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Sample records for faint object infrared

  1. NIFTE: The Near Infrared Faint-Object Telescope Experiment

    NASA Technical Reports Server (NTRS)

    Bock, James J.; Lange, Andrew E.; Matsumoto, T.; Eisenhardt, Peter B.; Hacking, Perry B.; Schember, Helene R.

    1994-01-01

    The high sensitivity of large format InSb arrays can be used to obtain deep images of the sky at 3-5 micrometers. In this spectral range cool or highly redshifted objects (e.g. brown dwarfs and protogalaxies) which are not visible at shorter wavelengths may be observed. Sensitivity at these wavelengths in ground-based observations is severly limited by the thermal flux from the telescope and from the earth's atmosphere. The Near Infrared Faint-Object Telescope Experiment (NIFTE), a 50 cm cooled rocket-borne telescope combined with large format, high performance InSb arrays, can reach a limiting flux less than 1 micro-Jy(1-sigma) over a large field-of-view in a single flight. In comparison, the Infrared Space Observatory (ISO) will require days of observation to reach a sensitivity more than one order of magnitude worse over a similar area of the sky. The deep 3-5 micrometer images obtained by the rocket-borne telescope will assist in determining the nature of faint red objects detected by ground-based telescopes at 2 micrometers, and by ISO at wavelengths longer than 5 micrometers.

  2. A Study of Planetary Nebulae using the Faint Object Infrared Camera for the SOFIA Telescope

    NASA Technical Reports Server (NTRS)

    Davis, Jessica

    2012-01-01

    A planetary nebula is formed following an intermediate-mass (1-8 solar M) star's evolution off of the main sequence; it undergoes a phase of mass loss whereby the stellar envelope is ejected and the core is converted into a white dwarf. Planetary nebulae often display complex morphologies such as waists or torii, rings, collimated jet-like outflows, and bipolar symmetry, but exactly how these features form is unclear. To study how the distribution of dust in the interstellar medium affects their morphology, we utilize the Faint Object InfraRed CAmera for the SOFIA Telescope (FORCAST) to obtain well-resolved images of four planetary nebulae--NGC 7027, NGC 6543, M2-9, and the Frosty Leo Nebula--at wavelengths where they radiate most of their energy. We retrieve mid infrared images at wavelengths ranging from 6.3 to 37.1 micron for each of our targets. IDL (Interactive Data Language) is used to perform basic analysis. We select M2-9 to investigate further; analyzing cross sections of the southern lobe reveals a slight limb brightening effect. Modeling the dust distribution within the lobes reveals that the thickness of the lobe walls is higher than anticipated, or rather than surrounding a vacuum surrounds a low density region of tenuous dust. Further analysis of this and other planetary nebulae is needed before drawing more specific conclusions.

  3. Faint Object Spectrograph (FOS) calibration

    NASA Technical Reports Server (NTRS)

    Harms, R. J.; Beaver, E. A.; Burbidge, E. M.; Angel, J. R. P.; Bartko, F.; Mccoy, J.; Ripp, L.; Bohlin, R.; Davidsen, A. F.; Ford, H.

    1982-01-01

    The Faint Object Spectrograph (FOS) designed for use with The Space Telescope (ST), is currently preparing for instrument assembly, integration, alignment, and calibration. Nearly all optical and detector elements have been completed and calibrated, and selection of flight detectors and all but a few optical elements has been made. Calibration results for the flight detectors and optics are presented, and plans for forthcoming system calibration are briefly described.

  4. Orbital objects detection algorithm using faint streaks

    NASA Astrophysics Data System (ADS)

    Tagawa, Makoto; Yanagisawa, Toshifumi; Kurosaki, Hirohisa; Oda, Hiroshi; Hanada, Toshiya

    2016-02-01

    This study proposes an algorithm to detect orbital objects that are small or moving at high apparent velocities from optical images by utilizing their faint streaks. In the conventional object-detection algorithm, a high signal-to-noise-ratio (e.g., 3 or more) is required, whereas in our proposed algorithm, the signals are summed along the streak direction to improve object-detection sensitivity. Lower signal-to-noise ratio objects were detected by applying the algorithm to a time series of images. The algorithm comprises the following steps: (1) image skewing, (2) image compression along the vertical axis, (3) detection and determination of streak position, (4) searching for object candidates using the time-series streak-position data, and (5) selecting the candidate with the best linearity and reliability. Our algorithm's ability to detect streaks with signals weaker than the background noise was confirmed using images from the Australia Remote Observatory.

  5. Are the infrared-faint radio sources pulsars?

    NASA Astrophysics Data System (ADS)

    Cameron, A. D.; Keith, M.; Hobbs, G.; Norris, R. P.; Mao, M. Y.; Middelberg, E.

    2011-07-01

    Infrared-faint radio sources (IFRS) are objects which are strong at radio wavelengths but undetected in sensitive Spitzer observations at infrared wavelengths. Their nature is uncertain and most have not yet been associated with any known astrophysical object. One possibility is that they are radio pulsars. To test this hypothesis we undertook observations of 16 of these sources with the Parkes Radio Telescope. Our results limit the radio emission to a pulsed flux density of less than 0.21 mJy (assuming a 50 per cent duty cycle). This is well below the flux density of the IFRS. We therefore conclude that these IFRS are not radio pulsars.

  6. Faint object 3D spectroscopy with PMAS

    NASA Astrophysics Data System (ADS)

    Roth, Martin M.; Becker, Thomas; Kelz, Andreas; Bohm, Petra

    2004-09-01

    PMAS is a fiber-coupled lens array type of integral field spectrograph, which was commissioned at the Calar Alto 3.5m Telescope in May 2001. The optical layout of the instrument was chosen such as to provide a large wavelength coverage, and good transmission from 0.35 to 1 μm. One of the major objectives of the PMAS development has been to perform 3D spectrophotometry, taking advantage of the contiguous array of spatial elements over the 2-dimensional field-of-view of the integral field unit. With science results obtained during the first two years of operation, we illustrate that 3D spectroscopy is an ideal tool for faint object spectrophotometry.

  7. PMAS - Faint Object 3D Spectrophotometry

    NASA Astrophysics Data System (ADS)

    Roth, M. M.; Becker, T.; Kelz, A.

    2002-01-01

    will describe PMAS (Potsdam Multiaperture Spectrophotometer) which was commissioned at the Calar Alto Observatory 3.5m Telescope on May 28-31, 2001. PMAS is a dedicated, highly efficient UV-visual integral field spectrograph which is optimized for the spectrophotometry of faint point sources, typically superimposed on a bright background. PMAS is ideally suited for the study of resolved stars in local group galaxies. I will present results of our preliminary work with MPFS at the Russian 6m Telescope in Selentchuk, involving the development of new 3D data reduction software, and observations of faint planetary nebulae in the bulge of M31 for the determination of individual chemical abundances of these objects. Using this data, it will be demonstrated that integral field spectroscopy provides superior techniques for background subtraction, avoiding the otherwise inevitable systematic errors of conventional slit spetroscopy. The results will be put in perspective of the study of resolved stellar populations in nearby galaxies with a new generation of Extremely Large Telescopes.

  8. Morphology and astrometry of Infrared-Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Middelberg, Enno; Norris, Ray; Randall, Kate; Mao, Minnie; Hales, Christopher

    2008-10-01

    Infrared-Faint Radio Sources, or IFRS, are an unexpected class of object discovered in the Australia Telescope Large Area Survey, ATLAS. They are compact 1.4GHz radio sources with no visible counterparts in co-located (relatively shallow) Spitzer infrared and optical images. We have detected two of these objects with VLBI, indicating the presence of an AGN. These observations and our ATLAS data indicate that IFRS are extended on scales of arcseconds, and we wish to image their morphologies to obtain clues about their nature. These observations will also help us to select optical counterparts from very deep, and hence crowded, optical images which we have proposed. With these data in hand, we will be able to compare IFRS to known object types and to apply for spectroscopy to obtain their redshifts.

  9. Fainting

    MedlinePlus

    Fainting is a temporary loss of consciousness. If you're about to faint, you'll feel dizzy, ... at the same time, and may fall down. Fainting usually happens when your blood pressure drops suddenly, ...

  10. Astronomical capabilities of the Faint Object Spectrograph on Space Telescope

    NASA Technical Reports Server (NTRS)

    Harms, R. J.

    1982-01-01

    Examples of scientific observing programs planned with the Faint Object Spectrograph on Space Telescope are presented. An overview of the spectrograph design and operation is presented. The expected astronomical performance of the instrument is described in some detail.

  11. VLBI observations of Infrared-Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Middelberg, Enno; Phillips, Chris; Norris, Ray; Tingay, Steven

    2006-10-01

    We propose to observe a small sample of radio sources from the ATLAS project (ATLAS = Australia Telescope Large Area Survey) with the LBA, to determine their compactness and map their structures. The sample consists of three radio sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubbed Infrared-Faint Radio Sources, or IFRS, is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations: we will map their structure to test whether they resemble core-jet or double-lobed morphologies, and we will measure the flux densities on long baselines, to determine their compactness. Previous snapshot-style LBA observations of two other IFRS yielded no detections, hence we propose to use disk-based recording with 512 Mbps where possible, for highest sensitivity. With the observations proposed here, we will increase the number of VLBI-observed IFRS from two to five, soon allowing us to draw general conclusions about this intriguing new class of objects.

  12. X-ray Counterparts of Infrared Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Schartel, Norbert

    2011-10-01

    Infrared Faint Radio Sources (IFRS) are radio sources with extremely faint or even absent infrared emission in deep Spitzer Surveys. Models of their spectral energy distributions, the ratios of radio to infrared flux densities and their steep radio spectra strongly suggest that IFRS are AGN at high redshifts (2infrared fluxes, will constrain the class-specific SED.

  13. Fainting

    MedlinePlus

    ... muscle control at the same time, and may fall down. Fainting usually happens when your blood pressure drops suddenly, causing a decrease in blood flow to your brain. It is more common in older people. Some causes of fainting include Heat or dehydration ...

  14. Fainting

    MedlinePlus

    ... En Español Making a Change – Your Personal Plan Hot Topics Meningitis Choosing Your Mood Prescription Drug Abuse ... reasons why teens faint: Physical triggers. Getting too hot or being in a crowded, poorly ventilated setting ...

  15. Fainting

    MedlinePlus

    ... of fainting: Certain medicines, including those used for anxiety, depression, and high blood pressure (these drugs may cause a drop in blood pressure) Drug or alcohol use Hyperventilation Low blood sugar Seizures Sudden drop in blood pressure (such as ...

  16. Fainting

    MedlinePlus

    ... brain does not get enough oxygen. You lose consciousness, or "pass out," for a brief time (usually ... Taking longer than a few seconds to regain consciousness Fainting when you turn your head to the ...

  17. Evidence for Infrared-faint Radio Sources as z > 1 Radio-loud Active Galactic Nuclei

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.; Norris, Ray P.; Siana, Brian; Middelberg, Enno

    2010-02-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey which have no observable mid-infrared counterpart in the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6-70 μm) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the spectral energy distribution of these objects shows that they are consistent with high-redshift (z >~ 1) active galactic nuclei.

  18. The radio properties of infrared-faint radio sources

    NASA Astrophysics Data System (ADS)

    Middelberg, E.; Norris, R. P.; Hales, C. A.; Seymour, N.; Johnston-Hollitt, M.; Huynh, M. T.; Lenc, E.; Mao, M. Y.

    2011-02-01

    Context. Infrared-faint radio sources (IFRS) are objects that have flux densities of several mJy at 1.4 GHz, but that are invisible at 3.6 μm when using sensitive Spitzer observations with μJy sensitivities. Their nature is unclear and difficult to investigate since they are only visible in the radio. Aims: High-resolution radio images and comprehensive spectral coverage can yield constraints on the emission mechanisms of IFRS and can give hints to similarities with known objects. Methods: We imaged a sample of 17 IFRS at 4.8 GHz and 8.6 GHz with the Australia Telescope Compact Array to determine the structures on arcsecond scales. We added radio data from other observing projects and from the literature to obtain broad-band radio spectra. Results: We find that the sources in our sample are either resolved out at the higher frequencies or are compact at resolutions of a few arcsec, which implies that they are smaller than a typical galaxy. The spectra of IFRS are remarkably steep, with a median spectral index of -1.4 and a prominent lack of spectral indices larger than -0.7. We also find that, given the IR non-detections, the ratio of 1.4 GHz flux density to 3.6 μm flux density is very high, and this puts them into the same regime as high-redshift radio galaxies. Conclusions: The evidence that IFRS are predominantly high-redshift sources driven by active galactic nuclei (AGN) is strong, even though not all IFRS may be caused by the same phenomenon. Compared to the rare and painstakingly collected high-redshift radio galaxies, IFRS appear to be much more abundant, but less luminous, AGN-driven galaxies at similar cosmological distances.

  19. Spectrophotometric Redshifts in the Faint Infrared Grism Survey

    NASA Astrophysics Data System (ADS)

    Pharo, John; Malhotra, Sangeeta; Rhoads, James E.

    2016-06-01

    We have combined HST grism spectroscopy and deep broadband imaging to measure spectro-photometric redshifts (SPZs) of faint galaxies. Using a technique pioneered by Ryan et al. 2007, one can combine spectra and photometry to yield an SPZ that is more accurate than pure photometric redshifts, and can probe more deeply than ground-based spectroscopic redshifts. By taking mid-resolution spectra from the HST Faint Infrared Grism Survey (FIGS), SPZs can be found for measurements potentially down to 27th magnitude (the typical brightness of a dwarf galaxy at redshift ∼1.5). A galaxy’s redshift is vital for understanding its place in the growth and evolution of the universe. The measurement of high-accuracy SPZs for FIGS sources will improve the faint-end and high-redshift portions of the luminosity function, and make possible a robust analysis of the FIGS fields for signs of Large Scale Structure (LSS). The improved redshift and distance measurements allowed for the identification of a structure at z=0.83 in one of the FIGS fields.

  20. Infrared Faint Radio Sources in the Extended Chandra Deep Field South

    NASA Astrophysics Data System (ADS)

    Huynh, Minh T.

    2009-01-01

    Infrared-Faint Radio Sources (IFRSs) are a class of radio objects found in the Australia Telescope Large Area Survey (ATLAS) which have no observable counterpart in the Spitzer Wide-area Infrared Extragalactic Survey (SWIRE). The extended Chandra Deep Field South now has even deeper Spitzer imaging (3.6 to 70 micron) from a number of Legacy surveys. We report the detections of two IFRS sources in IRAC images. The non-detection of two other IFRSs allows us to constrain the source type. Detailed modeling of the SED of these objects shows that they are consistent with high redshift AGN (z > 2).

  1. Faint Blue Objects in the Hubble Deep Field North

    NASA Astrophysics Data System (ADS)

    Kilic, M.; von Hippel, T.; Mendez, R. A.; Winget, D. E.

    2005-07-01

    Using the deepest and finest resolution images of the Universe acquired with the Hubble Space Telescope and a similar image taken 7 years later for the Great Observatories Origins Deep Survey, we have derived proper motions for the point sources in the Hubble Deep Field-North. Two faint blue objects, HDF2234 and HDF3072, are found to display significant proper motions, 10.0 ± 2.5 and 15.5 ± 3.8 mas yr-1. Photometric distances and tangential velocities for these stars are consistent with disk white dwarfs located at ≈500 pc. At least one of these two objects now appears spectroscopically to be a white dwarf (Kilic et al., in preparation). The faint blue objects analyzed by Ibata et al. (1999) and Mendez & Minniti (2000) do not show any significant proper motion; they are not halo white dwarfs and they do not contribute to the Galactic dark matter. These objects are likely to be distant AGN.

  2. Stellar Ultraviolet Rocket Research Program. [faint object spectrograph

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A 1/4 meter ultraviolet spectrometer, developed to measure the ultraviolet flux from several standard type stars was flown successfully on Aerobee rockets. The ultraviolet flux from alpha Lyr, eta U Ma, zeta Oph, delta Ori, alpha CMa, beta CMa, and alpha Leo were measured. These values agreed with the OAO data obtained by Code in the 1200 to 3400 A region to + or - 9%. The design and calibration of a faint object spectrometer for observing stars and nebula with a 3 A resolution and a 3% accuracy in a 60 second observation are discussed.

  3. The Faint Object Camera for the Space Telescope

    NASA Astrophysics Data System (ADS)

    Bartholomae, K.-P.; Schmidt, G.

    1981-05-01

    The Faint Object Camera (FOC), one of the four axial scientific instruments located at the focal plane of the NASA Space Telescope, is described. The FOC has overall dimensions of approximately 0.9 x 0.9 x 2.2 cu m, a total weight of about 322 kg, and an average power consumption per orbit of less than 150 W. The FOC is made up of two complete and independent camera systems, each with its dedicated three mirrors optical relay and photon detector device operating in a wavelength range of 1200 A to 7000 A.

  4. Do the enigmatic ``Infrared-Faint Radio Sources'' include pulsars?

    NASA Astrophysics Data System (ADS)

    Hobbs, George; Middelberg, Enno; Norris, Ray; Keith, Michael; Mao, Minnie; Champion, David

    2009-04-01

    The Australia Telescope Large Area Survey (ATLAS) team have surveyed seven square degrees of sky at 1.4GHz. During processing some unexpected infrared-faint radio sources (IFRS sources) were discovered. The nature of these sources is not understood, but it is possible that some of these sources may be pulsars within our own galaxy. We propose to observe the IFRS sources with steep spectral indices using standard search techniques to determine whether or not they are pulsars. A pulsar detection would 1) remove a subset of the IFRS sources from the ATLAS sample so they would not need to be observed with large optical/IR telescopes to find their hosts and 2) be intrinsically interesting as the pulsar would be a millisecond pulsar and/or have an extreme spatial velocity.

  5. Calibration and operation of the Faint Object Spectrograph

    NASA Technical Reports Server (NTRS)

    Harms, R.; Beaver, E.; Burbidge, E.; Hier, R.; Allen, R.; Angel, R.; Bartko, F.; Bohlin, R.; Ford, H.; Davidson, A.

    1984-01-01

    The design and basic performance characteristics of the Faint Object Spectrograph (FOS), one of five instruments built for use on the Space Telescope observatory, is summarized briefly. The results of the recently completed instrument-level calibration are presented with special emphasis on issues affecting plans for FOS astronomical observations. Examples include such fundamental characteristics as: limiting magnitudes (system sensitivity and noise figures), spectral coverage and resolution, scattered light properties, and instrumental polarization and modulation efficiencies. Also gated toward intended users, a rather detailed description of FOS operating modes is given. The discussion begins with the difficulties anticipated during target acquisition and their hoped-for resolution. Both the 'normal' spectroscopic operating modes of the FOS and its 'exotic' features (e.g. spectropolarimetric, time-tagged, and time-resolved modes) are presented. The paper concludes with an overview of the activities to assure proper alignment and operation of the FOS within the entire Space Telescope system (orbital and ground-based).

  6. Infrared-faint radio sources are at high redshifts. Spectroscopic redshift determination of infrared-faint radio sources using the Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Herzog, A.; Middelberg, E.; Norris, R. P.; Sharp, R.; Spitler, L. R.; Parker, Q. A.

    2014-07-01

    Context. Infrared-faint radio sources (IFRS) are characterised by relatively high radio flux densities and associated faint or even absent infrared and optical counterparts. The resulting extremely high radio-to-infrared flux density ratios up to several thousands were previously known only for high-redshift radio galaxies (HzRGs), suggesting a link between the two classes of object. However, the optical and infrared faintness of IFRS makes their study difficult. Prior to this work, no redshift was known for any IFRS in the Australia Telescope Large Area Survey (ATLAS) fields which would help to put IFRS in the context of other classes of object, especially of HzRGs. Aims: This work aims at measuring the first redshifts of IFRS in the ATLAS fields. Furthermore, we test the hypothesis that IFRS are similar to HzRGs, that they are higher-redshift or dust-obscured versions of these massive galaxies. Methods: A sample of IFRS was spectroscopically observed using the Focal Reducer and Low Dispersion Spectrograph 2 (FORS2) at the Very Large Telescope (VLT). The data were calibrated based on the Image Reduction and Analysis Facility (IRAF) and redshifts extracted from the final spectra, where possible. This information was then used to calculate rest-frame luminosities, and to perform the first spectral energy distribution modelling of IFRS based on redshifts. Results: We found redshifts of 1.84, 2.13, and 2.76, for three IFRS, confirming the suggested high-redshift character of this class of object. These redshifts and the resulting luminosities show IFRS to be similar to HzRGs, supporting our hypothesis. We found further evidence that fainter IFRS are at even higher redshifts. Conclusions: Considering the similarities between IFRS and HzRGs substantiated in this work, the detection of IFRS, which have a significantly higher sky density than HzRGs, increases the number of active galactic nuclei in the early universe and adds to the problems of explaining the formation of

  7. Astrometric Follow-Up of Faint Near Earth Objects

    NASA Technical Reports Server (NTRS)

    Morgan, T. (Technical Monitor); Spahr, Timothy

    2004-01-01

    The observing program at Mt. Hopkins using the 48" reflector and funded by the Near- Earth Object Observation Program continues to excel. As in the past, all requested observing time was granted. Minor improvements continue to be made. For example, the telescope is set up to track and non-sidereal rates. This allows the user to track on the target object, rather than relying exclusively on the shift- and-stack technique. Other improvements made by the staff include automatic focus routines, automatic seeing-measurement routines, and improvement in dome seeing and mirror stabilization. The net result is better focus, better seeing, and the ability to expose longer in order to acquire the faintest and most important objects. During the proposal period, this program ranked again very high worldwide in terms of faint Near Earth Objects observed. During this latest proposal cycle, fewer objects were observed than previous cycles, but this was due to the strict targeting of only the faintest observable objects. The follow-up programs of observatory codes 926 (led by P. Holvorcem) and 291 (led by Dr. B. McMillan) have greatly increased their capacity, and as a result less bright objects are in urgent need of follow-up than in years past. Even with this new object selection and additional competition, code 696 still ranked second to code 291 in terms of objects observed fainter than V = 20. Minimal scripting is now in place to allow the telescope to run autonomously for 30-45 minutes at a time.

  8. Image Stacking Method Application for Low Earth Orbit Faint Objects

    NASA Astrophysics Data System (ADS)

    Tagawa, M.; Matsumoto, H.; Yanagisawa, T.; Kurosaki, H.; Oda, H.; Kitazawa, Y.; Hanada, T.

    2013-09-01

    Space situational awareness is one of the most important actions for safe and sustainable space development and its utilization. Tracking and maintaining debris catalog are the basis of the actions. Current minimum size of objects in the catalog that routinely tracked and updated is approximately 10 cm in the Low Earth Orbit region. This paper proposes collaborative observation of space-based sensors and ground facilities to improve tracking capability in low Earth orbit. This observation geometry based on role-sharing idea. A space-based sensor has advantage in sensitivity and observation opportunity however, it has disadvantages in periodic observation which is essential for catalog maintenance. On the other hand, a ground facility is inferior to space-based sensors in sensitivity however; observation network composed of facilities has an advantage in periodic observation. Whole observation geometry is defined as follows; 1) space-based sensors conduct initial orbit estimation for a target 2) ground facility network tracks the target based on estimated orbit 3) the network observes the target periodically and updates its orbit information. The second phase of whole geometry is based on image stacking method developed by the Japan aerospace exploration agency and this method is verified for objects in geostationary orbit. This method enables to detect object smaller than a nominal size limitation by stacking faint light spot along archived time-series frames. The principle of this method is prediction and searching target's motion on the images. It is almost impossible to apply the method to objects in Low Earth Orbit without proper orbit information because Low Earth Orbit objects have varied orbital characteristics. This paper discusses whether or not initial orbit estimation results given by space-based sensors have enough accuracy to apply image stacking method to Low Earth Orbit objects. Ground-based observation procedure is assumed as being composed of

  9. Detection of faint celestial objects by small telescopes

    NASA Astrophysics Data System (ADS)

    Savanevich, Vadim; Bryukhovetskiy, Alexandr; Kozhukhov, Alexandr; Ivaschenko, Yuri; Velichko, Feodor

    an object from class of "Possible objects" by MAST at the multi-frame processing step; • identification of star pattern at the frame via star catalog, calculating rect-angular and angular coordinates of objects. • check-up the obtained measurements with MPC data base, discharge the known objects and forming the decision about new ones. Observations of asteroids were carried out with 60-cm Zeiss reflector at Andrushivka stronomical bservatory (MPC-code A50). Telescope was equipped by FLI PL9000 camera that has CCD array of 3056x3056 pixels. It was possible to detect objects no fainter then 20m of visual brightness for the exposure of 30 sec. It was confirmed, that the method has the reliability of detection of faint objects with nonzero visible motion close to the reliability of detection of motionless ones.

  10. Faint Object Camera imaging and spectroscopy of NGC 4151

    NASA Technical Reports Server (NTRS)

    Boksenberg, A.; Catchpole, R. M.; Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.

    1995-01-01

    We describe ultraviolet and optical imaging and spectroscopy within the central few arcseconds of the Seyfert galaxy NGC 4151, obtained with the Faint Object Camera on the Hubble Space Telescope. A narrowband image including (O III) lambda(5007) shows a bright nucleus centered on a complex biconical structure having apparent opening angle approximately 65 deg and axis at a position angle along 65 deg-245 deg; images in bands including Lyman-alpha and C IV lambda(1550) and in the optical continuum near 5500 A, show only the bright nucleus. In an off-nuclear optical long-slit spectrum we find a high and a low radial velocity component within the narrow emission lines. We identify the low-velocity component with the bright, extended, knotty structure within the cones, and the high-velocity component with more confined diffuse emission. Also present are strong continuum emission and broad Balmer emission line components, which we attribute to the extended point spread function arising from the intense nuclear emission. Adopting the geometry pointed out by Pedlar et al. (1993) to explain the observed misalignment of the radio jets and the main optical structure we model an ionizing radiation bicone, originating within a galactic disk, with apex at the active nucleus and axis centered on the extended radio jets. We confirm that through density bounding the gross spatial structure of the emission line region can be reproduced with a wide opening angle that includes the line of sight, consistent with the presence of a simple opaque torus allowing direct view of the nucleus. In particular, our modelling reproduces the observed decrease in position angle with distance from the nucleus, progressing initially from the direction of the extended radio jet, through our optical structure, and on to the extended narrow-line region. We explore the kinematics of the narrow-line low- and high-velocity components on the basis of our spectroscopy and adopted model structure.

  11. Faint Object Spectrograph Instrument Handbook v. 6.0

    NASA Astrophysics Data System (ADS)

    Keyes, C. D.; et al.

    1995-06-01

    This Handbook describes The Faint Object Spectrograph (FOS) and its use for Cycle 6 of the Hubble Space Telescope General Observer program. Many presentations have been updated from previous versions, especially those pertaining to target acquisition, brightness limits, and in- strumental sensitivities needed for exposure and S/N calculations. This Handbook draws upon dis- cussions from earlier versions of the Handbook, notably the Version 1.0 FOS Instrument Handbook (Ford 1985), the Supplement to the Version 1.0 Instrument Handbook (Hartig 1989), and the Version 5.0 Handbook (Kinney, 1994). Only the current document should be used for Cy- cle 6. The detectors are described in detail by Harms et al (1979) and Harms (1982). This version of the FOS Instrument Handbook is for the post-COSTAR refurbished tele- scope. The change in focal length introduced by the addition of COSTAR affects the aperture sizes as projected on the sky. However, the pre-COSTAR aperture designations used in the Remote Pro- posal Submission System, version 2 (RPS2) and in the Project Data Base (PDB) have not been changed. Apertures are referred to throughout this document by their size followed in parentheses by their RPS2 exposure level designation (in Courier typeface). Indeed, all RPS2 desig- nations, which are used for proposal preparation, will be denoted in Courier typeface in this Hand- book. For example, the largest circular aperture is referred to as the 0.9'' (1.0) aperture, while the smallest paired apertures are referred to as the 0.09'' paired (0.1-PAIR)apertures.

  12. NEUTRAL GAS OUTFLOWS AND INFLOWS IN INFRARED-FAINT SEYFERT GALAXIES

    SciTech Connect

    Krug, Hannah B.; Veilleux, Sylvain; Rupke, David S. N. E-mail: veilleux@astro.umd.ed

    2010-01-10

    Previous studies of the Na I D interstellar absorption line doublet have shown that galactic winds occur in most galaxies with high infrared luminosities. However, in infrared-bright composite systems where a starburst coexists with an active galactic nucleus (AGN), it is unclear whether the starburst, the AGN, or both are driving the outflows. The present paper describes the results from a search for outflows in 35 infrared-faint Seyferts with 10{sup 9.9}< L{sub IR}/L{sub sun} < 10{sup 11}, or, equivalently, star formation rates (SFRs) of approx0.4-9 M{sub sun} yr{sup -1}, to attempt to isolate the source of the outflow. We find that the outflow detection rates for the infrared-faint Seyfert 1s (6%) and Seyfert 2s (18%) are lower than previously reported for infrared-luminous Seyfert 1s (50%) and Seyfert 2s (45%). The outflow kinematics of infrared-faint and infrared-bright Seyfert 2 galaxies resemble those of starburst galaxies, while the outflow velocities in Seyfert 1 galaxies are significantly larger. Taken together, these results suggest that the AGN does not play a significant role in driving the outflows in most infrared-faint and infrared-bright systems, except the high-velocity outflows seen in Seyfert 1 galaxies. Another striking result of this study is the high rate of detection of inflows in infrared-faint galaxies (39% of Seyfert 1s, 35% of Seyfert 2s), significantly larger than in infrared-luminous Seyferts (15%). This inflow may be contributing to the feeding of the AGN in these galaxies, and potentially provides more than enough material to power the observed nuclear activity over typical AGN lifetimes.

  13. The first VLBI image of an infrared-faint radio source

    NASA Astrophysics Data System (ADS)

    Middelberg, E.; Norris, R. P.; Tingay, S.; Mao, M. Y.; Phillips, C. J.; Hotan, A. W.

    2008-11-01

    Context: We investigate the joint evolution of active galactic nuclei and star formation in the Universe. Aims: In the 1.4 GHz survey with the Australia Telescope Compact Array of the Chandra Deep Field South and the European Large Area ISO Survey - S1 we have identified a class of objects which are strong in the radio but have no detectable infrared and optical counterparts. This class has been called Infrared-Faint Radio Sources, or IFRS. 53 sources out of 2002 have been classified as IFRS. It is not known what these objects are. Methods: To address the many possible explanations as to what the nature of these objects is we have observed four sources with the Australian Long Baseline Array. Results: We have detected and imaged one of the four sources observed. Assuming that the source is at a high redshift, we find its properties in agreement with properties of Compact Steep Spectrum sources. However, due to the lack of optical and infrared data the constraints are not particularly strong.

  14. Infrared-faint radio sources remain undetected at far-infrared wavelengths. Deep photometric observations using the Herschel Space Observatory

    NASA Astrophysics Data System (ADS)

    Herzog, A.; Norris, R. P.; Middelberg, E.; Spitler, L. R.; Leipski, C.; Parker, Q. A.

    2015-08-01

    Context. Showing 1.4 GHz flux densities in the range of a few to a few tens of mJy, infrared-faint radio sources (IFRS) are a type of galaxy characterised by faint or absent near-infrared counterparts and consequently extreme radio-to-infrared flux density ratios up to several thousand. Recent studies showed that IFRS are radio-loud active galactic nuclei (AGNs) at redshifts ≳2, potentially linked to high-redshift radio galaxies (HzRGs). Aims: This work explores the far-infrared emission of IFRS, providing crucial information on the star forming and AGN activity of IFRS. Furthermore, the data enable examining the putative relationship between IFRS and HzRGs and testing whether IFRS are more distant or fainter siblings of these massive galaxies. Methods: A sample of six IFRS was observed with the Herschel Space Observatory between 100 μm and 500 μm. Using these results, we constrained the nature of IFRS by modelling their broad-band spectral energy distribution (SED). Furthermore, we set an upper limit on their infrared SED and decomposed their emission into contributions from an AGN and from star forming activity. Results: All six observed IFRS were undetected in all five Herschel far-infrared channels (stacking limits: σ = 0.74 mJy at 100 μm, σ = 3.45 mJy at 500 μm). Based on our SED modelling, we ruled out the following objects to explain the photometric characteristics of IFRS: (a) known radio-loud quasars and compact steep-spectrum sources at any redshift; (b) starburst galaxies with and without an AGN and Seyfert galaxies at any redshift, even if the templates were modified; and (c) known HzRGs at z ≲ 10.5. We find that the IFRS analysed in this work can only be explained by objects that fulfil the selection criteria of HzRGs. More precisely, IFRS could be (a) known HzRGs at very high redshifts (z ≳ 10.5); (b) low-luminosity siblings of HzRGs with additional dust obscuration at lower redshifts; (c) scaled or unscaled versions of Cygnus A at any

  15. Four QSOs found in a survey of faint objects

    NASA Astrophysics Data System (ADS)

    Morton, D. C.; Tritton, K. P.

    1982-02-01

    Four quasars with redshifts z = 0.6185, 0.6267, 0.850, and 1.665 have been found in the central 33.4 arcmin square of the field at 22h.05, -18deg.91 surveyed by Savage and Bolton (1979) and Krug et al. (1980). The first two quasars are separated by 6.8 arcmin and may be associated with groups of faint galaxies. The separation is well within the 20 Mpc or larger dimensions suggested by Oort et al. (1981) for superclusters, and the velocity difference is not unusual if the velocity dispersion is near the upper end of the range of 300-600 km/s

  16. A search for AGN activity in Infrared-Faint Radio Sources (IFRS)

    NASA Astrophysics Data System (ADS)

    Lenc, Emil; Middelberg, Enno; Norris, Ray; Mao, Minnie

    2009-04-01

    We propose to observe a large sample of radio sources from the ATLAS (Australia Telescope Large Area Survey) source catalogue with the LBA, to determine their compactness. The sample consists of 36 sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubber Infrared-Faint Radio Sources (IFRS), is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations. We will measure the flux densities on long baselines to determine their compactness. Only five IFRS have been previously targeted with VLBI observations (resulting in two detections). We propose using single baseline (Parkes-ATCA) eVLBI observations with the LBA at 1 Gbps to maximise sensitivity. With the observations proposed here we will increase the number of VLBI-observed IFRS from 5 to 36, allowing us to draw statistical conclusions about this intriguing new class of objects.

  17. A search for AGN activity in Infrared-Faint Radio Sources (IFRS)

    NASA Astrophysics Data System (ADS)

    Lenc, Emil; Middelberg, Enno; Norris, Ray; Mao, Minnie

    2010-04-01

    We propose to observe a large sample of radio sources from the ATLAS (Australia Telescope Large Area Survey) source catalogue with the LBA, to determine their compactness. The sample consists of 36 sources with no counterpart in the co-located SWIRE survey (3.6 um to 160 um), carried out with the Spitzer Space Telescope. This rare class of sources, dubber Infrared-Faint Radio Sources (IFRS), is inconsistent with current galaxy evolution models. VLBI observations are an essential way to obtain further clues on what these objects are and why they are hidden from infrared observations. We will measure the flux densities on long baselines to determine their compactness. Only five IFRS have been previously targeted with VLBI observations (resulting in two detections). We propose using single baseline (Parkes-ATCA) eVLBI observations with the LBA at 1 Gbps to maximise sensitivity. With the observations proposed here we will increase the number of VLBI-observed IFRS from 5 to 36, allowing us to draw statistical conclusions about this intriguing new class of objects.

  18. Infrared guiding with faint stars with the wide-field infrared camera at CFHT

    NASA Astrophysics Data System (ADS)

    Teeple, Douglas; Riopel, Martin; Baril, Marc; Barrick, Gregory; Albert, Loic; Vermeulen, Tom; Ward, Jeff

    2006-06-01

    The Canada-France-Hawaii Telescope (CFHT) is commissioning a new Wide field Infrared Camera (WIRCam) that uses a mosaic of 4 HAWAII-2RG near- infrared detectors manufactured by Rockwell. At the heart of the instrument is an On-Chip Guiding System (OCGS) that exploits the unique parallel science/guide frame readout capability of the HAWAII-2RG detectors. A small sub sample of each array is continuously read at a rate of up to 50 Hz while the integration of the science image is ongoing with the full arrays (read at a maximal rate of 1.4 s per full frame). Each of these guiding windows is centered on a star to provide an error signal for the telescope guiding. An Image Stabilizer Unit (ISU) (i.e. a tip-tilt silica plate), provides the corrections. A Proportional Integral Differential (PID) closed loop controls the ISU such that telescope tracking is corrected at a rate of 5 Hz. This paper presents the technical architecture of the guiding system and performance measurements on the sky in engineering runs with WIRCam with faint stars up to magnitude 14.

  19. NOTE: Red, Gray, and Blue: Near Infrared Spectrophotometry of Faint Moons of Uranus and Neptune

    NASA Astrophysics Data System (ADS)

    Trilling, David E.; Brown, Robert H.

    2000-11-01

    Using the CoCo Cold Coronagraph at NASA's Infrared Telescope Facility on Mauna Kea, we observed the uranian satellites Miranda, Puck, Portia, and Rosalind and the neptunian satellite Proteus in the near infrared (JHK) to determine the albedos of those faint satellites. In V-J, all of Puck, Portia, Rosalind, and Proteus are very blue, similar to the colors of many icy satellites and of water ice. The satellites we observed have a wide range of J-H colors, with Miranda being blue, Proteus being gray, and Puck, Portia, and Rosalind being red. For the satellites for which we could determine H-K (Miranda, Puck, and Proteus), the colors are gray to red. As a whole, spectrally, these five satellites lie between icy Solar System satellites (e.g., saturnian satellites or the major uranian satellites) and Kuiper belt objects. The redness of Proteus and Puck and perhaps other satellites suggests the presence of organic material, although the redness is also similar to that of C- and D-class asteroids and some outer jovian moons. In all cases, diagnostic spectral features could be masked by broadband photometry.

  20. The U.S. survey for faint blue objects

    NASA Technical Reports Server (NTRS)

    Mitchell, K. J.; Howell, S. B.; Usher, P. D.

    1987-01-01

    A spectrophotometric study of the blue and UV-excess starlike objects in the U.S. survey (Usher, 1981) has been conducted. Observations were obtained with a resolution of about 20 A over the 3500-7000-A wavelength range. Considered within the sample are 42 DA white dwarfs, 4 DB/DO white dwarfs, 13 subdwarf B stars, 12 subdwarf O stars, and 13 horizontal branch stars. The sample is analyzed using numerical convolution photometry.

  1. Astrometry and Photometry of Faint, High Priority Solar System Objects

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; Larsen, Jeffrey A.; Scotti, James V.; Bressi, Terrence H.; Maleszewski, Chester K.

    2014-02-01

    We propose to use MOSAIC 1.1 on the Mayall 4-meter telescope to improve knowledge of the orbits and magnitudes of high priority classes of Near Earth Objects (NEOs) and other small solar system bodies that cannot be reached with our Spacewatch telescopes. Many asteroids and comets are being lost owing to insufficient followup astrometry, but only the most important ones can continue to be observed with the limited resources available. Objects flagged as high scientific priority and urgently in need of further observations include freshly discovered virtual impactors (VIs) and NEOs discovered by the soon-to-be reactivated WISE spacecraft. It is better to follow objects longer during their discovery apparitions than to search tens of degrees of arc for them when they return years later, hence our need to reach fainter magnitudes. Other targets for recovery include future targets of radar, NEOs previously detected by WISE with orbits or albedos suggesting potential for cometary activity, potential destinations for spacecraft, and returning NEOs with hard-won albedos and diameters previously determined by WISE in need of astrometry.

  2. On the Automated and Objective Detection of Emission Lines in Faint-Object Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hong, Sungryong; Dey, Arjun; Prescott, Moire K. M.

    2014-11-01

    Modern spectroscopic surveys produce large spectroscopic databases, generally with sizes well beyond the scope of manual investigation. The need arises, therefore, for an automated line detection method with objective indicators for detection significance. In this paper, we present an automated and objective method for emission line detection in spectroscopic surveys and apply this technique to observed spectra from a Lyα emitter survey at z ~ 2.7, obtained with the Hectospec spectrograph on the MMT Observatory (MMTO). The basic idea is to generate on-source (signal plus noise) and off-source (noise only) mock observations using Monte Carlo simulations, and calculate completeness and reliability values, (C,R), for each simulated signal. By comparing the detections from real data with the Monte Carlo results, we assign the completeness and reliability values to each real detection. From 1574 spectra, we obtain 881 raw detections and, by removing low reliability detections, we finalize 652 detections from an automated pipeline. Most of high completeness and reliability detections, (C,R) ≈ (1.0,1.0), are robust detections when visually inspected; the low C and R detections are also marginal on visual inspection. This method of detecting faint sources is dependent on the accuracy of the sky subtraction.

  3. Astrometry and Photometry of Faint, High Priority Solar System Objects

    NASA Astrophysics Data System (ADS)

    McMillan, Robert S.; Larsen, Jeff; Scotti, Jim; Bressi, Terry; Spahr, Tim; Maleszewski, Chet

    2014-08-01

    We request MOSAIC 1.1 on the Mayall 4-meter telescope to improve knowledge of the orbits and magnitudes of high priority classes of Near Earth Objects (NEOs) and other small solar system bodies that cannot be reached with our Spacewatch telescopes. Targets include freshly discovered virtual impactors (VIs), other close approachers, and NEOs discovered by the NEOWISE spacecraft. It is better to follow objects longer during their discovery apparitions than to search tens of degrees of arc for them when they return years later, hence the need to reach fainter magnitudes on short notice. About half of our targets are therefore unknown at the time of this proposal. Other targets for recovery include future targets of radar, NEOs previously detected by WISE with orbits or albedos suggesting potential for cometary activity, potential destinations for spacecraft, and returning NEOs with hard-won albedos and diameters determined by WISE that need astrometry. Our past use of the Mayall telescope has been determined by Co-Investigator Tim Spahr of the Minor Planet Center to provide ``dramatic improvement'' to orbits.

  4. A Faint Near-Infrared Counterpart to the AXP 1E 2259+58.6

    NASA Technical Reports Server (NTRS)

    Hulleman, F.; Tennant, Allyn F., Jr.; vanKerkwijk, M. H.; Kulkarni, S. R.; Kouveliotou, C.; Patel, S. K.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    We present near-infrared and optical observations of the field of the Anomalous X-ray Pulsar 1E 2259+58.6 taken with the Keck telescope. We derive a subarcsecond Chandra position and tie it to our optical reference frame using other stars in the field. We find a very faint source, K(s) = 21.7 +/- 0.2 mag, with a position coincident with the Chandra position. We argue that this is the counterpart. In the J, I, and R bands, we derive (two sigma) limits of 23.8, 25.6 and 26.4mag, respectively. As with 4U 0142+61, for which a similarly faint counterpart was found, our results are inconsistent with models in which the source is powered by accretion from a disk. The only model that is not inconsistent, appears to be that in which 1E 2259+58.6 is a magnetar.

  5. Hubble Space Telescope Faint Object Camera calculated point-spread functions.

    PubMed

    Lyon, R G; Dorband, J E; Hollis, J M

    1997-03-10

    A set of observed noisy Hubble Space Telescope Faint Object Camera point-spread functions is used to recover the combined Hubble and Faint Object Camera wave-front error. The low-spatial-frequency wave-front error is parameterized in terms of a set of 32 annular Zernike polynomials. The midlevel and higher spatial frequencies are parameterized in terms of set of 891 polar-Fourier polynomials. The parameterized wave-front error is used to generate accurate calculated point-spread functions, both pre- and post-COSTAR (corrective optics space telescope axial replacement), suitable for image restoration at arbitrary wavelengths. We describe the phase-retrieval-based recovery process and the phase parameterization. Resultant calculated precorrection and postcorrection point-spread functions are shown along with an estimate of both pre- and post-COSTAR spherical aberration. PMID:18250862

  6. The Search for Faint Infrared Calibration Standards - Extending Landolt's Standards to V=19

    NASA Astrophysics Data System (ADS)

    Kidger, M.; González-Pérez, J. N.; Martín-Luis, F.; Cohen, M.

    ISO has shown the need to obtain a reliable calibration network of good pedigree to permit data from a wide range of instruments, covering an enormous wavelength range, to be calibrated on a consistent scale. We describe the first results of a programme to extend the Landolt calibration standards to at least V=19. At the same time we calibrate into the near-infrared JHK bands and measure fields separated from the celestial equator. This programme is one of several coordinated efforts to find faint type AV and KIII stars suitable for the mid-IR calibration of the Spanish 10-m Gran Telescopio Canarias (GTC). We have obtained a total of 34 712 measurements of 373 stars in 26 quasar fields between Declination -30o and +70o, calculating magnitudes with high precision in the visible and near-infrared (UBVRIJHK). We describe the results obtained and the characteristics of the sample of stars. The typical error on the magnitude in a single band is <1%, including all error sources. Very few candidate type AV or KIII stars are found, either in our sample, or amongst the fainter Landolt stars. We conclude that both samples are increasingly dominated by local dwarfs at increasingly faint magnitudes. We discuss the implications for taking mid-infrared calibration to the increasingly faint limits required by post-ISO instrumentation. The next steps in this project will be: -- To increase significantly the number of fields covered to ˜40. -- To take additional observations of all poorly covered fields and to add JHK data where none is available. -- To use our existing database to extend Landolt photometry of Selected Areas to include many stars not previously measured. -- To assign a spectral type to all candidate KIII and AV stars in our sample.

  7. FAME Astrometry of Faint Objects and the Kinematics of the Galaxy

    NASA Astrophysics Data System (ADS)

    Salim, S.; Gould, A.; Olling, R.

    2001-12-01

    We explore what the Full-Sky Astrometric Mapping Explorer (FAME) can achieve by observing a ``small'' (< 106) sample of faint objects (R< ~18) in addition to its standard R<15 magnitude limited catalog of 40x 106 stars. Observing some 50,000 quasars will improve the accuracy of the reference frame from 16 micro-as/yr to 6 micro-as/yr, allowing proper motion of the Galactic center due to reflex of the Sun's motion to be determined with an accuracy of 0.1%. It will also permit very accurate proper motions of the Magellanic Clouds. Quasar observations also offer a powerful check on any unmodeled parallax systematics. Proper motions of 30,000 faint field blue horizontal branch stars will allow stellar halo rotation to be mapped to beyond 35 kpc. Halo substructures producing clumps in the velocity space will be detectable to 10 kpc. In addition to this, allowing inclusion of objects with R>15 will increase the number of good parallaxes of late M-dwarfs 30-fold, and provide distances of over 200 L-dwarfs. FAME could obtain good (10%) parallaxes for 3700 white dwarfs, a 10-fold increase over the R<15 sample. These parallaxes will yield precise mass and luminosity functions. Candidate quasars, BHB stars, and nearby stars will be selected from existing and planned surveys (SDSS, USNO, 2MASS, etc.) The total number of faint candidates should be about 500,000, a small fraction of the FAME input catalog.

  8. Rocket instrument for far-UV spectrophotometry of faint astronomical objects.

    PubMed

    Hartig, G F; Fastie, W G; Davidsen, A F

    1980-03-01

    A sensitive sounding rocket instrument for moderate (~10-A) resolution far-UV (lambda1160-lambda1750-A) spectrophotometry of faint astronomical objects has been developed. The instrument employs a photon-counting microchannel plate imaging detector and a concave grating spectrograph behind a 40-cm Dall-Kirkham telescope. A unique remote-control pointing system, incorporating an SIT vidicon aspect camera, two star trackers, and a tone-encoded command telemetry link, permits the telescope to be oriented to within 5 arc sec of any target for which suitable guide stars can be found. The design, construction, calibration, and flight performance of the instrument are discussed. PMID:20220923

  9. Spectral evolution of galaxies. III - Cosmological predictions for the Space Telescope faint object camera

    NASA Astrophysics Data System (ADS)

    Bruzual A., G.

    1983-10-01

    The galactic spectral evolutionary models of Bruzual A. (1981) are employed to estimate parameters which will be observable by the wide-field camera and faint-object camera of the Space Telescope. The capabilities and bandpasses of the instruments are reviewed, and the results are presented in tables and graphs. Parameters calculated include the amplitude of the Lyman discontinuity at 912 A, stellar and galaxy rest-frame colors, color evolution, two-color diagrams as a function of redshift, luminosity evolution, surface brightness profiles, galaxy counts, and color and redshift distributions. In general, it is predicted that the space measurements will follow the trends noted in round-based observations.

  10. In-flight performance of the Faint Object Camera of the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Greenfield, P.; Paresce, F.; Baxter, D.; Hodge, P.; Hook, R.; Jakobsen, P.; Jedrzejewski, R.; Nota, A.; Sparks, W. B.; Towers, N.

    1991-01-01

    An overview of the Faint Object Camera and its performance to date is presented. In particular, the detector's efficiency, the spatial uniformity of response, distortion characteristics, detector and sky background, detector linearity, spectrography, and operation are discussed. The effect of the severe spherical aberration of the telescope's primary mirror on the camera's point spread function is reviewed, as well as the impact it has on the camera's general performance. The scientific implications of the performance and the spherical aberration are outlined, with emphasis on possible remedies for spherical aberration, hardware remedies, and stellar population studies.

  11. Rocket instrument for far-UV spectrophotometry of faint astronomical objects

    NASA Technical Reports Server (NTRS)

    Hartig, G. F.; Fastie, W. G.; Davidsen, A. F.

    1980-01-01

    A sensitive sounding rocket instrument for moderate (about 10-A) resolution far-UV (1160-1750-A) spectrophotometry of faint astronomical objects has been developed. The instrument employes a photon-counting microchannel plate imaging detector and a concave grating spectrograph behind a 40-cm Dall-Kirkham telescope. A unique remote-control pointing system, incorporating an SIT vidicon aspect camera, two star trackers, and a tone-encoded command telemetry link, permits the telescope to be oriented to within 5 arc sec of any target for which suitable guide stars can be found. The design, construction, calibration, and flight performance of the instrument are discussed.

  12. The ISON international campaigns for monitoring of faint high altitude objects

    NASA Astrophysics Data System (ADS)

    Molotov, Igor; Agapov, Vladimir; Rumyantsev, Vasiliy; Biryukov, Vadim; Schildknecht, Thomas; Bakhtigaraev, Nail; Ibrahimov, Mansur; Papushev, Pavel; Minikulov, Nasredin; Andrievsky, Sergei

    The research of the space debris fragments at high orbits is one of the main directions of the International Scientific Optical Network (ISON) activities. Therefore the dedicated ISON subsystem for high altitude faint space debris observations is arranged with the aim of detection and continuous tracking of as large number of unknown high altitude faint objects as possible. The subsystem includes the number of large telescopes that are able to detect the objects down to 20m-21m and the middle-size telescopes for the observations of the space objects of 15m-18m. The 1-m ZIMLAT in Zimmerwald, Switzerland, 1.5-m AZT-33IK in Mondy, Siberia, 64-cm AT- 64 in Nauchniy, Crimea, 60-cm RK-600 in Mayaki near Odessa, Ukraine, 60-cm Zeiss-600 in Maidanak, Uzbekistan, 70-cm AZT-8 in Gissar, Tajikistan are regularly participating in ISON observing campaigns in collaboration with 1-m Zeiss-1000 ESA space debris telescope in Teide, Canaries islands. 2.6-m ZTSh in Nauchniy, Crimea, 2-m Zeiss-2000 in Terskol, North Caucasus, 1-m Zeiss-1000 in Simeiz, Crimea, 1-m Zeiss-1000 in Arkhyz, North Caucasus are joining during few nights per month. The 60-cm Zeiss-600 in Arkhyz, 70-cm AZT-8 in Evpatoria, Crimea, 60-cm Zeiss-600 in Tarija, Bolivia, 80-cm RK-800 in Mayaki, 80-cm K-800 in Terskol, 50-cm in Ussuriysk, Far East will be added to the subsystem during 2008. The observing campaigns are coordinates by the Center on space debris data collection, processing and analysis of the KIAM RAS in cooperation with the AIUB space debris team. 353 faint objects are discovered in GEO region surveys during the last 3 years (about 100000 measurements were collected for this time), including objects with high AMR. Results are publishing monthly by KIAM in High Geocentric Orbit Space Debris Circular. We will discuss the most interesting of obtained results. Many of discovered fragments are associated with space debris clouds appeared as a result of known or suspected fragmentations occurred in GEO region

  13. VizieR Online Data Catalog: Faint Blue Objects at High Galactic Latitude (Warnock+ 1982)

    NASA Astrophysics Data System (ADS)

    Warnock, A., III; Usher, P. D.

    1995-05-01

    The data set of Faint Blue Objects at High Galactic Latitude is a catalog of objects selected according to relative ultraviolet excess from ubv three-color 1.2-m Palomar Schmidt plates. Five selected area fields centered on SA28, SA29, SA55, SA57 and SA94 are included. The data consist of color classifications, B magnitudes, 1950 equatorial coordinates and remarks; the current file contains 3678 objects. Three selected area fields were included originally, centered on SA57 (Usher 1981), SA29 (Usher, Mattson and Warnock 1982) and SA28 (Usher and Mitchell 1982). Areas centered on SA55 and SA94 were added in 1984. (1 data file).

  14. Faint quasi-stellar-object candidates in selected areas 28 and 68 identified from multicolor photometry

    SciTech Connect

    Shields, J.C.; Koo, D.C.; Kron, R.C.; California Univ., Berkeley; Lick Observatory, Santa Cruz, CA; Yerkes Observatory, Williams Bay, WI )

    1989-04-01

    Forty-five QSO candidates over a total area of 0.53 square degree in two fields at high Galactic latitudes have been identified. These candidates reached B of about 21.5 for field Lynx.3 in SA 28 and B of about 22 for field SA68.2, and were selected from a subset of objects in catalogs generated from multicolor photometry (UBV) of deep Kitt Peak 4-m plates with limits of B of about 24. This subset consists of all objects which appeared stellar-like in size but which did not have the UBV colors of common Galactic stars. Besides several probable high-redshift QSOs, this study yields faint QSO counts consistent with those from other surveys, and thus provides further support to models that include mainly the luminosity evolution of QSOs. 29 refs.

  15. Hubble Space Telescope: Faint object camera instrument handbook. Version 2.0

    NASA Technical Reports Server (NTRS)

    Paresce, Francesco (Editor)

    1990-01-01

    The Faint Object Camera (FOC) is a long focal ratio, photon counting device designed to take high resolution two dimensional images of areas of the sky up to 44 by 44 arcseconds squared in size, with pixel dimensions as small as 0.0007 by 0.0007 arcseconds squared in the 1150 to 6500 A wavelength range. The basic aim of the handbook is to make relevant information about the FOC available to a wide range of astronomers, many of whom may wish to apply for HST observing time. The FOC, as presently configured, is briefly described, and some basic performance parameters are summarized. Also included are detailed performance parameters and instructions on how to derive approximate FOC exposure times for the proposed targets.

  16. Hubble Space Telescope faint object camera instrument handbook (Post-COSTAR), version 5.0

    NASA Technical Reports Server (NTRS)

    Nota, A. (Editor); Jedrzejewski, R. (Editor); Greenfield, P. (Editor); Hack, W. (Editor)

    1994-01-01

    The faint object camera (FOC) is a long-focal-ratio, photon-counting device capable of taking high-resolution two-dimensional images of the sky up to 14 by 14 arc seconds squared in size with pixel dimensions as small as 0.014 by 0.014 arc seconds squared in the 1150 to 6500 A wavelength range. Its performance approaches that of an ideal imaging system at low light levels. The FOC is the only instrument on board the Hubble Space Telescope (HST) to fully use the spatial resolution capabilities of the optical telescope assembly (OTA) and is one of the European Space Agency's contributions to the HST program.

  17. The optical-infrared colour distribution of a statistically complete sample of faint field spheroidal galaxies

    NASA Astrophysics Data System (ADS)

    Menanteau, F.; Ellis, R. S.; Abraham, R. G.; Barger, A. J.; Cowie, L. L.

    1999-10-01

    In hierarchical models, where spheroidal galaxies are primarily produced via a continuous merging of disc galaxies, the number of intrinsically red systems at faint limits will be substantially lower than in `traditional' models where the bulk of star formation was completed at high redshifts. In this paper we analyse the optical-near-infrared colour distribution of a large flux-limited sample of field spheroidal galaxies identified morphologically from archival Hubble Space Telescope data. The I_814-HK' colour distribution for a sample jointly limited at I_814<23mag and HK'<19.5mag is used to constrain their star formation history. We compare visual and automated methods for selecting spheroidals from our deep HST images and, in both cases, detect a significant deficit of intrinsically red spheroidals relative to the predictions of high-redshift monolithic-collapse models. However, the overall space density of spheroidals (irrespective of colour) is not substantially different from that seen locally. Spectral synthesis modelling of our results suggests that high-redshift spheroidals are dominated by evolved stellar populations polluted by some amount of subsidiary star formation. Despite its effect on the optical-infrared colour, this star formation probably makes only a modest contribution to the overall stellar mass. We briefly discuss the implications of our results in the context of earlier predictions based on models where spheroidals assemble hierarchically.

  18. Improving the ability of image sensors to detect faint stars and moving objects using image deconvolution techniques.

    PubMed

    Fors, Octavi; Núñez, Jorge; Otazu, Xavier; Prades, Albert; Cardinal, Robert D

    2010-01-01

    In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the case of orbital objects, the deconvolution technique can double the signal-to-noise ratio of the image, which helps to discover and control dangerous objects as space debris or lost satellites. The benefits obtained using CCD detectors can be extrapolated to any kind of image sensors. PMID:22294896

  19. Improving the Ability of Image Sensors to Detect Faint Stars and Moving Objects Using Image Deconvolution Techniques

    PubMed Central

    Fors, Octavi; Núñez, Jorge; Otazu, Xavier; Prades, Albert; Cardinal, Robert D.

    2010-01-01

    In this paper we show how the techniques of image deconvolution can increase the ability of image sensors as, for example, CCD imagers, to detect faint stars or faint orbital objects (small satellites and space debris). In the case of faint stars, we show that this benefit is equivalent to double the quantum efficiency of the used image sensor or to increase the effective telescope aperture by more than 30% without decreasing the astrometric precision or introducing artificial bias. In the case of orbital objects, the deconvolution technique can double the signal-to-noise ratio of the image, which helps to discover and control dangerous objects as space debris or lost satellites. The benefits obtained using CCD detectors can be extrapolated to any kind of image sensors. PMID:22294896

  20. Statistical Track-Before-Detect Methods Applied to Faint Optical Observations of Resident Space Objects

    NASA Astrophysics Data System (ADS)

    Fujimoto, K.; Yanagisawa, T.; Uetsuhara, M.

    Automated detection and tracking of faint objects in optical, or bearing-only, sensor imagery is a topic of immense interest in space surveillance. Robust methods in this realm will lead to better space situational awareness (SSA) while reducing the cost of sensors and optics. They are especially relevant in the search for high area-to-mass ratio (HAMR) objects, as their apparent brightness can change significantly over time. A track-before-detect (TBD) approach has been shown to be suitable for faint, low signal-to-noise ratio (SNR) images of resident space objects (RSOs). TBD does not rely upon the extraction of feature points within the image based on some thresholding criteria, but rather directly takes as input the intensity information from the image file. Not only is all of the available information from the image used, TBD avoids the computational intractability of the conventional feature-based line detection (i.e., "string of pearls") approach to track detection for low SNR data. Implementation of TBD rooted in finite set statistics (FISST) theory has been proposed recently by Vo, et al. Compared to other TBD methods applied so far to SSA, such as the stacking method or multi-pass multi-period denoising, the FISST approach is statistically rigorous and has been shown to be more computationally efficient, thus paving the path toward on-line processing. In this paper, we intend to apply a multi-Bernoulli filter to actual CCD imagery of RSOs. The multi-Bernoulli filter can explicitly account for the birth and death of multiple targets in a measurement arc. TBD is achieved via a sequential Monte Carlo implementation. Preliminary results with simulated single-target data indicate that a Bernoulli filter can successfully track and detect objects with measurement SNR as low as 2.4. Although the advent of fast-cadence scientific CMOS sensors have made the automation of faint object detection a realistic goal, it is nonetheless a difficult goal, as measurements

  1. Astrometric and Photometric Follow-Up of Faint Near Earth Objects

    NASA Technical Reports Server (NTRS)

    Spahr, Timothy

    2004-01-01

    During the last year, the Near-Earth Object (NEO) follow-up program at Mt. Hopkins funded by the Near-Earth Object Observations (NEOO) program continued to improve. The Principal Investigator was again granted all the requested observing time. In addition to the requested time on the 4 8 in. telescope, 2 nights were also granted on the MMT for observations of extremely faint main-belt asteroids and NEOs. It is expected that the MMT can easily reach V = 25 over a 24 X 24 arcminute field of view. Improvements in the last year included more tweaks to the automatic astrometric routine for higher-quality astrometric fits. Use of the new USNO-B1.0 reference catalog has allowed the PI to push the average RMS of reference star solutions below 0.2 in.. Shift-and- stack techniques are used to improve the signal-to-noise ratio of the target objects. The 48 in. telescope at Mt. Hopkins is completely automated, and can be run remotely from either the Principal Investigator's office at SAO, or even his study at home. Most observing runs are now done remotely.

