality groups of parameters. The optical windows of an iodine cell are also toleranced. The opto-mechanical mounts of both prototypes are described in detail, as is the design of the vacuum chamber system. Given the goal of 1 m/s radial velocity stability, analyses were undertaken to determine the allowable amount of movement of the vacuum windows, and to determine the allowable changes in temperature and pressure within and outside of the vacuum chamber. The spectral efficiency of the instrument was estimated through a predictive model; this was calculated for the as-built instrument and also for an instrument with ideal, high-efficiency coatings. Measurements of the spectral efficiency of various components of the instrument are reported, as well as a description of the measurement system developed to test the efficiency of VPH gratings. On-sky efficiency measurements from use of KiwiSpec on the 1-m McLellan telescope at Mt John University Observatory are reported. Two possible exposure meter locations are explored via an efficiency model, and also through the measurement of the zero-order reflectivity of the échelle grating. Various stability aspects of the design are investigated. These include the stability of the optical mounts with temperature changes, and also the effect of the expansion and contraction of the supporting optical tables. As well, the stability of the in-air prototype was determined through measurement of the movement of thorium-argon emission lines within spectra as the temperature, atmospheric pressure and relative humidity (naturally) varied. Current and planned testing for determining the stability of the vacuum chamber prototype is discussed.

CARMENES: A Spectroscopic Survey of M Dwarfs and their Planets

NASA Astrophysics Data System (ADS)

Quirrenbach, Andreas; Consortium, CARMENES

2015-08-01

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) is a next-generation instrument currently under construction for the 3.5m telescope at the Calar Alto Observatory by a consortium of eleven Spanish and German institutions. Commissioning of CARMENES will start in April 2015. CARMENES will conduct a 600-night exoplanet survey targeting ~300 M dwarfs. An important and unique feature of the CARMENES instrument is that it consists of two separate échelle spectrographs, which together cover the wavelength range from 0.55 to 1.7 μm at a spectral resolution of R = 82,000. The spectrographs are fed by fibers from the Cassegrain focus of the telescope.The main scientific objective of CARMENES is to carry out a survey of late-type main sequence stars with the goal of detecting low-mass planets in their habitable zones (HZs). In the focus of the project are very cool stars later than spectral type M4 and moderately active stars. We aim at being able to detect a 2M⊕ planet in the HZ of an M5 star, which requires a long-term radial velocity precision of 1ms-1 per measurement. For stars later than M4 (M < 0.25M⊙), such precision will yield detections of super-Earths of 5M⊕ and smaller inside the entire width of the HZ. The CARMENES survey will thus provide a comprehensive overview of planetary systems around nearby Northern M dwarfs. By reaching into the realm of Earth-like planets, it will provide a treasure trove for follow-up studies probing their habitability.At the same time, the CARMENES survey will generate a unique data set for studies of M star atmospheres, rotation, and activity. The spectra will cover important diagnostic lines for activity (Hα, Na I D1 and D2, and the Ca II infrared triplet), as well as FeH lines around 10,000Å, from which the magnetic field can be inferred. Correlating the time series of these features with each other, and with wavelength-dependent radial velocities, will provide new insight into the physical properties of M dwarf atmospheres, and will provide excellent discrimination between planetary companions and stellar radial velocity "noise".

How accurately can we measure the water vapour content with astronomical spectra?

NASA Astrophysics Data System (ADS)

Kausch, Wolfgang; Noll, Stefan; Smette, Alain; Kimeswenger, Stefan; Kerber, Florian; Jones, Amy M.; Szyszka, Cezary; Unterguggenberger, Stefanie

2014-05-01

Light from astronomical objects unavoidably has to pass through the Earth's atmosphere when being observed by ground-based telescopes. Thus, the fingerprint of the atmospheric state at the time of the observation is present in any spectrum taken by astronomical spectrographs due to absorption and emission arising in the atmosphere. The Very Large Telescope (VLT), operated by the European Southern Observatory, is one of the world's largest telescope facilities located at Cerro Paranal in the Chilean Atacama Desert offering a wide selection of various instruments. One of the most versatile instruments is X-Shooter. This medium resolution Echelle spectrograph covers the entire wavelength regime from 0.3 to 2.5 μm and is mounted on one of the 8m-class telescopes of the VLT. Due to its versatility, it is widely used, which leads to a good temporal coverage. We have recently developed the software package molecfit, a tool used to model and correct for atmospheric absorption lines visible in astronomical spectra. It is based on the radiative transfer code LBLRTM, the HITRAN line parameter database, the GDAS atmospheric profiles, and local meteorological data. A by-product is the determination of the amount of precipitable water vapour (PWV) above the observatory, as well as several other molecules, including CO2. In this poster, we investigate the accuracy of this method. We have used a set of X-Shooter spectra of so-called telluric standard stars, which are hot and bright stars showing nearly no intrinsic spectral features in the near infrared regime. Thus, most absorption features present in these spectra are related to the absorption arising in the Earth's atmosphere. For each spectrum, we have determined the PWV with our molecfit code and compared it with direct measurements achieved by the LHATPRO radiometer recently installed at Cerro Paranal. Therefore we have extended the results obtained by Kerber et al. (2012, Proc. SPIE, 8446) on a long time scale. Due to the wide wavelength coverage of X-Shooter, the atmospheric content of CO2 can also successfully be determined. The good accuracy obtained by this method confirms that regular monitoring for a number of other molecules by the various spectrographs installed on the Very Large Telescope is possible.

Characterization of members to stellar kinematic groups using chemical tagging

NASA Astrophysics Data System (ADS)

Tabernero, H. M.

2014-10-01

In this thesis we have characterized more than one thousand late-type stars. For this characterization we have been making use of high resolution spectroscopy (R > 40,000) taken in different spectrographs, HERMES at the Mercator telescope in La Palma, FOCES in the 2.2m telescope at Calar Alto, the Coudé-Echelle spectrograph at 2 m-the Alfred- Jensch-Teleskop in Tautenburg, and UVES at the Very Large Telescope in La Silla. Stellar spectroscopy, in particular at high-resolution, is a modern tool that allows us to extract a lot of information of a given star. In particular, we have obtained their atmospheric parameters, namely: effective temperature (Teff), surface gravity (log g), microturbulent velocity (ξ), and iron abundance ([Fe/H], used as a metallicity proxy). An automatic code (StePar) has been developed. This code allows to derive stellar atmospheric parameters (Teff , log g, ξ, and [Fe/H]) only in a few minutes. Also, with these parameters at hand we have derived chemical abundances for 20 different chemical elements: Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Ba, Ce, and Nd, which offer many or at least some isolated transitions in the wavelength range of the spectra taken with these spectrographs. This work comprises two publications in Astronomy & Astrophysics. The first one is about chemical tagging applied to the Hyades SC (see Chapter 2 or Tabernero et al. 2012). The second paper is a in-depth study of the chemical composition of candidate members to the Ursa Major MG (see Chapter 3 or Tabernero et al. 2015). Additionally there is another chapter that comprises the analysis of Galactic stars within the GAIA ESO Survey stars (GES, Gilmore et al. 2012; Randich & Gilmore 2013) whose data have contributed to the publication of some release (Lanzafame et al. 2014; Smiljanic et al. 2014) and science papers (Jofre et al. 2014; Sousa et al. 2014; Spina et al. 2014a,b) that made use the survey results. The two papers included in this thesis deal with the characterization of late-type stars (F, G, and K spectral types). In particular, this thesis is based on the determination of stellar atmospheric parameters and element abundances.

VizieR Online Data Catalog: Solar neighborhood. XXXVII. RVs for M dwarfs (Benedict+, 2016)

NASA Astrophysics Data System (ADS)

Benedict, G. F.; Henry, T. J.; Franz, O. G.; McArthur, B. E.; Wasserman, L. H.; Jao, W.-C.; Cargile, P. A.; Dieterich, S. B.; Bradley, A. J.; Nelan, E. P.; Whipple, A. L.

2017-05-01

During this project we observed with two Fine Guidance Sensor (FGS) units: FGS 3 from 1992 to 2000, and FGS 1r from 2000 to 2009. FGS 1r replaced the original FGS 1 during Hubble Space Telescope (HST) Servicing Mission 3A in late 1999. We included visual, photographic, and CCD observations of separations and position angles from Geyer et al. 1988AJ.....95.1841G for our analysis of GJ 65 AB. We include a single observation of G 193-027 AB from Beuzit et al. 2004A&A...425..997B, who used the Adaptive Optics Bonnette system on the Canada-France-Hawaii Telescope (CFHT). For GJ 65 AB we include five Very Large Telescope/NAos-COnica (VLT/NACO) measures of position angle and separation (Kervella et al. 2016A&A...593A.127K). For our analysis of GJ 623 AB, we included astrometric observations (Martinache et al. 2007ApJ...661..496M) performed with the Palomar High Angular Resolution Observer (PHARO) instrument on the Palomar 200in (5m) telescope and with the Near InfraRed Camera 2 (NIRC2) instrument on the Keck II telescope. Separations have typical errors of 2mas. Position angle errors average 0.5°. Measurements are included for GJ 22 AC from McCarthy et al. 1991AJ....101..214M and for GJ 473 AB from Henry et al. 1992AJ....103.1369H and Torres et al. 1999AJ....117..562T, who used a two-dimensional infrared speckle camera containing a 58*62 pixel InSb array on the Steward Observatory 90in telescope. We also include infrared speckle observations by Woitas et al. 2003A&A...406..293W, who obtained fourteen separation and position angle measurements for GJ 22 AC with the near-infrared cameras MAGIC and OMEGA Cass at the 3.5m telescope on Calar Alto. We also include a few speckle observations at optical wavelengths from the Special Astrophysical Observatory 6m Bolshoi Azimuth Telescope (BTA) and 1m Zeiss (Balega et al. 1994, Cat. J/A+AS/105/503), from the CFHT (Blazit et al. 1987) and from the Differential Speckle Survey Instrument (DSSI) on the Wisconsin, Indiana, Yale, National optical astronomy observatory (WIYN) 3.5m (Horch et al. 2012, Cat. J/AJ/143/10). Where available, we use astrometric observations from HST instruments other than the FGSs, including the Faint Object Camera (FOC; Barbieri et al. 1996A&A...315..418B), the Faint Object Spectrograph (FOS; Schultz et al. 1998PASP..110...31S), the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS; Golimowski et al. 2004AJ....128.1733G), and the Wide-Field Planetary Camera 2 (WFPC2; Schroeder et al. 2000AJ....119..906S; Dieterich et al. 2012, Cat. J/AJ/144/64). Our radial velocity measurements, listed in table3, are from two sources. We obtained most radial velocity data with the McDonald 2.1m Struve telescope and the Sandiford Cassegrain Echelle spectrograph, hereafter CE. The CE delivers a dispersion equivalent to 2.5km/s/pix (R=λ/Δλ=60000) with a wavelength range of 5500{<=}λ{<=}6700Å spread across 26 orders (apertures). The McDonald data were collected during 33 observing runs from 1995 to 2009. Some GJ 623 AB velocities came from the Hobby-Eberly Telescope (HET) using the Tull Spectrograph. (3 data files).

The Sharjah Center for Astronomy and Space Sciences (SCASS 2015): Concept and Resources

NASA Astrophysics Data System (ADS)

Naimiy, Hamid M. K. Al

2015-08-01

The Sharjah Center for Astronomy and Space Sciences (SCASS) was launched this year 2015 at the University of Sharjah in the UAE. The center will serve to enrich research in the fields of astronomy and space sciences, promote these fields at all educational levels, and encourage community involvement in these sciences. SCASS consists of:The Planetarium: Contains a semi-circle display screen (18 meters in diameter) installed at an angle of 10° which displays high-definition images using an advanced digital display system consisting of seven (7) high-performance light-display channels. The Planetarium Theatre offers a 200-seat capacity with seats placed at highly calculated angles. The Planetarium also contains an enormous star display (Star Ball - 10 million stars) located in the heart of the celestial dome theatre.The Sharjah Astronomy Observatory: A small optical observatory consisting of a reflector telescope 45 centimeters in diameter to observe the galaxies, stars and planets. Connected to it is a refractor telescope of 20 centimeters in diameter to observe the sun and moon with highly developed astronomical devices, including a digital camera (CCD) and a high-resolution Echelle Spectrograph with auto-giving and remote calibration ports.Astronomy, space and physics educational displays for various age groups include:An advanced space display that allows for viewing the universe during four (4) different time periods as seen by:1) The naked eye; 2) Galileo; 3) Spectrographic technology; and 4) The space technology of today.A space technology display that includes space discoveries since the launching of the first satellite in 1940s until now.The Design Concept for the Center (450,000 sq. meters) was originated by HH Sheikh Sultan bin Mohammed Al Qasimi, Ruler of Sharjah, and depicts the dome as representing the sun in the middle of the center surrounded by planetary bodies in orbit to form the solar system as seen in the sky.

Detection of a very low mass star in an eclipsing binary system

NASA Astrophysics Data System (ADS)

Chaturvedi, Priyanka; Chakraborty, Abhijit; Anandarao, B. G.; Roy, Arpita; Mahadevan, Suvrath

2016-10-01

We report the detection of a very low mass star (VLMS) companion to the primary star 1SWASP J234318.41+295556.5A (J2343+29A), using radial velocity (RV) measurements from the PARAS (PRL Advanced Radial-velocity Abu-sky Search) high-resolution echelle spectrograph. The periodicity of the single-lined eclipsing binary (SB1) system, as determined from 20 sets of RV observations from PARAS and 6 supporting sets of observations from SOPHIE data, is found to be 16.953 d as against the 4.24 d period reported from SuperWASP photometry. It is likely that inadequate phase coverage of the transit with SuperWASP photometry led to the incorrect determination of the period for this system. We derive the spectral properties of the primary star from the observed stellar spectra: Teff = 5125 ± 67 K, [Fe/H] = 0.1 ± 0.14 and logg = 4.6 ± 0.14, indicating a K1V primary. Applying the Torres relation to the derived stellar parameters, we estimate a primary mass 0.864_{-0.098}^{+0.097} M⊙ and a radius of 0.854_{-0.060}^{+0.050} R⊙. We combine RV data with SuperWASP photometry to estimate the mass of the secondary, MB = 0.098 ± 0.007 M⊙, and its radius, RB = 0.127 ± 0.007 R⊙, with an accuracy of ˜7 per cent. Although the observed radius is found to be consistent with the Baraffe's theoretical models, the uncertainties on the mass and radius of the secondary reported here are model dependent and should be used with discretion. Here, we establish this system as a potential benchmark for the study of VLMS objects, worthy of both photometric follow-up and the investment of time on high-resolution spectrographs paired with large-aperture telescopes.

High Spectral Resolution SOFIA/EXES Observations of C2H2 toward Orion IRc2

NASA Astrophysics Data System (ADS)

Rangwala, Naseem; Colgan, Sean W. J.; Le Gal, Romane; Acharyya, Kinsuk; Huang, Xinchuan; Lee, Timothy J.; Herbst, Eric; deWitt, Curtis; Richter, Matt; Boogert, Adwin; McKelvey, Mark

2018-03-01

We present high spectral resolution observations from 12.96 to 13.33 microns toward Orion IRc2 using the mid-infrared spectrograph, Echelon-Cross-Echelle Spectrograph (EXES), at Stratospheric Observatory for Infrared Astronomy (SOFIA). These observations probe the physical and chemical conditions of the Orion hot core, which is sampled by a bright, compact, mid-infrared background continuum source in the region, IRc2. All 10 of the rovibrational C2H2 transitions expected in our spectral coverage are detected with high signal-to-noise ratios (S/Ns), yielding continuous coverage of the R-branch lines from J = 9–8 to J = 18–17, including both ortho and para species. Eight of these rovibrational transitions are newly reported detections. The isotopologue, 13CCH2, is clearly detected with a high S/N. This enabled a direct measurement of the 12C/13C isotopic ratio for the Orion hot core of 14 ± 1 and an estimated maximum value of 21. We also detected several HCN rovibrational lines. The ortho and para C2H2 ladders are clearly separate, and tracing two different temperatures, 226 K and 164 K, respectively, with a non-equilibrium ortho to para ratio (OPR) of 1.7 ± 0.1. Additionally, the ortho and para V LSR values differ by about 1.8 ± 0.2 km s‑1, while the mean line widths differ by 0.7 ± 0.2 km s‑1, suggesting that these species are not uniformly mixed along the line of sight to IRc2. We propose that the abnormally low C2H2 OPR could be a remnant from an earlier, colder phase, before the density enhancement (now the hot core) was impacted by shocks generated from an explosive event 500 years ago.

Effect of geomagnetic storms on the daytime low-latitude thermospheric wave dynamics

NASA Astrophysics Data System (ADS)

Karan, Deepak K.; Pallamraju, Duggirala

2018-05-01

The equatorial- and low-latitude thermospheric dynamics is affected by both equatorial electrodynamics and neutral wave dynamics, the relative variation of which is dependent on the prevalent background conditions, which in turn has a seasonal dependence. Depending on the ambient thermospheric conditions, varying effects of the geomagnetic disturbances on the equatorial- and low-latitude thermosphere are observed. To investigate the effect of these disturbances on the equatorial- and low-latitude neutral wave dynamics, daytime airglow emission intensities at OI 557.7 nm, OI 630.0 nm, and OI 777.4 nm are used. These emissions from over a large field-of-view (FOV∼1000) have been obtained using a high resolution slit spectrograph, MISE (Multiwavelength Imaging Spectrograph using Echelle grating), from a low-latitude location, Hyderabad (17.50N, 78.40E; 8.90N MLAT), in India. Variations of the dayglow emission intensities are investigated during three geomagnetic disturbance events that occurred in different seasons. It is seen that the neutral dayglow emission intensities at all the three wavelengths showed different type of variations with the disturbance storm time (Dst) index in different seasons. Even though the dayglow emission intensities over low-latitude regions are sensitive to the variation in the equatorial electric fields, during periods of geomagnetic disturbances, especially in solstices, these are dependent on thermospheric O/N2 values. This shows the dominance of neutral dynamics over electrodynamics in the low-latitude upper atmosphere during geomagnetic disturbances. Further, spectral analyses have been carried out to obtain the zonal scale sizes in the gravity wave regime and their diurnal distributions are compared for geomagnetic quiet and disturbed days. Broadly, the zonal scales seem to be breaking into various scale sizes on days of geomagnetic disturbances when compared to those on quiet days. This contrast in the diurnal distribution of the zonal scale sizes brings to light, for the first time, the varying nature of the neutral wave coupling in the daytime thermosphere during periods of geomagnetic disturbances.

Kinematic structure of the 30 Doradus giant H II region

NASA Technical Reports Server (NTRS)

Chu, You-Hua; Kennicutt, Robert C., Jr.

1994-01-01

We have used the echelle CCD spectrograph on the Cerro Tololo Inter-American Observatory (CTIO) 4 m telescope to map the nebular velocity field in the 30 Doradus giant H II region. The kinematics of 30 Dor are very complex. The outer regions are charaterized by a smooth velocity field, but its turbulent velocity, 30-40 km/s Full Width Half Maximum (FWHM), is considerably higher than those in most smaller H II regions. In the central 9 min core, multiple velocity components are observed at most positions. The velocity field is dominated by a large number of expanding structures, ranging in size from 1 to 100 pc and expansion velocities of 20-200 km/s, and often organized into large hierarchical networks. The integral of these complex expanding structures in 30 Dor produces a surprisingly simple profile with a broad Gaussian core and faint extended wings. Several fast-expanding shells, with diameters of 2-20 pc, expansion velocities of 100-300 km/s, and kinetic energies of 0.5-10 x 10(exp 50) ergs have been identified. The large fast-expanding shells and networks are coincident with extended X-ray sources and are probably associated with supernova remnants embedded in supershells produced by the combined effects of stellar winds and supernovae from OB associations. We have used the intensity-calibrated echelle spectra to determine the basic physical and dynamical properties of the kinematic features in 30 Dor. The expanding shells contain roughly half of the kinetic energy in the 30 Dor complex, and this energy is several times higher than the gravitational binding energy of the region. The energetic requirements of the gas are consistent with the observed stellar content of 30 Dor, if the gas is accelerated by a combination of stellar winds and supernovae. Extrapolating the current energy injection rate in the nebula over the lifetime of the OB complex suggest that 30 Dor and its vicinity will evolve into a supergiant shell as seen in the LMC and other nearby galaxies.

The Spite Lithium Plateau: Ultrathin but Postprimordial

NASA Astrophysics Data System (ADS)

Ryan, Sean G.; Norris, John E.; Beers, Timothy C.

1999-10-01

We have studied 23 very metal-poor field turnoff stars, specifically chosen to enable a precise measurement of the dispersion in the lithium abundance of the Spite Li plateau. We concentrated on stars having a narrow range of effective temperature and very low metallicities ([Fe/H]<~-2.5) to reduce the effects of systematic errors and have made particular efforts to minimize random errors. A typical statistical error for our abundances is 0.033 dex (1 σ), which represents a factor of 2 improvement on most previous studies. Our sample does not exhibit a trend with effective temperature, although the temperature range is limited. However, for -3.6<[Fe/H]<-2.3 we do recover a dependence on metallicity at dA(Li)/d[Fe/H]=0.118+/-0.023 (1 σ) dex per dex, almost the same level as discussed previously. Earlier claims for a lack of dependence of A(Li) on abundance are shown to have arisen probably from noisier estimates of effective temperatures and metallicities, which have erased the real trend. The dependence is concordant with theoretical predictions of Galactic chemical evolution (GCE) of Li (even in such metal-poor stars) and with the published level of 6Li in two of the stars of our sample, which we use to infer the GCE 7Li contribution. One of the 23 stars, G186-26, was known already to be strongly Li-depleted. Of the remaining 22 objects, 21 have abundances consistent with an observed spread about the metallicity trend of a mere 0.031 dex (1 σ). Because the formal errors are 0.033 dex, we conclude that the intrinsic spread is effectively zero at the very metal-poor halo turnoff. This is established at much higher precision than previous studies (~0.06-0.08 dex). The essentially zero intrinsic spread leads to the conclusion that either these stars have all changed their surface Li abundances very uniformly, or else they exhibit close to the primordial abundance sought for its cosmological significance. We cannot rule out a uniform depletion mechanism, but economy of hypothesis supports the latter interpretation. The lack of spread in the A(Li) abundances limits permissible depletion by rotationally induced mixing models to less than 0.1 dex. Correcting for the GCE contribution to both 6Li and 7Li, we infer a primordial abundance A(Li)p~=2.00 dex, with three systematic uncertainties of up to 0.1 dex each depending on uncertainties in the effective temperature scale, stellar atmosphere models, and correction for GCE. (This value rests on an effective-temperature zero-point set by Magain's and Bell & Oke's b-y calibrations of metal-poor stars and the model atmospheres without convective overshoot.) We predict that observations of Li in extremely low-metallicity stars, having [Fe/H]<-3, will yield smaller A(Li) values than the bulk of stars in this sample, consistent with a low primordial abundance. The difference between our field star observations and published M92 data suggests real field-to-cluster differences. This may indicate different angular momentum evolutionary histories, with interactions between protostellar disks in the dense globular cluster environments possibly being responsible. Further study of Li in globular clusters and in very metal-poor field samples is required to clarify the situation. Based on observations obtained with the University College London echelle spectrograph (UCLES) on the 3.9 m Anglo-Australian Telescope (AAT), the Double Beam Spectrograph (DBS) on the Australian National University 2.3 m telescope, and the Utrecht echelle spectrograph (UES) on the 4.2 m William Herschel Telescope (WHT).

Developpement D'un Modele Climatique Regional: Fizr Simulation des Conditions de Janvier de la Cote Ouest Nord Americaine

NASA Astrophysics Data System (ADS)

Goyette, Stephane

1995-11-01

Le sujet de cette these concerne la modelisation numerique du climat regional. L'objectif principal de l'exercice est de developper un modele climatique regional ayant les capacites de simuler des phenomenes de meso-echelle spatiale. Notre domaine d'etude se situe sur la Cote Ouest nord americaine. Ce dernier a retenu notre attention a cause de la complexite du relief et de son controle sur le climat. Les raisons qui motivent cette etude sont multiples: d'une part, nous ne pouvons pas augmenter, en pratique, la faible resolution spatiale des modeles de la circulation generale de l'atmosphere (MCG) sans augmenter a outrance les couts d'integration et, d'autre part, la gestion de l'environnement exige de plus en plus de donnees climatiques regionales determinees avec une meilleure resolution spatiale. Jusqu'alors, les MCG constituaient les modeles les plus estimes pour leurs aptitudes a simuler le climat ainsi que les changements climatiques mondiaux. Toutefois, les phenomenes climatiques de fine echelle echappent encore aux MCG a cause de leur faible resolution spatiale. De plus, les repercussions socio-economiques des modifications possibles des climats sont etroitement liees a des phenomenes imperceptibles par les MCG actuels. Afin de circonvenir certains problemes inherents a la resolution, une approche pratique vise a prendre un domaine spatial limite d'un MCG et a y imbriquer un autre modele numerique possedant, lui, un maillage de haute resolution spatiale. Ce processus d'imbrication implique alors une nouvelle simulation numerique. Cette "retro-simulation" est guidee dans le domaine restreint a partir de pieces d'informations fournies par le MCG et forcee par des mecanismes pris en charge uniquement par le modele imbrique. Ainsi, afin de raffiner la precision spatiale des previsions climatiques de grande echelle, nous developpons ici un modele numerique appele FIZR, permettant d'obtenir de l'information climatique regionale valide a la fine echelle spatiale. Cette nouvelle gamme de modeles-interpolateurs imbriques qualifies d'"intelligents" fait partie de la famille des modeles dits "pilotes". L'hypothese directrice de notre etude est fondee sur la supposition que le climat de fine echelle est souvent gouverne par des forcages provenant de la surface plutot que par des transports atmospheriques de grande echelle spatiale. La technique que nous proposons vise donc a guider FIZR par la Dynamique echantillonnee d'un MCG et de la forcer par la Physique du MCG ainsi que par un forcage orographique de meso-echelle, en chacun des noeuds de la grille fine de calculs. Afin de valider la robustesse et la justesse de notre modele climatique regional, nous avons choisi la region de la Cote Ouest du continent nord americain. Elle est notamment caracterisee par une distribution geographique des precipitations et des temperatures fortement influencee par le relief sous-jacent. Les resultats d'une simulation d'un mois de janvier avec FIZR demontrent que nous pouvons simuler des champs de precipitations et de temperatures au niveau de l'abri beaucoup plus pres des observations climatiques comparativement a ceux simules a partir d'un MCG. Ces performances sont manifestement attribuees au forcage orographique de meso-echelle de meme qu'aux caracteristiques de surface determinees a fine echelle. Un modele similaire a FIZR peut, en principe, etre implante sur l'importe quel MCG, donc, tout organisme de recherche implique en modelisation numerique mondiale de grande echelle pourra se doter d'un el outil de regionalisation.

Spectroscopic classification of AT2018aes as a supernova impostor

NASA Astrophysics Data System (ADS)

Andrews, Jennifer; Smith, Nathan; Van Dyk, Schuyler D.

2018-03-01

A visual-wavelength optical spectrum of AT2018aes obtained on UT 2018 Mar 13 (JD 2458190.84) with the Magellan Clay telescope (+ LDSS3 spectrograph, VPH-all grism) reveals a narrow H-alpha emission line with a velocity of 525 km/s, with wings extending to roughly +/-1000 km/s.

New measurements of D/H on Mars using EXES aboard SOFIA

NASA Astrophysics Data System (ADS)

Encrenaz, T.; DeWitt, C.; Richter, M. J.; Greathouse, T. K.; Fouchet, T.; Montmessin, F.; Lefèvre, F.; Bézard, B.; Atreya, S. K.; Aoki, S.; Sagawa, H.

2018-05-01

The global D/H ratio on Mars is an important measurement for understanding the past history of water on Mars; locally, through condensation and sublimation processes, it is a possible tracer of the sources and sinks of water vapor on Mars. Measuring D/H as a function of longitude, latitude and season is necessary for determining the present averaged value of D/H on Mars. Following an earlier measurement in April 2014, we used the Echelon Cross Echelle Spectrograph (EXES) instrument on board the Stratospheric Observatory for Infrared Astronomy (SOFIA) facility to map D/H on Mars on two occasions, on March 24, 2016 (Ls = 127°), and January 24, 2017 (Ls = 304°), by measuring simultaneously the abundances of H2O and HDO in the 1383-1391 cm-1 range (7.2 μm). The D/H disk-integrated values are 4.0 (+0.8, -0.6) × Vienna Standard Mean Ocean Water (VSMOW) and 4.5 (+0.7, -0.6) × VSMOW, respectively, in agreement with our earlier result. The main result of this study is that there is no evidence of strong local variations in the D/H ratio nor for seasonal variations in the global D/H ratio between northern summer and southern summer.

Optical Spectrum of the Compact Planetary Nebula IC 5117

NASA Technical Reports Server (NTRS)

Hyung, Siek; Aller, Lawrence H.; Feibelman, Walter A.; Lee, Seong-Jae; Fisher, Richard R. (Technical Monitor)

2001-01-01

High resolution spectroscopic data of the very compact planetary nebula IC 5117 are obtained in the optical wavelengths, 3700A - 10050A, with the Hamilton Echelle Spectrograph at Lick Observatory, and which have been analyzed along with the International Ultraviolet Explorer (IUE) UV archive data. Although a diagnostic diagram shows significant density and temperature fluctuations, our analysis indicates that the nebular gas may be represented by a homogeneous shell of extremely high density gas, N(sub epsilon) approx. 90 000 /cu cm. The average electron temperatures, e.g. indicated by the [OIII] diagnostics, are around 12 000 K. We construct a photoionization model to represent most of the observed line intensities, and the physical condition of this compact nebulosity. Based on the semi-empirical ionization correction approach, and model indications, we derived the elemental abundances: He, C, N, O, Ne, and Ar appear to be normal or marginally depleted compared to the average planetary nebula, while the remaining elements, S, Cl, and K appear to be enhanced. IC 5117 is perhaps a very young compact planetary nebula, slightly more evolved than the other well-known compact planetary nebula IC 4997. The central stellar temperature is likely to be around 120 000 K, evolved from a C-rich AGB progenitor.

N III Bowen Lines and Fluorescence Mechanism in the Symbiotic Star AG Peg

NASA Astrophysics Data System (ADS)

Hyung, Siek; Lee, Seong-Jae; Lee, Kang Hwan

2018-03-01

We have investigated the intensities and full width at half maximum (FWHM) of the high dispersion spectroscopic N III emission lines of AG Peg, observed with the Hamilton Echelle Spectrograph (HES) in three different epochs at Mt. Hamilton's Lick Observatory. The earlier theoretical Bowen line study assumed the continuum fluorescence effect, presenting a large discrepancy with the present data. Hence, we analyzed the observed N III lines assuming line fluorescence as the only suitable source: (1) The O III and N III resonance line profiles near λ 374 were decomposed, using the Gaussian function, and the contributions from various O III line components were determined. (2) Based on the theoretical resonant N III intensities, the expected N III Bowen intensities were obtained to fit the observed values. Our study shows that the incoming line photon number ratio must be considered to balance at each N III Bowen line level in the ultraviolet radiation according to the observed lines in the optical zone. We also found that the average FWHM of the N III Bowen lines was about 5 km·s-1 greater than that of the O III Bowen lines, perhaps due to the inherently different kinematic characteristics of their emission zones.

Carbon Chemistry in IRC+10216: Infrared Detection of Diacetylene

PubMed Central

Fonfría, J. P.; Agúndez, M.; Cernicharo, J.; Richter, M. J.; Lacy, J. H.

2018-01-01

We present the detection of C4H2 for first time in the envelope of the C-rich AGB star IRC+10216 based on high spectral resolution mid-IR observations carried out with the Texas Echelon-cross-Echelle Spectrograph (TEXES) mounted on the Infrared Telescope Facility (IRTF). The obtained spectrum contains 24 narrow absorption features above the detection limit identified as lines of the ro-vibrational C4H2 band ν6+ν8(σu+). The analysis of these lines through a ro-vibrational diagram indicates that the column density of C4H2 is (2.4 ± 1.5) × 1016 cm−2. Diacetylene is distributed in two excitation populations accounting for 20 and 80% of the total column density and with rotational temperatures of 47 ± 7 and 420 ± 120 K, respectively. This two-folded rotational temperature suggests that the absorbing gas is located beyond ≃0·"4≃20R⋆ from the star with a noticeable cold contribution outwards from ≃ 10″ ≃ 500R⋆. This outer shell matches up with the place where cyanoacetylenes and carbon chains are known to form due to the action of the Galactic dissociating radiation field on the neutral gas coming from the inner layers of the envelope. PMID:29882548

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richer, Michael G.; Suárez, Genaro; López, José Alberto

We present spectroscopic observations of the C ii λ 6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir. We study the kinematics of the C ii λ 6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C ii λ 6578 line are not those expected if this line arises from the recombination of C{sup 2+} ions ormore » the fluorescence of C{sup +} ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in H α line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.« less

A young solar twin in the Rosette cluster NGC 2244 line of sight

NASA Astrophysics Data System (ADS)

Huber, Jeremy M.; Kielkopf, John F.; Mengel, Matthew; Carter, Bradley D.; Ferland, Gary J.; Clark, Frank O.

2018-05-01

Based on prior precision photometry and cluster age analysis, the bright star GSC 00154-01819 is a possible young pre-main sequence member of the Rosette cluster, NGC 2244. As part of a comprehensive study of the large-scale structure of the Rosette and its excitation by the cluster stars, we noted this star as a potential backlight for a probe of the interstellar medium and extinction along the sight line towards a distinctive nebular feature projected on to the cluster centre. New high-resolution spectra of the star were taken with the University College London Echelle Spectrograph of the AAT. They reveal that rather than being a reddened spectral type B or A star within the Mon OB2 association, it is a nearby, largely unreddened, solar twin of spectral type G2V less than 180 Myr old. It is about 219 pc from the Sun with a barycentric radial velocity of +14.35 ± 1.99 km s-1. The spectrum of the Rosette behind it and along this line of sight shows a barycentric radial velocity of +26.0 ± 2.4 km s-1 in H α, and a full width at half-maximum velocity dispersion of 61.94 ± 1.38 km s-1.

Second COS FUV Lifetime Position: Verification of FUV Bright Object Aperture (BOA) Operations (FCAL4)

NASA Astrophysics Data System (ADS)

Debes, John H.

2013-05-01

As part of the calibration of the second lifetime position on the Cosmic Origins Spectrograph (COS) far-ultraviolet (FUV) detectors, observations of the external target, G191-B2B, were obtained with the G130M, G160M, and G140L gratings in combi- nation with the Bright Object Aperture. The observations were designed to verify the performance of these spectroscopic modes by reproducing similar observations taken during the SM4 Servicing Mission Observatory Verification (SMOV) of COS. These observations allowed for a detailed determination of the spatial location and profile of the spectra from the three gratings, as well as a determination of the spectral resolution of the G130M grating prior to and after the lifetime move. In general, the negligi- ble differences which exist between the two lifetime positions can be attributed to slight differences in the optical path. In particular, the spectral resolution appears to be slightly improved. The stability of the absolute and relative flux calibration was investigated for G130M as well using STIS echelle data of G191-B2B. We determine that the COS ab- solute flux calibration with the BOA is accurate to 10%, and flux calibrated data are reproducible at the 1-2% level since SMOV.

Carbon Chemistry in IRC+10216: Infrared Detection of Diacetylene

NASA Astrophysics Data System (ADS)

Fonfría, J. P.; Agúndez, M.; Cernicharo, J.; Richter, M. J.; Lacy, J. H.

2018-01-01

We present the detection of C4H2 for first time in the envelope of the C-rich AGB star IRC+10216, based on high spectral resolution mid-infrared observations carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the Infrared Telescope Facility. The obtained spectrum contains 24 narrow absorption features above the detection limit, identified as lines of the ro-vibrational C4H2 band {ν }6+{ν }8({σ }u+). The analysis of these lines through a ro-vibrational diagram indicates that the column density of C4H2 is (2.4 ± 1.5) × 1016 cm‑2. Diacetylene is distributed in two excitation populations accounting for 20% and 80% of the total column density and with rotational temperatures of 47 ± 7 and 420 ± 120 K, respectively. This two-folded rotational temperature suggests that the absorbing gas is located beyond ≃0.″4 ≃ 20 R ⋆ from the star, with a noticeable cold contribution outwards from ≃10″ ≃ 500 R ⋆. This outer shell matches up with the place where cyanoacetylenes and carbon chains are known to form due to the action of the Galactic dissociating radiation field on the neutral gas coming from the inner layers of the envelope.

Laboratory measurements of modal noise on optical fiber

NASA Astrophysics Data System (ADS)

Iuzzolino, M.; Sanna, N.; Tozzi, A.; Oliva, E.

Many scientific instruments are nowadays coupled to the telescope through optical fibers. This is also the case of the current configuration of GIANO, the high resolution near infrared echelle spectrograph installed at the TNG telescope. As experienced and frequent users of the IR optical fiber, the GIANO building team decided to go deep in the characterization of the optical fiber in the IR band, and in particular to understand and analyze the fiber modal noise. This work is also a preparatory study for the future HIRES@E-ELT instrument design. This paper consists in the description of the fiber laboratory tests, and in the explanation of the results. The whole job defines a wider comprehension of the modal noise, and demonstrates the existence of two aspects influencing this noise. The first one, well known in literature, refers to the interferences between the fiber modes at the exit endface of the fiber, and it can be mitigated by mechanical scrambling techniques. The second one, unknown before, is entirely dependent on the way in which light is injected at the entrance of the fiber, and no mitigation have been observed with any classical scrambling technique (e.g. double-scramblers). These considerations apply to both ZBLAN or fused silica optical fiber, and to both circular and octagonal core shape.

A PROFILE ANALYSIS OF RAMAN-SCATTERED O VI BANDS AT 6825 Å AND 7082 Å IN SANDULEAK’S STAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heo, Jeong-Eun; Lee, Hee-Won; Angeloni, Rodolfo

2016-12-20

We present a detailed modeling of the two broad bands observed at 6825 and 7082 Å in Sanduleak’s star, a controversial object in the Large Magellanic Cloud. These bands are known to originate from Raman scattering of O vi  λ λ 1032 and 1038 photons with atomic hydrogen and are only observed in bona fide symbiotic stars. Our high-resolution spectrum obtained with the Magellan Inamori Kyocera Echelle spectrograph at the Magellan-Clay Telescope reveals, quite surprisingly, that the profiles of the two bands look very different: while the Raman 6825 Å band shows a single broad profile with a redward extendedmore » bump, the Raman 7082 Å band exhibits a distinct triple-peak profile. Our model suggests that the O vi emission nebula can be decomposed into a red, blue, and central emission region from an accretion disk, a bipolar outflow, and a further compact, optically thick region. We also perform Monte Carlo simulations with the aim of fitting the observed flux ratio F (6825)/ F (7082) ∼ 4.5, which indicates that the neutral region in Sanduleak’s star is characterized by the column density N{sub Hi} ∼ 1 × 10{sup 23} cm{sup −2}.« less

The RRc Stars: Chemical Abundances and Envelope Kinematics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sneden, Christopher; Adamów, Monika; Preston, George W.

2017-10-10

We analyzed series of spectra obtained for 12 stable RRc stars observed with the echelle spectrograph of the du Pont telescope at Las Campanas Observatory and we analyzed the spectra of RRc Blazhko stars discussed by Govea et al. We derived model atmosphere parameters, [Fe/H] metallicities, and [X/Fe] abundance ratios for 12 species of 9 elements. We co-added all spectra obtained during the pulsation cycles to increase signal to noise and demonstrate that these spectra give results superior to those obtained by co-addition in small phase intervals. The RRc abundances are in good agreement with those derived for the RRabmore » stars of Chadid et al. We used radial velocity (RV) measurements of metal lines and H α to construct variations of velocity with phase, and center-of-mass velocities. We used these to construct RV templates for use in low- to medium-resolution RV surveys of RRc stars. Additionally, we calculated primary accelerations, radius variations, and metal and H α velocity amplitudes, which we display as regressions against primary acceleration. We employ these results to compare the atmosphere structures of metal-poor RRc stars with their RRab counterparts. Finally, we use the RV data for our Blazhko stars and the Blazhko periods of Szczygieł and Fabrycky to falsify the Blazhko oblique rotator hypothesis.« less

Cassini UVIS Auroral Observations in 2016 and 2017

NASA Astrophysics Data System (ADS)

Pryor, Wayne R.; Esposito, Larry W.; Jouchoux, Alain; Radioti, Aikaterini; Grodent, Denis; Gustin, Jacques; Gerard, Jean-Claude; Lamy, Laurent; Badman, Sarah; Dyudina, Ulyana A.; Cassini UVIS Team, Cassini VIMS Team, Cassini ISS Team, HST Saturn Auroral Team

2017-10-01

In 2016 and 2017, the Cassini Saturn orbiter executed a final series of high-inclination, low-periapsis orbits ideal for studies of Saturn's polar regions. The Cassini Ultraviolet Imaging Spectrograph (UVIS) obtained an extensive set of auroral images, some at the highest spatial resolution obtained during Cassini's long orbital mission (2004-2017). In some cases, two or three spacecraft slews at right angles to the long slit of the spectrograph were required to cover the entire auroral region to form auroral images. We will present selected images from this set showing narrow arcs of emission, more diffuse auroral emissions, multiple auroral arcs in a single image, discrete spots of emission, small scale vortices, large-scale spiral forms, and parallel linear features that appear to cross in places like twisted wires. Some shorter features are transverse to the main auroral arcs, like barbs on a wire. UVIS observations were in some cases simultaneous with auroral observations from the Cassini Imaging Science Subsystem (ISS) the Cassini Visual and Infrared Mapping Spectrometer (VIMS), and the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) that will also be presented.

Optical Alignment and Diffraction Analysis for AIRES: An Airborne Infrared Echelle Spectrometer

NASA Technical Reports Server (NTRS)

Haas, Michael R.; Fonda, Mark (Technical Monitor)

2002-01-01

The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed.

Unexpected effects of a trap in CCD echelle spectra of B-type stars

NASA Technical Reports Server (NTRS)

Morrison, Nancy D.; Zimba, Jason R.

1990-01-01

Because of the nature of echelle spectra, cosmetic defects such as traps may mimic real spectral features. An example from spectra taken at CTIO with a GEC CCD is presented, and it is shown how the affected pixels can be eliminated from the reduced spectrum, at a slight cost in signal-to-noise ratio.

GHRS Cycle 5 Echelle Wavelength Monitor

NASA Astrophysics Data System (ADS)

Soderblom, David

1995-07-01

This proposal defines the spectral lamp test for Echelle A. It is an internal test which makes measurements of the wavelength lamp SC2. It calibrates the carrousel function, Y deflections, resolving power, sensitivity, and scattered light. The wavelength calibration dispersion constants will be updated in the PODPS calibration data base. This proposal defines the spectral lamp test for Echelle B. It is an internal test which makes measurements of the wavelength lamp SC2. It calibrates the carrousel function, Y deflections, resolving power, sensitivity, and scattered light. The wavelength calibration dispersion constants will be updated in the PODPS calibration data base. It will be run every 4 months. The wavelengths may be out of range according to PEPSI or TRANS. Please ignore the errors.

Direct-current arc and alternating-current spark emission spectrographic field methods for the semiquantitative analysis of geologic materials

USGS Publications Warehouse

Grimes, D.J.; Marranzino, A.P.

1968-01-01

Two spectrographic methods are used in mobile field laboratories of the U. S. Geological Survey. In the direct-current arc method, the ground sample is mixed with graphite powder, packed into an electrode crater, and burned to completion. Thirty elements are determined. In the spark method, the sample, ground to pass a 150-mesh screen, is digested in hydrofluoric acid followed by evaporation to dryness and dissolution in aqua regia. The solution is fed into the spark gap by means of a rotating-disk electrode arrangement and is excited with an alternating-current spark discharge. Fourteen elements are determined. In both techniques, light is recorded on Spectrum Analysis No. 1, 35-millimeter film, and the spectra are compared visually with those of standard films.

VSOP: the variable star one-shot project. I. Project presentation and first data release

NASA Astrophysics Data System (ADS)

Dall, T. H.; Foellmi, C.; Pritchard, J.; Lo Curto, G.; Allende Prieto, C.; Bruntt, H.; Amado, P. J.; Arentoft, T.; Baes, M.; Depagne, E.; Fernandez, M.; Ivanov, V.; Koesterke, L.; Monaco, L.; O'Brien, K.; Sarro, L. M.; Saviane, I.; Scharwächter, J.; Schmidtobreick, L.; Schütz, O.; Seifahrt, A.; Selman, F.; Stefanon, M.; Sterzik, M.

2007-08-01

Context: About 500 new variable stars enter the General Catalogue of Variable Stars (GCVS) every year. Most of them however lack spectroscopic observations, which remains critical for a correct assignement of the variability type and for the understanding of the object. Aims: The Variable Star One-shot Project (VSOP) is aimed at (1) providing the variability type and spectral type of all unstudied variable stars, (2) process, publish, and make the data available as automatically as possible, and (3) generate serendipitous discoveries. This first paper describes the project itself, the acquisition of the data, the dataflow, the spectroscopic analysis and the on-line availability of the fully calibrated and reduced data. We also present the results on the 221 stars observed during the first semester of the project. Methods: We used the high-resolution echelle spectrographs HARPS and FEROS in the ESO La Silla Observatory (Chile) to survey known variable stars. Once reduced by the dedicated pipelines, the radial velocities are determined from cross correlation with synthetic template spectra, and the spectral types are determined by an automatic minimum distance matching to synthetic spectra, with traditional manual spectral typing cross-checks. The variability types are determined by manually evaluating the available light curves and the spectroscopy. In the future, a new automatic classifier, currently being developed by members of the VSOP team, based on these spectroscopic data and on the photometric classifier developed for the COROT and Gaia space missions, will be used. Results: We confirm or revise spectral types of 221 variable stars from the GCVS. We identify 26 previously unknown multiple systems, among them several visual binaries with spectroscopic binary individual components. We present new individual results for the multiple systems V349 Vel and BC Gru, for the composite spectrum star V4385 Sgr, for the T Tauri star V1045 Sco, and for DM Boo which we re-classify as a BY Draconis variable. The complete data release can be accessed via the VSOP web site. Based on data obtained at the La Silla Observatory, European Southern Observatory, under program ID 077.D-0085.

Spotting high-z molecular absorbers using neutral carbon. Results from a complete spectroscopic survey with the VLT

NASA Astrophysics Data System (ADS)

Noterdaeme, P.; Ledoux, C.; Zou, S.; Petitjean, P.; Srianand, R.; Balashev, S.; López, S.

2018-04-01

While molecular quasar absorption systems provide unique probes of the physical and chemical properties of the gas as well as original constraints on fundamental physics and cosmology, their detection remains challenging. Here we present the results from a complete survey for molecular gas in thirty-nine absorption systems selected solely upon the detection of neutral carbon lines in Sloan Digital Sky Survey (SDSS) spectra, without any prior knowledge of the atomic or molecular gas content. H2 is found in all twelve systems (including seven new detections) where the corresponding lines are covered by the instrument setups and measured to have logN(H2) ≳ 18, indicating a self-shielded regime. We also report seven CO detections (7/39) down to logN(CO) 13.5, including a new one, and put stringent constraints on N(CO) for the remaining 32 systems. N(CO) and N(C I) are found to be strongly correlated with N(CO)/N(C I) 1/10. This suggests that the C I-selected absorber population is probing gas deeper than the H I–H2 transition in which a substantial fraction of the total hydrogen in the cloud is in the form of H2. We conclude that targeting C I-bearing absorbers is a very efficient way to find high-metallicity molecular absorbers. However, probing the molecular content in lower-metallicity regimes as well as high-column-density neutral gas remains to be undertaken to unravel the processes of gas conversion in normal high-z galaxies. Based on observations and archival data from the European Southern Observatory (ESO) prog. IDs 060.A-9024, 072.A-0346, 278.A-5062, 080.A-0482, 080.A-0795, 081.A-0242, 081.A-0334, 082.A-0544, 082.A-0569, 083.A-0454, 084.A-0699, 086.A-0074 and 086.A-0643 using the Ultraviolet and Visual Echelle Spectrograph (UVES) and X-shooter at the Very Large Telescope (VLT), on Cerro Paranal, Chile.

CO-dark molecular gas at high redshift: very large H2 content and high pressure in a low-metallicity damped Lyman alpha system

NASA Astrophysics Data System (ADS)

Balashev, S. A.; Noterdaeme, P.; Rahmani, H.; Klimenko, V. V.; Ledoux, C.; Petitjean, P.; Srianand, R.; Ivanchik, A. V.; Varshalovich, D. A.

2017-09-01

We present a detailed analysis of an H2-rich, extremely strong intervening damped Ly α absorption system (DLA) at zabs = 2.786 towards the quasar J 0843+0221, observed with the Ultraviolet and Visual Echelle Spectrograph on the Very Large Telescope. The total column density of molecular (resp. atomic) hydrogen is log N(H2) = 21.21 ± 0.02 (resp. log N(H I) = 21.82 ± 0.11), making it to be the first case in quasar absorption line studies with H2 column density as high as what is seen in 13CO-selected clouds in the Milky Way. We find that this system has one of the lowest metallicity detected among H2-bearing DLAs, with [Zn/H] = -1.52^{+0.08}_{-0.10}. This can be the reason for the marked differences compared to systems with similar H2 column densities in the local Universe: (I) the kinetic temperature, T ˜ 120 K, derived from the J = 0, 1 H2 rotational levels is at least twice higher than expected; (II) there is little dust extinction with AV < 0.1; (III) no CO molecules are detected, putting a constraint on the XCO factor XCO > 2 × 1023 cm-2/(km s-1 K), in the very low metallicity gas. Low CO and high H2 contents indicate that this system represents 'CO-dark/faint' gas. We investigate the physical conditions in the H2-bearing gas using the fine-structure levels of C I, C II, Si II and the rotational levels of HD and H2. We find the number density to be about n ˜ 260-380 cm-3, implying a high thermal pressure of 3-5 × 104 cm-3 K. We further identify a trend of increasing pressure with increasing total hydrogen column density. This independently supports the suggestion that extremely strong DLAs (with log N(H) ˜22) probe high-z galaxies at low impact parameters.

Search with UVES and X-Shooter for signatures of the low-mass secondary in the post common-envelope binary AA Doradus

NASA Astrophysics Data System (ADS)

Hoyer, D.; Rauch, T.; Werner, K.; Hauschildt, P. H.; Kruk, J. W.

2015-06-01

Context. AA Dor is a close, totally eclipsing, post common-envelope binary with an sdOB-type primary star and an extremely low-mass secondary star, located close to the mass limit of stable central hydrogen burning. Within error limits, it may either be a brown dwarf or a late M-type dwarf. Aims: We aim to extract the secondary's contribution to the phase-dependent composite spectra. The spectrum and identified lines of the secondary decide on its nature. Methods: In January 2014, we measured the phase-dependent spectrum of AA Dor with X-Shooter over one complete orbital period. Since the secondary's rotation is presumable synchronized with the orbital period, its surface strictly divides into a day and night side. Therefore, we may obtain the spectrum of its cool side during its transit and of its hot, irradiated side close to its occultation. We developed the Virtual Observatory (VO) tool TLISA to search for weak lines of a faint companion in a binary system. We successfully applied it to the observations of AA Dor. Results: We identified 53 spectral lines of the secondary in the ultraviolet-blue, visual, and near-infrared X-Shooter spectra that are strongest close to its occultation. We identified 57 (20 additional) lines in available Ultraviolet and Visual Echelle Spectrograph (UVES) spectra from 2001. The lines are mostly from C ii-iii and O ii, typical for a low-mass star that is irradiated and heated by the primary. We verified the orbital period of P = 22 597.033201 ± 0.00007 s and determined the orbital velocity K_sec = 232.9+16.6-6.5 km s-1 of the secondary. The mass of the secondary is M_sec = 0.081+0.018-0.010 M_⊙ and, hence, it is not possible to reliably determine a brown dwarf or an M-type dwarf nature. Conclusions: Although we identified many emission lines of the secondary's irradiated surface, the resolution and signal-to-noise ratio of our UVES and X-Shooter spectra are not good enough to extract a good spectrum of the secondary's nonirradiated hemisphere. Based on observations collected at the European Southern Observatory, Chile, programs 066.D-1800 and 092.C-0692.Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer.Figures 2-5, 9, and Appendices are available in electronic form at http://www.aanda.org

A Python Script for Aligning the STIS Echelle Blaze Function

NASA Astrophysics Data System (ADS)

Baer, Malinda; Proffitt, Charles R.; Lockwood, Sean A.

2018-01-01

Accurate flux calibration for the STIS echelle modes is heavily dependent on the proper alignment of the blaze function for each spectral order. However, due to changes in the instrument alignment over time and between exposures, the blaze function can shift in wavelength. This may result in flux calibration inconsistencies of up to 10%. We present the stisblazefix Python module as a tool for STIS users to correct their echelle spectra. The stisblazefix module assumes that the error in the blaze alignment is a linear function of spectral order, and finds the set of shifts that minimizes the flux inconsistencies in the overlap between spectral orders. We discuss the uses and limitations of this tool, and show that its use can provide significant improvements to the default pipeline flux calibration for many observations.

A Newly Developed Fluorescence Model for C2H6 ν5 and Application to Cometary Spectra Acquired with NIRSPEC at Keck II

NASA Astrophysics Data System (ADS)

Radeva, Yana L.; Mumma, Michael J.; Villanueva, Geronimo L.; A'Hearn, Michael F.

2011-03-01

Accurate rotational temperatures are essential for extracting production rates for parent volatiles in comets. Two strong bands of ethane (ν7 at 2985.39 cm-1 and ν5 at 2895.67 cm-1) are seen in infrared cometary spectra, but the Q-branches of ν7 are not resolved by current instruments and cannot provide an accurate rotational temperature with current models. We developed a fluorescence model for the C2H6 ν5 band that can be used to derive a rotational temperature. We applied our C2H6 ν5 model to high-resolution infrared spectra of the comets C/2004 Q2 Machholz and C/2000 WM1 (LINEAR), acquired with the Near-infrared Echelle Spectrograph on the Keck II telescope. We demonstrate agreement among the rotational temperatures derived from C2H6 ν5 and other species, and between mixing ratios derived from C2H6 ν5 and C2H6 ν7. As a symmetric hydrocarbon, C2H6 is observed only in the infrared, and it is now the fifth molecule (along with H2O, HCN, CO, and H2CO) for which we can derive a reliable rotational temperature from cometary infrared spectra.

Potential Line Structure Variability in DIB Features Observed in Pathfinder tres Survey

NASA Astrophysics Data System (ADS)

Law, Charles; Milisavljevic, Dan; Crabtree, Kyle N.; Johansen, Sommer Lynn

2017-06-01

The Diffuse Interstellar Bands (DIBs) are hundreds of spectral lines observed in sightlines towards many stars in the optical and near-infrared. Although most of these transitions remain unassigned, four of them have recently been assigned to C_{60}^{+} and C_{70}^{+}. In earlier observations of the visible spectrum of the extragalactic supernova SN 2012ap, we observed changes in the equivalent widths of DIBs on the timescale of its light curve, which indicated that some DIB carriers might exist closer to massive stars then previously believed. Motivated by these findings, we undertook a pathfinder survey of 17 massive stars with the Tillinghast Reflector Echelle Spectrograph at Fred L. Whipple Observatory in search of temporal variability in DIBs. In 3 of the 17 stars, we found possible evidence for variation in line substructure of DIBs λ5797 and λ6614. In this talk, we will discuss our efforts to model λ5797 toward MT-59 using contour simulations based on previously published spectral models from higher resolution observations. Although the SNR of this spectrum was only 5-15, our preliminary results suggest that the variations in molecular spectra over time might arise from changes in carrier temperature. These early results demonstrate the need for higher SNR spectra taken at multiple epochs to further explore potential temporal variability. If successful, time-variation could provide additional evidence to assist in identifying DIB carriers.

The Kinematics of the Permitted C II λ6578 Line in a Large Sample of Planetary Nebulae

NASA Astrophysics Data System (ADS)

Richer, Michael G.; Suárez, Genaro; López, José Alberto; García Díaz, María Teresa

2017-03-01

We present spectroscopic observations of the C II λ6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir. We study the kinematics of the C II λ6578 permitted line with respect to other permitted and collisionally excited lines. Statistically, we find that the kinematics of the C II λ6578 line are not those expected if this line arises from the recombination of C2+ ions or the fluorescence of C+ ions in ionization equilibrium in a chemically homogeneous nebular plasma, but instead its kinematics are those appropriate for a volume more internal than expected. The planetary nebulae in this sample have well-defined morphology and are restricted to a limited range in Hα line widths (no large values) compared to their counterparts in the Milky Way bulge; both these features could be interpreted as the result of young nebular shells, an inference that is also supported by nebular modeling. Concerning the long-standing discrepancy between chemical abundances inferred from permitted and collisionally excited emission lines in photoionized nebulae, our results imply that multiple plasma components occur commonly in planetary nebulae.

The Variability of Atmospheric Deuterium Brightness at Mars: Evidence for Seasonal Dependence

NASA Astrophysics Data System (ADS)

Mayyasi, Majd; Clarke, John; Bhattacharyya, Dolon; Deighan, Justin; Jain, Sonal; Chaffin, Michael; Thiemann, Edward; Schneider, Nick; Jakosky, Bruce

2017-10-01

The enhanced ratio of deuterium to hydrogen on Mars has been widely interpreted as indicating the loss of a large column of water into space, and the hydrogen content of the upper atmosphere is now known to be highly variable. The variation in the properties of both deuterium and hydrogen in the upper atmosphere of Mars is indicative of the dynamical processes that produce these species and propagate them to altitudes where they can escape the planet. Understanding the seasonal variability of D is key to understanding the variability of the escape rate of water from Mars. Data from a 15 month observing campaign, made by the Mars Atmosphere and Volatile Evolution Imaging Ultraviolet Spectrograph high-resolution echelle channel, are used to determine the brightness of deuterium as observed at the limb of Mars. The D emission is highly variable, with a peak in brightness just after southern summer solstice. The trends of D brightness are examined against extrinsic as well as intrinsic sources. It is found that the fluctuations in deuterium brightness in the upper atmosphere of Mars (up to 400 km), corrected for periodic solar variations, vary on timescales that are similar to those of water vapor fluctuations lower in the atmosphere (20-80 km). The observed variability in deuterium may be attributed to seasonal factors such as regional dust storm activity and subsequent circulation lower in the atmosphere.

Fundamental Parameters of Nearby Young Stars

NASA Astrophysics Data System (ADS)

McCarthy, Kyle; Wilhelm, R. J.

2013-06-01

We present high resolution (R ~ 60,000) spectroscopic data of F and G members of the nearby, young associations AB Doradus and β Pictoris obtained with the Cross-Dispersed Echelle Spectrograph on the 2.7 meter telescope at the McDonald Observatory. Effective temperatures, log(g), [Fe/H], and microturbulent velocities are first estimated using the TGVIT code, then finely tuned using MOOG. Equivalent width (EW) measurements were made using TAME alongside a self-produced IDL routine to constrain EW accuracy and improve computed fundamental parameters. MOOG is also used to derive the chemical abundance of several elements including Mn which is known to be over abundant in planet hosting stars. Vsin(i) are also computed using a χ2 analysis of our observed data to Atlas9 model atmospheres passed through the SPECTRUM spectral synthesis code on lines which do not depend strongly on surface gravity. Due to the limited number of Fe II lines which govern the surface gravity fit in both TGVIT and MOOG, we implement another χ2 analysis of strongly log(g) dependent lines to ensure the values are correct. Coupling the surface gravities and temperatures derived in this study with the luminosities found in the Tycho-2 catalog, we estimate masses for each star and compare these masses to several evolutionary models to begin the process of constraining pre-main sequence evolutionary models.

Gas Distributions in Comet ISON’s Coma: Concurrent Integral-Field Spectroscopy and Narrow-band Imaging.

NASA Astrophysics Data System (ADS)

Schmidt, Carl; Johnson, Robert E.; Baumgardner, Jeffrey; Mendillo, Michael

2014-11-01

At a solar distance of 0.44 AU, Oort cloud comet C/2012 S1 (ISON) exhibited an outburst phase that was observed by small telescopes at the McDonald Observatory. In conjunction with narrow-band (14Å) imaging over a wide-field, an image-slicer spectrograph ( 20,000) simultaneously measured the spatial distribution of ISON’s coma over a 1.6 x 2.7 arcminute field made up of 246 individual spectra. More than fifty emission lines from C2, NH2, CO, H2O+ and Na were observed within a single Echelle order spanning 5868Å to 5930Å. Spatial reconstructions of these species reveal that ISON’s coma was quite elongated several thousand km along the axis perpendicular to its motion. The ion tail appeared distinctly broader than the neutral Na tail, providing strong evidence that Na in the coma did not originate by dissociative recombination of a sodium bearing molecular ion. Production rates increased from 1.6 ± 0.3 x 1023 to 5.8 ± 1 x 1023 Na atoms/s within 24 hours, outgassing much less than comparable comets relative to ISON’s water production. The anti-sunward Na tail was imaged >106 km from the nucleus. Its distribution indicates origins both near the nucleus and in the dust tail, with the ratio of these Na sources varying on hourly timescales due to outburst activity.

Alignment of sensor arrays in optical instruments using a geometric approach.