  2. Robotic telescope systems for CCD photometry of faint objects in crowded fields

    NASA Astrophysics Data System (ADS)

    Baruch, John E.; da Luz Vieira, Janice

    1993-11-01

    This paper first considers the design of robotic telescopes to monitor faint objects in crowded fields. It shows that the mechanical design problems have been solved by the use of precision control and modelling software developed for the latest large telescopes. Modern design methods mean that these telescopes can be produced relatively cheaply. The largest part of the cost of a robotic telescope is the software to enable it to work as an autonomous robot. Conventional software techniques are inadequate and inefficient for many purposes associated with robotic operation. These include: to optimize and monitor their operation and efficiency, to schedule their observing, to evaluate their environment, to generate confidence in the target acquisition pattern recognition parameters, to evaluate the quality of the CCD images and the photometry of the objects within the images, and to return reduced data to the astronomer with the required indices to gives the astronomer confidence in the data. The paper evaluates AI, neural nets and fuzzy logic techniques applied to these different problems.

  3. Track-Before-Detect Algorithm for Faint Moving Objects based on Random Sampling and Consensus

    NASA Astrophysics Data System (ADS)

    Dao, P.; Rast, R.; Schlaegel, W.; Schmidt, V.; Dentamaro, A.

    2014-09-01

    There are many algorithms developed for tracking and detecting faint moving objects in congested backgrounds. One obvious application is detection of targets in images where each pixel corresponds to the received power in a particular location. In our application, a visible imager operated in stare mode observes geostationary objects as fixed, stars as moving and non-geostationary objects as drifting in the field of view. We would like to achieve high sensitivity detection of the drifters. The ability to improve SNR with track-before-detect (TBD) processing, where target information is collected and collated before the detection decision is made, allows respectable performance against dim moving objects. Generally, a TBD algorithm consists of a pre-processing stage that highlights potential targets and a temporal filtering stage. However, the algorithms that have been successfully demonstrated, e.g. Viterbi-based and Bayesian-based, demand formidable processing power and memory. We propose an algorithm that exploits the quasi constant velocity of objects, the predictability of the stellar clutter and the intrinsically low false alarm rate of detecting signature candidates in 3-D, based on an iterative method called "RANdom SAmple Consensus” and one that can run real-time on a typical PC. The technique is tailored for searching objects with small telescopes in stare mode. Our RANSAC-MT (Moving Target) algorithm estimates parameters of a mathematical model (e.g., linear motion) from a set of observed data which contains a significant number of outliers while identifying inliers. In the pre-processing phase, candidate blobs were selected based on morphology and an intensity threshold that would normally generate unacceptable level of false alarms. The RANSAC sampling rejects candidates that conform to the predictable motion of the stars. Data collected with a 17 inch telescope by AFRL/RH and a COTS lens/EM-CCD sensor by the AFRL/RD Satellite Assessment Center is

  4. First results from the faint object camera - High-resolution imaging of the Pluto-Charon system

    NASA Technical Reports Server (NTRS)

    Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Crane, P.

    1991-01-01

    The first observations of a solar system target with the Faint Object Camera of the HST are reported. Observations of the Pluto-Charon system were obtained in f/96 and f/288 mode. Pluto and Charon were clearly resolved, and the observed separation and diameters are in accordance with expectations. The f/96 data were astrometrically and photometrically analyzed; preliminary results are presented.

  5. Correction of the geomagnetically induced image motion problem on the Hubble Space Telescope's Faint Object Spectrograph

    NASA Astrophysics Data System (ADS)

    Fitch, John E.; Hartig, George F.; Beaver, Edward A.; Hier, Richard G.

    1993-11-01

    During the Science Verification phase of the Hubble Space Telescope mission, it was determined that the Faint Object Spectrograph's (FOS) Red detector displayed significant image motions which correlated with orbital changes in the geomagnetic field. The Blue detector exhibited similar but less pronounced motions. The cause of this motion was determined to be inadequate magnetic shielding of the instrument's Digicon detectors. The results of these motions were decreases in onboard target acquisition accuracy, spectral resolution, and photometric accuracy. The Space Telescope Science Institute and the FOS Investigation Definition Team, set about correcting this Geomagnetically-induced Image Motion Problem (GIMP) through a real-time on-board correction scheme. This correction required modifications to almost all aspects of the HST ground system as well as additional NSSC1 flight software and the use of an existing software 'hook' in the FOS microprocessor firmware. This paper presents a detailed description of the problem, the proposed solution, and results of on-orbit testing of the correction mechanism.

  6. Faint Object Camera observations of M87 - The jet and nucleus

    NASA Technical Reports Server (NTRS)

    Boksenberg, A.; Macchetto, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.; Kamperman, T. M.

    1992-01-01

    UV and optical images of the central region and jet of the nearby elliptical galaxy M87 have been obtained with about 0.1 arcsec resolution in several spectral bands with the Faint Object Camera (FOC) on the HST, including polarization images. Deconvolution enhances the contrast of the complex structure and filamentary patterns in the jet already evident in the aberrated images. Morphologically there is close similarity between the FOC images of the extended jet and the best 2-cm radio maps obtained at similar resolution, and the magnetic field vectors from the UV and radio polarimetric data also correspond well. We observe structure in the inner jet within a few tenths arcsec of the nucleus which also has been well studied at radio wavelengths. Our UV and optical photometry of regions along the jet shows little variation in spectral index from the value 1.0 between markedly different regions and no trend to a steepening spectrum with distance along the jet.

  7. First results from the Faint Object Camera - Imaging the core of R Aquarii

    NASA Technical Reports Server (NTRS)

    Paresce, F.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.

    1991-01-01

    The Faint Object Camera on the HST was pointed toward the symbiotic long-period M7e Mira variable R Aquarii, and very high resolution images of the inner core, mainly in the ionized oxygen emission lines in the optical, are reported. Both images show bright arcs, knots, and filaments superposed on a fainter, diffuse nebulosity extending in a general SW-NE direction from the variable to the edge of the field at 10 arcsec distance. The core is resolved in forbidden O III 5007 A and forbidden O II 3727 A into at least two bright knots of emission whose positions and structures are aligned with PA = 50 deg. The central knots appear to be the source of a continuous, well-collimated, stream of material extending out to 3-4 arcsec in the northern sector corresponding to a linear distance of about 1000 AU. The northern stream seems to bend around an opaque obstacle and form a spiral before breaking up into wisps and knots. The southern stream is composed of smaller, discrete parcels of emitting gas curving to the SE.

  8. Constraints to the Cold Classical KBO population from HST observations of faint objects

    NASA Astrophysics Data System (ADS)

    Penteado, Paulo F.; Trilling, David; Grundy, William

    2015-11-01

    The size distribution of the known Kuiper Belt Objects has been described by a double power law, with a break at R magnitude 25. There are two leading interpretations to this break: 1) It is the result of the collisional evolution among these KBOs, with the objects smaller than the break being the population most affected by collisional erosion. 2) The size distribution break is primordial, set during the Kuiper Belt formation.The low inclination Kuiper Belt Objects, the Cold Classical population, is thought to have been dynamically isolated since the formation of the Solar System, and thus only collisions between Cold Classicals would have affected their size distribution. If the size distribution is collisional, it probes parameters of the Kuiper Belt history: strengths of the bodies, impact energies and frequency, and the the number of objects. If the distribution is primordial, it reveals parameters of the Kuiper Belt accretion, as well as limits on its subsequent collisional history.In this work, we obtained new HST observations of 5 faint Cold Classicals, which we combine with previous HST observations, to examine the distribution of two properties of the smallest KBOs: colors and binary fraction. These two properties can differentiate between a primordial and a collisional origin of the size distribution break. If the smaller bodies have been through extensive collisional evolution, they will have exposed materials from their interiors, which has not been exposed to weathering, and thus should be bluer than the old surfaces of the larger bodies. An independent constraint can be derived from the fraction of binary objects: the angular momentum of the observed binaries is typically too high to result from collisions, thus a collisionally-evolved population would have a lower binary fraction, due to the easier separation of binaries, compared to the disruption of similar-sized bodies, and the easier disruption of the binary components, due to the smaller size

  9. Hubble Space Telescope: Faint object spectrograph instrument handbook. Version 1.1

    NASA Technical Reports Server (NTRS)

    Ford, Holland C. (Editor)

    1990-01-01

    The Faint Object Spectrograph (FOS) has undergone substantial rework since the 1985 FOS Instrument Handbook was published, and we are now more knowledgeable regarding the spacecraft and instrument operations requirements and constraints. The formal system for observation specification has also evolved considerably, as the GTO programs were defined in detail. This supplement to the FOS Instrument Handbook addresses the important aspects of these changes, to facilitate proper selection and specification of FOS observing programs. Since the Handbook was published, the FOS red detector has been replaced twice, first with the best available spare in 1985 (which proved to have a poor, and steadily degrading red response), and later with a newly developed Digicon, which exhibits a high, stable efficiency and a dark-count rate less than half that of its predecessors. Also, the FOS optical train was realigned in 1987-88 to eliminate considerable beam-vignetting losses, and the collimators were both removed and recoated for greater reflectivity. Following the optics and detector rework, the FOS was carefully recalibrated (although only ambient measurements were possible, so the far-UV characteristics could not be re-evaluated directly). The resulting efficiency curves, including improved estimates of the telescope throughput, are shown. A number of changes in the observing-mode specifications and addition of several optional parameters resulted as the Proposal Instructions were honed during the last year. Target-brightness limitations, which have only recently been formulated carefully, are described. Although these restrictions are very conservative, it is imperative that the detector safety be guarded closely, especially during the initial stages of flight operations. Restrictions on the use of the internal calibration lamps and aperture-illumination sources (TA LEDs), also resulting from detector safety considerations, are outlined. Finally, many changes have been made to

  10. Infrared-based object tracking

    NASA Astrophysics Data System (ADS)

    Gervais, Jon; Youngblood, Austin; Delashmit, Walter H.

    2009-05-01

    Often it is necessary to track moving objects on horizontal paths. Human error and the associated cost and dangers of using humans lead to a requirement to automate this task. The system presented here was designed, built and tested. The system uses an IR beacon and a microcontroller receiver/controller module. The design consists of a field programmable gate array (FPGA) based IR transmitter and a microcontroller based IR receiver/controller. The design consisted of two main parts, the transmitter (beacon) and the receiver/controller module. The receiver was implemented with a FPGA so that the characteristics of the beacon signal could be adjusted more quickly and with greater precision. The controller module was integrated with the receivers and detailed system integration tests were performed. Measurements were collected, recorded and analyzed.

  11. High-resolution imaging of the Pluto-Charon system with the Faint Object Camera of the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Albrecht, R.; Barbieri, C.; Adorf, H.-M.; Corrain, G.; Gemmo, A.; Greenfield, P.; Hainaut, O.; Hook, R. N.; Tholen, D. J.; Blades, J. C.

    1994-01-01

    Images of the Pluto-Charon system were obtained with the Faint Object Camera (FOC) of the Hubble Space Telescope (HST) after the refurbishment of the telescope. The images are of superb quality, allowing the determination of radii, fluxes, and albedos. Attempts were made to improve the resolution of the already diffraction limited images by image restoration. These yielded indications of surface albedo distributions qualitatively consistent with models derived from observations of Pluto-Charon mutual eclipses.

  12. Active galactic nuclei cores in infrared-faint radio sources. Very long baseline interferometry observations using the Very Long Baseline Array

    NASA Astrophysics Data System (ADS)

    Herzog, A.; Middelberg, E.; Norris, R. P.; Spitler, L. R.; Deller, A. T.; Collier, J. D.; Parker, Q. A.

    2015-06-01

    Context. Infrared-faint radio sources (IFRS) form a new class of galaxies characterised by radio flux densities between tenths and tens of mJy and faint or absent infrared counterparts. It has been suggested that these objects are radio-loud active galactic nuclei (AGNs) at significant redshifts (z ≳ 2). Aims: Whereas the high redshifts of IFRS have been recently confirmed based on spectroscopic data, the evidence for the presence of AGNs in IFRS is mainly indirect. So far, only two AGNs have been unquestionably confirmed in IFRS based on very long baseline interferometry (VLBI) observations. In this work, we test the hypothesis that IFRS contain AGNs in a large sample of sources using VLBI. Methods: We observed 57 IFRS with the Very Long Baseline Array (VLBA) down to a detection sensitivity in the sub-mJy regime and detected compact cores in 35 sources. Results: Our VLBA detections increase the number of VLBI-detected IFRS from 2 to 37 and provide strong evidence that most - if not all - IFRS contain AGNs. We find that IFRS have a marginally higher VLBI detection fraction than randomly selected sources with mJy flux densities at arcsec-scales. Moreover, our data provide a positive correlation between compactness - defined as the ratio of milliarcsec- to arcsec-scale flux density - and redshift for IFRS, but suggest a decreasing mean compactness with increasing arcsec-scale radio flux density. Based on these findings, we suggest that IFRS tend to contain young AGNs whose jets have not formed yet or have not expanded, equivalent to very compact objects. We found two IFRS that are resolved into two components. The two components are spatially separated by a few hundred milliarcseconds in both cases. They might be components of one AGN, a binary black hole, or the result of gravitational lensing.

  13. VizieR Online Data Catalog: Faint Blue Objects at High Galactic Latitude (Warnock+ 1982-1990)

    NASA Astrophysics Data System (ADS)

    Warnock, A., III; Usher, P. D.

    2007-02-01

    The data set of Faint Blue Objects at High Galactic Latitude is a catalog of objects selected according to relative ultraviolet excess from ubv three-color 1.2-m Palomar Schmidt plates. Five selected area fields centered on SA28, SA29, SA55, SA57 and SA94 are included. The data consist of color classifications, B magnitudes, 1950 equatorial coordinates and remarks; the current file contains 3678 objects. Three selected area fields were included originally, centered on SA57 (Usher 1981), SA29 (Usher, Mattson and Warnock 1982) and SA28 (Usher and Mitchell 1982). Areas centered on SA55 and SA94 were added in 1984; areas centered on SA71 (Usher et al., Paper V, 1988ApJS...66....1U) and SA82 (Usher & Mitchell, Paper VI, 1990ApJS...74..885U) were added in 2007 by CDS. (1 data file).

  14. First results from the faint object camera - High-resolution observations of the central object R136 in the 30 Doradus nebula

    NASA Technical Reports Server (NTRS)

    Weigelt, G.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.; Kamperman, T. M.

    1991-01-01

    R136 is the luminous central object of the giant H II region 30 Doradus in the LMC. The first high-resolution observations of R136 with the Faint Object Camera on board the Hubble Space Telescope are reported. The physical nature of the brightest component R136a has been a matter of some controversy over the last few years. The UV images obtained show that R136a is a very compact star cluster consisting of more than eight stars within 0.7 arcsec diameter. From these high-resolution images a mass upper limit can be derived for the most luminous stars observed in R136.

  15. SELFI: an object-based, Bayesian method for faint emission line source detection in MUSE deep field data cubes

    NASA Astrophysics Data System (ADS)

    Meillier, Céline; Chatelain, Florent; Michel, Olivier; Bacon, Roland; Piqueras, Laure; Bacher, Raphael; Ayasso, Hacheme

    2016-04-01

    We present SELFI, the Source Emission Line FInder, a new Bayesian method optimized for detection of faint galaxies in Multi Unit Spectroscopic Explorer (MUSE) deep fields. MUSE is the new panoramic integral field spectrograph at the Very Large Telescope (VLT) that has unique capabilities for spectroscopic investigation of the deep sky. It has provided data cubes with 324 million voxels over a single 1 arcmin2 field of view. To address the challenge of faint-galaxy detection in these large data cubes, we developed a new method that processes 3D data either for modeling or for estimation and extraction of source configurations. This object-based approach yields a natural sparse representation of the sources in massive data fields, such as MUSE data cubes. In the Bayesian framework, the parameters that describe the observed sources are considered random variables. The Bayesian model leads to a general and robust algorithm where the parameters are estimated in a fully data-driven way. This detection algorithm was applied to the MUSE observation of Hubble Deep Field-South. With 27 h total integration time, these observations provide a catalog of 189 sources of various categories and with secured redshift. The algorithm retrieved 91% of the galaxies with only 9% false detection. This method also allowed the discovery of three new Lyα emitters and one [OII] emitter, all without any Hubble Space Telescope counterpart. We analyzed the reasons for failure for some targets, and found that the most important limitation of the method is when faint sources are located in the vicinity of bright spatially resolved galaxies that cannot be approximated by the Sérsic elliptical profile. The software and its documentation are available on the MUSE science web service (muse-vlt.eu/science).

  16. First results from the Edinburgh-Cape faint blue object survey - Normal stars at high galactic latitudes

    NASA Astrophysics Data System (ADS)

    Kilkenny, D.; O'Donoghue, D.; Stobie, R. S.

    1991-02-01

    A simple analysis using low-dispersion Reticon spectroscopy and Stromgren photometry is presented for a sample of 20 apparently normal early-type stars detected in the Edinburgh-Cape faint blue object survey of high galactic latitudes. Four stars are not normal, showing high gravity or helium abundance anomalies; 12 stars appear to be at moderate distances from the galactic plane and four stars have derived z-distances greater than about 5 kpc. The sample was selected from 33 survey fields completed to B = 16.5 mag and indicates that the total galactic population of 'very high-z' B stars is only of the order 100-1000. The Dyson and Hartquist (1983) model for the formation of such objects by cloudlet-cloudlet collisions within high-velocity clouds cannot therefore be ruled out on the basis of star formation rates.

  17. VizieR Online Data Catalog: Infrared-faint radio sources catalog (Collier+, 2014)

    NASA Astrophysics Data System (ADS)

    Collier, J. D.; Banfield, J. K.; Norris, R. P.; Schnitzeler, D. H. F. M.; Kimball, A. E.; Filipovic, M. D.; Jarrett, T. H.; Lonsdale, C. J.; Tothill, N. F. H.

    2014-11-01

    The 20cm radio data come from the Unified Radio Catalog (URC) compiled by Kimball & Ivezic (2008AJ....136..684K). This radio catalogue combines data from the National Radio Astronomy Observatory (NRAO) VLA Sky Survey (NVSS; Condon et al., 1998, Cat. VIII/65), Faint Images of the Radio Sky at Twenty Centimeters (FIRST; Becker, White & Helfand, 1995, cat. VIII/92), Green Bank 6cm survey (GB6; Gregory et al., 1996, Cat. VIII/40), the Westerbork Northern Sky Survey (WENSS; Rengelink et al. 1997; de Bruyn et al. 2000, Cat. VIII/62) and the Sloan Digital Sky Survey Data Release 6 (SDSS DR6; Adelman-McCarthy et al., 2008, Cat. II/282). We use updated NVSS and FIRST data from the URC version 2.0 (Kimball & Ivezic, in preparation), which includes a number of new sources as well as updated positions and flux densities. The IR data come from WISE (Wright et al. (WISE Team) 2009, Cat. II/311), which is an all-sky survey centred at 3.4, 4.6, 12 and 22um (referred to as bands W1, W2, W3 and W4), with respective angular resolutions of 6.1, 6.4, 6.5 and 12.0-arcsec (full width at half-maximum, FWHM), and typical 5σ sensitivity levels of 0.08, 0.11, 1 and 6mJy, with sensitivity increasing towards the ecliptic poles. (1 data file).

  18. Hubble Space Telescope Faint Object Spectrograph and ground-based observations of the broad absorption line quasar 0226-1024

    NASA Technical Reports Server (NTRS)

    Korista, Kirk T.; Weymann, Ray J.; Morris, Simon L.; Kopko, Michael, Jr.; Turnshek, David A.; Hartig, George F.; Foltz, Craig B.; Burbidge, E. M.; Junkkarinen, Vesa T.

    1992-01-01

    Faint Object Spectrograph data from the Hubble Space Telescope of the broad absorption line quasar 0226-1024 have revealed the presence of 8-10 absorbing ions between 680 and 1000 A (restframe): C III, N III, N IV, O III, O IV, O VI, S V, S VI, possibly Ne VIII, and possibly O V* arising from a metastable excited state. We also present ground-based optical observations of the broad line troughs for the following ions: H I, C IV, N V, Si IV, and possibly Fe III, S IV, P V, and C III* (also arising from a metastable excited state). The results of this fit are used to estimate the absorbing ionic column densities. There is evidence that the broad absorption line clouds are optically thick and either do not completely cover the continuum source or narrow unresolved lines are present.

  19. Faint blue objects at high Galactic latitude. V - Palomar Schmidt field centered on selected area 71

    NASA Technical Reports Server (NTRS)

    Usher, Peter D.; Mitchell, Kenneth J.; Warnock, Archibald, III

    1988-01-01

    Starlike objects with both blue and ultraviolet excess have been selected from a Palomar 1.2 m Schmidt field centered on Kapteyn selected area 71. The method of selection is that used in the previous papers of this series, but modified to account for the differential reddening that occurs across the field. The color classes, color subclasses, positions, and magnitudes of the selected objects are listed.

  20. An Automatic Technique for Finding Faint Moving Objects in Wide Field CCD Images

    NASA Astrophysics Data System (ADS)

    Hainaut, O. R.; Meech, K. J.

    1996-09-01

    The traditional method used to find moving objects in astronomical images is to blink pairs or series of frames after registering them to align the background objects. While this technique is extremely efficient in terms of the low signal-to-noise ratio that the human sight can detect, it proved to be extremely time-, brain- and eyesight-consuming. The wide-field images provided by the large CCD mosaic recently built at IfA cover a field of view of 20 to 30' over 8192(2) pixels. Blinking such images is an enormous task, comparable to that of blinking large photographic plates. However, as the data are available digitally (each image occupying 260Mb of disk space), we are developing a set of computer codes to perform the moving object identification in sets of frames. This poster will describe the techniques we use in order to reach a detection efficiency as good as that of a human blinker; the main steps are to find all the objects in each frame (for which we rely on ``S-Extractor'' (Bertin & Arnouts (1996), A&ASS 117, 393), then identify all the background objects, and finally to search the non-background objects for sources moving in a coherent fashion. We will also describe the results of this method applied to actual data from the 8k CCD mosaic. {This work is being supported, in part, by NSF grant AST 92-21318.}

  1. VizieR Online Data Catalog: Faint blue objects at high galactic latitude (Mitchell+, 2004)

    NASA Astrophysics Data System (ADS)

    Mitchell, K. J.; Usher, P. D.

    2006-11-01

    The US survey has cataloged 3987 objects in seven high Galactic latitude fields according to their optical colors, magnitudes, and morphologies using photographic techniques. This paper analyzes the effectiveness of the survey at producing finding lists for complete samples of hot stars and quasars that exhibit blue and/or ultraviolet excess (B-UVX) relative to the colors of halo F and G subdwarf stars. A table of 599 spectroscopic identifications summarizes the spectroscopic coverage of the US objects that has been accomplished to date. (6 data files).

  2. ALMA constraints on the faint millimetre source number counts and their contribution to the cosmic infrared background

    NASA Astrophysics Data System (ADS)

    Carniani, S.; Maiolino, R.; De Zotti, G.; Negrello, M.; Marconi, A.; Bothwell, M. S.; Capak, P.; Carilli, C.; Castellano, M.; Cristiani, S.; Ferrara, A.; Fontana, A.; Gallerani, S.; Jones, G.; Ohta, K.; Ota, K.; Pentericci, L.; Santini, P.; Sheth, K.; Vallini, L.; Vanzella, E.; Wagg, J.; Williams, R. J.

    2015-12-01

    We have analysed 18 ALMA continuum maps in Bands 6 and 7, with rms down to 7.8 μJy, to derive differential number counts down to 60 μJy and 100 μJy at λ = 1.3 mm and λ = 1.1 mm, respectively. Furthermore, the non-detection of faint sources in the deepest ALMA field enabled us to set tight upper limits on the number counts down to 30 μJy. This is a factor of four deeper than the currently most stringent upper limit. The area covered by the combined fields is 9.5 × 10-4 deg2 at 1.1 mm and 6.6 × 10-4 deg2 at 1.3 mm. With respect to previous works, we improved the source extraction method by requiring that the dimension of the detected sources be consistent with the beam size. This method enabled us to remove spurious detections that have plagued the purity of the catalogues in previous studies. We detected 50 faint sources (at fluxes <1 mJy) with signal-to-noise (S/N) >3.5 down to 60 μJy, hence improving the statistics by a factor of four relative to previous studies. The inferred differential number counts are dN/ d(Log10S) = 1 × 105 deg2 at a 1.1 mm flux Sλ = 1.1 mm = 130 μJy, and dN/ d(Log10S) = 1.1 × 105 deg2 at a 1.3 mm flux Sλ = 1.3 mm = 60 μJy. At the faintest flux limits probed by our data, i.e. 30 μJy and 40 μJy, we obtain upper limits on the differential number counts of dN/ d(Log10S) < 7 × 105 deg2 and dN/ d(Log10S) < 3 × 105 deg2, respectively. Determining the fraction of cosmic infrared background (CIB) resolved by the ALMA observations was hampered by the large uncertainties plaguing the CIB measurements (a factor of four in flux). However, our results provide a new lower limit to CIB intensity of 17.2 Jy deg-2 at 1.1 mm and of 12.9 Jy deg-2 at 1.3 mm. Moreover, the flattening of the integrated number counts at faint fluxes strongly suggests that we are probably close to the CIB intensity. Our data imply that galaxies with star formation rate (SFR) < 40 M⊙/yr certainly contribute less than 50% to the CIB (and probably a much lower

  3. Faint Blue Objects at High Galactic Latitude. VIII. Performance Characteristics of the US Survey

    NASA Astrophysics Data System (ADS)

    Mitchell, Kenneth J.; Usher, P. D.

    2004-07-01

    The US survey has cataloged 3987 objects in seven high Galactic latitude fields according to their optical colors, magnitudes, and morphologies using photographic techniques. This paper analyzes the effectiveness of the survey at producing finding lists for complete samples of hot stars and quasars that exhibit blue and/or ultraviolet excess (B-UVX) relative to the colors of halo F and G subdwarf stars. A table of 599 spectroscopic identifications summarizes the spectroscopic coverage of the US objects that has been accomplished to date. In addition, some of the survey plates have been reexamined for objects missed during the original selection, and the literature has been searched for all other spectroscopically identified blue stars and quasars with z<2.2 that have been selected by other surveys within the US survey areas. These results are used to estimate empirically both the accuracy of the US survey selection boundaries (in color, morphology, and brightness) and the completeness of the resulting samples of B-UVX US objects within those boundaries. In particular, it is shown that the reliability of the US color classifications is high and that the previously derived US morphological boundary for the complete selection of unresolved quasars is accurate. The contribution of color and morphological classification errors to B-UVX sample incompleteness is therefore correspondingly small. The empirical tests indicate high levels of completeness (95+1-2%) for the samples of US quasars and hot stars isolated within the stated survey selection limits. Errata and improvements to some of the published catalog data are presented in Appendices.

  4. Infrared-faint radio sources: a cosmological view. AGN number counts, the cosmic X-ray background and SMBH formation

    NASA Astrophysics Data System (ADS)

    Zinn, P.-C.; Middelberg, E.; Ibar, E.

    2011-07-01

    Context. Infrared-faint radio sources (IFRS) are extragalactic emitters clearly detected at radio wavelengths but barely detected or undetected at optical and infrared wavelengths, with 5σ sensitivities as low as 1 μJy. Aims: Spectral energy distribution (hereafter SED) modelling and analyses of their radio properties indicate that IFRS are consistent with a population of (potentially extremely obscured) high-redshift AGN at 3 ≤ z ≤ 6. We demonstrate some astrophysical implications of this population and compare them to predictions from models of galaxy evolution and structure formation. Methods: We compiled a list of IFRS from four deep extragalactic surveys and extrapolated the IFRS number density to a survey-independent value of (30.8 ± 15.0) deg-2. We computed the IFRS contribution to the total number of AGN in the Universe to account for the cosmic X-ray background. By estimating the black hole mass contained in IFRS, we present conclusions for the SMBH mass density in the early universe and compare it to relevant simulations of structure formation after the Big Bang. Results: The number density of AGN derived from the IFRS density was found to be ~310 deg-2, which is equivalent to a SMBH mass density of the order of 103 M⊙ Mpc-3 in the redshift range 3 ≤ z ≤ 6. This produces an X-ray flux of 9 × 10-16 W m-2 deg-2 in the 0.5-2.0 keV band and 3 × 10-15 W m-2 deg-2 in the 2.0-10 keV band, in agreement with the missing unresolved components of the Cosmic X-ray Background. To address SMBH formation after the Big Bang we invoke a scenario involving both halo gas accretion and major mergers.

  5. Faint CO Line Wings in Four Star-forming (Ultra)luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Leroy, Adam K.; Walter, Fabian; Decarli, Roberto; Bolatto, Alberto; Zschaechner, Laura; Weiss, Axel

    2015-09-01

    We report the results of a search for large velocity width, low-intensity line wings—a commonly used signature of molecular outflows—in four low redshift (ultra)luminous infrared galaxies that appear to be dominated by star formation. The targets were drawn from a sample of fourteen targets presented in Chung et al., who showed the stacked CO spectrum of the sample to exhibit 1000 km s-1-wide line wings. We obtained sensitive, wide bandwidth imaging of our targets using the IRAM Plateau de Bure Interferometer. We detect each target at very high significance but do not find the claimed line wings in these four targets. Instead, we constrain the flux in the line wings to be only a few percent. Casting our results as mass outflow rates following Cicone et al. we show them to be consistent with a picture in which very high mass loading factors preferentially occur in systems with high active galactic nucleus contributions to their bolometric luminosity. We identify one of our targets, IRAS 05083 (VII Zw 31), as a candidate molecular outflow.

  6. Imaging of four planetary nebulae in the Magellanic Clouds using the Hubble Space Telescope Faint Object Camera

    NASA Technical Reports Server (NTRS)

    Blades, J. C.; Barlow, M. J.; Albrecht, R.; Barbieri, C.; Boksenberg, A.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.; Kamperman, T. M.

    1992-01-01

    Using the Faint Object Camera on-board the Hubble Space Telescope, we have obtained images of four planetary nebulae (PNe) in the Magellanic Clouds, namely N2 and N5 in the SMC and N66 and N201 in the LMC. Each nebula was imaged through two narrow-band filters isolating forbidden O III 5007 and H-beta, for a nominal exposure time of 1000 s in each filter. In forbidden O III, SMC N5 shows a circular ring structure, with a peak-to-peak diameter of 0.26 arcsec and a FWHM of 0.35 arcsec while SMC N2 shows an elliptical ring structure with a peak-to-peak diameter of 0.26 x 0.21. The expansion ages corresponding to the observed structures in SMC N2 and N5 are of the order of 3000 yr. LMC N201 is very compact, with a FWHM of 0.2 arcsec in H-beta. The Type I PN LMC N66 is a multipolar nebula, with the brightest part having an extent of about 2 arcsec and with fainter structures extending over 4 arcsec.

  7. Object Cueing System For Infrared Images

    NASA Astrophysics Data System (ADS)

    Ranganath, H. S.; McIngvale, Pat; Speigle, Scott

    1987-09-01

    This paper considers the design of an object cueing system as a rule-based expert system. The architecture is modular and the control strategy permits dynamic scheduling of tasks. In this approach, results of several algorithms and many object recognition heuristics are combined to achieve better performance levels. Importance of spatial knowledge representatiOn is also discussed.

  8. [Calculation of infrared temperature measurement on non-Lambertian objects].

    PubMed

    Yang, Zhen; Zhang, Shi-cheng; Yang, Li

    2010-08-01

    According to the theory of infrared radiation and principles of temperature measurement using infrared imager, a universal mathematical model of infrared imager is established. Based on the normal emissivity characteristics of measured surface, the mathematical model is simplified, and the formula of temperature measurement using infrared imager is obtained. Through the relevant experiment, it is proved that the sum of emissivity and reflectivity of objects remained basically unchanged in a certain temperature range. The sum of emissivity and reflectivity of objects is relevant to the object types, surface conditions and the object temperature. The closer an object to Lambertian objects, the greater the sum is and the closer it is to 1. The farther the surface conditions deviate from the Lambertian surface, or the smoother the surface, the smaller the sum is. Experimental results show that if the object is close to Lambertian objects, it could be regarded as Lambertian, without the need for amendments to the actual objects. For non-Lambertian body (especially the smooth surfaces and low-emissivity objects), the amendment is necessary, or the temperature measurement error will increase, or even the obtained temperature is very far away from its true temperature. The study shows that, through the amendment, infrared temperature measurement on non-Lambertian objects is available. PMID:20939314

  9. Infrared system for monitoring movement of objects

    DOEpatents

    Valentine, K.H.; Falter, D.D.; Falter, K.G.

    1991-04-30

    A system is described for monitoring moving objects, such as the flight of honeybees and other insects, using a pulsed laser light source. This system has a self-powered micro-miniaturized transmitting unit powered, in the preferred embodiment, with an array of solar cells. This transmitting unit is attached to the object to be monitored. These solar cells provide current to a storage energy capacitor to produce, for example, five volts for the operation of the transmitter. In the simplest embodiment, the voltage on the capacitor operates a pulse generator to provide a pulsed energizing signal to one or more very small laser diodes. The pulsed light is then received at a receiving base station using substantially standard means which converts the light to an electrical signal for processing in a microprocessor to create the information as to the movement of the object. In the case of a unit for monitoring honeybees and other insects, the transmitting unit weighs less than 50 mg, and has a size no larger than 1[times]3[times]5 millimeters. Also, the preferred embodiment provides for the coding of the light to uniquely identify the particular transmitting unit that is being monitored. A wake-up' circuit is provided in the preferred embodiment whereby there is no transmission until the voltage on the capacitor has exceeded a pre-set threshold. Various other uses of the motion-detection system are described. 4 figures.

  10. Infrared system for monitoring movement of objects

    DOEpatents

    Valentine, Kenneth H.; Falter, Diedre D.; Falter, Kelly G.

    1991-01-01

    A system for monitoring moving objects, such as the flight of honeybees and other insects, using a pulsed laser light source. This system has a self-powered micro-miniaturized transmitting unit powered, in the preferred embodiment, with an array solar cells. This transmitting unit is attached to the object to be monitored. These solar cells provide current to a storage energy capacitor to produce, for example, five volts for the operation of the transmitter. In the simplest embodiment, the voltage on the capacitor operates a pulse generator to provide a pulsed energizing signal to one or more very small laser diodes. The pulsed light is then received at a receiving base station using substantially standard means which converts the light to an electrical signal for processing in a microprocessor to create the information as to the movement of the object. In the case of a unit for monitoring honeybees and other insects, the transmitting unit weighs less than 50 mg, and has a size no larger than 1.times.3.times.5 millimeters. Also, the preferred embodiment provides for the coding of the light to uniquely identify the particular transmitting unit that is being monitored. A "wake-up" circuit is provided in the preferred embodiment whereby there is no transmission until the voltage on the capacitor has exceeded a pre-set threshold. Various other uses of the motion-detection system are described.

  11. Fainting (Syncope)

    MedlinePlus

    ... Adults Making Your Wishes Known Home & Community Home › Aging & Health A to Z › Fainting (Syncope) Font size A A A Print Share Glossary Basic Facts & Information Causes & Symptoms Diagnosis & Tests Care & Treatment Lifestyle & Management Other Resources Caregiving How ...

  12. Infrared hyperspectral upconversion imaging using spatial object translation.

    PubMed

    Kehlet, Louis Martinus; Sanders, Nicolai; Tidemand-Lichtenberg, Peter; Dam, Jeppe Seidelin; Pedersen, Christian

    2015-12-28

    In this paper hyperspectral imaging in the mid-infrared wavelength region is realised using nonlinear frequency upconversion. The infrared light is converted to the near-infrared region for detection with a Si-based CCD camera. The object is translated in a predefined grid by motorized actuators and an image is recorded for each position. A sequence of such images is post-processed into a series of monochromatic images in a wavelength range defined by the phasematch condition and numerical aperture of the upconversion system. A standard USAF resolution target and a polystyrene film are used to impart spatial and spectral information unto the source. PMID:26832059

  13. Near-infrared spectroscopy of faint discrete X-ray point sources constituting the Galactic ridge X-ray emission

    NASA Astrophysics Data System (ADS)

    Morihana, Kumiko; Tsujimoto, Masahiro; Dubath, Pierre; Yoshida, Tessei; Suzuki, Kensuke; Ebisawa, Ken

    2016-08-01

    The Galactic Ridge X-ray Emission (GRXE) is an apparently extended X-ray emission along the Galactic plane. The X-ray spectrum is characterized by a hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (˜80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations; thus GRXE is mostly composed of dim Galactic X-ray point sources, at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out near-infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l, b) = (0.1°, -1.4°) and (28.5°, 0.0°) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as H I (Brγ), He I, and He II (2 objects), (B) soft X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (46 objects), and (C) hard X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (17 objects). From these features, we argue that class A sources are cataclysmic variables (CVs), and class B sources are late-type stars with enhanced coronal activity, which is in agreement with current knowledge. Class C sources possibly belong to a new group of objects, which has been poorly studied so far. We argue that the candidate sources for class C are the binary systems hosting white dwarfs and late-type companions with very low accretion rates. It is likely that this newly recognized class of sources contribute to a non-negligible fraction of the GRXE, especially in the Fe K band.

  14. Near-infrared spectroscopy of faint discrete X-ray point sources constituting the Galactic ridge X-ray emission

    NASA Astrophysics Data System (ADS)

    Morihana, Kumiko; Tsujimoto, Masahiro; Dubath, Pierre; Yoshida, Tessei; Suzuki, Kensuke; Ebisawa, Ken

    2016-05-01

    The Galactic Ridge X-ray Emission (GRXE) is an apparently extended X-ray emission along the Galactic plane. The X-ray spectrum is characterized by a hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (˜80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations; thus GRXE is mostly composed of dim Galactic X-ray point sources, at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out near-infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l, b) = (0.1°, -1.4°) and (28.5°, 0.0°) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as H I (Brγ), He I, and He II (2 objects), (B) soft X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (46 objects), and (C) hard X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (17 objects). From these features, we argue that class A sources are cataclysmic variables (CVs), and class B sources are late-type stars with enhanced coronal activity, which is in agreement with current knowledge. Class C sources possibly belong to a new group of objects, which has been poorly studied so far. We argue that the candidate sources for class C are the binary systems hosting white dwarfs and late-type companions with very low accretion rates. It is likely that this newly recognized class of sources contribute to a non-negligible fraction of the GRXE, especially in the Fe K band.

  15. THE OPTICAL SPECTRA OF SPITZER 24 mum GALAXIES IN THE COSMIC EVOLUTION SURVEY FIELD. II. FAINT INFRARED SOURCES IN THE zCOSMOS-BRIGHT 10k CATALOG

    SciTech Connect

    Caputi, K. I.; Lilly, S. J.; Maier, C.; Carollo, C. M.; Aussel, H.; Floc'h, E. Le; Frayer, D.; Contini, T.; Kneib, J.-P.; Le Fevre, O.; Mainieri, V.; Renzini, A.; Scodeggio, M.; Scoville, N.; Zamorani, G.; Bardelli, S.; Bolzonella, M.; Coppa, G.; Bongiorno, A.

    2009-12-20

    We have used the zCOSMOS-bright 10k sample to identify 3244 Spitzer/MIPS 24 mum-selected galaxies with 0.06 mJy < S{sub 24{sub m}}u{sub m} approx< 0.50 mJy and I{sub AB} < 22.5, over 1.5 deg{sup 2} of the COSMOS field, and studied different spectral properties, depending on redshift. At 0.2 < z < 0.3, we found that different reddening laws of common use in the literature explain the dust extinction properties of approx80% of our infrared (IR) sources, within the error bars. For up to 16% of objects, instead, the Halpha lambda6563/Hbeta lambda4861 ratios are too high for their IR/UV attenuations, which is probably a consequence of inhomogeneous dust distributions. In only a few of our galaxies at 0.2 < z < 0.3, the IR emission could be mainly produced by dust heated by old rather than young stars. Besides, the line ratios of approx22% of our galaxies suggest that they might be star-formation/nuclear-activity composite systems. At 0.5 < z < 0.7, we estimated galaxy metallicities for 301 galaxies: at least 12% of them are securely below the upper-branch mass-metallicity trend, which is consistent with the local relation. Finally, we performed a combined analysis of the H{sub d}elta equivalent width versus D{sub n} (4000) diagram for 1722 faint and bright 24 mum galaxies at 0.6 < z < 1.0, spanning two decades in mid-IR luminosity. We found that, while secondary bursts of star formation are necessary to explain the position of the most luminous IR galaxies in that diagram, quiescent, exponentially declining star formation histories can well reproduce the spectral properties of approx40% of the less luminous sources. Our results suggest a transition in the possible modes of star formation at total IR luminosities L{sub TIR} approx (3 +- 2) x 10{sup 11} L{sub sun}.

  16. Hubble Space Telescope faint object spectrograph Quasar Absorption System Snapshot Survey (AbSnap). 1: Astrometric optical positions and finding charts of 269 bright QSO

    NASA Technical Reports Server (NTRS)

    Bowen, David V.; Osmer, Samantha J.; Blades, J. Chris; Tytler, David; Cottrell, Lance; Fan, Xiao-Ming; Lanzetta, Kenneth M.

    1994-01-01

    We present finding charts and optical positions accurate to less than 1 arcsec for 269 bright (V less than or = 18.5) Quasi-Stellar Objects (QSOs). These objects were selected as candidates for the Hubble Space Telescope (HST) Quasar Absorption System Snapshot Survey (AbSnap), a program designed to use the Faint Object Spectrograph (FOS) to obtain short exposure ultraviolet (UV) spectra of bright QSOs. Many quasars were included because of their proximity to bright, low redshift galaxies and positions of these QSOs are measured accurately for the first time. Data were obtained using the digitized sky survey produced by the Space Telescope Science Institute's Guide Stars Selection System Astrometric Support Program.

  17. MID-INFRARED SPECTRAL VARIABILITY ATLAS OF YOUNG STELLAR OBJECTS

    SciTech Connect

    Kospal, A.; Abraham, P.; Kun, M.; Moor, A.; Acosta-Pulido, J. A.; Henning, Th.; Leinert, Ch.; Turner, N. J.

    2012-08-01

    Optical and near-infrared variability is a well-known property of young stellar objects. However, a growing number of recent studies claim that a considerable fraction of them also exhibit mid-infrared flux changes. With the aim of studying and interpreting variability on a decadal timescale, here we present a mid-infrared spectral atlas containing observations of 68 low- and intermediate-mass young stellar objects. The atlas consists of 2.5-11.6 {mu}m low-resolution spectra obtained with the ISOPHOT-S instrument on board the Infrared Space Observatory (ISO) between 1996 and 1998, as well as 5.2-14.5 {mu}m low-resolution spectra obtained with the Infrared Spectrograph instrument on board the Spitzer Space Telescope between 2004 and 2007. The observations were retrieved from the ISO and Spitzer archives and were post-processed interactively by our own routines. For those 47 objects where multi-epoch spectra were available, we analyze mid-infrared spectral variability on annual and/or decadal timescales. We identify 37 variable candidate sources. Many stars show wavelength-independent flux changes, possibly due to variable accretion rates. In several systems, all exhibiting 10 {mu}m silicate emission, the variability of the 6-8 {mu}m continuum, and the silicate feature exhibit different amplitudes. A possible explanation is variable shadowing of the silicate-emitting region by an inner disk structure of changing height or extra silicate emission from dust clouds in the disk atmosphere. Our results suggest that mid-infrared variability, in particular, the wavelength-dependent changes, is more ubiquitous than was known before. Interpreting this variability is a new possibility for exploring the structure of the disk and its dynamical processes.

  18. Cygnids and Taurids - Two classes of infrared objects.

    NASA Technical Reports Server (NTRS)

    Strecker, D. W.; Ney, E. P.; Murdock, T. L.

    1973-01-01

    In a study of the anonymous objects from the IRC Survey, we have found that about 10 percent have large long wave excesses. These infrared stars seem to belong to two classes, one group like NML Cygni (Cygnids) and the other like NML Tauri (Taurids).

  19. Dual-band infrared capabilities for imaging buried object sites

    SciTech Connect

    Del Grande, N.K.; Durbin, P.F.; Gorvad, M.R.; Perkins, D.E.; Clark, G.A.; Hernandez, J.E.; Sherwood, R.J.

    1993-04-02

    We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness variations; weather conditions and measurement times. We use good instrumentation to measure the time-varying temperature differences between buried object sites and undisturbed soil sites. We compare near surface soil temperature differences with radiometric infrared (IR) surface temperature differences recorded at 4.7 {plus_minus} 0.4 {mu}m and at 10.6 {plus_minus} 1.0 {mu}m. By producing selective DBIR image ratio maps, we distinguish temperature-difference patterns from surface emissivity effects. We discuss temperature differences between buried object sites, filled hole site (without buried objects), cleared (undisturbed) soil sites, and grass-covered sites (with and without different types of surface clutter). We compare temperature, emissivity-ratio, visible and near-IR reflectance signatures of surface objects, leafy plants and sod. We discuss the physical aspects of environmental, surface and buried target features affecting interpretation of buried targets, surface objects and natural backgrounds.

  20. Galaxy evolution and large-scale structure in the far-infrared. II - The IRAS faint source survey

    NASA Technical Reports Server (NTRS)

    Lonsdale, Carol J.; Hacking, Perry B.; Conrow, T. P.; Rowan-Robinson, M.

    1990-01-01

    The new IRAS Faint Source Survey data base is used to confirm the conclusion of Hacking et al. (1987) that the 60 micron source counts fainter than about 0.5 Jy lie in excess of predictions based on nonevolving model populations. The existence of an anisotropy between the northern and southern Galactic caps discovered by Rowan-Robinson et al. (1986) and Needham and Rowan-Robinson (1988) is confirmed, and it is found to extend below their sensitivity limit to about 0.3 Jy in 60 micron flux density. The count anisotropy at f(60) greater than 0.3 can be interpreted reasonably as due to the Local Supercluster; however, no one structure accounting for the fainter anisotropy can be easily identified in either optical or far-IR two-dimensional sky distributions. The far-IR galaxy sky distributions are considerably smoother than distributions from the published optical galaxy catalogs. It is likely that structure of the large size discussed here have been discriminated against in earlier studies due to insufficient volume sampling.

  1. Galaxy evolution and large-scale structure in the far-infrared. II - The IRAS faint source survey

    NASA Astrophysics Data System (ADS)

    Lonsdale, Carol J.; Hacking, Perry B.; Conrow, T. P.; Rowan-Robinson, M.

    1990-07-01

    The new IRAS Faint Source Survey data base is used to confirm the conclusion of Hacking et al. (1987) that the 60 micron source counts fainter than about 0.5 Jy lie in excess of predictions based on nonevolving model populations. The existence of an anisotropy between the northern and southern Galactic caps discovered by Rowan-Robinson et al. (1986) and Needham and Rowan-Robinson (1988) is confirmed, and it is found to extend below their sensitivity limit to about 0.3 Jy in 60 micron flux density. The count anisotropy at f(60) greater than 0.3 can be interpreted reasonably as due to the Local Supercluster; however, no one structure accounting for the fainter anisotropy can be easily identified in either optical or far-IR two-dimensional sky distributions. The far-IR galaxy sky distributions are considerably smoother than distributions from the published optical galaxy catalogs. It is likely that structure of the large size discussed here have been discriminated against in earlier studies due to insufficient volume sampling.

  2. Galaxy evolution and large-scale structure in the far-infrared. II. The IRAS faint source survey

    SciTech Connect

    Lonsdale, C.J.; Hacking, P.B.; Conrow, T.P.; Rowan-Robinson, M. Queen Mary College, London )

    1990-07-01

    The new IRAS Faint Source Survey data base is used to confirm the conclusion of Hacking et al. (1987) that the 60 micron source counts fainter than about 0.5 Jy lie in excess of predictions based on nonevolving model populations. The existence of an anisotropy between the northern and southern Galactic caps discovered by Rowan-Robinson et al. (1986) and Needham and Rowan-Robinson (1988) is confirmed, and it is found to extend below their sensitivity limit to about 0.3 Jy in 60 micron flux density. The count anisotropy at f(60) greater than 0.3 can be interpreted reasonably as due to the Local Supercluster; however, no one structure accounting for the fainter anisotropy can be easily identified in either optical or far-IR two-dimensional sky distributions. The far-IR galaxy sky distributions are considerably smoother than distributions from the published optical galaxy catalogs. It is likely that structure of the large size discussed here have been discriminated against in earlier studies due to insufficient volume sampling. 105 refs.

  3. HerMES: Current Cosmic Infrared Background Estimates Can Be Explained by Known Galaxies and Their Faint Companions at z < 4

    NASA Astrophysics Data System (ADS)

    Viero, M. P.; Moncelsi, L.; Quadri, R. F.; Béthermin, M.; Bock, J.; Burgarella, D.; Chapman, S. C.; Clements, D. L.; Conley, A.; Conversi, L.; Duivenvoorden, S.; Dunlop, J. S.; Farrah, D.; Franceschini, A.; Halpern, M.; Ivison, R. J.; Lagache, G.; Magdis, G.; Marchetti, L.; Álvarez-Márquez, J.; Marsden, G.; Oliver, S. J.; Page, M. J.; Pérez-Fournon, I.; Schulz, B.; Scott, Douglas; Valtchanov, I.; Vieira, J. D.; Wang, L.; Wardlow, J.; Zemcov, M.

    2015-08-01

    We report contributions to cosmic infrared background (CIB) intensities originating from known galaxies and their faint companions at submillimeter wavelengths. Using the publicly available UltraVISTA catalog and maps at 250, 350, and 500 μm from the Herschel Multi-tiered Extragalactic Survey, we perform a novel measurement that exploits the fact that uncataloged sources may bias stacked flux densities—particularly if the resolution of the image is poor—and intentionally smooth the images before stacking and summing intensities. By smoothing the maps we are capturing the contribution of faint (undetected in {K}S˜ 23.4) sources that are physically associated, or correlated, with the detected sources. We find that the cumulative CIB increases with increased smoothing, reaching 9.82 ± 0.78, 5.77 ± 0.43 and 2.32+/- 0.19 {{nWm}}-2 {{sr}}-1 at 250, 350, and 500 μm at 300 {arcsec} FWHM. This corresponds to a fraction of the fiducial CIB of 0.94 ± 0.23, 1.07 ± 0.31, and 0.97 ± 0.26 at 250, 350, and 500 μm, where the uncertainties are dominated by those of the absolute CIB. We then propose, with a simple model combining parametric descriptions for stacked flux densities and stellar mass functions, that emission from galaxies with log(M/{M}⊙ )\\gt 8.5 can account for most of the measured total intensities and argue against contributions from extended, diffuse emission. Finally, we discuss prospects for future survey instruments to improve the estimates of the absolute CIB levels, and observe any potentially remaining emission at z\\gt 4.

  4. GTC/OSIRIS SPECTROSCOPIC IDENTIFICATION OF A FAINT L SUBDWARF IN THE UKIRT INFRARED DEEP SKY SURVEY

    SciTech Connect

    Lodieu, N.

    2010-01-10

    We present the discovery of an L subdwarf in 234 deg{sup 2} common to the UK InfraRed Telescope (UKIRT) Infrared Deep Sky Survey Large Area Survey Data Release 2 and the Sloan Digital Sky Survey Data Release 3. This is the fifth L subdwarf announced to date, the first one identified in the UKIRT Infrared Deep Sky Survey, and the faintest known. The blue optical and near-infrared colors of ULAS J135058.86+081506.8 and its overall spectra energy distribution are similar to the known mid-L subdwarfs. Low-resolution optical (700-1000 nm) spectroscopy with the Optical System for Imaging and low Resolution Integrated Spectroscopy spectrograph on the 10.4 m Gran Telescopio de Canarias reveals that ULAS J135058.86+081506.8 exhibits a strong K I pressure-broadened line at 770 nm and a red slope longward of 800 nm, features characteristics of L-type dwarfs. From direct comparison with the four known L subdwarfs, we estimate its spectral type to be sdL4-sdL6 and derive a distance in the interval 94-170 pc. We provide a rough estimate of the space density for mid-L subdwarfs of 1.5 x 10{sup -4} pc{sup -3}.

  5. INFRARED SPECTRAL OBSERVATION OF EIGHT BL LAC OBJECTS FROM THE SPITZER INFRARED SPECTROGRAPH

    SciTech Connect

    Chen, P. S.; Shan, H. G.

    2011-05-01

    The Spitzer Infrared Spectrograph (IRS) low-resolution spectra for eight BL Lac objects are presented in this paper. It can be seen that the infrared spectrum of S5 0716+714 shows in the IRS region many emission features that would be from a nearby galaxy. It is also shown that, except for the silicate absorptions around 10 {mu}m for some sources, emission lines in the infrared spectra for the other seven BL Lac objects are indeed very weak or absent. In addition, ignoring the silicate feature, all spectra can be well fitted by a power-law distribution indicative of the emission mechanism of the synchrotron radiation for these BL Lac objects in the IRS region.

  6. The AKARI Far-Infrared Surveyor young stellar object catalog

    NASA Astrophysics Data System (ADS)

    Tóth, L. Viktor; Marton, Gábor; Zahorecz, Sarolta; Balázs, Lajos G.; Ueno, Munetaka; Tamura, Motohide; Kawamura, Akiko; Kiss, Zoltán T.; Kitamura, Yoshimi

    2014-02-01

    We demonstrate the use of the AKARI all-sky survey photometric data in the study of galactic star formation. Our aim was to select young stellar objects (YSOs) in the AKARI Far-Infrared Surveyor (FIS) Bright Source Catalogue. We used AKARI/FIS and Wide-field Infrared Survey Explorer (WISE) data to derive mid- and far-infrared colors of YSOs. Classification schemes based on quadratic discriminant analysis (QDA) have been given for YSOs and the training catalog for QDA was the whole-sky selection of previously known YSOs (i.e., listed in the SIMBAD database). A new catalog of AKARI FIS YSO candidates including 44001 sources has been prepared; the reliability of the classification is over 90%, as tested in comparison to known YSOs. As much as 76% of our YSO candidates are from previously uncatalogued types. The vast majority of these sources are Class I and II types according to the Lada classification. The distribution of AKARI FIS YSOs is well correlated with that of the galactic ISM; local over-densities were found on infrared loops and towards the cold clumps detected by Planck.

  7. Preliminary analysis of an ultraviolet Hubble Space Telescope faint object camera image of the center of M31

    NASA Technical Reports Server (NTRS)

    King, I. R.; Deharveng, J. M.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Crane, P.; Disney, M. J.; Jakobsen, P.; Kamperman, T. M.

    1992-01-01

    A 5161 s exposure was taken with the FOC on the central 44 arcsec of M31, through a filter centered at 1750 A. Much of the light is redleak from visible wavelengths, but nearly half of it is genuine UV. The image shows the same central peak found earlier by Stratoscope, with a somewhat steeper dropoff outside that peak. More than 100 individual objects are seen, some pointlike and some slightly extended. We identify them as post-asymptotic giant branch stars, some of them surrounded by a contribution from their accompanying planetary nebulae. These objects contribute almost a fifth of the total UV light, but fall far short of accounting for all of it. We suggest that the remainder may result from the corresponding evolutionary tracks in a population more metal-rich than solar.

  8. INFRARED SPECTROSCOPY OF INTERMEDIATE-MASS YOUNG STELLAR OBJECTS

    SciTech Connect

    Pitann, Jan; Bouwman, Jeroen; Krause, Oliver; Henning, Thomas; Hennemann, Martin

    2011-12-10

    In this paper, we present Spitzer Infrared Spectrograph spectroscopy for 14 intermediate-mass young stellar objects (YSOs). We use Spitzer spectroscopy to investigate the physical properties of these sources and their environments. Our sample can be divided into two types of objects: young isolated, embedded objects with spectra that are dominated by ice and silicate absorption bands, and more evolved objects that are dominated by extended emission from polycyclic aromatic hydrocarbons (PAHs) and pure H{sub 2} rotational lines. We are able to constrain the illuminating FUV fields by classifying the PAH bands below 9 {mu}m. For most of the sources we are able to detect several atomic fine structure lines. In particular, the [Ne II] line appearing in two regions could originate from unresolved photodissociation regions or J-shocks. We relate the identified spectral features to observations obtained from NIR through submillimeter imaging. The spatial extent of several H{sub 2} and PAH bands is matched with morphologies identified in previous Infrared Array Camera observations. This also allows us to distinguish between the different H{sub 2} excitation mechanisms. In addition, we calculate the optical extinction from the silicate bands and use this to constrain the spectral energy distribution fit, allowing us to estimate the masses of these YSOs.

  9. Nonuniform Dust Outflow Observed around Infrared Object NML Cygni

    NASA Astrophysics Data System (ADS)

    Monnier, J. D.; Bester, M.; Danchi, W. C.; Johnson, M. A.; Lipman, E. A.; Townes, C. H.; Tuthill, P. G.; Geballe, T. R.; Nishimoto, D.; Kervin, P. W.

    1997-05-01

    Measurements by the University of California Berkeley Infrared Spatial Interferometer at 11.15 μm have yielded strong evidence for multiple dust shells and/or significant asymmetric dust emission around NML Cyg. New observations reported also include multiple 8-13 μm spectra taken from 1994-1995 and N-band (10.2 μm) photometry from 1980-1992. These and past measurements are analyzed and fitted to a model of the dust distribution around NML Cyg. No spherically symmetric single dust shell model is found consistent with both near- and mid-infrared observations. However, a circularly symmetric maximum entropy reconstruction of the 11 μm brightness distribution suggests a double-shell model for the dust distribution. Such a model, consisting of a geometrically thin shell of intermediate optical depth (τ11 μm ~ 1.9) plus an outer shell (τ11 μm ~ 0.33), is consistent not only with the 11 μm visibility data but also with near-infrared speckle measurements, the broadband spectrum, and the 9.7 μm silicate feature. The outer shell, or large-scale structure, is revealed only by long-baseline interferometry at 11 μm, being too cold (~400 K) to contribute in the near-infrared and having no unambiguous spectral signature in the mid-infrared. The optical constants of Ossenkopf, Henning, & Mathis proved superior to the Draine & Lee (1984) constants in fitting the detailed shape of the silicate feature and broadband spectrum for this object. Recent observations of H2O maser emission around NML Cyg by Richards, Yates, & Cohen (1996) are consistent with the location of the two dust shells and provide further evidence for the two-shell model.

  10. Fast calculation of object infrared spectral scattering based on CUDA

    NASA Astrophysics Data System (ADS)

    Li, Liang-chao; Niu, Wu-bin; Wu, Zhen-sen

    2010-11-01

    Computational unified device architecture (CUDA) is used for paralleling the spectral scattering calculation from non-Lambertian object of sky and earth background irradiation. The bidirectional reflectance distribution function (BRDF) of five parameter model is utilized in object surface element scattering calculation. The calculation process is partitioned into many threads running in GPU kernel and each thread computes a visible surface element infrared spectral scattering intensity in a specific incident direction, all visible surface elements' intensity are weighted and averaged to obtain the object surface scattering intensity. The comparison of results of the CPU calculation and CUDA parallel calculation of a cylinder shows that the CUDA parallel calculation speed improves more than two hundred times in meeting the accuracy, with a high engineering value.

  11. A study of ultraviolet absorption lines through the complete Galactic halo by the analysis of HST faint object spectrograph spectra of active Galactic nuclei, 1

    NASA Technical Reports Server (NTRS)

    Burks, Geoffrey S.; Bartko, Frank; Shull, J. Michael; Stocke, John T.; Sachs, Elise R.; Burbidge, E. Margaret; Cohen, Ross D.; Junkkarinen, Vesa T.; Harms, Richard J.; Massa, Derck

    1994-01-01

    The ultraviolet (1150 - 2850 A) spectra of a number of active galactic nuclei (AGNs) observed with the Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) have been used to study the properties of the Galactic halo. The objects that served as probes are 3C 273, PKS 0454-220, Pg 1211+143, CSO 251, Ton 951, and PG 1351+640. The equivalent widths of certain interstellar ions have been measured, with special attention paid to the C IV/C II and Si IV/Si II ratios. These ratios have been intercompared, and the highest values are found in the direction of 3C 273, where C IV/C II = 1.2 and Si IV/Si II greater than 1. These high ratios may be due to a nearby supernova remnant, rather than to ionized gas higher up in the Galactic halo. Our data give some support to the notion that QSO metal-line systems may arise from intervening galaxies which contain high supernova rates, galactic fountains, and turbulent mixing layers.

  12. Discovery of Associated Absorption Lines in an X-Ray Warm Absorber: Hubble Space Telescope Faint Object Spectrograph Observations of MR 2251-178

    NASA Technical Reports Server (NTRS)

    Monier, Eric M.; Mathur, Smita; Wilkes, Belinda; Elvis, Martin

    2001-01-01

    The presence of a 'warm absorber' was first suggested to explain spectral variability in an X-ray spectrum of the radio-quiet quasi-stellar object (QSO) MR 2251-178. A unified picture, in which X-ray warm absorbers and 'intrinsic' UV absorbers are the same, offers the opportunity to probe the nuclear environment of active galactic nuclei. To test this scenario and understand the physical properties of the absorber, we obtained a UV spectrum of MR 2251-178 with the Faint Object Spectrograph on board the Hubble Space Telescope (HST). The HST spectrum clearly shows absorption due to Lyalpha, N v, and C IV, blueshifted by 300 km s(exp -1) from the emission redshift of the QSO. The rarity of both X-ray and UV absorbers in radio-quiet QSOs suggests these absorbers are physically related, if not identical. Assuming the unified scenario, we place constraints on the physical parameters of the absorber and conclude the mass outflow rate is essentially the same as the accretion rate in MR 2251-178.

  13. Characteristics analysis of infrared polarization for several typical artificial objects

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Han, Jian-tao; Li, Jicheng; Yang, Wei-ping; Gong, Ting

    2014-10-01

    It is a difficult point to detect and recognize artificial targets under the disturbance of the complex ground clutter when remote sensing and detection to the earth. Using the different polarization information between artificial object and natural scenery, the ability to distinguish artificial targets from natural scenery can be promoted effectively. On account that the differences of polarization characteristics is an important factor in designing the target recognition method, this paper focuses attention on the application of remote sensing and reconnaissance and makes detailed research on the long wave infrared polarization characteristics of several typical metallic targets, such as aluminum plate and iron plate and the aluminum plate that be coated with black paint or yellow green camouflage. Then, the changing rules of the degree and angle of the long wave infrared polarization changing with the measurement temperature are analyzed and researched. Work of this paper lays the theoretical foundation for the design of remote sensing and detection system based on the infrared polarization information in the future.

  14. Design of adaptive objective lens for ultrabroad near infrared imaging

    NASA Astrophysics Data System (ADS)

    Lan, Gongpu; Li, Guoqiang

    2016-03-01

    We present a compound adaptive objective lens in which a water-filled membrane lens is inserted into a front group (one lens) and a back group (two lenses). This adaptive objective lens works in the ultrabroad near infrared waveband (760nm ~ 920nm) with the volume scan of > 1mm3 and the resolution of 2.8 μm (calculated at the wavelength of 840 nm). The focal range is 19.5mm ~ 20.5mm and the numerical number is 0.196. The size of the adaptive lens is 10mm (diameter) × 17mm (length). This kind of lens can be widely used in three-dimensional (3D) volume biomedical imaging instruments, such as confocal microscope, optical coherence tomography (OCT), two photon microscope, etc.

  15. Rapid response near-infrared spectrophotometric characterization of Near Earth Objects

    NASA Astrophysics Data System (ADS)

    Mommert, Michael; Trilling, David; Axelrod, Tim; Butler, Nat; Jedicke, Robert; Moskovitz, Nicholas; Pichardo, Barbara; Reyes, Mauricio

    2014-11-01

    Small NEOs are, as a whole, poorly characterized, and we know nothing about the physical properties of the majority of all NEOs. The rate of NEO discoveries is increasing each year, and projects to determine the physical properties of NEOs are lagging behind. NEOs are faint, and generally even fainter by the time that follow-up characterizations can be made days or weeks later. There is a need for a high-throughput, high-efficiency physical characterization strategy in which hundreds of faint NEOs can be characterized each year. Broadband photometry in the near-infrared is sufficiently diagnostic to assign taxonomic types, and hence constrain both the individual and ensemble properties of NEOs. We will present results from our recently initiated program of rapid response near-infrared spectrophotometric characterization of NEOs. We are using UKIRT (on Mauna Kea) and the RATIR instrument on the 1.5m telescope at the San Pedro Martir Observatory (Mexico) to allow us to make observations most nights of the year in robotic/queue mode. This technique is powerful and fast. We have written automated software that allows us to observe NEOs very soon after discovery. Our targets are NEOs that are generally too faint for other characterization techniques. We are on pace to characterize hundreds of NEOs per year.

  16. A Hubble Space Telescope Faint Object Spectrograph Survey for Broad Absorption Lines in a Sample of Low-redshift Weak [O III] Quasi-stellar Objects

    NASA Astrophysics Data System (ADS)

    Turnshek, David A.; Monier, Eric M.; Sirola, Christopher J.; Espey, Brian R.

    1997-02-01

    The study by Boroson & Meyers led to the suggestion that radio-quiet QSOs with weak [O III] and strong Fe II emission spectra form a class of QSOs that has a high probability of exhibiting broad absorption lines (BALs) in their spectra. Furthermore, they argued that since narrow-line [O III] emission is almost certainly emitted isotropically, this indicates that such objects have relatively large BAL region covering factors. Low covering factor models are consistent with scenarios in which most QSOs have BAL regions, while higher covering factor models are consistent with scenarios in which there are special classes of QSOs with large BAL region outflows. By making Hubble Space Telescope (HST) FOS observations and using IUE or HST archival data when available, the details of the Boroson & Meyers suggestion have been explored by directly searching for classical C IV BALs in a sample of 18 QSOs with weak [O III] and often strong Fe II emission. Six of the 18 QSOs are found to exhibit C IV BALs. (In the archival sample, four of six objects have BALs, while two of the 12 new objects observed with the HST FOS have BALs.) However, there is evidence that the sample is heterogeneous, with IRAS-selected objects and high-luminosity objects having a greater tendency to exhibit BALs. If an isotropic model for [O III] emission equivalent width is considered, the results suggest that for the 18 object sample as a whole the average BAL region covering factor is ~0.33+0.20-0.09, which is significantly larger (with a more than 99% probability) than the overall fraction of QSOs observed to have BALs (normally taken as ~0.1). Given possible selection effects, in the context of an isotropic model the results may indicate that some of the sample objects have covering factors <<0.33, while others have covering factors >>0.33. At the same time, it is impossible to rule out in a non-model-dependent way a scenario in which orientation effects are important and covering factors are

  17. Optical-faint, Far-infrared-bright Herschel Sources in the CANDELS Fields: Ultra-luminous Infrared Galaxies at z > 1 and the Effect of Source Blending

    NASA Astrophysics Data System (ADS)

    Yan, Haojing; Stefanon, Mauro; Ma, Zhiyuan; Willner, S. P.; Somerville, Rachel; Ashby, Matthew L. N.; Davé, Romeel; Pérez-González, Pablo G.; Cava, Antonio; Wiklind, Tommy; Kocevski, Dale; Rafelski, Marc; Kartaltepe, Jeyhan; Cooray, Asantha; Koekemoer, Anton M.; Grogin, Norman A.

    2014-07-01

    The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven "SDSS-invisible," very bright 250 μm sources (S 250 > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using the near-IR or the optical images directly for position priors. This is an improvement over the previous decomposition efforts where the priors are from mid-IR data that still suffer from the problem of source blending. We found that in most cases the single Herschel sources are made of multiple components that are not necessarily at the same redshifts. Our decomposition succeeded in identifying and extracting their major contributors. We show that these are all ultra-luminous infrared galaxies at z ~ 1-2 whose high L IR is mainly due to dust-obscured star formation. Most of them would not be selected as submillimeter galaxies. They all have complicated morphologies indicative of mergers or violent instability, and their stellar populations are heterogeneous in terms of stellar masses, ages, and formation histories. Their current ultra-luminous infrared galaxy phases are of various degrees of importance in their stellar mass assembly. Our practice provides a promising starting point for developing an automatic routine to reliably study bright Herschel sources.

  18. OPTICAL-FAINT, FAR-INFRARED-BRIGHT HERSCHEL SOURCES IN THE CANDELS FIELDS: ULTRA-LUMINOUS INFRARED GALAXIES AT z > 1 AND THE EFFECT OF SOURCE BLENDING

    SciTech Connect

    Yan, Haojing; Stefanon, Mauro; Ma, Zhiyuan; Willner, S. P.; Ashby, Matthew L. N.; Somerville, Rachel; Davé, Romeel; Pérez-González, Pablo G.; Cava, Antonio; Wiklind, Tommy; Kocevski, Dale; Rafelski, Marc; Kartaltepe, Jeyhan; Cooray, Asantha; Koekemoer, Anton M.; Grogin, Norman A.

    2014-07-01

    The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven ''SDSS-invisible'', very bright 250 μm sources (S {sub 250} > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using the near-IR or the optical images directly for position priors. This is an improvement over the previous decomposition efforts where the priors are from mid-IR data that still suffer from the problem of source blending. We found that in most cases the single Herschel sources are made of multiple components that are not necessarily at the same redshifts. Our decomposition succeeded in identifying and extracting their major contributors. We show that these are all ultra-luminous infrared galaxies at z ∼ 1-2 whose high L {sub IR} is mainly due to dust-obscured star formation. Most of them would not be selected as submillimeter galaxies. They all have complicated morphologies indicative of mergers or violent instability, and their stellar populations are heterogeneous in terms of stellar masses, ages, and formation histories. Their current ultra-luminous infrared galaxy phases are of various degrees of importance in their stellar mass assembly. Our practice provides a promising starting point for developing an automatic routine to reliably study bright Herschel sources.

  19. The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts for 0.2-2 μm Wavelength

    NASA Astrophysics Data System (ADS)

    Windhorst, Rogier A.; Cohen, Seth H.; Hathi, Nimish P.; McCarthy, Patrick J.; Ryan, Russell E., Jr.; Yan, Haojing; Baldry, Ivan K.; Driver, Simon P.; Frogel, Jay A.; Hill, David T.; Kelvin, Lee S.; Koekemoer, Anton M.; Mechtley, Matt; O'Connell, Robert W.; Robotham, Aaron S. G.; Rutkowski, Michael J.; Seibert, Mark; Straughn, Amber N.; Tuffs, Richard J.; Balick, Bruce; Bond, Howard E.; Bushouse, Howard; Calzetti, Daniela; Crockett, Mark; Disney, Michael J.; Dopita, Michael A.; Hall, Donald N. B.; Holtzman, Jon A.; Kaviraj, Sugata; Kimble, Randy A.; MacKenty, John W.; Mutchler, Max; Paresce, Francesco; Saha, Abihit; Silk, Joseph I.; Trauger, John T.; Walker, Alistair R.; Whitmore, Bradley C.; Young, Erick T.

    2011-04-01

    We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the Great Observatories Origins Deep Survey (GOODS) South field. The new WFC3 ERS data provide calibrated, drizzled mosaics in the UV filters F225W, F275W, and F336W, as well as in the near-IR filters F098M (Ys ), F125W (J), and F160W (H) with 1-2 HST orbits per filter. Together with the existing HST Advanced Camera for Surveys (ACS) GOODS-South mosaics in the BViz filters, these panchromatic 10-band ERS data cover 40-50 arcmin2 at 0.2-1.7 μm in wavelength at 0farcs07-0farcs15 FWHM resolution and 0farcs090 Multidrizzled pixels to depths of AB sime 26.0-27.0 mag (5σ) for point sources, and AB sime 25.5-26.5 mag for compact galaxies. In this paper, we describe (1) the scientific rationale, and the data taking plus reduction procedures of the panchromatic 10-band ERS mosaics, (2) the procedure of generating object catalogs across the 10 different ERS filters, and the specific star-galaxy separation techniques used, and (3) the reliability and completeness of the object catalogs from the WFC3 ERS mosaics. The excellent 0farcs07-0farcs15 FWHM resolution of HST/WFC3 and ACS makes star-galaxy separation straightforward over a factor of 10 in wavelength to AB sime 25-26 mag from the UV to the near-IR, respectively. Our main results are: (1) proper motion of faint ERS stars is detected over 6 years at 3.06 ± 0.66 mas year-1 (4.6σ), consistent with Galactic structure models; (2) both the Galactic star counts and the galaxy counts show mild but significant trends of decreasing count slopes from the mid-UV to the near-IR over a factor of 10 in wavelength; (3) combining the 10-band ERS counts with the panchromatic Galaxy and Mass Assembly survey counts at the bright end (10 mag <~ AB lsim 20 mag) and the Hubble Ultra Deep Field counts in the BVizYsJH filters at the faint end (24 mag <~ AB lsim 30 mag) yields galaxy counts that are well measured over the entire

  20. A 21 Centimeter Absorber Identified with a Spiral Galaxy: Hubble Space Telescope Faint Object Spectrograph and Wide-Field Camera Observations of 3CR 196

    NASA Technical Reports Server (NTRS)

    Cohen, Ross D.; Beaver, E. A.; Diplas, Athanassios; Junkkarinen, Vesa T.; Barlow, Thomas A.; Lyons, Ronald W.

    1996-01-01

    We present imaging and spectroscopy of the quasar 3CR 196 (z(sub e) = 0.871), which has 21 cm and optical absorption at z(sub a) = 0.437. We observed the region of Ly alpha absorption in 3CR 196 at z(sub a) = 0.437 with the Faint Object Spectrograph on the Hubble Space Telescope. This region of the spectrum is complicated because of the presence of a Lyman limit and strong lines from a z(sub a) approx. z(sub e) system. We conclude that there is Ly alpha absorption with an H I column density greater than 2.7 x 10(exp 19) cm(exp -2) and most probably 1.5 x 10(exp 20) cm(exp -2). Based on the existence of the high H I column density along both the optical and radio lines of sight, separated by more than 15 kpc, we conclude that the Ly alpha absorption must arise in a system comparable in size to the gaseous disks of spiral galaxies. A barred spiral galaxy, previously reported as a diffuse object in the recent work of Boisse and Boulade, can be seen near the quasar in an image taken at 0.1 resolution with the Wide Field Planetary Camera 2 on the HST. If this galaxy is at the absorption redshift, the luminosity is approximately L(sub *) and any H I disk should extend in front of the optical quasar and radio lobes of 3CR 196, giving rise to both the Ly alpha and 21 cm absorption. In the z(sub a) approx. z(sub e) system we detect Lyman lines and the Lyman limit, as well as high ion absorption lines of C III, N V, S VI, and O VI. This absorption probably only partially covers the emission-line region. The ionization parameter is approximately 0.1. Conditions in this region may be similar to those in broad absorption line QSOs.

  1. Robust visual tracking of infrared object via sparse representation model

    NASA Astrophysics Data System (ADS)

    Ma, Junkai; Liu, Haibo; Chang, Zheng; Hui, Bin

    2014-11-01

    In this paper, we propose a robust tracking method for infrared object. We introduce the appearance model and the sparse representation in the framework of particle filter to achieve this goal. Representing every candidate image patch as a linear combination of bases in the subspace which is spanned by the target templates is the mechanism behind this method. The natural property, that if the candidate image patch is the target so the coefficient vector must be sparse, can ensure our algorithm successfully. Firstly, the target must be indicated manually in the first frame of the video, then construct the dictionary using the appearance model of the target templates. Secondly, the candidate image patches are selected in following frames and the sparse coefficient vectors of them are calculated via l1-norm minimization algorithm. According to the sparse coefficient vectors the right candidates is determined as the target. Finally, the target templates update dynamically to cope with appearance change in the tracking process. This paper also addresses the problem of scale changing and the rotation of the target occurring in tracking. Theoretic analysis and experimental results show that the proposed algorithm is effective and robust.

  2. Object tracking in a stereo and infrared vision system

    NASA Astrophysics Data System (ADS)

    Colantonio, S.; Benvenuti, M.; Di Bono, M. G.; Pieri, G.; Salvetti, O.

    2007-01-01

    In this paper, we deal with the problem of real-time detection, recognition and tracking of moving objects in open and unknown environments using an infrared (IR) and visible vision system. A thermo-camera and two stereo visible-cameras synchronized are used to acquire multi-source information: three-dimensional data about target geometry and its thermal information are combined to improve the robustness of the tracking procedure. Firstly, target detection is performed by extracting its characteristic features from the images and then by storing the computed parameters on a specific database; secondly, the tracking task is carried on using two different computational approaches. A Hierarchical Artificial Neural Network (HANN) is used during active tracking for the recognition of the actual target, while, when partial occlusions or masking occur, a database retrieval method is used to support the search of the correct target followed. A prototype has been tested on case studies regarding the identification and tracking of animals moving at night in an open environment, and the surveillance of known scenes for unauthorized access control.

  3. MOIRCS: multi-object infrared camera and spectrograph for SUBARU

    NASA Astrophysics Data System (ADS)

    Ichikawa, Takashi; Suzuki, Ryuji; Tokoku, Chihiro; Uchimoto, Yuka Katsuno; Konishi, Masahiro; Yoshikawa, Tomohiro; Yamada, Toru; Tanaka, Ichi; Omata, Koji; Nishimura, Tetsuo

    2006-06-01

    MOIRCS is a new Cassegrain instrument of Subaru telescope, dedicated for wide field imaging and multi-object spectroscopy in near-infrared. MOIRCS has been constructed jointly by Tohoku University and the Subaru Telescope and saw the first light in Sept., 2004. The commissioning observations to study both imaging and spectroscopic performance were conducted for about one year. MOIRCS mounts two 2048 × 2048 HAWAII2 arrays and provides a field of view of 4' x 7' with a pixel scale of 0."117. All-lens optical design is optimized for 0.8 to 2.5 μm with no practical chromatic aberration. Observations confirm the high image quality over the field of view without any perceptible degradation even at the field edge. The best seeing we have obtained so far is FWHM=0."18. A novel design of MOIRCS enables us to perform multi-object spectroscopy with aluminum slit masks, which are housed in a carrousel dewar and cooled to ~ 110 K. When choosing MOS mode, a manipulator pulls out a slit mask from the carrousel into the MOIRCS main dewar and sets it properly at the Cassegrain focus. The carrousel is shuttered by a gate valve, so that it can be warmed and cooled independently to exchange slit-mask sets during daytime. We have tested various configurations of 30 or more multi-slit positions in various sky fields and found that targets are dropped at the centers of slits or guide holes within a dispersion of about 0.3 pixels (0."03). MOIRCS has been open to common use specifically for imaging observations since Feb. 2006. The MOS function will be available in next August.

  4. Alignment and Performance of the Infrared Multi-Object Spectrometer

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mentzell, J. Eric; Madison, Timothy J.; Hylan, Jason E.; Mink, Ronald G.; Saha, Timo T.; Tveekrem, June L.; Sparr, Leroy M.; Chambers, V. John; Fitzgerald, Danetter; Greenhouse, Matthew A.; MacKenty, John W.

    2004-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator class instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low-to mid-resolving power (R = 300 - 3000). IRMOS produces simultaneous spectra of approximately 100 objects in its 2.8 x 2.0 arc-min field of view (4 m telescope) using a commercial Micro Electro-Mechanical Systems (MEMS) micro-mirror array (MMA) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the MMA field stop, and the spectrograph images the MMA onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and ambient imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve as a qualitative alignment guide, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides a spectral line at 546.1 nanometers, a blackbody source provides a line at 1550 nanometers, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard and instrument level test results validate this prediction. We conclude with an instrument performance prediction for cryogenic operation and first light in late 2003.

  5. Alignment and performance of the Infrared Multi-Object Spectrometer

    NASA Astrophysics Data System (ADS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mentzell, J. E.; Madison, Timothy J.; Hylan, Jason E.; Mink, Ronald G.; Saha, Timo T.; Tveekrem, June L.; Sparr, Leroy M.; Chambers, Victor J.; Fitzgerald, Danette L.; Greenhouse, Matthew A.; MacKenty, John W.

    2003-10-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator class instrument for the Kitt Peak National Observatory 4 and 2.1 m telescopes. IRMOS is a near-IR (0.8 2.5 μm) spectrometer with low- to mid-resolving power (R = 300 3000). IRMOS produces simultaneous spectra of ~100 objects in its 2.8 ´ 2.0 arc-min field of view (4 m telescope) using a commercial Micro Electro-Mechanical Systems (MEMS) micro-mirror array (MMA) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the MMA field stop, and the spectrograph images the MMA onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and ambient imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve as a qualitative alignment guide, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides a spectral line at 546.1 nm, a blackbody source provides a line at 1550 nm, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard and instrument level test results validate this prediction. We conclude with an instrument performance prediction for cryogenic operation and first light in late 2003.

  6. Kinematics of faint white dwarfs.

    PubMed

    Luyten, W J

    1978-10-01

    An analysis has been made for solar motion for 128 very faint white dwarfs of color class b or a. While about 40% of these stars may be high-velocity objects, it seems definitely indicated that the luminosity of all of them is considerably lower than that for the "normal" white dwarf of the same color. PMID:16592566

  7. Cataloged infrared sources in NIPSS data. I - The RSO 1 catalog. [Near Infrared Photographic Sky Survey Red Stellar Objects

    NASA Technical Reports Server (NTRS)

    Horner, V. M.; Craine, E. R.

    1980-01-01

    A small number of selected near-infrared and visual photographic pairs from the Steward Observatory Near Infrared Photographic Sky Survey have been examined for content of stars more red than (V-I) of about 2.5 magnitudes. A simple manual extraction of these objects was carried out as a part of a preliminary evaluation of survey data and techniques for reducing it; the resulting list has been compiled as the first installment of a Catalog of Red Stellar Objects (Craine et al. 1979). Results of a cross correlation of this catalog with the IRC, AFGL, and EIC infrared catalogs are here presented. The results indicate that these photographs may be particularly useful for purposes of optical identification of short-wavelength infrared sources to limits much fainter than represented by presently existing infrared catalogs.

  8. The correction model and error analysis of infrared radiation temperature measurement of semitransparent object

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaolong; Yang, Li

    2015-10-01

    Based on the theory of infrared radiation and of the infrared thermography, the mathematical correction model of the infrared radiation temperature measurement of semitransparent object is developed taking account by the effects of the atmosphere, surroundings, radiation of transmissivity and many other factors. The effects of the emissivity, transmissivity and measurement error are analysed on temperature measurement error of the infrared thermography. The measurement error of semitransparent object are compared with that of opaque object. The countermeasures to reduce the measurement error are also discussed.

  9. An infrared salient object stereo matching algorithm based on epipolar rectification

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Wu, Lei; Han, Jing; Bai, Lian-fa

    2016-02-01

    Due to the higher noise and less details in infrared images, general matching algorithms are prone to obtaining unsatisfying results. Combining the idea of salient object, we propose a novel infrared stereo matching algorithm which applies to unconstrained stereo rigs. Firstly, we present an epipolar rectification method introducing particle swarm optimization and K-nearest neighbor to deal with the problem of epipolar constraint. Then we make use of transition region to extract salient object in the rectified infrared image pairs. Finally, disparity map is generated by matching salient regions. Experiments show that our algorithm deals with the infrared stereo matching of unconstrained stereo rigs with better accuracy and higher speed.

  10. The HST quasar absorption line key project. 4: HST faint-object spectrograph and ground-based observations of the unusual low-redshift broad absorption-line quasi-stellar object PG 0043+039

    NASA Technical Reports Server (NTRS)

    Turnshek, David A.; Espey, Brian R.; Kopko, Michael, Jr.; Rauch, Michael; Weymann, Ray J.; Jannuzi, Buell T.; Boksenberg, Alec; Bergeron, Jacqueline; Hartig, George F.; Sargent, W. L. W.

    1994-01-01

    Hubble Space Telescope Faint Object Spectrograph (HST FOS) observations have shown that the spectrum of the low-redshift (z(sub em) approximately equal to 0.384) QSO PG 0043+039 exhibits weak broad absorption lines (BALs). The BALs were discovered during the course of UV spectrophotometry made for the HST Quasar Absorption Line Key Project. The HST data are analyzed along with ground-based optical and IUE spectrophotometry. The object is found to have a number of atypical properties relative to normal non-BAL QSOs. The observed continuum is atypical in the sense that it is much weaker than that of a normal optically selected QSO at rest wavelengths approximately less than 2200 A. Intrinsic reddening of E(B-V) approximately equal to 0.11 mag by dust similar to that found in the SMC at the redshift of PG 0043+039 conservatively accounts for the observed continuum shape moderately well. These observed characteristics are typical of low-ionization BAL QSOs, but convincing evidence for BALs due to low-ionization transitions of Mg II, Al III, Al II, or C II does not exist. Therefore, this object may be a misaligned BAL QSO having many of the characteristics of low-ionization BAL QSOs with the sight line passing through a putative dusty region, but evidently missing clouds of high enough column density to produce observable low-ionization BALs. If the intrinsic dust-extinction model is correct, the observations suggest that the dust is not confined to the presumably higher density, low-ionization BAL clouds, but that it has drifted to nearby high-ionization BAL regions. We also consider other possible mechanisms for producing the shape of the continuous energy distribution which cannot be ruled out. We compare the Fe II emission in PG 0043+039 with that in another Key Project QSO, NGC 2841-UB 3, which has optical Fe II emission comparable in strength to that in PG 0043+039, but has anomalously weak UV Fe II emission. In addition, from an analysis of UV and optical

  11. Fainting Starting Parenteral Nutrition.

    PubMed

    Pederiva, Federica; Barbi, Egidio; Zennaro, Floriana; Neri, Elena

    2015-09-01

    Complications such as mechanical accidents, infections, and thrombosis are commonly described in the presence of a central venous catheter. We present a case of a boy who had fainting episodes due to dislocation of a central venous catheter. PMID:25853719

  12. Search for high-proper motion objects with infrared excess

    NASA Astrophysics Data System (ADS)

    Teodorani, Massimo

    2014-12-01

    The possibility of interstellar migration has been theorized during the past thirty years in the form of 'Dysonships' that, using non-relativistic propulsion systems, are able to colonize the Galaxy in a relatively short time compared to the age of the Galaxy and consequently penetrate inside our solar system too. Observational evidence of this can be potentially obtained using the present state of the art of telescopes and related sensors, by following aimed searches and an expanded SETI protocol. Some transient and unrepeated radio signals recorded during standard SETI observations might be due to the transit of high-proper motion artificial sources of extraterrestrial origin, which are expected to show a very weak optical emission, a strong infrared excess and occasional high-energy bursts in the X and Gamma-ray wavelength ranges. Such artificial sources might show an interest to Earth by sending probes to visit it: such a possibility can be investigated scientifically as well.

  13. Spectral matching factors between low-light-level and infrared fusion optoelectronic detector and objects

    NASA Astrophysics Data System (ADS)

    Liu, Lei; Fan, Yinghao; Chang, Benkang

    2009-09-01

    According to the response of photoelectric device to a light source, the formula of spectral matching factor of low-lightlevel and infrared fusion optoelectronic detector-object combination is deduced. The spectral matching factors of photo cathode and infrared detector for green vegetation are calculated and compared. Through the analysis of results it shows that spectral matching factor has influence on the performance of low light level and infrared fusion night vision system.

  14. Herbig-Haro Objects and Mid-infrared Outflows in the Vela C Molecular Cloud

    NASA Astrophysics Data System (ADS)

    Zhang, Miaomiao; Wang, Hongchi; Henning, Thomas

    2014-08-01

    We have performed a deep [S II] λλ6717/6731 wide field Herbig-Haro (HH) object survey toward the Vela C molecular cloud with a sky coverage of about 2 deg2. In total, 18 new HH objects, HH 1090-1107, are discovered and the two previously known HH objects, HH 73-74, are also detected in our [S II] images. We also present an investigation of mid-infrared outflows in the Vela C molecular cloud using the Wide-field Infrared Survey Explorer images taken from AllWISE data release. Using the method suggested by Zhang & Wang, 11 extended green objects (EGOs) are identified to be the mid-infrared outflows, including 6 new mid-infrared outflows that have not been detected previously at other wavelengths and 5 mid-infrared counterparts of the HH objects detected in this work. Using the AllWISE Source Catalog and the source classification scheme suggested by Koenig et al., we have identified 56 young stellar object (YSO) candidates in the Vela C molecular cloud. The possible driving sources of the HH objects and EGOs are discussed based on the morphology of HH objects and EGOs and the locations of HH objects, EGOs and YSO candidates. Finally we associate 12 HH objects and 5 EGOs with 10 YSOs and YSO candidates. The median length of the outflows in Vela C is 0.35 pc and the outflows seem to be oriented randomly.

  15. Herbig-haro objects and mid-infrared outflows in the VELA C molecular cloud

    SciTech Connect

    Zhang, Miaomiao; Wang, Hongchi; Henning, Thomas

    2014-08-01

    We have performed a deep [S II] λλ6717/6731 wide field Herbig-Haro (HH) object survey toward the Vela C molecular cloud with a sky coverage of about 2 deg{sup 2}. In total, 18 new HH objects, HH 1090-1107, are discovered and the two previously known HH objects, HH 73-74, are also detected in our [S II] images. We also present an investigation of mid-infrared outflows in the Vela C molecular cloud using the Wide-field Infrared Survey Explorer images taken from AllWISE data release. Using the method suggested by Zhang and Wang, 11 extended green objects (EGOs) are identified to be the mid-infrared outflows, including 6 new mid-infrared outflows that have not been detected previously at other wavelengths and 5 mid-infrared counterparts of the HH objects detected in this work. Using the AllWISE Source Catalog and the source classification scheme suggested by Koenig et al., we have identified 56 young stellar object (YSO) candidates in the Vela C molecular cloud. The possible driving sources of the HH objects and EGOs are discussed based on the morphology of HH objects and EGOs and the locations of HH objects, EGOs and YSO candidates. Finally we associate 12 HH objects and 5 EGOs with 10 YSOs and YSO candidates. The median length of the outflows in Vela C is 0.35 pc and the outflows seem to be oriented randomly.

  16. Infrared detection, recognition and identification of handheld objects

    NASA Astrophysics Data System (ADS)

    Adomeit, Uwe

    2012-10-01

    A main criterion for comparison and selection of thermal imagers for military applications is their nominal range performance. This nominal range performance is calculated for a defined task and standardized target and environmental conditions. The only standardization available to date is STANAG 4347. The target defined there is based on a main battle tank in front view. Because of modified military requirements, this target is no longer up-to-date. Today, different topics of interest are of interest, especially differentiation between friend and foe and identification of humans. There is no direct way to differentiate between friend and foe in asymmetric scenarios, but one clue can be that someone is carrying a weapon. This clue can be transformed in the observer tasks detection: a person is carrying or is not carrying an object, recognition: the object is a long / medium / short range weapon or civil equipment and identification: the object can be named (e. g. AK-47, M-4, G36, RPG7, Axe, Shovel etc.). These tasks can be assessed experimentally and from the results of such an assessment, a standard target for handheld objects may be derived. For a first assessment, a human carrying 13 different handheld objects in front of his chest was recorded at four different ranges with an IR-dual-band camera. From the recorded data, a perception experiment was prepared. It was conducted with 17 observers in a 13-alternative forced choice, unlimited observation time arrangement. The results of the test together with Minimum Temperature Difference Perceived measurements of the camera and temperature difference and critical dimension derived from the recorded imagery allowed defining a first standard target according to the above tasks. This standard target consist of 2.5 / 3.5 / 5 DRI line pairs on target, 0.24 m critical size and 1 K temperature difference. The values are preliminary and have to be refined in the future. Necessary are different aspect angles, different

  17. Design of polarized infrared athermal telephoto objective for penetrating the fog

    NASA Astrophysics Data System (ADS)

    Gao, Duorui; Fu, Qiang; Zhao, Zhao; Zhao, Bin; Zhong, Lijun; Zhan, Juntong

    2014-11-01

    Polarized infrared imaging technology is a new detection technique which own the ability of spying through the fog, highlighting the target and recognizing the forgeries, these characters make it a good advantage of increasing the work distance in the fog. Compared to the traditional infrared imaging method, polarized infrared imaging can identify the background and target easily, that is the most distinguishing feature of polarized infrared imaging technology. Owning to the large refractive index of the infrared material, temperature change will bring defocus seriously, athermal infrared objective is necessarily. On the other hand, athermal objective has large total length, and hard to be integrated for their huge volume. However telephoto objective has the character of small volume and short total length. The paper introduce a method of polarized and athermal infrared telephoto objective which can spy the fog. First assign the optical power of the fore group and the rear group on the basis of the principle of telephoto objective, the power of the fore group is positive and the rear group is negative; then distribute the optical power within each group to realize the ability of athermalization, finally computer-aided software is used to correct aberration. In order to prove the feasibility of the scheme, an athermal optical system was designed by virtue of ZEMAX software which works at 8~12 µm, the focal length of 150mm, F number is 2, and total length of the telephoto objective is 120mm. The environment temperature analysis shows that the optical system have stable imaging quality, MTF is close to diffraction limit. This telephoto objective is available for infrared polarized imaging.

  18. NEAR-INFRARED PROPERTIES OF THE X-RAY-EMITTING YOUNG STELLAR OBJECTS IN THE CARINA NEBULA

    SciTech Connect

    Preibisch, Thomas; Hodgkin, Simon; Irwin, Mike; Lewis, James R.; King, Robert R.; McCaughrean, Mark J.; Zinnecker, Hans; Townsley, Leisa; Broos, Patrick

    2011-05-01

    The Great Nebula in Carina (NGC 3372) is the best target to study in detail the process of violent massive star formation and the resulting feedback effects of cloud dispersal and triggered star formation. While the population of massive stars is rather well studied, the associated low-mass stellar population was largely unknown up to now. The near-infrared study in this paper builds on the results of the Chandra Carina Complex Project, that detected 14,368 X-ray sources in the 1.4 deg{sup 2} survey region, an automatic source classification study that classified 10,714 of these X-ray sources as very likely young stars in Carina, and an analysis of the clustering properties of the X-ray-selected Carina members. In order to determine physical properties of the X-ray-selected stars, most of which were previously unstudied, we used HAWK-I at the ESO Very Large Telescope to conduct a very deep near-IR survey with subarcsecond angular resolution, covering an area of about 1280 arcmin{sup 2}. The HAWK-I images reveal more than 600,000 individual infrared sources, whereby objects as faint as J {approx} 23, H {approx} 22, and K{sub s} {approx} 21 are detected at signal-to-noise ratio (S/N) {>=}3. While less than half of the Chandra X-ray sources have counterparts in the Two Micron All Sky Survey catalog, the {approx}5 mag deeper HAWK-I data reveal infrared counterparts to 6636 (=88.8%) of the 7472 Chandra X-ray sources in the HAWK-I field. We analyze near-infrared color-color and color-magnitude diagrams to derive information about the extinctions, infrared excesses (as tracers for circumstellar disks), ages, and masses of the X-ray-selected objects. The near-infrared properties agree well with the results of the automatic X-ray source classification, showing that the remaining contamination in the X-ray-selected sample of Carina members is very low ({approx}<7%). The shape of the K-band luminosity function of the X-ray-selected Carina members agrees well with that derived

  19. Shape distortions induced by convective effect on hot object in visible, near infrared and infrared bands

    NASA Astrophysics Data System (ADS)

    Delmas, Anthony; Maoult, Yannick Le; Buchlin, Jean-Marie; Sentenac, Thierry; Orteu, Jean-José

    2013-04-01

    The goal of this study is to examine the perturbation induced by the convective effect (or mirage effect) on shape measurement and to give an estimation of the error induced. This work explores the mirage effect in different spectral bands and single wavelengths. A numerical approach is adopted and an original setup has been developed in order to investigate easily all the spectral bands of interest with the help of a CCD camera (Si, 0.35-1.1 μm), a near infrared camera (VisGaAs, 0.8-1.7 μm) or infrared cameras (8-12 μm). Displacements due to the perturbation for each spectral band are measured and finally some hints about how to correct them are given.

  20. First Results from the Faint Infrared Grism Survey (FIGS): First Simultaneous Detection of Lyα Emission and Lyman Break from a Galaxy at z = 7.51

    NASA Astrophysics Data System (ADS)

    Tilvi, V.; Pirzkal, N.; Malhotra, S.; Finkelstein, S. L.; Rhoads, J. E.; Windhorst, R.; Grogin, N. A.; Koekemoer, A.; Zakamska, N. L.; Ryan, R.; Christensen, L.; Hathi, N.; Pharo, J.; Joshi, B.; Yang, H.; Gronwall, C.; Cimatti, A.; Walsh, J.; O’Connell, R.; Straughn, A.; Ostlin, G.; Rothberg, B.; Livermore, R. C.; Hibon, P.; Gardner, Jonathan P.

    2016-08-01

    Galaxies at high redshifts are a valuable tool for studying cosmic dawn, therefore it is crucial to reliably identify these galaxies. Here, we present an unambiguous and first simultaneous detection of both the Lyα emission and the Lyman break from a z=7.512 +/- 0.004 galaxy, observed in the Faint Infrared Grism Survey (FIGS). These spectra, taken with the G102 grism on the Hubble Space Telescope (HST), show a significant emission line detection (6σ ) in two observational position angles (PAs), with Lyα line flux of 1.06+/- 0.19× {10}-17 {erg} {{{s}}}-1 {{cm}}-2. The line flux is nearly a factor of four higher than that in the archival MOSFIRE spectroscopic observations. This is consistent with other recent observations, implying that ground-based near-infrared spectroscopy underestimates the total emission line fluxes, and if confirmed, can have strong implications for reionization studies that are based on ground-based Lyα measurements. A 4σ detection of the NV line in one PA also suggests a weak active galactic nucleus (AGN), and if confirmed, would make this source the highest-redshift AGN yet found. These observations from HST thus clearly demonstrate the sensitivity of the FIGS survey, and the capability of grism spectroscopy for studying the epoch of reionization.

  1. Infrared recombination lines of hydrogen from young objects in the southern Galactic plane

    NASA Technical Reports Server (NTRS)

    Beck, Sara C.; Fischer, Jacqueline; Smith, Howard A.

    1991-01-01

    Near infrared recombination lines of hydrogen are observed in twelve young objects in the southern Galactic plane. The sample includes Herbig-Haro objects and IRAS dark-cloud point sources from the 1987 catalog of Persson and Campbell. In four of the IRAS sources two or three infrared lines are measured, and their intensity ratios are consistent with models of optically thick ionized winds. The intrinsic line shapes, retrieved from maximum-entropy deconvolutions, indicate gas velocities of 100 km/s or more as expected from ionized winds. These sources are apparently embedded pre-main-sequence objects with outflows. They include some of the brightest known YSOs.

  2. Non-destructively reading out information embedded inside real objects by using far-infrared light

    NASA Astrophysics Data System (ADS)

    Okada, Ayumi; Silapasuphakornwong, Piyarat; Suzuki, Masahiro; Torii, Hideyuki; Takashima, Youichi; Uehira, Kazutake

    2015-09-01

    This paper presents a technique that can non-destructively read out information embedded inside real objects by using far-infrared-light. We propose a technique that can protect the copyrights of digital content for homemade products using digital fabrication technologies such as those used in 3D printers. It embeds information on copyrights inside real objects produced by 3D printers by forming fine structures inside the objects as a watermark that cannot be observed from the outside. Fine structures are formed near the surface inside real objects when they are being fabricated. Information embedded inside real objects needs to be read out non-destructively. We used a technique that could non-destructively read out information from inside real objects by using far-infrared light. We conducted experiments where we structured fine cavities inside objects. The disposition of the fine domain contained valuable information. We used the flat and curved surfaces of the objects to identify them. The results obtained from the experiments demonstrated that the disposition patterns of the fine structures appeared on the surface of objects as a temperature profile when far-infrared light was irradiated on their surface. Embedded information could be read out successfully by analyzing the temperature profile images of the surface of the objects that were captured with thermography and these results demonstrated the feasibility of the technique we propose.

  3. Near-Infrared Faint Galaxies in the Subaru Deep Field: Comparing the Theory with Observations for Galaxy Counts, Colors, and Size Distributions to K ~ 24.5

    NASA Astrophysics Data System (ADS)

    Totani, Tomonori; Yoshii, Yuzuru; Maihara, Toshinori; Iwamuro, Fumihide; Motohara, Kentaro

    2001-10-01

    Galaxy counts in the K band, (J-K) colors, and apparent size distributions of faint galaxies in the Subaru Deep Field (SDF) down to K~24.5 were studied in detail. Special attention has been paid to take into account various selection effects, including the cosmological dimming of surface brightness, to avoid any systematic bias that may be the origin of controversy in previously published results. We also tried to be very careful about systematic model uncertainties; we present a comprehensive survey of these systematic uncertainties and dependence on various parameters, and we have shown that the dominant factors to determine galaxy counts in this band are cosmology and number evolution. We found that the pure luminosity evolution (PLE) model is very consistent with all the SDF data down to K~22.5, without any evidence for number or size evolution in a low-density, Λ-dominated flat universe, which is now favored by various cosmological observations. On the other hand, a number evolution of galaxies with η~2, when invoked as the luminosity conserving mergers as φ*~(1+z)η and L*~(1+z)-η for all types of galaxies, is necessary to explain the data in the Einstein-de Sitter universe. If the popular Λ-dominated universe is taken for granted, our result then gives a strong constraint on the number evolution of giant elliptical or early-type galaxies to z~1-2 that must be met by any models in the hierarchically clustering universe, since such galaxies are the dominant population in this magnitude range (K<~22.5). A number evolution with η~1 is already difficult to reconcile with the data in this universe. On the other hand, number evolution of late-type galaxies and/or dwarf galaxies, which has been suggested by previous studies of optical galaxies, is allowed from the data. In the fainter magnitude range of K>~22.5, we found a slight excess of observed counts over the prediction of the PLE model when elliptical galaxies are treated as a single population. We

  4. Characterization and Application of a Grazing Angle Objective for Quantitative Infrared Reflection Microspectroscopy

    NASA Technical Reports Server (NTRS)

    Pepper, Stephen V.

    1995-01-01

    A grazing angle objective on an infrared microspectrometer is studied for quantitative spectroscopy by considering the angular dependence of the incident intensity within the objective's angular aperture. The assumption that there is no angular dependence is tested by comparing the experimental reflectance of Si and KBr surfaces with the reflectance calculated by integrating the Fresnel reflection coefficient over the angular aperture under this assumption. Good agreement was found, indicating that the specular reflectance of surfaces can straight-forwardly be quantitatively integrated over the angular aperture without considering non-uniform incident intensity. This quantitative approach is applied to the thickness determination of dipcoated Krytox on gold. The infrared optical constants of both materials are known, allowing the integration to be carried out. The thickness obtained is in fair agreement with the value determined by ellipsometry in the visible. Therefore, this paper illustrates a method for more quantitative use of a grazing angle objective for infrared reflectance microspectroscopy.

  5. The development of ground-based infrared multi-object spectrograph based on the microshutter array

    NASA Astrophysics Data System (ADS)

    Moon, Dae-Sik; Sivanandam, Suresh; Kutyrev, Alexander S.; Moseley, Samuel H.; Graham, James R.; Roy, Aishwarya

    2014-07-01

    We report on our development of a near-infrared multi-object spectrograph for ground-based applications using the micro-shutter array, which was originally developed for the Near Infrared Spectrograph of the James Webb Space Telescope. The micro-shutter array in this case acts as a source selector at a reimaged telescope focal plane. The developed spectrograph will be implemented either with ground-layer adaptive optics system or multi-conjugate adaptive optics system on a large telescope. This will enable for the first time fully reconfigurable infrared multi-object spectroscopy with adaptive optics systems. We envision studying diverse astronomical objects with our spectrograph, including high-redshift galaxies, galaxy clusters and super star clusters.

  6. Spatiotemporal saliency model for small moving object detection in infrared videos

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Ning, Chen; Xu, Lizhong

    2015-03-01

    In this paper, a novel spatiotemporal saliency model based on three-dimensional Difference-of-Gaussians filters is proposed for small moving object detection in infrared videos. First, instead of utilizing the spatial Difference-of-Gaussians (DoG) filter which has been used to build saliency model for static images, we propose to extend the spatial DoG filter to construct three-dimensional (3D) Difference-of-Gaussians filters for measuring the center-surround difference in the spatiotemporal receptive field. Second, an effective spatiotemporal saliency model is generated based on these filters. This model provides a good basis for accurate and robust infrared small moving object detection. Experimental results show that the proposed saliency model consistently outperforms state-of-the-art saliency models for infrared moving object detection under various complex backgrounds.

  7. Spectrophotometry of faint comets: The asteroid approach

    NASA Technical Reports Server (NTRS)

    Degewij, J.

    1981-01-01

    Observing programs at optical (0.35-0.8 micron) and near-infrared (1.1-2.4 micron) wavelengths, directed at the acquisition of reflection spectra of faint and distant comets, are described. The ultimate goal is to obtain spectrophotometric measurements of comets for which a significant part of the light is expected to be reflected by the solid surface of the nucleus.

  8. Infrared Telescope Facility's Spectrograph Observations of Human-Made Space Objects

    NASA Technical Reports Server (NTRS)

    Abercromby, K.; Buckalew, B.; Abell, P.; Cowardin, H.

    2015-01-01

    Presented here are the results of the Infrared Telescope Facility (IRTF) spectral observations of human-made space objects taken from 2006 to 2008. The data collected using the SpeX infrared spectrograph cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 20 different orbiting objects at or near the geosynchronous (GEO) regime. Four of the objects were controlled spacecraft, seven were non-controlled spacecraft, five were rocket bodies, and the final four were cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials, thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons, silicon, and thermal emission. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels, whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give excellent indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. However, based on the current state of the comparison between the observations and the laboratory data, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.

  9. The Hubble Space Telescope Wide Field Camera 3 Early Release Science Data: Panchromatic Faint Object Counts From 0.2-2 Micron To Ab=26-27 Mag

    NASA Astrophysics Data System (ADS)

    Windhorst, Rogier A.; McCarthy, P.; Cohen, S.; Ryan, R.; Driver, S.; Hathi, N.; Koekemoer, A.; Mechtley, M.; O'Connell, R.; Rutkowski, M.; Yan, H.; SOC, WFC3

    2010-01-01

    We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early Release Science (ERS) observations in the GOODS-South field. The new WFC3 ERS data provide calibrated, drizzled mosaics with FHWM=0.07--0.15" in the near-UV (filters F225W, F275W, and F336W) and near-IR (F098W, F125W, and F160W) in typically 2 orbits per filter. Together with the existing HST/ACS GOODS-S mosaics in the BVi'z' filters, the 10-band ERS data cover 40-50 sq. arcmin to AB=26-27.0 mag (10-sigma for point sources). In this poster, we describe the: (1) scientific rationale, data taking and reduction procedures of the WFC3 ERS mosaics; (2) object cataloging and star-galaxy separation techniques used in these 10 different filters; (3) reliability and completeness of the 10-band object catalogs from the ERS mosaics; (4) object counts in 10 different filters from 0.2-1.7 microns to AB=26.0-27.0 mag; and (5) the full-color 10-band ERS images. We discuss the panchromatic structure for a variety of interesting ERS objects at intermediate redshifts (z=0.5-3), including examples of galaxies with nuclear star-forming rings, bars, or weak AGN activity, UV-dropout galaxies at redshifts z=2-3, and objects of other interesting appearance. The 10-band panchromatic ERS data base is very rich in morphological structure at all restframe wavelengths where young or older stars shine during the peak epoch in the cosmic star-formation rate (at z=1-2). This work is based on ERS observations made by the WFC3 Scientific Oversight Committee. We are grateful to the Space Telescope Science Institute Director for awarding Director's Discretionary time for this program. Support for HST program 11359 was provided by NASA through grants GO-11359.0*.A from STScI, which is operated by AURA under NASA contract NAS 5-26555. We dedicate this paper to the memory of the STS-107 Columbia Shuttle astronauts, and of Dr. Rodger Doxsey.

  10. A substation infrared temperature monitoring and warning system with object separation and image registration

    NASA Astrophysics Data System (ADS)

    Lin, Lihua; Wu, Dongmei; Liu, Jian; Zhang, Xinghua

    2010-08-01

    To find the defects of the apparatus in a substation in the early stage, an infrared temperature monitoring and warning system is established. This system can monitor the electrical equipment automatically the movement condition. The systemic circulation gathers the transformer substation electrical equipment the infrared imagery, the extraction goal equipment temperature information, and with the history database creation connection, the synthesis distinguishes the equipment failure information. In view of image gathering when because the mechanical drive creates the deviation, proposed one kind of object-oriented division and the image matching adjustment algorithm, first carries on the object division and the configuration definition to the image, then uses based on the phase correlation carries on the matching with the Harris vertex match image matching method to the deviation image. In this paper, a infrared remote-viewing image registration based on phase correlation and feature points matching is presented. Several experiments illustrate that this method has a good performance of reliability and accuracy.

  11. New method for moving objects segmentation based on human vision perception in infrared video

    NASA Astrophysics Data System (ADS)

    Min, Chaobo

    2013-07-01

    A new method for moving object segmentation based on human vision perception in infrared video is proposed. In this paper, we introduce a new region growing method to achieve the accurate and complete segmentation of the moving objects. At first, the ideal seeds of every moving object are extracted based on the "hole" effect of temporal difference, respectively. At the next step, on the basis of the consideration that human vision system (HVS) is most sensitive to the local contrast between targets and surrounding, we proposed a metric for "good" infrared target segmentation based on human vision perception. And according to this metric, a search method based on fine and rough adjustment is applied to determine the best growing threshold for every moving object. The segmented mask of every moving object is grown from the relevant seeds with the best growing threshold. At last, the segmented masks of all moving objects are merged into a complete segmented mask. Experimental results show that the proposed method is superior and effective on segmentation of moving object in infrared video.

  12. The Lack of Torus Emission from BL Lacertae Objects: An Infrared View of Unification with WISE

    NASA Astrophysics Data System (ADS)

    Plotkin, Richard M.; Anderson, Scott F.; Brandt, W. N.; Markoff, Sera; Shemmer, Ohad; Wu, Jianfeng

    2012-02-01

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number (~102) of BL Lac objects—low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the "nature versus nurture" debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  13. OBJECT X: THE BRIGHTEST MID-INFRARED POINT SOURCE IN M33

    SciTech Connect

    Khan, Rubab; Stanek, K. Z.; Kochanek, C. S.; Bonanos, A. Z. E-mail: kstanek@astronomy.ohio-state.edu E-mail: bonanos@astro.noa.gr

    2011-05-01

    We discuss the nature of the brightest mid-IR point source (which we dub Object X) in the nearby galaxy M33. Although multi-wavelength data on this object have existed in the literature for some time, it had not previously been recognized as the most luminous mid-IR object in M33 because it is entirely unremarkable in both optical and near-IR light. In the Local Group Galaxies Survey, Object X is a faint red source visible in VRI and H{alpha} but not U or B. It was easily seen at JHK{sub s} in the Two Micron All Sky Survey. It is the brightest point source in all four Spitzer IRAC bands and is also visible in the MIPS 24 {mu}m band. Its bolometric luminosity is {approx}5 x 10{sup 5} L{sub sun}. The source is optically variable on short timescales (tens of days) and is also slightly variable in the mid-IR, indicating that it is a star. Archival photographic plates (from 1949 and 1991) show no optical source, so the star has been obscured for at least half a century. Its properties are similar to those of the Galactic OH/IR star IRC+10420, which has a complex dusty circumstellar structure resulting from episodic low-velocity mass ejections. We propose that Object X is an M {approx}> 30 M{sub sun} evolved star obscured in its own dust ejected during episodic mass-loss events over at least {approx}half a century. It may emerge from its current ultra-short evolutionary phase as a hotter post-red-supergiant star analogous to M33 Var A. The existence and rarity of such objects can be an important probe of a very brief yet eventful stellar evolutionary phase.

  14. Technical considerations for designing low-cost, long-wave infrared objectives

    NASA Astrophysics Data System (ADS)

    Desroches, Gerard; Dalzell, Kristy; Robitaille, Blaise

    2014-06-01

    With the growth of uncooled infrared imaging in the consumer market, the balance between cost implications and performance criteria in the objective lens must be examined carefully. The increased availability of consumer-grade, long-wave infrared cameras is related to a decrease in military usage but it is also due to the decreasing costs of the cameras themselves. This has also driven up demand for low-cost, long-wave objectives that can resolve smaller pixels while maintaining high performance. Smaller pixels are traditionally associated with high cost objectives because of higher resolution requirements but, with careful consideration of all the requirements and proper selection of materials, costs can be moderated. This paper examines the cost/performance trade-off implications associated with optical and mechanical requirements of long-wave infrared objectives. Optical performance, f-number, field of view, distortion, focus range and thermal range all affect the cost of the objective. Because raw lens material cost is often the most expensive item in the construction, selection of the material as well as the shape of the lens while maintaining acceptable performance and cost targets were explored. As a result of these considerations, a low-cost, lightweight, well-performing objective was successfully designed, manufactured and tested.

  15. Polarization state imaging in long-wave infrared for object detection

    NASA Astrophysics Data System (ADS)

    Bieszczad, Grzegorz; Gogler, Sławomir; Krupiński, Michał

    2013-10-01

    The article discusses the use of modern imaging polarimetry from the visible range of the spectrum to the far infrared. The paper presents the analyzes the potential for imaging polarimetry in the far infrared for remote sensing applications. In article a description of measurement stand is presented for examination of polarization state in LWIR. The stand consists of: infrared detector array with electronic circuitry, polarizer plate and software enabling detection method. The article also describes first results of measurements in presented test bed. Based on these measurements it was possible to calculate some of the Stokes parameters of radiation from the scene. The analysis of the measurement results show that the measurement of polarization state can be used to detect certain types of objects. Measuring the degree of polarization may allow for the detection of objects on an infrared image, which are not detectable by other techniques, and in other spectral ranges. In order to at least partially characterize the polarization state of the scene it is required to measure radiation intensity in different configurations of the polarizing filter. Due to additional filtering elements in optical path of the camera, the NETD parameter of the camera with polarizer in proposed measurement stand was equal to about 240mK. In order to visualize the polarization characteristics of objects in the infrared image, a method of imaging measurement results imposing them on the thermal image. Imaging of measurement results of radiation polarization is made by adding color and saturation to black and white thermal image where brightness corresponds to the intensity of infrared radiation.

  16. Image processing techniques for detection of buried objects with infrared images

    NASA Astrophysics Data System (ADS)

    Cerón-Correa, Alexander

    2006-01-01

    This document describes the principles of infrared thermography and its application to humanitarian demining in the world as well as the factors influencing its application in a country like Colombia which suffers badly the problem posed by antipersonnel mines. The main factors that affect the images taken by different sensors are: day time, mine size and material, installation angle, object's burial depth, moisture, emissivity, wind, rain, as well as other objects in the proximity shadowing the images. Infrared image processing methods and results of tests done in different sites of the country such as Cartagena, Bogota, and Tolemaida are also shown. Finally, a method for the detection of the presence of a buried object is presented with its successful results.

  17. A bio-inspired infrared imager with on chip object computation

    NASA Astrophysics Data System (ADS)

    McCarley, Paul L.; Caulfield, John T.

    2014-06-01

    This paper discusses a Biologically Inspired Shortwave Infrared (SWIR) imager that performs on chip object detection using temporal and spatial processing embedded in the imager's readout integrated circuit (ROIC). The sensor circuit is designed to detect pixel level intensity changes and correlate the change with nearby intensity changes using multiple thresholding criteria to output object exceedances. The sensor is capable of automatically outputting both normal video and also a reduced data set of binarized exceedances. Therefore this SWIR sensor with onboard temporal spatial sensing should be well suited to both manned and unmanned sensing scenarios which could benefit from automated object detection and reduced data sets.

  18. Machine learning in infrared object classification - an all-sky selection of YSO candidates

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Zahorecz, Sarolta; Toth, L. Viktor; Magnus McGehee, Peregrine; Kun, Maria

    2015-08-01

    Object classification is a fundamental and challenging problem in the era of big data. I will discuss up-to-date methods and their application to classify infrared point sources.We analysed the ALLWISE catalogue, the most recent public source catalogue of the Wide-field Infrared Survey Explorer (WISE) to compile a reliable list of Young Stellar Object (YSO) candidates. We tested and compared classical and up-to-date statistical methods as well, to discriminate source types like extragalactic objects, evolved stars, main sequence stars, objects related to the interstellar medium and YSO candidates by using their mid-IR WISE properties and associated near-IR 2MASS data.In the particular classification problem the Support Vector Machines (SVM), a class of supervised learning algorithm turned out to be the best tool. As a result we classify Class I and II YSOs with >90% accuracy while the fraction of contaminating extragalactic objects remains well below 1%, based on the number of known objects listed in the SIMBAD and VizieR databases. We compare our results to other classification schemes from the literature and show that the SVM outperforms methods that apply linear cuts on the colour-colour and colour-magnitude space. Our homogenous YSO candidate catalog can serve as an excellent pathfinder for future detailed observations of individual objects and a starting point of statistical studies that aim to add pieces to the big picture of star formation theory.

  19. Circumstellar Environments of Luminous Infrared Stellar Objects in the Magellanic Clouds

    NASA Technical Reports Server (NTRS)

    Azari, Abigail; Sahai, Raghvendra

    2011-01-01

    Young stars are formed out of the interstellar medium (ISM) which is replenished by mass loss rates from evolved stars. Circumstellar matter around young and evolved stellar objects usually emits energy in the infrared (IR) wavelength range as the matter is heated by the central star. Surveys of the Magellanic Clouds with the Spitzer Space Telescope in the 3.6-160 micron range have previously been completed. These surveys have led to catalogs of infrared sources: which include HII regions, young stars, super giants, asymptotic giant branch (AGB) stars, post-asymptotic giant branch (post-AGB) stars, and planetary nebulae. The utility of such surveys can be improved upon by using Hubble Space Telescope (HST) data. HST provides higher angular resolution than Spitzer and has allowed for more detailed investigation of these luminous IR objects. This project used previously obtained HST archival data to examine luminous IR objects at optical wavelengths. This allows for the reclassification of stellar objects previously thought as one type of object or in a particular stage of their stellar evolution. An overall objective of this project included looking for extended nebulosity around evolved stars to better understand the life cycle of such objects and classify these nebulae by shape.

  20. Near-infrared (JHK) spectroscopy of young stellar and substellar objects in orion

    SciTech Connect

    Ingraham, P.; Albert, L.; Doyon, R.; Artigau, E.

    2014-02-10

    We performed low-resolution (R ∼ 40) near-infrared (0.9-2.4 μm) multi-object spectroscopy of 240 isolated point sources having apparent H-band magnitudes between 9 and 18 in the central 5' × 6' of the Orion Trapezium cluster. The observations were performed over four nights at the Canada-France-Hawaii Telescope using the visiting instrument SIMON, an infrared imager and multi-object spectrograph. We present the spectra of 104 objects with accurately derived spectral types including 7 new objects having masses below the hydrogen-burning limit, and 6 objects with masses below the deuterium-burning limit. The spectral classification is performed by fitting previously classified spectral templates of dwarf stars (K4-M3) and optically classified young stellar and substellar objects (M4-L0), to the entire 0.9-2.4 μm spectral energy distribution in order to assign a spectral type and visual extinction for each object. Of the 104 objects studied, 44 have been previously classified spectroscopically using various techniques. We perform a rigorous comparison between the previous classifications and our own and find them to be in good agreement. Using the dereddened H-band magnitudes, the classified objects are used to create an Hertzsprung-Russell diagram for the cluster. We find that the previous age estimates of ∼1 Myr to be consistent with our results. Consistent with previous studies, numerous objects are observed to have luminosities several magnitudes above the 1 Myr isochrone. Numerous objects exhibiting emission features in the J band are also reported.

  1. Near-infrared observations of young stellar objects in the Rho Ophiuchi dark cloud

    NASA Technical Reports Server (NTRS)

    Greene, Thomas P.; Young, Erick T.

    1992-01-01

    We have conducted an imaging survey of 1.4 sq pc of the Rho Ophiuchi dark cloud in the J, H, and K near-infrared photometric bands. Approximately 337 of our 481 detected sources are associated with the cloud, and we estimate that 48 percent of these have near-infrared excesses, indicative of disks or circumstellar material surrounding these young stellar objects (YSOs). The K-band luminosity function is significantly different in different regions of our survey area, suggesting that YSOs in these regions have different ages or mass functions. We estimate that the entire survey area has a high star-formation efficiency, at roughly 23 percent. Finally, our many newly detected sources provide a relatively large, uniformly sensitive sample of objects for study at longer wavelengths to better determine true source luminosities and evolutionary lifetimes.