PubMed

Sawyer, Travis W

2018-02-01

Alignment of sensor arrays in optical instruments is critical to maximize the instrument's performance. While many commercial systems use standardized mounting threads for alignment, custom systems require specialized equipment and alignment procedures. These alignment procedures can be time-consuming, dependent on operator experience, and have low repeatability. Furthermore, each alignment solution must be considered on a case-by-case basis, leading to additional time and resource cost. Here I present a method to align a sensor array using geometric analysis. By imaging a grid pattern of dots, I show that it is possible to calculate the misalignment for a sensor in five degrees of freedom simultaneously. I first test the approach by simulating different cases of misalignment using Zemax before applying the method to experimentally acquired data of sensor misalignment for an echelle spectrograph. The results show that the algorithm effectively quantifies misalignment in five degrees of freedom for an F/5 imaging system, accurate to within ±0.87  deg in rotation and ±0.86  μm in translation. Furthermore, the results suggest that the method can also be applied to non-imaging systems with a small penalty to precision. This general approach can potentially improve the alignment of sensor arrays in custom instruments by offering an accurate, quantitative approach to calculating misalignment in five degrees of freedom simultaneously.

Stringent upper limit of CH4 on Mars based on SOFIA/EXES observations

NASA Astrophysics Data System (ADS)

Aoki, S.; Richter, M. J.; DeWitt, C.; Boogert, A.; Encrenaz, T.; Sagawa, H.; Nakagawa, H.; Vandaele, A. C.; Giuranna, M.; Greathouse, T. K.; Fouchet, T.; Geminale, A.; Sindoni, G.; McKelvey, M.; Case, M.; Kasaba, Y.

2018-03-01

Discovery of CH4 in the Martian atmosphere has led to much discussion since it could be a signature of biological and/or geological activities on Mars. However, the presence of CH4 and its temporal and spatial variations are still under discussion because of the large uncertainties embedded in the previous observations. We performed sensitive measurements of Martian CH4 by using the Echelon-Cross-Echelle Spectrograph (EXES) onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA) on 16 March 2016, which corresponds to summer (Ls = 123.2∘) in the northern hemisphere on Mars. The high altitude of SOFIA ( 13.7 km) enables us to significantly reduce the effects of terrestrial atmosphere. Thanks to this, SOFIA/EXES improves our chances of detecting Martian CH4 lines because it reduces the impact of telluric CH4 on Martian CH4, and allows us to use CH4 lines in the 7.5 μm band which has less contamination. However, our results show no unambiguous detection of Martian CH4. The Martian disk was spatially resolved into 3 × 3 areas, and the upper limits on the CH4 volume mixing ratio range from 1 to 9 ppb across the Martian atmosphere, which is significantly less than detections in several other studies. These results emphasize that release of CH4 on Mars is sporadic and/or localized if the process is present.

High Resolution Optical Spectroscopy of an Intriguing High-Latitude B-Type Star HD119608

NASA Astrophysics Data System (ADS)

Şahin, T.

2018-01-01

We present an LTE analysis of high resolution echelle optical spectra obtained with the 3.9-m Anglo-Australian Telescope (AAT) and the UCLES spectrograph for a B1Ib high galactic latitude supergiant HD119608. A fresh determination of the atmospheric parameters using line-blanketed LTE model atmospheres and spectral synthesis provided T eff = 23 300 ± 1000 K, log g = 3.0 ± 0.3, and the microturbulent velocity ξ = 6.0 ± 1.0 kms-1 and [Fe/H] = 0.16. The rotational velocity of the star was derived fromC, O, N, Al, and Fe lines as v sin i = 55.8 ± 1.3 kms-1. Elemental abundances were obtained for 10 different species. He, Al, and P abundances of the star were determined for the first time. In the spectra, hot post-AGB status as well as the Pop I characteristics of the star were examined. The approximately solar carbon and oxygen abundances, along with mild excess in helium and nitrogen abundances do not stipulate a CNO processed surface composition, hence a hot post-AGB status. The LTE abundances analysis also indicates solar sulphur and moderately enriched magnesium abundances. The average abundances of B dwarfs of well studied OB associations and Population I stars show a striking resemblance to abundances obtained for HD119608 in this study. This may imply a runaway status for the star.

VizieR Online Data Catalog: Spectroscopic and photometric properties of Tombaugh 1 (Sales+, 2016)

NASA Astrophysics Data System (ADS)

Sales Silva, J. V.; Carraro, G.; Anthony-Twarog, B. J.; Moni Bidin, C.; Costa, E.; Twarog, B. A.

2018-03-01

Photometry for Tombaugh 1 was secured in 2010 December during a five-night run using the Cerro Tololo Inter-American Observatory 1.0 m telescope operated by the SMARTS consortium (http://www.astro.yale.edu/smarts). The telescope is equipped with an STA 4064x4064 CCD camera (http://www.astronomy.ohio-state.edu/Y4KCam/detector) with 15 μm pixels, yielding a scale of 0.289"/pixel and a field of view (FOV) of 20'x20' at the Cassegrain focus of the telescope. Over the night of 2010 January 5, we observed 10 potential cluster stars (nine clump stars and one Cepheid; see Section 4.1) with the Inamori-Magellan Areal Camera & Spectrograph (IMACS; Dressler et al. 2006SPIE.6269E..0FD) attached to the Magellan telescope (6.5 m) located at Las Campanas, Chile. The spectra were obtained using the Multi-Object Echelle (MOE) mode with two exposures, one of 900 s and the other of 1200 s. Our spectra have a resolution of R~20000, while the spectral coverage depends on the location of the star on the multislit mask, but it generally goes from 4200 to 9100 Å. The detector consists of a mosaic with eight CCDs with gaps of about 0.93 mm between the CCDs, causing small gaps in stellar spectra. (7 data files).

The Fourth Flight of CHESS: Analysis of Interstellar H2 on the γ Ara Sightline

NASA Astrophysics Data System (ADS)

Kruczek, Nick E.; France, Kevin; Nell, Nicholas; Fleming, Brian

2018-06-01

In this talk, we describe the scientific motivation and technical development of the Colorado High-resolution Echelle Stellar Spectrograph (CHESS) sounding rocket, focusing on the preliminary science results for the fourth launch of the payload (CHESS-4). CHESS is a far ultraviolet rocket-borne instrument designed to study the atomic-to-molecular transitions within translucent cloud regions in the interstellar medium. CHESS-4 launched on 13 April 2018 aboard NASA/CU sounding rocket mission 36.333 UG. The target for this flight was γ Ara, a B1I star that is known to display a variable and equatorially enhanced stellar wind. We present flight results of interstellar molecular hydrogen excitation, including initial measurements of the column density and temperature, on the sightline. These results are compared to previous values that were calculated using the damping wings of low-J H2 absorption features in Copernicus spectra. We also present analogous flight data for the sightline toward β Sco, finding that the derived column density of the J” = 1 rotational level differs by a factor of ~2 when compared to the previous observations. We discuss the discrepancies between the two measurements and show that the source of the difference is likely due to the opacity of higher rotational levels contributing to the J” = 1 absorption wing, increasing the inferred column density in the previous work.

The Remote Observatories of the Southeastern Association for Research in Astronomy (SARA)

NASA Astrophysics Data System (ADS)

Keel, William C.; Oswalt, Terry; Mack, Peter; Henson, Gary; Hillwig, Todd; Batcheldor, Daniel; Berrington, Robert; De Pree, Chris; Hartmann, Dieter; Leake, Martha; Licandro, Javier; Murphy, Brian; Webb, James; Wood, Matt A.

2017-01-01

We describe the remote facilities operated by the Southeastern Association for Research in Astronomy (SARA) , a consortium of colleges and universities in the US partnered with Lowell Observatory, the Chilean National Telescope Allocation Committee, and the Instituto de Astrofísica de Canarias. SARA observatories comprise a 0.96 m telescope at Kitt Peak, Arizona; one of 0.6 m aperture on Cerro Tololo, Chile; and the 1 m Jacobus Kapteyn Telescope at the Roque de los Muchachos, La Palma, Spain. All are operated using standard VNC or Radmin protocols communicating with on-site PCs. Remote operation offers considerable flexibility in scheduling, allowing long-term observational cadences difficult to achieve with classical observing at remote facilities, as well as obvious travel savings. Multiple observers at different locations can share a telescope for training, educational use, or collaborative research programs. Each telescope has a CCD system for optical imaging, using thermoelectric cooling to avoid the need for frequent local service, and a second CCD for offset guiding. The Arizona and Chile telescopes also have fiber-fed echelle spectrographs. Switching between imaging and spectroscopy is very rapid, so a night can easily accommodate mixed observing modes. We present some sample observational programs. For the benefit of other groups organizing similar consortia, we describe the operating structure and principles of SARA, as well as some lessons learned from almost 20 years of remote operations.

Spectroscopic Observations of Nearby Low Mass Stars

NASA Astrophysics Data System (ADS)

Vican, Laura; Zuckerman, B. M.; Rodriguez, D.

2014-01-01

Young low-mass stars are known to be bright in X-ray and UV due to a high level of magnetic activity. By cross-correlating the GALEX Catalog with the WISE and 2MASS Point Source Catalogs, we have identified more than 2,000 stars whose UV excesses suggest ages in the 10-100 Myr range. We used the Shane 3-m telescope at Lick Observatory on Mount Hamilton, California to observe some of these 2,000 stars spectroscopically. We measured the equivalent width of lithium at 6708 A absorption and H-alpha emission lines. Out of a total of 122 stars observed with the Kast grating spectrometer, we find that roughly 10% have strong lithium absorption features. The high percentage of stars with lithium present is further evidence of the importance of UV emission as a youth indicator for low-mass stars. In addition, we used high-resolution spectra obtained with the Hamilton echelle spectrograph to determine radial velocities for several UV-bright stars. These radial velocities will be useful for the calculation of Galactic UVW space velocities for determination of possible moving group membership. This work is supported by NASA Astrophysics Data Analysis Program award NNX12AH37G to RIT and UCLA and Chilean FONDECYT grant 3130520 to Universidad de Chile. This submission presents work for the GALNYSS project and should be linked to abstracts submitted by David Rodriguez, Laura Vican, and Joel Kastner.

A Differential Chemical Abundance Scale for the Globular Cluster M5

NASA Astrophysics Data System (ADS)

Koch, Andreas; McWilliam, Andrew

2010-06-01

We present LTE chemical abundances for five red giants and one AGB star in the Galactic globular cluster (GC) M5 based on high-resolution spectroscopy using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan 6.5 m Clay telescope. Our results are based on a line-by-line differential abundance analysis relative to the well-studied red giant Arcturus. The stars in our sample that overlap with existing studies in the literature are consistent with published values for [Fe/H] and agree to within typically 0.04 dex for the α-elements. Most deviations can be assigned to varying analysis techniques in the literature. This strengthens our newly established differential GC abundance scale and advocates future use of this method. In particular, we confirm a mean [Fe I/H] of -1.33 ± 0.03 (stat.) ±0.03 (sys.) dex and also reproduce M5's enhancement in the α-elements (O, Mg, Si, Ca, Ti) at +0.4 dex, rendering M5 a typical representative of the Galactic halo. Over-ionization of Fe I in the atmospheres of these stars by non-LTE effects is found to be less than 0.07 dex. Five of our six stars show O-Na-Al-Mg abundance patterns consistent with pollution by proton-capture nucleosynthesis products. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Mapping the Heiles Supershell GSH 90-28-17

NASA Astrophysics Data System (ADS)

Montgomery, Sharon Lynn; Beckey, Jacob Lucas; Welsh, Barry; Kuehne, John W.

2017-01-01

Large-diameter shells of neutral gas called superbubbles were first detected by the 21-cm radio surveys of Heiles (1979,1984) and are likely formed by stellar winds and supernova explosions. Some of these interstellar voids (including GSH 90-28-17) span more than 10 degrees of the sky. However, only a few studies have been able to identify the power source of a particular Heiles shell. The problem is that HI 21cm emission can arise at all distances along a given sight-line, so while we many know the speed at which neutral gas is moving, we do not know the distance of this gas. Indeed, a given line of sight may penetrate multiple shell walls making the interpretation of the radio data very challenging.Here we report on an absorption study of the interstellar absorption lines of NaI, CaII, CaI, CH and CH+ detected towards nine stellar continuum sources with sight-line distances increasing from 90 pc to >1kpc in the direction of the supershell GSH 90-28-17. Our observations, recorded with the Sandiford echelle spectrograph on the 2.1m telescope at the McDonald Observatory (Texas) in August 2016, reveal gas components with velocities between -10 and -50 km/s orginating from distances >400 pc that we can associate with the expansion of the GSH 90-28-17 shell.

Heavy Element Abundances in Planetary Nebulae from Deep Optical Echelle Spectroscopy

NASA Astrophysics Data System (ADS)

Mashburn, Amanda; Sterling, Nicholas C.; Dinerstein, Harriet L.; Garofali, Kristen; Jensema, Rachael; Turbyfill, Amanda; Wieser, Hannah-Marie N.; Reed, Evan C.; Redfield, Seth

2016-01-01

We present the abundances of neutron(n)-capture elements (atomic number Z > 30) and iron determined from deep optical echelle spectroscopy of 14 Galactic planetary nebulae (PNe). The spectra were obtained with the 2D-coudé spectrograph on the 2.7-m Harlan J. Smith telescope at McDonald Observatory. The abundances of n-capture elements can be enhanced in PNe due to slow n-capture nucleosynthesis in the progenitor asymptotic giant branch (AGB) stars. The high spectral resolution of these data (R = 36,700) allow most n-capture element emission lines to be resolved from other nebular and telluric features. We detect Kr in all of the observed PNe (with multiple ions detected in several objects), while Br, Rb, and Xe were each detected in 4--5 objects. Using the new Kr ionization correction factors (ICFs) of Sterling et al. (2015, ApJS, 218, 25), we find [Kr/O] abundances ranging from 0.05 to 1.1 dex. We utilize approximate ICFs for the other n-capture elements, and find slightly lower enrichments for Br and Rb (-0.1 to 0.7 dex), while Xe is enhanced relative to solar by factors of two to 30. The [Xe/Kr] ratios range from -0.3 to 1.4 dex, indicating a significant range in neutron exposures in PN progenitor stars. Interestingly, the largest [Xe/Kr] ratio is found in the thick-disk PN NGC 6644, which has a lower metallicity than the other observed PNe. We detect iron emission lines in all but one target. Fe can be depleted into dust grains in ionized nebulae, and its abundance thus provides key information regarding dust-to-gas ratios and grain destruction processes. We find that [Fe/O] ranges from -1.3 to -0.7 dex in the observed PNe, a smaller spread of depletion factors than found in recent studies (Delgado-Inglada & Rodriguez 2014, ApJ, 784, 173) though this may be due in part to our smaller sample. These data are part of a larger study of heavy elements in PNe, which will provide more accurate determinations of n-capture element abundances than previous estimates in several PNe, thereby providing key new constraints to models of AGB nucleosynthesis and Galactic chemical evolution. This work was supported by NSF awards AST-0708245 and AST-901432.

EarthFinder: A Precise Radial Velocity Survey Probe Mission of our Nearest Stellar Neighbors for Earth-Mass Habitable Zone Analogs Using High-Resolution UV-Vis-NIR Echelle Spectroscopy on a Space Platform

NASA Astrophysics Data System (ADS)

Plavchan, Peter; EarthFinder Team

2018-01-01

We are investigating the science case for a 1.0-1.4 meter space telescope to survey the closest, brightest FGKM main sequence stars to search for Habitable Zone (HZ) Earth analogs using the precise radial velocity (PRV) technique at a precision of 1-10 cm/s. Our baseline instrument concept uses two diffraction-limited spectrographs operating in the 0.4-1.0 microns and 1.0-2.4 microns spectral regions each with a spectral resolution of R=150,000~200,000, with the possibility of a third UV arm. Because the instrument utilizes a diffraction-limited input beam, the spectrograph would be extremely compact, less than 50 cm on a side, and illumination can be stabilized with the coupling of starlight into single mode fibers. With two octaves of wavelength coverage and a cadence unimpeded by any diurnal, seasonal, and atmospheric effects, EarthFinder will offer a unique platform for recovering stellar activity signals from starspots, plages, granulation, etc. to detect exoplanets at velocity semi-amplitudes currently not obtainable from the ground. Variable telluric absorption and emission lines may potentially preclude achieving PRV measurements at or below 10 cm/s in the visible and <50 cm/s in the near-infrared from the ground. Placed in an Earth-trailing (e.g. Spitzer, Kepler) or Lagrange orbit, the space-based cadence of observations of a star can be year-round at the ecliptic poles, with two ~100-day "seasons" every 6 months in the ecliptic plane. This will provide a distinct advantage compared to an annual ~3-6 month observing season from the ground for mitigating stellar activity and detecting the orbital periods of HZ Earth-mass analogs (e.g. ~6-months to ~2 years). Finally, we are compiling a list of ancillary science cases for the observatory, ranging from asteroseismology to the direct measurement of the expansion of the Universe.

New high spectral resolution spectrograph and mid-IR camera for the NASA Infrared Telescope Facility

NASA Astrophysics Data System (ADS)

Tokunaga, Alan T.; Bus, Schelte J.; Connelley, Michael; Rayner, John

2016-10-01

The NASA Infrared Telescope Facility (IRTF) is a 3.0 m infrared telescope located at an altitude of 4.2 km near the summit of Mauna Kea on the island of Hawaii. The IRTF was established by NASA to support planetary science missions. We show new observational capabilities resulting from the completion of iSHELL, a 1-5 μm echelle spectrograph with resolving power of 70,000 using a 0.375 arcsec slit. This instrument will be commissioned starting in August 2016. The spectral grasp of iSHELL is enormous due to the cross-dispersed design and use of a 2Kx2K HgCdTe array. Raw fits files will be publicly archived, allowing for more effective use of the large amount of spectral data that will be collected. The preliminary observing manual for iSHELL, containing the instrument description, observing procedures and estimates of sensitivity can be downloaded at http://irtfweb.ifa.hawaii.edu/~ishell/iSHELL_observing_manual.pdf. This manual and instrument description papers can be downloaded at http://bit.ly/28NFiMj. We are also working to restore to service our 8-25 μm camera, MIRSI. It will be upgraded with a closed cycle cooler that will eliminate the need for liquid helium and allow continuous use of MIRSI on the telescope. This will enable a wider range of Solar System studies at mid-IR wavelengths, with particular focus on thermal observations of NEOs. The MIRSI upgrade includes plans to integrate a visible CCD camera that will provide simultaneous imaging and guiding capabilities. This visible imager will utilize similar hardware and software as the MORIS system on SpeX. The MIRSI upgrade is being done in collaboration with David Trilling (NAU) and Joseph Hora (CfA). For further information on the IRTF and its instruments including visitor instruments, see: http:// irtfweb.ifa.hawaii.edu/. We gratefully acknowledge the support of NASA contract NNH14CK55B, NASA Science Mission Directorate, and NASA grant NNX15AF81G (Trilling, Hora) for the upgrade of MIRSI.

Kinematic and chemical study of planetary nebulae and H II regions in NGC 3109

NASA Astrophysics Data System (ADS)

Flores-Durán, S. N.; Peña, M.; Ruiz, M. T.

2017-05-01

Aims: We present high-resolution spectroscopy of a number of planetary nebulae (PNe) and H II regions distributed along the dwarf irregular galaxy NGC 3109 and compare their kinematical behavior with that of H I data. We aim to determine if there is a kinematical connection among these objects. We also aim to determine the chemical composition of some PNe and H II regions in this galaxy and discuss it in comparison with stellar evolution models. Methods: Data for eight PNe and one H II region were obtained with the high-resolution spectrograph Magellan Inamori Kyocera Echelle (MIKE) at Las Campanas Observatory, Chile. Data for three PNe, six compact H II regions, and nine knots or clumps in extended H II regions were obtained with the high-resolution spectrograph Manchester Echelle Spectrometer (MES) attached to the 2.1m telescope at the Observatorio Astronómico Nacional, SPM, B.C., Mexico. An additional object was obtained from The SPM Catalogue of Extragalactic Planetary Nebulae. Thus, in total we have high-quality data for nine of the 20 PNe detected in this galaxy, and many H II regions. In the wavelength calibrated spectra, the heliocentric radial velocities were measured with a precision better than 7.8 km s-1. Data for blue supergiant stars were collected from the literature to be included in the analysis. The heliocentric radial velocities of the different objects were compared to the velocities of the H I disk at the same position. Physical conditions and ionic abundances of PNe and H II regions were obtained from the emission lines, and we used recent ionization correction factors to derive the total chemical abundances. Results: From the analysis of radial velocities we found that H II regions in NGC 3109 share the kinematics of the H I disk at the same projected position with very low dispersion in velocities. Blue supergiant stars and PNe rotate in the same direction as the H I disk but these objects have much larger dispersion; this larger dispersion is possibly because these objects belong to a different population that is located in the central stellar bar reported for this galaxy. From the chemical abundance determinations we demonstrate that PNe are enriched in O and Ne. The average O abundance in H II regions is 12 + log O/H = 7.74 ± 0.09 and PNe show significantly higher oxygen abundance by 0.43 dex in average. Ne abundance are about three times larger in PNe than in H II regions. This is a very important result showing that because of the low metallicity in the galaxy, O and Ne in PNe have been enriched by their progenitors in nucleosynthesis processes and brought to the surface during third dredge-up events. Our PN abundances are better reproduced by some nonstandard stellar evolution models for a metallicity of Z = 0.001, similar to the metallicity of H II regions. Abundances in H II regions show no metallicity gradient in this galaxy. We discuss a possible connection between the kinematics and chemistry. Based on data obtained at Las Campanas Observatory, Carnegie Institution, Chile.Based on data collected at the Observatorio Astronómico Nacional, SPM, B.C., Mexico.

Total reduction of distorted echelle spectrograms - An automatic procedure. [for computer controlled microdensitometer

NASA Technical Reports Server (NTRS)

Peterson, R. C.; Title, A. M.

1975-01-01

A total reduction procedure, notable for its use of a computer-controlled microdensitometer for semi-automatically tracing curved spectra, is applied to distorted high-dispersion echelle spectra recorded by an image tube. Microdensitometer specifications are presented and the FORTRAN, TRACEN and SPOTS programs are outlined. The intensity spectrum of the photographic or electrographic plate is plotted on a graphic display. The time requirements are discussed in detail.

Emission spectrographic determination of volatile trace elements in geologic materials by a carrier distillation technique

USGS Publications Warehouse

Barton, H.N.

1986-01-01

Trace levels of chalcophile elements that form volatile sulfide minerals are determined in stream sediments and in the nonmagnetic fraction of a heavy-mineral concentrate of stream sediments by a carrier distillation emission spectrographic method. Photographically recorded spectra of samples are visually compared with those of synthetic standards for the two sample types. Rock and soil samples may also be analyzed by comparison with the stream-sediment standards. A gallium oxide spectrochemical carrier/buffer enhances the early emission of the volatile elements. Detection limits in parts per million attained are: Sb 5, As 20, Bi 0.1, Cd 1, Cu 1, Pb 2, Ag 0.1, Zn 2, and Sn 0.1. A comparison with other methods of analysis, total-burn emission and atomic absorption spectroscopy, shows good correlation for standard reference for materials and samples from a variety of geologic terranes. ?? 1986.

Establishment and correction of an Echelle cross-prism spectrogram reduction model

NASA Astrophysics Data System (ADS)

Zhang, Rui; Bayanheshig; Li, Xiaotian; Cui, Jicheng

2017-11-01

The accuracy of an echelle cross-prism spectrometer depends on the matching degree between the spectrum reduction model and the actual state of the spectrometer. However, the error of adjustment can change the actual state of the spectrometer and result in a reduction model that does not match. This produces an inaccurate wavelength calibration. Therefore, the calibration of a spectrogram reduction model is important for the analysis of any echelle cross-prism spectrometer. In this study, the spectrogram reduction model of an echelle cross-prism spectrometer was established. The image position laws of a spectrometer that varies with the system parameters were simulated to the influence of the changes in prism refractive index, focal length and so on, on the calculation results. The model was divided into different wavebands. The iterative method, least squares principle and element lamps with known characteristic wavelength were used to calibrate the spectral model in different wavebands to obtain the actual values of the system parameters. After correction, the deviation of actual x- and y-coordinates and the coordinates calculated by the model are less than one pixel. The model corrected by this method thus reflects the system parameters in the current spectrometer state and can assist in accurate wavelength extraction. The instrument installation and adjustment would be guided in model-repeated correction, reducing difficulty of equipment, respectively.

VizieR Online Data Catalog: NIR spectroscopy of new L and T dwarf candidates (Kellogg+, 2017)

NASA Astrophysics Data System (ADS)

Kellogg, K.; Metchev, S.; Miles-Paez, P. A.; Tannock, M. E.

2018-02-01

We implemented a photometric search for peculiar L and T dwarfs using combined optical (SDSS), near-infrared (2MASS) and mid-infrared (WISE) fluxes. In Paper I (Kellogg et al. 2015AJ....150..182K), we reported a sample of 314 objects that passed all of our selection criteria and visual verification. After refining our visual verification, our total candidate L and T dwarf list was cut to 156 objects including 104 new candidates. We obtained near-infrared spectroscopic observations of the remaining 104 objects in our survey (66 peculiarly red, 13 candidate binary, and 25 general ultra-cool dwarf candidates) using the SpeX instrument on the NASA Infrared Telescope Facility (IRTF) and the Gemini Near-Infrared Spectrograph (GNIRS) instrument on the Gemini North telescope. We obtained the majority of our follow-up observations (91 of 104) with the SpeX spectrograph on the IRTF in prism mode (0.75-2.5μm; R~75-150), between 2014 October and 2016 April. The observing sequences and instrument settings were the same as those in Paper I (Kellogg et al. 2015AJ....150..182K). Table1 gives observation epochs and SpeX instrument settings for each science target. We followed-up the remaining 13 objects in our candidate list using the Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North (0.9-2.5μm). We observed these objects in queue mode between 2015 October and 2017 May. We took the observations in cross-dispersed mode with the short-blue camera with 32l/mm grating and a 1.0''*7.0'' slit, resulting in a resolution of R~500. We used a standard A-B-B-A nodding sequence along the slit to record object and sky spectra. Individual exposure times were 120s per pointing. Table2 gives Gemini/GNIRS observation epochs for each science target. (4 data files).

TRES survey of variable diffuse interstellar bands

NASA Astrophysics Data System (ADS)

Law, Charles J.; Milisavljevic, Dan; Crabtree, Kyle N.; Johansen, Sommer L.; Patnaude, Daniel J.; Margutti, Raffaella; Parrent, Jerod T.; Drout, Maria R.; Sanders, Nathan E.; Kirshner, Robert P.; Latham, David W.

2017-09-01

Diffuse interstellar bands (DIBs) are absorption features commonly observed in optical/near-infrared spectra of stars and thought to be associated with polyatomic molecules that comprise a significant reservoir of organic material in the Universe. However, the central wavelengths of almost all DIBs do not correspond with electronic transitions of known atomic or molecular species and the specific physical nature of their carriers remains inconclusive despite decades of observational, theoretical and experimental research. It is well established that DIB carriers are located in the interstellar medium, but the recent discovery of time-varying DIBs in the spectra of the extragalactic supernova SN 2012ap suggests that some may be created in massive star environments. Here, we report evidence of short time-scale (∼10-60 d) changes in DIB absorption line substructure towards 3 of 17 massive stars observed as part of a pathfinder survey of variable DIBs conducted with the 1.5-m Tillinghast telescope and Tillinghast Reflector Echelle Spectrograph (TRES) at Fred L. Whipple Observatory. The detections are made in high-resolution optical spectra (R ∼ 44 000) having signal-to-noise ratios of 5-15 around the 5797 and 6614 Å features, and are considered significant but requiring further investigation. We find that these changes are potentially consistent with interactions between stellar winds and DIB carriers in close proximity. Our findings motivate a larger survey to further characterize these variations and may establish a powerful new method for probing the poorly understood physical characteristics of DIB carriers.

TRES Survey of Variable Diffuse Interstellar Bands

NASA Astrophysics Data System (ADS)

Law, Charles; Milisavljevic, Dan; Crabtree, Kyle; Johansen, Sommer; Patnaude, Daniel

2017-01-01

Diffuse interstellar bands (DIBs) are absorption features commonly observed in optical/near-infrared spectra of stars and thought to be associated with polyatomic molecules that comprise a significant reservoir of organic material in the universe. However, because the central wavelengths of DIBs do not correspond with electronic transitions of known atomic or molecular species, the specific physical nature of their carriers remains inconclusive despite decades of observational, theoretical, and experimental research. It is well established that DIB carriers must be located in the interstellar medium, but the recent discovery of time-varying DIBs in the spectra of the extragalactic supernova SN 2012ap suggests that some may be created in massive star environments. We report evidence of short time-scale (˜1-60 days) variations in DIB absorption line substructure toward 3 of 17 massive stars observed as part of a pathfinder survey of variable DIBs. The detections are made in high-resolution optical spectra (R ˜ 44000) from the Tillinghast Reflection Echelle Spectrograph on the 1.5m Tillinghast telescope at the Smithsonian Astrophysical Observatory's Fred L. Whipple Observatory on Mt. Hopkins in Arizona. Our detections have signal-to-noise ratios of 5-15 around the features of interest, and are thus considered significant but requiring further investigation. We find that these changes are potentially consistent with interactions between stellar winds and DIB carriers in close proximity. Our findings motivate a larger survey to further characterize these variations and may establish a powerful new method for probing the poorly understood physical characteristics of DIB carriers.

THE CHEMICAL ABUNDANCES OF STARS IN THE HALO (CASH) PROJECT. II. A SAMPLE OF 14 EXTREMELY METAL-POOR STARS ,

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hollek, Julie K.; Sneden, Christopher; Shetrone, Matthew

2011-11-20

We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High Resolution Spectrograph snapshot spectra (R {approx}15, 000) and corresponding high-resolution (R {approx}35, 000) Magellan Inamori Kyocera Echelle spectra. The stars span a metallicity range from [Fe/H] from -2.9 to -3.9, including four new stars with [Fe/H] < -3.7. We find four stars to be carbon-enhanced metal-poor (CEMP) stars, confirming the trend of increasing [C/Fe] abundance ratios with decreasing metallicity. Two of these objects can bemore » classified as CEMP-no stars, adding to the growing number of these objects at [Fe/H]< - 3. We also find four neutron-capture-enhanced stars in the sample, one of which has [Eu/Fe] of 0.8 with clear r-process signatures. These pilot sample stars are the most metal-poor ([Fe/H] {approx}< -3.0) of the brightest stars included in CASH and are used to calibrate a newly developed, automated stellar parameter and abundance determination pipeline. This code will be used for the entire {approx}500 star CASH snapshot sample. We find that the pipeline results are statistically identical for snapshot spectra when compared to a traditional, manual analysis from a high-resolution spectrum.« less

Chemical Composition of Two Bright, Extremely Metal-poor Stars from the SDSS MARVELS Pre-survey

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Avrajit; Sivarani, Thirupathi; Susmitha, Antony; Beers, Timothy C.; Giridhar, Sunetra; Surya, Arun; Masseron, Thomas

2018-06-01

SDSS J082625.70+612515.10 (V = 11.4 [Fe/H] = ‑3.1) and SDSS J134144.60+474128.90 (V = 12.4 [Fe/H] = ‑3.2) were observed with the SDSS 2.5m telescope as part of the SDSS MARVELS spectroscopic pre-survey and identified as extremely metal-poor (EMP; [Fe/H] < ‑3.0) stars during the high-resolution follow-up using the Hanle Echelle Spectrograph (HESP) on the 2.0-m Himalayan Chandra Telescope. In this paper, the first science results using HESP, we present a detailed analysis of their chemical abundances. Both stars exhibit under-abundances in their neutron capture elements, while one of them (SDSS J134144.60+474128.90) is clearly enhanced in carbon. Lithium was also detected in this star at a level of about A(Li) = 1.95. The spectra were obtained over a span of 6–24 months, and indicate that both stars could be members of binary systems. We compare the elemental abundances derived for these two stars along with other carbon-enhanced metal-poor (CEMP) and EMP stars, in order to understand the nature of their parent supernovae. We find that CEMP-no stars and EMP-dwarfs show a very similar trend in their lithium abundances at various metallicities. We also find indications of CEMP-no stars having larger abundances of Cr and Co at given metallicities compared to EMP stars.