  2. Faint Object Spectrograph (FOS) early performance

    NASA Technical Reports Server (NTRS)

    Harms, Richard; Fitch, John

    1991-01-01

    The on-orbit performance of the HST + FOS instrument is described and illustrated with examples of initial scientific results. The effects of the spherical aberration from the misfiguring of the HST primary mirror upon isolated point sources and in complex fields such as the nuclei of galaxies are analyzed. Possible means for eliminating the effects of spherical aberration are studied. Concepts include using image enhancement software to extract maximum spatial and spectral information from the existing data as well as several options to repair or compensate for the HST's optical performance. In particular, it may be possible to install corrective optics into the HST which will eliminate the spherical aberration for the FOS and some of the other instruments. The more promising ideas and calculations of the expected improvements in performance are briefly described.

  3. A novel objective sour taste evaluation method based on near-infrared spectroscopy.

    PubMed

    Hoshi, Ayaka; Aoki, Soichiro; Kouno, Emi; Ogasawara, Masashi; Onaka, Takashi; Miura, Yutaka; Mamiya, Kanji

    2014-05-01

    One of the most important themes in the development of foods and drinks is the accurate evaluation of taste properties. In general, a sensory evaluation system is frequently used for evaluating food and drink. This method, which is dependent on human senses, is highly sensitive but is influenced by the eating experience and food palatability of individuals, leading to subjective results. Therefore, a more effective method for objectively estimating taste properties is required. Here we show that salivary hemodynamic signals, as measured by near-infrared spectroscopy, are a useful objective indicator for evaluating sour taste stimulus. In addition, the hemodynamic responses of the parotid gland are closely correlated to the salivary secretion volume of the parotid gland in response to basic taste stimuli and respond to stimuli independently of the hedonic aspect. Moreover, we examined the hemodynamic responses to complex taste stimuli in food-based solutions and demonstrated for the first time that the complicated phenomenon of the "masking effect," which decreases taste intensity despite the additional taste components, can be successfully detected by near-infrared spectroscopy. In summary, this study is the first to demonstrate near-infrared spectroscopy as a novel tool for objectively evaluating complex sour taste properties in foods and drinks. PMID:24474216

  4. Faint dwarfs in nearby groups

    SciTech Connect

    Speller, Ryan; Taylor, James E. E-mail: taylor@uwaterloo.ca

    2014-06-20

    The number and distribution of dwarf satellite galaxies remain a critical test of cold dark matter-dominated structure formation on small scales. Until recently, observational information about galaxy formation on these scales has been limited mainly to the Local Group. We have searched for faint analogues of Local Group dwarfs around nearby bright galaxies, using a spatial clustering analysis of the photometric catalog of the Sloan Digital Sky Survey (SDSS) Data Release 8. Several other recent searches of SDSS have detected clustered satellite populations down to Δm{sub r} ≡ (m{sub r,} {sub sat} – m{sub r,} {sub main}) ∼ 6-8, using photometric redshifts to reduce background contamination. SDSS photometric redshifts are relatively imprecise, however, for faint and nearby galaxies. Instead, we use angular size to select potential nearby dwarfs and consider only the nearest isolated bright galaxies as primaries. As a result, we are able to detect an excess clustering signal from companions down to Δm{sub r} = 12, 4 mag fainter than most recent studies. We detect an overdensity of objects at separations <400 kpc, corresponding to about 4.6 ± 0.5 satellites per central galaxy, consistent with the satellite abundance expected from the Local Group, given our selection function. Although the sample of satellites detected is incomplete by construction, since it excludes the least and most compact dwarfs, this detection provides a lower bound on the average satellite luminosity function, down to luminosities corresponding to the faintest ''classical'' dwarfs of the Local Group.

  5. THE LACK OF TORUS EMISSION FROM BL LACERTAE OBJECTS: AN INFRARED VIEW OF UNIFICATION WITH WISE

    SciTech Connect

    Plotkin, Richard M.; Markoff, Sera; Anderson, Scott F.; Brandt, W. N.; Wu Jianfeng; Shemmer, Ohad

    2012-02-15

    We use data from the Wide-Field Infrared Survey Explorer (WISE) to perform a statistical study on the mid-infrared (IR) properties of a large number ({approx}10{sup 2}) of BL Lac objects-low-luminosity active galactic nuclei (AGNs) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions. In other BL Lac objects, however, the jet is not strong enough to completely dilute the rest of the AGN emission. We do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. The lack of observable torus emission is consistent with suggestions that BL Lac objects are fed by radiatively inefficient accretion disks. Implications for the 'nature versus nurture' debate for FR I and FR II radio galaxies are briefly discussed. Our study supports the notion that, beyond orientation, accretion rate plays an important role in AGN unification.

  6. Safe VISITOR: visible, infrared, and terahertz object recognition for security screening application

    NASA Astrophysics Data System (ADS)

    May, T.; Zieger, G.; Anders, S.; Zakosarenko, V.; Meyer, H.-G.; Schubert, M.; Starkloff, M.; Rößler, M.; Thorwirth, G.; Krause, U.

    2009-05-01

    Security solutions with the purpose to detect hidden objects underneath the clothing of persons are desired in many environments. With the variety of application scenarios criteria like flexibility and mobility become more important. So, many developments trend to focus on cameras, which can image scenes from a distance. This new generation of tools will have the advantage of hidden operation, which is believed by experts to add to the security because of its unpredictability. Such stand-off cameras do have some divergent requirements compared to mm-wave portal scanners. They will benefit from shorter wavelengths because of the higher optical resolution. In contrast to that, the needed transmission properties might become impractical at higher frequencies. A commonly accepted compromise is the use of wavelengths around 0.5mm. However, for stand-off cameras without oversized optical apertures, a resolution around 1cm is a practical limit. For our security camera "Safe VISITOR" (Safe VISible, Infrared and Terhaertz Object recognition) we have chosen to combine images from three different camera modules: a CCD for visible light, a microbolometer for long infrared (14μm) and a superconducting bolometer for 870μm. This combines the highest optical resolution (visible), the unprecedented temperature resolution at infrared and the almost perfect transmission at terahertz. We have built a first prototype and tested it in a field trial. We will present experimental results and try to assess the false error rate of our system.

  7. A multifrequency radio continuum and IRAS faint source survey of markarian galaxies

    NASA Technical Reports Server (NTRS)

    Bicay, M. D.; Kojoian, G.; Seal, J.; Dickinson, D. F.; Malkan, M. A.

    1995-01-01

    Results are presented from a multifrequency radio continumm survey of Markarian galaxies (MRKs) and are supplemented by IRAS infrared data from the Faint Source Survey. Radio data are presented for 899 MRKs observed at nu = 4.755 GHz with the National Radio Astronomy Observatory (NRAO)-Green Bank 300 foot (91 m) telescope, including nearly 88% of those objects in Markarian lists VI-XIV. In addition, 1.415 GHz measurements of 258 MRKs, over 30% of the MRKs accessible from the National Aeronomy and Ionosphere Center (NAIC)-Arecibo, are reported. Radio continuum observations of smaller numbers of MRKs were made at 10.63 GHz and at 23.1 GHz and are also presented. Infrared data from the IRAS Faint Source Survey (Ver. 2) are presented for 944 MRKs, with reasonably secure identifications extracted from the NASA/IPAC Extragalactic Database. MRKs exhibit the same canonical infrared characteristics as those reported for various other galaxy samples, that is well-known enhancement of the 25 micrometer/60 micrometer color ratio among Seyfert MRKs, and a clear tendency for MRKs with warmer 60 micrometer/100 micrometer colors to also possess cooler 12 micrometer/25 micrometer colors. In addition, non-Seyfert are found to obey the well-documented infrared/radio luminosity correlation, with the tightest correlation seen for starburst MRKs.

  8. CENTAURS AND SCATTERED DISK OBJECTS IN THE THERMAL INFRARED: ANALYSIS OF WISE/NEOWISE OBSERVATIONS

    SciTech Connect

    Bauer, James M.; Grav, Tommy; Blauvelt, Erin; Collaboration: WISE Team; PTF Team; and others

    2013-08-10

    The Wide-field Infrared Survey Explorer (WISE) observed 52 Centaurs and scattered disk objects (SDOs) in the thermal infrared, including 15 new discoveries. We present analyses of these observations to estimate sizes and mean optical albedos. We find mean albedos of 0.08 {+-} 0.04 for the entire data set. Thermal fits yield average beaming parameters of 0.9 {+-} 0.2 that are similar for both SDO and Centaur sub-classes. Biased cumulative size distributions yield size-frequency distribution power law indices of {approx}-1.7 {+-} 0.3. The data also reveal a relation between albedo and color at the 3{sigma} level. No significant relation between diameter and albedos is found.

  9. Results and analyses of faint field galaxy surveys with the Keck Telescope

    NASA Astrophysics Data System (ADS)

    Hogg, D. W.

    1996-12-01

    A large collaboration at Caltech has been using the Keck and other telescopes to perform UBVRIKL imaging and take spectra of faint galaxies. The spectroscopic samples contain several hundred objects to K=20 mag or R=24 mag and the imaging samples contain thousands of sources to R~ 27. Faint field galaxies are found to be strongly clustered in velocity space; the angular coherence, masses and morphologies in configuration space of these structures are investigated. In cooperation with the University of Hawaii group, the luminosity function of galaxies is computed in the near-infrared; strong evolution is found in the number of low-luminosity galaxies to z~ 1, although the statistical properties of high-luminosity objects are relatively constant. A range of models for the faint galaxy counts are constructed, not on the basis of a priori information about galaxy properties (from, say, cosmogonic theory) but rather by ``inverting'' the data under a range of qualitatively distinct simplifying assumptions. Predictions are made for ongoing or future imaging and spectroscopy surveys which will clearly distinguish the models. The prospects for a ``meta-analysis'' of a large collection of heterogeneous surveys to create consistent galaxy evolution models from z=0 to the highest observed redshifts are discussed.

  10. Passive signatures concealed objects recorded by multispectral and hyperspectral systems in visible, infrared and terahertz range

    NASA Astrophysics Data System (ADS)

    Kastek, Mariusz; Kowalski, Marcin; Polakowski, Henryk; Lagueux, Philippe; Gagnon, Marc-André

    2014-06-01

    Risks to the safety of public zones (generally available for people) are related mainly to the presence of hidden dangerous objects (such as knives, guns, bombs etc.) and their usage. Modern system for the monitoring of such zones attempt to detect dangerous tools using multispectral cameras working in different spectral ranges: the visible radiation, near, medium and long range infrared and recently also in terahertz range. In order to develop methods and algorithms to detect hidden objects it is necessary to determine the thermal signatures of such objects of interest. The laboratory measurements were conducted to determine the thermal signatures of dangerous tools hidden under various clothes in different ambient conditions. Cameras used for measurements were working in spectral range 0.6-12.5 µm. An infrared imaging Fourier transform spectroradiometer was also used, working in spectral range 7.7-11.7 µm. Analysis of registered thermograms and hyperspectral datacubes has yielded the thermal signatures for: two types of guns, two types of knives and home-made explosive bombs. The determined thermal signatures will be used in the development of method and algorithms of image analysis implemented in proposed monitoring systems.

  11. Characterization of high proper motion objects from the wide-field infrared survey explorer

    SciTech Connect

    Luhman, K. L.; Sheppard, Scott S.

    2014-06-01

    We present an analysis of high proper motion objects that we have found in a recent study and in this work with multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE). Using photometry and proper motions from the Two Micron All-Sky Survey and WISE, we have identified the members of this sample that are likely to be late-type, nearby, or metal-poor. We have performed optical and near-infrared spectroscopy on 41 objects, from which we measure spectral types that range from M4-T2.5. This sample includes 11 blue L dwarfs and 5 subdwarfs; the latter were also classified as such in the recent study by Kirkpatrick and coworkers. Based on their spectral types and photometry, several of our spectroscopic targets may have distances of <20 pc with the closest at ∼12 pc. The tangential velocities implied by the spectrophotometric distances and proper motions indicate that four of the five subdwarfs are probably members of the Galactic halo while several other objects, including the early-T dwarf WISE J210529.08–623558.7, may belong to the thick disk.

  12. Objective assessment of biomagnetic devices and alternative clinical therapies using infrared thermal imaging

    NASA Astrophysics Data System (ADS)

    Rockley, Graham J.

    2001-03-01

    The overwhelming introduction of magnetic devices and other alternative therapies into the health care market prompts the need for objective evaluation of these techniques through the use of infrared thermal imaging. Many of these therapies are reported to promote the stimulation of blood flow or the relief of pain conditions. Infrared imaging is an efficient tool to assess such changes in the physiological state. Therefore, a thermal imager can help document and substantiate whether these therapies are in fact providing an effective change to the local circulation. Thermal images may also indicate whether the change is temporary or sustained. As a specific case example, preliminary findings will be presented concerning the use of magnets and the effect they have on peripheral circulation. This will include a discussion of the recommended protocols for this type of infrared testing. This test model can be applied to the evaluation of other devices and therapeutic procedures which are reputed to affect circulation such as electro acupuncture, orthopedic footwear and topical ointments designed to relieve pain or inflammation.

  13. Infrared Spectroscopy and Young Stellar Objects: Characterizing the Dust and Gas in Circumstellar Disks

    NASA Astrophysics Data System (ADS)

    Kruger, Andrew James

    In this dissertation, I describe my work in infrared spectroscopy and in studying the circumstellar disks around young stellar objects. In the first part, I detail an electronic component I designed for the Texas Echelon Cross Echelle Spectrograph (TEXES), which has acted as a visiting instrument on Gemini North and the NASA Infrared Telescope Facility. In order to detect the incoming infrared flux, a bias voltage is applied across the detector to sweep out the photo-excited electrons. If the bias voltage is too weak, the electrons can recombine before being swept out, while a strong bias can create unstable photoconductive gain. The initial design of TEXES required the operator to open the electronics and change the bias voltage by hand. However, the optimal bias is not the same for different instrument modes, which wasted substantial observing time when changing instrument modes. In order to save future observing time, and to fulfill a precondition set by Gemini North for TEXES to act as a visiting instrument, I created an electronic component to change the detector bias from the computer control room. I investigate and characterize the optimal voltages for the Raytheon 2562 SiAs IBC "SIRTF" array for the different instrument modes used by TEXES. In the following sections, I describe our observing campaign using the Spitzer IRS module and three ground-based telescopes to investigate edge-on circumstellar disks and classical infrared companions. Observations of the terrestrial planet forming regions of circumstellar disks are difficult to obtain, but recent detections of molecular absorption originating from these regions have proven valuable for disk models. We were granted time with the Spitzer Space Telescope to observe seven targets classified as young stellar objects, likely with their disks seen edge-on, to search for molecular absorption features. We used ground-based telescopes, including Gemini South, W. M. Keck Observatory, and the European Southern

  14. THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. III. ANALYSIS OF 3CRR OBJECTS

    SciTech Connect

    Dicken, D.; Axon, D.; Robinson, A.; Kharb, P.; Tadhunter, C.; Morganti, R. E-mail: djasps@rit.ed E-mail: c.tadhunter@sheffield.ac.u

    2010-10-20

    We present Spitzer photometric data for a complete sample of 19 low-redshift (z< 0.1) 3CRR radio galaxies as part of our efforts to understand the origin of the prodigious mid- to far-infrared (MFIR) emission from radio-loud active galactic nuclei (AGNs). Our results show a correlation between AGN power (indicated by [O III]{lambda}5007 emission line luminosity) and 24 {mu}m luminosity. This result is consistent with the 24 {mu}m thermal emission originating from warm dust heated directly by AGN illumination. Applying the same correlation test for 70 {mu}m luminosity against [O III] luminosity we find this relation to suffer from increased scatter compared to that of 24 {mu}m. In line with our results for the higher-radio-frequency-selected 2 Jy sample, we are able to show that much of this increased scatter is due to heating by starbursts that boost the far-infrared emission at 70 {mu}m in a minority of objects (17%-35%). Overall this study supports previous work indicating AGN illumination as the dominant heating mechanism for MFIR emitting dust in the majority of low-to-intermediate redshift radio galaxies (0.03 < z < 0.7), with the advantage of strong statistical evidence. However, we find evidence that the low-redshift broad-line objects (z < 0.1) are distinct in terms of their positions on the MFIR versus [O III] correlations.

  15. Dust in BL Lac objects and Fanaroff-Riley radio galaxies: infrared region

    NASA Astrophysics Data System (ADS)

    Seal Braun, P.

    2015-12-01

    Here 28 BL Lac objects, 18 FR I type radio galaxies, 4 FR I/II type radio galaxies and 10 FR II type radio galaxies are studied from FIR (far infrared) to optical region (180 μm to 0.44 μm) to understand the nature of infrared emission from these objects and the physical properties of dust in the emitting region. Using the flux densities from 2MASS, IRAS, ISO, SCUBA (40 % samples), WISE All-sky Data, AKARI (10 % samples) data and optical (B) observations, the spectral energy distributions are constructed. FIR and NIR spectral indices (α_{FIR} and α_{NIR}) are estimated. The dust temperatures and dust masses of all the samples are estimated from FIR flux densities. The SEDs of most of the samples (90 %) show steep slopes from FIR to optical region and about 10 % of the samples show flat continuous spectra from FIR to NIR region. The SEDs of 80 % FR I type radio galaxies and 1 out of 4 FR I/II type radio galaxies and two RBLs show a bump in the NIR to optical region. The SEDs of these sources are compared with Radiative transfer models. From FIR to MIR region, the SEDs of 90 % of the objects studied here can be fitted to the models with luminosities L˜ 10^{9.5} L0, considering uncertainty from 10 % to 20 %. But the observable fluxes in the NIR region are higher and can be fitted to other models with higher L˜ 10^{12.5} L0. Since there is a difference in emission in NIR region, mainly for FR I radio galaxies, so the variation of apparent K magnitudes with logarithm of redshift z is also studied. The WISE colours, (W1 - W2) and (W2 - W3) are compared with isodensity contours. Comparing with radiative transfer models it can be suggested that, in the FIR and MIR region the infrared emission is from the dust containing large grains, small graphites and PAHs at temperature ˜50 K-100 K. In the NIR region hot dust is mainly due to small grains at temperature ˜1200 K and the emission is mainly from synchrotron radiation produced in the inner part of the relativistic

  16. Infrared object detection using global and local cues based on LARK

    NASA Astrophysics Data System (ADS)

    Qi, Wei; Han, Jing; Zhang, Yi; Bai, Lian-fa

    2016-05-01

    Object detection has become a challenging problem in computer vision. Locally Adaptive Regression Kernel (LARK) based detection methods are able to produce visually pleasing results without any training. We in this paper present an effective object detection method by exploring global and local cues based on LARK features. First, we encode the local context similarity by exploiting region Structural LARK (SLARK) features, which measure the likeness of a pixel to its surroundings in the query image and the test image. Second, a global constraint based on SLARK features via Heat equation is learned to detect similar features in the test image. Results from matrix cosine similarity are computed to estimate similar regions between these computed features. A compactness score is provided to refine these regions. Next, we detect the location of objects in the test image using non-maxima suppression. We show in experiments that the proposed method significantly outperforms other methods on the infrared image datasets, localizing the objects in the test images effectively.

  17. The Population of Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Gomez, Juan; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.

    2016-01-01

    The 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile has been used for spot surveys of the GEO orbital regime to study the population of optically faint GEO debris. The goal is to estimate the size of the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small size of the field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude have been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The observed detections have a wide range in characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections with variations in brightness, flashers, during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected size times albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm. The data in this paper was collected over the last several years using Magellan's IMACS camera in f/2 mode. The analysis shows the brightness bins for the observed GEO population as well as the periodicity of the flashers. All objects presented are correlated with the catalog: the focus of the paper will be on the uncorrelated, optically faint, objects. The goal of this project is to better characterize the faint debris population in GEO that access to a 6.5-m optical telescope in a superb site can provide.

  18. NEAR-INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN THE STAR FORMATION REGION CYGNUS OB7

    SciTech Connect

    Wolk, Scott J.; Rice, Thomas S.; Aspin, Colin

    2013-08-20

    We present an analysis of near-infrared time-series photometry in J, H, and K bands for about 100 epochs of a 1 Degree-Sign Multiplication-Sign 1 Degree-Sign region of the Lynds 1003/1004 dark cloud in the Cygnus OB7 region. Augmented by data from the Wide-field Infrared Survey Explorer, we identify 96 candidate disk bearing young stellar objects (YSOs) in the region. Of these, 30 are clearly Class I or earlier. Using the Wide-Field Imaging Camera on the United Kingdom Infrared Telescope, we were able to obtain photometry over three observing seasons, with photometric uncertainty better than 0.05 mag down to J Almost-Equal-To 17. We study detailed light curves and color trajectories of {approx}50 of the YSOs in the monitored field. We investigate the variability and periodicity of the YSOs and find the data are consistent with all YSOs being variable in these wavelengths on timescales of a few years. We divide the variability into four observational classes: (1) stars with periodic variability stable over long timescales, (2) variables which exhibit short-lived cyclic behavior, (3) long-duration variables, and (4) stochastic variables. Some YSO variability defies simple classification. We can explain much of the observed variability as being due to dynamic and rotational changes in the disk, including an asymmetric or changing blocking fraction, changes to the inner disk hole size, as well as changes to the accretion rate. Overall, we find that the Class I:Class II ratio of the cluster is consistent with an age of <1 Myr, with at least one individual, wildly varying source {approx}100, 000 yr old. We have also discovered a Class II eclipsing binary system with a period of 17.87 days.

  19. Spectroscopic surveys of faint blue stars

    NASA Technical Reports Server (NTRS)

    Wegner, Gary; Boley, Forrest I.; Swanson, Steven R.; Mcmahan, Robert K.

    1987-01-01

    Spectroscopy of 450 faint blue stars obtained with the spectrograph and intensified Reticon scanner on the 1.3 m telescope at the McGraw Hill Observatory located at Kitt Peak are examined. The study is limited to objects brighter than V = 17.0 in magnitude. It is found that the relative numbers of objects such as white dwarfs, QSOs and CVs in the Kisco survey (Noguchi et al. 1980) is similar to that in the survey of Green et al., (1986).

  20. An objective method for computing advective surface velocities from sequential infrared satellite images

    NASA Astrophysics Data System (ADS)

    Emery, W. J.; Thomas, A. C.; Collins, M. J.; Crawford, W. R.; Mackas, D. L.

    1986-11-01

    Using cross correlations between sequential infrared satellite images, an objective technique is developed to compute advective sea surface velocities. Cross correlations are computed in 32 × 32 pixel search (second image) and 22 × 22 template (first image) windows from gradients of sea surface temperature computed from the satellite images. Velocity vectors, computed from sequential images of the British Columbia coastal ocean, generally appear coherent and consistent with the seasonal surface current in the region. During periods of strong wind forcing, as indicated by maps of sea level pressure, the image advective velocities are stronger and more coherent spatially and appear to cross surface temperature gradients; when winds are weaker, the advective velocities correspond better with the infrared temperature patterns, suggesting the increased contribution of the geostrophic current to the surface flow. Velocities determined from coincident, near-surface drogued (5-10 m) buoys, positioned every half hour by internal LORAN-C units in mid-June, show excellent agreement with the image advective velocities. In addition, conductivity, temperature, and depth (CTD) measurements (taken during the buoy tracking) confirm the homogeneity of the upper 10 m, and CTD-derived geostrophic currents are consistent with both buoy and sequential image displacement velocities.

  1. Visible and infrared investigations of planet-crossing asteroids and outer solar system objects

    NASA Technical Reports Server (NTRS)

    Tholen, David J.

    1991-01-01

    A major effort was directed toward 951 Gaspra in preparation for the Galileo encounter in October 1991. Most of the observational work involved photometry, for purposes of investigating the rotational state and phase function of the asteroid to help plan the encounter, and for purposes of navigating the spacecraft to the object. Work was also done with radiometric data obtained with the IRTF at NASA's request, for which simultaneous visible photometry was acquired with the University of Hawaii 2.24-m telescope. The results from the observations made during the 1990 opposition were published by Goldader et al. The main results reported include a rotational period of 7.04246 hours, an absolute visual magnitude of 11.8026, a slope parameter of 0.285, an early estimate of a high obliquity, an infrared spectrum indicating an olivine-rich composition, and 13 astrometric positions.

  2. Near-Infrared Colors of the Binary Kuiper Belt Object 1998 WW31

    NASA Astrophysics Data System (ADS)

    Takato, Naruhisa; Fuse, Tetsuharu; Gaessler, Wolfgang; Goto, Miwa; Kanzawa, Tomio; Kobayashi, Naoto; Minowa, Yosuke; Oya, Shin; Pyo, Tae-Soo; Saint-Jacque, D.; Takami, Hideki; Terada, Hiroshi; Hayano, Yutaka; Iye, Masanori; Kamata, Yukiko; Tokunaga, A. T.

    2003-06-01

    We have measured near-infrared colors of the binary Kuiper Belt object (KBO) 1998 WW31 using the Subaru Telescope with adaptive optics. The satellite was detected near its perigee and apogee (0.18'' and 1.2'' apart from the primary). The primary and the satellite have similar H-K colors, while the satellite is redder than the primary in J-H. Combined with the R band magnitude previously published by Veillet et al., 2002, the color of the primary is consistent with that of optically red KBOs. The satellite's R-, J-, H-colors suggest the presence of ~1 μm absorption band due to rock-forming minerals. If the surface of the satellite is mainly composed by olivine, the satellite's albedo is higher value than the canonically assumed value of 4%.

  3. Comparison of broadband and hyperspectral thermal infrared imaging of buried threat objects

    NASA Astrophysics Data System (ADS)

    McFee, John E.; Achal, Steve B.; Diaz, Alejandra U.; Faust, Anthony A.

    2013-06-01

    Previous research by many groups has shown that broad-band thermal infrared (TIR) imagers can detect buried explosive threat devices, such as unexploded ordnance (UXO), landmines and improvised explosive devices (IEDs). Broad-band detection measures the apparent temperature - an average over the wave band of the product of the true soil surface temperature and the emissivity. Broad-band detection suffers from inconsistent performance (low signal, high clutter rates), due in part to diurnal variations, environmental and meteorological conditions, and soil surface effects. It has been suggested that hyperspectral TIR imaging might have improved performance since it can, in principle, allow extraction of the wavelength-dependent emissivity and the true soil surface temperature. This would allow the surface disturbance effects to be separated from the soil column (bulk) effects. A significant, and as yet unanswered, question is whether hyperspectral TIR images provide better detection capability (higher probability of detection and/or lower false alarm rate) than do broad-band thermal images. TIR hyperspectral image data of threat objects, buried and surface-laid in bare soil, were obtained in arid, desert-like conditions over full diurnal cycles for several days. Regions of interest containing threat objects and backgrounds were extracted throughout the time period. Simulated broad-band images were derived from the hyperspectral images. The diurnal variation of the images was studied. Hyperspectral was found to provide some advantage over broad-band imaging in detection of buried threat objects for the limited data set studied.

  4. The faint galaxy contribution to the diffuse extragalactic background light

    NASA Technical Reports Server (NTRS)

    Cole, Shaun; Treyer, Marie-Agnes; Silk, Joseph

    1992-01-01

    Models of the faint galaxy contribution to the diffuse extragalactic background light are presented, which are consistent with current data on faint galaxy number counts and redshifts. The autocorrelation function of surface brightness fluctuations in the extragalactic diffuse light is predicted, and the way in which these predictions depend on the cosmological model and assumptions of biasing is determined. It is confirmed that the recent deep infrared number counts are most compatible with a high density universe (Omega-0 is approximately equal to 1) and that the steep blue counts then require an extra population of rapidly evolving blue galaxies. The faintest presently detectable galaxies produce an interesting contribution to the extragalactic diffuse light, and still fainter galaxies may also produce a significant contribution. These faint galaxies still only produce a small fraction of the total optical diffuse background light, but on scales of a few arcminutes to a few degrees, they produce a substantial fraction of the fluctuations in the diffuse light.

  5. A Mid-Infrared Imaging Survey of Embedded Young Stellar Objects in the (rho) Ophiuchi Cloud Core

    NASA Technical Reports Server (NTRS)

    Barsony, Mary; Ressler, Michael E.; Marsh, Kenneth A.

    2005-01-01

    Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the (rho) Ophiuchi cloud are presented. Data were acquired at the Palomar 5m and at the Keck 10m telescopes with the MIRLIN and LWS instruments, at 0'.5 and 0'.25 resolutions, respectively. Of 172 survey objects, 85 were detected. Among the 22 multiple systems observed, 15 were resolved and their individual component fluxes determined. A plot of the frequency distribution of the detected objects with SED spectral slope shows that YSOs spend approx.4 x 10(exp 5) yr in the flat-spectrum phase, clearing out their remnant infall envelopes. Mid-infrared variability is found among a significant fraction of the surveyed objects and is found to occur for all SED classes with optically thick disks. Large-amplitude near-infrared variability, also found for all SED classes with optically thick disks, seems to occur with somewhat higher frequency at the earlier evolutionary stages. Although a general trend of mid-infrared excess and near-infrared veiling exists progressing through SED classes, with Class I objects generally exhibiting r(sub K) >= 1, flat-spectrum objects with r(sub K) >= 0.58, and Class III objects with r(sub K) =0, Class II objects exhibit the widest range of r(sub K) values, ranging from 0 <= r(sub K) <= 4.5. However, the highly variable value of veiling that a single source can exhibit in any of the SED classes in which active disk accretion can take place is striking and is direct observational evidence for highly time-variable accretion activity in disks. Finally, by comparing mid-infrared versus near-infrared excesses in a subsample with well-determined effective temperatures and extinction values, disk-clearing mechanisms are explored. The results are consistent with disk clearing proceeding from the inside out.

  6. Infrared near-Earth-object survey modeling for observatories interior to the Earth's orbit

    NASA Astrophysics Data System (ADS)

    Buie, M.

    2014-07-01

    The search for and dynamical characterization of the near-Earth population of objects (NEOs) has been a busy topic for surveys for many years. Most of the work thus far has been from ground-based optical surveys such as the Catalina Sky Survey and LINEAR. These surveys have essentially reached a complete inventory of objects down to 1 km diameter and have shown that the known objects do not pose any significant impact threat. Smaller objects are correspondingly smaller threats but there are more of them and fewer of them have so far been discovered. The next generation of surveys is looking to extend their reach down to much smaller sizes. From an impact risk perspective, those objects as small as 30--40 m are still of interest (similar in size to the Tunguska bolide). Smaller objects than this are largely of interest from a space resource or in-situ analysis efforts. A recent mission concept promoted by the B612 Foundation and Ball Aerospace calls for an infrared survey telescope in a Venus-like orbit, known as the Sentinel Mission. This wide-field facility has been designed to complete the inventory down to a 140 m diameter while also providing substantial constraints on the NEO population down to a Tunguska-sized object. I have been working to develop a suite of tools to provide survey modeling for this class of survey telescope. The purpose of the tool is to uncover hidden complexities that govern mission design and operation while also working to quantitatively understand the orbit quality provided on its catalog of objects without additional followup assets. The baseline mission design calls for a 6.5 year survey lifetime. This survey model is a statistically based tool for establishing completeness as a function of object size and survey duration. Effects modeled include the ability to adjust the field-of-regard (includes all pointing restrictions), field-of-view, focal plane array fill factor, and the observatory orbit. Consequences tracked include time

  7. a Faint and Lonely Brown Dwarf in the Solar Vicinity

    NASA Astrophysics Data System (ADS)

    1997-04-01

    La Silla, each covering a sky area of 5 o.5 x 5 o.5. When comparing plates of the same sky field obtained at time intervals of several years [1] , she was able to detect, among the hundreds of thousands of stellar images on the plates, a few faint ones whose positions had changed a little in the meantime. The search technique is based on the fact that such a shift is a good indicator of the object being relatively nearby. It must therefore also be intrinsically faint, i.e. a potential White Dwarf candidate. On every pair of plates, approximately twenty faint moving objects were detected with proper motions [2] of more than 0.25 arcsec per year. Indeed, follow-up spectroscopic observations showed that about 20 percent of these or about four per plate were White Dwarfs. Until now, a total of forty new White Dwarfs have been discovered during this very successful project, i.e. over ten times more than originally expected. And then - a Brown Dwarf! Caption to ESO PR Photo 11/97 [JPEG, 144k] ESO Press Photo 11/97 When checking two plates with a time inverval of 11 years, Maria Teresa Ruiz earlier this year discovered a very faint object in the southern constellation of Hydra (The Water-Snake), moving at 0.35 arcsec per year (cf. ESO Press Photo 11/97). In order to establish its true nature, she obtained its spectrum (in the visual to near-infrared region from wavelengths 450-1000 nm) on March 15 using the ESO 3.6-m telescope and the EFOSC1 spectrograph. Caption to ESO PR Photo 12/97 [GIF, 35k] ESO Press Photo 12/97 To her great surprise, the spectrum was of a type never seen before and certainly not that of a White Dwarf or any other easily identifiable type of star (cf. ESO Press Photo 12/97). In particular, there were no signs of spectral bands of titanium oxide (TiO) or vanadium oxide (VO) which are common in very cool stars, nor of the spectral lines seen in White Dwarfs. On the other hand, an absorption line of the short-lived element lithium was identified, as well

  8. Integration, testing, and performance of the Infrared Multi-Object Spectrometer

    NASA Astrophysics Data System (ADS)

    Ohl, Raymond G.; Connelly, Joseph A.; Boyle, Robert F.; Derro, Rebecca J.; Fitzgerald, Danette L.; Greenhouse, Matthew A.; Madison, Timothy J.; Mentzell, John E.; Nord, Brian; Sparr, Leroy M.; Hylan, Jason E.; Ray, Knute; MacKenty, John W.

    2004-09-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator-class instrument for the Kitt Peak National Observatory 2.1 m and Mayall 3.8 m telescopes. IRMOS is a near-IR (0.8--2.5 micron) spectrometer with low- to mid-resolving power (R = λ/Δλ = 300-3000). On the 3.8 m telescope, IRMOS produces simultaneous spectra of ~100 objects in its 2.8 ' 2.0 arcmin field of view using a commercial micro electro-mechanical systems (MEMS) digital micro-mirror device (DMD) from Texas Instruments. The multi-mirror array DMD operates as a real-time programmable slit mask. The all-reflective optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the DMD field stop, and the spectrograph images the DMD onto a large-format detector. The instrument operates at ~90 K, cooled by a single electro-mechanical cryocooler. The bench and all components are made from aluminum 6061. There are three cryogenic mechanisms. We describe laboratory integration and test of IRMOS before shipment to Kitt Peak National Observatory. We give an overview of the optical alignment technique and integration of optical, mechanical, electrical and cryogenic subsystems. We compare optical test results to model predictions of point spread function size. We discuss some lessons learned and conclude with a prediction for performance on the telescope.

  9. The Planning Process for Multi-Object Spectroscopy with the JWST Near-Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Beck, Tracy L.; Karakla, D. M.; Shyrokov, A.; Pontoppidan, K.; Soderblom, D. R.; Valenti, J. A.; Kassin, S. A.; Gilbert, K.; Blair, W. P.; Muzerolle, J.; Tumlinson, J.; Keyes, C. D.; Pavlovsky, C. M.; LeBlanc, T.

    2014-01-01

    The Near-Infrared Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) will have a powerful multi-object spectroscopy mode using four configurable Micro-Shutter Arrays (MSAs). The contiguous MSA shutters can be opened to form slits on astronomical targets, for simultaneous spectroscopy of up to 100 sources per exposure. The NIRSpec MSA shutters are in a fixed grid pattern, and careful analysis in the observation planning process will be crucial for optimal definition of science exposures. Our goal is to maximize the number of astronomical science sources observed in the fewest number of MSA slit configurations. We are developing algorithms in the NIRSpec MSA Planning Tool (MPT) to improve the quality of planned observations using several common science observing strategies as test use cases. For example, the needs for planning extremely deep exposures on a small number of JWST discovered z > 10 galaxy candidates will differ significantly from the requirements for planning spectral observations on a representative sample of stars from a galactic star cluster catalog. In this poster, we present a high level overview of our plans to develop and optimize the MPT for the JWST NIRSpec multi-object spectroscopy mode.

  10. Integration, Testing and Performance of the Infrared Multi-Object Spectrometer

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Connelly, Joseph A.; Boyle, Robert F.; Derro, Rebecca J.; Greenhouse, Matthew A.; Madison, Timothy J.; Mentzell, J. Eric; Sparr, Leroy M.; Hylan, Jason E.; Ray, Knute

    2003-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a principle investigator-class instrument for the Kitt Peak National Observatory 2.1 m and Mayall 3.8 m telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low-to mid-resolving power (R = lambda/delta lambda = 300 - 3000). On the 3.8 m telescope, IRMOS produces simultaneous spectra of approximately 100 objects in its approximately 3 x 2 arcmin field of view using a commercial micro electro-mechanical systems (MEMS) digital micro-mirror device (DMD) from Texas Instruments. The multi-mirror array DMD operates as a real-time programmable slit mask. The all-reflective optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the DMD field stop, and the spectrograph images the DMD onto a large-format detector. The instrument operates at approximately 80 K, cooled by a single electro-mechanical cryocooler. The bench and all components are made from aluminum 6061-T651. There are three cryogenic mechanisms. We describe laboratory integration and test of IRMOS before shipment to Kitt Peak. We give an overview of the optical alignment technique and integration of optical, mechanical, electrical and cryogenic subsystems. We compare optical test results to model predictions of point spread function size and morphology, contrast, and stray light. We discuss some lessons learned and conclude with a prediction for performance on the telescope.

  11. An Infrared Multi-Object Spectrograph (IRMS) with adaptive optics for TMT: the science case

    NASA Astrophysics Data System (ADS)

    Mobasher, Bahram; Crampton, David; Simard, Luc

    2010-07-01

    It has been recognized that a Near-Infrared Multi-object Spectrograph (IRMS) as one of the first light instrument on the Thirty Meter Telescope (TMT) would significantly increase the scientific capability of the observatory. The IRMS is planned to be a clone of the MOSFIRE instrument on the Keck telescope. As a result, we use the already available MOSFIRE design and expertise, significantly reducing the total cost and its development time. The IRMS will be a quasi diffraction limited multi-slit spectrograph with moderate resolution (R~4000), fed by Narrow-Field Infrared Adaptive Optics System (NFIRAOS). It images over the 2 arcmin diameter field of view of the NFIRAOS. There are a number of exceedingly important scientific questions, waiting to be addressed by the TMT/IRMS combination. Given its relatively small field of view, it is less affected by the sky background, which is a limiting factor in ground-based observations at near-IR wavelengths. The IRMS is the ideal instrument for studying spectroscopic properties of galaxies at the re-ionization epoch (z > 7), where the Lyman alpha line shifts to the near-ir wavelenghths. It can be used to measure rotation curves of spiral and velocity dispersion of elliptical galaxies at z~2-3 and hence, their spectroscopic mass. It can be used to search for population III stars via their spectroscopic signature and to perform measurement of spectroscopic lines at high redshifts, diagnostic of metallicity. Finally, IRMS allows measurement of the blue shifts in the rest-frame MgII line for high redshift galaxies, used to study the winds, leading to the feedback mechanism, responsible for quenching star formation activity in galaxies.

  12. MASSIVE YOUNG STELLAR OBJECTS IN THE GALACTIC CENTER. I. SPECTROSCOPIC IDENTIFICATION FROM SPITZER INFRARED SPECTROGRAPH OBSERVATIONS

    SciTech Connect

    An, Deokkeun; RamIrez, Solange V.; Boogert, A. C. Adwin; Sellgren, Kris; Arendt, Richard G.; Schultheis, Mathias; Cotera, Angela S.; Stolovy, Susan R.

    2011-08-01

    We present results from our spectroscopic study, using the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope, designed to identify massive young stellar objects (YSOs) in the Galactic center (GC). Our sample of 107 YSO candidates was selected based on Infrared Array Camera (IRAC) colors from the high spatial resolution, high sensitivity Spitzer/IRAC images in the Central Molecular Zone, which spans the central {approx}300 pc region of the Milky Way. We obtained IRS spectra over 5-35 {mu}m using both high- and low-resolution IRS modules. We spectroscopically identify massive YSOs by the presence of a 15.4 {mu}m shoulder on the absorption profile of 15 {mu}m CO{sub 2} ice, suggestive of CO{sub 2} ice mixed with CH{sub 3}OH ice on grains. This 15.4 {mu}m shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We show that nine massive YSOs also reveal molecular gas-phase absorption from CO{sub 2}, C{sub 2}H{sub 2}, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first spectroscopic census of the massive YSO population in the GC. We fit YSO models to the observed spectral energy distributions and find YSO masses of 8-23 M{sub sun}, which generally agree with the masses derived from observed radio continuum emission. We find that about 50% of photometrically identified YSOs are confirmed with our spectroscopic study. This implies a preliminary star formation rate of {approx}0.07 M{sub sun} yr{sup -1} at the GC.

  13. Deep infrared galaxies

    NASA Technical Reports Server (NTRS)

    Ashby, Matthew; Houck, J. R.; Hacking, Perry B.

    1992-01-01

    High signal-to-noise ratio optical spectra of 17 infrared-bright emission-line galaxies near the north ecliptic pole are presented. Reddening-corrected line ratios forbidden O III 5007/H-beta, N II 6583/H-alpha, S II (6716 + 6731)/H-alpha, and O I 6300/H-alpha are used to discriminate between candidate energy generation mechanisms in each galaxy. These criteria have frequently been applied to optically selected samples of galaxies in the past, but this is the first time they have been applied to a set of faint flux-limited infrared-selected objects. The analysis indicates the sample contains seven starburst galaxies and three (AGN). However, seven galaxies in the present sample elude the classification scheme based on these line ratios. It is concluded that a two-component (starburst plus AGN) model for energy generation is inadequate for infrared galaxies.

  14. Young stellar object variability (YSOVAR): Long timescale variations in the mid-infrared

    SciTech Connect

    Rebull, L. M.; Cody, A. M.; Stauffer, J. R.; Morales-Calderón, M.; Carey, S. J.; Covey, K. R.; Günther, H. M.; Poppenhaeger, K.; Wolk, S. J.; Hora, J. L.; Hillenbrand, L. A.; Plavchan, P.; Gutermuth, R.; Song, I.; Barrado, D.; Bayo, A.; James, D.; Vrba, F. J.; Alves de Oliveira, C.; Bouvier, J.; and others

    2014-11-01

    The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (3.6 and 4.5 μm) time series photometry of the Orion Nebula Cluster plus smaller footprints in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ∼29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. We present the data collection and reduction for the Spitzer and ancillary data, and define the 'standard sample' on which we calculate statistics, consisting of fast cadence data, with epochs roughly twice per day for ∼40 days. We also define a 'standard sample of members' consisting of all the IR-selected members and X-ray-selected members. We characterize the standard sample in terms of other properties, such as spectral energy distribution shape. We use three mechanisms to identify variables in the fast cadence data—the Stetson index, a χ{sup 2} fit to a flat light curve, and significant periodicity. We also identified variables on the longest timescales possible of six to seven years by comparing measurements taken early in the Spitzer mission with the mean from our YSOVAR campaign. The fraction of members in each cluster that are variable on these longest timescales is a function of the ratio of Class I/total members in each cluster, such that clusters with a higher fraction of Class I objects also have a higher fraction of long-term variables. For objects with a YSOVAR-determined period and a [3.6]-[8] color, we find that a star with a longer period is more likely than those with shorter periods to have an IR excess. We do not find any evidence for variability that causes [3.6]-[4.5] excesses to appear or vanish within our data set; out of members and field objects combined, at most 0.02% may have transient IR excesses.

  15. Infrared Astronomical Satellite /IRAS/ and Shuttle Infrared Telescope Facility /SIRTF/ - Implications of scientific objectives on focal plane sensitivity requirements

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Walker, R. G.; Witteborn, F. C.

    1978-01-01

    The full potential of infrared astronomy can be realized only through observations made with space-based telescopes cooled to cryogenic temperatures. The paper outlines the scientific mission, system description, and focal plane requirements for two cryogenic telescopes: the Infrared Astronomical Satellite (IRAS) and the Shuttle Infrared Telescope Facility (SIRTF). IRAS, a 60-cm superfluid-helium-cooled telescope system, will perform a one-year 8-120-micron IR sky survey; it will provide results of high reliability and sensitivity, produce the first complete survey data for the 30-120-micron region, and fill in missing portions (spectrally and spatially) of previous surveys short of 30 microns; its focal plane assembly is being designed to approach background-limited performance with an array of 62 discrete detectors. The SIRTF design will allow detailed follow-up studies in the 1-1000-micron range with a 116-160-cm observatory-class instrument. The Shuttle sortie capability introduces the unique SIRTF concept of an easily refurbishable or replaceable focal plane instrument complement in an orbiting cryogenic telescope.

  16. WIDE-FIELD INFRARED SURVEY EXPLORER OBSERVATIONS OF YOUNG STELLAR OBJECTS IN THE WESTERN CIRCINUS MOLECULAR CLOUD

    SciTech Connect

    Liu, Wilson M.; Fajardo-Acosta, Sergio; Padgett, Deborah L.; Leisawitz, David; Koenig, Xavier P.

    2011-05-20

    The Wide-field Infrared Survey Explorer has uncovered a population of young stellar objects (YSOs) in the Western Circinus molecular cloud. Images show the YSOs to be clustered into two main groups that are coincident with dark filamentary structure in the nebulosity. Analysis of photometry shows numerous Class I and II objects. The locations of several of these objects are found to correspond to known dense cores and CO outflows. Class I objects tend to be concentrated in dense aggregates, and Class II objects more evenly distributed throughout the region.

  17. Subaru Near-Infrared Multicolor Images of Class II Young Stellar Object, RNO 91

    NASA Astrophysics Data System (ADS)

    Mayama, Satoshi; Tamura, Motohide; Hayashi, Masahiko; Itoh, Yoichi; Ishii, Miki; Fukagawa, Misato; Hayashi, Saeko S.; Oasa, Yumiko; Kudo, Tomoyuki

    2007-12-01

    We conducted subarcsecond near-infrared imaging observations of RNO 91 with CIAO (Coronagraphic Imager with Adaptive Optics) mounted on the 8.2m Subaru telescope. We present our JHK band data along with optical images, which when considered together reveal a complex circumstellar structure. We examined the colors of associated nebulae and compared the geometry of the outflow/disk system suggested by our data with that already proposed on the basis of previous studies. Our K-band image shows bright circumstellar nebulosity detected within ˜ 2" around the central source, while it is less conspicuous at shorter wavelengths. PA and the size of this red color nebulosity agree with those of the previously detected polarization disk. Agreements among these data indicate that this bright nebulosity region, which follows the reddening law, might be attributed to a disklike structure. At J and optical wavelengths, several blue knotlike structures are detected around and beyond the bright circumstellar nebulosity. We suggest that these knotty reflection nebulae may represent disintegrating fragments of an infalling envelope. The three-color composite image has the appearance of arc-shaped nebulosity. We interpret these structures as being roots of a bipolar cavity opening toward the northeast and the southwest. The complex distribution of reflection nebulosity seen around RNO 91 appears to confirm the interpretation that this source is an object dispersing its molecular envelope while transitioning from protostar to T Tauri star.

  18. Spectrum from Faint Galaxy IRAS F00183-7111

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's Spitzer Space Telescope has detected the building blocks of life in the distant universe, albeit in a violent milieu. Training its powerful infrared eye on a faint object located at a distance of 3.2 billion light-years, Spitzer has observed the presence of water and organic molecules in the galaxy IRAS F00183-7111. With an active galactic nucleus, this is one of the most luminous galaxies in the universe, rivaling the energy output of a quasar. Because it is heavily obscured by dust (see visible-light image in the inset), most of its luminosity is radiated at infrared wavelengths.

    The infrared spectrograph instrument onboard Spitzer breaks light into its constituent colors, much as a prism does for visible light. The image shows a low-resolution spectrum of the galaxy obtained by the spectrograph at wavelengths between 4 and 20 microns. Spectra are graphical representations of a celestial object's unique blend of light. Characteristic patterns, or fingerprints, within the spectra allow astronomers to identify the object's chemical composition and to determine such physical properties as temperature and density.

    The broad depression in the center of the spectrum denotes the presence of silicates (chemically similar to beach sand) in the galaxy. An emission peak within the bottom of the trough is the chemical signature for molecular hydrogen. The hydrocarbons (orange) are organic molecules comprised of carbon and hydrogen, two of the most common elements on Earth. Since it has taken more than three billion years for the light from the galaxy to reach Earth, it is intriguing to note the presence of organics in a distant galaxy at a time when life is thought to have started forming on our home planet.

    Additional features in the spectrum reveal the presence of water ice (blue), carbon dioxide ice (green) and carbon monoxide (purple) in both gas and solid forms. The magenta peak corresponds to singly ionized neon gas, a spectral line often used by

  19. MOSFIRE, the multi-object spectrometer for infra-red exploration at the Keck Observatory

    NASA Astrophysics Data System (ADS)

    McLean, Ian S.; Steidel, Charles C.; Epps, Harland W.; Konidaris, Nicholas; Matthews, Keith Y.; Adkins, Sean; Aliado, Theodore; Brims, George; Canfield, John M.; Cromer, John L.; Fucik, Jason; Kulas, Kristin; Mace, Greg; Magnone, Ken; Rodriguez, Hector; Rudie, Gwen; Trainor, Ryan; Wang, Eric; Weber, Bob; Weiss, Jason

    2012-09-01

    This paper describes the as-built performance of MOSFIRE, the multi-object spectrometer and imager for the Cassegrain focus of the 10-m Keck 1 telescope. MOSFIRE provides near-infrared (0.97 to 2.41 μm) multi-object spectroscopy over a 6.1' x 6.1' field of view with a resolving power of R~3,500 for a 0.7" (0.508 mm) slit (2.9 pixels in the dispersion direction), or imaging over a field of view of ~6.9' diameter with ~0.18" per pixel sampling. A single diffraction grating can be set at two fixed angles, and order-sorting filters provide spectra that cover the K, H, J or Y bands by selecting 3rd, 4th, 5th or 6th order respectively. A folding flat following the field lens is equipped with piezo transducers to provide tip/tilt control for flexure compensation at the <0.1 pixel level. Instead of fabricated focal plane masks requiring frequent cryo-cycling of the instrument, MOSFIRE is equipped with a cryogenic Configurable Slit Unit (CSU) developed in collaboration with the Swiss Center for Electronics and Microtechnology (CSEM). Under remote control the CSU can form masks containing up to 46 slits with ~0.007-0.014" precision. Reconfiguration time is < 6 minutes. Slits are formed by moving opposable bars from both sides of the focal plane. An individual slit has a length of 7.0" but bar positions can be aligned to make longer slits in increments of 7.5". When masking bars are retracted from the field of view and the grating is changed to a mirror, MOSFIRE becomes a wide-field imager. The detector is a 2K x 2K H2-RG HgCdTe array from Teledyne Imaging Sensors with low dark current and low noise. Results from integration and commissioning are presented.

  20. Ambient and Cryogenic Alignment Verification and Performance of the Infrared Multi-Object Spectrometer

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mink, Ronald G.; Mentzell, J. Eric; Saha, Timo T.; Tveekrem, June L.; Hylan, Jason E.; Sparr, Leroy M.; Chambers, V. John; Hagopian, John G.

    2003-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a facility instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low- to mid-resolving power (R = 300 - 3000). IRMOS produces simultaneous spectra of approximately 100 objects in its 2.8 x 2.0 arc-min field of view using a commercial Micro Electro-Mechanical Systems (MEMS) Digital Micro-mirror Device (DMD) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the DMD field stop, and the spectrograph images the DMD onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and the ambient and cryogenic imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve to venfy alignment, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides further verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides spectral lines at 546.1 nm and 1550 nm, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard test results validate this prediction. We conclude with an instrument performance prediction for first light.

  1. Imaging performance and modeling of the Infrared Multi-Object Spectrometer focal reducer

    NASA Astrophysics Data System (ADS)

    Connelly, Joseph A.; Ohl, Raymond G., IV; Saha, Timo T.; Hadjimichael, Theo; Mentzell, John E.; Mink, Ronald G.; Hylan, Jason E.; Sparr, Leroy M.; Chambers, John; Hagopian, John J.; Greenhouse, Matthew A.; Winsor, Robert S.; MacKenty, John W.

    2003-03-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a facility instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8 2.5 μm) spectrometer with low- to mid-resolving power (R = 300 3000). The IRMOS spectrometer produces simultaneous spectra of ~100 objects in its 2.8 x 2.0 arcmin field of view using a commercial MEMS multi-mirror array device (MMA) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the MMA field stop, and the spectrograph images the MMA onto the detector. We describe the breadboard subsystem alignment method and imaging performance of the focal reducer. This testing provides verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Interferometric measurements of subsystem wavefront error serve to verify alignment and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing is then performed for the central field point. A mercury-argon pencil lamp provides the spectral line at 546.1 nm, and a CCD camera is the detector. We use the Optical Surface Analysis Code to predict the point-spread function and its effect on instrument slit transmission, and our breadboard test results validate this prediction. Our results show that scattered light from the subsystem and encircled energy is slightly worse than expected. Finally, we perform component level image testing of the MMA, and our results show that scattered light from the MMA is of the same magnitude as that of the focal reducer.

  2. Subsystem Imaging Performance and Modeling of the Infrared Multi-Object Spectrograph

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Tveekrem, June L.; Ohl, Raymond G.; Mink, Ronald; Chambers, V. John; Mentzell, J. Eric; Greenhouse, Matthew A.; MacKenty, John W.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Infrared Multi-Object Spectrograph (IRMOS) is a facility instrument for the Kitt Peak National Observatory Mayall Telescope (3.8 meter). IRMOS is a near-IR (0.8 - 2.5 micron) spectrograph with low to mid resolution (R=lambda/delta, lambda = 300 - 3800). The IRMOS spectrograph produces simultaneous spectra of - 100 objects in its 2.8 x 2.0 arc-min field of view using a commercial MEMS multi-mirror array device (MMA). The IRMOS optical design consists of two imaging systems, or "stages." The focal reducer, stage one, images the focal plane of the telescope onto the MMA. The spectrograph, stage two, images the MMA onto the detector. We describe the breadboard alignment method and imaging and scattered light performance for both the focal reducer and spectrograph. This testing provides verification of the optomechanical alignment method, and a measurement of the contribution of scattered light in the system due to mirror small scale surface error. After the stage I and 2 optics are integrated with the instrument, our test results will make it possible to distinguish between scattered light from the mirrors and the MMA. Image testing will be done at four wavelengths in the visible and near-IR. A mercury-argon pencil lamp will provide spectral lines at 546.1 and 1012 nm, and a blackbody radiation source lines at 1600 and 2200 nm. A CCD camera will be used as a detector for the visible wavelengths, and an IR photodiode will be used for the IR wavelengths. We compare our data with a theoretical analysis using a commercial software package. Mirror surface error is modeled by treating each surface as a superposition of various gratings (e.g., diamond turning tool marks, features due to the impurities of Al 6061, and periodic mid-frequency errors due to drift during machining).

  3. Faint Submillimeter Galaxies Behind the Frontier Field Clusters

    NASA Astrophysics Data System (ADS)

    Hsu, Li-Yen; Cowie, Lennox; Barger, Amy; Wang, Wei-Hao; Chen, Chian-Chou

    2015-08-01

    Faint submillimeter galaxies are the major contributors to the submillimeter extragalactic background light and hence the dominant star-forming population in the dusty universe. Determining how much these galaxies overlap the optically selected samples is critical to fully account for the cosmic star formation history. To explore this faint submillimeter population, we have been observing nine galaxy clusters with the SCUBA-2 camera on the James Clerk Maxwell Telescope, including five of the clusters in the HST Frontier Fields program. We have also been using the Submillimeter Array to determine the positions of our detected sources precisely. Our recent observations have discovered several high-redshift dusty galaxies with far-infrared luminosities similar to that of the Milky Way or luminous infrared galaxies but which are undetected in current deep radio, optical and near-infrared images. These remarkable results suggest that a substantial amount of star formation in even the faint submillimeter population may be hidden from rest-frame optical surveys.

  4. MID-INFRARED SIZE SURVEY OF YOUNG STELLAR OBJECTS: DESCRIPTION OF KECK SEGMENT-TILTING EXPERIMENT AND BASIC RESULTS

    SciTech Connect

    Monnier, J. D.; Tannirkulam, A.; Tuthill, P. G.; Ireland, M.; Cohen, R.; Perrin, M. D.

    2009-07-20

    The mid-infrared properties of pre-planetary disks are sensitive to the temperature and flaring profiles of disks for the regions where planet formation is expected to occur. In order to constrain theories of planet formation, we have carried out a mid-infrared ({lambda} = 10.7 {mu}m) size survey of young stellar objects using the segmented Keck telescope in a novel configuration. We introduced a customized pattern of tilts to individual mirror segments to allow efficient sparse-aperture interferometry, allowing full aperture synthesis imaging with higher calibration precision than traditional imaging. In contrast to previous surveys on smaller telescopes and with poorer calibration precision, we find that most objects in our sample are partially resolved. Here, we present the main observational results of our survey of five embedded massive protostars, 25 Herbig Ae/Be stars, 3 T Tauri stars, 1 FU Ori system, and five emission-line objects of uncertain classification. The observed mid-infrared sizes do not obey the size-luminosity relation found at near-infrared wavelengths and a companion paper will provide further modeling analysis of this sample. In addition, we report imaging results for a few of the most resolved objects, including complex emission around embedded massive protostars, the photoevaporating circumbinary disk around MWC 361A, and the subarcsecond binaries T Tau, FU Ori, and MWC 1080.

  5. Near-infrared Spectroscopy of Infrared-excess Stellar Objects in the Young Supernova Remnant G54.1+0.3

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Jeong; Koo, Bon-Chul; Moon, Dae-Sik

    2013-09-01

    We present the results of broadband near-infrared spectroscopic observations of the recently discovered mysterious stellar objects in the young supernova remnant G54.1+0.3. These objects, which show significant mid-infrared-excess emission, are embedded in a diffuse loop structure of ~1' in radius. Their near-infrared spectra reveal characteristics of late O- or early B-type stars with numerous H and He I absorption lines, and we classify their spectral types to be between O9 and B2 based on an empirical relation derived here between the equivalent widths of the H lines and stellar photospheric temperatures. The spectral types, combined with the results of spectral energy distribution fits, constrain the distance to the objects to be 6.0 ± 0.4 kpc. The photometric spectral types of the objects are consistent with those from the spectroscopic analyses, and the extinction distributions indicate a local enhancement of matter in the western part of the loop. If these objects originate via triggered formation by the progenitor star of G54.1+0.3, then their formations likely began during the later evolutionary stages of the progenitor, although a rather earlier formation may still be possible. If the objects and the progenitor belong to the same cluster of stars, then our results constrain the progenitor mass of G54.1+0.3 to be between 18 and ~35 M ⊙ and suggest that G54.1+0.3 was either a Type IIP supernova or, with a relatively lower possibility, Type Ib/c from a binary system.

  6. NEAR-INFRARED SPECTROSCOPY OF INFRARED-EXCESS STELLAR OBJECTS IN THE YOUNG SUPERNOVA REMNANT G54.1+0.3

    SciTech Connect

    Kim, Hyun-Jeong; Koo, Bon-Chul; Moon, Dae-Sik E-mail: koo@astro.snu.ac.kr

    2013-09-01

    We present the results of broadband near-infrared spectroscopic observations of the recently discovered mysterious stellar objects in the young supernova remnant G54.1+0.3. These objects, which show significant mid-infrared-excess emission, are embedded in a diffuse loop structure of {approx}1' in radius. Their near-infrared spectra reveal characteristics of late O- or early B-type stars with numerous H and He I absorption lines, and we classify their spectral types to be between O9 and B2 based on an empirical relation derived here between the equivalent widths of the H lines and stellar photospheric temperatures. The spectral types, combined with the results of spectral energy distribution fits, constrain the distance to the objects to be 6.0 {+-} 0.4 kpc. The photometric spectral types of the objects are consistent with those from the spectroscopic analyses, and the extinction distributions indicate a local enhancement of matter in the western part of the loop. If these objects originate via triggered formation by the progenitor star of G54.1+0.3, then their formations likely began during the later evolutionary stages of the progenitor, although a rather earlier formation may still be possible. If the objects and the progenitor belong to the same cluster of stars, then our results constrain the progenitor mass of G54.1+0.3 to be between 18 and {approx}35 M{sub Sun} and suggest that G54.1+0.3 was either a Type IIP supernova or, with a relatively lower possibility, Type Ib/c from a binary system.

  7. Optical and Near Infrared Study of the Cepheus E Outflow, a Very Low Excitation Object

    NASA Technical Reports Server (NTRS)

    Noreiga-Crespo, A.; Ayala, S.; Garnavich, P.; Curiel, S.; Raga, A.; Bohm, K.; Raymond, J.

    2000-01-01

    In this study, we explore the link between the physical properties of the outflow as determined from optical imaging and spectroscopy, and compare these results with those obtained from observations in the near infrared.

  8. YOUNG STELLAR OBJECT SEARCH TOWARD THE BOUNDARY OF THE CENTRAL MOLECULAR ZONE WITH NEAR-INFRARED POLARIMETRY

    SciTech Connect

    Yoshikawa, Tatsuhito; Nagata, Tetsuya; Nishiyama, Shogo; Kwon, Jungmi; Tamura, Motohide E-mail: nagata@kusastro.kyoto-u.ac.jp

    2014-08-01

    We have carried out near-infrared polarimetry toward the boundary of the Central Molecular Zone, in the field of (–1.°4 ≲ l ≲ –0.°3 and 1.°0 ≲ l ≲ 2.°9, |b| ≲ 0.°1), using the near-infrared polarimetric camera SIRPOL on the 1.4 m Infrared Survey Facility telescope. We have selected 112 intrinsically polarized sources on the basis of the estimate of interstellar polarization on Stokes Q/I – U/I planes. The selected sources are brighter than K{sub S} = 14.5 mag and have polarimetric uncertainty δP < 1%. Ten of these distinctive polarized sources are fit well with spectral energy distributions of young stellar objects when using the photometry in the archive of the Spitzer Space Telescope mid-infrared data. However, many sources have spectral energy distributions of normal stars suffering from heavy interstellar extinction; these might be stars behind dark clouds. Due to the small number of distinctive polarized sources and candidates of young stellar objects, we cannot judge if they are declining in number outside the Central Molecular Zone. Many massive candidates for young stellar objects in the literature have only small intrinsic polarization. This might suggest that their masses are 4-15 M {sub ☉}, whose intrinsic polarization has been expected to be small.

  9. Development of an integral field unit for a near-infrared multi-object imaging spectrograph SWIMS

    NASA Astrophysics Data System (ADS)

    Ozaki, Shinobu; Kitagawa, Yutaro; Motohara, Kentaro; Konishi, Masahiro; Takahashi, Hidenori; Yoshikawa, Tomohiro; Tateuchi, Ken; Kato, Natsuko

    2012-09-01

    We are developing an integral field unit (IFU) for a near-infrared multi-object imaging spectrograph SWIMS (Simultaneous-color Wide-field Infrared Multi-object Spectrograph). SWIMS is an instrument for the 6.5m telescope of the University of Tokyo Atacama Observatory (TAO) project on the summit of Co. Chajnantor (altitude of 5,640m) in northern Chile. Most of near infrared integral field spectrographs (IFSs) on 8-10m class telescopes are used with adaptive optics and have fine spatial sampling. Compared with them, SWIMS IFU has higher sensitivity for extended objects because it has coarser spatial sampling optimized for seeing-limit observations. We have investigated the feasible optical design, and found a possible layout whose field of view is about 14 x 10 arcsec2 with 0.4 arcsec slice width. All IFU mirror arrays will be made of aluminum alloy to match the thermal expansion with support structures, as they are placed in a cryogenic environment. They will be fabricated monolithically with high precision machining to reduce alignment process. We have carried out a fabrication test of a spherical surface and confirmed that surface roughness and surface figure error are enough low for near-infrared light. As a next step, fabrication of a prototype mirror array with 3 reflective surfaces is planned. In this paper, we will show our project outline, the IFU optical design and the results of prototyping works.

  10. Near-Infrared Rotational Variability in Comet-Asteroid Transition Object 944 Hidalgo

    NASA Astrophysics Data System (ADS)

    Campins, Humberto; Licandro, J.; Fernandez, Y.; Hergenrother, C.; Ziffer, J.; Emery, J.; Cruikshank, D.; Pinilla-Alonso, N.

    2006-09-01

    Dynamical arguments indicate that 944 Hidalgo is most likely an extinct or dormant comet. Hidalgo's Tisserand invariant (T = 2.07) suggests strongly that this object came either from the Kuiper belt or the Oort cloud (e.g., Weissman et al. 2002). We obtained low-resolution near-infrared spectra in the 0.8-2.4 micron region on UT Oct 22, 23, Nov 19 and Dec 11, 2004, using the SpeX instrument on NASA's Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii (Oct. and Nov.) and the NICS instrument on the Telescopio Nazionale Galileo (TNG) on La Palma, Spain (Dec.). Our reflectance spectra show a range of slopes. To characterize these slope differences, we normalized each spectrum to 1.0 reflectance at 1.25 microns and measured the reflectance at 2.2 microns. These values are listed in the table for the seven spectra obtained on the two dates when we have temporal coverage, Oct 22 and 23. The uncertainty in each reflectance value is ± 3%. Hidalgo's rotational light curve has a period of 10.06 hours and amplitudes ranging from 0.31 to 0.6 magnitudes in the visible (Harris and Warner 2006, Minor Planet Center). We define the time of our first observation on Oct. 22 as zero rotational phase and give the other six phases in the table. The table shows a systematic temporal variation of the spectral slope consistent with the rotational period. Based on an unpublished visible light curve obtained 10 days earlier (C. Hergenrother personal communication) we determine that one of the small ends of Hidalgo corresponds to our "reddest” spectrum (phase 0.36) while one of the broad sides has the flattest spectrum (phase 0.77).

    Reflectance at 2.2 μm1.261.311.391.36a Faint and Lonely Brown Dwarf in the Solar Vicinity

    NASA Astrophysics Data System (ADS)

    1997-04-01

    La Silla, each covering a sky area of 5 o.5 x 5 o.5. When comparing plates of the same sky field obtained at time intervals of several years [1] , she was able to detect, among the hundreds of thousands of stellar images on the plates, a few faint ones whose positions had changed a little in the meantime. The search technique is based on the fact that such a shift is a good indicator of the object being relatively nearby. It must therefore also be intrinsically faint, i.e. a potential White Dwarf candidate. On every pair of plates, approximately twenty faint moving objects were detected with proper motions [2] of more than 0.25 arcsec per year. Indeed, follow-up spectroscopic observations showed that about 20 percent of these or about four per plate were White Dwarfs. Until now, a total of forty new White Dwarfs have been discovered during this very successful project, i.e. over ten times more than originally expected. And then - a Brown Dwarf! Caption to ESO PR Photo 11/97 [JPEG, 144k] ESO Press Photo 11/97 When checking two plates with a time inverval of 11 years, Maria Teresa Ruiz earlier this year discovered a very faint object in the southern constellation of Hydra (The Water-Snake), moving at 0.35 arcsec per year (cf. ESO Press Photo 11/97). In order to establish its true nature, she obtained its spectrum (in the visual to near-infrared region from wavelengths 450-1000 nm) on March 15 using the ESO 3.6-m telescope and the EFOSC1 spectrograph. Caption to ESO PR Photo 12/97 [GIF, 35k] ESO Press Photo 12/97 To her great surprise, the spectrum was of a type never seen before and certainly not that of a White Dwarf or any other easily identifiable type of star (cf. ESO Press Photo 12/97). In particular, there were no signs of spectral bands of titanium oxide (TiO) or vanadium oxide (VO) which are common in very cool stars, nor of the spectral lines seen in White Dwarfs. On the other hand, an absorption line of the short-lived element lithium was identified, as well

  11. A Search For Optically Faint GEO Debris

    NASA Astrophysics Data System (ADS)

    Seitzer, P.; Lederer, S.; Barker, E.; Cowardin, H.; Abercromby, K.; Silha, J.; Burkhardt, A.

    2011-09-01

    Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan telescope ‘Walter Baade’ at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe preliminary results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r’ filter. The limiting magnitude for 5 second exposures is measured to be fainter tan R = 21. With this small field of view and the limited observing time, our objective was to search for optically faint objects from the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris (SSN # 25001 and 33519) with the 6.5-m telescope, followed by a survey for objects on similar orbits but with a spread in mean anomaly. To detect bright objects over a wider field of view (1.6x1.6 degrees), we observed the same field centers at the same time through a similar filter with the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will describe our experiences using Magellan, a telescope never used previously for orbital debris research, and our initial results.

  12. A Search for Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Lederer, Susan M.; Barker, Edwin S.; Cowardin, Heather; Abercromby, Kira J.; ilha, Jiri

    2011-01-01

    Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan 1 telescope Walter Baade at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r filter. The limiting magnitude for 5 second exposures is estimated to be fainter than 22. With this small field of view and the limited observing time, our objective was to search for optically faint objects from the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris (SSN # 25001 and 33519) with the 6.5-m telescope, followed by a survey for objects on similar orbits but with a spread in mean anomaly. To detect bright objects over a wider field of view (1.6x1.6 degrees), we observed the same field centers at the same time through a similar filter with the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will describe our experiences using Magellan, a telescope never used previously for orbital debris research, and our initial results.

  13. Fainting

    MedlinePlus

    ... kids: drink plenty of fluids, especially in hot weather or during physical activity take frequent breaks and move around as much as possible when sitting or standing for long periods of time slowly breathe into a paper bag ... Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart. ...

  14. Faintness

    MedlinePlus

    ... decisions about when and where they should receive healthcare. Unfortunately, most people lack the medical knowledge needed to make these decisions safely. FreeMD.com is powered by a computer program that performs symptom triage. The goal of ...

  15. Fainting

    MedlinePlus

    ... severely dehydrated ) Standing up very suddenly from a lying position Less common but more serious reasons for ... avoid or change them. Get up from a lying or seated position slowly. If having blood drawn ...

  16. Detection of buried objects by fusing dual-band infrared images

    SciTech Connect

    Clark, G.A.; Sengupta, S.K.; Sherwood, R.J.; Buhl, M.R.; Schaich, P.C.; Kane, R.J.; Barth, M.J.; Fields, D.J.; Carter, M.R.

    1993-11-01

    We have conducted experiments to demonstrate the enhanced detectability of buried land mines using sensor fusion techniques. Multiple sensors, including visible imagery, infrared imagery, and ground penetrating radar (GPR), have been used to acquire data on a number of buried mines and mine surrogates. Because the visible wavelength and GPR data are currently incomplete. This paper focuses on the fusion of two-band infrared images. We use feature-level fusion and supervised learning with the probabilistic neural network (PNN) to evaluate detection performance. The novelty of the work lies in the application of advanced target recognition algorithms, the fusion of dual-band infrared images and evaluation of the techniques using two real data sets.

  17. Recursive estimation techniques for detection of small objects in infrared image data

    NASA Astrophysics Data System (ADS)

    Zeidler, J. R.; Soni, T.; Ku, W. H.

    1992-04-01

    This paper describes a recursive detection scheme for point targets in infrared (IR) images. Estimation of the background noise is done using a weighted autocorrelation matrix update method and the detection statistic is calculated using a recursive technique. A weighting factor allows the algorithm to have finite memory and deal with nonstationary noise characteristics. The detection statistic is created by using a matched filter for colored noise, using the estimated noise autocorrelation matrix. The relationship between the weighting factor, the nonstationarity of the noise and the probability of detection is described. Some results on one- and two-dimensional infrared images are presented.

  18. A near-infrared spectroscopic survey of massive jets towards extended green objects

    NASA Astrophysics Data System (ADS)

    Caratti o Garatti, A.; Stecklum, B.; Linz, H.; Garcia Lopez, R.; Sanna, A.

    2015-01-01

    Context. Protostellar jets and outflows are the main outcome of the star formation process, and their analysis can provide us with major clues about the ejection and accretion history of young stellar objects (YSOs). Aims: We aim at deriving the main physical properties of massive jets from near-infrared (NIR) observations, comparing them to those of a large sample of jets from low-mass YSOs, and relating them to the main features of their driving sources. Methods: We present a NIR imaging (H2 and Ks) and low-resolution spectroscopic (0.95-2.50 μm) survey of 18 massive jets towards GLIMPSE extended green objects (EGOs), driven by intermediate- and high-mass YSOs, which have bolometric luminosities (Lbol) between 4 × 102 and 1.3 × 105 L⊙. Results: As in low-mass jets, H2 is the primary NIR coolant, detected in all the analysed flows, whereas the most important ionic tracer is [Fe ii], detected in half of the sampled jets. Our analysis indicates that the emission lines originate from shocks at high temperatures and densities. No fluorescent emission is detected along the flows, regardless of the source bolometric luminosity. On average, the physical parameters of these massive jets (i.e. visual extinction, temperature, column density, mass, and luminosity) have higher values than those measured in their low-mass counterparts. The morphology of the H2 flows is varied, mostly depending on the complex, dynamic, and inhomogeneous environment in which these massive jets form and propagate. All flows and jets in our sample are collimated, showing large precession angles. Additionally, the presence of both knots and jets suggests that the ejection process is continuous with burst episodes, as in low-mass YSOs. We compare the flow H2 luminosity with the source bolometric luminosity confirming the tight correlation between these two quantities. Five sources, however, display a lower LH2/Lbol efficiency, which might be related to YSO evolution. Most important, the

  19. Searching for Optically Faint GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Lederer, Susan M.; Abercromby, Kira J.; Barker, Edwin S.; Burkhardt, Andrew; Cowardin, Heather; Krisko, Paula; Silha, Jiri

    2012-01-01

    We report on results from a search for optically faint debris (defined as R > 20th magnitude, or smaller than 10 cm assuming an albedo of 0.175)) at geosynchronous orbit (GEO) using the 6.5-m Magellan telescope "Walter Baade" at Las Campanas Observatory in Chile. Our goal is to characterize the brightness distribution of debris to the faintest limiting magnitude possible. Our data was obtained during 6 hours of observing time during the photometric nights of 26 and 27 March 2011 with the IMACS f/2 instrument, which has a field of view (fov) of 0.5 degrees in diameter. All observations were obtained through a Sloan r filter, and calibrated by observations of Landolt standard stars. Our primary objective was to search for optically faint objects from one of the few known fragmentations at GEO: the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris with the 6.5-m telescope, followed by a survey for unknown objects on similar orbits but with different mean anomalies. To establish the bright end of the debris population, calibrated observations were acquired on the same field centers, telescope rates, and time period with a similar filter on the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will show the calibrated brightness distributions from both telescopes, and compare the observed brightness distributions with that predicted for various population models of debris of different sizes.

    1. Wide-field infrared survey explorer observations of young stellar objects in the Lynds 1509 dark cloud in Auriga

      SciTech Connect

      Liu, Wilson M.; McCollum, Bruce; Fajardo-Acosta, Sergio; Padgett, Deborah L.; Terebey, Susan; Angione, John; Rebull, Luisa M.; Leisawitz, David

      2014-06-01

      The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 μm, 4.6 μm, 12 μm, and 22 μm, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

    2. Wide-Field Infrared Survey Explorer Observations of Young Stellar Objects in the Lynds 1509 Dark Cloud in Auriga

      NASA Technical Reports Server (NTRS)

      Liu, Wilson M.; Padgett, Deborah L.; Terebey, Susan; Angione, John; Rebull, Luisa M.; McCollum, Bruce; Fajardo-Acosta, Sergio; Leisawitz, David

      2015-01-01

      The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4, 4.6, 12, and 22 microns, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc.

    3. Investigation of Variability of Faint Galactic Early-Type Carbon Stars from the First Byurakan Spectral Sky Survey

      NASA Astrophysics Data System (ADS)

      Gigoyan, K. S.; Kostandyan, G. R.; Paronyan, G. M.

      2016-06-01

      In this poster, we discuss the nature of 66 faint carbon (C) stars which have been discovered by scrutinizing the plates of the First Byurakan Survey (FBS). These plates display low-resolution spectra of objects located at high Galactic latitudes and have a limiting magnitude of about V=16. Our sample of 66 confirmed spectroscopically to be C stars. These 66 objects are those which show early-type spectra. To better characterize these objects, medium-resolution CCD spectra were obtained and are exploited for them all, together with consideration of their 2MASS near-infrared (NIR) colors and their optical variability. We derive effective temperatures from photometry. Finally, the optical variability of our objects are studied by using the data of the Catalina Sky Survey (CSS). It is found that the vast majority does not display variability. However, for some of them, the phased light curve may indicate the presence of a secondary component.

    4. Near infrared photographic sky survey. 1: Catalog of red stellar objects

      NASA Technical Reports Server (NTRS)

      Craine, E. R.; Duerr, R. E.; Horner, V. M.; Imhoff, C. L.; Routsis, D. E.; Swihart, D. L.; Turnshek, D. A.

      1979-01-01

      Red stellar objects for which V-1 was greater than a value of about 2 (supm). 5 were extracted from photographs of 23 program fields. Tabular data for each field show the object name; the 1950 epoch right ascension, declination, galactic longitude, galactic latitude; radial distance from field venter in decimal degrees; color classes; and objects ordered by redness.

    5. Spectral Indices of Faint Radio Sources

      NASA Astrophysics Data System (ADS)

      Gim, Hansung B.; Hales, Christopher A.; Momjian, Emmanuel; Yun, Min Su

      2015-01-01

      The significant improvement in bandwidth and the resultant sensitivity offered by the Karl G. Jansky Very Large Array (VLA) allows us to explore the faint radio source population. Through the study of the radio continuum we can explore the spectral indices of these radio sources. Robust radio spectral indices are needed for accurate k-corrections, for example in the study of the radio - far-infrared (FIR) correlation. We present an analysis of measuring spectral indices using two different approaches. In the first, we use the standard wideband imaging algorithm in the data reduction package CASA. In the second, we use a traditional approach of imaging narrower bandwidths to derive the spectral indices. For these, we simulated data to match the observing parameter space of the CHILES Con Pol survey (Hales et al. 2014). We investigate the accuracy and precision of spectral index measurements as a function of signal-to noise, and explore the requirements to reliably probe possible evolution of the radio-FIR correlation in CHILES Con Pol.

    6. High-sensitivity, and cost-effective system for infrared imaging of concealed objects in dynamic mode.

      SciTech Connect

      Gordiyenko, E.; Yefremenko, V.; Pearson, J.; Bader, S.; Novosad, V.; Materials Science Division

      2005-08-05

      Novel, cost-efficient, and highly-sensitive IR imaging systems play an important role in homeland security functions. Technical limitations in the areas of sensitivity, contrast ratio, bandwidth and cost continue to constrain imaging capabilities. We have designed and prototyped a compact computer-piloted high sensitivity infrared imaging system. The device consists of infrared optics, cryostat, low-noise pre-amplifier, Analog-to-Digital hardware, feedback electronics, and unique image processing software. Important advantages of the developed system are: (i) Eight electronic channels are available for simultaneous registration of IR and visible images in multiple spectral ranges, (ii) Capability of real-time analysis such as comparing the 'sensed' image with 'reference' images from a database, (iii) High accuracy temperature measurement of multiple points on the image by referencing the radiation intensity from the object to a black body model, (iv) Image generation by real-time integration of images from multiple sensors operating from the visible to the terahertz range. The device was tested with a liquid-nitrogen-cooled, single-pixel HgCdTe detector for imaging in 8-12 microns range. The demonstrated examples of infrared imaging of concealed objects in static and dynamic modes include a hammer (metal head and wooden handle), plastic imitator of handguns hidden under clothes, powder in an envelope, and revealing complex wall structures under decorative plaster.

    7. The ISO-IRAS Faint Galaxy Survey

      NASA Technical Reports Server (NTRS)

      Smith, Harding E.

      1999-01-01

      As part of the ISO-IRAS Faint Galaxy Survey ISO Satellite observations of over 600 IRAS sources have been obtained with the ISOCAM instrument. Because our survey strategy involved relatively short integrations, great care was required in developing analysis software including cosmic-ray and transient removal and calibration. These observations have now been through final pipeline processing at IPAC and ground-based follow-up is ongoing. The observations are for sources from two samples: a " Filler' sample selected to be at z greater than 0.1 and a fainter sample which selected for the highest redshift galaxies in the IRAS survey, with redshifts 0.2 less than z less than 1.0. I now have obtained ground-based follow-up spectrophotometry at Lick and Palomar observatories for 100 LFIRGs with 0.1 less than z less than 0.7. Our observations have confirmed that these systems are comparable to nearby LFIRGs such as Arp 220, with L (sub -)(fir) greater than 10(exp 11) L(sub -) sun and typically HII/Liner optical excitation. About 10% of the galaxies show true AGN (Sy2) excitation. Based on our work on a nearby complete sample of LFIRGS, we believe that the majority of these systems are luminous Starbursts, thus this project is tracing the luminous end of the galaxy star-forming luminosity function - the (infrared) star-formation history of the Universe to z approx. 1, a topic of some considerable recent interest. A by-product of these ISOCAM observations is approximately 1 square degree of deep 2 microns pointings outside the IRAS error boxes, allowing us an independent estimate of the mid-infrared log N - log S relation. Ground-based observations of this sample are continuing.

    8. Object detection utilizing a linear retrieval algorithm for thermal infrared imagery

      SciTech Connect

      Ramsey, M.S.

      1996-11-01

      Thermal infrared (TIR) spectroscopy and remote sensing have been proven to be extremely valuable tools for mineralogic discrimination. One technique for sub-pixel detection and data reduction, known as a spectral retrieval or unmixing algorithm, will prove useful in the analysis of data from scheduled TIR orbital instruments. This study represents the first quantitative attempt to identify the limits of the model, specifically concentrating on the TIR. The algorithm was written and applied to laboratory data, testing the effects of particle size, noise, and multiple endmembers, then adapted to operate on airborne Thermal Infrared Multispectral Scanner data of the Kelso Dunes, CA, Meteor Crater, AZ, and Medicine Lake Volcano, CA. Results indicate that linear spectral unmixmg can produce accurate endmember detection to within an average of 5%. In addition, the effects of vitrification and textural variations were modeled. The ability to predict mineral or rock abundances becomes extremely useful in tracking sediment transport, decertification, and potential hazard assessment in remote volcanic regions. 26 refs., 3 figs.

    9. Small object detection in forward-looking infrared images with sea clutter using context-driven Bayesian saliency model

      NASA Astrophysics Data System (ADS)

      Yu, Jin-Gang; Xia, Gui-Song; Deng, Jianjin; Tian, Jinwen

      2015-11-01

      There are two common challenges for small object detection in forward-looking infrared (FLIR) images with sea clutter, namely, detection ambiguity and scale variance. This paper presents a context-driven Bayesian saliency model to deal with these two issues. By inspecting the camera geometry of the FLIR imaging under the background of sea and sky, we observed that there exists dependency relationship between the locations and scales at which objects may occur, and the context which is defined to be the location of horizon line. Based on this observation, we propose to incorporate contextual information into the basic bottom-up saliency computation, and a unified Bayesian model is developed to achieve this goal. The proposed model is generic and can be potentially applied to other circumstances where context is available for facilitating object detection. Experimental results have demonstrated the effectiveness of our method.

    10. Responses of infrared-sensitive tectal units of the pit viper Crotalus atrox to moving objects.

      PubMed

      Kaldenbach, Felix; Bleckmann, Horst; Kohl, Tobias

      2016-06-01

      Rattlesnakes perceive IR radiation with their pit organs. This enables them to detect and strike towards warm-blooded prey even in the dark. In addition, the IR sense allows rattlesnakes to find places for thermoregulation. Animate objects (e.g., prey) tend to move and thus cause moving IR images across the pit membrane. Even when an object is stationary, scanning head movements of rattlesnakes will result in moving IR images across the pit membrane. We recorded the neuronal activity of IR-sensitive tectal neurons of the rattlesnake Crotalus atrox while stimulating the snakes with an IR source that moved horizontally at various velocities. As long as object velocity was low (angular velocity of ~5°/s) IR-sensitive tectal neurons hardly showed any responses. With increasing object velocity though, neuronal activity reached a maximum at ~50°/s. A further increase in object velocity up to ~120°/s resulted in a slight decrease of neuronal activity. Our results demonstrate the importance of moving stimuli for the snake's IR detection abilities: in contrast to fast moving objects, stationary or slowly moving objects will not be detected when the snake is motionless, but might be detected by scanning head movements. PMID:26906281

    11. Detection of Optically Faint GEO Debris

      NASA Technical Reports Server (NTRS)

      Seitzer, P.; Lederer, S.; Barker, E.; Cowardin, H.; Abercromby, K.; Silha, J.; Burkhardt, A.

      2014-01-01

      There have been extensive optical surveys for debris at geosynchronous orbit (GEO) conducted with meter-class telescopes, such as those conducted with MODEST (the Michigan Orbital DEbris Survey Telescope, a 0.6-m telescope located at Cerro Tololo in Chile), and the European Space Agency's 1.0-m space debris telescope (SDT) in the Canary Islands. These surveys have detection limits in the range of 18th or 19th magnitude, which corresponds to sizes larger than 10 cm assuming an albedo of 0.175. All of these surveys reveal a substantial population of objects fainter than R = 15th magnitude that are not in the public U.S. Satellite Catalog. To detect objects fainter than 20th magnitude (and presumably smaller than 10 cm) in the visible requires a larger telescope and excellent imaging conditions. This combination is available in Chile. NASA's Orbital Debris Program Office has begun collecting orbital debris observations with the 6.5-m (21.3-ft diameter) "Walter Baade" Magellan telescope at Las Campanas Observatory. The goal is to detect objects as faint as possible from a ground-based observatory and begin to understand the brightness distribution of GEO debris fainter than R = 20th magnitude.

    12. The faint end of the galaxy luminosity function

      NASA Technical Reports Server (NTRS)

      Treyer, Marie A.; Silk, Joseph

      1994-01-01

      The evolution of the B- and K-band luminosity functions of galaxies is inferred in a relatively model-independent way from deep spectroscopic and photometric surveys. We confirm earlier evidence by Eales for an increase in the amplitude of the B-band galaxy luminosity function at modest redshift (z less than or approx. 0.2). We find in addition that the slope of the faint end of the luminosity function must systematically steepen and progress toward more luminous galaxies with increasing lookback time, assuming that the galaxy redshift distribution may be smoothly extrapolated 2 mag fainter than observed, as suggested by recent gravitational lensing studies. This evolution is shown to be color-dependent, and we predict the near-infrared color distribution of faint galaxies. The luminosity function of blue (B - K less than or approx. 4) galaxies in the range 0.2 less than or approx. z less than or approx. 1 can be represented by a Schechter function with characteristic light density phi(sup *) L(sup *) comparable to that of present-day late-type galaxies, but with a steeper faint end slope alpha approx. 1.4.

    13. Using near-infrared spectroscopy to assess neural activation during object processing in infants.

      PubMed

      Wilcox, Teresa; Bortfeld, Heather; Woods, Rebecca; Wruck, Eric; Boas, David A

      2005-01-01

      The capacity to represent the world in terms of numerically distinct objects (i.e., object individuation) is a milestone in early cognitive development and forms the foundation for more complex thought and behavior. Over the past 10 to 15 yr, infant researchers have expended a great deal of effort to identify the origins and development of this capacity. In contrast, relatively little is known about the neural mechanisms that underlie the ability to individuate objects, in large part because there are a limited number of noninvasive techniques available to measure brain functioning in human infants. Recent research suggests that near-IR spectroscopy (NIRS), an optical imaging technique that uses relative changes in total hemoglobin concentration and oxygenation as an indicator of neural activation, may be a viable procedure for assessing the relation between object processing and brain function in human infants. We examine the extent to which increased neural activation, as measured by NIRS, could be observed in two neural areas known to be involved in object processing, the primary visual cortex and the inferior temporal cortex, during an object processing task. Infants aged 6.5 months are presented with a visual event in which two featurally distinct objects emerge successively to opposite sides of an occluder and neuroimaging data are collected. As predicted, increased neural activation is observed in both the primary visual and inferior cortex during the visual event, suggesting that these neural areas support object processing in the young infant. The outcome has important implications for research in cognitive development, developmental neuroscience, and optical imaging. PMID:15847576

    14. Infrared

      NASA Astrophysics Data System (ADS)

      Vollmer, M.

      2013-11-01

      'Infrared' is a very wide field in physics and the natural sciences which has evolved enormously in recent decades. It all started in 1800 with Friedrich Wilhelm Herschel's discovery of infrared (IR) radiation within the spectrum of the Sun. Thereafter a few important milestones towards widespread use of IR were the quantitative description of the laws of blackbody radiation by Max Planck in 1900; the application of quantum mechanics to understand the rotational-vibrational spectra of molecules starting in the first half of the 20th century; and the revolution in source and detector technologies due to micro-technological breakthroughs towards the end of the 20th century. This has led to much high-quality and sophisticated equipment in terms of detectors, sources and instruments in the IR spectral range, with a multitude of different applications in science and technology. This special issue tries to focus on a few aspects of the astonishing variety of different disciplines, techniques and applications concerning the general topic of infrared radiation. Part of the content is based upon an interdisciplinary international conference on the topic held in 2012 in Bad Honnef, Germany. It is hoped that the information provided here may be useful for teaching the general topic of electromagnetic radiation in the IR spectral range in advanced university courses for postgraduate students. In the most general terms, the infrared spectral range is defined to extend from wavelengths of 780 nm (upper range of the VIS spectral range) up to wavelengths of 1 mm (lower end of the microwave range). Various definitions of near, middle and far infrared or thermal infrared, and lately terahertz frequencies, are used, which all fall in this range. These special definitions often depend on the scientific field of research. Unfortunately, many of these fields seem to have developed independently from neighbouring disciplines, although they deal with very similar topics in respect of the

    15. HUBBLE'S SEARCH FOR FAINT FIELD STARS IN GALACTIC HALO

      NASA Technical Reports Server (NTRS)

      2002-01-01

      Left A NASA Hubble Space Telescope image of a randomly selected area of sky taken to search for faint red stars that might constitute dark matter in our Milky Way Galaxy. (Dark matter is material of an unknown type that makes up most of the mass of our galaxy). If the dark matter in our Galaxy was made of faint red stars -- as many scientists have previously conjectured -- then about 38 such stars should have been visible in this HST image. The simulated stars (diamond-shaped symbols), based on theoretical calculations, illustrate what scientists would have seen if the dark matter were locked-up in faint red stars. These surprising results rule out dim stars as an explanation for dark matter in our Galaxy. Right The unmodified HST image shows the region is actually so devoid of stars that far more distant background galaxies can easily be seen. The field is in the constellation Eridanus, far outside the plane of our Milky Way Galaxy. This region was chosen to highlight stars in the galactic halo, where dark matter exists, and to avoid the contribution of faint stars in the plane of the Galaxy. Technical Information: The image was constructed from seven exposures totaling almost three hours of searching by HST. The field shown is about 1.5 arc-minutes across. The image was taken in near-infrared light (814 nm) with the Wide Field Planetary Camera 2, on Feb 8, 1994. This observation is part of the HST parallel observing program. Credit: J Bahcall, Institute for Advance Study, Princeton and NASA

    16. Visible and infrared investigations of planet-crossing asteroids and outer solar system objects

      NASA Technical Reports Server (NTRS)

      Tholen, David J.

      1991-01-01

      The project is supporting lightcurve photometry, colorimetry, thermal radiometry, and astrometry of selected asteroids. Targets include the planet-crossing population, particularly Earth approachers, which are believed to be the immediate source of terrestrial meteorites, future spacecraft targets, and those objects in the outer belt, primarily the Hilda and Trojan populations, that are dynamically isolated from the main asteroid belt. Goals include the determination of population statistics for the planet-crossing objects, the characterization of spacecraft targets to assist in encounter planning and subsequent interpretation of the data, a comparison of the collisional evolution of dynamically isolated Hilda and Trojan populations with the main belt, and the determination of the mechanism driving the activity of the distant object 2060 Chiron.

    17. Quantifying the Infrared Spectra of Icy Methanol - A New Investigation for Solar System Objects

      NASA Astrophysics Data System (ADS)

      Hudson, Reggie L.; Tway, Tatiana; Gerakines, Perry

      2015-11-01

      The presence and abundances of organic molecules in extraterrestrial settings, such as on TNOs, can be determined using infrared (IR) spectroscopy, but significant challenges exist. Although reference IR spectra for organics under relevant conditions are vital for such work, for many molecules the data needed either do not exist or exist only in fragmentary form. In this presentation we describe new laboratory results for a three-element molecule, methanol (CH3OH), which has been reported to be present in planetary and interstellar ices. Near- and mid-IR spectra at various ice thicknesses and temperatures are presented, band strengths are calculated, and optical constants are derived. Results are compared to those of earlier workers, the influence of assumptions found in the literature is explored, and possible revisions to the literature are described. Although IR spectra of solid CH3OH has been reported by many low-temperature laboratory-astrochemistry groups over the past 25 - 30 years, our work appears to be the first that aims to determine the densities, refractive indices, and resulting mid-IR band strengths and optical constants of both the amorphous and crystalline phases of methanol. The majority of the laboratory work in this project was done by Tatiana Tway, who was supported by a summer internship through the DREAM2 program, which in turn is supported by a grant from NASA’s SSERVI program.

    18. Functional connectivity in the prefrontal cortex measured by near-infrared spectroscopy during ultrarapid object recognition

      NASA Astrophysics Data System (ADS)

      Medvedev, Andrei V.; Kainerstorfer, Jana M.; Borisov, Sergey V.; Vanmeter, John

      2011-01-01

      Near-infrared spectroscopy (NIRS) is a developing technology for low-cost noninvasive functional brain imaging. With multichannel optical instruments, it becomes possible to measure not only local changes in hemoglobin concentrations but also temporal correlations of those changes in different brain regions which gives an optical analog of functional connectivity traditionally measured by fMRI. We recorded hemodynamic activity during the Go-NoGo task from 11 right-handed subjects with probes placed bilaterally over prefrontal areas. Subjects were detecting animals as targets in natural scenes pressing a mouse button. Data were low-pass filtered <1 Hz and cardiac/respiration/superficial layers artifacts were removed using Independent Component Analysis. Fisher's transformed correlations of poststimulus responses (30 s) were averaged over groups of channels unilaterally in each hemisphere (intrahemispheric connectivity) and the corresponding channels between hemispheres (interhemispheric connectivity). The hemodynamic response showed task-related activation (an increase/decrease in oxygenated/deoxygenated hemoglobin, respectively) greater in the right versus left hemisphere. Intra- and interhemispheric functional connectivity was also significantly stronger during the task compared to baseline. Functional connectivity between the inferior and the middle frontal regions was significantly stronger in the right hemisphere. Our results demonstrate that optical methods can be used to detect transient changes in functional connectivity during rapid cognitive processes.

    19. Scientific objectives and selection of targets for the SMART-1 Infrared Spectrometer (SIR)

      USGS Publications Warehouse

      Basilevsky, A.T.; Keller, H.U.; Nathues, A.; Mall, U.; Hiesinger, H.; Rosiek, M.

      2004-01-01

      The European SMART-1 mission to the Moon, primarily a testbed for innovative technologies, was launched in September 2003 and will reach the Moon in 2005. On board are several scientific instruments, including the point-spectrometer SMART-1 Infrared Spectrometer (SIR). Taking into account the capabilities of the SMART-1 mission and the SIR instrument in particular, as well as the open questions in lunar science, a selection of targets for SIR observations has been compiled. SIR can address at least five topics: (1) Surface/regolith processes; (2) Lunar volcanism; (3) Lunar crust structure; (4) Search for spectral signatures of ices at the lunar poles; and (5) Ground truth and study of geometric effects on the spectral shape. For each topic we will discuss specific observation modes, necessary to achieve our scientific goals. The majority of SIR targets will be observed in the nadir-tracking mode. More than 100 targets, which require off-nadir pointing and off-nadir tracking, are planned. It is expected that results of SIR observations will significantly increase our understanding of the Moon. Since the exact arrival date and the orbital parameters of the SMART-1 spacecraft are not known yet, a more detailed planning of the scientific observations will follow in the near future. ?? 2004 Elsevier Ltd. All rights reserved.

    20. The infrared moving object detection and security detection related algorithms based on W4 and frame difference

      NASA Astrophysics Data System (ADS)

      Yin, Jiale; Liu, Lei; Li, He; Liu, Qiankun

      2016-07-01

      This paper presents the infrared moving object detection and security detection related algorithms in video surveillance based on the classical W4 and frame difference algorithm. Classical W4 algorithm is one of the powerful background subtraction algorithms applying to infrared images which can accurately, integrally and quickly detect moving object. However, the classical W4 algorithm can only overcome the deficiency in the slight movement of background. The error will become bigger and bigger for long-term surveillance system since the background model is unchanged once established. In this paper, we present the detection algorithm based on the classical W4 and frame difference. It cannot only overcome the shortcoming of falsely detecting because of state mutations from background, but also eliminate holes caused by frame difference. Based on these we further design various security detection related algorithms such as illegal intrusion alarm, illegal persistence alarm and illegal displacement alarm. We compare our method with the classical W4, frame difference, and other state-of-the-art methods. Experiments detailed in this paper show the method proposed in this paper outperforms the classical W4 and frame difference and serves well for the security detection related algorithms.

    1. Massive Young Stellar Object W42-MME: the Discovery of an Infrared Jet Using VLT/NACO Near-infrared Images

      NASA Astrophysics Data System (ADS)

      Dewangan, L. K.; Mayya, Y. D.; Luna, A.; Ojha, D. K.

      2015-04-01

      We report on the discovery of an infrared jet from a deeply embedded infrared counterpart of the 6.7 GHz methanol maser emission (MME) in W42 (i.e., W42-MME). We show that W42-MME drives a parsec-scale H2 outflow, with the detection of a bow shock feature at ˜0.52 pc to the north. The inner ˜0.4 pc part of the H2 outflow has a position angle of ˜18° and the position angle of ˜40° is found farther away on either side of the outflow from W42-MME. W42-MME is detected at wavelengths longer than 2.2 μm and is a massive young stellar object with an estimated stellar mass of 19 ± 4 {{M}⊙ }. We map the inner circumstellar environment of W42-MME using Very Large Telescope (VLT)/NACO adaptive optics Ks and L‧ observations at resolutions of ˜0.″ 2 and ˜0.″1, respectively. We discover a collimated jet in the inner 4500 AU using the L‧ band, which contains prominent Brα line emission. The jet is located inside an envelope/cavity (extent ˜10,640 AU) that is tapered at both ends and is oriented along the north-south direction. Such observed morphology of the outflow cavity around the massive star is scarcely known and is very crucial for understanding the jet-outflow formation process in massive star formation. Along the flow axis, which is parallel to the previously known magnetic field, two blobs are found in both the NACO images at distances of ˜11800 AU, located symmetrically from W42-MME. The observed W42-MME jet-outflow configuration can be used to constrain the jet launching and jet collimation models in massive star formation.

    2. High-resolution reconstruction of objects from cloud-covered infrared images

      NASA Astrophysics Data System (ADS)

      Wang, Jing; Ralph, Jason F.; Goulermas, John Y.

      2009-05-01

      FLIR images are essential for the detection and recognition of ground targets. Small targets can be enhanced using super-resolution techniques to improve the effective resolution of the target area using a sequence of low-resolution images. However, when there is significant cloud cover, several problems can arise: clouds can obscure a target (partially or fully), they can affect the accuracy of image registration algorithms, and they can reduce the contrast of the object against the background. To reconstruct an image in the presence of cloud cover, image correlation metrics from optical flow and a robust super-resolution algorithm have been used to compile a 'best' frame.

    3. The gas environment of the young stellar object GL 2591 studied by infrared spectroscopy

      NASA Technical Reports Server (NTRS)

      Mitchell, George F.; Curry, Charles; Maillard, Jean-Pierre; Allen, Mark

      1989-01-01

      High-resolution M band (4.6 microns) spectroscopy of GL 2591 is presented. Physical structures noted include an absorption feature with an outflow velocity of about 17 km/s, cold gas (identified with the core of the molecular cloud within which the object is embedded), and very broad C-12O lines formed in a neutral wind. The detection of hot low-velocity gas together with warm high-velocity gas suggests the scenario of a warm neutral wind accelerating from an accretion disk.

    4. The gas environment of the young stellar object GL 2591 studied by infrared spectroscopy

      SciTech Connect

      Mitchell, G.F.; Curry, C.; Maillard, J.; Allen, M.; CNR, Institut d'Astrophysique, Paris; California Institute of Technology, Pasadena )

      1989-06-01

      High-resolution M band (4.6 microns) spectroscopy of GL 2591 is presented. Physical structures noted include an absorption feature with an outflow velocity of about 17 km/s, cold gas (identified with the core of the molecular cloud within which the object is embedded), and very broad C-12O lines formed in a neutral wind. The detection of hot low-velocity gas together with warm high-velocity gas suggests the scenario of a warm neutral wind accelerating from an accretion disk. 32 refs.

    5. Infrared and Radio Observations of a Small Group of Protostellar Objects in the Molecular Core, L1251-C

      NASA Astrophysics Data System (ADS)

      Kim, Jungha; Lee, Jeong-Eun; Choi, Minho; Bourke, Tyler L.; Evans, Neal J., II; Di Francesco, James; Cieza, Lucas A.; Dunham, Michael M.; Kang, Miju

      2015-05-01

      We present a multi-wavelength observational study of a low-mass star-forming region, L1251-C, with observational results at wavelengths from the near-infrared to the millimeter. Spitzer Space Telescope observations confirmed that IRAS 22343+7501 is a small group of protostellar objects. The extended emission in the east-west direction with its intensity peak at the center of L1251A has been detected at 350 and 850 μm with the Caltech Submillimeter Observatory and James Clerk Maxwell telescopes, tracing dense envelope material around L1251A. The single-dish data from the Korean VLBI Network and TRAO telescopes show inconsistencies between the intensity peaks of several molecular emission lines and that of the continuum emission, suggesting complex distributions of molecular abundances around L1251A. The Submillimeter Array interferometer data, however, show intensity peaks of CO 2-1 and 13CO 2-1 located at the position of IRS 1, which is both the brightest source in the Infrared Array Camera image and the weakest source in the 1.3 mm dust-continuum map. IRS 1 is the strongest candidate for the driving source of the newly detected compact CO 2-1 outflow. Over the entire region (14‧ × 14‧) of L125l-C, 3 Class I and 16 Class II sources have been detected, including three young stellar objects (YSOs) in L1251A. A comparison between the average projected distance among the 19 YSOs in L1251-C and that among the 3 YSOs in L1251A suggests that L1251-C is an example of low-mass cluster formation where protostellar objects form in a small group.

    6. Algorithms for Planning Multi-Object Spectroscopy Observations with the JWST Near-Infrared Spectrograph

      NASA Astrophysics Data System (ADS)

      Karakla, Diane M.; Pontoppidan, K.; Shyrokov, A.; Beck, T. L.; Valenti, J. A.; Soderblom, D. R.; Tumlinson, J.; Muzerolle, J.

      2014-01-01

      Planning observations for the JWST NIRSpec Multi-Object Spectroscopy will be complex because of the fixed-grid nature of the Micro-Shutter Arrays (MSAs) used for this instrument mode. Two algorithms have been incorporated into the 'MSA Planning Tool' (MPT) in the Astronomers Proposal Tools (APT) for this NIRSpec observation planning process. The 'Basic Algorithm' and the 'Constrained Algorithm' both determine a set of on-sky pointing positions which yield an optimal number of science sources observed per MSA shutter configuration, but these algorithms have different strategies for generating their observing plans. The Basic algorithm uses a defined set of fixed dithers specified by the observer, while the Constrained algorithm can more flexibly define dithers by merely constraining offsets from one pointing position to the next. Each algorithm offers advantages for different observing cases. This poster describes the two algorithms and their products, and clarifies observing cases where clear planning advantages are offered by each.

    7. Multi-Object Spectroscopy with the James Webb Space Telescope’s Near Infrared Spectrograph: Observing Resolved Stellar Populations

      NASA Astrophysics Data System (ADS)

      Gilbert, Karoline; Karakla, Diane M.; Beck, Tracy

      2015-08-01

      The James Webb Space Telescope’s (JWST) Near Infrared Spectrograph (NIRSpec) will provide a multi-object spectroscopy mode through the four Micro-Shutter Arrays (MSAs). Each MSA is a grid of contiguous shutters that can be configured to form slits on more than 100 astronomical targets simultaneously. The combination of JWST’s sensitivity and superb resolution in the infrared and NIRSpec’s full wavelength coverage from 0.6 to 5 μm will open new parameter space for studies of galaxies and resolved stellar populations alike. We describe a NIRSpec MSA observing scenario for obtaining spectroscopy of individual stars in an external galaxy, and investigate the technical challenges posed by this scenario. We examine the multiplexing capability of the MSA as a function of the possible MSA configuration design choices, and investigate the primary sources of error in velocity measurements and the prospects for minimizing them. We give examples of how this and other use cases are guiding development of the NIRSpec user interfaces, including proposal planning and pipeline calibrations.

    8. Near-infrared spectra of ISO selected Chamaeleon I young stellar objects

      NASA Astrophysics Data System (ADS)

      Gómez, M.; Persi, P.

      2002-07-01

      We present 0.95-2.5 mu m moderate (R ~ 500) resolution spectra of 19 ISOCAM detected sources in the Chamaeleon I dark cloud. Thirteen of these stars are candidate very low mass members of the cloud proposed by Persi et al. (\\cite{per00}) on basis of the mid-IR color excess. The sample also includes a bona-fide young brown dwarf (Cha Hα 1), a transition - stellar/sub-stellar - object (Cha Hα 2), one previously known T Tauri star (Sz 33) and three ISOCAM sources with no mid-IR excess. The spectra of the mid-IR color excess sources are relatively flat and featureless in this wavelength range. Both atomic and molecular lines (when in absorption) are partially veiled suggesting the presence of continuum emission from circumstellar dust. In addition some of the sources show Paschen and Brackett lines in emission. We apply the 2 mu m water vapor index defined by Wilking et al. (\\cite{wil99}) to estimate spectral types. These stars have spectral types M0-8. We use Persi et al.'s stellar luminosity determinations, in combination with D'Antona & Mazzitelli latest pre-main sequence evolutionary tracks, to estimate masses and ages. The ISOCAM detected mid-IR excess sources have sub-solar masses down to the H-burning limit and a median age of few x106 yr, in good agreement with the higher mass members of this cloud. Based on observations collected at the European Southern Observatory, Chile, (ESO proposal N.65.I-0054).

    9. Robust detection of small infrared objects in maritime scenarios using local minimum patterns and spatio-temporal context

      NASA Astrophysics Data System (ADS)

      Qi, Baojun; Wu, Tao; He, Hangen

      2012-02-01

      Here, we describe a novel approach for small surface object detection with an onboard infrared (IR) camera working in maritime scenes. First, we propose a simple but effective tool called the local minimum patterns (LMP), which are theoretically the approximated coefficients of some stationary wavelet transforms, for single image background estimation. Second, potential objects are segmented by an adaptive threshold estimated from the saliency map, which is obtained by background subtraction. Using the LMP based wavelet transforms and the histogram of the saliency map, the threshold can be automatically determined by singularity analysis. Next, we localize potential objects by our proposed fast clustering algorithm, which, compared with popular K-Means, is much faster and less sensitive to noises. To make the surveillance system more reliable, we finally discuss how to integrate multiple cues, such as scene geometry constraints and spatio-temporal context, into detections by Bayesian inference. The proposed method has shown to be both effective and efficient by our extensive experiments on some challenging data sets with a competitive performance over some state-of-the-art techniques.

    10. Investigation of small solar system objects with the space telescope

      NASA Technical Reports Server (NTRS)

      Morrison, D.

      1979-01-01

      The application of the space telescope (ST) to study small objects in the solar system in order to understand the birth and the early evolution of the solar system is discussed. The upper size limit of the small bodies is defined as approximately 5000 km and includes planetary satellites, planetary rings, asteroids, and comets.The use of the astronomical instruments aboard the ST, such as the faint object camera, ultraviolet and infrared spectrometers, and spectrophotometers, to study the small solar system objects is discussed.

    11. Properties of galaxies at the faint end of the Hα luminosity function at z ~ 0.62

      NASA Astrophysics Data System (ADS)

      Gómez-Guijarro, Carlos; Gallego, Jesús; Villar, Víctor; Rodríguez-Muñoz, Lucía; Clément, Benjamin; Cuby, Jean-Gabriel

      2016-07-01

      Context. Studies measuring the star formation rate density, luminosity function, and properties of star-forming galaxies are numerous. However, it exists a gap at 0.5 < z < 0.8 in Hα-based studies. Aims: Our main goal is to study the properties of a sample of faint Hα emitters at z ~ 0.62. We focus on their contribution to the faint end of the luminosity function and derived star formation rate density, characterising their morphologies and basic photometric and spectroscopic properties. Methods: We use a narrow-band technique in the near-infrared, with a filter centred at 1.06 μm. The data come from ultra-deep VLT/HAWK-I observations in the GOODS-S field with a total of 31.9 h in the narrow-band filter. In addition to our survey, we mainly make use of ancillary data coming from the CANDELS and Rainbow Cosmological Surveys Database, from the 3D-HST for comparison, and also spectra from the literature. We perform a visual classification of the sample and study their morphologies from structural parameters available in CANDELS. In order to obtain the luminosity function, we apply a traditional V/Vmax method and perform individual extinction corrections for each object to accurately trace the shape of the function. Results: Our 28 Hα-selected sample of faint star-forming galaxies reveals a robust faint-end slope of the luminosity function α = - 1.46-0.08+0.16 . The derived star formation rate density at z ~ 0.62 is ρSFR = 0.036-0.008+0.012 M⊙ yr-1 Mpc-3 . The sample is mainly composed of disks, but an important contribution of compact galaxies with Sérsic indexes n ~ 2 display the highest specific star formation rates. Conclusions: The luminosity function at z ~ 0.62 from our ultra-deep data points towards a steeper α when an individual extinction correction for each object is applied. Compact galaxies are low-mass, low-luminosity, and starburst-dominated objects with a light profile in an intermediate stage from early to late types. Based on observations

    12. On the clustering of faint red galaxies

      NASA Astrophysics Data System (ADS)

      Xu, Haojie; Zheng, Zheng; Guo, Hong; Zhu, Ju; Zehavi, Idit

      2016-08-01

      Faint red galaxies in the Sloan Digital Sky Survey show a puzzling clustering pattern in previous measurements. In the two-point correlation function (2PCF), they appear to be strongly clustered on small scales, indicating a tendency to reside in massive haloes as satellite galaxies. However, their weak clustering on large scales suggests that they are more likely to be found in low-mass haloes. The interpretation of the clustering pattern suffers from the large sample variance in the 2PCF measurements, given the small volume of the volume-limited sample of such faint galaxies. We present improved clustering measurements of faint galaxies by making a full use of a flux-limited sample to obtain volume-limited measurements with an increased effective volume. In the improved 2PCF measurements, the fractional uncertainties on large scales drop by more than 40 per cent, and the strong contrast between small-scale and large-scale clustering amplitudes seen in previous work is no longer prominent. From halo occupation distribution modelling of the measurements, we find that a considerable fraction of faint red galaxies to be satellites in massive haloes, a scenario supported by the strong covariance of small-scale 2PCF measurements and the relative spatial distribution of faint red galaxies and luminous galaxies. However, the satellite fraction is found to be degenerate with the slope of the distribution profile of satellites in inner haloes. We compare the modelling results with semi-analytic model predictions and discuss the implications.

    13. The Faint Counterparts of MAMBO Millimeter Sources near the New Technology Telescope Deep Field

      NASA Astrophysics Data System (ADS)

      Dannerbauer, H.; Lehnert, M. D.; Lutz, D.; Tacconi, L.; Bertoldi, F.; Carilli, C.; Genzel, R.; Menten, K. M.

      2004-05-01

      We discuss identifications for 18 sources from our Max-Planck-Millimeter-Bolometer (MAMBO) 1.2 mm survey of the region surrounding the NTT Deep Field. We have obtained accurate positions from Very Large Array 1.4 GHz interferometry, and in a few cases IRAM millimeter interferometry, and have also made deep BVRIzJK imaging at ESO. We find thirteen 1.2 mm sources associated with optical/near-infrared objects in the magnitude range K=19.0-22.5, while five are blank fields at K>22. We argue from a comparison of optical/near-infrared photometric redshifts and radio/millimeter redshift estimates that two of the 13 optical/near-infrared objects are likely foreground objects distinct from the dust sources, one of them possibly lensing the millimeter source. The median redshift of the radio-identified millimeter sources is ~2.6 from the radio/millimeter estimator, and the median optical/near-infrared photometric redshifts for the objects with counterparts is ~2.1. This suggests that those radio-identified millimeter sources without optical/near-infrared counterparts tend to lie at higher redshifts than those with optical/near-infrared counterparts. Compared to published identifications of objects from 850 μm surveys of similar depth, the median K and I magnitudes of our counterparts are roughly 2 mag fainter, and the dispersion of I-K colors is less. Real differences in the median redshifts, residual misidentifications with bright objects, cosmic variance, and small-number statistics are likely to contribute to this significant difference, which also affects redshift measurement strategies. Some of the counterparts are red in J-K (>~20%), but the contribution of such millimeter objects to the recently studied population of near-infrared-selected (Js-Ks>2.3) high-redshift galaxies is only of order a few percent. The recovery rate of MAMBO sources by preselection of optically faint radio sources is relatively low (~25%), in contrast to some claims of a higher rate for

    14. Particle-based ablation model for faint meteors

      NASA Astrophysics Data System (ADS)

      Stokan, E.; Campbell-Brown, M.

      2014-07-01

      Modeling the ablation of meteoroids as they enter the atmosphere is a way of determining their physical structure and elemental composition. This can provide insight into the structure of parent bodies when combined with an orbit computed from observations. The Canadian Automated Meteor Observatory (CAMO) is a source of new, high-resolution observations of faint meteors [1]. These faint objects tend to have pre-atmospheric masses around 10^{-5} kg, corresponding to a radius of 1 mm. A wide-field camera with a 28° field of view provides guidance to a high-resolution camera that tracks meteors in flight with 1.5° field of view. Meteors are recorded with a scale of 4 m per pixel at a range of 135 km, at 110 frames per second, allowing us to investigate detailed meteor morphology. This serves as an important new constraint for ablation models, in addition to meteor brightness (lightcurves) and meteoroid deceleration. High-resolution observations of faint meteors have revealed that contemporary ablation models are not able to predict meteor morphology, even while matching the observed lightcurve and meteoroid deceleration [2]. This implies that other physical processes, in addition to fragmentation, must be considered for faint meteor ablation. We present a new, particle-based approach to modeling the ablation of small meteoroids. In this model, we simulate the collisions between atmospheric particles and the meteoroid to determine the rate of evaporation and deceleration. Subsequent collisions simulated between evaporated meteoroid particles and ambient atmospheric particles then produce light that would be observed by high-resolution cameras. Preliminary results show simultaneous agreement with meteor morphology, lightcurves, and decelerations recorded with CAMO. A sample comparison of simulated and observed meteor morphology is given in the attached figure. Several meteoroids are well-represented as solid, stony bodies, but some require modeling as a dustball [3

    15. Design of high-performance adaptive objective lens with large optical depth scanning range for ultrabroad near infrared microscopic imaging

      PubMed Central

      Lan, Gongpu; Mauger, Thomas F.; Li, Guoqiang

      2015-01-01

      We report on the theory and design of adaptive objective lens for ultra broadband near infrared light imaging with large dynamic optical depth scanning range by using an embedded tunable lens, which can find wide applications in deep tissue biomedical imaging systems, such as confocal microscope, optical coherence tomography (OCT), two-photon microscopy, etc., both in vivo and ex vivo. This design is based on, but not limited to, a home-made prototype of liquid-filled membrane lens with a clear aperture of 8mm and the thickness of 2.55mm ~3.18mm. It is beneficial to have an adaptive objective lens which allows an extended depth scanning range larger than the focal length zoom range, since this will keep the magnification of the whole system, numerical aperture (NA), field of view (FOV), and resolution more consistent. To achieve this goal, a systematic theory is presented, for the first time to our acknowledgment, by inserting the varifocal lens in between a front and a back solid lens group. The designed objective has a compact size (10mm-diameter and 15mm-length), ultrabroad working bandwidth (760nm - 920nm), a large depth scanning range (7.36mm in air) — 1.533 times of focal length zoom range (4.8mm in air), and a FOV around 1mm × 1mm. Diffraction-limited performance can be achieved within this ultrabroad bandwidth through all the scanning depth (the resolution is 2.22 μm - 2.81 μm, calculated at the wavelength of 800nm with the NA of 0.214 - 0.171). The chromatic focal shift value is within the depth of focus (field). The chromatic difference in distortion is nearly zero and the maximum distortion is less than 0.05%. PMID:26417508

    16. Direct Imaging of Faint Companions

      NASA Astrophysics Data System (ADS)

      Claudi, Riccardo

      The exoplanets around stars in the solar neighborhood are expected to be bright enough for us to characterize them with direct imaging; however, they are much fainter than their parent stars, and separated by very small angles, so conventional imaging techniques are totally inadequate, and new methods are needed. The direct imaging of exoplanets is extremely challenging. Jupiter is 109 times fainter than our Sun in reflected visible light. A direct imaging instrument for exoplanets must suppress (1) the bright star image and diffraction pattern and (2) the stellar scattered light from imperfections in the telescope. The main goal of high-contrast imaging is primarily to discover and characterize extrasolar planetary systems. High-contrast observations, in optical and infrared astronomy, are defined as any observation requiring a technique to reveal a low mass companion that is so close to the primary, brighter by a factor of at least 105, that optical effects hinder or prevent the collection of photons directly from the target of observation. To overcome this, astronomers combined large telescopes (to reduce the impact of diffraction), adaptive optics (to correct for phase errors induced by atmospheric turbulence), and sophisticated image processing.

    17. The LUCIFER MOS: a full cryogenic mask handling unit for a near-infrared multi-object spectrograph

      NASA Astrophysics Data System (ADS)

      Buschkamp, Peter; Hofmann, Reiner; Gemperlein, Hans; Polsterer, Kai; Ageorges, Nancy; Eisenhauer, Frank; Lederer, Reinhard; Honsberg, Mathias; Haug, Marcus; Eibl, Johann; Seifert, Walter; Genzel, Reinhard

      2010-07-01

      The LUCIFER-MOS unit is the full cryogenic mask-exchange unit for the near-infrared multi-object spectrograph LUCIFER at the Large Binocular Telescope. We present the design and functionality of this unique device. In LUCIFER the masks are stored, handled, and placed in the focal plane under cryogenic conditions at all times, resulting in very low thermal background emission from the masks during observations. All mask manipulations are done by a novel cryogenic mask handling robot that can individually address up to 33 fixed and user-provided masks and place them in the focal plane with high accuracy. A complete mask exchange cycle is done in less than five minutes and can be run in every instrument position and state reducing instrument setup time during science observations to a minimum. Exchange of old and new MOS masks is likewise done under cryogenic conditions using a unique exchange drive mechanism and two auxiliary cryostats that attach to the main instrument cryostat.

    18. Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer Observations of the GLIMPSE9 Stellar Cluster

      NASA Astrophysics Data System (ADS)

      Messineo, Maria; Figer, Donald F.; Davies, Ben; Kudritzki, R. P.; Rich, R. Michael; MacKenty, John; Trombley, Christine

      2010-01-01

      We present Hubble Space Telescope/Near-Infrared Camera and Multi-Object Spectrometer photometry, and low-resolution K-band spectra of the GLIMPSE9 stellar cluster. The newly obtained color-magnitude diagram shows a cluster sequence with H - KS = ~1 mag, indicating an interstellar extinction A _K_s = 1.6 ± 0.2 mag. The spectra of the three brightest stars show deep CO band heads, which indicate red supergiants with spectral type M1-M2. Two 09-B2 supergiants are also identified, which yield a spectrophotometric distance of 4.2 ± 0.4 kpc. Presuming that the population is coeval, we derive an age between 15 and 27 Myr, and a total cluster mass of 1600 ± 400 M sun, integrated down to 1 M sun. In the vicinity of GLIMPSE9 are several H II regions and supernova remnants, all of which (including GLIMPSE9) are probably associated with a giant molecular cloud (GMC) in the inner galaxy. GLIMPSE9 probably represents one episode of massive star formation in this GMC. We have identified several other candidate stellar clusters of the same complex.

    19. Faint detection of exoplanets in microlensing surveys

      SciTech Connect

      Brown, Robert A.

      2014-06-20

      We propose a new approach to discovering faint microlensing signals below traditional thresholds, and for estimating the binary-lens mass ratio and the apparent separation from such signals. The events found will be helpful in accurately estimating the true distribution of planetary semimajor axes, which is an important goal of space microlensing surveys.