HAT-P-31b,c: A TRANSITING, ECCENTRIC, HOT JUPITER AND A LONG-PERIOD, MASSIVE THIRD BODY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kipping, D. M.; Hartman, J.; Bakos, G. A.

2011-09-15

We report the discovery of HAT-P-31b, a transiting exoplanet orbiting the V = 11.660 dwarf star GSC 2099-00908. HAT-P-31b is the first planet discovered with the Hungarian-made Automated Telescope (HAT) without any follow-up photometry, demonstrating the feasibility of a new mode of operation for the HATNet project. The 2.17 M{sub J} , 1.1 R{sub J} planet has a period of P{sub b} = 5.0054 days and maintains an unusually high eccentricity of e{sub b} = 0.2450 {+-} 0.0045, determined through Keck, FIbr-fed Echelle Spectrograph, and Subaru high-precision radial velocities (RVs). Detailed modeling of the RVs indicates an additional quadratic residualmore » trend in the data detected to very high confidence. We interpret this trend as a long-period outer companion, HAT-P-31c, of minimum mass 3.4 M{sub J} and period {>=}2.8 years. Since current RVs span less than half an orbital period, we are unable to determine the properties of HAT-P-31c to high confidence. However, dynamical simulations of two possible configurations show that orbital stability is to be expected. Further, if HAT-P-31c has non-zero eccentricity, our simulations show that the eccentricity of HAT-P-31b is actively driven by the presence of c, making HAT-P-31 a potentially intriguing dynamical laboratory.« less

The composition of the Eureka family of Martian Trojan asteroids

NASA Astrophysics Data System (ADS)

Borisov, Galin; Christou, Apostolos; Bagnulo, Stefano

2016-10-01

The so-called Martian Trojan asteroids orbit the Sun just inside the terrestrial planet region. They are thought to date from the earliest period of the solar system's history (Scholl et al, Icarus, 2005). Recently, Christou (Icarus, 2013) identified an orbital concentration of Trojans, named the "Eureka" cluster after its largest member, 5261 Eureka. This asteroid belongs to the rare olivine-rich A taxonomic class (Rivkin et al, Icarus, 2007; Lim et al, DPS/EPSC 2011). Unlike asteroids belonging to other taxonomies (e.g. C or S), no orbital concentrations or families of A-types are currently known to exist. These asteroids may represent samples of the building blocks that came together to form Mars and the other terrestrial planets but have since been destroyed by collisions (Sanchez et al, Icarus, 2014, and references therein).We have used the X-SHOOTER echelle spectrograph on the ESO VLT KUEYEN to obtain vis-NIR reflectance spectra of asteroids in the cluster and test their genetic relationship to Eureka. During the presentation we will show the spectra, compare them with available spectra for Eureka itself and discuss the implications for the origin of this cluster and for other olivine-dominated asteroids in the Main Belt.Based on observations made with ESO Telescopes at the La Silla-Paranal Observatory under programme ID 296.C-5030 (PI: A. Christou). Astronomical Research at Armagh Observatory is funded by the Northern Ireland Department of Culture, Arts and Leisure (DCAL).

Hunting the parent of the Orphan stream. II. The first high-resolution spectroscopic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Casey, Andrew R.; Keller, Stefan C.; Da Costa, Gary

2014-03-20

We present the first high-resolution spectroscopic study on the Orphan stream for five stream candidates, observed with the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Clay telescope. The targets were selected from the low-resolution catalog of Casey et al.: three high-probability members, one medium, and one low-probability stream candidate were observed. Our analysis indicates that the low- and medium-probability targets are metal-rich field stars. The remaining three high-probability targets range over ∼1 dex in metallicity, and are chemically distinct compared to the other two targets and all standard stars: low [α/Fe] abundance ratios are observed, and lower limits aremore » ascertained for [Ba/Y], which sit well above the Milky Way trend. These chemical signatures demonstrate that the undiscovered parent system is unequivocally a dwarf spheroidal galaxy, consistent with dynamical constraints inferred from the stream width and arc. As such, we firmly exclude the proposed association between NGC 2419 and the Orphan stream. A wide range in metallicities adds to the similarities between the Orphan stream and Segue 1, although the low [α/Fe] abundance ratios in the Orphan stream are in tension with the high [α/Fe] values observed in Segue 1. Open questions remain before Segue 1 could possibly be claimed as the 'parent' of the Orphan stream. The parent system could well remain undiscovered in the southern sky.« less

The Composition of Comet C 2012 K1 (PanSTARRS) and the Distribution of Primary Volatile Abundances Among Comets

NASA Technical Reports Server (NTRS)

Roth, Nathan X.; Gibb, Erika; Bonev, Boncho P.; Disanti, Michael A.; Mumma, Michael J.; Villanueva, Geronimo L.; Paganini, Lucas

2017-01-01

On 2014 May 22 and 24 we characterized the volatile composition of the dynamically new Oort cloud comet C2012 K1 (PanSTARRS) using the long-slit, high resolution ( lambda/delta lambda is approximately or equal to 25,000) near-infrared echelle spectrograph (NIRSPEC) at the 10 m Keck II telescope on Maunakea, Hawaii. We detected fluorescent emission from six primary volatiles (H2O, HCN, CH4, C2H6, CH3OH, and CO). Upper limits were derived for C2H2, NH3, and H2CO. We report rotational temperatures, production rates, and mixing ratios (relative to water). Compared with median abundance ratios for primary volatiles in other sampled Oort cloud comets, trace gas abundance ratios in C2012 K1 (PanSTARRS) for CO and HCN are consistent, but CH3OH and C2H6 are enriched while H2CO, CH4, and possibly C2H2 are depleted. When placed in context with comets observed in the near- infrared to date, the data suggest a continuous distribution of abundances of some organic volatiles (HCN, C2H6, CH3OH, CH4) among the comet population. The level of enrichment or depletion in a given comet does not necessarily correlate across all molecules sampled, suggesting that chemical diversity among comets may be more complex than the simple organics-enriched, organics-normal, and organics-depleted framework.

Integration, commissioning, and performance of the UK FMOS spectrograph

NASA Astrophysics Data System (ADS)

Dalton, Gavin B.; Lewis, Ian J.; Tosh, Ian A. J.; Blackburn, Colin; Bonfield, David G.; Brooks, Charles B.; Holmes, Alan R.; Lee, Hanshin; Froud, Tim R.; Akiyama, Masayuki; Tamura, Naoyuki; Takato, Naruhisa

2008-07-01

The UK FMOS spectrograph forms part of Subaru's FMOS multi-object infrared spectroscopy facility. The spectrograph was shipped to Hilo in component form in August of 2007. We describe the integration sequence for the spectrograph, the results of cooldown tests using a new chiller unit fitted to the spectrograph at the telescope, and alignment tests of the spectrograph, gratings and OH-suppression masks. We present the first-light observations for the spectrograph from May 2008.

The Effectiveness of Vowel Production Training with Real-Time Spectrographic Displays for Children with Profound Hearing Impairment.

NASA Astrophysics Data System (ADS)

Ertmer, David Joseph

1994-01-01

The effectiveness of vowel production training which incorporated direct instruction in combination with spectrographic models and feedback was assessed for two children who exhibited profound hearing impairment. A multiple-baseline design across behaviors, with replication across subjects was implemented to determine if vowel production accuracy improved following the introduction of treatment. Listener judgments of vowel correctness were obtained during the baseline, training, and follow-up phases of the study. Data were analyzed through visual inspection of changes in levels of accuracy, changes in trends of accuracy, and changes in variability of accuracy within and across phases. One subject showed significant improvement of all three trained vowel targets; the second subject for the first trained target only (Kolmogorov-Smirnov Two Sample Test). Performance trends during training sessions suggest that continued treatment would have resulted in further improvement for both subjects. Vowel duration, fundamental frequency, and the frequency locations of the first and second formants were measured before and after training. Acoustic analysis revealed highly individualized changes in the frequency locations of F1 and F2. Vowels which received the most training were maintained at higher levels than those which were introduced later in training, Some generalization of practiced vowel targets to untrained words was observed in both subjects. A bias towards judging productions as "correct" was observed for both subjects during self-evaluation tasks using spectrographic feedback.

The OD/OH Isotope Ratio in Comets 8P/Tuttle and C/2012 F6 (Lemmon)

NASA Astrophysics Data System (ADS)

Rousselot, Philippe; Jehin, Emmanuel; Hutsemekers, Damien; Manfroid, Jean; Decock, Alice; Bockelee-Morvan, Dominique

2016-10-01

The determination of isotopic ratios in solar system objects is an important source of information about their origin, especially for comets. Among these ratios the D/H is of particular importance because of its sensitivity to fractionation processes and physical environment, and the abundance of hydrogen in the solar system. The main molecule used to derive this ratio in comets is water. So far, apart water, only HCN has permitted to derive D/H ratio and not only upper limits.Most of the existing determinations of D/H in water molecules have been obtained by spectroscopic observations of water lines in the sub-mm or near infrared range [1,2]. So far only one measurement has been based on OD/OH emission lines radicals in the near-UV [3] and another one on the Lyman-alpha D emission [4]. In situ measurements have also been obtained in comets 1P/Halley and 67P/Churyumov-Gerasimenko using mass spectrometer [5,6,7,8].In this work we have used the OH and OD ultraviolet bands at 310 nm observed with the ESO 8-m Very Large Telescope feeding the Ultraviolet-Visual Echelle Spectrograph (UVES) for measuring the D/H ratio in comets 8P/Tuttle and C/2012 F6 (Lemmon). The OH and OD being the photodissociation products of H2O and HDO such observations allow to derive D/H ratio for water molecules. This work constitutes an independant determination of the D/H ratios already published for these comets and based on observations performed in the sub-mm and near infrared range of H2O and HDO lines. We present our modeling, data analysis and numerical values obtained for this ratio.[1] D. Bockelée-Morvan et al., 2015, SSR 197, 47-83 [2] N. Biver et al., 2016, A&A 589, id A78, 11p [3] D. Hutsemékers et al., 2008, A&A 490, L31 [4] H.A. Weaver et al., 2008, LPI Contributions 1405, 8216 [5] H. Balsiger, K. Altwegg, J. Geiss, 1995, JGR 100, 5827 [6] P. Eberhardt et al., 1995, A&A 302, 301 [7] R.H. Brown et al., 2012, PSS 60, 166 [8] K. Alwegg et al., 2015, Science 347, article id. 1261952

The K2 M67 Study: A Curiously Young Star in an Eclipsing Binary in an Old Open Cluster

NASA Astrophysics Data System (ADS)

Sandquist, Eric L.; Mathieu, Robert D.; Quinn, Samuel N.; Pollack, Maxwell L.; Latham, David W.; Brown, Timothy M.; Esselstein, Rebecca; Aigrain, Suzanne; Parviainen, Hannu; Vanderburg, Andrew; Stello, Dennis; Somers, Garrett; Pinsonneault, Marc H.; Tayar, Jamie; Orosz, Jerome A.; Bedin, Luigi R.; Libralato, Mattia; Malavolta, Luca; Nardiello, Domenico

2018-04-01

We present an analysis of a slightly eccentric (e = 0.05), partially eclipsing, long-period (P = 69.73 days) main-sequence binary system (WOCS 12009, Sanders 1247) in the benchmark old open cluster M67. Using Kepler K2 and ground-based photometry, along with a large set of new and reanalyzed spectra, we derived highly precise masses (1.111 ± 0.015 and 0.748 ± 0.005 M ⊙) and radii (1.071 ± 0.008 ± 0.003 and 0.713 ± 0.019 ± 0.026 R ⊙, with statistical and systematic error estimates) for the stars. The radius of the secondary star is in agreement with theory. The primary, however, is approximately 15% smaller than reasonable isochrones for the cluster predict. Our best explanation is that the primary star was produced from the merger of two stars, as this can also account for the nondetection of photospheric lithium and its higher temperature relative to other cluster main-sequence stars at the same V magnitude. To understand the dynamical characteristics (low measured rotational line broadening of the primary star and low eccentricity of the current binary orbit), we believe that the most probable (but not the only) explanation is the tidal evolution of a close binary within a primordial triple system (possibly after a period of Kozai–Lidov oscillations), leading to merger approximately 1 Gyr ago. This star appears to be a future blue straggler that is being revealed as the cluster ages and the most massive main-sequence stars die out. Based on observations made at Kitt Peak National Observatory, National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation; with the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5 m Tillinghast telescope, located at the Smithsonian Astrophysical Observatory’s Fred L. Whipple Observatory on Mt. Hopkins in Arizona; the HARPS-N spectrograph on the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the INAF Fundacion Galileo Galilei (Spanish Observatory of Roque de los Muchachos of the IAC); and the Las Cumbres Observatory Global Telescope network.

PEPSI: The high-resolution échelle spectrograph and polarimeter for the Large Binocular Telescope

NASA Astrophysics Data System (ADS)

Strassmeier, K. G.; Ilyin, I.; Järvinen, A.; Weber, M.; Woche, M.; Barnes, S. I.; Bauer, S.-M.; Beckert, E.; Bittner, W.; Bredthauer, R.; Carroll, T. A.; Denker, C.; Dionies, F.; DiVarano, I.; Döscher, D.; Fechner, T.; Feuerstein, D.; Granzer, T.; Hahn, T.; Harnisch, G.; Hofmann, A.; Lesser, M.; Paschke, J.; Pankratow, S.; Plank, V.; Plüschke, D.; Popow, E.; Sablowski, D.

2015-05-01

PEPSI is the bench-mounted, two-arm, fibre-fed and stabilized Potsdam Echelle Polarimetric and Spectroscopic Instrument for the 2×8.4 m Large Binocular Telescope (LBT). Three spectral resolutions of either 43 000, 120 000 or 270 000 can cover the entire optical/red wavelength range from 383 to 907 nm in three exposures. Two 10.3k×10.3k CCDs with 9-μm pixels and peak quantum efficiencies of 94-96 % record a total of 92 échelle orders. We introduce a new variant of a wave-guide image slicer with 3, 5, and 7 slices and peak efficiencies between 92-96 %. A total of six cross dispersers cover the six wavelength settings of the spectrograph, two of them always simultaneously. These are made of a VPH-grating sandwiched by two prisms. The peak efficiency of the system, including the telescope, is 15 % at 650 nm, and still 11 % and 10 % at 390 nm and 900 nm, respectively. In combination with the 110 m2 light-collecting capability of the LBT, we expect a limiting magnitude of ≈ 20th mag in V in the low-resolution mode. The R = 120 000 mode can also be used with two, dual-beam Stokes IQUV polarimeters. The 270 000-mode is made possible with the 7-slice image slicer and a 100-μm fibre through a projected sky aperture of 0.74 arcsec, comparable to the median seeing of the LBT site. The 43 000-mode with 12-pixel sampling per resolution element is our bad seeing or faint-object mode. Any of the three resolution modes can either be used with sky fibers for simultaneous sky exposures or with light from a stabilized Fabry-Pérot étalon for ultra-precise radial velocities. CCD-image processing is performed with the dedicated data-reduction and analysis package PEPSI-S4S. Its full error propagation through all image-processing steps allows an adaptive selection of parameters by using statistical inferences and robust estimators. A solar feed makes use of PEPSI during day time and a 500-m feed from the 1.8 m VATT can be used when the LBT is busy otherwise. In this paper, we present the basic instrument design, its realization, and its characteristics. Some pre-commissioning first-light spectra shall demonstrate the basic functionality.

Silicon immersion gratings and their spectroscopic applications

NASA Astrophysics Data System (ADS)

Ge, Jian; Zhao, Bo; Powell, Scott; Fletcher, Adam; Wan, Xiaoke; Chang, Liang; Jakeman, Hali; Koukis, Dimitrios; Tanner, David B.; Ebbets, Dennis; Weinberg, Jonathan; Lipscy, Sarah; Nyquist, Rich; Bally, John

2012-09-01

Silicon immersion gratings (SIGs) offer several advantages over the commercial echelle gratings for high resolution infrared (IR) spectroscopy: 3.4 times the gain in dispersion or ~10 times the reduction in the instrument volume, a multiplex gain for a large continuous wavelength coverage and low cost. We present results from lab characterization of a large format SIG of astronomical observation quality. This SIG, with a 54.74 degree blaze angle (R1.4), 16.1 l/mm groove density, and 50x86 mm2 grating area, was developed for high resolution IR spectroscopy (R~70,000) in the near IR (1.1-2.5 μm). Its entrance surface was coated with a single layer of silicon nitride antireflection (AR) coating and its grating surface was coated with a thin layer of gold to increase its throughput at 1.1-2.5 μm. The lab measurements have shown that the SIG delivered a spectral resolution of R=114,000 at 1.55 μm with a lab testing spectrograph with a 20 mm diameter pupil. The measured peak grating efficiency is 72% at 1.55 μm, which is consistent with the measurements in the optical wavelengths from the grating surface at the air side. This SIG is being implemented in a new generation cryogenic IR spectrograph, called the Florida IR Silicon immersion grating spectrometer (FIRST), to offer broad-band high resolution IR spectroscopy with R=72,000 at 1.4-1.8 um under a typical seeing condition in a single exposure with a 2kx2k H2RG IR array at the robotically controlled Tennessee State University 2-meter Automatic Spectroscopic Telescope (AST) at Fairborn Observatory in Arizona. FIRST is designed to provide high precision Doppler measurements (~4 m/s) for the identification and characterization of extrasolar planets, especially rocky planets in habitable zones, orbiting low mass M dwarf stars. It will also be used for other high resolution IR spectroscopic observations of such as young stars, brown dwarfs, magnetic fields, star formation and interstellar mediums. An optimally designed SIG of the similar size can be used in the Silicon Immersion Grating Spectrometer (SIGS) to fill the need for high resolution spectroscopy at mid IR to far IR (~25-300 μm) for the NASA SOFIA airborne mission in the future.

Spectroscopic investigation of stars on the lower main sequence

NASA Astrophysics Data System (ADS)

Mishenina, T. V.; Soubiran, C.; Bienaymé, O.; Korotin, S. A.; Belik, S. I.; Usenko, I. A.; Kovtyukh, V. V.

2008-10-01

Aims: The aim of this paper is to provide fundamental parameters and abundances with a high accuracy for a large sample of cool main sequence stars. This study is part of wider project, in which the metallicity distribution of the local thin disc is investigated from a complete sample of G and K dwarfs within 25 pc. Methods: The stars were observed at high resolution and a high signal-to-noise ratio with the ELODIE echelle spectrograph. The V sin i were obtained with a calibration of the cross-correlation function. Effective temperatures were estimated by the line depth ratio method. Surface gravities (log g) were determined by two methods: parallaxes and ionization balance of iron. The Mg and Na abundances were derived using a non-LTE approximation. Abundances of other elements were obtained by measuring equivalent widths. Results: Rotational velocities, atmospheric parameters (T_eff, log g, [Fe/H], V_t), and Li, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Co, Ni, and Zn abundances are provided for 131 stars. Among them, more than 30 stars are active stars with a fraction of BY Dra and RS CVn type stars for which spectral peculiarities were investigated. We find the mean abundances of the majority of elements in active and nonactive stars to be similar, except for Li, and possibly for Zn and Co. The lithium is reliably detected in 54% of active stars but only in 20% of nonactive stars. No correlation is found between Li abundances and rotational velocities. A possible anticorrelation of log A(Li) with the index of chromospheric activity GrandS is observed. Conclusions: Active and nonactive cool dwarfs show similar dependencies of most elemental ratios vs. [Fe/H]. This allows us to use such abundance ratios to study the chemical and dynamical evolution of the Galaxy. Among active stars, no clear correlation has been found between different indicators of activity for our sample stars. Based on spectra collected with the ELODIE spectrograph at the 1.93-m telescope of the Observatoire de Haute Provence (France). Tables A.1-A3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/489/923

Massive binary stars as a probe of massive star formation

NASA Astrophysics Data System (ADS)

Kiminki, Daniel C.

2010-10-01

Massive stars are among the largest and most influential objects we know of on a sub-galactic scale. Binary systems, composed of at least one of these stars, may be responsible for several types of phenomena, including type Ib/c supernovae, short and long gamma ray bursts, high-velocity runaway O and B-type stars, and the density of the parent star clusters. Our understanding of these stars has met with limited success, especially in the area of their formation. Current formation theories rely on the accumulated statistics of massive binary systems that are limited because of their sample size or the inhomogeneous environments from which the statistics are collected. The purpose of this work is to provide a higher-level analysis of close massive binary characteristics using the radial velocity information of 113 massive stars (B3 and earlier) and binary orbital properties for the 19 known close massive binaries in the Cygnus OB2 Association. This work provides an analysis using the largest amount of massive star and binary information ever compiled for an O-star rich cluster like Cygnus OB2, and compliments other O-star binary studies such as NGC 6231, NGC 2244, and NGC 6611. I first report the discovery of 73 new O or B-type stars and 13 new massive binaries by this survey. This work involved the use of 75 successful nights of spectroscopic observation at the Wyoming Infrared Observatory in addition to observations obtained using the Hydra multi-object spectrograph at WIYN, the HIRES echelle spectrograph at KECK, and the Hamilton spectrograph at LICK. I use these data to estimate the spectrophotometric distance to the cluster and to measure the mean systemic velocity and the one-sided velocity dispersion of the cluster. Finally, I compare these data to a series of Monte Carlo models, the results of which indicate that the binary fraction of the cluster is 57 +/- 5% and that the indices for the power law distributions, describing the log of the periods, mass-ratios, and eccentricities, are --0.2 +/- 0.3, 0.3 +/- 0.3, and --0.8 +/- 0.3 respectively (or not consistent with a simple power law distribution). The observed distributions indicate a preference for short period systems with nearly circular orbits and companions that are not likely drawn from a standard initial mass function, as would be expected from random pairing. An interesting and unexpected result is that the period distribution is inconsistent with a standard power-law slope stemming mainly from an excess of periods between 3 and 5 days and an absence of periods between 7 and 14 days. One possible explanation of this phenomenon is that the binary systems with periods from 7--14 days are migrating to periods of 3--5 days. In addition, the binary distribution here is not consistent with previous suggestions in the literature that 45% of OB binaries are members of twin systems (mass ratio near 1).

Unexpected series of regular frequency spacing of δ Scuti stars in the non-asymptotic regime - I. The methodology

DOE PAGES

Paparo, M.; Benko, J. M.; Hareter, M.; ...

2016-05-11

In this study, a sequence search method was developed to search the regular frequency spacing in δ Scuti stars through visual inspection and an algorithmic search. We searched for sequences of quasi-equally spaced frequencies, containing at least four members per sequence, in 90 δ Scuti stars observed by CoRoT. We found an unexpectedly large number of independent series of regular frequency spacing in 77 δ Scuti stars (from one to eight sequences) in the non-asymptotic regime. We introduce the sequence search method presenting the sequences and echelle diagram of CoRoT 102675756 and the structure of the algorithmic search. Four sequencesmore » (echelle ridges) were found in the 5–21 d –1 region where the pairs of the sequences are shifted (between 0.5 and 0.59 d –1) by twice the value of the estimated rotational splitting frequency (0.269 d –1). The general conclusions for the whole sample are also presented in this paper. The statistics of the spacings derived by the sequence search method, by FT (Fourier transform of the frequencies), and the statistics of the shifts are also compared. In many stars more than one almost equally valid spacing appeared. The model frequencies of FG Vir and their rotationally split components were used to formulate the possible explanation that one spacing is the large separation while the other is the sum of the large separation and the rotational frequency. In CoRoT 102675756, the two spacings (2.249 and 1.977 d –1) are in better agreement with the sum of a possible 1.710 d –1 large separation and two or one times, respectively, the value of the rotational frequency.« less

Unexpected series of regular frequency spacing of δ Scuti stars in the non-asymptotic regime - I. The methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paparo, M.; Benko, J. M.; Hareter, M.

In this study, a sequence search method was developed to search the regular frequency spacing in δ Scuti stars through visual inspection and an algorithmic search. We searched for sequences of quasi-equally spaced frequencies, containing at least four members per sequence, in 90 δ Scuti stars observed by CoRoT. We found an unexpectedly large number of independent series of regular frequency spacing in 77 δ Scuti stars (from one to eight sequences) in the non-asymptotic regime. We introduce the sequence search method presenting the sequences and echelle diagram of CoRoT 102675756 and the structure of the algorithmic search. Four sequencesmore » (echelle ridges) were found in the 5–21 d –1 region where the pairs of the sequences are shifted (between 0.5 and 0.59 d –1) by twice the value of the estimated rotational splitting frequency (0.269 d –1). The general conclusions for the whole sample are also presented in this paper. The statistics of the spacings derived by the sequence search method, by FT (Fourier transform of the frequencies), and the statistics of the shifts are also compared. In many stars more than one almost equally valid spacing appeared. The model frequencies of FG Vir and their rotationally split components were used to formulate the possible explanation that one spacing is the large separation while the other is the sum of the large separation and the rotational frequency. In CoRoT 102675756, the two spacings (2.249 and 1.977 d –1) are in better agreement with the sum of a possible 1.710 d –1 large separation and two or one times, respectively, the value of the rotational frequency.« less

SpecTracer: A Python-Based Interactive Solution for Echelle Spectra Reduction

NASA Astrophysics Data System (ADS)

Romero Matamala, Oscar Fernando; Petit, Véronique; Caballero-Nieves, Saida Maria

2018-01-01

SpecTracer is a newly developed interactive solution to reduce cross dispersed echelle spectra. The use of widgets saves the user the steep learning curves of currently available reduction software. SpecTracer uses well established image processing techniques based on IRAF to succesfully extract the stellar spectra. Comparisons with other reduction software, like IRAF, show comparable results, with the added advantages of ease of use, platform independence and portability. This tool can obtain meaningful scientific data and serve also as a training tool, especially for undergraduates doing research, in the procedure for spectroscopic analysis.

Elemental abundance analyses with Complejo Astronomico EL Leoncito REOSC echelle spectrograms. III. HR 4487, 14 Hydrae, and 3 Centauri A

NASA Astrophysics Data System (ADS)

Pintado, O. I.; Adelman, S. J.; Gulliver, A. F.

1998-05-01

Using CASLEO echelle spectrograms, elemental abundances are derived for the sharp-lined non-magnetic CP stars HR 4487, 14 Hya, and 3 Cen A. The first two stars are members of the Mercury-Manganese subgroup and have abundances which are similar to other such peculiar stars. The third is a hotter related star. The detection of Mn II lines in its spectrum adds to this relationship. Table 3 is avaible electronically vit the CDS via anonymous ftp 130.79.128.5 or http://cdsweb.u-strasbg.fr/Abstract.html.

High resolution middle infrared spectrometer, a part of atmospheric chemistry suite (ACS) for EXOMARS 2016 trace gas orbiter

NASA Astrophysics Data System (ADS)

Trokhimovskiy, Alexander; Korablev, Oleg; Ivanov, Yurii; Syniavskyi, Ivan; Montmessin, Franck; Fedorova, Anna

2017-11-01

The Atmospheric Chemistry Suite (ACS) package is a part of Russian contribution to ExoMars ESARoscosmos mission for studies of the Martian atmosphere and climate. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. The mid-infrared (MIR) channel is a cross-dispersion high resolution echelle instrument dedicated to solar occultation measurements and sensitive studies of trace gases. The MIR channel is a spectrometer working in 2.3-4.2 μm spectral range, covering simultaneously up to almost 300 nm per exposure, targeting the resolving power of 50,000. A crossdispersion concept on echelle and ordinary diffraction grating allows acquisition of the wide wavelength domain at once. That provides a strategic advantage for maximizing the number of gaseous species detected simultaneously and good special resolution of measurements during fast occultation sessions. Moving the second grating allows to switch from one group of the diffraction orders to another prior to a series of measurements, or desired positions during one measurement sequence. The concept of the cross-dispersion echelle instrument, which is widely accepted in astronomy, has been already employed in planetary missions with VIRTIS-H instrument presently in flight on Rosetta and Venus Express missions. Targeting very high spectral resolution the MIR channel operates in solar occultation only. A telescope with relative aperture of 1∶3 forms the image of the solar disk on the slit. The FOV is determined by the slit and it consists 0.1×2.9 mrad. The spectral resolution of the spectrometer is fully slit-limited, and the resolving power of λ/Δλ >= 50000 at 3.3 μm is supported. Two secondary cross-dispersion diffraction gratings (plain, 180 and 361 grooves per mm) are mounted back-to-back on a stepper motor to change observed echelle orders. We have chosen two secondary gratings philosophy to switch between them depending on the long or short wavelength range we are on. Changing the position of the secondary grating in angular steps of 1.8°, from 10 to 30 echelle orders are available for simultaneous record depending on the wavelength. 100 steps are evidently used to switch between gratings prior measurements. The full spectral range is covered on diffraction orders from 142 to 248. For each observation detector area is covered by 10 to 30 stripes, each corresponding to single echelle diffraction order. Given the complexity of the diffraction orders pattern, full detector frames will be transmitted to the ground, with lossless compression. However, the onboard averaging will be possible. Single data frame will be accumulated for 0.5 seconds, stacking of a number of shorter exposures.

PESO - The Python Based Control System of the Ondrejov 2m Telescope

NASA Astrophysics Data System (ADS)

Skoda, P.; Fuchs, J.; Honsa, J.

2005-12-01

Python has been gaining a good reputation and respectability in many areas of software development. We have chosen Python after getting the new CCD detector for the coudé spectrograph of Ondřejov observatory 2m telescope. The VersArray detector from Roper Scientific came only with the closed source library PVCAM of low-level camera control functions for Linux, so we had to write the whole astronomical data acquisition system from scratch and integrate it with the current spectrograph and telescope control systems. The final result of our effort, PESO (Python Exposure System for Ondřejov) is a highly comfortable GUI-based environment allowing the observer to change the spectrograph configuration, choose the detector acquisition mode, select the exposure parameters, and monitor the exposure progress. All of the relevant information from the control computers is written into the FITS headers by the PyFITS module, and the acquired CCD frame is immediately displayed in an SAO DS9 window using XPA calls. The GTK-based front end design was drawn in the Glade visual development tool, giving the shape and position of all widgets in single XML file, which is used in Python by a simple call of the PyGlade module. We describe our experience with the design and implementation of PESO, stressing the easiness of quick changes of the GUI, together with the capability of separate testing of every module using the Python debugger, IPython.

Thick-SOI Echelle grating for any-to-any wavelength routing interconnection in multi-socket computing environments

NASA Astrophysics Data System (ADS)

Dabos, G.; Pitris, S.; Mitsolidou, C.; Alexoudi, T.; Fitsios, D.; Cherchi, M.; Harjanne, M.; Aalto, T.; Kanellos, G. T.; Pleros, N.

2017-02-01

As data centers constantly expand, electronic switches are facing the challenge of enhanced scalability and the request for increased pin-count and bandwidth. Photonic technology and wavelength division multiplexing have always been a strong alternative for efficient routing and their potential was already proven in the telecoms. CWDM transceivers have emerged in the board-to-board level interconnection, revealing the potential for wavelength-routing to be applied in the datacom and an AWGR-based approach has recently been proposed towards building an optical multi-socket interconnection to offer any-to-any connectivity with high aggregated throughput and reduced power consumption. Echelle gratings have long been recognized as the multiplexing block exhibiting smallest footprint and robustness in a wide number of applications compared to other alternatives such as the Arrayed Waveguide Grating. Such filtering devices can also perform in a similar way to cyclical AWGR and serve as mid-board routing platforms in multi-socket environments. In this communication, we present such a 3x3 Echelle grating integrated on thick SOI platform with aluminum-coated facets that is shown to perform successful wavelength-routing functionality at 10 Gb/s. The device exhibits a footprint of 60x270 μm2, while the static characterization showed a 3 dB on-chip loss for the best channel. The 3 dB-bandwidth of the channels was 4.5 nm and the free spectral range was 90 nm. The echelle was evaluated in a 2x2 wavelength routing topology, exhibiting a power penalty of below 0.4 dB at 10-9 BER for the C-band. Further experimental evaluations of the platform involve commercially available CWDM datacenter transceivers, towards emulating an optically-interconnected multi-socket environment traffic scenario.

Fixed Delay Interferometry for Doppler Extrasolar Planet Detection

NASA Astrophysics Data System (ADS)

Ge, Jian

2002-06-01

We present a new technique based on fixed delay interferometry for high-throughput, high-precision, and multiobject Doppler radial velocity (RV) surveys for extrasolar planets. The Doppler measurements are conducted by monitoring the stellar fringe phase shifts of the interferometer instead of absorption-line centroid shifts as in state-of-the-art echelle spectroscopy. High Doppler sensitivity is achieved through optimizing the optical delay in the interferometer and reducing photon noise by measuring multiple fringes over a broad band. This broadband operation is performed by coupling the interferometer with a low- to medium-resolution postdisperser. The resulting fringing spectra over the bandpass are recorded on a two-dimensional detector, with fringes sampled in the slit spatial direction and the spectrum sampled in the dispersion direction. The resulting total Doppler sensitivity is, in theory, independent of the dispersing power of the postdisperser, which allows for the development of new-generation RV machines with much reduced size, high stability, and low cost compared to echelles. This technique has the potential to improve RV survey efficiency by 2-3 orders of magnitude over the cross-dispersed echelle spectroscopy approach, which would allow a full-sky RV survey of hundreds of thousands of stars for planets, brown dwarfs, and stellar companions once the instrument is operated as a multiobject instrument and is optimized for high throughput. The simple interferometer response potentially allows this technique to be operated at other wavelengths independent of popular iodine reference sources, being actively used in most of the current echelles for Doppler planet searches, to search for planets around early-type stars, white dwarfs, and M, L, and T dwarfs for the first time. The high throughput of this instrument could also allow investigation of extragalactic objects for RV variations at high precision.

THE OPTICAL WIND LINE VARIABILITY OF η CARINAE DURING THE 2009.0 EVENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, N. D.; Moffat, A. F. J.; St-Jean, L.

2015-10-15

We report on high-resolution spectroscopy of the 2009.0 spectroscopic event of η Carinae collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two-month interval around the photometric minimum of η Car associated with the periastron passage of a hot companion. The photoionizing flux of the companion and heating related to colliding winds causes large changes in the wind properties of the massive primary star. Here we present an analysis of temporal variations in a sample of spectral lines that are clearly formed in the wind of themore » primary star. These lines are affected by a changing illumination of the flux of the secondary star during the periastron passage. We document the sudden onset of blueshifted absorption that occurred in most of the lines near or slightly after periastron, and we argue that these absorption components are seen when we view the relatively undisturbed wind of the foreground primary star. We present time series measurements of the net equivalent width of the wind lines and of the radial velocities of the absorption trough minima and the emission peak midpoints. Most lines decrease in emission strength around periastron, and those high excitation lines formed close to the primary exhibit a red-ward velocity excursion. We show how these trends can be explained using an illuminated hemisphere model that is based on the idea that the emission originates primarily from the side of the primary facing the hot companion.« less

Orbital and Systemic Parameters for Algol Binaries in the Field-of-View of the Kepler Spacecraft

NASA Astrophysics Data System (ADS)

Peters, Geraldine J.; Vaccaro, Todd R.; Wilson, Robert E.

2013-02-01

We propose observations of seven Algol-type binaries with the 4m Echelle spectrograph necessary for the interpretation of ongoing photometry from the it Kepler spacecraft and archival it Kepler data being analyzed for an approved NASA/ADAP project. These Algols are direct-impact systems (periods range from 1.3-4.5^d) in which the gas stream strikes the photosphere of the gainer, producing a shock. The it Kepler light curves reveal striking long and short-term variability never before seen in ground-based observations. Especially interesting is a long-term oscillation in the relative brightness of the quadrature light that we call L/T variability, which appears to be caused from a migrating variable hot spot. The it Kepler photometry is being interpreted with an updated version of the Wilson & Devinney (WD) program. The KPNO spectra will supply it critical input parameters (e.g. temperatures) and yield radial velocity curves from which we will determine the masses of the stars and absolute dimensions of the systems. Currently there are it no published spectra of most of the program binaries, including WX Dra, the prototype L/T variable and our primary target. We request 4 nights of observing time to cover one orbital cycle in the binaries with the longest periods. This project will yield information on the detailed physics of mass transfer, especially the roles of accretion hot spots and magnetic fields, and also test the new WD program for future applications by others working with the it Kepler database.

Evolution of H2O, CO, and CO2 production in Comet C/2009 P1 Garradd during the 2011-2012 apparition

NASA Astrophysics Data System (ADS)

McKay, Adam J.; Cochran, Anita L.; DiSanti, Michael A.; Villanueva, Geronimo; Russo, Neil Dello; Vervack, Ronald J.; Morgenthaler, Jeffrey P.; Harris, Walter M.; Chanover, Nancy J.

2015-04-01

We present analysis of high spectral resolution NIR spectra of CO and H2O in Comet C/2009 P1 (Garradd) taken during its 2011-2012 apparition with the CSHELL instrument on NASA's Infrared Telescope Facility (IRTF). We also present analysis of observations of atomic oxygen in Comet Garradd obtained with the ARCES echelle spectrometer mounted on the ARC 3.5-m telescope at Apache Point Observatory and the Tull Coude spectrograph on the Harlan J. Smith 2.7-m telescope at McDonald Observatory. The observations of atomic oxygen serve as a proxy for H2O and CO2. We confirm the high CO abundance in Comet Garradd and the asymmetry in the CO/H2O ratio with respect to perihelion reported by previous studies. From the oxygen observations, we infer that the CO2/H2O ratio decreased as the comet moved towards the Sun, which is expected based on current sublimation models. We also infer that the CO2/H2O ratio was higher pre-perihelion than post-perihelion. We observe evidence for the icy grain source of H2O reported by several studies pre-perihelion, and argue that this source is significantly less abundant post-perihelion. Since H2O, CO2, and CO are the primary ices in comets, they drive the activity. We use our measurements of these important volatiles in an attempt to explain the evolution of Garradd's activity over the apparition.

Search for Exoplanets around Northern Circumpolar Stars. II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742

NASA Astrophysics Data System (ADS)

Lee, Byeong-Cheol; Jeong, Gwanghui; Park, Myeong-Gu; Han, Inwoo; Mkrtichian, David E.; Hatzes, Artie P.; Gu, Shenghong; Bai, Jinming; Lee, Sang-Min; Oh, Hyeong-Il; Kim, Kang-Min

2017-07-01

We present the detection of long-period RV variations in HD 36384, HD 52030, and HD 208742 by using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) for the precise radial velocity (RV) survey of about 200 northern circumpolar stars. Analyses of RV data, chromospheric activity indicators, and bisector variations spanning about five years suggest that the RV variations are compatible with planet or brown dwarf companions in Keplerian motion. However, HD 36384 shows photometric variations with a period very close to that of RV variations as well as amplitude variations in the weighted wavelet Z-transform (WWZ) analysis, which argues that the RV variations in HD 36384 are from the stellar pulsations. Assuming that the companion hypothesis is correct, HD 52030 hosts a companion with minimum mass 13.3 M Jup orbiting in 484 days at a distance of 1.2 au. HD 208742 hosts a companion of 14.0 M Jup at 1.5 au with a period of 602 days. All stars are located at the asymptotic giant branch (AGB) stage on the H-R diagram after undergoing the helium flash and leaving the giant clump.With stellar radii of 53.0 R ⊙ and 57.2 R ⊙ for HD 52030 and HD 208742, respectively, these stars may be the largest yet, in terms of stellar radius, found to host substellar companions. However, given possible RV amplitude variations and the fact that these are highly evolved stars, the planet hypothesis is not yet certain.

Stellar parameters and H α line profile variability of Be stars in the BeSOS survey

NASA Astrophysics Data System (ADS)

Arcos, C.; Kanaan, S.; Chávez, J.; Vanzi, L.; Araya, I.; Curé, M.

2018-03-01

The Be phenomenon is present in about 20 per cent of B-type stars. Be stars show variability on a broad range of time-scales, which in most cases is related to the presence of a circumstellar disc of variable size and structure. For this reason, a time-resolved survey is highly desirable in order to understand the mechanisms of disc formation, which are still poorly understood. In addition, a complete observational sample would improve the statistical significance of the study of stellar and disc parameters. The `Be Stars Observation Survey' (BeSOS) is a survey containing reduced spectra obtained using the Pontifica Universidad Católica High Echelle Resolution Optical Spectrograph (PUCHEROS) with a spectral resolution of 17 000 in the range 4260-7300 Å. BeSOS's main objective is to offer consistent spectroscopic and time-resolved data obtained with one instrument. The user can download or plot the data and obtain stellar parameters directly from the website. We also provide a star-by-star analysis based on photometric, spectroscopic and interferometric data, as well as general information about the whole BeSOS sample. Recently, BeSOS led to the discovery of a new Be star HD 42167 and facilitated study of the V/R variation of HD 35165 and HD 120324, the steady disc of HD 110335 and the Be shell status of HD 127972. Optical spectra used in this work, as well as the stellar parameters derived, are available online at http://besos.ifa.uv.cl.

Homogeneous Characterization of Transiting Exoplanet Systems

NASA Astrophysics Data System (ADS)

Gomez Maqueo Chew, Yilen; Faedi, Francesca; Hebb, Leslie; Pollacco, Don; Stassun, Keivan; Ghezzi, Luan; Cargile, Phillip; Barros, Susana; Smalley, Barry; Mack, Claude

2012-02-01

We aim to obtain a homogeneous set of high resolution, high signal- to-noise (S/N) spectra for a large and diverse sample of stars with transiting planets, using the Kitt Peak 4-m echelle spectrograph for bright Northern targets (7.7150) in combination with high precision light curves shows an improvement in the precision of the stellar parameters of 60% in Teff, 75% in FeH, 82% in mstar, and 73% in rstar, which translates into a 64% improvement in the precision of rpl, and more than 2% on mpl, relative to the discovery paper's values.

Teacher Professional Development with SOFIA from Inception to Flight

NASA Astrophysics Data System (ADS)

Hemenway, Mary Kay; Lacy, J.; Sneden, C.; EXES Teacher Associates, SOFIA

2012-01-01

Since January 1998 Texas science and math teachers have met several times per year in a program centered on SOFIA, the Stratospheric Observatory for Infrared Astronomy. Initial meetings focused on astronomical instrumentation as the ground-based TEXES (Texas Echelon Cross Echelle Spectrograph) and its SOFIA successor, EXES, were developed and built. Sixty-nine different teachers have been involved in the seventy-nine Saturday meetings between January 1998 and October 2011. A typical meeting included an update on SOFIA, an expert talk on a science or technology topic, and a Standards-linked activity that they can carry back to use in their classrooms. Many of the participants have presented activities or reports to their colleagues. A variety of guest-presenters - faculty, staff, and graduate students as well as visitors (both in person and through videoconference) - enriched the program with their expertise. Some Saturday meetings included field trips to Waco to visit the SOFIA aircraft modification; other trips sent subsets of teachers to McDonald Observatory for TEXES' early observations, to Hawaii for observing runs on the IRTF or Gemini, and to various locations for American Astronomical Society meetings. The participants report their increased knowledge of astronomical concepts and of the culture of professional astronomy. By spreading the SOFIA EXES teacher program over such a long period, the staff has formed strong professional bonds with the participants while the participants have shared their experiences with each other. Support from USRA grant 8500-98-008; the National Science Foundation AST- 0607312, AST- 0607708, and AST-0908978; and SOFIA Education/Public Outreach through the SETI Institute 08-SC-1022 is gratefully acknowledged.

Identification of metal elements by time-resolved LIBS technique in sediments lake the “Cisne”

NASA Astrophysics Data System (ADS)

Pacheco, P.; Arregui, E.; Álvarez, J.; Rangel, N.; Sarmiento, R.

2017-01-01

Laser induced breakdown spectroscopy (LIBS), is a kind of spectral method of atomic emission that uses pulses of radiation high energy laser as excitation source. One of the advantages of technical LIBS lies in the possibility of analyse the substances in any State of aggregation, already is solid, liquid or gaseous, even in colloids as aerosols, gels and others. Another advantage over other conventional techniques is the simultaneous analysis of elements present in a sample of multielement. This work is made in the use of this technique for the identification of metal pollutants in the Swan Lake sediment samples, collected by drilling cores. Plasmas were generated by focusing the radiation of Nd: YAG laser with an energy per pulse 13mJ and 4ns duration, wavelength of 532nm. The spectra of radiation from the plasmas of sediment were recorded with an Echelle spectrograph type coupled to an ICCD camera. The delay times were between 0.5μs and 7μs, while the gate width was of 2μs. To ensure the homogeneity of the plasmas, the sediment sample was placed in a positioning system of linear and rotary adjustment of smooth step synchronized with the trigger of the laser pulse. The registration of the spectra of the sediment to different times of delay, allowed to identify the lines prominent of the different elements present in the sample. The analysis of the Spectra allowed the identification of some elements in the sample as if, Ca, Na, Mg, and Al through the measurement of wavelengths of the prominent peaks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roth, Nathan X.; Gibb, Erika L.; Bonev, Boncho P.

On 2014 May 22 and 24 we characterized the volatile composition of the dynamically new Oort cloud comet C/2012 K1 (PanSTARRS) using the long-slit, high resolution ( λ /Δ λ  ≈ 25,000) near-infrared echelle spectrograph (NIRSPEC) at the 10 m Keck II telescope on Maunakea, Hawaii. We detected fluorescent emission from six primary volatiles (H{sub 2}O, HCN, CH{sub 4}, C{sub 2}H{sub 6}, CH{sub 3}OH, and CO). Upper limits were derived for C{sub 2}H{sub 2}, NH{sub 3}, and H{sub 2}CO. We report rotational temperatures, production rates, and mixing ratios (relative to water). Compared with median abundance ratios for primary volatiles in other sampledmore » Oort cloud comets, trace gas abundance ratios in C/2012 K1 (PanSTARRS) for CO and HCN are consistent, but CH{sub 3}OH and C{sub 2}H{sub 6} are enriched while H{sub 2}CO, CH{sub 4}, and possibly C{sub 2}H{sub 2} are depleted. When placed in context with comets observed in the near-infrared to date, the data suggest a continuous distribution of abundances of some organic volatiles (HCN, C{sub 2}H{sub 6}, CH{sub 3}OH, CH{sub 4}) among the comet population. The level of “enrichment” or “depletion” in a given comet does not necessarily correlate across all molecules sampled, suggesting that chemical diversity among comets may be more complex than the simple organics-enriched, organics-normal, and organics-depleted framework.« less

A DETAILED FAR-ULTRAVIOLET SPECTRAL ATLAS OF MAIN-SEQUENCE B STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Myron A.

2010-02-01

We have constructed a detailed spectral atlas covering the wavelength region 930-1225 A for 10 sharp-lined B0-B9 stars near the main sequence. Most of the spectra we assembled are from the archives of the Far Ultraviolet Spectroscopic Explorer satellite, but for nine stars, wavelength coverage above 1188 A was taken from high-resolution International Ultraviolet Explorer or echelle Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra. To represent the tenth star at type B0.2 V, we used the Copernicus atlas of {tau} Sco. We made extensive line identifications in the region 949-1225 A of all atomic features having published oscillator strengths atmore » types B0, B2, and B8. These are provided as a supplementary data product-hence the term detailed atlas. Our list of found features totals 2288, 1612, and 2469 lines, respectively. We were able to identify 92%, 98%, and 98% of these features with known atomic transitions with varying degrees of certainty in these spectra. The remaining lines do not have published oscillator strengths. Photospheric lines account for 94%, 87%, and 91%, respectively, of all our identifications, with the remainder being due to interstellar (usually molecular H{sub 2}) lines. We also discuss the numbers of lines with respect to the distributions of various ions for these three most studied spectral subtypes. A table is also given of 162 least blended lines that can be used as possible diagnostics of physical conditions in B star atmospheres.« less

Brown dwarf distances and atmospheres: Spitzer Parallaxes and the Keck/NIRSPEC upgrade

NASA Astrophysics Data System (ADS)

Martin, Emily C.

2018-01-01

Advances in infrared technology have been essential towards improving our understanding of the solar neighborhood, revealing a large population of brown dwarfs, which span the mass regime between planets and stars. My thesis combines near-infrared (NIR) spectroscopic and astrometric analysis of nearby low-mass stars and brown dwarfs with instrumentation work to upgrade the NIRSPEC instrument for the Keck II Telescope. I will present results from a program using Spitzer/IRAC data to measure precise locations and distances to 22 of the coldest and closest brown dwarfs. These distances allow us to constrain absolute physical properties, such as mass, radius, and age, of free-floating planetary-mass objects through comparison to atmospheric and evolutionary models. NIR spectroscopy combined with the Spitzer photometry reveals a detailed look into the atmospheres of brown dwarfs and gaseous extrasolar planets. Additionally, I will discuss the improvements we are making to the NIRSPEC instrument at Keck. NIRSPEC is a NIR echelle spectrograph, capable of R~2000 and R~25,000 observations in the 1-5 μm range. As part of the upgrade, I performed detector characterization, optical design of a new slit-viewing camera, mechanical testing, and electronics design. NIRSPEC’s increased efficiency will allow us to obtain moderate- and high-resolution NIR spectra of objects up to a magnitude fainter than the current NIRSPEC design. Finally, I will demonstrate the utility of a NIR laser frequency comb as a high-resolution calibrator. This new technology will revolutionize precision radial velocity measurements in the coming decade.

VizieR Online Data Catalog: HD 176986 HARPS + HARPS-N data (Suarez Mascareno+, 2018)

NASA Astrophysics Data System (ADS)

Suarez Mascareno, A.; Gonzalez Hernandez, J. I.; Rebolo, R.; Velasco, S.; Toledo-Padron, B.; Udry, S.; Motalebi, F.; Segransan, D.; Wyttenbach, A.; Mayor, M.; Pepe, F.; Lovis, C.; Santos, N. C.; Figueira, P.; Esposito, M.

2017-11-01

HD 176986 has been extensively monitored since mid-2004 with HARPS and HARPS-N. The star was followed first in the HARPS planet-search programme on Guaranteed Time Observations (GTO, PI: M. Mayor) on-going for 6 years between autumn 2003 and spring 2009. The observations were then continued within the ESO Large Programs 183.C-0972+183.C-1005 (PI: S. Udry). Then it was observed with HARPS-N from 2014 onwards as part of the RoPES project using a nightly-cadence observation strategy aimed at the detection of very low-mass planets in close orbits of quiet G and K-type stars. HARPS Mayor2003 and HARPS-N Cosentino2012 are two fibre-fed high resolution echelle spectrographs installed at the 3.6m ESO telescope in La Silla Observatory (Chile) and at the Telescopio Nazionale Galileo in the Roque de los Muchachos Observatory (Spain), respectively. During the HARPS campaigns our star was typically observed once per night using an exposure time of 900s, with just a few exceptions. In the HARPS-N campaign the star was always observed using 3x300s exposures per visit, having one visit per night during the first years and two visits separated by a few hours during the 2016 and 2017 campaigns. The data is then re-sampled and averaged into 1 hour bins. The combination of both observational programmes provided 156 HARPS observations and 103 HARPS-N newly acquired observations, coming from 234 individual nights, during 13.2 years of observations. (1 data file).

Abundance Analysis of 17 Planetary Nebulae from High-Resolution Optical Spectroscopy

NASA Astrophysics Data System (ADS)

Sherrard, Cameroun G.; Sterling, Nicholas C.; Dinerstein, Harriet L.; Madonna, Simone; Mashburn, Amanda

2017-06-01

We present an abundance analysis of 17 planetary nebulae (PNe) observed with the 2D-coudé echelle spectrograph on the 2.7-m Harlan J. Smith telescope at McDonald Observatory. The spectra cover the wavelength range 3600--10,400 Å at a resolution R = 36,700, and are the first high-resolution optical spectra for many objects in our sample. The number of emission lines detected in individual nebulae range from ~125 to over 600. We derive temperatures, densities, and abundances from collisionally-excited lines using the PyNeb package (Luridiana et al. 2015, A&A, 573, A42) and the ionization correction factor scheme of Delgado-Inglada et al. (2014, MNRAS, 440, 536). The abundances of light elements agree with previous estimates for most of the PNe. Several objects exhibit emission lines of refractory elements such as K and Fe, and neutron-capture elements that can be enriched by the s-process. We find that K and Fe are depleted relative to solar by ~0.3--0.7~dex and 1-2 dex, respectively, and find evidence for s-process enrichments in 10 objects. Several objects in our sample exhibit C, N, and O recombination lines that are useful for abundance determinations. These transitions are used to compute abundance discrepancy factors (ADFs), the ratio of ionic abundances derived from permitted lines to those from collisionally-excited transitions. We explore relations among depletion factors, ADFs, s-process enrichment factors, and other nebular stellar and nebular properties. We acknowledge support from NSF awards AST-901432 and AST-0708429.

Compact Solid-State 213 nm Laser Enables Standoff Deep Ultraviolet Raman Spectrometer: Measurements of Nitrate Photochemistry.

PubMed

Bykov, Sergei V; Mao, Michael; Gares, Katie L; Asher, Sanford A

2015-08-01

We describe a new compact acousto-optically Q-switched diode-pumped solid-state (DPSS) intracavity frequency-tripled neodymium-doped yttrium vanadate laser capable of producing ~100 mW of 213 nm power quasi-continuous wave as 15 ns pulses at a 30 kHz repetition rate. We use this new laser in a prototype of a deep ultraviolet (UV) Raman standoff spectrometer. We use a novel high-throughput, high-resolution Echelle Raman spectrograph. We measure the deep UV resonance Raman (UVRR) spectra of solid and solution sodium nitrate (NaNO3) and ammonium nitrate (NH4NO3) at a standoff distance of ~2.2 m. For this 2.2 m standoff distance and a 1 min spectral accumulation time, where we only monitor the symmetric stretching band, we find a solid state NaNO3 detection limit of ~100 μg/cm(2). We easily detect ~20 μM nitrate water solutions in 1 cm path length cells. As expected, the aqueous solutions UVRR spectra of NaNO3 and NH4NO3 are similar, showing selective resonance enhancement of the nitrate (NO3(-)) vibrations. The aqueous solution photochemistry is also similar, showing facile conversion of NO3(-) to nitrite (NO2(-)). In contrast, the observed UVRR spectra of NaNO3 and NH4NO3 powders significantly differ, because their solid-state photochemistries differ. Whereas solid NaNO3 photoconverts with a very low quantum yield to NaNO2, the NH4NO3 degrades with an apparent quantum yield of ~0.2 to gaseous species.

Metallicity Evolution of Damped Lyα Systems Out to z ~ 5

NASA Astrophysics Data System (ADS)

Rafelski, Marc; Wolfe, Arthur M.; Prochaska, J. Xavier; Neeleman, Marcel; Mendez, Alexander J.

2012-08-01

We present chemical abundance measurements for 47 damped Lyα (DLA) systems, 30 at z > 4, observed with the Echellette Spectrograph and Imager and the High Resolution Echelle Spectrometer on the Keck telescopes. H I column densities of the DLAs are measured with Voigt profile fits to the Lyα profiles, and we find an increased number of false DLA identifications with Sloan Digital Sky Survey at z > 4 due to the increased density of the Lyα forest. Ionic column densities are determined using the apparent optical depth method, and we combine our new metallicity measurements with 195 from previous surveys to determine the evolution of the cosmic metallicity of neutral gas. We find the metallicity of DLAs decreases with increasing redshift, improving the significance of the trend and extending it to higher redshifts, with a linear fit of -0.22 ± 0.03 dex per unit redshift from z = 0.09-5.06. The metallicity "floor" of ≈1/600 solar continues out to z ~ 5, despite our sensitivity for finding DLAs with much lower metallicities. However, this floor is not statistically different from a steep tail to the distribution. We also find that the intrinsic scatter of metallicity among DLAs of ~0.5 dex continues out to z ~ 5. In addition, the metallicity distribution and the α/Fe ratios of z > 2 DLAs are consistent with being drawn from the same parent population with those of halo stars. It is therefore possible that the halo stars in the Milky Way formed out of gas that commonly exhibits DLA absorption at z > 2.

Echelle Data Reduction Cookbook

NASA Astrophysics Data System (ADS)

Clayton, Martin

This document is the first version of the Starlink Echelle Data Reduction Cookbook. It contains scripts and procedures developed by regular or heavy users of the existing software packages. These scripts are generally of two types; templates which readers may be able to modify to suit their particular needs and utilities which carry out a particular common task and can probably be used `off-the-shelf'. In the nature of this subject the recipes given are quite strongly tied to the software packages, rather than being science-data led. The major part of this document is divided into two sections dealing with scripts to be used with IRAF and with Starlink software (SUN/1).

Photoelectrochemical fabrication of spectroscopic diffraction gratings, phase 2

NASA Technical Reports Server (NTRS)

Rauh, R. David; Carrabba, Michael M.; Li, Jianguo; Cartland, Robert F.; Hachey, John P.; Mathew, Sam

1990-01-01

This program was directed toward the production of Echelle diffraction gratings by a light-driven, electrochemical etching technique (photoelectrochemical etching). Etching is carried out in single crystal materials, and the differential rate of etching of the different crystallographic planes used to define the groove profiles. Etching of V-groove profiles was first discovered by us during the first phase of this project, which was initially conceived as a general exploration of photoelectrochemical etching techniques for grating fabrication. This highly controllable V-groove etching process was considered to be of high significance for producing low pitch Echelles, and provided the basis for a more extensive Phase 2 investigation.

VizieR Online Data Catalog: Double-peaked narrow lines in AGN. II. z<0.1 (Nevin+, 2016)

NASA Astrophysics Data System (ADS)

Nevin, R.; Comerford, J.; Muller-Sanchez, F.; Barrows, R.; Cooper, M.

2017-02-01

To determine the nature of 71 Type 2 AGNs with double-peaked [OIII] emission lines in SDSS that are at z<0.1 and further characterize their properties, we observe them using two complementary follow-up methods: optical long-slit spectroscopy and Jansky Very Large Array (VLA) radio observations. We use various spectrographs with similar pixel scales (Lick Kast Spectrograph; Palomar Double Spectrograph; MMT Blue Channel Spectrograph; APO Dual Imaging Spectrograph and Keck DEep Imaging Multi-Object Spectrograph. We use a 1200 lines/mm grating for all spectrographs; see table 1. In future work, we will combine our long-slit observations with the VLA data for the full sample of 71 galaxies (O. Muller-Sanchez+ 2016, in preparation). (4 data files).

The BigBOSS spectrograph

NASA Astrophysics Data System (ADS)

Jelinsky, Patrick; Bebek, Chris; Besuner, Robert; Carton, Pierre-Henri; Edelstein, Jerry; Lampton, Michael; Levi, Michael E.; Poppett, Claire; Prieto, Eric; Schlegel, David; Sholl, Michael

2012-09-01

BigBOSS is a proposed ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with a 14,000 square degree galaxy and quasi-stellar object redshift survey. It consists of a 5,000- fiber-positioner focal plane feeding the spectrographs. The optical fibers are separated into ten 500 fiber slit heads at the entrance of ten identical spectrographs in a thermally insulated room. Each of the ten spectrographs has a spectral resolution (λ/Δλ) between 1500 and 4000 over a wavelength range from 360 - 980 nm. Each spectrograph uses two dichroic beam splitters to separate the spectrograph into three arms. It uses volume phase holographic (VPH) gratings for high efficiency and compactness. Each arm uses a 4096x4096 15 μm pixel charge coupled device (CCD) for the detector. We describe the requirements and current design of the BigBOSS spectrograph. Design trades (e.g. refractive versus reflective) and manufacturability are also discussed.

Internal motions of HII regions and giant HII regions

NASA Technical Reports Server (NTRS)

Chu, You-Hua; Kennicutt, Robert C., Jr.

1994-01-01

We report new echelle observations of the kinematics of 30 HII regions in the Large Magellanic Clouds (LMC), including the 30 Doradus giant HII region. All of the HII regions possess supersonic velocity dispersions, which can be attributed to a combination of turbulent motions and discrete velocity splitting produced by stellar winds and/or embedded supernova remnants (SNRs). The core of 30 Dor is unique, with a complex velocity structure that parallels its chaotic optical morphology. We use our calibrated echelle data to measure the physical properties and energetic requirements of these velocity structures. The most spectacular structures in 30 Dor are several fast expanding shells, which appear to be produced at least partially by SNRs.

GMTIFS: challenging optical design problems and their solutions for the GMT integral-field spectrograph

NASA Astrophysics Data System (ADS)

Hart, John; Bloxham, Gabe; Boz, Robert; Espeland, Brady; Sharp, Robert

2016-08-01

GMTIFS is a first generation instrument for the Giant Magellan Telescope (GMT). It is a combined Imager and Integral Field Spectrograph (IFS) designed to work with the Adaptive Optics (AO) Systems of the GMT. Working at the diffraction limit of the GMT and satisfying the challenging AO interface requirements and constraints results in unique optical challenges. We describe two of these challenges and how we have addressed them. The GMT has a direct feed architecture that maximizes transmission and reduces emissivity. This means that the cryostat window is tilted to reflect visual wavelengths to the external Visual Wave Front Subsystem (VWS). For a plane-parallel window, this tilt causes astigmatism in the transmitted beam that must be corrected. A corrective system using two plates, tilted and slightly wedged in opposite directions, is used. Geometry and performance of the system is described. Another challenging problem is the optical design of the anamorphic field projector. The Integral Field Unit of GMTIFS requires that a small field delivered to it be projected onto an Image Slicer at much larger scale, with the magnification in the spectral direction being twice that in the spatial direction so that the spaxels are square when referred to the sky. Output images must be coincident in the spectral and spatial projections in both the field and pupil domains. Additionally, field and pupil image locations must be independently controllable so that they can be made coincident for interchangeable units that provide a range of output field scales. A two-mirror system that satisfies these requirements is described.