    20. Thermal-Infrared Surveys of Near-Earth Object Diameters and Albedos with Spitzer and IRTF/MIRSI

      NASA Astrophysics Data System (ADS)

      Mommert, Michael; Trilling, David; Hora, Joseph L.; Chesley, Steven; Emery, Josh; Fazio, Giovanni; Harris, Alan W.; Moskovitz, Nick; Mueller, Michael; Smith, Howard

      2015-08-01

      More than 12000 Near-Earth Objects (NEOs) have been discovered over the past few decades and current discovery surveys find on average 4 new NEOs every night. In comparison to asteroid discovery, the physical characterization of NEOs lags far behind: measured diameters and albedos exist only for roughly 10% of all known NEOs. We describe a current and a future observing program that provide diameter and albedo measurements of a large number of NEOs.In our Spitzer Space Telescope Exploration Science program 'NEOSurvey', we are performing a fast and efficient flux-limited survey in which we measure the diameters and albedos of ~600 NEOs in a total of 710 hrs of observing time. We measure the thermal emission of our targets at 4.5 micron and combine these measurements with optical data in a thermal model. Our diameters and albedos come with highly realistic uncertainties that account for a wide range of potential asteroid properties. Our primary goal is to create a large and uniform catalog of NEO properties, including diameters, albedos, and flux density data. This catalog is publicly accessible and provides the latest results usually within 2 weeks after the observation.Starting in 2016, we will also make use of the refurbished and recommissioned MIRSI mid-infrared imaging camera on NASA's InfraRed Telescope Facility (IRTF) to derive the diameters and albedos of up to 750 NEOs over a period of 3 yrs. MIRSI will be equipped with an optical camera that will allow for simultaneous optical imaging, which will improve our thermal modeling results. With MIRSI, we will focus on newly discovered NEOs that are close to Earth and hence relatively bright.The results from both programs, together with already exisiting diameter and albedo results from the literature, will form the largest database of NEO physical properties available to date. With this data set, we will be able to refine the size distribution of small NEOs and the corresponding impact frequency, and compare the

    1. Faint Lyα Emitters, Star-forming Galaxies, and Damped Lyα Systems

      NASA Astrophysics Data System (ADS)

      Rauch, M.; Haehnelt, M.; Bunker, A.; Becker, G.; Marleau, F.; Graham, J.; Cristiani, S.; Jarvis, M.; Lacey, C.; Morris, S.; Peroux, C.; Roettgering, H.; Theuns, T.

      2008-10-01

      We have discovered a population of faint single line emitters, likely to be identified with faint z˜ 3 Lyα emitters and with the host galaxies of damped Lyman alpha systems. The objects appear to constitute the bulk of the star-forming galaxies detected so far from the ground, and are likely to provide the gaseous reservoir from which present-day Milky way type galaxies have formed. Unlike color-selected (yman break galaxies, these objects appear to have low star-formation rates, relatively strong Lyalpha emission, and low masses, metallicities, and dust content (s.a. arXiv:0711.1354).

    2. Digital image profilers for detecting faint sources which have bright companions, phase 2

      NASA Technical Reports Server (NTRS)

      Morris, Elena; Flint, Graham

      1991-01-01

      A breadboard image profiling system developed for the first phase of this project demonstrated the potential for detecting extremely faint optical sources in the presence of light companions. Experimental data derived from laboratory testing of the device supports the theory that image profilers of this type may approach the theoretical limit imposed by photon statistics. The objective of Phase 2 of this program is the development of a ground-based multichannel image profiling system capable of detecting faint stellar objects slightly displaced from brighter stars. We have finalized the multichannel image profiling system and attempted three field tests.

    3. Faint Satellites of Outer Planets

      NASA Astrophysics Data System (ADS)

      Veillet, C.

      1982-03-01

      In astronomy, as in other matters, the charm 01 novelty is one of the important lactors that govern the choice 01 the observations. How many objects saw suddenly many eyes or kinds of detectors looking at them, before linding again, some months or years later, their sidereal quietness! ... However, it is often after a long time of regular observations that they confide a (small) part 01 their secrets. The laint satellites 01 planets don't transgress this fortunately approximative rule. The deliciency in observations during many consecutive years makes the determination 01 their motion very difficult, and it is olten too late to make up lor lost time. We shall try to i1lustrate this lact in the next lines using the observations of the systems of Saturn, Uranus and Neptune we made in April 1981 on the DanishESO 1.5-m reflector.

    4. Connecting X-ray and infrared variability among young stellar objects: ruling out potential sources of disk fluctuations

      SciTech Connect

      Flaherty, K. M.; Rieke, G.; Muzerolle, J.; Wolk, S. J.; Gutermuth, R.; Balog, Z.; Herbst, W.; Megeath, S. T.; Furlan, E.

      2014-09-20

      Variability in the infrared emission from disks around pre-main-sequence stars over the course of days to weeks appears to be common, but the physical cause of the changes in disk structure are not constrained. Here we present coordinated monitoring of one young cluster with the Spitzer and Chandra space telescopes aimed at studying the physical source of the variability. In fall 2011 we obtained 10 epochs of Chandra ACIS photometry over a period of 30 days with a roughly 3 day cadence contemporaneous with 20 epochs of Spitzer [3.6], [4.5] photometry over 40 days with a roughly 2 day cadence of the IC 348 cluster. This cadence allows us to search for week- to month-long responses of the infrared emission to changes in the high-energy flux. We find no strong evidence for a direct link between the X-ray and infrared variability on these timescales among 39 cluster members with circumstellar disks. There is no significant correlation between the shape of the infrared and X-ray light curves or between the sizes of the X-ray and infrared variability. Among the stars with an X-ray flare, none showed evidence of a correlated change in the infrared photometry on timescales of days to weeks following the flare. This lack of connection implies that X-ray heating of the planet-forming region of the disk is not significant, although we cannot rule out rapid or instantaneous changes in infrared emission.

    5. OPTICAL/NEAR-INFRARED SELECTION OF RED QUASI-STELLAR OBJECTS: EVIDENCE FOR STEEP EXTINCTION CURVES TOWARD GALACTIC CENTERS?

      SciTech Connect

      Fynbo, J. P. U.; Krogager, J.-K.; Vestergaard, M.; Geier, S.; Venemans, B.; Noterdaeme, P.; Moller, P.; Ledoux, C.

      2013-01-15

      We present the results of a search for red QSOs using a selection based on optical imaging from the Sloan Digital Sky Survey (SDSS) and near-infrared imaging from UKIDSS. Our main goal with the selection is to search for QSOs reddened by foreground dusty absorber galaxies. For a sample of 58 candidates (including 20 objects fulfilling our selection criteria that already have spectra in the SDSS), 46 (79%) are confirmed to be QSOs. The QSOs are predominantly dust-reddened except for a handful at redshifts z {approx}> 3.5. However, the dust is most likely located in the QSO host galaxies (and for two, the reddening is primarily caused by Galactic dust) rather than in the intervening absorbers. More than half of the QSOs show evidence of associated absorption (BAL absorption). Four (7%) of the candidates turned out to be late-type stars, and another four (7%) are compact galaxies. We could not identify the remaining four objects. In terms of their optical spectra, these QSOs are similar to the QSOs selected in the FIRST-2MASS Red Quasar Survey except they are on average fainter, more distant, and only two are detected in the FIRST survey. As per the usual procedure, we estimate the amount of extinction using the SDSS QSO template reddened by Small-Magellanic-Cloud-(SMC) like dust. It is possible to get a good match to the observed (rest-frame ultraviolet) spectra, but it is not possible to match the observed near-IR photometry from UKIDSS for nearly all the reddened QSOs. The most likely reasons are that the SDSS QSO template is too red at optical wavelengths due to contaminating host galaxy light and because the assumed SMC extinction curve is too shallow. Three of the compact galaxies display old stellar populations with ages of several Gyr and masses of about 10{sup 10} M{sub Sun} (based on spectral energy distribution modeling). The inferred stellar densities in these galaxies exceed 10{sup 10} M{sub Sun} kpc{sup -2}, which is among the highest measured for early

    6. Very faint X-ray binaries with XMM-Newton

      NASA Astrophysics Data System (ADS)

      Armas Padilla, M.

      2016-06-01

      A population of very faint X-ray binaries has been discovered in the last years thanks to the improvement in sensitivity and resolution of the new generations of X-ray missions. These systems show anomalously low luminosities, below 10^{36} ergs/sec, challenging our understanding of accretion physics and binary evolution models, and thereby opening new windows for both observational and theoretical work on accretion onto compact objects. XMM-Newton is playing a crucial role in the study of this dim family of objects thanks to its incomparable spectral capabilities at low luminosities. I will review the state-of-the-art of the field and present our XMM results in both black hole and neutron star objects. Finally, I will discuss the possibilities that the new generation of X-ray telescopes offer for this research line.

    7. Multiple-return single-photon counting of light in flight and sensing of non-line-of-sight objects at shortwave infrared wavelengths.

      PubMed

      Laurenzis, Martin; Klein, Jonathan; Bacher, Emmanuel; Metzger, Nicolas

      2015-10-15

      Time-of-flight sensing with single-photon sensitivity enables new approaches for the localization of objects outside a sensor's field of view by analyzing backscattered photons. In this Letter, the authors have studied the application of Geiger-mode avalanche photodiode arrays and eye-safe infrared lasers, and provide experimental data of the direct visualization of backscattering light in flight, and direct vision and indirect vision of targets in line-of-sight and non-line-of-sight configurations at shortwave infrared wavelengths. PMID:26469627

    8. Extreme Faint Flux Imaging with an EMCCD

      NASA Astrophysics Data System (ADS)

      Daigle, Olivier; Carignan, Claude; Gach, Jean-Luc; Guillaume, Christian; Lessard, Simon; Fortin, Charles-Anthony; Blais-Ouellette, Sébastien

      2009-08-01

      An EMCCD camera, designed from the ground up for extreme faint flux imaging, is presented. CCCP, the CCD Controller for Counting Photons, has been integrated with a CCD97 EMCCD from e2v technologies into a scientific camera at the Laboratoire d'Astrophysique Expérimentale (LAE), Université de Montréal. This new camera achieves subelectron readout noise and very low clock-induced charge (CIC) levels, which are mandatory for extreme faint flux imaging. It has been characterized in laboratory and used on the Observatoire du Mont Mégantic 1.6 m telescope. The performance of the camera is discussed and experimental data with the first scientific data are presented.

    9. Herschel-ATLAS: the far-infrared properties and star formation rates of broad absorption line quasi-stellar objects

      NASA Astrophysics Data System (ADS)

      Cao Orjales, J. M.; Stevens, J. A.; Jarvis, M. J.; Smith, D. J. B.; Hardcastle, M. J.; Auld, R.; Baes, M.; Cava, A.; Clements, D. L.; Cooray, A.; Coppin, K.; Dariush, A.; De Zotti, G.; Dunne, L.; Dye, S.; Eales, S.; Hopwood, R.; Hoyos, C.; Ibar, E.; Ivison, R. J.; Maddox, S.; Page, M. J.; Valiante, E.

      2012-12-01

      We have used data from the Herschel Astrophysical Terahertz Large-Area Survey (H-ATLAS) at 250, 350 and 500 μm to determine the far-infrared (FIR) properties of 50 broad absorption line quasars (BAL QSOs). Our sample contains 49 high-ionization BAL QSOs (HiBALs) and one low-ionization BAL QSO (LoBAL) which are compared against a sample of 329 non-BAL QSOs. These samples are matched over the redshift range 1.5 ≤ z < 2.3 and in absolute i-band magnitude over the range -28 ≤ Mi ≤ -24. Of these, three BAL QSOs (HiBALs) and 27 non-BAL QSOs are detected at the >5 σ level. We calculate star formation rates (SFRs) for our individually detected HiBAL QSOs and the non-detected LoBAL QSO as well as average SFRs for the BAL and non-BAL QSO samples based on stacking the Herschel data. We find no difference between the HiBAL and non-BAL QSO samples in the FIR, even when separated based on differing BAL QSO classifications. Using Mrk 231 as a template, the weighted mean SFR is estimated to be ≈240 ± 21 M⊙ yr-1 for the full sample, although this figure should be treated as an upper limit if active galactic nucleus (AGN)-heated dust makes a contribution to the FIR emission. Despite tentative claims in the literature, we do not find a dependence of C IV equivalent width on FIR emission, suggesting that the strength of any outflow in these objects is not linked to their FIR output. These results strongly suggest that BAL QSOs (more specifically HiBALs) can be accommodated within a simple AGN unified scheme in which our line of sight to the nucleus intersects outflowing material. Models in which HiBALs are caught towards the end of a period of enhanced spheroid and black hole growth, during which a wind terminates the star formation activity, are not supported by the observed FIR properties. The Herschel-ATLAS is a project with Herschel, which is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important

    10. A possible WISE blazar counterpart of the faint INTEGRAL active galactic nucleus IGR J02341+0228

      NASA Astrophysics Data System (ADS)

      Massaro, F.; Paggi, A.; D'Abrusco, R.

      2012-05-01

      Following the Swift-XRT identification of the counterpart for the faint INTEGRAL active galactic nucleus IGR J02341+0228, associated with a new extragalactic source: QSO B0231+022 (ATEL #4102), we searched in the Wide-field Infrared Survey Explorer (WISE; Wright et al. 2010 AJ, 140, 1868) catalog at the position of the QSO B0231+022 source for an infrared counterpart.

    11. LBT/LUCIFER near-infrared spectroscopy of PV Cephei. An outbursting young stellar object with an asymmetric jet

      NASA Astrophysics Data System (ADS)

      Caratti o Garatti, A.; Garcia Lopez, R.; Weigelt, G.; Tambovtseva, L. V.; Grinin, V. P.; Wheelwright, H.; Ilee, J. D.

      2013-06-01

      Context. Young stellar objects (YSOs) occasionally experience enhanced accretion events, the nature of which is still poorly understood. The discovery of various embedded outbursting YSOs has recently questioned the classical definition of EXors and FUors. Aims: We present a detailed spectroscopic investigation of the young eruptive star PV Cep, to improve our understanding of its nature and characterise its circumstellar environment after its last outburst in 2004. Methods: The analysis of our medium-resolution spectroscopy in the near-infrared (NIR, 0.9-2.35 μm), collected in 2012 at the Large Binocular Telescope with the IR spectrograph LUCIFER, allows us to infer the main stellar parameters (visual extinction, accretion luminosity, mass accretion and ejection rates), and model the inner disc, jet, and wind. Results: The NIR spectrum displays several strong emission lines associated with accretion/ejection activity and circumstellar environment. Our analysis shows that the brightness of PV Cep is fading, as well as the mass accretion rate (2 × 10-7 M⊙ yr-1 in 2012 vs. ~5 × 10-6 M⊙ yr-1 in 2004), which is more than one order of magnitude lower than in the outburst phase. Among the several emission lines, only the [Fe ii] intensity increased after the outburst. The observed [Fe ii] emission delineates blue- and red-shifted lobes, both with high- and low-velocity components, which trace an asymmetric jet and wind, respectively. The observed emission in the jet has a dynamical age of 7-8 years, indicating that it was produced during the last outburst. The visual extinction decreases moving from the red-shifted (AV(red) = 10.1 ± 0.7 mag) to the blue-shifted lobe (AV(blue) = 6.5 ± 0.4 mag). We measure an average electron temperature of 17 500 K and electron densities of 30 000 cm-3 and 15 000 cm-3 for the blue and the red lobe, respectively. The mass ejection rate in both lobes is ~1.5 × 10-7 M⊙ yr-1, approximately matching the high accretion rate observed

    12. Determination of astrometry and photometry of faint companions in the presence of residual speckle noise

      NASA Astrophysics Data System (ADS)

      Burke, Daniel; Devaney, Nicholas; Gladysz, Szymon

      In this paper we examine approaches to faint companion detection and estimation in multi-spectral images. We will employ the Hotelling observer which is the optimal linear algorithm for signal detection. We have shown how to use this observer to estimate faint object position and brightness in the presence of residual speckle which usually limit astrometric and photometric techniques. These speckles can be reduced by differential imaging techniques such as Angular Differential Imaging and Spectral Differential Imaging. Here we present results based on simulations of adaptive optics corrected images from an ELT which contain quasi-static speckle noise. The simulation includes Angular Differential Imaging to reduce the residual speckle and subsequent multi-wavelenght processing. We examine the feasibility of this approach on simulated ELT observations of faint companions.

    13. MOVING OBJECTS IN THE HUBBLE ULTRA DEEP FIELD

      SciTech Connect

      Kilic, Mukremin; Gianninas, Alexandros; Von Hippel, Ted E-mail: alexg@nhn.ou.edu

      2013-09-01

      We identify proper motion objects in the Hubble Ultra Deep Field (UDF) using the optical data from the original UDF program in 2004 and the near-infrared data from the 128 orbit UDF 2012 campaign. There are 12 sources brighter than I = 27 mag that display >3{sigma} significant proper motions. We do not find any proper motion objects fainter than this magnitude limit. Combining optical and near-infrared photometry, we model the spectral energy distribution of each point-source using stellar templates and state-of-the-art white dwarf models. For I {<=} 27 mag, we identify 23 stars with K0-M6 spectral types and two faint blue objects that are clearly old, thick disk white dwarfs. We measure a thick disk white dwarf space density of 0.1-1.7 Multiplication-Sign 10{sup -3} pc{sup -3} from these two objects. There are no halo white dwarfs in the UDF down to I = 27 mag. Combining the Hubble Deep Field North, South, and the UDF data, we do not see any evidence for dark matter in the form of faint halo white dwarfs, and the observed population of white dwarfs can be explained with the standard Galactic models.

    14. The formation of Jupiter's faint rings

      PubMed

      Burns; Showalter; Hamilton; Nicholson; de Pater I; Ockert-Bell; Thomas

      1999-05-14

      Observations by the Galileo spacecraft and the Keck telescope showed that Jupiter's outermost (gossamer) ring is actually two rings circumscribed by the orbits of the small satellites Amalthea and Thebe. The gossamer rings' unique morphology-especially the rectangular end profiles at the satellite's orbit and the enhanced intensities along the top and bottom edges of the rings-can be explained by collisional ejecta lost from the inclined satellites. The ejecta evolves inward under Poynting-Robertson drag. This mechanism may also explain the origin of Jupiter's main ring and suggests that faint rings may accompany all small inner satellites of the other jovian planets. PMID:10325220

    15. The multi-filter rotating shadowband radiometer (MFRSR) - precision infrared radiometer (PIR) platform in Fairbanks: Scientific objectives

      SciTech Connect

      Stamnes, K.; Leontieva, E.

      1996-04-01

      The multi-filter rotating shadowband radiometer (MFRSR) and precision infrared radiometer (PIR) have been employed at the Geophysical Institute in Fairbanks to check their performance under arctic conditions. Drawing on the experience of the previous measurements in the Arctic, the PIR was equipped with a ventilator to prevent frost and moisture build-up. We adopted the Solar Infrared Observing Sytem (SIROS) concept from the Southern Great Plains Cloud and Radiation Testbed (CART) to allow implementation of the same data processing software for a set of radiation and meteorological instruments. To validate the level of performance of the whole SIROS prior to its incorporation into the North Slope of Alaska (NSA) Cloud and Radiation Testbed Site instrumental suite for flux radiatin measurements, the comparison between measurements and model predictions will be undertaken to assess the MFRSR-PIR Arctic data quality.

    16. Strong Near-Infrared Emission Interior to the Dust Sublimation Radius of Young Stellar Objects MWC 275 and AB Aurigae

      NASA Astrophysics Data System (ADS)

      Tannirkulam, A.; Monnier, J. D.; Millan-Gabet, R.; Harries, T. J.; Pedretti, E.; ten Brummelaar, T. A.; McAlister, H.; Turner, N.; Sturmann, J.; Sturmann, L.

      2008-04-01

      Using the longest optical-interferometeric baselines currently available, we have detected strong near-infrared (NIR) emission from inside the dust destruction radius of Herbig Ae stars MWC 275 and AB Aur. Our submilliarcsecond resolution observations unambiguously place the emission between the dust destruction radius and the magnetospheric corotation radius. We argue that this new component corresponds to hot gas inside the dust sublimation radius, confirming recent claims based on spectrally resolved interferometry and dust evaporation front modeling.

    17. Near-Infrared and Optical colors of Trans-Neptunian Objects and Centaurs from Ground-Based Observations in Support of Spitzer Observations

      NASA Astrophysics Data System (ADS)

      Lejoly, Cassandra; Mommert, Michael; Trilling, David; Pinilla-Alonso, Noemi; Emery, Josh; Melton, Chad; McCarthy, Don; Kulesa, Craig

      2015-11-01

      Trans-Neptunian objects and Centaurs are small icy bodies located beyond the orbit of Neptune and between the orbits of Neptune and Jupiter, respectively. These objects are composed of organic material, of silicate minerals and of different ices, including H2O, CH4, N2 and CH3OH. Determining the composition of such object usually requires spectroscopic measurements on large telescopes. However, we can constrain the compositions of these objects by measuring their near-infrared colors that -- in combination with existing data from the Spitzer Space Telescope -- can indicate surface composition.. We will present near-infrared magnitudes and colors of at least 24 trans-Neptunian objects and 3 Centaurs obtained in ground-based observations. We observed with Gemini, UKIRT, and the 90" Bok Telescope on Kitt Peak between 2011 and 2015. The combination of our data with existing Spitzer Space Telescope data enables us to identify spectral slope up to 4.5 μm and provides rough information on spectral bands, which are important clues on the surface composition of our targets. We will present preliminary results on the compositional analysis for select targets. This work was supported by the Spitzer Science Center and NASA's Planetary Astronomy program.

    18. An X-Ray and Infrared Survey of the Lynds 1228 Cloud Core

      NASA Astrophysics Data System (ADS)

      Skinner, Stephen L.; Rebull, Luisa; Güdel, Manuel

      2014-04-01

      The nearby Lynds 1228 (L1228) dark cloud at a distance of ~200 pc is known to harbor several young stars including the driving sources of the giant HH 199 and HH 200 Herbig-Haro (HH) outflows. L1228 has previously been studied at optical, infrared, and radio wavelengths but not in X-rays. We present results of a sensitive 37 ks Chandra ACIS-I X-ray observation of the L1228 core region. Chandra detected 60 X-ray sources, most of which are faint (<40 counts) and non-variable. Infrared counterparts were identified for 53 of the 60 X-ray sources using archival data from the Two Micron All-Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer. Object classes were assigned using mid-IR colors for those objects with complete photometry, most of which were found to have colors consistent with extragalactic background sources. Seven young stellar object candidates were identified including the class I protostar HH 200-IRS which was detected as a faint hard X-ray source. No X-ray emission was detected from the luminous protostar HH 199-IRS. We summarize the X-ray and infrared properties of the detected sources and provide IR spectral energy distribution modeling of high-interest objects including the protostars driving the HH outflows.

    19. An X-ray and infrared survey of the Lynds 1228 cloud core

      SciTech Connect

      Skinner, Stephen L.; Rebull, Luisa

      2014-04-01

      The nearby Lynds 1228 (L1228) dark cloud at a distance of ∼200 pc is known to harbor several young stars including the driving sources of the giant HH 199 and HH 200 Herbig-Haro (HH) outflows. L1228 has previously been studied at optical, infrared, and radio wavelengths but not in X-rays. We present results of a sensitive 37 ks Chandra ACIS-I X-ray observation of the L1228 core region. Chandra detected 60 X-ray sources, most of which are faint (<40 counts) and non-variable. Infrared counterparts were identified for 53 of the 60 X-ray sources using archival data from the Two Micron All-Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer. Object classes were assigned using mid-IR colors for those objects with complete photometry, most of which were found to have colors consistent with extragalactic background sources. Seven young stellar object candidates were identified including the class I protostar HH 200-IRS which was detected as a faint hard X-ray source. No X-ray emission was detected from the luminous protostar HH 199-IRS. We summarize the X-ray and infrared properties of the detected sources and provide IR spectral energy distribution modeling of high-interest objects including the protostars driving the HH outflows.

    20. Physical and Chemical Properties of Protocluster Clumps and Massive Young Stellar Objects Associated to Infrared Dark Clouds

      NASA Astrophysics Data System (ADS)

      Gomez Gonzalez, Laura

      2012-01-01

      The study of high-mass stars is important not only because of the effects they produce in their environment through outflows, expanding HII regions, stellar winds, and eventually supernova shock waves, but also because they play a crucial role in estimating star formation rates in other galaxies. Although we have an accepted evolutionary scenario that explains (isolated) low-mass star formation, the processes that produce massive stars (M_star > 8 M_sol) and star clusters, especially their earliest stages, are not well understood. The newly discovered class of interstellar clouds now termed infrared dark clouds (IRDCs) represent excellent laboratories to study the earliest stages of high-mass star formation given that some of the clumps within them are known to have high masses (~100's M_sol), high densities (n > 10^5 cm^-3), and low temperatures (10-20K) as expected for the birthplaces of high-mass stars. Some questions remain unanswered: Do IRDCs harbor the very early stages of high-mass star formation, i.e., the pre-protocluster phase? If so, how do they compare with low-mass star formation sites? Is there chemical differentiation in IRDC clumps? What is the mass distribution of IRDCs? In this dissertation and for the first time, a catalog of 12529 IRDC candidates at 24 um has been created using archival data from the MIPSGAL/Spitzer survey, as a first step in searching for the massive pre-protocluster clumps. From this catalog, a sample of ~60 clumps has been selected in order to perform single-pointing observations with the IRAM 30m, Effelsberg 100m, and APEX 12m telescopes. One IRDC clump seems to be a promising candidate for being in the pre-protocluster phase. In addition, molecular line mapping observations have been performed on three clumps within IRDCs and a detailed chemical study of 10 molecular lines has been carried out. A larger difference in column densities and abundances has been found between these clumps and high-m! ass protostellar objects

    1. Development of a simultaneous two-color near-infrared multi-object spectrograph SWIMS for the TAO 6.5-m telescope

      NASA Astrophysics Data System (ADS)

      Motohara, Kentaro; Konishi, Masahiro; Takahashi, Hidenori; Tateuchi, Ken; Kitagawa, Yutaro; Todo, Soya; Kato, Natsuko M.; Ohsawa, Ryou; Aoki, Tsutomu; Asano, Kentaro; Doi, Mamoru; Kamizuka, Takafumi; Kawara, Kimiaki; Kohno, Kotaro; Koshida, Shintaro; Minezaki, Takeo; Miyata, Takashi; Morokuma, Tomoki; Okada, Kazushi; Sako, Shigeyuki; Soyano, Takao; Tamura, Yoichi; Tanabe, Toshihiko; Tanaka, Masuo; Tarusawa, Ken'ichi; Uchiyama, Mizuho; Yoshii, Yuzuru

      2014-07-01

      Simultaneous Color Wide-field Infrared Multi-object Spectrograph, SWIMS, is one of the first generation in- struments for the University of Tokyo Atacama Observatory (TAO) 6.5m Telescope now under construction. A dichroic mirror being inserted in the collimated beam, it is capable of two-color simultaneous imaging with FoV of 9:16φ or R ˜ 1000 multi-object spectroscopy at 0.9-2.5μm wavelength range in one shot, and enables us to carry out efficient NIR imaging/spectroscopic survey of objects such as distant galaxies and young stellar objects. All the major components have been fabricated and we will start integration and laboratory cool-down test in the summer of 2014. After the engineering and initial science observations at the Subaru telescope, SWIMS will be transported to TAO telescope and see the first light in 2018.

    2. Cold H I in faint dwarf galaxies

      NASA Astrophysics Data System (ADS)

      Patra, Narendra Nath; Chengalur, Jayaram N.; Karachentsev, Igor D.; Kaisin, Serafim S.; Begum, Ayesha

      2016-03-01

      We present the results of a study of the amount and distribution of cold atomic gas, as well its correlation with recent star formation in a sample of extremely faint dwarf irregular galaxies. Our sample is drawn from the Faint Irregular Galaxy GMRT Survey (FIGGS) and its extension, FIGGS2. We use two different methods to identify cold atomic gas. In the first method, line-of-sight H I spectra were decomposed into multiple Gaussian components and narrow Gaussian components were identified as cold H I. In the second method, the brightness temperature (TB ) is used as a tracer of cold H I. We find that the amount of cold gas identified using the TB method is significantly larger than the amount of gas identified using Gaussian decomposition. We also find that a large fraction of the cold gas identified using the TB method is spatially coincident with regions of recent star formation, although the converse is not true. That is only a small fraction of the regions with recent star formation are also covered by cold gas. For regions where the star formation and the cold gas overlap, we study the relationship between the star formation rate density and the cold H I column density. We find that the star formation rate density has a power-law dependence on the H I column density, but that the slope of this power law is significantly flatter than that of the canonical Kennicutt-Schmidt relation.

    3. A spectroscopic search for faint secondaries in cataclysmic variables

      NASA Astrophysics Data System (ADS)

      Vande Putte, D.; Smith, Robert Connon; Hawkins, N. A.; Martin, J. S.

      2003-06-01

      The secondary in cataclysmic variables (CVs) is usually detected by cross-correlation of the CV spectrum with that of a K or M dwarf template, to produce a radial velocity curve. Although this method has demonstrated its power, it has its limits in the case of noisy spectra, such as are found when the secondary is faint. A method of coadding spectra, called skew mapping, has been proposed in the past. Gradually, examples of its application are being published; none the less, so far no journal article has described the technique in detail. To answer this need, this paper explores in detail the capabilities of skew mapping when determining the amplitude of the radial velocity for faint secondaries. It demonstrates the power of the method over techniques that are more conventional, when the signal-to-noise ratio is poor. The paper suggests an approach to assessing the quality of results. This leads in the case of the investigated objects to a first tier of results, where we find K2= 127 +/- 23 km s-1 for SY Cnc, K2= 144 +/- 18 km s-1 for RW Sex and K2= 262 +/- 14 km s-1 for UX UMa. These we believe to be the first direct determinations of K2 for these objects. Furthermore, we also obtain K2= 263 +/- 30 km s-1 for RW Tri, close to a skew mapping result obtained elsewhere. In the first three cases, we use these results to derive the mass of the white dwarf companion. A second tier of results includes UU Aqr, EX Hya and LX Ser, for which we propose more tentative values of K2. Clear failures of the method are also discussed (EF Eri, VV Pup and SW Sex).

    4. LUCI in the sky: performance and lessons learned in the first two years of near-infrared multi-object spectroscopy at the LBT

      NASA Astrophysics Data System (ADS)

      Buschkamp, Peter; Seifert, Walter; Polsterer, Kai; Hofmann, Reiner; Gemperlein, Hans; Lederer, Reinhard; Lehmitz, Michael; Naranjo, Vianak; Ageorges, Nancy; Kurk, Jaron; Eisenhauer, Frank; Rabien, Sebastian; Honsberg, Mathias; Genzel, Reinhard

      2012-09-01

      LUCI (former LUCIFER) is the full cryogenic near-infrared multi-object spectrograph and imager at the LBT. It presently allows for seeing limited imaging and multi-object spectroscopy at R~2000-4000 in a 4x4arcmin2 FOV from 0.9 to 2.5 micron. We report on the instrument performance and the lessons learned during the first two years on sky from a technical and operational point of view. We present the upcoming detector upgrade to Hawaii-2 RG arrays and the operating modes to utilize the binocular mode, the LBT facility AO system for diffraction limited imaging as well as to use the wide-field AO correction afforded by the multi-laser GLAO System ARGOS in multi-object spectroscopy.

    5. Near Infrared Astronomical Observing During the Daytime

      NASA Astrophysics Data System (ADS)

      Tinn Chee Jim, Kevin; Pier, Edward Alan; Cognion, Rita L.

      2015-08-01

      Ground-based, near-infrared astronomy has been mostly restriced to nighttime observing with occasional, bright solar system objects observed during the daytime. But for astronomical phenomena that are time-varying on timescales of less than a day, it would be advantageous to be able to gather data during the day and night. We explore some of the limitations of observing in the J, H, and K bands during the daytime. Atmospheric radiative transfer simulations show that K is the optimal common astronomical filter for daytime observations on Mauna Kea, but the J and H filters can also be used. Observations from Mauna Kea show that it is possible to observe objects at least as faint as K=15.5 during the early afternoon, with photometric accuracies only slightly worse than those obtained at night.

    6. Observing Faint Companions Close to Bright Stars

      NASA Astrophysics Data System (ADS)

      Serabyn, Eugene

      2012-04-01

      Progress in a number of technical areas is enabling imaging and interferometric observations at both smaller angular separations from bright stars and at deeper relative contrast levels. Here we discuss recent progress in several ongoing projects at the Jet Propulsion Laboratory. First, extreme adaptive optics wavefront correction has recently enabled the use of very short (i.e., blue) wavelengths to resolve close binaries. Second, phase-based coronagraphy has recently allowed observations of faint companions to within nearly one diffraction beam width of bright stars. Finally, rotating interferometers that can observe inside the diffraction beam of single aperture telescopes are being developed to detect close-in companions and bright exozodiacal dust. This paper presents a very brief summary of the techniques involved, along with some illustrative results.

    7. MEASURING SIZES OF ULTRA-FAINT DWARF GALAXIES

      SciTech Connect

      Munoz, Ricardo R.; Padmanabhan, Nikhil; Geha, Marla

      2012-02-01

      The discovery of ultra-faint dwarf (UFD) galaxies in the halo of the Milky Way extends the faint end of the galaxy luminosity function to a few hundred solar luminosities. This extremely low luminosity regime poses a significant challenge for the photometric characterization of these systems. We present a suite of simulations aimed at understanding how different observational choices related to the properties of a low-luminosity system impact our ability to determine its true structural parameters such as half-light radius and central surface brightness. We focus on estimating half-light radii (on which mass estimates depend linearly) and find that these numbers can have up to 100% uncertainties when relatively shallow photometric surveys, such as the Sloan Digital Sky Survey, are used. Our simulations suggest that to recover structural parameters within 10% or better of their true values: (1) the ratio of the field of view to the half-light radius of the satellite must be greater than three, (2) the total number of stars, including background objects should be larger than 1000, and (3) the central to background stellar density ratio must be higher than 20. If one or more of these criteria are not met, the accuracy of the resulting structural parameters can be significantly compromised. In the context of future surveys such as Large Synoptic Survey Telescope, the latter condition will be closely tied to our ability to remove unresolved background galaxies. Assessing the reliability of measured structural parameters will become increasingly critical as the next generation of deep wide-field surveys detects UFDs beyond the reach of current spectroscopic limits.

    8. First Results from the ISO-IRAS Faint Galaxy Survey

      NASA Technical Reports Server (NTRS)

      Wolstencroft, R. D.; Wehrle, A. E.; Levine, D. A.

      1997-01-01

      We present the first result from the ISO-IRAS Faint Galaxy Survey (IIFGS), a program designed to obtain ISO observations of the most distant and luminous galaxies in the IRAS Faint Source Survey by filling short gaps in the ISO observing schedule with pairs of 12um ISOCAM AND 90um ISOPHOT observation.

    9. Constraints on MACHO Dark Matter from Compact Stellar Systems in Ultra-faint Dwarf Galaxies

      NASA Astrophysics Data System (ADS)

      Brandt, Timothy D.

      2016-06-01

      I show that a recently discovered star cluster near the center of the ultra-faint dwarf galaxy Eridanus II provides strong constraints on massive compact halo objects (MACHOs) of ≳5 M ⊙ as the main component of dark matter. MACHO dark matter will dynamically heat the cluster, driving it to larger sizes and higher velocity dispersions until it dissolves into its host galaxy. The stars in compact ultra-faint dwarf galaxies themselves will be subject to the same dynamical heating; the survival of at least 10 such galaxies places independent limits on MACHO dark matter of masses ≳10 M ⊙. Both Eri II’s cluster and the compact ultra-faint dwarfs are characterized by stellar masses of just a few thousand M ⊙ and half-light radii of 13 pc (for the cluster) and ∼30 pc (for the ultra-faint dwarfs). These systems close the ∼20–100 M ⊙ window of allowed MACHO dark matter and combine with existing constraints from microlensing, wide binaries, and disk kinematics to rule out dark matter composed entirely of MACHOs from ∼10‑7 M ⊙ up to arbitrarily high masses.

    10. Faints, fits, and fatalities from emotion in Shakespeare's characters: survey of the canon

      PubMed Central

      2006-01-01

      Objectives To determine how often Shakespeare's characters faint, fit, or die from extreme emotion; to assess Shakespeare's uniqueness in this regard; and to examine the plausibility of these dramatised events. Design Line by line search through modern editions of these late 16th and early 17th century works for accounts of characters fainting, fitting, or dying while under strong emotion and for no other apparent reason. Data sources All 39 canonical plays by Shakespeare and his three long narrative poems; 18 similar works by seven of Shakespeare's best known contemporaries. Results 10 deaths from strong emotion are recorded by Shakespeare (three occur on stage); all are due to grief, typically at the loss of a loved one. All but two of the deaths are in the playwright's late works. Some deaths are sudden. Another 29 emotion induced deaths are mentioned as possible, but the likelihood of some can be challenged. Transient loss of consciousness is staged or reported in 18 cases (sounding like epilepsy in two) and near fainting in a further 13. Extreme joy is sometimes depicted as a factor in these events. Emotional death and fainting also occur occasionally in works by Shakespeare's contemporaries. Conclusions These dramatic phenomena are part of the early modern belief system but are also plausible by modern understanding of physiology and disease. They teach us not to underestimate the power of the emotions to disturb bodily functions. PMID:17185734

    11. Unveiling the near-infrared structure of the massive-young stellar object NGC 3603 IRS 9A* with sparse aperture masking and spectroastrometry

      NASA Astrophysics Data System (ADS)

      Sanchez-Bermudez, J.; Hummel, C. A.; Tuthill, P.; Alberdi, A.; Schödel, R.; Lacour, S.; Stanke, T.

      2016-04-01

      Context. Contemporary theory holds that massive stars gather mass during their initial phases via accreting disk-like structures. However, conclusive evidence for disks has remained elusive for most massive young objects. This is mainly due to significant observational challenges: objects are rare and located at great distances within dusty, highly opaque environments. Incisive studies, even targeting individual objects, are therefore relevant to the progression of the field. NGC 3603 IRS 9A* is a young massive stellar object that is still surrounded by an envelope of molecular gas for which previous mid-infrared observations with long-baseline interferometry have provided evidence of a plausible disk of 50 mas diameter at its core. Aims: This work aims at a comprehensive study of the physics and morphology of IRS 9A at near-infrared wavelengths. Methods: New sparse aperture-masking interferometry data, taken with the near-infrared camera NACO of the Very Large Telescope (VLT) at Ks and L' wavelengths, were analyzed together with archival high-resolution H2 and Brγ lines obtained with the cryogenic high-resolution infrared schelle spectrograph (CRIRES). Results: The trends in the calibrated visibilities at Ks and L'-bands suggest the presence of a partially resolved compact object with an angular size of ≤30 mas at the core of IRS 9A, together with the presence of over-resolved flux. The spectroastrometric signal of the H2 line, obtained from the CRIRES spectra, shows that this spectral feature proceeds from the large-scale extended emission (~300 mas), while the Brγ line appears to be formed at the core of the object (~20 mas). To better understand the physics that drive IRS 9A, we have performed continuum radiative transfer modeling. Our best model supports the existence of a compact disk with an angular diameter of 20 mas, together with an outer envelope of 1'' exhibiting a polar cavity with an opening angle of ~30°. This model reproduces the MIR morphology

    12. DISCOVERY AND CHARACTERIZATION OF A FAINT STELLAR COMPANION TO THE A3V STAR zeta VIRGINIS

      SciTech Connect

      Hinkley, Sasha; Hillenbrand, Lynne; Oppenheimer, Ben R.; Brenner, Douglas; Zimmerman, Neil; Sivaramakrishnan, Anand; Roberts, Lewis C.; Roberts, Jennifer E.; Burruss, Rick; Shao, Michael; Vasisht, Gautam; Parry, Ian R.; King, David L.; Soummer, Remi; Simon, Michal; Perrin, Marshall D.; Lloyd, James P.; Bouchez, Antonin; Dekany, Richard; Beichman, Charles

      2010-03-20

      Through the combination of high-order adaptive optics and coronagraphy, we report the discovery of a faint stellar companion to the A3V star zeta Virginis. This companion is {approx}7 mag fainter than its host star in the H band, and infrared imaging spanning 4.75 years over five epochs indicates this companion has common proper motion with its host star. Using evolutionary models, we estimate its mass to be 0.168{sup +0.012}{sub -0.016} M{sub sun}, giving a mass ratio for this system q = 0.082{sup +0.007}{sub -0.008}. Assuming the two objects are coeval, this mass suggests an M4V-M7V spectral type for the companion, which is confirmed through {integral} field spectroscopic measurements. We see clear evidence for orbital motion from this companion and are able to constrain the semimajor axis to be {approx}>24.9 AU, the period {approx}>124 yr, and eccentricity {approx}>0.16. Multiplicity studies of higher mass stars are relatively rare, and binary companions such as this one at the extreme low end of the mass ratio distribution are useful additions to surveys incomplete at such a low mass ratio. Moreover, the frequency of binary companions can help to discriminate between binary formation scenarios that predict an abundance of low-mass companions forming from the early fragmentation of a massive circumstellar disk. A system such as this may provide insight into the anomalous X-ray emission from A stars, hypothesized to be from unseen late-type stellar companions. Indeed, we calculate that the presence of this M-dwarf companion easily accounts for the X-ray emission from this star detected by ROSAT.

    13. The Apache Point Observatory Galactic Evolution Experiment (APOGEE) high-resolution near-infrared multi-object fiber spectrograph

      NASA Astrophysics Data System (ADS)

      Wilson, John C.; Hearty, Fred; Skrutskie, Michael F.; Majewski, Steven; Schiavon, Ricardo; Eisenstein, Daniel; Gunn, Jim; Blank, Basil; Henderson, Chuck; Smee, Stephen; Barkhouser, Robert; Harding, Al; Fitzgerald, Greg; Stolberg, Todd; Arns, Jim; Nelson, Matt; Brunner, Sophia; Burton, Adam; Walker, Eric; Lam, Charles; Maseman, Paul; Barr, Jim; Leger, French; Carey, Larry; MacDonald, Nick; Horne, Todd; Young, Erick; Rieke, George; Rieke, Marcia; O'Brien, Tom; Hope, Steve; Krakula, John; Crane, Jeff; Zhao, Bo; Carr, Mike; Harrison, Craig; Stoll, Robert; Vernieri, Mary A.; Holtzman, Jon; Shetrone, Matt; Allende-Prieto, Carlos; Johnson, Jennifer; Frinchaboy, Peter; Zasowski, Gail; Bizyaev, Dmitry; Gillespie, Bruce; Weinberg, David

      2010-07-01

      The Apache Point Observatory Galactic Evolution Experiment (APOGEE) will use a dedicated 300-fiber, narrow-band (1.5-1.7 micron), high resolution (R~30,000), near-infrared spectrograph to survey approximately 100,000 giant stars across the Milky Way. This survey, conducted as part of the Sloan Digital Sky Survey III (SDSS III), will revolutionize our understanding of kinematical and chemical enrichment histories of all Galactic stellar populations. The instrument, currently in fabrication, will be housed in a separate building adjacent to the 2.5 m SDSS telescope and fed light via approximately 45-meter fiber runs from the telescope. The instrument design includes numerous technological challenges and innovations including a gang connector that allows simultaneous connection of all fibers with a single plug to a telescope cartridge that positions the fibers on the sky, numerous places in the fiber train in which focal ratio degradation must be minimized, a large (290 mm x 475 mm elliptically-shaped recorded area) mosaic-VPH, an f/1.4 sixelement refractive camera featuring silicon and fused silica elements with diameters as large as 393 mm, three near-within a custom, LN2-cooled, stainless steel vacuum cryostat with dimensions 1.4 m x 2.3 m x 1.3 m.

    14. HIGH-RESOLUTION MID-INFRARED SPECTROSCOPY OF NGC 7538 IRS 1: PROBING CHEMISTRY IN A MASSIVE YOUNG STELLAR OBJECT

      SciTech Connect

      Knez, Claudia; Lacy, John H.; Evans, Neal J.; Van Dishoeck, Ewine F.; Richter, Matthew J.

      2009-05-01

      We present high-resolution (R = 75,000-100,000) mid-infrared spectra of the high-mass embedded young star IRS 1 in the NGC 7538 star-forming region. Absorption lines from many rotational states of C{sub 2}H{sub 2}, {sup 13}C{sup 12}CH{sub 2}, CH{sub 3}, CH{sub 4}, NH{sub 3}, HCN, HNCO, and CS are seen. The gas temperature, column density, covering factor, line width, and Doppler shift for each molecule are derived. All molecules were fit with two velocity components between -54 and -63 km s{sup -1}. We find high column densities ({approx}10{sup 16} cm{sup -2}) for all the observed molecules compared to values previously reported and present new results for CH{sub 3} and HNCO. Several physical and chemical models are considered. The favored model involves a nearly edge-on disk around a massive star. Radiation from dust in the inner disk passes through the disk atmosphere, where large molecular column densities can produce the observed absorption line spectrum.

    15. Results of a search for faint galaxies in voids.

      NASA Astrophysics Data System (ADS)

      Kuhn, B.; Hopp, U.; Elsaesser, H.

      1997-02-01

      We present the results of a search for intrinsically faint galaxies towards three regions with known voids and the Hercules supercluster. The intention was to identify galaxies of low luminosity in order to find possibly a galaxy population in the voids. Within these selected fields we increased the range of observations in comparison with the recent large field surveys which revealed the non-uniform spatial distribution of galaxies. The limiting magnitude was raised by about 5mag, the limiting surface brightness by 2mag/sq.arcsec, and the limiting diameter reduced to less than 1/3. The individual observational data of our sample are published in the previous PaperI (Hopp et al. 1995) which describes our search strategy and contains B and R magnitudes, apparent diameters, redshifts and galaxy types of about 200 newly identified objects. Their luminosity distribution demonstrates a relatively high percentage of dwarfish galaxies. As the essential result of our survey we have to point out that no clear indication of a void-population was found. The majority of our objects lie outside voids in regions where the already known galaxies are concentrated. Some are located in the middle or near the edges of voids. They appear to be rather isolated, their distances to the nearest neighbour are quite large. Only few of our objects seem to be real void galaxies. Even in the three nearest and rather well defined voids we do not find any hitherto unknown galaxy.

    16. The population of tiny near-Earth objects observed by NEOWISE

      SciTech Connect

      Mainzer, A.; Bauer, J.; Masiero, J.; Nugent, C. R.; Stevenson, R.; Clyne, E.; Cukrov, G.; Grav, T.; Cutri, R. M.; Masci, F.; Wright, E.

      2014-04-01

      Only a very small fraction of the asteroid population at size scales comparable to the object that exploded over Chelyabinsk, Russia has been discovered to date, and physical properties are poorly characterized. We present previously unreported detections of 105 close approaching near-Earth objects (NEOs) by the Wide-field Infrared Survey Explorer (WISE) mission's NEOWISE project. These infrared observations constrain physical properties such as diameter and albedo for these objects, many of which are found to be smaller than 100 m. Because these objects are intrinsically faint, they were detected by WISE during very close approaches to the Earth, often at large apparent on-sky velocities. We observe a trend of increasing albedo with decreasing size, but as this sample of NEOs was discovered by visible light surveys, it is likely that selection biases against finding small, dark NEOs influence this finding.

    17. Complex organic matter in space: about the chemical composition of carriers of the Unidentified Infrared Bands (UIBs) and protoplanetary emission spectra recorded from certain astrophysical objects.

      PubMed

      Cataldo, Franco; Keheyan, Yeghis; Heymann, Dieter

      2004-02-01

      In this communication we present the basic concept that the pure PAHs (Polycyclic Aromatic Hydrocarbons) can be considered only the ideal carriers of the UIBs (Unidentified Infrared Bands), the emission spectra coming from a large variety of astronomical objects. Instead we have proposed that the carriers of UIBs and of protoplanetary nebulae (PPNe) emission spectra are much more complex molecular mixtures possessing also complex chemical structures comparable to certain petroleum fractions obtained from the petroleum refining processes. The demonstration of our proposal is based on the comparison between the emission spectra recorded from the protoplanetary nebulae (PPNe) IRAS 22272+ 5435 and the infrared absorption spectra of certain 'heavy' petroleum fractions. It is shown that the best match with the reference spectrum is achieved by highly aromatic petroleum fractions. It is shown that the selected petroleum fractions used in the present study are able to match the band pattern of anthracite coal. Coal has been proposed previously as a model for the PPNe and UIBs but presents some drawbacks which could be overcome by adopting the petroleum fractions as model for PPNe and UIBs in place of coal. A brief discussion on the formation of the petroleum-like fractions in PPNe objects is included. PMID:14979641

    18. Is the faint young Sun paradox solved?

      NASA Astrophysics Data System (ADS)

      Wolf, E. T.; Toon, O. B.

      2013-12-01

      How did the early Earth remain warm despite weak solar luminosity? The faint young Sun paradox has stubbornly resisted a self-consistent solution since it was first introduced by Sagan and Mullen [1] over four decades ago. However, recent revisions to expected paleo-ocean temperatures [2, 3] along with new results from three-dimensional climate models [4] may allow this long standing problem to be finally put to rest. Here we use a modified version of the Community Atmosphere Model version 3 from the National Center for Atmospheric Research to study early climate. We find that resolving the faint young Sun paradox becomes less problematic when viewing a full representation of the climate system. For the late Archean climate (80% solar constant), relatively modest amounts of CO2 (≤0.02 bar) and CH4 (0.001 bar) yield surface temperatures equal to the present day with no other alterations to climate. Cooler climates with large ice caps but with temperate tropical regions can be supported with considerably smaller greenhouse gas burdens. The incorporation of systematic climate system elements expected for the Archean such as fewer cloud condensation nuclei (CCN) [5], reduced land albedos [5], and an increased atmospheric inventory of N2 [6], can provide a combined 10 to 20 K of additional surface warming given reasonable assumptions. With the inclusion of 0.001 bar of CH4, 2 PAL of N2, reduced land albedos, and reduced CCN, present day mean surface temperatures can be maintained for the earliest Archean (75% solar constant) with only ~0.01 bar of CO2. However, lower requirements for atmospheric CO2 may imply that photochemical hazes were frequent during the Archean. [1] Sagan, C., & Mullen, G. Science 177, 52 (1972) [2] Hren, M.T., Tice, M.M., & Chamberlin, C.P. Nature 462, 205 (2009) [3] Blake. R.E., Chang, S.J., & Lepland, A. Nature 464, 1029 (2010) [4] Wolf, E.T., & Toon, O.B. Astrobiology 13(7), 1 (2013) [5] Rosing, M.T., Bird, D.K., Sleep, N.H., & Bjerrum, C

    19. Joint US-Japan Observations with the Infrared Space Observatory (ISO): Deep Surveys and Observations of High-Z Objects

      NASA Technical Reports Server (NTRS)

      Sanders, David B.

      1997-01-01

      Several important milestones were passed during the past year of our ISO observing program: (1) Our first ISO data were successfully obtained. ISOCAM data were taken for our primary deep field target in the 'Lockman Hole'. Thirteen hours of integration (taken over 4 contiguous orbits) were obtained in the LW2 filter of a 3 ft x 3 ft region centered on the position of minimum HI column density in the Lockman Hole. The data were obtained in microscanning mode. This is the deepest integration attempted to date (by almost a factor of 4 in time) with ISOCAM. (2) The deep survey data obtained for the Lockman Hole were received by the Japanese P.I. (Yoshi Taniguchi) in early December, 1996 (following release of the improved pipeline formatted data from Vilspa), and a copy was forwarded to Hawaii shortly thereafter. These data were processed independently by the Japan and Hawaii groups during the latter part of December 1996, and early January, 1997. The Hawaii group made use of the U.S. ISO data center at IPAC/Caltech in Pasadena to carry out their data reduction, while the Japanese group used a copy of the ISOCAM data analysis package made available to them through an agreement with the head of the ISOCAM team, Catherine Cesarsky. (3) Results of our LW2 Deep Survey in the Lockman Hole were first reported at the ISO Workshop "Taking ISO to the Limits: Exploring the Faintest Sources in the Infrared" held at the ISO Science Operations Center in Villafranca, Spain (VILSPA) on 3-4 February, 1997. Yoshi Taniguchi gave an invited presentation summarizing the results of the U.S.-Japan team, and Dave Sanders gave an invited talk summarizing the results of the Workshop at the conclusion of the two day meeting. The text of the talks by Taniguchi and Sanders are included in the printed Workshop Proceedings, and are published in full on the Web. By several independent accounts, the U.S.-Japan Deep Survey results were one of the highlights of the Workshop; these data showed

    20. Planetcam: A Visible And Near Infrared Lucky-imaging Camera To Study Planetary Atmospheres And Solar System Objects

      NASA Astrophysics Data System (ADS)

      Sanchez-Lavega, Agustin; Rojas, J.; Hueso, R.; Perez-Hoyos, S.; de Bilbao, L.; Murga, G.; Ariño, J.; Mendikoa, I.

      2012-10-01

      PlanetCam is a two-channel fast-acquisition and low-noise camera designed for a multispectral study of the atmospheres of the planets (Venus, Mars, Jupiter, Saturn, Uranus and Neptune) and the satellite Titan at high temporal and spatial resolutions simultaneously invisible (0.4-1 μm) and NIR (1-2.5 μm) channels. This is accomplished by means of a dichroic beam splitter that separates both beams directing them into two different detectors. Each detector has filter wheels corresponding to the characteristic absorption bands of each planetary atmosphere. Images are acquired and processed using the “lucky imaging” technique in which several thousand images of the same object are obtained in a short time interval, coregistered and ordered in terms of image quality to reconstruct a high-resolution ideally diffraction limited image of the object. Those images will be also calibrated in terms of intensity and absolute reflectivity. The camera will be tested at the 50.2 cm telescope of the Aula EspaZio Gela (Bilbao) and then commissioned at the 1.05 m at Pic-duMidi Observatory (Franca) and at the 1.23 m telescope at Calar Alto Observatory in Spain. Among the initially planned research targets are: (1) The vertical structure of the clouds and hazes in the planets and their scales of variability; (2) The meteorology, dynamics and global winds and their scales of variability in the planets. PlanetCam is also expected to perform studies of other Solar System and astrophysical objects. Acknowledgments: This work was supported by the Spanish MICIIN project AYA2009-10701 with FEDER funds, by Grupos Gobierno Vasco IT-464-07 and by Universidad País Vasco UPV/EHU through program UFI11/55.

    1. Accurate shear measurement with faint sources

      SciTech Connect

      Zhang, Jun; Foucaud, Sebastien; Luo, Wentao E-mail: walt@shao.ac.cn

      2015-01-01

      For cosmic shear to become an accurate cosmological probe, systematic errors in the shear measurement method must be unambiguously identified and corrected for. Previous work of this series has demonstrated that cosmic shears can be measured accurately in Fourier space in the presence of background noise and finite pixel size, without assumptions on the morphologies of galaxy and PSF. The remaining major source of error is source Poisson noise, due to the finiteness of source photon number. This problem is particularly important for faint galaxies in space-based weak lensing measurements, and for ground-based images of short exposure times. In this work, we propose a simple and rigorous way of removing the shear bias from the source Poisson noise. Our noise treatment can be generalized for images made of multiple exposures through MultiDrizzle. This is demonstrated with the SDSS and COSMOS/ACS data. With a large ensemble of mock galaxy images of unrestricted morphologies, we show that our shear measurement method can achieve sub-percent level accuracy even for images of signal-to-noise ratio less than 5 in general, making it the most promising technique for cosmic shear measurement in the ongoing and upcoming large scale galaxy surveys.

    2. Simulation of laser detection and ranging (LADAR) and forward-looking infrared (FLIR) data for autonomous tracking of airborne objects

      NASA Astrophysics Data System (ADS)

      Powell, Gavin; Markham, Keith C.; Marshall, David

      2000-06-01

      This paper presents the results of an investigation leading into an implementation of FLIR and LADAR data simulation for use in a multi sensor data fusion automated target recognition system. At present the main areas of application are in military environments but systems can easily be adapted to other areas such as security applications, robotics and autonomous cars. Recent developments have been away from traditional sensor modeling and toward modeling of features that are external to the system, such as atmosphere and part occlusion, to create a more realistic and rounded system. We have implemented such techniques and introduced a means of inserting these models into a highly detailed scene model to provide a rich data set for later processing. From our study and implementation we are able to embed sensor model components into a commercial graphics and animation package, along with object and terrain models, which can be easily used to create a more realistic sequence of images.

    3. The Chandra Deep Survey of the Hubble Deep Field-North Area. II. Results from the Caltech Faint Field Galaxy Redshift Survey Area

      NASA Astrophysics Data System (ADS)

      Hornschemeier, A. E.; Brandt, W. N.; Garmire, G. P.; Schneider, D. P.; Barger, A. J.; Broos, P. S.; Cowie, L. L.; Townsley, L. K.; Bautz, M. W.; Burrows, D. N.; Chartas, G.; Feigelson, E. D.; Griffiths, R. E.; Lumb, D.; Nousek, J. A.; Ramsey, L. W.; Sargent, W. L. W.

      2001-06-01

      A deep X-ray survey of the Hubble Deep Field-North (HDF-N) and its environs is performed using data collected by the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-Ray Observatory. Currently a 221.9 ks exposure is available, the deepest ever presented, and here we give results on X-ray sources located in the 8.6‧×8.7‧ area covered by the Caltech Faint Field Galaxy Redshift Survey (the ``Caltech area''). This area has (1) deep photometric coverage in several optical and near-infrared bands; (2) extensive coverage at radio, submillimeter, and mid-infrared wavelengths; and (3) some of the deepest and most complete spectroscopic coverage ever obtained. It is also where the X-ray data have the greatest sensitivity; the minimum detectable fluxes in the 0.5-2 keV (soft) and 2-8 keV (hard) bands are ~1.3×10-16 and ~6.5×10-16 ergs cm-2 s-1, respectively. More than ~80% of the extragalactic X-ray background in the hard band is resolved. The 82 Chandra sources detected in the Caltech area are correlated with more than 25 multiwavelength source catalogs, and the results of these correlations as well as spectroscopic follow-up results obtained with the Keck and Hobby-Eberly Telescopes are presented. All but nine of the Chandra sources are detected optically with R<~26.5. Redshifts are available for 39% of the Chandra sources, including 96% of the sources with R<23 the redshift range is 0.1-3.5, with most sources having z<1.5. Eight of the X-ray sources are located in the HDF-N itself, including two not previously reported. A population of X-ray faint, optically bright, nearby galaxies emerges at soft-band fluxes of <~3×10-16 ergs cm-2 s-1. Our multiwavelength correlations have set the tightest constraints to date on the X-ray emission properties of μJy radio sources, mid-infrared sources detected by the Infrared Space Observatory (ISO), and very red (R-Ks>5.0) objects. A total of 16 of the 67 1.4 GHz μJy sources in the Caltech area are detected in the

    4. Near-infrared multiwavelength imaging polarimetry of the low-mass proto-stellar object HL Tauri

      NASA Astrophysics Data System (ADS)

      Murakawa, K.; Oya, S.; Pyo, T.-S.; Ishii, M.

      2008-12-01

      We present the {JHK}-band high-resolution polarimetric images of the low-mass proto-stellar object HL Tau using the adaptive optics-equipped CIAO instrument on the Subaru telescope. Our polarization images show a butterfly-shaped polarization disk with an ˜0.9 arcsec × 3.0 arcsec extension. In the nebula, where polarization vectors are centro-symmetrically aligned, the polarization is as high as PJ ˜30%, P_H˜42%, and PK ˜55%. On the other hand, low polarizations of P<3% in the J, H, and K bands and a low color excess ratio of EJ-H/EH-K=1.1 compared to the standard cloud value of 1.75 are detected towards the central star. We estimated the upper limit of the grain sizes a_max to be 0.4 μm in the nebula and ⪆0.7 μm in the line of sight towards the central star. Our high-resolution polarimetric data, which spatially resolves the polarization disk, provides us with important information about grain growth in the region close to the central star.

    5. VY Monocerotis and the IC 446 region - Far-infrared and submillimeter images of a massive young stellar object and its environment

      SciTech Connect

      Casey, S.C.; Harper, D.A. Yerkes Observatory, Williams Bay, WI )

      1990-10-01

      The reflection nebulae IC 446 has been mapped in an 8 x 8-arcmin area at 100, 160, and 370 microns using 32-channel bolometer-array detectors on the 0.9-m telescope of the NASA Kuiper Airborne Observatory and the 3-m telescope of the NASA Infrared Telescope Facility. These data have been combined with IRAS profiles at 12, 25, 60, and 100 microns to investigate the morphology and energetics of the region. The FIR through submm emission in the neighborhood of IC 446 is composed of three components: a compact point source associated with the young stellar object VY Mon, warm extended emission associated with dust in the reflection nebula IC 446, and cold extended emission associated with a dark absorption nebula or globule. 69 refs.

    6. VY Monocerotis and the IC 446 region - Far-infrared and submillimeter images of a massive young stellar object and its environment

      NASA Technical Reports Server (NTRS)

      Casey, S. C.; Harper, D. A.