The deterministic optical alignment of the HERMES spectrograph

NASA Astrophysics Data System (ADS)

Gers, Luke; Staszak, Nicholas

2014-07-01

The High Efficiency and Resolution Multi Element Spectrograph (HERMES) is a four channel, VPH-grating spectrograph fed by two 400 fiber slit assemblies whose construction and commissioning has now been completed at the Anglo Australian Telescope (AAT). The size, weight, complexity, and scheduling constraints of the system necessitated that a fully integrated, deterministic, opto-mechanical alignment system be designed into the spectrograph before it was manufactured. This paper presents the principles about which the system was assembled and aligned, including the equipment and the metrology methods employed to complete the spectrograph integration.

Slit Function Measurement of An Imaging Spectrograph Using Fourier Transform Techniques

NASA Technical Reports Server (NTRS)

Park, Hongwoo; Swimyard, Bruce; Jakobsen, Peter; Moseley, Harvey; Greenhouse, Matthew

2004-01-01

Knowledge of a spectrograph slit function is necessary to interpret the unresolved lines in an observed spectrum. A theoretical slit function can be calculated from the sizes of the entrance slit, the detector aperture when it functions as an exit slit, the dispersion characteristic of the disperser, and the point spread function of the spectrograph. A measured slit function is preferred to the theoretical one for the correct interpretation of the spectral data. In a scanning spectrometer with a single exit slit, the slit function is easily measured. In a fixed grating/or disperser spectrograph, illuminating the entrance slit with a near monochromatic light from a pre-monochrmator or a tunable laser and varying the wavelength of the incident light can measure the slit function. Even though the latter technique had been used successfully for the slit function measurements, it had been very laborious and it would be prohibitive to an imaging spectrograph or a multi-object spectrograph that has a large field of view. We explore an alternative technique that is manageable for the measurements. In the proposed technique, the imaging spectrograph is used as a detector of a Fourier transform spectrometer. This method can be applied not only to an IR spectrograph but also has a potential to a visible/UV spectrograph including a wedge filter spectrograph. This technique will require a blackbody source of known temperature and a bolometer to characterize the interferometer part of the Fourier Transform spectrometer. This pa?er will describe the alternative slit function measurement technique using a Fourier transform spectrometer.

Mauna Kea Spectrographic Explorer (MSE): a conceptual design for multi-object high resolution spectrograph

NASA Astrophysics Data System (ADS)

Zhang, Kai; Zhu, Yongtian; Hu, Zhongwen

2016-08-01

The Maunakea Spectroscopic Explorer (MSE) project will transform the CFHT 3.6m optical telescope into a 10m class dedicated multi-object spectroscopic facility, with an ability to simultaneously measure thousands of objects with a spectral resolution range spanning 2,000 to 40,000. MSE will develop two spectrographic facilities to meet the science requirements. These are respectively, the Low/Medium Resolution spectrographs (LMRS) and High Resolution spectrographs (HRS). Multi-object high resolution spectrographs with total of 1,156 fibers is a big challenge, one that has never been attempted for a 10m class telescope. To date, most spectral survey facilities work in single order low/medium resolution mode, and only a few Wide Field Spectrographs (WFS) provide a cross-dispersion high resolution mode with a limited number of orders. Nanjing Institute of Astronomical Optics and Technology (NIAOT) propose a conceptual design with the use of novel image slicer arrays and single order immersed Volume Phase Holographic (VPH) grating for the MSE multi-object high resolution spectrographs. The conceptual scheme contains six identical fiber-link spectrographs, each of which simultaneously covers three restricted bands (λ/30, λ/30, λ/15) in the optical regime, with spectral resolution of 40,000 in Blue/Visible bands (400nm / 490nm) and 20,000 in Red band (650nm). The details of the design is presented in this paper.

VLT instruments: industrial solutions for non-scientific detector systems

NASA Astrophysics Data System (ADS)

Duhoux, P.; Knudstrup, J.; Lilley, P.; Di Marcantonio, P.; Cirami, R.; Mannetta, M.

2014-07-01

Recent improvements in industrial vision technology and products together with the increasing need for high performance, cost efficient technical detectors for astronomical instrumentation have led ESO with the contribution of INAF to evaluate this trend and elaborate ad-hoc solutions which are interoperable and compatible with the evolution of VLT standards. The ESPRESSO spectrograph shall be the first instrument deploying this technology. ESO's Technical CCD (hereafter TCCD) requirements are extensive and demanding. A lightweight, low maintenance, rugged and high performance TCCD camera product or family of products is required which can operate in the extreme environmental conditions present at ESO's observatories with minimum maintenance and minimal downtime. In addition the camera solution needs to be interchangeable between different technical roles e.g. slit viewing, pupil and field stabilization, with excellent performance characteristics under a wide range of observing conditions together with ease of use for the end user. Interoperability is enhanced by conformance to recognized electrical, mechanical and software standards. Technical requirements and evaluation criteria for the TCCD solution are discussed in more detail. A software architecture has been adopted which facilitates easy integration with TCCD's from different vendors. The communication with the devices is implemented by means of dedicated adapters allowing usage of the same core framework (business logic). The preference has been given to cameras with an Ethernet interface, using standard TCP/IP based communication. While the preferred protocol is the industrial standard GigE Vision, not all vendors supply cameras with this interface, hence proprietary socket-based protocols are also acceptable with the provision of a validated Linux compliant API. A fundamental requirement of the TCCD software is that it shall allow for a seamless integration with the existing VLT software framework. ESPRESSO is a fiber-fed, cross-dispersed echelle spectrograph that will be located in the Combined-Coudé Laboratory of the VLT in the Paranal Observatory in Chile. It will be able to operate either using the light of any of the UT's or using the incoherently combined light of up to four UT's. The stabilization of the incoming beam is achieved by dedicated piezo systems controlled via active loops closed on 4 + 4 dedicated TCCD's for the stabilization of the pupil image and of the field with a frequency goal of 3 Hz on a 2nd to 3rd magnitude star. An additional 9th TCCD system shall be used as an exposure-meter. In this paper we will present the technical CCD solution for future VLT instruments.

HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4

NASA Astrophysics Data System (ADS)

Zahedy, Fakhri S.; Chen, Hsiao-Wen; Rauch, Michael; Zabludoff, Ann

2017-09-01

We report the first detection of extended neutral hydrogen (H I) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z˜ 0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at {z}{QSO}=1.676 as absorption-line probes of the ISM in the massive ({M}{star}≈ {10}11 {M}⊙ ) elliptical lens at z = 0.408, detecting gas at projected distances of d = 3.3 and 4.6 kpc on opposite sides of the lens. Using the Space Telescope Imaging Spectrograph, we obtain UV absorption spectra of the lensed QSO and identify a prominent flux discontinuity and associated absorption features matching the Lyman series transitions at z = 0.408 in both sightlines. The H I column density is log N({{H}} {{I}})=19.6{--}19.7 at both locations across the lens, comparable to what is seen in 21 cm images of nearby ellipticals. The H I gas kinematics are well-matched with the kinematics of the Fe II absorption complex revealed in ground-based echelle data, displaying a large velocity shear of ≈360 {\\text{km s}}-1 across the galaxy. We estimate an ISM Fe abundance of 0.3-0.4 solar at both locations. Including likely dust depletions increases the estimated Fe abundances to solar or supersolar, similar to those of the hot ISM and stars of nearby ellipticals. Assuming 100% covering fraction of this Fe-enriched gas, we infer a total Fe mass of {M}{cool}({Fe})˜ (5{--}8)× {10}4 {M}⊙ in the cool ISM of the massive elliptical lens, which is no more than 5% of the total Fe mass observed in the hot ISM.

SOFIA Education/Public Outreach with the Echelon Cross Echelle Spectrograph (EXES)

NASA Astrophysics Data System (ADS)

Hemenway, M. K.; Lacy, J. H.; Jaffe, D. T.; Richter, M. J.; Green, K.; Harkrider, J. L.; Lutsinger, C. L.; Noid, E.; Penn, R.; Shepherd, L.; Suder, R.; Tykoski, M. J.; Willis, M. J.

1998-12-01

The integration of science and technology is maximized in the development of a new scientific instrument for SOFIA like EXES. Many teachers with good science backgrounds have never had an experience in which they can learn first-hand about instrument development. The goal of this program is to prepare a cadre of teachers who will promote astronomy within their communities and who will be prepared eventually for a flight experience on SOFIA. This program provides grade 7-12 Central Texas (i.e., work within 100 miles of UT-Austin) teachers an opportunity to learn not only the principles of astronomy, but also the technology behind instrument development. By spreading the experience out over several years, the group may observe the development and construction of EXES through many phases. In addition to traditional laboratory exercises [e.g. the celestial sphere, optics, optical telescopes, spectroscopy, use of CCD cameras, and error analysis], there will be practice in using equipment such as an interferometer for optical alignment, drill press, mill, and lathe. Simultaneous with the teachers' growing understanding of astronomy and technology through their hands-on activities, their knowledge of scientific research - particularly in the area of infrared astronomy - will be enhanced through regular interactive talks by the co-investigators. With careful planning, several important secondary goals are achieved with this program: 1. The activities are aligned with the National Science Education Standards 2. Many of the traditional astronomy activities have been modified for use by secondary school students 3. Information on careers is developed through activities which emphasize the team-work necessary to build and operate EXES 4. Professional links are forged between the EXES team and the teachers

The Abundance of C2H4 in the Circumstellar Envelope of IRC+10216.

PubMed

Fonfría, J P; Hinkle, K H; Cernicharo, J; Richter, M J; Agúndez, M; Wallace, L

2017-02-01

High spectral resolution mid-IR observations of ethylene (C 2 H 4 ) towards the AGB star IRC+10216 were obtained using the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). Eighty ro-vibrational lines from the 10.5 µ m vibrational mode ν 7 with J ≲ 30 were detected in absorption. The observed lines are divided into two groups with rotational temperatures of 105 and 400 K (warm and hot lines). The warm lines peak at ≃ -14 km s -1 with respect to the systemic velocity, suggesting that they are mostly formed outwards from ≃ 20 R ⋆ . The hot lines are centered at -10 km s -1 indicating that they come from a shell between 10 and 20 R ⋆ . 35% of the observed lines are unblended and can be fitted with a code developed to model the emission of a spherically symmetric circumstellar envelope. The analysis of several scenarios reveal that the C 2 H 4 abundance relative to H 2 in the range 5 - 20 R ⋆ is 6.9 × 10 -8 in average and it could be as high as 1.1 × 10 -7 . Beyond 20 R ⋆ , it is 8.2 × 10 -8 . The total column density is (6.5 ± 3.0) × 10 15 cm -2 . C 2 H 4 is found to be rotationally under local thermodynamical equilibrium (LTE) and vibrationally out of LTE. One of the scenarios that best reproduce the observations suggests that up to 25% of the C 2 H 4 molecules at 20 R ⋆ could condense onto dust grains. This possible depletion would not influence significantly the gas acceleration although it could play a role in the surface chemistry on the dust grains.

A Planetary System around the nearby M Dwarf GJ 667C with At Least One Super-Earth in Its Habitable Zone

NASA Astrophysics Data System (ADS)

Anglada-Escudé, Guillem; Arriagada, Pamela; Vogt, Steven S.; Rivera, Eugenio J.; Butler, R. Paul; Crane, Jeffrey D.; Shectman, Stephen A.; Thompson, Ian B.; Minniti, Dante; Haghighipour, Nader; Carter, Brad D.; Tinney, C. G.; Wittenmyer, Robert A.; Bailey, Jeremy A.; O'Toole, Simon J.; Jones, Hugh R. A.; Jenkins, James S.

2012-05-01

We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the European Southern Observatory public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/Planet Finder Spectrograph and Keck/High Resolution Echelle Spectrometer spectrometers reveals three additional signals beyond the previously reported 7.2 day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (period ~10 years). The 28 day signal implies a planet candidate with a minimum mass of 4.5 M ⊕ orbiting well within the canonical definition of the star's liquid water habitable zone (HZ), that is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition, and interior dynamics. The 75 day signal is less certain, being significantly affected by aliasing interactions among a potential 91 day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal-poor compared to the Sun. The presence of a super-Earth in the HZ of a metal-poor M dwarf in a triple star system supports the evidence that such worlds should be ubiquitous in the Galaxy.

Profiles of spectral lines, magnetic fields, and thermodynamical conditions in the X17.2/4B solar flare of 2003 October 28

NASA Astrophysics Data System (ADS)

Lozitsky, V. G.; Baranovsky, E. A.; Lozitska, N. I.; Tarashchuk, V. P.

2018-06-01

We analyse the peak phase of the exclusively powerful solar proton flare of 2003 October 28,which had originated in the active region NOAA 0486. For studying the physical conditions in the flare, we used 12 spectral lines including lines from Fe I, Fe II, and the H α, H β, H γ, H δ lines observed with the Echelle spectrograph of the horizontal solar telescope of the Astronomical Observatory of the Taras Shevchenko National University of Kyiv. We found that this flare had a unique Balmer decrement, with the record ratio I (H β)/I(H α) = 1.68 of H β and H α intensities, which is unprecedented for all flares observed. In a place outside sunspots, the effective magnetic field measured by splitting `center of gravity' I ± V profiles was found within the range of 0-200 G in the middle photosphere, till 1200 G in the upper photosphere and the temperature minimum zone and up to 500 G in the chromosphere. The essential broadening of the Fe I 5250.2 line versus the Fe I 5247.1 one was found indicating the presence of a strong (800-1100 G) `turbulent' field in the middle photosphere. A semi-empirical model of the chromosphere constructed using the algorithms in PANDORA code has an interesting peculiarity, namely three discrete layers with an increased concentration and/or temperature, including a very dense and thin layer with the following parameters: the concentration of hydrogen nH = 1018 cm3, the thickness Δh = 3-5 km, and a height of h ≈ 1200 km above the photosphere.

An empirically derived three-dimensional Laplace resonance in the Gliese 876 planetary system

NASA Astrophysics Data System (ADS)

Nelson, Benjamin E.; Robertson, Paul M.; Payne, Matthew J.; Pritchard, Seth M.; Deck, Katherine M.; Ford, Eric B.; Wright, Jason T.; Isaacson, Howard T.

2016-01-01

We report constraints on the three-dimensional orbital architecture for all four planets known to orbit the nearby M dwarf Gliese 876 based solely on Doppler measurements and demanding long-term orbital stability. Our data set incorporates publicly available radial velocities taken with the ELODIE and CORALIE spectrographs, High Accuracy Radial velocity Planet Searcher (HARPS), and Keck HIgh Resolution Echelle Spectrometer (HIRES) as well as previously unpublished HIRES velocities. We first quantitatively assess the validity of the planets thought to orbit GJ 876 by computing the Bayes factors for a variety of different coplanar models using an importance sampling algorithm. We find that a four-planet model is preferred over a three-planet model. Next, we apply a Newtonian Markov chain Monte Carlo algorithm to perform a Bayesian analysis of the planet masses and orbits using an N-body model in three-dimensional space. Based on the radial velocities alone, we find that a 99 per cent credible interval provides upper limits on the mutual inclinations for the three resonant planets (Φcb < 6.20° for the {c} and {b} pair and Φbe < 28.5° for the {b} and {e} pair). Subsequent dynamical integrations of our posterior sample find that the GJ 876 planets must be roughly coplanar (Φcb < 2.60° and Φbe < 7.87°, suggesting that the amount of planet-planet scattering in the system has been low. We investigate the distribution of the respective resonant arguments of each planet pair and find that at least one argument for each planet pair and the Laplace argument librate. The libration amplitudes in our three-dimensional orbital model support the idea of the outer three planets having undergone significant past disc migration.

Texes Observations of M Supergiants: Dynamics and Thermodynamics of Wind Acceleration

NASA Astrophysics Data System (ADS)

Harper, Graham M.; Richter, Matthew J.; Ryde, Nils; Brown, Alexander; Brown, Joanna; Greathouse, Thomas K.; Strong, Shadrian

2009-08-01

We have detected [Fe II] 17.94 μm and 24.52 μm emission from a sample of M supergiants (μ Cep, α Sco, α Ori, CE Tau, AD Per, and α Her) using the Texas Echelon Cross Echelle Spectrograph on NASA's Infrared Telescope Facility. These low opacity emission lines are resolved at R sime 50, 000 and provide new diagnostics of the dynamics and thermodynamics of the stellar wind acceleration zone. The [Fe II] lines, from the first excited term (a 4 F), are sensitive to the warm plasma where energy is deposited into the extended atmosphere to form the chromosphere and wind outflow. These diagnostics complement previous Kuiper Airborne Observatory and Infrared Space Observatory observations which were sensitive to the cooler and more extended circumstellar envelopes. The turbulent velocities of V turb sime 12-13 km s-1 observed in the [Fe II] a 4 F forbidden lines are found to be a common property of our sample, and are less than that derived from the hotter chromospheric C II] 2325 Å lines observed in α Ori, where V turb sime 17-19 km s-1. For the first time, we have dynamically resolved the motions of the dominant cool atmospheric component discovered in α Ori from multiwavelength radio interferometry by Lim et al. Surprisingly, the emission centroids are quite Gaussian and at rest with respect to the M supergiants. These constraints combined with model calculations of the infrared emission line fluxes for α Ori imply that the warm material has a low outflow velocity and is located close to the star. We have also detected narrow [Fe I] 24.04 μm emission that confirms Fe II is the dominant ionization state in α Ori's extended atmosphere.

Automated spectroscopic abundances of A and F-type stars using echelle spectrographs. II. Abundances of 140 A-F stars from ELODIE

NASA Astrophysics Data System (ADS)

Erspamer, D.; North, P.

2003-02-01

Using the method presented in Erspamer & North (\\cite{erspamer}, hereafter Paper I), detailed abundances of 140 stars are presented. The uncertainties characteristic of this method are presented and discussed. In particular, we show that for a S/N ratio higher than 200, the method is applicable to stars with a rotational velocity as high as 200 km s-1. There is no correlation between abundances and Vsin i, except a spurious one for Sr, Sc and Na which we explain by the small number of lines of these elements combined with a locally biased continuum. Metallic giants (Hauck \\cite{hauck}) show larger abundances than normal giants for at least 8 elements: Al, Ca, Ti, Cr, Mn, Fe, Ni and Ba. The anticorrelation for Na, Mg, Si, Ca, Fe and Ni with Vsin i suggested by Varenne & Monier (\\cite{varenne99}) is not confirmed. The predictions of the Montréal models (e.g. Richard et al. \\cite{richard01}) are not fulfilled in general. However, a correlation between left [(Fe)/(H)right ] and log g is found for stars of 1.8 to 2.0 M_sun. Various possible causes are discussed, but the physical reality of this correlation seems inescapable. Based on observations collected at the 1.93 m telescope at the Observatoire de Haute-Provence (St-Michel l'Observatoire, France) and CORALIE. Based on observations collected at the Swiss 1.2 m Leonard Euler telescopes at the European Southern Observatory (La Silla, Chile). Tables 5 and 6 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u.strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/398/1121

The R-process Alliance: First Release from the Southern Search for R-process-enhanced Stars in the Galactic Halo

NASA Astrophysics Data System (ADS)

Hansen, Terese T.; Holmbeck, Erika M.; Beers, Timothy C.; Placco, Vinicius M.; Roederer, Ian U.; Frebel, Anna; Sakari, Charli M.; Simon, Joshua D.; Thompson, Ian B.

2018-05-01

The recent detection of a binary neutron star merger and the clear evidence of the decay of radioactive material observed in this event have, after 60 years of effort, provided an astrophysical site for the rapid neutron-capture (r-) process which is responsible for the production of the heaviest elements in our universe. However, observations of metal-poor stars with highly enhanced r-process elements have revealed abundance patterns suggesting that multiple sites may be involved. To address this issue, and to advance our understanding of the r-process, we have initiated an extensive search for bright (V < 13.5), very metal-poor ([Fe/H] < ‑2) stars in the Milky Way halo exhibiting strongly enhanced r-process signatures. This paper presents the first sample collected in the southern hemisphere using the echelle spectrograph on du Pont 2.5 m telescope at Las Campanas Observatory. We have observed and analyzed 107 stars with ‑3.13 < [Fe/H] < ‑0.79. Of those, 12 stars are strongly enhanced in heavy r-process elements (r-II), 42 stars show moderate enhancements of heavy r-process material (r-I), and 20 stars exhibit low abundances of the heavy r-process elements and higher abundances of the light r-process elements relative to the heavy ones (limited-r). This search is more successful at finding r-process-enhanced stars compared to previous searches, primarily due to a refined target selection procedure that focuses on red giants. This paper includes data gathered with the 2.5 m du Pont telescope located at Las Campanas Observatory, Chile.

Quasar 2175 Å dust absorbers - I. Metallicity, depletion pattern and kinematics

NASA Astrophysics Data System (ADS)

Ma, Jingzhe; Ge, Jian; Zhao, Yinan; Prochaska, J. Xavier; Zhang, Shaohua; Ji, Tuo; Schneider, Donald P.

2017-12-01

We present 13 new 2175 Å dust absorbers at zabs = 1.0-2.2 towards background quasars from the Sloan Digital Sky Survey. These absorbers are examined in detail using data from the Echelle Spectrograph and Imager (ESI) on the Keck II telescope. Many low-ionization lines including Fe II, Zn II, Mg II, Si II, Al II, Ni II, Mn II, Cr II, Ti II and Ca II are present in the same absorber that gives rise to the 2175 Å bump. The relative metal abundances (with respect to Zn) demonstrate that the depletion patterns of our 2175 Å dust absorbers resemble that of the Milky Way clouds although some are disc-like and some are halo-like. The 2175 Å dust absorbers have significantly higher depletion levels compared to literature damped Lyman α absorbers (DLAs) and sub-DLAs. The dust depletion level indicator [Fe/Zn] tends to anticorrelate with bump strengths. The velocity profiles from the Keck/ESI spectra also provide kinematical information on the dust absorbers. The dust absorbers are found to have multiple velocity components with velocity widths extending from ∼100 to ∼600 km s-1, which are larger than those of most DLAs and sub-DLAs. Assuming the velocity width is a reliable tracer of stellar mass, the host galaxies of 2175 Å dust absorbers are expected to be more massive than DLA/sub-DLA hosts. Not all of the 2175 Å dust absorbers are intervening systems towards background quasars. The absorbers towards quasars J1006+1538 and J1047+3423 are proximate systems that could be associated with the quasar itself or the host galaxy.

Search for Exoplanets around Northern Circumpolar Stars. II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Byeong-Cheol; Jeong, Gwanghui; Han, Inwoo

2017-07-20

We present the detection of long-period RV variations in HD 36384, HD 52030, and HD 208742 by using the high-resolution, fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) for the precise radial velocity (RV) survey of about 200 northern circumpolar stars. Analyses of RV data, chromospheric activity indicators, and bisector variations spanning about five years suggest that the RV variations are compatible with planet or brown dwarf companions in Keplerian motion. However, HD 36384 shows photometric variations with a period very close to that of RV variations as well as amplitude variations in the weighted wavelet Z-transform (WWZ) analysis, which argues thatmore » the RV variations in HD 36384 are from the stellar pulsations. Assuming that the companion hypothesis is correct, HD 52030 hosts a companion with minimum mass 13.3 M {sub Jup} orbiting in 484 days at a distance of 1.2 au. HD 208742 hosts a companion of 14.0 M {sub Jup} at 1.5 au with a period of 602 days. All stars are located at the asymptotic giant branch (AGB) stage on the H–R diagram after undergoing the helium flash and leaving the giant clump.With stellar radii of 53.0 R {sub ⊙} and 57.2 R {sub ⊙} for HD 52030 and HD 208742, respectively, these stars may be the largest yet, in terms of stellar radius, found to host substellar companions. However, given possible RV amplitude variations and the fact that these are highly evolved stars, the planet hypothesis is not yet certain.« less

AN INDEPENDENT MEASUREMENT OF THE INCIDENCE OF Mg II ABSORBERS ALONG GAMMA-RAY BURST SIGHT LINES: THE END OF THE MYSTERY?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cucchiara, A.; Prochaska, J. X.; Zhu, G.

2013-08-20

In 2006, Prochter et al. reported a statistically significant enhancement of very strong Mg II absorption systems intervening the sight lines to gamma-ray bursts (GRBs) relative to the incidence of such absorption along quasar sight lines. This counterintuitive result has inspired a diverse set of astrophysical explanations (e.g., dust, gravitational lensing) but none of these has obviously resolved the puzzle. Using the largest set of GRB afterglow spectra available, we reexamine the purported enhancement. In an independent sample of GRB spectra with a survey path three times larger than Prochter et al., we measure the incidence per unit redshift ofmore » {>=}1 A rest-frame equivalent width Mg II absorbers at z Almost-Equal-To 1 to be l(z) = 0.18 {+-} 0.06. This is fully consistent with current estimates for the incidence of such absorbers along quasar sight lines. Therefore, we do not confirm the original enhancement and suggest those results suffered from a statistical fluke. Signatures of the original result do remain in our full sample (l(z) shows an Almost-Equal-To 1.5 enhancement over l(z){sub QSO}), but the statistical significance now lies at Almost-Equal-To 90% c.l. Restricting our analysis to the subset of high-resolution spectra of GRB afterglows (which overlaps substantially with Prochter et al.), we still reproduce a statistically significant enhancement of Mg II absorption. The reason for this excess, if real, is still unclear since there is no connection between the rapid afterglow follow-up process with echelle (or echellette) spectrographs and the detectability of strong Mg II doublets. Only a larger sample of such high-resolution data will shed some light on this matter.« less

Absolute Dimensions and Evolutionary Status of the Semi-detached Algol W Ursae Minoris

NASA Astrophysics Data System (ADS)

Park, Jang-Ho; Hong, Kyeongsoo; Koo, Jae-Rim; Lee, Jae Woo; Kim, Chun-Hwey

2018-03-01

Double-lined eclipsing binaries allow accurate and direct determination of fundamental parameters such as mass and radius for each component, and they provide important constraints on the stellar structure and evolution models. In this study, we aim to determine a unique set of binary parameters for the Algol system W UMi and to examine its evolutionary status. New high-resolution time-series spectroscopic observations were carried out during 14 nights from 2008 April to 2011 March, and a total of 37 spectra were obtained using the Bohyunsan Optical Echelle Spectrograph. We measured the radial velocities (RVs) for both components, and the effective temperature of the primary star was found to be T eff,1 = 9310 ± 90 K by a comparison of the observed spectra and the Kurucz models. The physical parameters of W UMi were derived by an analysis of our RV data together with the multi-band light curves of Devinney et al. The individual masses, radii, and luminosities of both components are M 1 = 3.68 ± 0.10 M ⊙ and M 2 = 1.47 ± 0.04 M ⊙, R 1 = 3.88 ± 0.03 R ⊙ and R 2 = 3.13 ± 0.03 R ⊙, and L 1 = 102 ± 1 L ⊙ and L 2 = 7.3 ± 0.1 L ⊙, respectively. A comparison of these parameters with theoretical stellar models showed that the primary component lies in the main-sequence band, while the less massive secondary is noticeably evolved. The results indicate that the initially more massive star became the present secondary by losing most of its own mass via mass transfer to the companion (present primary).

Constraints On The Distribution Of Methane In Uranus' Atmosphere

NASA Astrophysics Data System (ADS)

Norwood, James; Chanover, N.; Hammel, H.

2006-09-01

As Uranus approaches its December 2007 equinox, we are treated to a unique opportunity to observe an atmosphere that has become much more active since Voyager's flyby near solstice, as well as a favorable viewing geometry in which the lines of constant latitude as seen fom Earth are straight and parallel. Here we present analysis of newly obtained spectra of Uranus' visible and near-infrared methane bands. In September 2006, near-IR spectra of Uranus were taken using SpeX (R 1000-2000) at NASA's Infrared Telescope Facility (IRTF). We use these data to constrain the vertical abundance profile of methane, the most abundant component of the Uranian atmosphere following H2 and He. A spectral synthesis program developed at NASA/Goddard Space Flight Center for the analysis of infrared spectroscopy was employed to determine the properties of a model atmosphere that best reproduce the methane features observed. These spectra are supplemented by high-resolution visible spectra taken with the ARC echelle spectrograph (R = 37,500) on the 3.5-m telescope at Apache Point Observatory in Sunspot, New Mexico, in October 2005 and August 2006. The new activity seen in Uranus' atmosphere near equinox, such as the appearance of new cloud features (Hammel et al., Icarus 175, 284-288 [2005]), indicates that the Uranian atmosphere undergoes dramatic seasonal changes. The possibility of changes in the methane profile that have occurred since previous observations (Fink and Larson, ApJ 233, 1021-1040 [1979] and others) is discussed. We also take advantage of the unique observing geometry near Uranian equinox to examine any variations in the methane distribution with latitude. This work was supported by NASA through award number NNG05GB86G.

GLOBULAR CLUSTER ABUNDANCES FROM HIGH-RESOLUTION, INTEGRATED-LIGHT SPECTROSCOPY. III. THE LARGE MAGELLANIC CLOUD: Fe AND AGES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colucci, Janet E.; Bernstein, Rebecca A.; Cameron, Scott A.

2011-07-01

In this paper, we refine our method for the abundance analysis of high-resolution spectroscopy of the integrated light of unresolved globular clusters (GCs). This method was previously demonstrated for the analysis of old (>10 Gyr) Milky Way (MW) GCs. Here, we extend the technique to young clusters using a training set of nine GCs in the Large Magellanic Cloud. Depending on the signal-to-noise ratio of the data, we use 20-100 Fe lines per cluster to successfully constrain the ages of old clusters to within a {approx}5 Gyr range, the ages of {approx}2 Gyr clusters to a 1-2 Gyr range, andmore » the ages of the youngest clusters (0.05-1 Gyr) to a {approx}200 Myr range. We also demonstrate that we can measure [Fe/H] in clusters with any age less than 12 Gyr with similar or only slightly larger uncertainties (0.1-0.25 dex) than those obtained for old MW GCs (0.1 dex); the slightly larger uncertainties are due to the rapid evolution in stellar populations at these ages. In this paper, we present only Fe abundances and ages. In the next paper in this series, we present our complete analysis of {approx}20 elements for which we are able to measure abundances. For several of the clusters in this sample, there are no high-resolution abundances in the literature from individual member stars; our results are the first detailed chemical abundances available. The spectra used in this paper were obtained at Las Campanas with the echelle on the du Pont Telescope and with the MIKE spectrograph on the Magellan Clay Telescope.« less

Beyond 3 Au from the Sun: the Hypervolatiles CH4, C2H6, and CO in the Distant Comet C2006 W3 (Christensen)

NASA Technical Reports Server (NTRS)

Bonev, Boncho P.; Villanueva, Geronimo L.; Disanti, Michael A.; Boehnhardt, Hermann; Lippi, Manuela; Gibb, Erika L.; Paganini, Lucas; Mumma, Michael J.

2017-01-01

Comet C/2006 W3 (Christensen) remained outside a heliocentric distance (Rh) of 3.1 au throughout its apparition, but it presented an exceptional opportunity to directly sense a suite of molecules released from its nucleus. The Cryogenic Infrared Echelle Spectrograph at ESO-VLT detected infrared emissions from the three hypervolatiles (CO, CH4, and C2H6) that have the lowest sublimation temperatures among species that are commonly studied in comets by remote sensing. Even at Rh 3.25 au, the production rate of each molecule exceeded those measured for the same species in a number of other comets, although these comets were observed much closer to the Sun. Detections of CO at Rh = 3.25, 4.03, and 4.73 au constrained its post-perihelion decrease in production rate, which most likely dominated the outgassing. At 3.25 au, our measured abundances scaled as CO/CH4/C2H6 approx. = 100/4.4/2.1. The C2H6/CH4 ratio falls within the range of previously studied comets at Rh < 2 au, while CO/CH4 is comparatively high and similar to in situ measurements from Rosetta at approx.10 km from the nucleus of 67P/Churyumov-Gerasimenko conducted at a very similar Rh (3.15 au). The independent detections of H2O (Herschel Space Observatory) and CO (this work) imply a coma abundance H2O/CO approx. = 20% in C/2006 W3 near Rh = 5 au. All these measurements are of high value for constraining models of nucleus sublimation (plausibly CO-driven) beyond Rh = 3au, where molecular detections in comets are still especially sparse.

Measuring FeO variation using astronomical spectroscopic observations

NASA Astrophysics Data System (ADS)

Unterguggenberger, Stefanie; Noll, Stefan; Feng, Wuhu; Plane, John M. C.; Kausch, Wolfgang; Kimeswenger, Stefan; Jones, Amy; Moehler, Sabine

2017-03-01

Airglow emission lines of OH, O2, O and Na are commonly used to probe the MLT (mesosphere-lower thermosphere) region of the atmosphere. Furthermore, molecules like electronically excited NO, NiO and FeO emit a (pseudo-) continuum. These continua are harder to investigate than atomic emission lines. So far, limb-sounding from space and a small number of ground-based low-to-medium resolution spectra have been used to measure FeO emission in the MLT. In this study the medium-to-high resolution echelle spectrograph X-shooter at the Very Large Telescope (VLT) in the Chilean Atacama Desert (24°37' S, 70°24' W; 2635 m) is used to study the FeO pseudo-continuum in the range from 0.5 to 0.72 µm based on 3662 spectra. Variations of the FeO spectrum itself, as well as the diurnal and seasonal behaviour of the FeO and Na emission intensities, are reported. These airglow emissions are linked by their common origin, meteoric ablation, and they share O3 as a common reactant. Major differences are found in the main emission peak of the FeO airglow spectrum between 0.58 and 0.61 µm, compared with a theoretical spectrum. The FeO and Na airglow intensities exhibit a similar nocturnal variation and a semi-annual seasonal variation with equinoctial maxima. This is satisfactorily reproduced by a whole atmosphere chemistry climate model, if the quantum yields for the reactions of Fe and Na with O3 are 13 ± 3 and 11 ± 2 % respectively. However, a comparison between the modelled O3 in the upper mesosphere and measurements of O3 made with the SABER satellite instrument suggests that these quantum yields may be a factor of ˜ 2 smaller.

The Abundance of C2H4 in the Circumstellar Envelope of IRC+10216

PubMed Central

Fonfría, J. P.; Hinkle, K. H.; Cernicharo, J.; Richter, M. J.; Agúndez, M.

2017-01-01

High spectral resolution mid-IR observations of ethylene (C2H4) towards the AGB star IRC+10216 were obtained using the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). Eighty ro-vibrational lines from the 10.5 µm vibrational mode ν7 with J ≲ 30 were detected in absorption. The observed lines are divided into two groups with rotational temperatures of 105 and 400 K (warm and hot lines). The warm lines peak at ≃ −14 km s−1 with respect to the systemic velocity, suggesting that they are mostly formed outwards from ≃ 20R⋆. The hot lines are centered at −10 km s−1 indicating that they come from a shell between 10 and 20R⋆. 35% of the observed lines are unblended and can be fitted with a code developed to model the emission of a spherically symmetric circumstellar envelope. The analysis of several scenarios reveal that the C2H4 abundance relative to H2 in the range 5 − 20R⋆ is 6.9 × 10−8 in average and it could be as high as 1.1 × 10−7. Beyond 20R⋆, it is 8.2 × 10−8. The total column density is (6.5 ± 3.0) × 1015 cm−2. C2H4 is found to be rotationally under local thermodynamical equilibrium (LTE) and vibrationally out of LTE. One of the scenarios that best reproduce the observations suggests that up to 25% of the C2H4 molecules at 20R⋆ could condense onto dust grains. This possible depletion would not influence significantly the gas acceleration although it could play a role in the surface chemistry on the dust grains. PMID:28184097

A green observatory in the Chilean Atacama desert

NASA Astrophysics Data System (ADS)

Ramolla, Michael; Westhues, Christian; Hackstein, Moritz; Haas, Martin; Hodapp, Klaus; Lemke, Roland; Barr Domínguez, Angie; Chini, Rolf; Murphy, Miguel

2016-08-01

Since 2007, the Ruhr-Universität Bochum (RUB) in Germany and Universidad Católica del Norte (UCN) in Chile jointly operate the Universitätssternwarte der Ruhr-Universität Bochum (USB), which is located in direct neighborhood of the future E-ELT of ESO. It is the only observatory powered exclusively by solar panels and wind turbines. Excess power is stored in batteries that allow uninterrupted operation even in windless nights. The scientific equipment consists of three robotic optical telescopes with apertures ranging from 15 cm (RoBoTT) over 25 cm (BESTII) to 40 cm (BMT) and one 80 cm (IRIS) infra-red telescope. The optical telescopes are equipped with Johnson and Sloan broad band filters together with a large number of narrow and intermediate bands. In the infrared, J,H and K filters are available, accompanied by several narrow bands near the K band wavelength. The second Nasmyth focus in the 80 cm telescope feeds a high resolution echelle spectrograph similar to the FEROS instrument of ESO. This variety of instruments has evolved from different collaborations, i.e. with the University of Hawaii (IfA) in the USA, which provided the near-infrared-camera of the IRIS telescope, or with the Deutsches Zentrum für Luft- und Raumfahrt (DLR) in Germany, which provided the BESTII telescope. The highly automatized processes on all telescopes enable a single person to run the whole facility, providing the high cost efficiency required for an university observatory. The excellent site conditions allow projects that require daily observations of astronomical objects over epochs of several months or years. Here we report on such studies of young stellar objects from the Bochum Galactic Disk Survey, the multiplicity of stars, quasar variability or the hunt for exo-planets.

The Chemical Abundances of Stars in the Halo (CASH) Project. II. A Sample of 14 Extremely Metal-poor Stars

NASA Astrophysics Data System (ADS)

Hollek, Julie K.; Frebel, Anna; Roederer, Ian U.; Sneden, Christopher; Shetrone, Matthew; Beers, Timothy C.; Kang, Sung-ju; Thom, Christopher

2011-11-01

We present a comprehensive abundance analysis of 20 elements for 16 new low-metallicity stars from the Chemical Abundances of Stars in the Halo (CASH) project. The abundances have been derived from both Hobby-Eberly Telescope High Resolution Spectrograph snapshot spectra (R ~15, 000) and corresponding high-resolution (R ~35, 000) Magellan Inamori Kyocera Echelle spectra. The stars span a metallicity range from [Fe/H] from -2.9 to -3.9, including four new stars with [Fe/H] < -3.7. We find four stars to be carbon-enhanced metal-poor (CEMP) stars, confirming the trend of increasing [C/Fe] abundance ratios with decreasing metallicity. Two of these objects can be classified as CEMP-no stars, adding to the growing number of these objects at [Fe/H]< - 3. We also find four neutron-capture-enhanced stars in the sample, one of which has [Eu/Fe] of 0.8 with clear r-process signatures. These pilot sample stars are the most metal-poor ([Fe/H] <~ -3.0) of the brightest stars included in CASH and are used to calibrate a newly developed, automated stellar parameter and abundance determination pipeline. This code will be used for the entire ~500 star CASH snapshot sample. We find that the pipeline results are statistically identical for snapshot spectra when compared to a traditional, manual analysis from a high-resolution spectrum. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen. Based on observations gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

Advanced structural design for precision radial velocity instruments

NASA Astrophysics Data System (ADS)

Baldwin, Dan; Szentgyorgyi, Andrew; Barnes, Stuart; Bean, Jacob; Ben-Ami, Sagi; Brennan, Patricia; Budynkiewicz, Jamie; Chun, Moo-Young; Conroy, Charlie; Crane, Jeffrey D.; Epps, Harland; Evans, Ian; Evans, Janet; Foster, Jeff; Frebel, Anna; Gauron, Thomas; Guzman, Dani; Hare, Tyson; Jang, Bi-Ho; Jang, Jeong-Gyun; Jordan, Andres; Kim, Jihun; Kim, Kang-Min; Mendes de Oliveira, Claudia; Lopez-Morales, Mercedes; McCracken, Kenneth; McMuldroch, Stuart; Miller, Joseph; Mueller, Mark; Oh, Jae Sok; Ordway, Mark; Park, Byeong-Gon; Park, Chan; Park, Sung-Joon; Paxson, Charles; Phillips, David; Plummer, David; Podgorski, William; Seifahrt, Andreas; Stark, Daniel; Steiner, Joao; Uomoto, Alan; Walsworth, Ronald; Yu, Young-Sam

2016-07-01

The GMT-Consortium Large Earth Finder (G-CLEF) is an echelle spectrograph with precision radial velocity (PRV) capability that will be a first light instrument for the Giant Magellan Telescope (GMT). G-CLEF has a PRV precision goal of 40 cm/sec (10 cm/s for multiple measurements) to enable detection of Earth-like exoplanets in the habitable zones of sun-like stars1. This precision is a primary driver of G-CLEF's structural design. Extreme stability is necessary to minimize image motions at the CCD detectors. Minute changes in temperature, pressure, and acceleration environments cause structural deformations, inducing image motions which degrade PRV precision. The instrument's structural design will ensure that the PRV goal is achieved under the environments G-CLEF will be subjected to as installed on the GMT azimuth platform, including: Millikelvin (0.001 °K) thermal soaks and gradients 10 millibar changes in ambient pressure Changes in acceleration due to instrument tip/tilt and telescope slewing Carbon fiber/cyanate composite was selected for the optical bench structure in order to meet performance goals. Low coefficient of thermal expansion (CTE) and high stiffness-to-weight are key features of the composite optical bench design. Manufacturability and serviceability of the instrument are also drivers of the design. In this paper, we discuss analyses leading to technical choices made to minimize G-CLEF's sensitivity to changing environments. Finite element analysis (FEA) and image motion sensitivity studies were conducted to determine PRV performance under operational environments. We discuss the design of the optical bench structure to optimize stiffness-to-weight and minimize deformations due to inertial and pressure effects. We also discuss quasi-kinematic mounting of optical elements and assemblies, and optimization of these to ensure minimal image motion under thermal, pressure, and inertial loads expected during PRV observations.

Measuring NH3 and other molecular abundance profiles from 5 microns ground-based spectroscopy in support of JUNO investigations

NASA Astrophysics Data System (ADS)

Blain, Doriann; Fouchet, Thierry; Greathouse, Thomas K.; Bézard, Bruno; Encrenaz, Therese; Lacy, John H.; Drossart, Pierre

2017-10-01

We report on results of an observational campaign to support the Juno mission. At the beginning of 2016, using TEXES (Texas Echelon cross-dispersed Echelle Spectrograph), mounted on the NASA Infrared Telescope Facility (IRTF), we obtained data cubes of Jupiter in the 1930--1943 cm-1 and 2135--2153 cm-1 spectral ranges (around 5 μm), which probe the atmosphere in the 1--4 bar region, with a spectral resolution of ≈0.3 cm-1 (R≈7000) and an angular resolution of ≈1.5''.This dataset is analyzed by a code that combines a line-by-line radiative transfer model with a non-linear optimal estimation inversion method. The inversion retrieves the abundance profiles of NH3 and PH3, which are the main conbtributors at these wavelengths, as well as the cloud transmittance. This retrieval is performed over more than one thousand pixels of our data cubes, producing effective maps of the disk, where all the major belts are visible (NEB, SEB, NTB, STB, NNTB and SSTB).We will present notably our retrieved NH3 abundance maps which can be compared with the unexpected latitudinal distribution observed by Juno's MWR (Bolton et al., 2017 and Li et al. 2017), as well as our other species retrieved abundance maps and discuss on their significance for the understanding of Jupiter's atmospheric dynamics.References:Bolton, S., et al. (2017), Jupiter’s interior and deep atmosphere: The first close polar pass with the Juno spacecraft, Science, doi:10.1126/science.aal2108, in press.Li, C., A. P. Ingersoll, S. Ewald, F. Oyafuso, and M. Janssen (2017), Jupiter’s global ammonia distribution from inversion of Juno Microwave Radiometer observations, Geophys. Res. Lett., doi:10.1002/2017GL073159, in press.

Qatar-2: A K Dwarf Orbited by a Transiting Hot Jupiter and a Longer-Period Massive Planet

NASA Astrophysics Data System (ADS)

Bryan, Marta; Alsubai, K. A.; Latham, D. W.; Quinn, S. N.; Collier Cameron, A.; Carter, J. A.; Buchave, L. A.

2012-01-01

We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a K dwarf in a circular orbit with a short period, Pb = 1.34 days. Differential photometry and model fitting of transit data from both KeplerCam and LCOGT yielded light curve parameters Rp/Rs, a/Rs, u1, u2, and i that were optimized using the Markov Chain Monte Carlo technique. Radial velocity measurements from the Tillinghast Reflector Echelle Spectrograph of Qatar-2 over a span of 153 days provided a mass estimate for Qatar-2b, with velocity residuals from the orbital solution that pointed to the presence of a third body in the system. The light curve parameter a/Rs and spectroscopic values for effective temperature and metallicity were used in conjunction with stellar models to estimate the mass and radius of Qatar-2, leading to a mass and radius for Qatar-2b of MP = 2.54 MJ and RP = 1.14 RJ, respectively. Next we used the Systemic Console to explore possible orbital solutions for the outer companion, Qatar-2c. Plausible solutions have periods slightly less than a year and a mass of several MJ. However, further observations are needed to determine a reliable orbit for Qatar-2c. Qatar-2 is only the fourth example in the short but growing list of systems with a transiting hot Jupiter and an outer companion. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar.

A Differential Chemical Element Analysis of the Metal-poor Globular Cluster NGC 6397

NASA Astrophysics Data System (ADS)

Koch, Andreas; McWilliam, Andrew

2011-08-01

We present chemical abundances in three red giants and two turnoff (TO) stars in the metal-poor Galactic globular cluster (GC) NGC 6397 based on spectroscopy obtained with the Magellan Inamori Kyocera Echelle high-resolution spectrograph on the Magellan 6.5 m Clay telescope. Our results are based on a line-by-line differential abundance analysis relative to the well-studied red giant Arcturus and the Galactic halo field star Hip 66815. At a mean of -2.10 ± 0.02 (stat.) ±0.07 (sys.), the differential iron abundance is in good agreement with other studies in the literature based on gf-values. As in previous differential works we find a distinct departure from ionization equilibrium in that the abundances of Fe I and Fe II differ by ~0.1 dex, with opposite signs for the red giant branch (RGB) and TO stars. The α-element ratios are enhanced to 0.4 (RGB) and 0.3 dex (TO), respectively, and we also confirm strong variations in the O, Na, and Al/Fe abundance ratios. Accordingly, the light-element abundance patterns in one of the red giants can be attributed to pollution by an early generation of massive Type II supernovae. TO and RGB abundances are not significantly different, with the possible exception of Mg and Ti, which are, however, amplified by the patterns in one TO star additionally belonging to this early generation of GC stars. We discuss interrelations of these light elements as a function of the GC metallicity. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

LRS2: A New Integral Field Spectrograph for the HET

NASA Astrophysics Data System (ADS)

Tuttle, Sarah E.; Hill, Gary J.; Chonis, Taylor S.; Tonnesen, Stephanie

2016-01-01

Here we present LRS2 (Low Resolution Spectrograph) and highlight early science opportunities with the newly upgraded Hobby Eberly telescope (HET). LRS2 is a four-channel optical wavelength (370nm - 1micron) spectrograph based on two VIRUS unit spectrographs. This fiber-fed integral field spectrograph covers a 12" x 6" field of view, switched between the two units (one blue, and one red) at R~2000. We highlight design elements, including the fundamental modification to grisms (from VPH gratings in VIRUS) to access the higher resolution. We discuss early science opportunities, including investigating nearby "blue-bulge" spiral galaxies and their anomalous star formation distribution.

Eta Carinae: At the Crossroads of becoming a Supernova

NASA Technical Reports Server (NTRS)

Gull, Theodore

2007-01-01

Since the 1840's, when Eta Carinae's visual magnitude rivaled Sirius, the brightest star in the night sky, astronomers have wondered what major event took place. Today with the Hubble Space Telescope Imaging Spectrograph, with CHANDRA X-ray spectroscopy and the Very Large Telescope spectrographs and interferometers, we have learned that over 12 solar masses of material was ejected at 500 to 700 km/s into interstellar space. This ejecta is quite different from the normal interstellar medium. It is rich in nitrogen, poor in oxygen and carbon. The dust properties are quite peculiar and many metals such as vanadium, strontium, cadmium are seen in both absorption against the central source, plus a number of molecules. The chemical and dust formation is likely dominated by nitrogen as we see H_2, CH, CH+, OH, NH, HCl and NH-3, but no CO. Other metals and molecules are being searched out in the FUSE, HST/STIS, VLT/UVES and VLT/CRIRES spectra. I will describe what we know about the massive binary stellar system, how it changes every 5.54 year in UV and X-ray output and how the massive ejecta responds in this astrophysical laboratory.

UNEXPECTED SERIES OF REGULAR FREQUENCY SPACING OF δ SCUTI STARS IN THE NON-ASYMPTOTIC REGIME. I. THE METHODOLOGY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paparó, M.; Benkő, J. M.; Hareter, M.

A sequence search method was developed to search the regular frequency spacing in δ Scuti stars through visual inspection and an algorithmic search. We searched for sequences of quasi-equally spaced frequencies, containing at least four members per sequence, in 90 δ Scuti stars observed by CoRoT . We found an unexpectedly large number of independent series of regular frequency spacing in 77 δ Scuti stars (from one to eight sequences) in the non-asymptotic regime. We introduce the sequence search method presenting the sequences and echelle diagram of CoRoT 102675756 and the structure of the algorithmic search. Four sequences (echelle ridges)more » were found in the 5–21 d{sup −1} region where the pairs of the sequences are shifted (between 0.5 and 0.59 d{sup −1}) by twice the value of the estimated rotational splitting frequency (0.269 d{sup −1}). The general conclusions for the whole sample are also presented in this paper. The statistics of the spacings derived by the sequence search method, by FT (Fourier transform of the frequencies), and the statistics of the shifts are also compared. In many stars more than one almost equally valid spacing appeared. The model frequencies of FG Vir and their rotationally split components were used to formulate the possible explanation that one spacing is the large separation while the other is the sum of the large separation and the rotational frequency. In CoRoT 102675756, the two spacings (2.249 and 1.977 d{sup −1}) are in better agreement with the sum of a possible 1.710 d{sup −1} large separation and two or one times, respectively, the value of the rotational frequency.« less

Optical Design And Performance Of A Dual-Grating, Direct-Reading Spectrograph For Spectrochemical Analyses

NASA Astrophysics Data System (ADS)

Steinhaus, David W.; Kline, John V.; Bieniewski, Thomas M.; Dow, Grove S.; Apel, Charles T.

1980-11-01

An all-mirror optical system is used to direct the light from a variety of spectroscopic sources to two 2-m spectrographs that are placed on either side of a sturdy vertical mounting plate. The gratings were chosen so that the first spectrograph covers the ultraviolet spectral region, and the second spectrograph covers the ultraviolet, visible, and near-infrared regions. With the over 2.5 m of focal curves, each ultraviolet line is available at more than one place. Thus, problems with close lines can be overcome. The signals from a possible maximum of 256 photoelectric detectors go to a small computer for reading and calculation of the element abundances. To our knowledge, no other direct-reading spectrograph has more than about 100 fixed detectors. With an inductively-coupled-plasma source, our calibration curves, and detection limits, are similar to those of other workers using a direct-reading spectrograph.

An Analysis of Eruptions Detected by the LMSAL Eruption Patrol

NASA Astrophysics Data System (ADS)

Hurlburt, N. E.; Higgins, P. A.; Jaffey, S.

2014-12-01

Observations of the solar atmosphere reveals a wide range of real and apparent motions, from small scale jets and spicules to global-scale coronal mass ejections. Identifying and characterizing these motions are essential to advance our understanding the drivers of space weather. Automated and visual identifications are used in identifying CMEs. To date, the precursors to these — eruptions near the solar surface — have been identified primarily by visual inspection. Here we report on an analysis of the eruptions detected by the Eruption Patrol, a data mining module designed to automatically identify eruptions from data collected by Solar Dynamics Observatory's Atmospheric Imaging Assembly (SDO/AIA). We describe the module and use it both to explore relations with other solar events recorded in the Heliophysics Event Knowledgebase and to identify and access data collected by the Interface Region Imaging Spectrograph (IRIS) and Solar Optical Telescope (SOT) on Hinode for further analysis.

Design and realization of the real-time spectrograph controller for LAMOST based on FPGA

NASA Astrophysics Data System (ADS)

Wang, Jianing; Wu, Liyan; Zeng, Yizhong; Dai, Songxin; Hu, Zhongwen; Zhu, Yongtian; Wang, Lei; Wu, Zhen; Chen, Yi

2008-08-01

A large Schmitt reflector telescope, Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST), is being built in China, which has effective aperture of 4 meters and can observe the spectra of as many as 4000 objects simultaneously. To fit such a large amount of observational objects, the dispersion part is composed of a set of 16 multipurpose fiber-fed double-beam Schmidt spectrographs, of which each has about ten of moveable components realtimely accommodated and manipulated by a controller. An industrial Ethernet network connects those 16 spectrograph controllers. The light from stars is fed to the entrance slits of the spectrographs with optical fibers. In this paper, we mainly introduce the design and realization of our real-time controller for the spectrograph, our design using the technique of System On Programmable Chip (SOPC) based on Field Programmable Gate Array (FPGA) and then realizing the control of the spectrographs through NIOSII Soft Core Embedded Processor. We seal the stepper motor controller as intellectual property (IP) cores and reuse it, greatly simplifying the design process and then shortening the development time. Under the embedded operating system μC/OS-II, a multi-tasks control program has been well written to realize the real-time control of the moveable parts of the spectrographs. At present, a number of such controllers have been applied in the spectrograph of LAMOST.

New infrared spectrograph for the investigation of the mesopause region

NASA Astrophysics Data System (ADS)

Koltovskoi, I. I.; Ammosov, P. P.; Gavrilyeva, G. A.; Ammosova, A. M.; Sivseva, V. I.

2017-11-01

A new infrared spectrograph with high temporal resolution for observation of OH band (3-1) emission dynamics is described. For the automated work of the spectrograph, special software was created. Remote control over the device is also configured.

Observations of Superwinds in Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Marlowe, A. T.; Heckman, T. M.; Wyse, R.; Schommer, R.

1993-12-01

Dwarf galaxies are important in developing our understanding of the formation and evolution of galaxies, and of the structure in the universe. The concept of supernova-driven mass outflows is a vital ingredient in theories of the structure and evolution of dwarfs galaxies. We have begun a detailed multi-waveband search for outflows in starbursting dwarf galaxies, and have obtained Fabry-Perot images and Echelle spectra of 20 nearby actively-star-forming dwarf galaxies. In about half the sample, the Fabry-Perot Hα images show loops and filaments with sizes of one to a few kpc. The Echelle spectra taken through the loops and filaments show kinematics consistent with expanding bubble-like structures. We describe these data, and present seven dwarfs in our sample that have the strongest evidence of outflows.

Whistle register: a preliminary investigation by HSDI visualization and acoustics on female cases

NASA Astrophysics Data System (ADS)

Di Corcia, Antonio; Fussi, Franco

2012-02-01

In this study we investigated laryngeal behaviors involved during vocal production of highest female vocal ranges in Flute in M3 Register, in Whistle Register and in a newly formulated by us, Hiss Register. Observations were carried with stroboscopy and High Speed Digital Imaging and with spectrographic and psycho-acoustic analysis by means of a software system having a wide spectral range (0-20.000 Hz). Results indicate that at the highest pitch vocal folds vibration is absent or significantly reduced, glottic contact is incomplete. These acoustic form of extreme pitch levels comprised intra-harmonic noise and overtones within 10 to 18 kHz range.

Goodman High Throughput Spectrograph | SOAR

Science.gov Websites

SPARTAN Near-IR Camera Ohio State Infrared Imager/Spectrograph (OSIRIS) - NO LONGER AVAILABLE SOAR 320-850 nm wavelength range. The paper describing the instrument is Clemens et al. (2004) Applying for IRAF. Publishing results based on Goodman data?: ADS link to 2004 SPIE Goodman Spectrograph paper

Compact high-resolution spectrographs for large and extremely large telescopes: using the diffraction limit

NASA Astrophysics Data System (ADS)

Robertson, J. Gordon; Bland-Hawthorn, Joss

2012-09-01

As telescopes get larger, the size of a seeing-limited spectrograph for a given resolving power becomes larger also, and for ELTs the size will be so great that high resolution instruments of simple design will be infeasible. Solutions include adaptive optics (but not providing full correction for short wavelengths) or image slicers (which give feasible but still large instruments). Here we develop the solution proposed by Bland-Hawthorn and Horton: the use of diffraction-limited spectrographs which are compact even for high resolving power. Their use is made possible by the photonic lantern, which splits a multi-mode optical fiber into a number of single-mode fibers. We describe preliminary designs for such spectrographs, at a resolving power of R ~ 50,000. While they are small and use relatively simple optics, the challenges are to accommodate the longest possible fiber slit (hence maximum number of single-mode fibers in one spectrograph) and to accept the beam from each fiber at a focal ratio considerably faster than for most spectrograph collimators, while maintaining diffraction-limited imaging quality. It is possible to obtain excellent performance despite these challenges. We also briefly consider the number of such spectrographs required, which can be reduced by full or partial adaptive optics correction, and/or moving towards longer wavelengths.

PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression

NASA Astrophysics Data System (ADS)

Horton, Anthony; Ellis, Simon; Lawrence, Jon; Bland-Hawthorn, Joss

2012-09-01

Fibre Bragg grating (FBG) OH suppression is capable of greatly reducing the bright sky background seen by near infrared spectrographs. By filtering out the airglow emission lines at high resolution before the light enters the spectrograph this technique prevents scattering from the emission lines into interline regions, thereby reducing the background at all wavelengths. In order to take full advantage of this sky background reduction the spectrograph must have very low instrumental backgrounds so that it remains sky noise limited. Both simulations and real world experience with the prototype GNOSIS system show that existing spectrographs, designed for higher sky background levels, will be unable to fully exploit the sky background reduction. We therefore propose PRAXIS, a spectrograph optimised specifically for this purpose. The PRAXIS concept is a fibre fed, fully cryogenic, fixed format spectrograph for the J and H-bands. Dark current will be minimised by using the best of the latest generation of NIR detectors while thermal backgrounds will be reduced by the use of a cryogenic fibre slit. Optimised spectral formats and the use of high throughput volume phase holographic gratings will further enhance sensitivity. Our proposal is for a modular system, incorporating exchangeable fore-optics units, integral field units and OH suppression units, to allow PRAXIS to operate as a visitor instrument on any large telescope and enable new developments in FBG OH suppression to be incorporated as they become available. As a high performance fibre fed spectrograph PRAXIS could also serve as a testbed for other astrophotonic technologies.

The problem of scattering in fibre-fed VPH spectrographs and possible solutions

NASA Astrophysics Data System (ADS)

Ellis, S. C.; Saunders, Will; Betters, Chris; Croom, Scott

2014-07-01

All spectrographs unavoidably scatter light. Scattering in the spectral direction is problematic for sky subtraction, since atmospheric spectral lines are blurred. Scattering in the spatial direction is problematic for fibre fed spectrographs, since it limits how closely fibres can be packed together. We investigate the nature of this scattering and show that the scattering wings have both a Lorentzian component, and a shallower (1/r) component. We investigate the causes of this from a theoretical perspective, and argue that for the spectral PSF the Lorentzian wings are in part due to the profile of the illumination of the pupil of the spectrograph onto the diffraction grating, whereas the shallower component is from bulk scattering. We then investigate ways to mitigate the diffractive scattering by apodising the pupil. In the ideal case of a Gaussian apodised pupil, the scattering can be significantly improved. Finally we look at realistic models of the spectrograph pupils of fibre fed spectrographs with a centrally obstructed telescope, and show that it is possible to apodise the pupil through non-telecentric injection into the fibre.

Visible camera cryostat design and performance for the SuMIRe Prime Focus Spectrograph (PFS)

NASA Astrophysics Data System (ADS)

Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Hope, Stephen C.; Madec, Fabrice; Gabriel, Jean-Francois; Loomis, Craig; Le fur, Arnaud; Dohlen, Kjetil; Le Mignant, David; Barkhouser, Robert; Carr, Michael; Hart, Murdock; Tamura, Naoyuki; Shimono, Atsushi; Takato, Naruhisa

2016-08-01

We describe the design and performance of the SuMIRe Prime Focus Spectrograph (PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering wavelength ranges 380 nm - 640 nm, 640 nm - 955 nm, and 955 nm - 1.26 um, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. The cameras are very large, having a clear aperture of 300 mm at the entrance window, and a mass of 280 kg. In this paper we describe the design of the visible camera cryostats and discuss various aspects of cryostat performance.