      1990-01-01

      The reflection nebulae IC 446 has been mapped in an 8 x 8-arcmin area at 100, 160, and 370 microns using 32-channel bolometer-array detectors on the 0.9-m telescope of the NASA Kuiper Airborne Observatory and the 3-m telescope of the NASA Infrared Telescope Facility. These data have been combined with IRAS profiles at 12, 25, 60, and 100 microns to investigate the morphology and energetics of the region. The FIR through submm emission in the neighborhood of IC 446 is composed of three components: a compact point source associated with the young stellar object VY Mon, warm extended emission associated with dust in the reflection nebula IC 446, and cold extended emission associated with a dark absorption nebula or globule.

    7. Star formation in infrared bright and infrared faint starburst interacting galaxies

      NASA Technical Reports Server (NTRS)

      Lamb, Susan A.; Bushouse, Howard A.; Towns, John W.

      1990-01-01

      Short wavelength IUE spectra of Arp 248b and UGC 8315N are combined with optical spectra and interpreted using a combination of spectrum synthesis and spectral diagnostics to place constraints on the massive star populations of the central regions of these galaxies and to deduce information about the star formation histories in the last 10(exp 8) years. The authors find that both galaxies have substantial fractions of their optical light coming from massive stars and that Arp 248b may be dominated in the UV by WR stars. The UV spectra are dominated by radiation from evolved massive stars and the authors place and age on the burst in Arp 248b of a few tens of millions of years.

    8. Conditions for the use of infrared camera diagnostics in energy auditing of the objects exposed to open air space at isothermal sky

      NASA Astrophysics Data System (ADS)

      Kruczek, Tadeusz

      2015-03-01

      Convective and radiation heat transfer take place between various objects placed in open air space and their surroundings. These phenomena bring about heat losses from pipelines, building walls, roofs and other objects. One of the main tasks in energy auditing is the reduction of excessive heat losses. In the case of a low sky temperature, the radiation heat exchange is very intensive and the temperature of the top part of the horizontal pipelines or walls is lower than the temperature of their bottom parts. Quite often this temperature is also lower than the temperature of the surrounding atmospheric air. In the case of overhead heat pipelines placed in open air space, it is the ground and sky that constitute the surroundings. The aforementioned elements of surroundings usually have different values of temperature. Thus, these circumstances bring about difficulties during infrared inspections because only one ambient temperature which represents radiation of all surrounding elements must be known during the thermovision measurements. This work is aimed at the development of a method for determination of an equivalent ambient temperature representing the thermal radiation of the surrounding elements of the object under consideration placed in open air space, which could be applied at a fairly uniform temperature of the sky during the thermovision measurements as well as for the calculation of radiative heat losses.

    9. Faint solar radio structures from decametric observations

      NASA Astrophysics Data System (ADS)

      Briand, C.; Zaslavsky, A.; Maksimovic, M.; Zarka, P.; Lecacheux, A.; Rucker, H. O.; Konovalenko, A. A.; Abranin, E. P.; Dorovsky, V. V.; Stanislavsky, A. A.; Melnik, V. N.

      2008-10-01

      Aims: Decameter radio observations of the solar corona reveal the presence of numerous faint frequency drifting emissions, similar to “solar S bursts” which are reported in the literature. We present a statistical analysis of the characteristics of these emissions and propose a mechanism to excite the Langmuir waves thought to be at the origin of these emissions. Methods: The observations were performed between 1998 and 2002 with the Digital Spectro Polarimeter (DSP) receivers operated at the UTR-2 and Nançay decameter radio telescopes in the frequency range 15-30 MHz. Our theoretical explanation is based on Vlasov-Ampère simulations. Results: Based on the frequency drift rate, three populations of structures can be identified. The largest population presents an average negative frequency drift of -0.9 MHz s-1 and a lifetime up to 11 s (median value of 2.72 s). A second population shows a very small frequency drift of -0.1 MHz s-1 and a short lifetime of about 1 s. The third population presents an average positive frequency drift of +0.95 MHz s-1 and a lifetime of up to 3 s. Also, the frequency drift as a function of frequency is consistent with the former results, which present results in higher frequency range. No specific relationship was found between the occurrence of these emissions and the solar cycle or presence of flares. Assuming that these emissions are produced by “electron clouds” propagating the solar corona, we deduce electron velocities of about 3-5 times the electron thermal velocity. As previously shown, a localized, time-dependent modulation of the electron distribution function (heating) leads to low velocity electron clouds (consistent with observations), which, in turn, can generate Langmuir waves and electromagnetic signals by nonlinear processes.

    10. Clouds and the Faint Young Sun Paradox

      NASA Astrophysics Data System (ADS)

      Goldblatt, C.; Zahnle, K. J.

      2011-03-01

      We investigate the role which clouds could play in resolving the Faint Young Sun Paradox (FYSP). Lower solar luminosity in the past means that less energy was absorbed on Earth (a forcing of -50 W m-2 during the late Archean), but geological evidence points to the Earth having been at least as warm as it is today, with only very occasional glaciations. We perform radiative calculations on a single global mean atmospheric column. We select a nominal set of three layered, randomly overlapping clouds, which are both consistent with observed cloud climatologies and reproduced the observed global mean energy budget of Earth. By varying the fraction, thickness, height and particle size of these clouds we conduct a wide exploration of how changed clouds could affect climate, thus constraining how clouds could contribute to resolving the FYSP. Low clouds reflect sunlight but have little greenhouse effect. Removing them entirely gives a forcing of +25 W m-2 whilst more modest reduction in their efficacy gives a forcing of +10 to +15 W m-2. For high clouds, the greenhouse effect dominates. It is possible to generate +50 W m-2 forcing from enhancing these, but this requires making them 3.5 times thicker and 14 K colder than the standard high cloud in our nominal set and expanding their coverage to 100% of the sky. Such changes are not credible. More plausible changes would generate no more than +15 W m-2 forcing. Thus neither fewer low clouds nor more high clouds can provide enough forcing to resolve the FYSP. Decreased surface albedo can contribute no more than +5 W m-2 forcing. Some models which have been applied to the FYSP do not include clouds at all. These overestimate the forcing due to increased CO2 by 20 to 25% when pCO2 is 0.01 to 0.1 bar.

    11. NASA Researches the 'FaINT' Side of Sonic Booms

      NASA Video Gallery

      As the latest in a continuing progression of NASA supersonics research projects aimed at reducing or mitigating the effect of sonic booms, the Farfield Investigation of No Boom Threshold, or FaINT,...

    12. Faint Blue Galaxies and the Epoch of Dwarf Galaxy Formation

      NASA Astrophysics Data System (ADS)

      Babul, Arif; Ferguson, Henry C.

      1996-02-01

      Several independent lines of reasoning, both theoretical and observational, suggest that the very faint (B ≳ 24) galaxies seen in deep images of the sky are small low-mass galaxies that experienced a short starburst at redshifts 0.5 ≲ z ≲ 1 and have since faded into low-luminosity, low surface brightness (LSB) objects. We examine this hypothesis in detail in order to determine whether a model incorporating such dwarfs can account for the observed wavelength-dependent number counts, as well as redshift, color, and size distributions. Low-mass galaxies generically arise in large numbers in hierarchical clustering scenarios with realistic initial conditions. Generally, these galaxies are expected to form at high redshifts. Babul & Rees have argued that the formation epoch of these galaxies is, in fact, delayed until z ≲ 1 due to the photoionization of the gas by the metagalactic UV radiation at high redshifts. We combine these two elements, along with simple heuristic assumptions regarding star formation histories and efficiency, to construct our bursting dwarf model. The slope and the normalization of the mass function of the dwarf galaxies are derived from the initial conditions and are not adjusted to fit the data. We further augment the model with a phenomenological prescription for the formation and evolution of the locally observed population of galaxies (E, S0, Sab, Sbc, and Sdm types). We use spectral synthesis and Monte Carlo methods to generate realistic model galaxy catalogs for comparison with observations. We find that for reasonable choices of the star formation histories for the dwarf galaxies, the model results are in very good agreement with the results of the deep galaxy surveys. Such a dwarf-dominated model is also qualitatively supported by recent studies of faint galaxy gravitational lensing and clustering, by galaxy size distributions measured with the Hubble Space Telescope, and by the evidence for very modest evolution in regular galaxy

    13. Configurable slit-mask unit of the Multi-Object Spectrometer for Infra-Red Exploration for the Keck telescope: integration and tests

      NASA Astrophysics Data System (ADS)

      Spanoudakis, Peter; Giriens, Laurent; Henein, Simon; Lisowski, Leszek; O'Hare, Aidan; Onillon, Emmanuel; Schwab, Philippe; Theurillat, Patrick

      2008-07-01

      A Configurable Slit Unit (CSU) has been developed for the Multi-Object Spectrometer for Infra-Red Exploration (MOSFIRE) instrument to be installed on the Keck 1 Telescope on Mauna Kea, Hawaii. MOSFIRE will provide NIR multi-object spectroscopy over a field of view of 6.1' x 6.1'. The reconfigurable mask allows the formation of 46 optical slits in a 267 x 267 mm2 field of view. The mechanism is an evolution of a former prototype designed by CSEM and qualified for the European Space Agency (ESA) as a candidate for the slit mask on NIRSpec for the James Webb Space Telescope (JWST). The CSU is designed to simultaneously displace masking bars across the field-of-view (FOV) to mask unwanted light. A set of 46 bar pairs are used to form the MOSFIRE focal plane mask. The sides of the bars are convoluted so that light is prevented from passing between adjacent bars. The slit length is fixed (5.1 mm) but the width is variable down to 200 μm with a slit positioning accuracy of +/- 18 μm. A two-bar prototype mechanism was designed, manufactured and cryogenically tested to validate the modifications from the JWST prototype. The working principle of the mechanism is based on an improved "inch-worm" stepping motion of 92 masking bars forming the optical mask. Original voice coil actuators are used to drive the various clutches. The design makes significant use of flexure structures.

    14. Star formation and the interstellar medium in nearby tidal streams (SAINTS): Spitzer mid-infrared spectroscopy and imaging of intergalactic star-forming objects

      SciTech Connect

      Higdon, S. J. U.; Higdon, J. L.; Smith, B. J.; Hancock, M.

      2014-06-01

      A spectroscopic analysis of 10 intergalactic star-forming objects (ISFOs) and a photometric analysis of 67 ISFOs in a sample of 14 interacting systems is presented. The majority of the ISFOs have relative polycyclic aromatic hydrocarbon (PAH) band strengths similar to those of nearby spiral and starburst galaxies. In contrast to what is observed in blue compact dwarfs (BCDs) and local giant H II regions in the Milky Way (NGC 3603) and the Magellanic Clouds (30 Doradus and N 66), the relative PAH band strengths in ISFOs correspond to models with a significant PAH ion fraction (<50%) and bright emission from large PAHs (∼100 carbon atoms). The [Ne III]/[Ne II] and [S IV]/[S III] line flux ratios indicate moderate levels of excitation with an interstellar radiation field that is harder than the majority of the Spitzer Infrared Nearby Galaxies Survey and starburst galaxies, but softer than BCDs and local giant H II regions. The ISFO neon line flux ratios are consistent with a burst of star formation ≲6 million years ago. Most of the ISFOs have ∼10{sup 6} M {sub ☉} of warm H{sub 2} with a likely origin in photo-dissociation regions (PDRs). Infrared Array Camera photometry shows the ISFOs to be bright at 8 μm, with one-third having [4.5] – [8.0] > 3.7, i.e., enhanced non-stellar emission, most likely due to PAHs, relative to normal spirals, dwarf irregulars, and BCD galaxies. The relative strength of the 8 μm emission compared to that at 3.6 μm or 24 μm separates ISFOs from dwarf galaxies in Spitzer two-color diagrams. The infrared power in two-thirds of the ISFOs is dominated by emission from grains in a diffuse interstellar medium. One in six ISFOs have significant emission from PDRs, contributing ∼30%-60% of the total power. ISFOs are young knots of intense star formation.

    15. MEASURING THE UNDETECTABLE: PROPER MOTIONS AND PARALLAXES OF VERY FAINT SOURCES

      SciTech Connect

      Lang, Dustin; Hogg, David W.; Jester, Sebastian; Rix, Hans-Walter

      2009-05-15

      The near future of astrophysics involves many large solid-angle, multi-epoch, multiband imaging surveys. These surveys will, at their faint limits, have data on a large number of sources that are too faint to be detected at any individual epoch. Here, we show that it is possible to measure in multi-epoch data not only the fluxes and positions, but also the parallaxes and proper motions of sources that are too faint to be detected at any individual epoch. The method involves fitting a model of a moving point source simultaneously to all imaging, taking account of the noise and point-spread function (PSF) in each image. By this method it is possible to measure the proper motion of a point source with an uncertainty close to the minimum possible uncertainty given the information in the data, which is limited by the PSF, the distribution of observation times (epochs), and the total signal-to-noise in the combined data. We demonstrate our technique on multi-epoch Sloan Digital Sky Survey (SDSS) imaging of the SDSS Southern Stripe (SDSSSS). We show that with our new technique we can use proper motions to distinguish very red brown dwarfs from very high-redshift quasars in these SDSS data, for objects that are inaccessible to traditional techniques, and with better fidelity than by multiband imaging alone. We rediscover all 10 known brown dwarfs in our sample and present nine new candidate brown dwarfs, identified on the basis of significant proper motion.

    16. A Peculiar Faint Satellite in the Remote Outer Halo of M31

      NASA Astrophysics Data System (ADS)

      Mackey, A. D.; Huxor, A. P.; Martin, N. F.; Ferguson, A. M. N.; Dotter, A.; McConnachie, A. W.; Ibata, R. A.; Irwin, M. J.; Lewis, G. F.; Sakari, C. M.; Tanvir, N. R.; Venn, K. A.

      2013-06-01

      We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age >~ 10 Gyr and [Fe/H] lsim -2.3. Our inferred distance modulus (m - M)0 = 24.57 ± 0.11 confirms that PAndAS-48 is most likely a remote M31 satellite with a three-dimensional galactocentric radius of 149^{+19}_{-8} kpc. We observe an apparent spread in color on the upper red giant branch that is larger than the photometric uncertainties should allow, and briefly explore the implications of this. Structurally, PAndAS-48 is diffuse, faint, and moderately flattened, with a half-light radius r_h=26^{+4}_{-3} pc, integrated luminosity MV = -4.8 ± 0.5, and ellipticity \\epsilon =0.30^{+0.08}_{-0.15}. On the size-luminosity plane it falls between the extended globular clusters seen in several nearby galaxies and the recently discovered faint dwarf satellites of the Milky Way; however, its characteristics do not allow us to unambiguously classify it as either type of system. If PAndAS-48 is a globular cluster then it is among the most elliptical, isolated, and metal-poor of any seen in the Local Group, extended or otherwise. Conversely, while its properties are generally consistent with those observed for the faint Milky Way dwarfs, it would be a factor of ~2-3 smaller in spatial extent than any known counterpart of comparable luminosity. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO 12515.

    17. A PECULIAR FAINT SATELLITE IN THE REMOTE OUTER HALO OF M31

      SciTech Connect

      Mackey, A. D.; Dotter, A.; Huxor, A. P.; Martin, N. F.; Ibata, R. A.; Ferguson, A. M. N.; McConnachie, A. W.; Irwin, M. J.; Lewis, G. F.; Sakari, C. M.; Venn, K. A.; Tanvir, N. R.

      2013-06-20

      We present Hubble Space Telescope imaging of a newly discovered faint stellar system, PAndAS-48, in the outskirts of the M31 halo. Our photometry reveals this object to be comprised of an ancient and very metal-poor stellar population with age {approx}> 10 Gyr and [Fe/H] {approx}< -2.3. Our inferred distance modulus (m - M){sub 0} = 24.57 {+-} 0.11 confirms that PAndAS-48 is most likely a remote M31 satellite with a three-dimensional galactocentric radius of 149{sup +19}{sub -8} kpc. We observe an apparent spread in color on the upper red giant branch that is larger than the photometric uncertainties should allow, and briefly explore the implications of this. Structurally, PAndAS-48 is diffuse, faint, and moderately flattened, with a half-light radius r{sub h}=26{sup +4}{sub -3} pc, integrated luminosity M{sub V} = -4.8 {+-} 0.5, and ellipticity {epsilon}=0.30{sup +0.08}{sub -0.15}. On the size-luminosity plane it falls between the extended globular clusters seen in several nearby galaxies and the recently discovered faint dwarf satellites of the Milky Way; however, its characteristics do not allow us to unambiguously classify it as either type of system. If PAndAS-48 is a globular cluster then it is among the most elliptical, isolated, and metal-poor of any seen in the Local Group, extended or otherwise. Conversely, while its properties are generally consistent with those observed for the faint Milky Way dwarfs, it would be a factor of {approx}2-3 smaller in spatial extent than any known counterpart of comparable luminosity.

    18. The faint radio source population at 15.7 GHz - II. Multi-wavelength properties

      NASA Astrophysics Data System (ADS)

      Whittam, I. H.; Riley, J. M.; Green, D. A.; Jarvis, M. J.; Vaccari, M.

      2015-11-01

      A complete, flux density limited sample of 96 faint (>0.5 mJy) radio sources is selected from the 10C survey at 15.7 GHz in the Lockman Hole. We have matched this sample to a range of multi-wavelength catalogues, including Spitzer Extragalactic Representative Volume Survey, Spitzer Wide-area Infrared Extragalactic survey, United Kingdom Infrared Telescope Infrared Deep Sky Survey and optical data; multi-wavelength counterparts are found for 80 of the 96 sources and spectroscopic redshifts are available for 24 sources. Photometric redshifts are estimated for the sources with multi-wavelength data available; the median redshift of the sample is 0.91 with an interquartile range of 0.84. Radio-to-optical ratios show that at least 94 per cent of the sample are radio loud, indicating that the 10C sample is dominated by radio galaxies. This is in contrast to samples selected at lower frequencies, where radio-quiet AGN and star-forming galaxies are present in significant numbers at these flux density levels. All six radio-quiet sources have rising radio spectra, suggesting that they are dominated by AGN emission. These results confirm the conclusions of Paper I that the faint, flat-spectrum sources which are found to dominate the 10C sample below ˜1 mJy are the cores of radio galaxies. The properties of the 10C sample are compared to the Square Kilometre Array Design Studies Simulated Skies; a population of low-redshift star-forming galaxies predicted by the simulation is not found in the observed sample.

    19. A Search for Faint, Diffuse Halo Emission in Edge-On Galaxies with Spitzer/IRAC

      NASA Astrophysics Data System (ADS)

      Ashby, Matthew; Arendt, R. G.; Pipher, J. L.; Forrest, W. J.; Marengo, M.; Barmby, P.; Willner, S. P.; Stauffer, J. R.; Fazio, G. G.

      2006-12-01

      We present deep infrared mosaics of the nearby edge-on spiral galaxies NGC 891, 4244, 4565, and 5907. These data were acquired at 3.6, 4.5, 5.8, and 8.0 microns using the Infrared Array Camera aboard Spitzer as part of GTO program number 3. This effort is designed to detect the putative faint, diffuse emission from halos and thick disks of spiral galaxies in the near-mid infrared under the thermally stable, low-background conditions of space. These conditions in combination with the advantageous viewing angles presented by these well-known edge-on spirals provide arguably the best opportunity to characterize the halo/thick disk components of such galaxies in the infrared. In this contribution we describe our observations, data reduction techniques, corrections for artifacts in the data, and the modeling approach we applied to analyze this unique dataset. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

    20. FAINT SUBMILLIMETER GALAXY COUNTS AT 450 {mu}m

      SciTech Connect

      Chen, Chian-Chou; Cowie, Lennox L.; Barger, Amy J.; Casey, Caitlin M.; Lee, Nicholas; Sanders, David B.; Williams, Jonathan P.; Wang, Wei-Hao

      2013-01-10

      We present the results of SCUBA-2 observations at 450 {mu}m and 850 {mu}m of the field lensed by the massive cluster A370. With a total survey area >100 arcmin{sup 2} and 1{sigma} sensitivities of 3.92 and 0.82 mJy beam{sup -1} at 450 and 850 {mu}m, respectively, we find a secure sample of 20 sources at 450 {mu}m and 26 sources at 850 {mu}m with a signal-to-noise ratio (S/N) > 4. Using the latest lensing model of A370 and Monte Carlo simulations, we derive the number counts at both wavelengths. The 450 {mu}m number counts probe a factor of four deeper than the counts recently obtained from the Herschel Space Telescope at similar wavelengths, and we estimate that {approx}47%-61% of the 450 {mu}m extragalactic background light resolved into individual sources with 450 {mu}m fluxes greater than 4.5 mJy. The faint 450 {mu}m sources in the 4{sigma} sample have positional accuracies of 3 arcsec, while brighter sources (S/N >6{sigma}) are good to 1.4 arcsec. Using a deep radio map (1{sigma} {approx} 6 {mu}Jy) we find that the percentage of submillimeter sources having secure radio counterparts is 85% for 450 {mu}m sources with intrinsic fluxes >6 mJy and 67% for 850 {mu}m sources with intrinsic fluxes >4 mJy. We also find that 67% of the >4{sigma} 450 {mu}m sources are detected at 850 {mu}m, while the recovery rate at 450 {mu}m of >4{sigma} 850 {mu}m sources is 54%. Combined with the source redshifts estimated using millimetric flux ratios, the recovered rate is consistent with the scenario where both 450 {mu}m and 20 cm emission preferentially select lower redshift dusty sources, while 850 {mu}m emission traces a higher fraction of dusty sources at higher redshifts. We identify potential counterparts in various wavelengths from X-ray to mid-infrared and measure the multiwavelength photometry, which we then use to analyze the characteristics of the sources. We find three X-ray counterparts to our robust submillimeter sample (S/N > 5), giving an active galactic nucleus

    1. The nature of faint emission-line galaxies

      NASA Technical Reports Server (NTRS)

      Smetanka, John J.

      1993-01-01

      One of the results of faint galaxy redshift surveys is the increased fraction of galaxies which have strong emission-line spectra. These faint surveys find that roughly 50 percent of the galaxies have an equivalent width of (OII), W sub 3727, greater than 20 A while this fraction is less than 20 percent in the DARS survey. This has been interpreted as evidence for strong evolution in the galaxy population at redshifts less than 0.5. In order to further investigate the properties of the galaxies in faint redshift surveys, two important factors must be addressed. The first is the observed correlation between color, luminosity, and W sub 3727. There is a correlation between color and the strength of emission lines, bluer galaxies having stronger emission features, as evident for Markarian galaxies and for galaxies in Kennicutt's spectrophotometric atlas. This correlation also applies galaxies in faint redshift surveys. In addition, low luminosity galaxies have a larger average W sub 3727 (and bluer colors) than higher luminosity galaxies. This is illustrated for Kennicutt's low z late-type galaxies, for the Durham Faint Surveys, and for galaxies in SA68. The second factor which must be incorporated into any interpretation of the faint emission galaxies is the different luminosity functions for galaxies depending on color. This is usually modeled by varying M* for different color classes (or morphological types); however, the shape of the luminosity function is different for galaxies with different colors. Low luminosity, blue galaxies have a much larger number density than low luminosity, red galaxies. Furthermore, the low luminosity end of the blue galaxy luminosity function is not well fit by a Schechter function. These two factors have been included in a very simple, no-evolution, model for the galaxy population. This model uses the luminosity functions from Shanks (1990) and spectral energy distributions (SED's) from Bruzual (1988). W sub 3727 is predicted using

    2. Chemical enrichment in Ultra-Faint Dwarf galaxies

      NASA Astrophysics Data System (ADS)

      Romano, Donatella

      2016-08-01

      Our view of the Milky Way's satellite population has radically changed after the discovery, ten years ago, of the first Ultra-Faint Dwarf galaxies (UFDs). These extremely faint, dark-matter dominated, scarcely evolved stellar systems are found in ever-increasing number in our cosmic neighbourhood and constitute a gold-mine for studies of early star formation conditions and early chemical enrichment pathways. Here we show what can be learned from the measurements of chemical abundances in UFD stars read through the lens of chemical evolution studies, point out the limitations of the classic approach, and discuss the way to go to improve the models.

    3. CONSTRAINING MASS RATIO AND EXTINCTION IN THE FU ORIONIS BINARY SYSTEM WITH INFRARED INTEGRAL FIELD SPECTROSCOPY

      SciTech Connect

      Pueyo, Laurent; Hillenbrand, Lynne; Hinkley, Sasha; Dekany, Richard; Roberts, Jenny; Vasisht, Gautam; Roberts, Lewis C. Jr.; Shao, Mike; Burruss, Rick; Cady, Eric; Oppenheimer, Ben R.; Brenner, Douglas; Zimmerman, Neil; Monnier, John D.; Crepp, Justin; Parry, Ian; Beichman, Charles; Soummer, Remi

      2012-09-20

      We report low-resolution near-infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph (IFS) Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0.''5 south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J- and H-band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low-resolution near-infrared spectrum in conjunction with 10.2 {mu}m interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, A{sub V} = 8-12, with an effective temperature of {approx}4000-6500 K. Finally, we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary system.

    4. Constraining Mass Ratio and Extinction in the FU Orionis Binary System with Infrared Integral Field Spectroscopy

      NASA Astrophysics Data System (ADS)

      Pueyo, Laurent; Hillenbrand, Lynne; Vasisht, Gautam; Oppenheimer, Ben R.; Monnier, John D.; Hinkley, Sasha; Crepp, Justin; Roberts, Lewis C., Jr.; Brenner, Douglas; Zimmerman, Neil; Parry, Ian; Beichman, Charles; Dekany, Richard; Shao, Mike; Burruss, Rick; Cady, Eric; Roberts, Jenny; Soummer, Rémi

      2012-09-01

      We report low-resolution near-infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph (IFS) Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0farcs5 south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J- and H-band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low-resolution near-infrared spectrum in conjunction with 10.2 μm interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, AV = 8-12, with an effective temperature of ~4000-6500 K. Finally, we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary system.

    5. Deriving the Extinction to Young Stellar Objects using [Fe II] Near-infrared Emission Lines: Prescriptions from GIANO High-resolution Spectra

      NASA Astrophysics Data System (ADS)

      Pecchioli, T.; Sanna, N.; Massi, F.; Oliva, E.

      2016-07-01

      The near-infrared (NIR) emission lines of Fe+ at 1.257, 1.321, and 1.644 μm share the same upper level; their ratios can then be exploited to derive the extinction to a line emitting region once the relevant spontaneous emission coefficients are known. This is commonly done, normally from low-resolution spectra, in observations of shocked gas from jets driven by Young Stellar Objects. In this paper we review this method, provide the relevant equations, and test it by analyzing high-resolution (R ∼ 50,000) NIR spectra of two young stars, namely the Herbig Be star HD 200775 and the Be star V1478 Cyg, which exhibit intense emission lines. The spectra were obtained with the new GIANO echelle spectrograph at the Telescopio Nazionale Galileo. Notably, the high-resolution spectra allowed checking the effects of overlapping telluric absorption lines. A set of various determinations of the Einstein coefficients are compared to show how much the available computations affect extinction derivation. The most recently obtained values are probably good enough to allow reddening determination within 1 visual mag of accuracy. Furthermore, we show that [Fe ii] line ratios from low-resolution pure emission-line spectra in general are likely to be in error due to the impossibility to properly account for telluric absorption lines. If low-resolution spectra are used for reddening determinations, we advice that the ratio 1.644/1.257, rather than 1.644/1.321, should be used, being less affected by the effects of telluric absorption lines.

    6. 1. Dyea Dock looking south. Note faint evenly spaced circular ...

      Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

      1. Dyea Dock looking south. Note faint evenly spaced circular dark pieces of grass up through the middle of the picture indicating posts making up the pier. Photograph made from park service cherry picker. - Dyea Dock & Association (Ruins), Skagway, Skagway, AK

    7. CONFIRMATION OF FAINT DWARF GALAXIES IN THE M81 GROUP

      SciTech Connect

      Chiboucas, Kristin; Jacobs, Bradley A.; Tully, R. Brent; Karachentsev, Igor D. E-mail: bjacobs@ifa.hawaii.edu E-mail: ikar@luna.sao.ru

      2013-11-01

      We have followed up on the results of a 65 deg{sup 2} CFHT/MegaCam imaging survey of the nearby M81 Group searching for faint and ultra-faint dwarf galaxies. The original survey turned up 22 faint candidate dwarf members. Based on two-color HST ACS/WFC and WFPC2 photometry, we now confirm 14 of these as dwarf galaxy members of the group. Distances and stellar population characteristics are discussed for each. To a completeness limit of M{sub r{sup '}}= -10, we find a galaxy luminosity function slope of –1.27 ± 0.04 for the M81 Group. In this region, there are now 36 M81 Group members known, including 4 blue compact dwarfs; 8 other late types including the interacting giants M81, NGC 3077, and M82; 19 early type dwarfs; and at least 5 potential tidal dwarf galaxies. We find that the dSph galaxies in M81 appear to lie in a flattened distribution, similar to that found for the Milky Way and M31. One of the newly discovered dSph galaxies has properties similar to the ultra-faint dwarfs being found in the Local Group with a size R{sub e} ∼ 100 pc and total magnitude estimates M{sub r{sup '}}= -6.8 and M{sub I} ∼ –9.1.

    8. TODCOR: A New Two-Dimensional Correlation Technique to Analyze Stellar Spectra in Search for Faint Companions

      NASA Astrophysics Data System (ADS)

      Mazeh, T.; Zucker, S.; Smith, H.

      1993-12-01

      TODCOR is a new TwO-Dimensional CORrelation technique to measure radial velocities of two components of a spectroscopic binary (Zucker and Mazeh 1993, ApJ, in press). Assuming the spectra of the two components are known, the technique correlates an observed binary spectrum against a combination of the two spectra with different shifts. TODCOR measures simultaneously the radial velocities of the two stars by finding the maximum correlation. A few real single-line spectroscopic binaries already have been turned into double-line systems with TODCOR, demonstrating the power of the technique. One of the advantages of TODCOR is its ability to detect a very faint companion in a combined spectrum, and to measure its radial velocity. We present numerical tests in which we applied TODCOR to simulated spectra which were prepared as combinations of two observed infrared spectra with various luminosity ratios, together with random noise. These tests show that TODCOR can detect in principle a very faint secondary spectrum and measure correctly its velocity, provided the combined spectrum has adequate spectral coverage and S/N. Measuring the radial velocity of the faint secondary will enable us to estimate its mass, making the technique a very useful tool in the search for brown dwarfs and giant planets around nearby stars.

    9. Measuring the Star Formation Rate of the Universe at z 1 from H-alpha with Multi-Object Near-Infrared Spectroscopy

      NASA Astrophysics Data System (ADS)

      Bunker, Andrew J.; Doherty, M.; Sharp, R.; Parry, I.; Dalton, G.; Lewis, I.

      2006-12-01

      We have demonstrated the first near-infrared multi-object spectrograph,CIRPASS, on the 4.2-m William Herschel Telescope (WHT) and the 3.9-m Anglo-Australian Telescope. We have conducted an Hα survey of 38 0.77 1. This will resolve one of the long-standing puzzles in extragalactic astrophysics the true evolution of the Madau-Lilly diagram of star formation density.

    10. Variable Stars in the Field of the Hydra II Ultra-faint Dwarf Galaxy

      NASA Astrophysics Data System (ADS)

      Vivas, A. Katherina; Olsen, Knut; Blum, Robert; Nidever, David L.; Walker, Alistair R.; Martin, Nicolas F.; Besla, Gurtina; Gallart, Carme; van der Marel, Roeland P.; Majewski, Steven R.; Kaleida, Catherine C.; Muñoz, Ricardo R.; Saha, Abhijit; Conn, Blair C.; Jin, Shoko

      2016-05-01

      We report the discovery of one RR Lyrae star in the ultra-faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Inter-American Observatory, Chile. The association of the RR Lyrae star discovered here with Hydra II is clear because is located at 42\\prime\\prime from the center of the dwarf, well within its half-light radius of 102\\prime\\prime . The RR Lyrae star has a mean magnitude of i=21.30+/- 0.04 which is too faint to be a field halo star. This magnitude translates to a heliocentric distance of 151 ± 8 kpc for Hydra II; this value is ∼ 13% larger than the estimate from the discovery paper based on the average magnitude of several blue horizontal branch star candidates. The new distance implies a slightly larger half-light radius of {76}-10+12 pc and a brighter absolute magnitude of {M}V=-5.1+/- 0.3, which keeps this object within the realm of the dwarf galaxies. A comparison with other RR Lyrae stars in ultra-faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid) which are likely not related with Hydra II.

    11. ISOCAM 15 Micron Search for Distant Infrared Galaxies Lensed by Clusters

      NASA Astrophysics Data System (ADS)

      Barvainis, Richard; Antonucci, Robert; Helou, George

      1999-08-01

      In a search for lensed infrared galaxies, ISOCAM images have been obtained toward the rich clusters Abell 2218 and Abell 2219 at 15 mum. Nine galaxies (four in Abell 2218 and five in Abell 2219) were detected with flux levels in the range 530-1100 muJy. Three of the galaxies detected in Abell 2218 have previously known redshifts; of these one is a foreground galaxy, and the other two are lensed background galaxies at z=0.474 and z=1.032. One of the objects detected in the field of Abell 2219 is a faint, optically red, extreme infrared-dominated galaxy with a probable redshift of 1.048.

    12. A CCD survey for faint high-latitude carbon stars

      NASA Technical Reports Server (NTRS)

      Green, Paul J.; Margon, Bruce; Anderson, Scott F.; Cook, Kem H.

      1994-01-01

      We describe a wide-area CCD survey to search for faint high-latitude carbon (FHLC) stars. Carbon giants provide excellent probes of the structure and kinematics of the outer Galactic halo. We use two-color photometric selection with large-format CCDs to cover 52 sq deg of sky to a depth of about V = 18. Of 94 faint C star candidates from our own CCD survey, one highly ranked V = 17 candidate was found to have a strong carbon and CN bands. We estimate that, to a depth of V = 18, the surface density of FHLC stars is 0.02 deg(exp -2). An updated FHLC sample is used to constrain halo kinematic and structural parameters. Although larger samples are needed, the effective radius of FHLC giants, assuming a de Vancouleurs law distribution, is larger than that for Galactic globular clusters.

    13. Can waterbelt climates resolve the faint young Sun paradox?

      NASA Astrophysics Data System (ADS)

      Wolf, E. T.; Toon, O. B.

      2012-12-01

      Ancient sediments indicate that liquid water and primitive life were ubiquitous on the Archean Earth despite the faint young Sun. However, energy balance and radiative-convective models require improbably high greenhouse gas abundances to obtain non-glacial climates, violating constraints from geochemical data. A self-consistent solution to the faint young Sun paradox has remained elusive. Here we use the NCAR Community Atmosphere Model version 3 with thermodynamic ocean and sea ice components to simulate the climate circa 2.8 billion years ago. To maintain present day surface temperatures, 0.06 bar of CO2 in a 1 bar atmosphere is required to compensate for a 20 percent reduction in the solar constant. However, waterbelt climates having stable low latitude sea ice margins can be maintained with as little as 500 ppm of CO2 and no additional trace greenhouse species. With 5000 ppm of CO2 nearly 60 percent of the planet remains free from ice. The early Earth is resistant to hard snowball glaciations instead favoring waterbelt climates. The coexistence of a faint young Sun and a weak greenhouse does not exclude the presence of liquid water at the Archean surface.

    14. ALMA Census of Faint 1.2 mm Sources Down to ~ 0.02 mJy: Extragalactic Background Light and Dust-poor, High-z Galaxies

      NASA Astrophysics Data System (ADS)

      Fujimoto, Seiji; Ouchi, Masami; Ono, Yoshiaki; Shibuya, Takatoshi; Ishigaki, Masafumi; Nagai, Hiroshi; Momose, Rieko

      2016-01-01

      We present statistics of 133 faint 1.2 mm continuum sources detected in about 120 deep Atacama Large Millimeter/submillimeter Array (ALMA) pointing data that include all the archival deep data available by 2015 June. We derive number counts of 1.2 mm continuum sources down to 0.02 mJy partly with the assistance of gravitational lensing, and find that the total integrated 1.2 mm flux of the securely identified sources is {22.9}-5.6+6.7 Jy deg-2 which corresponds to {104}-25+31% of the extragalactic background light (EBL) measured by Cosmic Background Explorer observations. These results suggest that the major 1.2 mm EBL contributors are sources with 0.02 mJy, and that very faint 1.2 mm sources with ≲0.02 mJy contribute negligibly to the EBL with the possible flattening and/or truncation of number counts in this very faint flux regime. To understand the physical origin of our faint ALMA sources, we measure the galaxy bias bg by the counts-in-cells technique, and place a stringent upper limit of bg < 3.5 that is not similar to bg values of massive distant red galaxies and submillimeter galaxies but comparable to those of UV-bright, star-forming BzK galaxies (sBzKs) and Lyman break galaxies (LBGs). Moreover, in the optical and near-infrared (NIR) deep fields, we identify optical-NIR counterparts for 59% of our faint ALMA sources, the majority of which have luminosities, colors, and the IRX-β relation the same as sBzKs and LBGs. We thus conclude that about a half of our faint ALMA sources are dust-poor, high-z galaxies as known as sBzKs and LBGs in optical studies, and that these faint ALMA sources are not miniature (U)LIRGs simply scaled down with the infrared brightness.

    15. Herschel Discovery of a New Class of Cold, Faint Debris Discs

      NASA Technical Reports Server (NTRS)

      Eiroal, C.; Marshall, J. P.; Mora, A.; Krivov, A. V.; Montesinos, B.; Absil, O.; Ardila, D.; Arevalo, M.; Augereau, J.-Ch.; Bayo, A.; Danchi, W.; del Burgo, C.; Ertel, S.; Fridlund, M.; Gonzalez-Garcia, B. M.; Heras, A. M.; Lebreton, J.; Liseau, R.; Maldonado, J.; Meeus, G.; Montes, D.; Pilbratt, G. L.; Roberge, A.; Sanz-Forcada, J.; Stapelfeldt, K.

      2011-01-01

      We present Herschel PACS 100 and 160 micron observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel Open Time Key Programme (OTKP) DUNES (DUst around NEarby Stars). Our observations show small infrared excesses at 160 m for all three stars. HD 210277 also shows a small excess at 100 micron, while the 100 micron fluxes of alpha Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. alpha Men and HD 88230 are spatially resolved in the PACS 160 m images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from approx 115 to <= 250 AU. The estimated black body temperatures from the 100 and 160 micron fluxes are approx < 22 K, while the fractional luminosity of the cold dust is L(sub dust) / L(*) approx 10 (exp 6) close to the luminosity of the Solar-System's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars and cannot easily be explained by invoking "classical" debris disc models.

    16. Herschel Discovery of a New class of Cold, Faint Debris Discs

      NASA Technical Reports Server (NTRS)

      Eiroa, C.; Marshall, J. P.; Mora, A.; Krivov, A. V.; Montesinos, B.; Absil, O.; Ardila, D.; Arevalo, M.; Augereau, J. -Ch.; Bayo, A.; Danchi, W.; del Burgo, C.; Ertel, S.; Fridlund, M.; Gonzalez-Garcia, B. M.; Heras, A. M.; Lebreton, J.; Liseau, R.; Maldonado, J.; Meeus, G.; Montes, D.; Pilbratt, G. L.; Roberge, A.; Sanz-Forcada, J.; Stapelfeldt, K.

      2012-01-01

      We present Herschel PACS 100 and 160 micron observations of the solar-type stars alpha Men, HD 88230 and HD 210277, which form part of the FGK stars sample of the Herschel Open Time Key Programme (OTKP) DUNES (DUst around NEarby Stars). Our observations show small infrared excesses at 160 micron for all three stars. HD 210277 also shows a small excess at 100 micron. while the 100 micron fluxes of a Men and HD 88230 agree with the stellar photospheric predictions. We attribute these infrared excesses to a new class of cold, faint debris discs. alpha Men and HD 88230 are spatially resolved in the PACS 160 micron images, while HD 210277 is point-like at that wavelength. The projected linear sizes of the extended emission lie in the range from approximately 115 to <= 250 AU. The estimated black body temperatures from the 100 and 160 micron fluxes are approximately < 22 K, while the fractional luminosity of the cold dust is L(dust)/ L(star) approximates 10(exp -6), close to the luminosity of the Solar-System's Kuiper belt. These debris discs are the coldest and faintest discs discovered so far around mature stars and cannot easily be explained by invoking "classical" debris disc models.

    17. FAINT NEAR-ULTRAVIOLET/FAR-ULTRAVIOLET STANDARDS FROM SWIFT/UVOT, GALEX, AND SDSS PHOTOMETRY

      SciTech Connect

      Siegel, Michael H.; Hoversten, Erik A.; Roming, Peter W. A.; Brown, Peter E-mail: hoversten@astro.psu.ed E-mail: brown@astro.psu.ed

      2010-12-10

      At present, the precision of deep ultraviolet photometry is somewhat limited by the dearth of faint ultraviolet standard stars. In an effort to improve this situation, we present a uniform catalog of 11 new faint (u {approx} 17) ultraviolet standard stars. High-precision photometry of these stars has been taken from the Sloan Digital Sky Survey and Galaxy Evolution Explorer archives and combined with new data from the Swift Ultraviolet Optical Telescope to provide precise photometric measures extending from the near-infrared to the far-ultraviolet. These stars were chosen because they are known to be hot (20, 000 < T{sub eff} < 50, 000 K) DA white dwarfs with published Sloan spectra that should be photometrically stable. This careful selection allows us to compare the combined photometry and Sloan spectroscopy to models of pure hydrogen atmospheres to both constrain the underlying properties of the white dwarfs and test the ability of white dwarf models to predict the photometric measures. We find that the photometry provides good constraints on white dwarf temperatures, which demonstrates the ability of Swift/UVOT to investigate the properties of hot luminous stars. We further find that the models reproduce the photometric measures in all 11 passbands to within their systematic uncertainties. Within the limits of our photometry, we find the standard stars to be photometrically stable. This success indicates that the models can be used to calibrate additional filters to our standard system, permitting easier comparison of photometry from heterogeneous sources. The largest source of uncertainty in the model fitting is the uncertainty in the foreground reddening curve, a problem that is especially acute in the UV.

    18. Searching for Faint Companions to Nearby Stars with the Hubble Space Telescope

      NASA Technical Reports Server (NTRS)

      Schroeder, Daniel J.; Golimowski, David A.

      1996-01-01

      A search for faint companions (FC's) to selected stars within 5 pc of the Sun using the Hubble Space Telescope's Planetary Camera (PC) has been initiated. To assess the PC's ability to detect FCs, we have constructed both model and laboratory-simulated images and compared them to actual PC images. We find that the PC's point-spread function (PSF) is 3-4 times brighter over the angular range 2-5 sec than the PSF expected for a perfect optical system. Azimuthal variations of the PC's PSF are 10-20 times larger than expected for a perfect PSF. These variations suggest that light is scattered nonuniformly from the surface of the detector. Because the anomalies in the PC's PSF cannot be precisely simulated, subtracting a reference PSF from the PC image is problematic. We have developed a computer algorithm that identifies local brightness anomalies within the PSF as potential FCs. We find that this search algorithm will successfully locate FCs anywhere within the circumstellar field provided that the average pixel signal from the FC is at least 10 sigma above the local background. This detection limit suggests that a comprehensive search for extrasolar Jovian planets with the PC is impractical. However, the PC is useful for detecting other types of substellar objects. With a stellar signal of 10(exp 9) e(-), for example, we may detect brown dwarfs as faint as M(sub I) = 16.7 separated by 1 sec from alpha Cen A.

    19. Star/galaxy separation at faint magnitudes: Application to a simulated Dark Energy Survey

      SciTech Connect

      Soumagnac, M.T.; et al.

      2013-06-21

      We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the Gravitational Weak Lensing and Large Scale Structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by Point Spread Function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use Principal Component Analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multi-parameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SExtractor), especially at faint magnitudes: it increases the purity by up to 20% for stars and by up to 12% for galaxies, at i-magnitude fainter than 23.

    20. Faint blue counts from formation of dwarf galaxies at z approximately equals 1

      NASA Technical Reports Server (NTRS)

      Babul, Arif; Rees, Martin J.

      1993-01-01

      The nature of faint blue objects (FBO's) has been a source of much speculation since their detection in deep CCD images of the sky. Their high surface density argues against them being progenitors of present-day bright galaxies and since they are only weakly clustered on small scales, they cannot be entities that merged together to form present-day galaxies. Babul & Rees (1992) have suggested that the observed faint blue counts may be due to dwarf elliptical galaxies undergoing their initial starburst at z is approximately equal to 1. In generic hierarchical clustering scenarios, however, dwarf galaxy halos (M is approximately 10(exp 9) solar mass) are expected to form at an earlier epoch; for example, typical 10(exp 9) solar mass halos will virialize at z is approximately equal to 2.3 if the power-spectrum for the density fluctuations is that of the standard b = 2 cold dark matter (CDM) model. Under 'ordinary conditions' the gas would rapidly cool, collect in the cores, and undergo star-formation. Conditions at high redshifts are far from 'ordinary'. The intense UV background will prevent the gas in the dwarf halos from cooling, the halos being released from their suspended state only when the UV flux has diminished sufficiently.

    1. Star/galaxy separation at faint magnitudes: application to a simulated Dark Energy Survey

      NASA Astrophysics Data System (ADS)

      Soumagnac, M. T.; Abdalla, F. B.; Lahav, O.; Kirk, D.; Sevilla, I.; Bertin, E.; Rowe, B. T. P.; Annis, J.; Busha, M. T.; Da Costa, L. N.; Frieman, J. A.; Gaztanaga, E.; Jarvis, M.; Lin, H.; Percival, W. J.; Santiago, B. X.; Sabiu, C. G.; Wechsler, R. H.; Wolz, L.; Yanny, B.

      2015-06-01

      We address the problem of separating stars from galaxies in future large photometric surveys. We focus our analysis on simulations of the Dark Energy Survey (DES). In the first part of the paper, we derive the science requirements on star/galaxy separation, for measurement of the cosmological parameters with the gravitational weak lensing and large-scale structure probes. These requirements are dictated by the need to control both the statistical and systematic errors on the cosmological parameters, and by point spread function calibration. We formulate the requirements in terms of the completeness and purity provided by a given star/galaxy classifier. In order to achieve these requirements at faint magnitudes, we propose a new method for star/galaxy separation in the second part of the paper. We first use principal component analysis to outline the correlations between the objects parameters and extract from it the most relevant information. We then use the reduced set of parameters as input to an Artificial Neural Network. This multiparameter approach improves upon purely morphometric classifiers (such as the classifier implemented in SEXTRACTOR), especially at faint magnitudes: it increases the purity by up to 20 per cent for stars and by up to 12 per cent for galaxies, at i-magnitude fainter than 23.

    2. An extreme-AO search for giant planets around a white dwarf. VLT/SPHERE performance on a faint target GD 50

      NASA Astrophysics Data System (ADS)

      Xu, S.; Ertel, S.; Wahhaj, Z.; Milli, J.; Scicluna, P.; Bertrang, G. H.-M.

      2015-07-01

      Context. Little is known about the planetary systems around single white dwarfs, although there is strong evidence that they do exist. Aims: We performed a pilot study with the extreme-AO system on the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the Very Large Telescopes (VLT) to look for giant planets around a young white dwarf, GD 50. Methods: We were awarded science verification time on the new ESO instrument SPHERE. Observations were made with the InfraRed Dual-band Imager and Spectrograph in classical imaging mode in H band. Results: Despite the faintness of the target (14.2 mag in R band), the AO loop was closed and a strehl of 37% was reached in H band. No objects were detected around GD 50. We achieved a 5-sigma contrast of 6.2, 8.0, and 8.25 mag at 0.̋2, 0.̋4, and 0.̋6 and beyond, respectively. We exclude any substellar objects more massive than 4.0 MJ at 6.2 au, 2.9 MJ at 12.4 au, and 2.8 MJ at 18.6 au and beyond. This rivals the previous upper limit set by Spitzer. We further show that SPHERE is the most promising instrument available to search for close-in substellar objects around nearby white dwarfs. Based on observations made with European Southern Observatory (ESO) telescopes at the La Silla Paranal Observatory under program 60.A-9373(A).Figure 4 is available in electronic form at http://www.aanda.org

    3. Infrared microscope inspection apparatus

      DOEpatents

      Forman, Steven E.; Caunt, James W.

      1985-02-26

      Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface.

    4. Infrared microscope inspection apparatus

      DOEpatents

      Forman, S.E.; Caunt, J.W.

      1985-02-26

      Apparatus and system for inspecting infrared transparents, such as an array of photovoltaic modules containing silicon solar cells, includes an infrared microscope, at least three sources of infrared light placed around and having their axes intersect the center of the object field and means for sending the reflected light through the microscope. The apparatus is adapted to be mounted on an X-Y translator positioned adjacent the object surface. 4 figs.

    5. The Infrared Hunter

      NASA Technical Reports Server (NTRS)

      2006-01-01

      [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

      This image composite compares infrared and visible views of the famous Orion nebula and its surrounding cloud, an industrious star-making region located near the hunter constellation's sword. The infrared picture is from NASA's Spitzer Space Telescope, and the visible image is from the National Optical Astronomy Observatory, headquartered in Tucson, Ariz.

      In addition to Orion, two other nebulas can be seen in both pictures. The Orion nebula, or M42, is the largest and takes up the lower half of the images; the small nebula to the upper left of Orion is called M43; and the medium-sized nebula at the top is NGC 1977. Each nebula is marked by a ring of dust that stands out in the infrared view. These rings make up the walls of cavities that are being excavated by radiation and winds from massive stars. The visible view of the nebulas shows gas heated by ultraviolet radiation from the massive stars.

      Above the Orion nebula, where the massive stars have not yet ejected much of the obscuring dust, the visible image appears dark with only a faint glow. In contrast, the infrared view penetrates the dark lanes of dust, revealing bright swirling clouds and numerous developing stars that have shot out jets of gas (green). This is because infrared light can travel through dust, whereas visible light is stopped short by it.

      The infrared image shows light captured by Spitzer's infrared array camera. Light with wavelengths of 8 and 5.8 microns (red and orange) comes mainly from dust that has been heated by starlight. Light of 4.5 microns (green) shows hot gas and dust; and light of 3.6 microns (blue) is from starlight.

    6. Distribution of Faint Atomic Gas in Hickson Compact Groups

      NASA Astrophysics Data System (ADS)

      Borthakur, Sanchayeeta; Yun, Min Su; Verdes-Montenegro, Lourdes; Heckman, Timothy M.; Zhu, Guangtun; Braatz, James A.

      2015-10-01

      We present 21 cm H i observations of four Hickson Compact Groups (HCGs) with evidence for a substantial intragroup medium using the Robert C. Byrd Green Bank Telescope (GBT). By mapping H i emission in a region of 25‧ × 25‧ (140–650 kpc) surrounding each HCG, these observations provide better estimates of H i masses. In particular, we detected 65% more H i than that detected in the Karl G. Jansky Very Large Array (VLA) imaging of HCG 92. We also identify whether the diffuse gas has the same spatial distribution as the high surface brightness (HSB) H i features detected in the VLA maps of these groups by comparing the H i strengths between the observed and modeled masses based on VLA maps. We found that the H i observed with the GBT has a similar spatial distribution to the HSB structures in HCG 31 and HCG 68. Conversely, the observed H i distributions in HCG 44 and HCG 92 were extended and showed significant offsets from the modeled masses. Most of the faint gas in HCG 44 lies to the northeast–southwest region and in HCG 92 lies in the northwest region of their respective groups. The spatial and dynamical similarities between the total (faint+HSB) and the HSB H i indicate that the faint gas is of tidal origin. We found that the gas will survive ionization by the cosmic UV background and the escaping ionizing photons from the star-forming regions and stay primarily neutral for at least 500 Myr.

    7. CCD time-resolved photometry of faint cataclysmic variables. III

      NASA Technical Reports Server (NTRS)

      Howell, Steve B.; Szkody, Paula; Kreidl, Tobias J.; Mason, Keith O.; Puchnarewicz, E. M.

      1990-01-01

      CCD time-resolved photometry in V, B, and near-IR for 17 faint cataclysmic variables (CVs) is presented and analyzed. The data are obtained at Kitt Peak National Observatory, the Perkins reflector, Lowell Observatory, and the Observatorio del Roque de los Muchachos from April-June 1989. The degree of variability and periodicities for the CVs are examined. It is observed that the variability of most of the stars is consistent with CV class behavior. Orbital periods for five CVs are determined, and three potential eclipsing systems are detected.

    8. Photometric activity of UX orionis stars and related objects in the near infrared and optical: CO Ori, RR Tau, UX Ori, and VV Ser

      NASA Astrophysics Data System (ADS)

      Shenavrin, V. I.; Rostopchina-Shakhovskaya, A. N.; Grinin, V. P.; Demidova, T. V.; Shakhovskoi, D. N.; Belan, S. P.

      2016-08-01

      This paper continues a study of the photometric activity of UX Ori stars in the optical and near-infrared ( JHKLM bands) initiated in 2000. For comparison, the list of program stars contains two Herbig Ae stars that are photometrically quiet in the optical: MWC480 andHD179218. Fadings ofUXOri stars in the optical ( V band) due to sporadic increases of the circumstellar extinction are also observed in the infrared (IR), but with decreasing amplitude. Two stars, RR Tau and UX Ori, displayed photometric events when V -band fadings were accompanied by an increase in IR fluxes. Among the two Herbig Ae stars that are photometrically quiet in the optical, MWC 480 proved to be fairly active in the IR. Unlike the UX Ori stars, the variation amplitude of MWC 480 increases from the J band to the M band. In the course of the observations, no deep fadings in the IR bands were detected. This indicates that eclipses of the program stars have a local nature, and are due to extinction variations in the innermost regions of the circumstellar disks. The results presented testify to an important role of the alignment of the circumstellar disks relative to the direction towards the observer in determining the observed IR variability of young stars.

    9. Merged infrared catalogue

      NASA Technical Reports Server (NTRS)

      Schmitz, M.; Brown, L. W.; Mead, J. M.; Nagy, T. A.

      1978-01-01

      A compilation of equatorial coordinates, spectral types, magnitudes, and fluxes from five catalogues of infrared observations is presented. This first edition of the Merged Infrared Catalogue contains 11,201 oservations from the Two-Micron Sky Survey, Observations of Infrared Radiation from Cool Stars, the Air Force Geophysics Laboratory four Color Infrared Sky Survey and its Supplemental Catalog, and from Catalog of 10 micron Celestial Objects (HALL). This compilation is a by-product of a computerized infrared data base under development at Goddard Space Flight Center; the objective is to maintain a complete and current record of all infrared observations from 1 micron m to 1000 micron m of nonsolar system objects. These observations are being placed into a standardized system.

    10. ARACHNID: A prototype object-oriented database tool for distributed systems

      NASA Technical Reports Server (NTRS)

      Younger, Herbert; Oreilly, John; Frogner, Bjorn

      1994-01-01

      This paper discusses the results of a Phase 2 SBIR project sponsored by NASA and performed by MIMD Systems, Inc. A major objective of this project was to develop specific concepts for improved performance in accessing large databases. An object-oriented and distributed approach was used for the general design, while a geographical decomposition was used as a specific solution. The resulting software framework is called ARACHNID. The Faint Source Catalog developed by NASA was the initial database testbed. This is a database of many giga-bytes, where an order of magnitude improvement in query speed is being sought. This database contains faint infrared point sources obtained from telescope measurements of the sky. A geographical decomposition of this database is an attractive approach to dividing it into pieces. Each piece can then be searched on individual processors with only a weak data linkage between the processors being required. As a further demonstration of the concepts implemented in ARACHNID, a tourist information system is discussed. This version of ARACHNID is the commercial result of the project. It is a distributed, networked, database application where speed, maintenance, and reliability are important considerations. This paper focuses on the design concepts and technologies that form the basis for ARACHNID.

    11. GT2_ncox_1: Faint Extended Dust Envelopes of Young Planetary Nebulae

      NASA Astrophysics Data System (ADS)

      Cox, N.

      2011-05-01

      We propose to trace the distribution of cold dust in the extended envelopes of a selected sample of young Planetary Nebulae (PNe). Information on the mass-loss and overall envelope ejection process of Asymptotic Giant Branch (AGB) stars is imprinted in the morphology of the extended dust shells formed throughout the AGB phase. In particular the origin of asymmetrical PN shapes and their relation to spherical mass-loss presumed to occur on the AGB phase can be illuminated upon. We propose to use PACS to follow-up on AKARI/FIS observations of young PNe to study their mass-loss history. Only Herschel's unprecedented spatial resolution and sensitivity in the far-IR can detect the faint extended cold dust emission in these objects.

    12. A model atmosphere analysis of the faint early-type halo star PHL 346

      NASA Astrophysics Data System (ADS)

      Keenan, F. P.; Lennon, D. J.; Brown, P. J. F.; Dufton, P. L.

      1986-08-01

      Stellar equivalent widths and hydrogen line profiles, measured from high-resolution optical spectra obtained with the 2.5 m Issac Newton Telescope, are used in conjunction with model atmosphere calculations to determine the atmospheric parameters and chemical composition of the faint, high galactic latitude early-type star PHL 346. The effective temperature (Teff = 22,600 + or - 1000 K) and surface gravity (log g = 3.6 + or - 0.2), as well as the chemical composition, are found to be similar to those of normal OB stars. Therefore, it is concluded that PHL 346 is an ordinary Population I object, at a z distance of 8.7 + or - 1.5 kpc. The relatively small stellar velocity in the z-direction (Vz = +56 + or - 10 km/s) then implies that PHL 346 must have been formed in the halo, possibly from galactic fountain material at a z distance of about 6 kpc.

    13. Hubble Space Telescope faint object spectrograph instrument handbook, version 5.0

      NASA Technical Reports Server (NTRS)

      Kinney, A. L. (Editor)

      1994-01-01

      This version of the FOS Instrument Handbook is for the refurbished telescope, which is affected by an increase in throughput, especially for the smaller apertures, a decrease in efficiency due to the extra reflections of the COSTAR optics, and a change in focal length. The improved PSF affects all exposure time calculations due to better aperture throughputs and increases the spectral resolution. The extra reflections of COSTAR decrease the efficiency by 10-20 percent. The change in focal length affects the aperture sizes as projected on the sky. The aperture designations that are already in use both in the exposure logsheets and in the project data base (PDB) have not been changed. Apertures are referred to here by their size, followed by the designation used on the exposure logsheet.

    14. Guaranteed time observations support for Faint Object Spectrograph (FOS) on HST

      NASA Technical Reports Server (NTRS)

      Harms, Richard

      1994-01-01

      The goals of the GTO effort are for investigations defined in previous years by the IDT to be carried out as HST observations and for the results to be communicated to the scientific community and to the public. The search for possible black holes in the nuclei of both normal and active nucleus galaxies has had to be delayed to the post-servicing era. FOS spectropolarimetric observations of the nuclear region of the peculiar Seyfert galaxy Mrk 231 reveal that the continuum polarization peaks at 18% in the near UV and then declines rapidly toward shorter wavelengths. The papers on the absorption line analysis for our galactic halo address the spatial distribution of high and intermediate level ions in the halo and illustrate the patchy and heterogeneous nature of the halo. The papers on the scattering characteristics of the HST/FOS have provided us with data that shows that the HST mirror surfaces are quite smooth, even at the UV wavelengths. WF-PC and FOC images of the halo PN K648 have been fully analyzed.

    15. DISCOVERIES FROM A NEAR-INFRARED PROPER MOTION SURVEY USING MULTI-EPOCH TWO MICRON ALL-SKY SURVEY DATA

      SciTech Connect

      Kirkpatrick, J. Davy; Cutri, Roc M.; Looper, Dagny L.; Burgasser, Adam J.; Schurr, Steven D.; Cushing, Michael C.; Cruz, Kelle L.; Sweet, Anne C.; Knapp, Gillian R.; Barman, Travis S.; Bochanski, John J.; Roellig, Thomas L.; McLean, Ian S.; McGovern, Mark R.; Rice, Emily L.