Goddard High Resolution Spectrograph Observations of Variability in the RS Canum Venaticorum System V711 Tauri (HR 1099)

NASA Technical Reports Server (NTRS)

Dempsey, Robert C.; Neff, James E.; Thorpe, Marjorie J.; Linsky, Jeffrey L.; Brown, Alexander; Cutispoto, Giuseppe; Rodono, Marcello

1996-01-01

Goddard High Resolution Spectrograph (GHRS) observations of the RS CVn-type binary V711 Tau (Kl IV+G5 IV) were obtained at several phases over two consecutive stellar orbital cycles in order to study ultraviolet emission-line profile and flux variability. Spectra cover the Mg II h and k lines, C IV doublet, and Si IV region, as well as the density-sensitive lines of C III] (1909 A) and Si III] (1892 A). IUE spectra, Extreme Ultra Violet (EUV) data, and Ultraviolet, Blue, Visual (UBV) photometry were obtained contemporaneously with the GHRS data. Variable extended wings were detected in the Mg II lines. We discuss the Mg II line profile variability using various Gaussian emission profile models. No rotational modulation of the line profiles was observed, but there were several large flares. These flares produced enhanced emission in the extended line wings, radial velocity shifts, and asymmetries in some line profiles. Nearly continuous flaring for more than 24 hr, as indicated in the IUE data, represents the most energetic and long-lived chromospheric and transition region flare ever observed with a total energy much greater than 5 x 10(exp 35) ergs. The C III] to Si III] line ratio is used to estimate the plasma density during the flares.

COS2025: Extending the Lifetime of the FUV channel of the Cosmic Origins Spectrograph to 2025

NASA Astrophysics Data System (ADS)

Rafelski, Marc; De Rosa, Gisella; Fischer, William J.; Fix, Mees; Fox, Andrew; Indriolo, Nick; James, Bethan; Magness, Camellia; Oliveira, Cristina M.; Penton, Steven V.; Plesha, Rachel; Roman-Duval, Julia; Sahnow, David J.; Sankrit, Ravi; Snyder, Elaine M.; Taylor, Joanna M.; White, James

2018-01-01

The Hubble Space Telescope's Cosmic Origins Spectrograph (COS) Far-Ultraviolet (FUV) microchannel plate detector's efficiency at converting incoming photons into detectable events decreases with usage. This depletion of the detector's gain (i.e. gain sag) results in unusable regions of the COS/FUV detector. In order to mitigate this gain sag, a number of strategies have been employed over the past 8 years of operations, ranging from moving to different lifetime positions, to managing the high voltage to extract a smaller amount of charge, to re-distributing the cenwave usage so that Ly-alpha does not produce a gain-sag hole in a given location. We are now at a point where none of the strategies above will, without any other changes, allow us to continue operating the COS/FUV detector to 2025. To address this a new COS2025 policy was developed, with the goal of retaining full science capability of COS/FUV to 2025. We present an overview of the COS2025 policy, which places restrictions on the G130M cenwaves allowed at Lifetime Position 4 (LP4). We also present a tool which allows users to visualize the COS/FUV wavelength ranges to help users prepare their proposals in the light of the restrictions on the G130M cenwaves.

CARMENES in SPIE 2014. Building a fibre link for CARMENES

NASA Astrophysics Data System (ADS)

Stürmer, J.; Stahl, O.; Schwab, C.; Seifert, W.; Quirrenbach, A.; Amado, P. J.; Ribas, I.; Reiners, A.; Caballero, J. A.

2014-07-01

Optical fibres have successfully been used to couple high-resolution spectrographs to telescopes for many years. As they allow the instrument to be placed in a stable and isolated location, they decouple the spectrograph from environmental influences. Fibres also provide a substantial increase in stability of the input illumination of the spectrograph, which makes them a key optical element of the two high-resolution spectrographs of CARMENES. The optical properties of appropriate fibres are investigated, especially their scrambling and focal ratio degradation (FRD) behaviour. In the laboratory the output illumination of various fibres is characterized and different methods to increase the scrambling of the fibre link are tested and compared. In particular, a combination of fibres with different core shapes shows a very good scrambling performance. The near-field (NF) shows an extremely low sensitivity to the exact coupling conditions of the fibre. However, small changes in the far-field (FF) can still be seen. Related optical simulations of the stability performance of the two spectrographs are presented. The simulations focus on the influence of the non-perfect illumination stabilization in the far-field of the fibre on the radial velocity stability of the spectrographs. We use ZEMAX models of the spectrographs to simulate how the barycentres of the spots move depending on the FF illumination pattern and therefore how the radial velocity is affected by a variation of the spectrograph illumination. This method allows to establish a quantitative link between the results of the measurements of the optical properties of fibres on the one hand and the radial velocity precision on the other. The results provide a strong indication that 1ms?1 precision can be reached using a circular-octagonal fibre link even without the use of an optical double scrambler, which has successfully been used in other high-resolution spectrographs. Given the typical throughput of an optical double scrambler of about 75% to 85 %, our solution allows for a substantially higher throughput of the system.

VizieR Online Data Catalog: PS1 z>5.6 quasars follow-up (Banados+, 2016)

NASA Astrophysics Data System (ADS)

Banados, E.; Venemans, B. P.; Decarli, R.; Farina, E. P.; Mazzucchelli, C.; Walter, F.; Fan, X.; Stern, D.; Schlafly, E.; Chambers, K. C.; Rix, H.-W.; Jiang, L.; McGreer, I.; Simcoe, R.; Wang, F.; Yang, J.; Morganson, E.; De Rosa, G.; Greiner, J.; Balokovic, M.; Burgett, W. S.; Cooper, T.; Draper, P. W.; Flewelling, H.; Hodapp, K. W.; Jun, H. D.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E. A.; Metcalfe, N.; Miller, D.; Schindler, J.-T.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.; Yang, Q.

2017-01-01

The photometric follow-up observations were carried out over different observing runs and different instruments. We obtained optical and near-infrared images with the MPG 2.2m/GROND, New Technology Telescope (NTT)/EFOSC2, NTT/SofI, Calar Alto (CAHA) 3.5m/Omega2000, CAHA 2.2m/CAFOS21, MMT/SWIRC), and du Pont/Retrocam; see Table 1 for details of the observations and filters used. A spectroscopic campaign was carried out using several instruments at different telescopes: EFOSC2 at the NTT telescope in La Silla, the Focal Reducer / Low-Dispersion Spectrograph 2 (FORS2) at the Very Large Telescope (VLT), the Folded-Port Infrared Echellette (FIRE) spectrometer and the Low-Dispersion Survey Spectrograph (LDSS3) at the Baade and Clay Telescopes at Las Campanas Observatory, the Low-Resolution Imaging Spectrometer (LRIS) at the Keck I 10m Telescope on Mauna Kea, the Double Spectrograph (DBSP) on the 200 inch (5m) Hale Telescope at Palomar Observatory (P200), the Red-Channel Spectrograph on the 6.5m MMT Telescope, the Cassegrain TWIN Spectrograph at the 3.5m Calar Alto Telescope (CAHA 3.5m), and the Multi-object Double Spectrograph (MODS) and LUCI spectrograph at the Large Binocular Telescope (LBT). The details of the spectroscopic observations of the PS1-discovered quasars are shown in Table 5. (10 data files).

Effect of Acoustic Spectrographic Instruction on Production of English /i/ and /I/ by Spanish Pre-Service English Teachers

ERIC Educational Resources Information Center

Quintana-Lara, Marcela

2014-01-01

This study investigates the effects of Acoustic Spectrographic Instruction on the production of the English phonological contrast /i/ and / I /. Acoustic Spectrographic Instruction is based on the assumption that physical representations of speech sounds and spectrography allow learners to objectively see and modify those non-accurate features in…

Sky Subtraction with Fiber-Fed Spectrograph

NASA Astrophysics Data System (ADS)

Rodrigues, Myriam

2017-09-01

"Historically, fiber-fed spectrographs had been deemed inadequate for the observation of faint targets, mainly because of the difficulty to achieve high accuracy on the sky subtraction. The impossibility to sample the sky in the immediate vicinity of the target in fiber instruments has led to a commonly held view that a multi-object fibre spectrograph cannot achieve an accurate sky subtraction under 1% contrary to their slit counterpart. The next generation of multi-objects spectrograph at the VLT (MOONS) and the planed MOS for the E-ELT (MOSAIC) are fiber-fed instruments, and are aimed to observed targets fainter than the sky continuum level. In this talk, I will present the state-of-art on sky subtraction strategies and data reduction algorithm specifically developed for fiber-fed spectrographs. I will also present the main results of an observational campaign to better characterise the sky spatial and temporal variations ( in particular the continuum and faint sky lines)."

The FIREBall fiber-fed UV spectrograph

NASA Astrophysics Data System (ADS)

Tuttle, Sarah E.; Schiminovich, David; Milliard, Bruno; Grange, Robert; Martin, D. Christopher; Rahman, Shahinur; Deharveng, Jean-Michel; McLean, Ryan; Tajiri, Gordon; Matuszewski, M.

2008-07-01

FIREBall (Faint Intergalactic Redshifted Emission Balloon) had a successful first engineering flight in July of 2007 from Palestine, Texas. Here we detail the design and construction of the spectrograph. FIREBall consists of a 1m telescope coupled to a fiber-fed ultraviolet spectrograph flown on a short duration balloon. The spectrograph is designed to map hydrogen and metal line emission from the intergalactic medium at several redshifts below z=1, exploiting a small window in atmospheric oxygen absorption at balloon altitudes. The instrument is a wide-field IFU fed by almost 400 fibers. The Offner mount spectrograph is designed to be sensitive in the 195-215nm window accessible at our altitudes of 35-40km. We are able to observe Lyα, as well as OVI and CIV doublets, from 0.3 < z < 0.9. Observations of UV bright B stars and background measurements allow characterization of throughput for the entire system and will inform future flights.

A Student Assembled Spectrograph with a CCD Detector to Assist with Students' Understanding of Spectrometry

ERIC Educational Resources Information Center

Grove, T. T.; Masters, M. F.

2007-01-01

To help students develop an understanding of the proper use and function of spectrographs and monochromators we describe a student-assembled spectrograph using a "webcam" detector. The apparatus also works well as a low-cost demonstration, helping students make connections between an atomic spectrum observed by eye and a plot of the relative…

X-ray spectrographic determination of cesium and rubidium

USGS Publications Warehouse

Axelrod, J.M.; Adler, I.

1957-01-01

An x-ray spectrographic method for the determination of rubidium and cesium was developed, using the internal-standard method and a four-channel flat-crystal spectrograph. The sensitivity is within 0.1% for cesia and 0.02% for rubidia; the precision is within 10% of the amount present. Results agree well with those obtained by flame photometry and by radio-activation.

Scientific Design of a High Contrast Integral Field Spectrograph for the Subaru Telescope

NASA Technical Reports Server (NTRS)

McElwain, Michael W.

2012-01-01

Ground based telescopes equipped with adaptive optics systems and specialized science cameras are now capable of directly detecting extrasolar planets. We present the scientific design for a high contrast integral field spectrograph for the Subaru Telescope. This lenslet based integral field spectrograph will be implemented into the new extreme adaptive optics system at Subaru, called SCExAO.

Thirty-Meter Telescope: A Technical Study of the InfraRed Multiobject Spectrograph

NASA Astrophysics Data System (ADS)

U, Vivian; Dekany, R.; Mobasher, B.

2013-01-01

The InfraRed Multiobject Spectrograph (IRMS) is an adaptive optics (AO)-fed, reconfigurable near-infrared multi-object spectrograph and imager on the Thirty Meter Telescope (TMT). Its design is based on the MOSFIRE spectrograph currently operating on the Keck Observatory. As one of the first three first-light instruments on the TMT, IRMS is in a mini-conceptual design phase. Here we motivate the science goals of the instrument and present the anticipated sensitivity estimates based on the combination of MOSFIRE with the AO system NFIRAOS on TMT. An assessment of the IRMS on-instrument wavefront sensor performance and vignetting issue will also be discussed.

VizieR Online Data Catalog: The ELM survey. VII. 15 new ELM white dwarf cand. (Brown+, 2016)

NASA Astrophysics Data System (ADS)

Brown, W. R.; Gianninas, A.; Kilic, M.; Kenyon, S. J.; Allende Prieto, C.

2016-05-01

We present observations of 15 new extremely low-mass white dwarf (ELM WD) candidates. Ten objects are selected by color for our targeted spectroscopic ELM Survey program as described in Brown et al. (2012ApJ...744..142B). Five objects come from follow-up spectroscopy of the completed Hypervelocity Star survey. We acquire spectra for the 15 ELM WD candidates using the Blue Channel spectrograph on the 6.5m MMT telescope. We configured the Blue Channel spectrograph to obtain 3650-4500Å spectral coverage with 1.0Å spectral resolution. We acquire additional spectra for 5 objects using the KOSMOS spectrograph on the Kitt Peak National Observatory 4m Mayall telescope on program numbers 2014B-0119 and 2015A-0082. We configured the KOSMOS spectrograph to obtain 3500-6200Å spectral coverage with 2.0Å spectral resolution. We also acquire spectra for objects with g<17mag using the FAST spectrograph on the Fred Lawrence Whipple Observatory 1.5m Tillinghast telescope. We configured the FAST spectrograph to obtain 3500-5500Å spectral coverage with 1.7Å spectral resolution. (3 data files).

High performance Si immersion gratings patterned with electron beam lithography

NASA Astrophysics Data System (ADS)

Gully-Santiago, Michael A.; Jaffe, Daniel T.; Brooks, Cynthia B.; Wilson, Daniel W.; Muller, Richard E.

2014-07-01

Infrared spectrographs employing silicon immersion gratings can be significantly more compact than spectro- graphs using front-surface gratings. The Si gratings can also offer continuous wavelength coverage at high spectral resolution. The grooves in Si gratings are made with semiconductor lithography techniques, to date almost entirely using contact mask photolithography. Planned near-infrared astronomical spectrographs require either finer groove pitches or higher positional accuracy than standard UV contact mask photolithography can reach. A collaboration between the University of Texas at Austin Silicon Diffractive Optics Group and the Jet Propulsion Laboratory Microdevices Laboratory has experimented with direct writing silicon immersion grating grooves with electron beam lithography. The patterning process involves depositing positive e-beam resist on 1 to 30 mm thick, 100 mm diameter monolithic crystalline silicon substrates. We then use the facility JEOL 9300FS e-beam writer at JPL to produce the linear pattern that defines the gratings. There are three key challenges to produce high-performance e-beam written silicon immersion gratings. (1) E- beam field and subfield stitching boundaries cause periodic cross-hatch structures along the grating grooves. The structures manifest themselves as spectral and spatial dimension ghosts in the diffraction limited point spread function (PSF) of the diffraction grating. In this paper, we show that the effects of e-beam field boundaries must be mitigated. We have significantly reduced ghost power with only minor increases in write time by using four or more field sizes of less than 500 μm. (2) The finite e-beam stage drift and run-out error cause large-scale structure in the wavefront error. We deal with this problem by applying a mark detection loop to check for and correct out minuscule stage drifts. We measure the level and direction of stage drift and show that mark detection reduces peak-to-valley wavefront error by a factor of 5. (3) The serial write process for typical gratings yields write times of about 24 hours- this makes prototyping costly. We discuss work with negative e-beam resist to reduce the fill factor of exposure, and therefore limit the exposure time. We also discuss the tradeoffs of long write-time serial write processes like e-beam with UV photomask lithography. We show the results of experiments on small pattern size prototypes on silicon wafers. Current prototypes now exceed 30 dB of suppression on spectral and spatial dimension ghosts compared to monochromatic spectral purity measurements of the backside of Si echelle gratings in reflection at 632 nm. We perform interferometry at 632 nm in reflection with a 25 mm circular beam on a grating with a blaze angle of 71.6°. The measured wavefront error is 0.09 waves peak to valley.

Discovery of starspots on Vega. First spectroscopic detection of surface structures on a normal A-type star

NASA Astrophysics Data System (ADS)

Böhm, T.; Holschneider, M.; Lignières, F.; Petit, P.; Rainer, M.; Paletou, F.; Wade, G.; Alecian, E.; Carfantan, H.; Blazère, A.; Mirouh, G. M.

2015-05-01

Context. The theoretically studied impact of rapid rotation on stellar evolution needs to be compared with these results of high-resolution spectroscopy-velocimetry observations. Early-type stars present a perfect laboratory for these studies. The prototype A0 star Vega has been extensively monitored in recent years in spectropolarimetry. A weak surface magnetic field was detected, implying that there might be a (still undetected) structured surface. First indications of the presence of small amplitude stellar radial velocity variations have been reported recently, but the confirmation and in-depth study with the highly stabilized spectrograph SOPHIE/OHP was required. Aims: The goal of this article is to present a thorough analysis of the line profile variations and associated estimators in the early-type standard star Vega (A0) in order to reveal potential activity tracers, exoplanet companions, and stellar oscillations. Methods: Vega was monitored in quasi-continuous high-resolution echelle spectroscopy with the highly stabilized velocimeter SOPHIE/OHP. A total of 2588 high signal-to-noise spectra was obtained during 34.7 h on five nights (2 to 6 of August 2012) in high-resolution mode at R = 75 000 and covering the visible domain from 3895-6270 Å. For each reduced spectrum, least square deconvolved equivalent photospheric profiles were calculated with a Teff = 9500 and log g = 4.0 spectral line mask. Several methods were applied to study the dynamic behaviour of the profile variations (evolution of radial velocity, bisectors, vspan, 2D profiles, amongst others). Results: We present the discovery of a spotted stellar surface on an A-type standard star (Vega) with very faint spot amplitudes ΔF/Fc ~ 5 × 10-4. A rotational modulation of spectral lines with a period of rotation P = 0.68 d has clearly been exhibited, unambiguously confirming the results of previous spectropolarimetric studies. Most of these brightness inhomogeneities seem to be located in lower equatorial latitudes. Either a very thin convective layer can be responsible for magnetic field generation at small amplitudes, or a new mechanism has to be invoked to explain the existence of activity tracing starspots. At this stage it is difficult to disentangle a rotational from a stellar pulsational origin for the existing higher frequency periodic variations. Conclusions: This first strong evidence that standard A-type stars can show surface structures opens a new field of research and ask about a potential link with the recently discovered weak magnetic field discoveries in this category of stars. Based on observations obtained with the SOPHIE spectrograph at the 2 m OHP telescope operated by the Institut National des Sciences de l'Univers (INSU) of the Centre National de la Recherche Scientifique of France (CNRS).

Elemental abundance analyses with Complejo Astronomico El Leoncito REOSC echelle spectrograms. IV. Extensions of nine previous analyses

NASA Astrophysics Data System (ADS)

Adelman, S. J.; Pintado, O. I.

2000-02-01

Using new CASLEO echelle spectrograms, we extended our elemental abundances of the sharp-lined Mercury-Manganese stars mu Lep, 14 Hya, kappa Cnc, HR 4487, HR 4817, 28 Her, and HR 7245, the closely related star 3 Cen A, and 7 Sex an A0 V star with Population I abundances, but with Population II star space motions. The lambda lambda 4500-6200 region contains a sufficient number of lines to derive high-quality abundances of these stars. For most stars, the new spectra provide additional lines for the analyses which improve their quality as well as help fill in the periodic table. Table~5 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or via http://cdsweb.u-strabg.fr/Abstract.html}

The high-resolution cross-dispersed echelle white-pupil spectrometer of the McDonald Observatory 2.7-m telescope

NASA Technical Reports Server (NTRS)

Tull, Robert G.; Macqueen, Phillip J.; Sneden, Christopher; Lambert, David L.

1995-01-01

A new high-resolution cross-dispersed echelle spectrometer has been installed at the coude focus of the McDonald Observatory 2.7-m telescope. Its primary goal was simultaneously to gather spectra over as much of the spectral range 3400 A to 1 micrometer as practical, at a resolution R identical with lambda/Delta lambda which approximately = 60,000 with signal-to-noise ratio of approximately 100 for stars down to magnitude 11, using 1-h exposures. In the instrument as built, two exposures are all that are needed to cover the full range. Featuring a white-pupil design, fused silica prism cross disperser, and folded Schmidt camera with a Tektronix 2048x2048 CCD used at either of two foci, it has been in regularly scheduled operation since 1992 April. Design details and performance are described.

Fundamental constants and high-resolution spectroscopy

NASA Astrophysics Data System (ADS)

Bonifacio, P.; Rahmani, H.; Whitmore, J. B.; Wendt, M.; Centurion, M.; Molaro, P.; Srianand, R.; Murphy, M. T.; Petitjean, P.; Agafonova, I. I.; D'Odorico, S.; Evans, T. M.; Levshakov, S. A.; Lopez, S.; Martins, C. J. A. P.; Reimers, D.; Vladilo, G.

2014-01-01

Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, α, and the proton-to-electron mass ratio, μ = m_p/m_e, as measured in remote regions of the Universe to their value today on Earth. In recent years, some evidence has emerged of small temporal and also spatial variations in α on cosmological scales which may reach a fractional level of ≈ 10 ppm (parts per million). We are conducting a Large Programme of observations with the Very Large Telescope's Ultraviolet and Visual Echelle Spectrograph (UVES), and are obtaining high-resolution ({R ≈ 60 000}) and high signal-to-noise ratio (S/N ≈ 100) spectra calibrated specifically to study the variations of the fundamental constants. We here provide a general overview of the Large Programme and report on the first results for these two constants, discussed in detail in Molaro et al. (2013) and Rahmani et al. (2013). A stringent bound for Δα/α is obtained for the absorber at z_abs = 1.6919 towards HE 2217-2818. The absorption profile is complex with several very narrow features, and is modeled with 32 velocity components. The relative variation in α in this system is +1.3± 2.4_stat ± 1.0_sys ppm if Al II λ 1670 Å and three Fe II transitions are used, and +1.1 ± 2.6_stat ppm in a slightly different analysis with only Fe II transitions used. This is one of the tightest bounds on α-variation from an individual absorber and reveals no evidence for variation in α at the 3-ppm precision level (1σ confidence). The expectation at this sky position of the recently-reported dipolar variation of α is (3.2-5.4)±1.7 ppm depending on dipole model used and this constraint of Δα/α at face value is not supporting this expectation but not inconsistent with it at the 3σ level. For the proton-to-electron mass ratio the analysis of the H_2 absorption lines of the z_abs ≈ 2.4018 damped Lyα system towards HE 0027-1836 provides Δμ/μ = (-7.6 ± 8.1_stat ± 6.3_sys) ppm which is also consistent with a null variation. The cross-correlation analysis between individual exposures taken over three years and comparison with almost simultaneous asteroid observations revealed the presence of a possible wavelength dependent velocity drift as well as of inter-order distortions which probably dominate the systematic error and are a significant obstacle to achieve more accurate measurements. Based on observations obtained with UVES at the the 8.2 m Kueyen ESO telescope programme L185.A-0745.

Single Mode, Extreme Precision Doppler Spectrographs

NASA Astrophysics Data System (ADS)

Schwab, Christian; Leon-Saval, Sergio G.; Betters, Christopher H.; Bland-Hawthorn, Joss; Mahadevan, Suvrath

2014-04-01

The `holy grail' of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.

Preliminary studies of laser-induced breakdown spectrometry for the determination of Ba, Cd, Cr and Pb in toys

NASA Astrophysics Data System (ADS)

Godoi, Quienly; Santos, Dario, Jr.; Nunes, Lidiane C.; Leme, Flávio O.; Rufini, Iolanda A.; Agnelli, José A. M.; Trevizan, Lilian C.; Krug, Francisco J.

2009-06-01

The performance of laser-induced breakdown spectrometry (LIBS) for the determination of Ba, Cd, Cr and Pb in toys has been evaluated by using a Nd:YAG laser operating at 1064 nm and an Echelle spectrometer with intensified charge-coupled device detector. Samples were purchased in different cities of São Paulo State market and analyzed directly without sample preparation. Laser-induced breakdown spectrometry experimental conditions (number of pulses, delay time, integration time gate and pulse energy) were optimized by using a Doehlert design. Laser-induced breakdown spectrometry signals correlated reasonably well with inductively coupled plasma optical emission spectrometry (ICP OES) concentrations after microwave-assisted acid digestion of selected samples. Thermal analysis was used for polymer identification and scanning electron microscopy to visualize differences in crater geometry of different polymers employed for toy fabrication. Results indicate that laser-induced breakdown spectrometry can be proposed as a rapid screening method for investigation of potentially toxic elements in toys. The unique application of laser-induced breakdown spectrometry for identification of contaminants in successive layers of ink and polymer is also demonstrated.

Elemental analysis of cotton by laser-induced breakdown spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schenk, Emily R.; Almirall, Jose R.

Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elementsmore » Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.« less

Improved LIBS limit of detection of Be, Mg, Si, Mn, Fe and Cu in aluminum alloy samples using a portable Echelle spectrometer with ICCD camera

NASA Astrophysics Data System (ADS)

Mohamed, Walid Tawfik Y.

2008-02-01

Laser-induced breakdown spectroscopy (LIBS) is a laser-based technique that can provide non-intrusive, qualitative and quantitative measurement of metals in various environments. LIBS uses the plasma generated by a high-energy laser beam to prepare and excite the sample in one step. In the present work, LIBS has been applied to perform elemental analysis of six trace elements simultaneously in aluminum alloy targets. The plasma is generated by focusing a pulsed Nd:YAG laser on the target in air at atmospheric pressure. LIBS limit of detection (LOD) is affected by many experimental parameters such as interferences, self-absorption, spectral overlap and matrix effect. We aimed to improve the LIBS LOD by optimizing these experimental parameters as possible. In doing so, a portable Echelle spectrometer with intensified CCD camera was used to detect the LIBS plasma emission. This advanced Echelle spectrometer provides a constant spectral resolution (CSR) of 7500 corresponding to 4 pixels FWHM over a wavelength range 200-1000 nm displayable in a single spectrum. Then, the calibration curves for iron, beryllium, magnesium, silicon, manganese and copper as minor elements were achieved with linear regression coefficients between 98-99% on average in aluminum standard sample alloys. New LOD values were achieved in the ppm range with high precision (RSD 3-8%). From the application view point, improving LIBS LOD is very important in the on-line industrial process control to follow-up multi-elements for the correct alloying in metals.

GRACES, the Gemini remote access CFHT ESPaDOnS spectrograph: initial design and testing

NASA Astrophysics Data System (ADS)

Tollestrup, Eric V.; Pazder, John; Barrick, Gregory; Martioli, Eder; Schiavon, Ricardo; Anthony, André; Halman, Mark; Veillet, Christian

2012-09-01

The Gemini Remote Access CFHT ESPaDOnS Spectrograph (GRACES) is an innovative instrumentation experiment that will demonstrate if ESPaDOnS, a bench-mounted high-resolution optical spectrograph at CFHT, can be fed by a 270-m long fiber from the Gemini-North telescope with low enough losses to remain competitive with conventional spectrographs on other 8 to 10-m telescopes. Detailed simulations have shown that GRACES should be more sensitive than the HIRES spectrograph at Keck Observatory at wavelengths longer than about 600-700 nm. This result is possible by using FPB-type of optical fibers made by Polymicro Technologies and by keeping the critical focal ratio degradation (FRD) losses to less than 10%. Laboratory tests on these FPB optical fibers are underway and show that for 36-m lengths that the FRD losses are as low as 0.8% with a repeatability of 1%. Tests are currently underway on 280-m lengths.

Reconstructive correction of aberrations in nuclear particle spectrographs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berz, M.; Joh, K.; Nolen, J.A.

A method is presented that allows the reconstruction of trajectories in particle spectrographs and the reconstructive correction of residual aberrations that otherwise limit the resolution. Using a computed or fitted high order transfer map that describes the uncorrected aberrations of the spectrograph, it is possible to calculate a map via an analytic recursion relation that allows the computation of the corrected data of interest such as reaction energy and scattering angle as well as the reconstructed trajectories in terms of position measurements in two planes near the focal plane. The technique is only limited by the accuracy of the positionmore » measurements, the incoherent spot sizes, and the accuracy of the transfer map. In practice the method can be expressed as an inversion of a nonlinear map and implemented in the differential algebraic framework. The method is applied to correct residual aberrations in the S800 spectrograph which is under construction at the National Superconducting Cyclotron Laboratory at Michigan State University and to two other high resolution spectrographs.« less

Optical design of the SuMIRe/PFS spectrograph

NASA Astrophysics Data System (ADS)

Pascal, Sandrine; Vives, Sébastien; Barkhouser, Robert; Gunn, James E.

2014-07-01

The SuMIRe Prime Focus Spectrograph (PFS), developed for the 8-m class SUBARU telescope, will consist of four identical spectrographs, each receiving 600 fibers from a 2394 fiber robotic positioner at the telescope prime focus. Each spectrograph includes three spectral channels to cover the wavelength range [0.38-1.26] um with a resolving power ranging between 2000 and 4000. A medium resolution mode is also implemented to reach a resolving power of 5000 at 0.8 um. Each spectrograph is made of 4 optical units: the entrance unit which produces three corrected collimated beams and three camera units (one per spectral channel: "blue, "red", and "NIR"). The beam is split by using two large dichroics; and in each arm, the light is dispersed by large VPH gratings (about 280x280mm). The proposed optical design was optimized to achieve the requested image quality while simplifying the manufacturing of the whole optical system. The camera design consists in an innovative Schmidt camera observing a large field-of-view (10 degrees) with a very fast beam (F/1.09). To achieve such a performance, the classical spherical mirror is replaced by a catadioptric mirror (i.e meniscus lens with a reflective surface on the rear side of the glass, like a Mangin mirror). This article focuses on the optical architecture of the PFS spectrograph and the perfornance achieved. We will first described the global optical design of the spectrograph. Then, we will focus on the Mangin-Schmidt camera design. The analysis of the optical performance and the results obtained are presented in the last section.

A New Observatory for Eastern College: A Dream Realized

NASA Astrophysics Data System (ADS)

Bradstreet, D. H.

1996-12-01

The Eastern College Observatory began as a rooftop observing deck with one Celestron 8 telescope in 1976 as the workhorse instrument of the observational astronomy lab within the core curriculum. For 20 years the observing deck served as the crude observatory, being augmented through the years by other computerized Celestron 8's and a 17.5" diameter Dobsonian with computerized setting circles. The lab consisted primarily of visual observations and astrophotography. In 1987 plans were set into motion to raise money to build a permanent Observatory on the roof of the main classroom building. Fundraising efforts included three Jog-A-Thons (raising more than $40,000) and many donations from individuals and foundations. The fundraising was completed in 1996 and a two telescope observatory was constructed in the summer of 1996 complete with warm room, CCD cameras, computers, spectrograph, video network, and computerized single channel photometer. The telescopes are computerized 16" diameter Meade LX200 Schmidt-Cassegrains, each coupled to Gateway Pentium Pro 200 MHz computers. SBIG ST-8 CCD cameras were also secured for each telescope and an Optec SSP-7 photometer and Optomechanics Research 10C Spectrograph were also purchased. A Daystar H-alpha solar filter and Thousand Oaks visual light solar filter have expanded the Observatory's functionality to daytime observing as well. This is especially useful for the thousands of school children who frequent the Planetarium each year. The Observatory primarily serves the core astronomy lab where students must observe and photograph a prescribed number of celestial objects in a semester. Advanced students can take directed studies where they conduct photometry on eclipsing binaries or other variable stars or search for new asteroids. In addition, the Observatory and Planetarium are open to the public. Interested members of the community can reserve time on the telescopes and receive training and supervision from lab assistants. The lessons learned from building the Observatory as well as structural plans, equipment and curriculum development will be discussed in this poster.