      2010-09-15

      We have conducted a 4030 deg{sup 2} near-infrared proper motion survey using multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find 2778 proper motion candidates, 647 of which are not listed in SIMBAD. After comparison to Digitized Sky Survey images, we find that 107 of our proper motion candidates lack counterparts at B, R, and I bands and are thus 2MASS-only detections. We present results of spectroscopic follow-up of 188 targets that include the infrared-only sources along with selected optical-counterpart sources with faint reduced proper motions or interesting colors. We also establish a set of near-infrared spectroscopic standards with which to anchor near-infrared classifications for our objects. Among the discoveries are six young field brown dwarfs, five 'red L' dwarfs, three L-type subdwarfs, twelve M-type subdwarfs, eight 'blue L' dwarfs, and several T dwarfs. We further refine the definitions of these exotic classes to aid future identification of similar objects. We examine their kinematics and find that both the 'blue L' and 'red L' dwarfs appear to be drawn from a relatively old population. This survey provides a glimpse of the kinds of research that will be possible through time-domain infrared projects such as the UKIDSS Large Area Survey, various VISTA surveys, and WISE, and also through z- or y-band enabled, multi-epoch surveys such as Pan-STARRS and LSST.

    16. Detectability of Ultra Faint Dwarf Galaxies with Gaia

      NASA Astrophysics Data System (ADS)

      Mateu, C.; Antoja, T.; Aguilar, L.; Figueras, F.; Brown, A.; Antiche, E.; Hernández-Pérez, F.; Valenzuela, O.; Aparicio, A.; Hidalgo, S.; Velázquez, H.

      2014-07-01

      We present a technique to detect Ultra-Faint Dwarf Galaxies (UFDs) in the Galactic Halo, using sky and proper motion information.The method uses wavelet transforms to detect peaks in the sky and proper motion planes, and to evaluate the probability of these being stochastic fluctuations. We aim to map thoroughly the detection limits of this technique. For this, we have produced a library of 15,000 synthetic UFDs, embedded in the Gaia Universe Model Snapshot (GUMS) background (Robin et al. 2012), each at a different distance, different luminosity, half-light radius, velocity dispersion and center-of-mass velocity, varying in ranges that extend well beyond those spanned by known classical and ultra-faint dSphs. We use these synthetic UFDs as a benchmark to characterize the completeness and detection limits of our technique, and present our results as a function of different physical and observable parameters of the UFDs (see full poster for more details at https://gaia.ub.edu/Twiki/pub/GREATITNFC/ProgramFinalconference/Poster_UFGX_Bcn_C_Mateu.pdf).

    17. Performance of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) high-resolution near-infrared multi-object fiber spectrograph

      NASA Astrophysics Data System (ADS)

      Wilson, John C.; Hearty, F.; Skrutskie, M. F.; Majewski, S. R.; Schiavon, R.; Eisenstein, D.; Gunn, J.; Holtzman, J.; Nidever, D.; Gillespie, B.; Weinberg, D.; Blank, B.; Henderson, C.; Smee, S.; Barkhouser, R.; Harding, A.; Hope, S.; Fitzgerald, G.; Stolberg, T.; Arns, J.; Nelson, M.; Brunner, S.; Burton, A.; Walker, E.; Lam, C.; Maseman, P.; Barr, J.; Leger, F.; Carey, L.; MacDonald, N.; Ebelke, G.; Beland, S.; Horne, T.; Young, E.; Rieke, G.; Rieke, M.; O'Brien, T.; Crane, J.; Carr, M.; Harrison, C.; Stoll, R.; Vernieri, M.; Shetrone, M.; Allende-Prieto, C.; Johnson, J.; Frinchaboy, P.; Zasowski, G.; Garcia Perez, A.; Bizyaev, D.; Cunha, K.; Smith, V. V.; Meszaros, Sz.; Zhao, B.; Hayden, M.; Chojnowski, S. D.; Andrews, B.; Loomis, C.; Owen, R.; Klaene, M.; Brinkmann, J.; Stauffer, F.; Long, D.; Jordan, W.; Holder, D.; Cope, F.; Naugle, T.; Pfaffenberger, B.; Schlegel, D.; Blanton, M.; Muna, D.; Weaver, B.; Snedden, S.; Pan, K.; Brewington, H.; Malanushenko, E.; Malanushenko, V.; Simmons, A.; Oravetz, D.; Mahadevan, S.; Halverson, S.

      2012-09-01

      The Apache Point Observatory Galactic Evolution Experiment (APOGEE) uses a dedicated 300-fiber, narrow-band near-infrared (1.51-1.7 μm), high resolution (R~22,500) spectrograph to survey approximately 100,000 giant stars across the Milky Way. This three-year survey, in operation since late-summer 2011 as part of the Sloan Digital Sky Survey III (SDSS III), will revolutionize our understanding of the kinematical and chemical enrichment histories of all Galactic stellar populations. We present the performance of the instrument from its first year in operation. The instrument is housed in a separate building adjacent to the 2.5-m SDSS telescope and fed light via approximately 45-meter fiber runs from the telescope. The instrument design includes numerous innovations including a gang connector that allows simultaneous connection of all fibers with a single plug to a telescope cartridge that positions the fibers on the sky, numerous places in the fiber train in which focal ratio degradation had to be minimized, a large mosaic-VPH (290 mm x 475 mm elliptically-shaped recorded area), an f/1.4 six-element refractive camera featuring silicon and fused silica elements with diameters as large as 393 mm, three near-infrared detectors mounted in a 1 x 3 mosaic with sub-pixel translation capability, and all of these components housed within a custom, LN2-cooled, stainless steel vacuum cryostat with dimensions 1.4-m x 2.3-m x 1.3-m.

    18. Object Oriented Learning Objects

      ERIC Educational Resources Information Center

      Morris, Ed

      2005-01-01

      We apply the object oriented software engineering (OOSE) design methodology for software objects (SOs) to learning objects (LOs). OOSE extends and refines design principles for authoring dynamic reusable LOs. Our learning object class (LOC) is a template from which individualised LOs can be dynamically created for, or by, students. The properties…

    19. Verification of mesoscale objective analyses of VAS and rawinsode data using the March 1982 AVE/VAS special network data. [Atmospheric Variability Experiment/Visible-infrared spin-scan radiometer Atmospheric Sounder

      NASA Technical Reports Server (NTRS)

      Doyle, James D.; Warner, Thomas T.

      1988-01-01

      Various combinations of VAS (Visible and Infrared Spin Scan Radiometer Atmospheric Sounder) data, conventional rawinsonde data, and gridded data from the National Weather Service's (NWS) global analysis, were used in successive-correction and variational objective-analysis procedures. Analyses are produced for 0000 GMT 7 March 1982, when the VAS sounding distribution was not greatly limited by the existence of cloud cover. The successive-correction (SC) Procedure was used with VAS data alone, rawinsonde data alone, and both VAS and rawinsonde data. Variational techniques were applied in three ways. Each of these techniques was discussed.

    20. Sifting planetary mass objects at the limits of the WISE survey

      NASA Astrophysics Data System (ADS)

      Pinfield, David James; Leggett, Sandy; Gromadzki, Mariusz

      2015-08-01

      Large scale infrared imaging surveys have facilitated the discovery of sub-stellar objects in the field and as wide companions, with mass down to a few Jupiters and Teff as low as ~250K. This population may have diverse origins with formation in both circumstellar and interstellar environments, with much work still needed to properly understand the "brown dwarf-exoplanet connection". The Wide-field Infrared Survey Explorer (WISE) is currently providing the greatest sensitivity to free-floating planetary mass objects, and has revealed a new classification that covers "habitable zone" temperatures - the Y dwarfs. WISE scans the sky in a way that yields time-domain as well as colour/brightness/morphology information, and offers an expanded opportunity to discriminate between genuine sources and noise signatures near the survey limits, as well as scope to reveal very high proper motion objects in the solar neighbourhood. I have developed a Bayesian search methodology to identify the coolest faintest objects in WISE, from within the reservoir of faint contamination and noise signals. I define multi-parameter probability distributions using controlled sampling of the AllWISE database. The coolest sub-stellar objects are detected in the WISE W2 band, but are un-detected at W1, so my analysis prioritises sources that display source-like and noise-like properties respectively in these two bands. I will review the followup observations that allow me to confirm or reject candidate Y dwarfs, and present recent discoveries from the programme.

    1. LOITA: Lunar Optical/Infrared Telescope Array

      NASA Technical Reports Server (NTRS)

      1993-01-01

      LOITA (Lunar Optical/Infrared Telescope Array) is a lunar-based interferometer composed of 18 alt-azimuth telescopes arranged in a circular geometry. This geometry results in excellent uv coverage and allows baselines up to 5 km long. The angular resolution will be 25 micro-arcsec at 500 nm and the main spectral range of the array will be 200 to 1100 nm. For infrared planet detection, the spectral range may be extended to nearly 10 mu m. The telescope mirrors have a Cassegrain configuration using a 1.75 m diameter primary mirror and a 0.24 m diameter secondary mirror. A three-stage (coarse, intermediate, and fine) optical delay system, controlled by laser metrology, is used to equalize path lengths from different telescopes to within a few wavelengths. All instruments and the fine delay system are located within the instrument room. Upon exiting the fine delay system, all beams enter the beam combiner and are then directed to the various scientific instruments and detectors. The array instrumentation will consist of CCD detectors optimized for both the visible and infrared as well as specially designed cameras and spectrographs. For direct planet detection, a beam combiner employing achromatic nulling interferometry will be used to reduce star light (by several orders of magnitude) while passing the planet light. A single telescope will be capable of autonomous operation. This telescope will be equipped with four instruments: wide field and planetary camera, faint object camera, high resolution spectrograph, and faint object spectrograph. These instruments will be housed beneath the telescope. The array pointing and control system is designed to meet the fine pointing requirement of one micro-arcsec stability and to allow precise tracking of celestial objects for up to 12 days. During the lunar night, the optics and the detectors will be passively cooled to 70-80 K temperature. To maintain a continuous communication with the earth a relay satellite placed at the L4

    2. THE FAINT-END SLOPE OF THE REDSHIFT 5.7 Ly{alpha} LUMINOSITY FUNCTION

      SciTech Connect

      Henry, Alaina L.; Martin, Crystal L.; Dressler, Alan; McCarthy, Patrick; Sawicki, Marcin

      2012-01-10

      Using new Keck DEIMOS spectroscopy, we examine the origin of the steep number counts of ultra-faint emission-line galaxies recently reported by Dressler et al. We confirm six Ly{alpha} emitters (LAEs), three of which have significant asymmetric line profiles with prominent wings extending 300-400 km s{sup -1} redward of the peak emission. With these six LAEs, we revise our previous estimate of the number of faint LAEs in the Dressler et al. survey. Combining these data with the density of bright LAEs in the Cosmic Evolution Survey and Subaru Deep Field provides the best constraints to date on the redshift 5.7 LAE luminosity function (LF). Schechter function parameters, {phi}* = 4.5 Multiplication-Sign 10{sup -4} Mpc{sup -3}, L* = 9.1 Multiplication-Sign 10{sup 42} erg s{sup -1}, and {alpha} = -1.70, are estimated using a maximum likelihood technique with a model for slit-losses. To place this result in the context of the UV-selected galaxy population, we investigate how various parameterizations of the Ly{alpha} equivalent width distribution, along with the measured UV-continuum LF, affect shape and normalization of the Ly{alpha} LF. The nominal model, which uses z {approx} 6 equivalent widths from the literature, falls short of the observed space density of LAEs at the bright end, possibly indicating a need for higher equivalent widths. This parameterization of the equivalent width distribution implies that as many as 50% of our faintest LAEs should have M{sub UV} > -18.0, rendering them undetectable in even the deepest Hubble Space Telescope surveys at this redshift. Hence, ultra-deep emission-line surveys find some of the faintest galaxies ever observed at the end of the reionization epoch. Such faint galaxies likely enrich the intergalactic medium with metals and maintain its ionized state in the post-reionization era. Observations of these objects provide a glimpse of the building blocks of present-day galaxies at an early time.

    3. Emission Line Science in the Faint Infrared Grism Survey (FIGS) Sample

      NASA Astrophysics Data System (ADS)

      Smith, Mark David; Malhotra, Sangeeta; Pharo, John; Rhoads, James E.; FIGS Team

      2016-01-01

      Emission lines can reveal a bounty of information about the processes occurring within a galaxy. Physical properties such as star formation rate and metallicity can be determined from ratios of emission line fluxes. The study of emission line galaxies (ELGs) through cosmic time gives insight into the processes by which galaxies evolve. Extreme emission line galaxies (EELGs), typified by strong nebular emission lines which dominate their spectra, are of interest because they are well known to be galaxies undergoing periods of intense star formation. Slitless grism spectroscopy offers a significant advantage to the study of ELGs and EELGs, allowing for measurement of the spectra of a large number of galaxies within a field. This allows for detection of ELGs and EELGs with few selection biases. Optical follow-up of FIGS-selected sources allows for analysis of star formation rate (SFR) through H-alpha measurements over the redshift range 0.3

    4. A Classification Scheme for Young Stellar Objects Using the WIDE-FIELD INFRARED SURVEY EXPLORER ALLWISE Catalog: Revealing Low-Density Star Formation in the Outer Galaxy

      NASA Technical Reports Server (NTRS)

      Koening, X. P.; Leisawitz, D. T.

      2014-01-01

      We present an assessment of the performance of WISE and the AllWISE data release in a section of the Galactic Plane. We lay out an approach to increasing the reliability of point source photometry extracted from the AllWISE catalog in Galactic Plane regions using parameters provided in the catalog. We use the resulting catalog to construct a new, revised young star detection and classification scheme combining WISE and 2MASS near and mid-infrared colors and magnitudes and test it in a section of the Outer Milky Way. The clustering properties of the candidate Class I and II stars using a nearest neighbor density calculation and the two-point correlation function suggest that the majority of stars do form in massive star forming regions, and any isolated mode of star formation is at most a small fraction of the total star forming output of the Galaxy. We also show that the isolated component may be very small and could represent the tail end of a single mechanism of star formation in line with models of molecular cloud collapse with supersonic turbulence and not a separate mode all to itself.

    5. FAINT FUZZY STAR CLUSTERS IN NGC 1023 AS REMNANTS OF MERGED STAR CLUSTER COMPLEXES

      SciTech Connect

      Bruens, R. C.; Kroupa, P.; Fellhauer, M. E-mail: pavel@astro.uni-bonn.de

      2009-09-10

      In the lenticular galaxy NGC 1023 a third population of globular clusters (GCs), called faint fuzzies (FFs), was discovered next to the blue and red GC populations by Larsen and Brodie. While these FFs have colors comparable to the red population, the new population is fainter, larger (R{sub eff}>7 pc) and, most importantly, shows clear signs of corotation with the galactic disk of NGC 1023. We present N-body simulations verifying the hypothesis that these disk-associated FFs are related to the young massive cluster complexes (CCs) observed by Bastian et al. in M51, who discovered a mass-radius relation for these CCs. Our models have an initial configuration based on the observations from M51 and are placed on various orbits in a galactic potential derived for NGC 1023. All computations end up with a stable object containing 10%-60% of the initial CC mass after an integration time of 5 Gyr. A conversion to visual magnitudes demonstrates that the resulting objects cover exactly the observed range for FFs. Moreover, the simulated objects show projected half-mass radii between 3.6 and 13.4 pc, in good agreement with the observed FF sizes. We conclude that objects like the young massive CCs in M51 are likely progenitors of the FFs observed in NGC 1023.

    6. A sample of Swift/SDSS faint blazars

      NASA Astrophysics Data System (ADS)

      Fraga, Bernardo; Giommi, Paolo; Turriziani, Sara

      2015-12-01

      We aim here to provide a complete sample of faint (fr ≳ 1 mJy, fx ≳ 10-15 erg cm-2 s-1) blazars and blazar candidates serendipitously discovered in deep Swift images centered on Gamma-ray bursts (GRBs). By stacking all available images, we obtain exposures ranging from 104 to more than a million seconds. Since GRBs are thought to explode randomly across the sky, this set of deep fields can be considered as an unbiased survey of ≈ 12 square degrees of extragalactic sky, with sensitivities reaching a few 10-15 erg cm-2 s-1 in the 0.5-2 keV band. We then derive the x-ray Log N Log S and show that, considering that our sample may be contaminated by sources other than blazars, we are in agreement with previous estimations based on data and simulations.

    7. The faint young sun-climate paradox - Continental influences

      NASA Technical Reports Server (NTRS)

      Endal, A. S.; Schatten, K. H.

      1982-01-01

      We examine the various mechanisms which have been proposed to compensate for the climatic effects of a 30% increase in the solar luminosity over the past 4 1/2 billion years. Although atmospheric greenhouse effects have received most attention, other mechanisms may have played a role of comparable importance. In particular, we note that the development of continents during the past 2 1/2 billion years could have had a significant secular effect on the atmosphere-ocean heat transport system. As a result, past climates may have been less susceptible to complete freeze-over. A simple energy balance model is used to demonstrate the magnitude of this effect. Because the CO2 greenhouse effect is not the only means of compensating for solar evolution, the faint-young-sun problem should not be used to infer past levels of atmospheric CO2.

    8. Mass influx obtained from LLLTV observations of faint meteors

      NASA Technical Reports Server (NTRS)

      Naumann, R. J.; Clifton, K. S.

      1972-01-01

      Since the advent of low light level television (LLLTV) systems, it has been recognized that such devices offer the ability to observe meteors as faint as 10th magnitude which allows the extension of optical meteor data to masses as small as 0.0001 grams. The Space Sciences Lab at Marshall Space Flight Center has been actively engaged in such observations using image orthicons and intensified SEC vidicons. The results of these observations are presented along with an interpretation in terms of mass-flux. This interpretation includes the development of a relationship between peak luminosity of a meteor and mass, velocity, and zenith angle that was derived from single body meteor theory and compares favorably with results obtained from the Artificial Program. Also included in the mass flux interpretation is an analysis of the observation response of a LLLTV system to fixed and moving point sources.

    9. Physical Characteristics of Faint Meteors by Light Curve and High-resolution Observations

      NASA Astrophysics Data System (ADS)

      Subasinghe, Dilini; Campbell-Brown, Margaret D.; Stokan, Edward

      2014-11-01

      The physical structure of a meteoroid may be inferred from optical observations, particularly the light curve, of a meteor. For example: a classically shaped (late peaked) light curve is seen as evidence of a solid single body, whereas a symmetric light curve may indicate a dustball structure. High-resolution optical observations show how the meteoroid fragments: continuously, leaving a long wake, or discretely, leaving several distinct pieces. Calculating the orbit of the meteoroid using two station data then allows the object to be associated with asteroidal or cometary parent bodies. Optical observations thus provide simultaneous information on meteoroid structure, fragmentation mode, and origin.CAMO (the Canadian Automated Meteor Observatory) has been continuously collecting faint (masses < 10-4 kg) two station optical meteors with image-intensified narrow field (with a resolution of up to 3 meters per pixel) and wide field (26 by 19 degrees) cameras since 2010. The narrow field, telescopic cameras allow the meteor fragmentation to be studied using a pair of mirrors to track the meteor. The wide-field cameras provide the light curve and trajectory solution.We present preliminary results from classifying light curves and high-resolution optical observations for 3000 faint meteors recorded since 2010. We find that most meteors (both asteroidal and cometary) show long trails, while meteors with short trails are the second most common morphology. It is expected that meteoroids that experience negligible fragmentation have the shortest trails, so our results imply that the majority of small meteoroids fragment during ablation. A surprising observation is that almost equal fractions of asteroidal and cometary meteors fragment (showing long trails), implying a similar structure for both types of meteoroids.

    10. The Chemical Evolution of the Bootes I Ultra-faint Dwarf Galaxy

      NASA Astrophysics Data System (ADS)

      Frebel, Anna; Norris, John E.; Gilmore, Gerard; Wyse, Rosemary F. G.

      2016-08-01

      We present chemical abundance measurements of two metal-poor red giant stars in the ultra-faint dwarf galaxy Boötes I, based on Magellan/MIKE high-resolution spectra. For Boo-980, with {{[Fe/H]}}=-3.1, we present the first elemental abundance measurements, while Boo-127, with {{[Fe/H]}}=-2.0, shows abundances in good agreement with previous measurements. Light and iron-peak element abundance ratios in the two Boötes I stars, as well as those of most other Boötes I members, collected from the literature, closely resemble those of regular metal-poor halo stars. Neutron-capture element abundances Sr and Ba are systematically lower than the main halo trend and also show a significant abundance spread. Overall, this is similar to what has been found for other ultra-faint dwarf galaxies. We apply corrections to the carbon abundances (commensurate with stellar evolutionary status) of the entire sample and find 21% of stars to be carbon-enhanced metal-poor (CEMP) stars, compared to 13% without using the carbon correction. We reassess the metallicity distribution functions for the CEMP stars and non-CEMP stars, and confirm earlier claims that CEMP stars might belong to a different, earlier population. Applying a set of abundance criteria to test to what extent Boötes I could be a surviving first galaxy suggests that it is one of the earliest assembled systems that perhaps received gas from accretion from other clouds in the system, or from swallowing a first galaxy or building block type object. This resulted in the two stellar populations observable today. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

    11. Freeze, flight, fight, fright, faint: adaptationist perspectives on the acute stress response spectrum.

      PubMed

      Bracha, H Stefan

      2004-09-01

      This article reviews the existing evolutionary perspectives on the acute stress response habitual faintness and blood-injection-injury type-specific phobia (BIITS phobia). In this article, an alternative evolutionary perspective, based on recent advances in evolutionary psychology, is proposed. Specifically, that fear-induced faintness (eg, fainting following the sight of a syringe, blood, or following a trivial skin injury) is a distinct Homo sapiens-specific extreme-stress survival response to an inescapable threat. The article suggests that faintness evolved in response to middle paleolithic intra-group and inter-group violence (of con-specifics) rather than as a pan-mammalian defense response, as is presently assumed. Based on recent literature, freeze, flight, fight, fright, faint provides a more complete description of the human acute stress response sequence than current descriptions. Faintness, one of three primary physiological reactions involved in BIITS phobia, is extremely rare in other phobias. Since heritability estimates are higher for faintness than for fears or phobias, the author suggests that trait-faintness may be a useful complement to trait-anxiety as an endophenotype in research on the human fear circuitry. Some implications for the forthcoming Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition as well as for clinical, health services, and transcriptomic research are briefly discussed. PMID:15337864

    12. Crystalline water ice on the Kuiper belt object (50000) Quaoar.

      PubMed

      Jewitt, David C; Luu, Jane

      2004-12-01

      The Kuiper belt is a disk-like structure consisting of solid bodies orbiting the Sun beyond Neptune. It is the source of the short-period comets and the likely repository of the Solar System's most primitive materials. Surface temperatures in the belt are low ( approximately 50 K), suggesting that ices trapped at formation should have been preserved over the age of the Solar System. Unfortunately, most Kuiper belt objects are too faint for meaningful compositional study, even with the largest available telescopes. Water ice has been reported in a handful of objects, but most appear spectrally featureless. Here we report near-infrared observations of the large Kuiper belt object (50000) Quaoar, which reveal the presence of crystalline water ice and ammonia hydrate. Crystallinity indicates that the ice has been heated to at least 110 K. Both ammonia hydrate and crystalline water ice should be destroyed by energetic particle irradiation on a timescale of about 10(7) yr. We conclude that Quaoar has been recently resurfaced, either by impact exposure of previously buried (shielded) ices or by cryovolcanic outgassing, or by a combination of these processes. PMID:15592406

    13. The Infrared Sky.

      ERIC Educational Resources Information Center

      Habing, Harm J.; Neugebauer, Gerry

      1984-01-01

      The Infrared Astronomical Satellite (IRAS) is a survey instrument that has provided an overall view of the infrared sky and identified objects that merit further investigation. A description of the IRAS and examples of the types of astronomical data collected are presented. (JN)

    14. SMA observations on faint submillimeter galaxies with S {sub 850} < 2 mJy: Ultra dusty low-luminosity galaxies at high redshift

      SciTech Connect

      Chen, Chian-Chou; Cowie, Lennox L.; Barger, Amy J.; Williams, Jonathan P.; Wang, Wei-Hao

      2014-07-01

      We obtained Submillimeter Array (SMA) observations of eight faint (intrinsic 850 μm fluxes < 2 mJy) submillimeter galaxies (SMGs) discovered in SCUBA images of the massive lensing cluster fields A370, A2390, and A1689 and detected five. In total, we obtain five SMA detections, all of which have de-lensed fluxes <1 mJy with estimated total infrared luminosities 10{sup 10}-10{sup 12} L {sub ☉}, comparable to luminous infrared galaxies and normal star-forming galaxies. Based on the latest number counts, these galaxies contribute ∼70% of the 850 μm extragalactic background light and represent the dominant star-forming galaxy population in the dusty universe. However, only 40{sub −16}{sup +30}% of our faint SMGs would be detected in deep optical or near-infrared surveys, which suggests many of these sources are at high redshifts (z ≳ 3) or extremely dusty, and they are not included in current star formation history estimates.

    15. The Location of the CO2, Fundamental in Clathrate Hydrates and its Application to Infrared Spectra of Icy Solar System Objects

      NASA Technical Reports Server (NTRS)

      Sandford, S. A.; Mastrapa, R. M. E.; Bernstein, M. P.; Cruikshank, D. P.

      2006-01-01

      CO2 is present on the surface of many Solar System objects, but not always as a segregated, pure ice. In pure CO2-ice, the fundamental absorption is located near 4.268 micron (2343.3 wavenumbers). However, on several objects, the CO2 fundamental is shifted to higher frequency. This shift may be produced by CO2 gas trapped in another material, or adsorbed onto minerals. We have seen that a mixture of H2O, CH3OH4 and CO2 forms a type II clathrate when heated to 125 K and produces a CO2 fundamental near 4.26 micron. The exact location of the feature is strongly dependent on the initial ratio of the three components. We are currently exploring various starting ratios relevant to the Solar System to determine the minimum amount of CH3OH needed to convert all of the CO2 to the clathrate, i.e. eliminate the splitting of the CO2 fundamental. We are testing the stability of the clathrate to thermal processing and UV photolysis, and documenting the changes seen in the spectra in the wavelength range from 1-5 micron. We acknowledge financial support from the Origins of Solar Systems Program, the Planetary Geology and Geophysics and the NASA Postdoctoral Program.

    16. Catalog of infrared observations

      NASA Technical Reports Server (NTRS)

      Gezari, D. Y.; Schmitz, M.; Mead, J. M.

      1982-01-01

      The infrared astronomical data base and its principal data product, the catalog of Infrared Observations (CIO), comprise a machine readable library of infrared (1 microns to 1000 microns astronomical observations. To date, over 1300 journal articles and 10 major survey catalogs are included in this data base, which contains about 55,000 individual observations of about 10,000 different infrared sources. Of these, some 8,000 sources are identifiable with visible objects, and about 2,000 do not have known visible counterparts.

    17. Infrared Heaters

      NASA Technical Reports Server (NTRS)

      1979-01-01

      The heating units shown in the accompanying photos are Panelbloc infrared heaters, energy savers which burn little fuel in relation to their effective heat output. Produced by Bettcher Manufacturing Corporation, Cleveland, Ohio, Panelblocs are applicable to industrial or other facilities which have ceilings more than 12 feet high, such as those pictured: at left the Bare Hills Tennis Club, Baltimore, Maryland and at right, CVA Lincoln- Mercury, Gaithersburg, Maryland. The heaters are mounted high above the floor and they radiate infrared energy downward. Panelblocs do not waste energy by warming the surrounding air. Instead, they beam invisible heat rays directly to objects which absorb the radiation- people, floors, machinery and other plant equipment. All these objects in turn re-radiate the energy to the air. A key element in the Panelbloc design is a coating applied to the aluminized steel outer surface of the heater. This coating must be corrosion resistant at high temperatures and it must have high "emissivity"-the ability of a surface to emit radiant energy. The Bettcher company formerly used a porcelain coating, but it caused a production problem. Bettcher did not have the capability to apply the material in its own plant, so the heaters had to be shipped out of state for porcelainizing, which entailed extra cost. Bettcher sought a coating which could meet the specifications yet be applied in its own facilities. The company asked The Knowledge Availability Systems Center, Pittsburgh, Pennsylvania, a NASA Industrial Applications Center (IAC), for a search of NASA's files

    18. Serendipitous discovery of the faint solar twin Inti 1

      NASA Astrophysics Data System (ADS)

      Galarza, Jhon Yana; Meléndez, Jorge; Cohen, Judith G.

      2016-04-01

      Context. Solar twins are increasingly the subject of many studies owing to their wide range of applications from testing stellar evolution models to the calibration of fundamental observables; these stars are also of interest because high precision abundances could be achieved that are key to investigating the chemical anomalies imprinted by planet formation. Furthermore, the advent of photometric surveys with large telescopes motivates the identification of faint solar twins in order to set the zero point of fundamental calibrations. Aims: We intend to perform a detailed line-by-line differential analysis to verify whether 2MASS J23263267-0239363 (designated here as Inti 1) is indeed a solar twin. Methods: We determine the atmospheric parameters and differential abundances using high-resolution (R ≈ 50 000), high signal-to-noise (S/N ≈ 110-240 per pixel) Keck/HIRES spectra for our solar twin candidate, the previously known solar twin HD 45184, and the Sun (using reflected light from the asteroid Vesta). Results: For the bright solar twin HD 45184, we found Teff = 5864 ± 9 K, log g = 4.45 ± 0.03 dex, vt = 1.11 ± 0.02 km s-1, and [Fe/H] = 0.04 ± 0.01 dex, which are in good agreement with previous works. Our abundances are in excellent agreement with a recent high-precision work, with an element-to-element scatter of only 0.01 dex. The star Inti 1 has atmospheric parameters Teff = 5837 ± 11 K, log g = 4.42 ± 0.03 dex, vt = 1.04 ± 0.02 km s-1, and [Fe/H] = 0.07 ± 0.01 dex that are higher than solar. The age and mass of the solar twin HD 45184 (3 Gyr and 1.05 M⊙) and the faint solar twin Inti 1 (4 Gyr and 1.04 M⊙) were estimated using isochrones. The differential analysis shows that HD 45184 presents an abundance pattern that is similar to typical nearby solar twins; this means this star has an enhanced refractory relative to volatile elements, while Inti 1 has an abundance pattern closer to solar, albeit somewhat enhanced in refractories. The abundance

    19. Serendipitous discovery of the faint solar twin Inti 1

      NASA Astrophysics Data System (ADS)

      Galarza, Jhon Yana; Meléndez, Jorge; Cohen, Judith G.

      2016-05-01

      Context. Solar twins are increasingly the subject of many studies owing to their wide range of applications from testing stellar evolution models to the calibration of fundamental observables; these stars are also of interest because high precision abundances could be achieved that are key to investigating the chemical anomalies imprinted by planet formation. Furthermore, the advent of photometric surveys with large telescopes motivates the identification of faint solar twins in order to set the zero point of fundamental calibrations. Aims: We intend to perform a detailed line-by-line differential analysis to verify whether 2MASS J23263267-0239363 (designated here as Inti 1) is indeed a solar twin. Methods: We determine the atmospheric parameters and differential abundances using high-resolution (R ≈ 50 000), high signal-to-noise (S/N ≈ 110-240 per pixel) Keck/HIRES spectra for our solar twin candidate, the previously known solar twin HD 45184, and the Sun (using reflected light from the asteroid Vesta). Results: For the bright solar twin HD 45184, we found Teff = 5864 ± 9 K, log g = 4.45 ± 0.03 dex, vt = 1.11 ± 0.02 km s-1, and [Fe/H] = 0.04 ± 0.01 dex, which are in good agreement with previous works. Our abundances are in excellent agreement with a recent high-precision work, with an element-to-element scatter of only 0.01 dex. The star Inti 1 has atmospheric parameters Teff = 5837 ± 11 K, log g = 4.42 ± 0.03 dex, vt = 1.04 ± 0.02 km s-1, and [Fe/H] = 0.07 ± 0.01 dex that are higher than solar. The age and mass of the solar twin HD 45184 (3 Gyr and 1.05 M⊙) and the faint solar twin Inti 1 (4 Gyr and 1.04 M⊙) were estimated using isochrones. The differential analysis shows that HD 45184 presents an abundance pattern that is similar to typical nearby solar twins; this means this star has an enhanced refractory relative to volatile elements, while Inti 1 has an abundance pattern closer to solar, albeit somewhat enhanced in refractories. The abundance

    20. An infrared study of the bi-polar outflow region GGD 12-15

      NASA Technical Reports Server (NTRS)

      Harvey, P. M.; Wilking, B. A.; Joy, M.; Lester, D. F.

      1984-01-01

      Infrared observations from 1 to 100 microns are presented for the region associated with a bipolar CO outflow source near the nebulous objects GGD 12 to 15. A luminous far-infrared source was found associated with a radio-continuum source in the area. This object appears to be a compact HII region around a nearly main-sequence BO star. A faint 20 micron source was also discovered at the position of an H2O maser 3O deg northwest of the HII region. This object appears to be associated with but not coincident with a 2 micron reflection nebula. This structure serves as evidence for a non-spherically symmetric, possibly disk-like dust distribution around the exciting star for the maser. This object probably powers the bi-polar CO outflow although its luminosity is less than 10% that of the star which excites the compact HII region. A number of other 2 micron sources found in the area are probably members of a recently formed cluster.

    1. Discovery of a long-lived, high-amplitude dusty infrared transient

      NASA Astrophysics Data System (ADS)

      Britt, C. T.; Maccarone, T. J.; Green, J. D.; Jonker, P. G.; Hynes, R. I.; Torres, M. A. P.; Strader, J.; Chomiuk, L.; Salinas, R.; Lucas, P.; Contreras Peña, C.; Kurtev, R.; Heinke, C.; Smith, L.; Wright, N. J.; Johnson, C.; Steeghs, D.; Nelemans, G.

      2016-08-01

      We report the detection of an infrared selected transient which has lasted at least 5 years, first identified by a large mid-infrared and optical outburst from a faint X-ray source detected with the Chandra X-ray Observatory. In this paper we rule out several scenarios for the cause of this outburst, including a classical nova, a luminous red nova, AGN flaring, a stellar merger, and intermediate luminosity optical transients, and interpret this transient as the result of a Young Stellar Object (YSO) of at least solar mass accreting material from the remains of the dusty envelope from which it formed, in isolation from either a dense complex of cold gas or massive star formation. This object does not fit neatly into other existing categories of large outbursts of YSOs (FU Orionis types) which may be a result of the object's mass, age, and environment. It is also possible that this object is a new type of transient unrelated to YSOs.

    2. Discovery of a long-lived, high-amplitude dusty infrared transient

      NASA Astrophysics Data System (ADS)

      Britt, C. T.; Maccarone, T. J.; Green, J. D.; Jonker, P. G.; Hynes, R. I.; Torres, M. A. P.; Strader, J.; Chomiuk, L.; Salinas, R.; Lucas, P.; Contreras Peña, C.; Kurtev, R.; Heinke, C.; Smith, L.; Wright, N. J.; Johnson, C.; Steeghs, D.; Nelemans, G.

      2016-08-01

      We report the detection of an infrared-selected transient which has lasted at least five years, first identified by a large mid-infrared and optical outburst from a faint X-ray source detected with the Chandra X-ray Observatory. In this paper we rule out several scenarios for the cause of this outburst, including a classical nova, a luminous red nova, AGN flaring, a stellar merger, and intermediate luminosity optical transients, and interpret this transient as the result of a young stellar object (YSO) of at least solar mass accreting material from the remains of the dusty envelope from which it formed, in isolation from either a dense complex of cold gas or massive star formation. This object does not fit neatly into other existing categories of large outbursts of YSOs (FU Orionis types) which may be a result of the object's mass, age, and environment. It is also possible that this object is a new type of transient unrelated to YSOs.

    3. GPU-accelerated Faint Streak Detection for Uncued Surveillance of LEO

      NASA Astrophysics Data System (ADS)

      Zimmer, P.; Ackermann, M.; McGraw, J. T.

      2013-09-01

      By astronomical standards, small objects (<10cm) in LEO illuminated by the Sun under terminator conditions are quite bright, depositing 100's to 1000's of photons per second into small telescope apertures (< 1m diameter). The challenge in discovering these objects with no a priori knowledge of their orbit (i.e. uncued surveillance) is that their relative motion with respect to a ground-based telescope makes them appear to have large angular rates of motion, up to and exceeding 1 degree per second. Thus in even a short exposure, the signal from the object is smeared out in a streak with low signal-to-noise per pixel. Go Green Termite (GGT), Inc. of Gilroy, CA, in collaboration with the University of New Mexico (UNM), is building two proof-of-concept wide-field imaging systems to test, develop and prove a novel streak detection technique. The imaging systems are built from off-the-shelf optics and detectors resulting in a 350mm aperture and a 6 square degree field of view. For streak detection, field of view is of critical importance because the maximum exposure time on the object is limited by its crossing time. In this way, wider fields of view impact surveys for LEO objects both by increasing the survey volume and increasing sensitivity. Using our newly GPU-accelerated detection scheme, the proof-of-concept systems are expected to be able to detect objects fainter than 12th magnitude moving at 1 degree per second and possibly as faint as 13th magnitude for slower moving objects. Meter-class optical systems using these techniques should be able to detect objects fainter than 14th magnitude, which is roughly equivalent to a golf ball at 1000km altitude. The goal of this work is to demonstrate a scalable system for near real time detection of fast moving objects that can be then handed off to other instruments capable of tracking and characterizing them. The two proof-of-concept systems, separated by ~30km, work together by taking simultaneous images of the same

    4. Helium shells and faint emission lines from slitless flash spectra

      NASA Astrophysics Data System (ADS)

      Bazin, Cyril; Koutchmy, Serge

      2013-05-01

      At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence.

    5. Carbon Dioxide Cycling, Climate, Impacts, and the Faint Young Sun

      NASA Technical Reports Server (NTRS)

      Zahnle, K. J.; Sleep, H. H.

      1999-01-01

      Evidence for relatively mild climates on ancient Earth and Mars has been a puzzle in light of the faint early sun. The geologic evidence, although far from conclusive, would appear to indicate that the surfaces of both planets were, if anything, warmer ca. 3-4 Ga than they are now. The astrophysical argument that the sun ought to have brightened approx. 30% since it reached the main sequence is hard to refute. There results a paradox between the icehouse we expect and the greenhouse we think we see. The usual fix has been to posit massive CO2 atmospheres, although reduced gases (e.g., NH3 or CH4 ) have had their partisans. Evidence against siderite in paleosols dated 2.2-2.75 Ga sets a rough upper limit of 30 PAL (present atmospheric levels) on pCO2 at that time. This is an order of magnitude short of what is needed to defeat the fainter sun. We present here an independent argument against high pCO2 on early Earth that applies not only to the Archean but yet more forcefully to the Hadean era. Additional information is contained in the original extended abstract.

    6. Luminosity Function of Faint Globular Clusters in M87

      SciTech Connect

      Waters, Christopher Z.; Zepf, Stephen E.; Lauer, Tod R.; Baltz, Edward A.; Silk, Joseph; /Oxford U.

      2006-07-14

      We present the luminosity function to very faint magnitudes for the globular clusters in M87, based on a 30 orbit Hubble Space Telescope (HST) WFPC2 imaging program. The very deep images and corresponding improved false source rejection allow us to probe the mass function further beyond the turnover than has been done before. We compare our luminosity function to those that have been observed in the past, and confirm the similarity of the turnover luminosity between M87 and the Milky Way. We also find with high statistical significance that the M87 luminosity function is broader than that of the Milky Way. We discuss how determining the mass function of the cluster system to low masses can constrain theoretical models of the dynamical evolution of globular cluster systems. Our mass function is consistent with the dependence of mass loss on the initial cluster mass given by classical evaporation, and somewhat inconsistent with newer proposals that have a shallower mass dependence. In addition, the rate of mass loss is consistent with standard evaporation models, and not with the much higher rates proposed by some recent studies of very young cluster systems. We also find that the mass-size relation has very little slope, indicating that there is almost no increase in the size of a cluster with increasing mass.

    7. Helium shells and faint emission lines from slitless flash spectra

      PubMed Central

      Bazin, Cyril; Koutchmy, Serge

      2013-01-01

      At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence. PMID:25685435

    8. THE PRIMEVAL POPULATIONS OF THE ULTRA-FAINT DWARF GALAXIES

      SciTech Connect

      Brown, Thomas M.; Tumlinson, Jason; Kalirai, Jason S.; Avila, Roberto J.; Ferguson, Henry C. E-mail: tumlinson@stsci.edu E-mail: avila@stsci.edu; and others

      2012-07-01

      We present new constraints on the star formation histories of the ultra-faint dwarf (UFD) galaxies, using deep photometry obtained with the Hubble Space Telescope (HST). A galaxy class recently discovered in the Sloan Digital Sky Survey, the UFDs appear to be an extension of the classical dwarf spheroidals to low luminosities, offering a new front in efforts to understand the missing satellite problem. They are the least luminous, most dark-matter-dominated, and least chemically evolved galaxies known. Our HST survey of six UFDs seeks to determine if these galaxies are true fossils from the early universe. We present here the preliminary analysis of three UFD galaxies: Hercules, Leo IV, and Ursa Major I. Classical dwarf spheroidals of the Local Group exhibit extended star formation histories, but these three Milky Way satellites are at least as old as the ancient globular cluster M92, with no evidence for intermediate-age populations. Their ages also appear to be synchronized to within {approx}1 Gyr of each other, as might be expected if their star formation was truncated by a global event, such as reionization.

    9. No climate paradox under the faint early Sun.

      PubMed

      Rosing, Minik T; Bird, Dennis K; Sleep, Norman H; Bjerrum, Christian J

      2010-04-01

      Environmental niches in which life first emerged and later evolved on the Earth have undergone dramatic changes in response to evolving tectonic/geochemical cycles and to biologic interventions, as well as increases in the Sun's luminosity of about 25 to 30 per cent over the Earth's history. It has been inferred that the greenhouse effect of atmospheric CO(2) and/or CH(4) compensated for the lower solar luminosity and dictated an Archaean climate in which liquid water was stable in the hydrosphere. Here we demonstrate, however, that the mineralogy of Archaean sediments, particularly the ubiquitous presence of mixed-valence Fe(II-III) oxides (magnetite) in banded iron formations is inconsistent with such high concentrations of greenhouse gases and the metabolic constraints of extant methanogens. Prompted by this, and the absence of geologic evidence for very high greenhouse-gas concentrations, we hypothesize that a lower albedo on the Earth, owing to considerably less continental area and to the lack of biologically induced cloud condensation nuclei, made an important contribution to moderating surface temperature in the Archaean eon. Our model calculations suggest that the lower albedo of the early Earth provided environmental conditions above the freezing point of water, thus alleviating the need for extreme greenhouse-gas concentrations to satisfy the faint early Sun paradox. PMID:20360739

    10. ARE THE ULTRA-FAINT DWARF GALAXIES JUST CUSPS?

      SciTech Connect

      Zolotov, Adi; Hogg, David W.; Willman, Beth

      2011-01-20

      We develop a technique to investigate the possibility that some of the recently discovered ultra-faint dwarf satellites of the Milky Way might be cusp caustics rather than gravitationally self-bound systems. Such cusps can form when a stream of stars folds, creating a region where the projected two-dimensional surface density is enhanced. In this work, we construct a Poisson maximum likelihood test to compare the cusp and exponential models of any substructure on an equal footing. We apply the test to the Hercules dwarf (d {approx} 113 kpc, M{sub V} {approx} -6.2, e {approx} 0.67). The flattened exponential model is strongly favored over the cusp model in the case of Hercules, ruling out at high confidence that Hercules is a cusp catastrophe. This test can be applied to any of the Milky Way dwarfs, and more generally to the entire stellar halo population, to search for the cusp catastrophes that might be expected in an accreted stellar halo.

    11. Helium shells and faint emission lines from slitless flash spectra.

      PubMed

      Bazin, Cyril; Koutchmy, Serge

      2013-05-01

      At the time of the two last solar total eclipses of August 1st, 2008 in Siberia and July 11th, 2010 in French Polynesia, high frame rate CCD flash spectra were obtained. These eclipses occurred in quiet Sun period and after. The slitless flash spectra show two helium shells, in the weak Paschen α 4686 Å line of the ionized helium HeII and in the neutral helium HeI line at 4713 Å. The extensions of these helium shells are typically 3 Mm. In prominences, the extension of the interface with the corona is much more extended. The observations and analysis of these lines can properly be done only in eclipse conditions, when the intensity threshold reaches the coronal level, and the parasitic scattered light is virtually zero. Under the layers of 1 Mm above the limb, many faint low FIP lines were also seen in emission. These emission lines are superposed on the continuum containing absorption lines. The solar limb can be defined using the weak continuum appearing between the emission lines at the time of the second and third contact. The variations of the singly ionized iron line, the HeI and HeII lines and the continuum intensity are analyzed. The intensity ratio of ionized to neutral helium is studied for evaluating the ionization rate in low layers up to 2 Mm and also around a prominence. PMID:25685435

    12. Abundance ratios of red giants in low-mass ultra-faint dwarf spheroidal galaxies

      NASA Astrophysics Data System (ADS)

      François, P.; Monaco, L.; Bonifacio, P.; Moni Bidin, C.; Geisler, D.; Sbordone, L.

      2016-04-01

      Context. Low-mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their star formation and chemical evolution. Aims: We report on the analysis of a sample of 11 stars belonging to five different ultra-faint dwarf spheroidal galaxies (UfDSph) that is based on X-Shooter spectra obtained at the VLT. Methods: Medium-resolution spectra have been used to determine the detailed chemical composition of their atmosphere. We performed a standard 1D LTE analysis to compute the abundances. Results: Considering all the stars as representative of the same population of low-mass galaxies, we found that the [α/Fe] ratios vs.s [Fe/H] decreases as the metallicity of the star increases in a way similar to that which is found for the population of stars that belong to dwarf spheroidal galaxies. The main difference is that the solar [α/Fe] is reached at a much lower metallicity for the UfDSph than for the dwarf spheroidal galaxies. We report for the first time the abundance of strontium in CVn II. The star we analyzed in this galaxy has a very high [Sr/Fe] and a very low upper limit of barium which makes it a star with an exceptionally high [Sr/Ba] ratio.

    13. Infrared Investigations.

      ERIC Educational Resources Information Center

      Lascours, Jean; Albe, Virginie

      2001-01-01

      Describes a series of simple and nontraditional experiments that enable students to discover the properties of infrared radiation by studying the propagation, reflection, diffusion, and refraction of infrared. The experiments rely on two modules, an infrared transmitter and an infrared receiver. (SAH)

    14. A WISE Census of Young Stellar Objects in Canis Major

      NASA Astrophysics Data System (ADS)

      Fischer, William J.; Padgett, Deborah L.; Stapelfeldt, Karl L.; Sewiło, Marta

      2016-08-01

      With the Wide-field Infrared Survey Explorer (WISE), we searched for young stellar objects (YSOs) in a 100 deg2 region centered on the lightly studied Canis Major star-forming region. Applying stringent magnitude cuts to exclude the majority of extragalactic contaminants, we find 144 Class I candidates and 335 Class II candidates. The sensitivity to Class II candidates is limited by their faintness at the distance to Canis Major (assumed as 1000 pc). More than half the candidates (53%) are found in 16 groups of more than four members, including four groups with more than 25 members each. The ratio of Class II to Class I objects, N II/N I, varies from 0.4 to 8.3 in just the largest four groups. We compare our results to those obtainable with combined Two Micron All Sky Survey and post-cryogenic Spitzer Space Telescope data; the latter approach recovers missing Class II sources. Via a comparison to protostars characterized with the Herschel Space Observatory, we propose new WISE color criteria for flat-spectrum and Class 0 protostars, finding 80 and 7 of these, respectively. The distribution of YSOs in CMa OB1 is consistent with supernova-induced star formation, although the diverse N II/N I ratios are unexpected if this parameter traces age and the YSOs are due to the same supernova. Less massive clouds feature larger N II/N I ratios, suggesting that initial conditions play a role in determining this quantity.

    15. Star formation rate and extinction in faint z ∼ 4 Lyman break galaxies

      SciTech Connect

      To, Chun-Hao; Wang, Wei-Hao; Owen, Frazer N.

      2014-09-10

      We present a statistical detection of 1.5 GHz radio continuum emission from a sample of faint z ∼ 4 Lyman break galaxies (LBGs). To constrain their extinction and intrinsic star formation rate (SFR), we combine the latest ultradeep Very Large Array 1.5 GHz radio image and the Hubble Space Telescope Advanced Camera for Surveys (ACS) optical images in the GOODS-N. We select a large sample of 1771 z ∼ 4 LBGs from the ACS catalog using B {sub F435W}-dropout color criteria. Our LBG samples have I {sub F775W} ∼ 25-28 (AB), ∼0-3 mag fainter than M{sub UV}{sup ⋆} at z ∼ 4. In our stacked radio images, we find the LBGs to be point-like under our 2'' angular resolution. We measure their mean 1.5 GHz flux by stacking the measurements on the individual objects. We achieve a statistical detection of S {sub 1.5} {sub GHz} = 0.210 ± 0.075 μJy at ∼3σ for the first time on such a faint LBG population at z ∼ 4. The measurement takes into account the effects of source size and blending of multiple objects. The detection is visually confirmed by stacking the radio images of the LBGs, and the uncertainty is quantified with Monte Carlo simulations on the radio image. The stacked radio flux corresponds to an obscured SFR of 16.0 ± 5.7 M {sub ☉} yr{sup –1}, and implies a rest-frame UV extinction correction factor of 3.8. This extinction correction is in excellent agreement with that derived from the observed UV continuum spectral slope, using the local calibration of Meurer et al. This result supports the use of the local calibration on high-redshift LBGs to derive the extinction correction and SFR, and also disfavors a steep reddening curve such as that of the Small Magellanic Cloud.

    16. Evolution of faint radio sources in the VIDEO-XMM3 field

      NASA Astrophysics Data System (ADS)

      McAlpine, K.; Jarvis, M. J.; Bonfield, D. G.

      2013-12-01

      It has been speculated that low-luminosity radio-loud active galactic nuclei (AGN) have the potential to serve as an important source of AGN feedback, and may be responsible for suppressing star formation activity in massive elliptical galaxies at late times. As such the cosmic evolution of these sources is vitally important to understand the significance of such AGN feedback processes and their influence on the global star formation history of the Universe. In this paper, we present a new investigation of the evolution of faint radio sources out to z ˜ 2.5. We combine a 1 square degree Very Large Array radio survey, complete to a depth of 100 μJy, with accurate 10 band photometric redshifts from the following surveys: Visible and Infrared Survey Telescope for Astronomy Deep Extragalactic Observations and Canada-France-Hawaii Telescope Legacy Survey. The results indicate that the radio population experiences mild positive evolution out to z ˜ 1.2 increasing their space density by a factor of ˜3, consistent with results of several previous studies. Beyond z = 1.2, there is evidence of a slowing down of this evolution. Star-forming galaxies drive the more rapid evolution at low redshifts, z < 1.2, while more slowly evolving AGN populations dominate at higher redshifts resulting in a decline in the evolution of the radio luminosity function at z > 1.2. The evolution is best fitted by pure luminosity evolution with star-forming galaxies evolving as (1 + z)2.47 ± 0.12 and AGN as (1 + z)1.18 ± 0.21.

    17. On the Morphology of the HST Faint Galaxies

      NASA Astrophysics Data System (ADS)

      Giavalisco, Mauro; Livio, Mario; Bohlin, Ralph C.; Macchetto, F. Duccio; Stecher, Theodore P.

      1996-08-01

      Deep imaging with the Hubble Space Telescope (HST) has revealed a population of rapidly evolving galaxies, which account for < 50% of the total counts at I <~ 22.5, are well distinct from the passively evolving normal ellipticals and spirals, and have morphologies that elude the traditional Hubble classification scheme. This classification has been derived from the morphological properties of local galaxies observed at optical wavelengths. Since galaxy morphology is a function of the wavelength and of the localization and intensity of the star-formation activity, the appearance of galaxies at large redshifts is subject to k- correction and evolutionary effects of the stellar populations, even if the underlying dynamics does not change significantly. In addition, the strong dependence of the surface brightness on redshift as σ ~(1 +z)^-4^ implies that the observed morphology of distant galaxies is also affected by the limiting surface brightness that can be reached. This paper shows how local galaxies observed at UV wavelengths with the Ultraviolet Imaging Telescope (UIT) would appear to HST if placed at cosmological distances, with the UV light redshifted to the optical wavelengths. The simulated distant galaxies have morphologies that are of later type or more irregular than their local (optical) counterparts, and some are in qualitative agreement with those revealed by the faint HST surveys, suggesting that dynamical evolution has played a minor role in the evolution of the majority of the galaxies over a large fraction of the Hubble time. However, the dependence of galaxy morphology on the star-formation activity and on the wavelength must be properly understood before any conclusion on the overall morphological evolution of galaxies can be derived.

    18. Near-infrared Thermal Emission Detections of a Number of Hot Jupiters and the Systematics of Ground-based Near-infrared Photometry

      NASA Astrophysics Data System (ADS)

      Croll, Bryce; Albert, Loic; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Lafreniere, David; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

      2015-03-01

      We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K CONT-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations. Based on observations obtained with WIRCam, a joint project of Canada-France-Hawaii Telescope (CFHT), Taiwan, Korea, Canada, France, at the CFHT, which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

    19. The Spectroscopic Properties of Lyα-Emitters at z ˜2.7: Escaping Gas and Photons from Faint Galaxies

      NASA Astrophysics Data System (ADS)

      Trainor, Ryan F.; Steidel, Charles C.; Strom, Allison L.; Rudie, Gwen C.

      2015-08-01

      We present a spectroscopic survey of 318 faint ({R}˜ 27, L˜ 0.1{L}*), Lyα-emission-selected galaxies (LAEs) in regions centered on the positions of hyperluminous QSOs (HLQSOs) at 2.5\\lt z\\lt 3. A sample of 32 LAEs with rest-frame optical emission line spectra from Keck/Multi-Object Spectrometer For InfraRed Exploration (MOSFIRE) are used to interpret the LAE spectra in the context of their systemic redshifts. The fields are part of the Keck Baryonic Structure Survey, which includes substantial ancillary multi-wavelength imaging from both the ground and space. From a quantitative analysis of the diverse Lyα spectral morphologies, including line widths, asymmetries, and multi-peaked profiles, we find that peak widths and separations are typically smaller than among samples of more luminous continuum-selected galaxies (Lyman-break galaxies and their analogs; LBGs) at similar redshifts. We find tentative evidence for an association between Lyα spectral morphology and external illumination by the nearby HLQSO. Using the MOSFIRE subsample, we find that the peak of the resolved (R ≈ 1300) Lyα line is shifted by +200 km s-1 with respect to systemic across a diverse set of galaxies including both LAEs and LBGs. We also find a small number of objects with significantly blueshifted Lyα emission, a potential indicator of accreting gas. The Lyα-to-Hα line ratios measured for the MOSFIRE subset suggest that the LAEs in this sample have Lyα escape fractions {f}{esc,{Ly}α } ≈ 30%, significantly higher than typical LBG samples. Using redshifts calibrated by our MOSFIRE sample, we construct composite LAE spectra, finding the first evidence for metal-enriched outflows in such intrinsically faint high-redshift galaxies. These outflows have smaller continuum covering fractions ({f}{{c}}≈ 0.3) and velocities ({v}{ave} ≈ 100-200 km s-1, {v}{max} ≈ 500 km s-1) than those associated with typical LBGs, suggesting that the gas covering fraction is a likely driver of

    20. Infrared spectrum of an extremely cool white-dwarf star

      PubMed

      Hodgkin; Oppenheimer; Hambly; Jameson; Smartt; Steele

      2000-01-01

      White dwarfs are the remnant cores of stars that initially had masses of less than 8 solar masses. They cool gradually over billions of years, and have been suggested to make up much of the 'dark matter' in the halo of the Milky Way. But extremely cool white dwarfs have proved difficult to detect, owing to both their faintness and their anticipated similarity in colour to other classes of dwarf stars. Recent improved models indicate that white dwarfs are much more blue than previously supposed, suggesting that the earlier searches may have been looking for the wrong kinds of objects. Here we report an infrared spectrum of an extremely cool white dwarf that is consistent with the new models. We determine the star's temperature to be 3,500 +/- 200 K, making it the coolest known white dwarf. The kinematics of this star indicate that it is in the halo of the Milky Way, and the density of such objects implied by the serendipitous discovery of this star is consistent with white dwarfs dominating the dark matter in the halo. PMID:10638748

    1. Adaptive Optics Imaging Survey of Luminous Infrared Galaxies

      SciTech Connect

      Laag, E A; Canalizo, G; van Breugel, W; Gates, E L; de Vries, W; Stanford, S A

      2006-03-13

      We present high resolution imaging observations of a sample of previously unidentified far-infrared galaxies at z < 0.3. The objects were selected by cross-correlating the IRAS Faint Source Catalog with the VLA FIRST catalog and the HST Guide Star Catalog to allow for adaptive optics observations. We found two new ULIGs (with L{sub FIR} {ge} 10{sup 12} L{sub {circle_dot}}) and 19 new LIGs (with L{sub FIR} {ge} 10{sup 11} L{sub {circle_dot}}). Twenty of the galaxies in the sample were imaged with either the Lick or Keck adaptive optics systems in H or K{prime}. Galaxy morphologies were determined using the two dimensional fitting program GALFIT and the residuals examined to look for interesting structure. The morphologies reveal that at least 30% are involved in tidal interactions, with 20% being clear mergers. An additional 50% show signs of possible interaction. Line ratios were used to determine powering mechanism; of the 17 objects in the sample showing clear emission lines--four are active galactic nuclei and seven are starburst galaxies. The rest exhibit a combination of both phenomena.

    2. Near-infrared counterparts to the Galactic Bulge Survey X-ray source population

      NASA Astrophysics Data System (ADS)

      Greiss, S.; Steeghs, D.; Jonker, P. G.; Torres, M. A. P.; Maccarone, T. J.; Hynes, R. I.; Britt, C. T.; Nelemans, G.; Gänsicke, B. T.

      2014-03-01

      We report on the near-infrared matches, drawn from three surveys, to the 1640 unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS). This survey targets faint X-ray sources in the bulge, with a particular focus on accreting compact objects. We present all viable counterpart candidates and associate a false alarm probability (FAP) to each near-infrared match in order to identify the most likely counterparts. The FAP takes into account a statistical study involving a chance alignment test, as well as considering the positional accuracy of the individual X-ray sources. We find that although the star density in the bulge is very high, ˜90 per cent of our sources have an FAP <10 per cent, indicating that for most X-ray sources, viable near-infrared counterparts candidates can be identified. In addition to the FAP, we provide positional and photometric information for candidate counterparts to ˜95 per cent of the GBS X-ray sources. This information in combination with optical photometry, spectroscopy and variability constraints will be crucial to characterize and classify secure counterparts.

    3. The Quenching of the Ultra-faint Dwarf Galaxies in the Reionization Era

      NASA Astrophysics Data System (ADS)

      Brown, Thomas M.; Tumlinson, Jason; Geha, Marla; Simon, Joshua D.; Vargas, Luis C.; VandenBerg, Don A.; Kirby, Evan N.; Kalirai, Jason S.; Avila, Roberto J.; Gennaro, Mario; Ferguson, Henry C.; Muñoz, Ricardo R.; Guhathakurta, Puragra; Renzini, Alvio

      2014-12-01

      We present new constraints on the star formation histories of six ultra-faint dwarf galaxies: Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV, and Ursa Major I. Our analysis employs a combination of high-precision photometry obtained with the Advanced Camera for Surveys on the Hubble Space Telescope, medium-resolution spectroscopy obtained with the DEep Imaging Multi-Object Spectrograph on the W. M. Keck Observatory, and updated Victoria-Regina isochrones tailored to the abundance patterns appropriate for these galaxies. The data for five of these Milky Way satellites are best fit by a star formation history where at least 75% of the stars formed by z ~ 10 (13.3 Gyr ago). All of the galaxies are consistent with 80% of the stars forming by z ~ 6 (12.8 Gyr ago) and 100% of the stars forming by z ~ 3 (11.6 Gyr ago). The similarly ancient populations of these galaxies support the hypothesis that star formation in the smallest dark-matter sub-halos was suppressed by a global outside influence, such as the reionization of the universe. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-12549.

    4. The quenching of the ultra-faint dwarf galaxies in the reionization era

      SciTech Connect

      Brown, Thomas M.; Tumlinson, Jason; Kalirai, Jason S.; Avila, Roberto J.; Gennaro, Mario; Ferguson, Henry C. E-mail: tumlinson@stsci.edu E-mail: avila@stsci.edu E-mail: gennaro@stsci.edu; and others

      2014-12-01

      We present new constraints on the star formation histories of six ultra-faint dwarf galaxies: Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV, and Ursa Major I. Our analysis employs a combination of high-precision photometry obtained with the Advanced Camera for Surveys on the Hubble Space Telescope, medium-resolution spectroscopy obtained with the DEep Imaging Multi-Object Spectrograph on the W. M. Keck Observatory, and updated Victoria-Regina isochrones tailored to the abundance patterns appropriate for these galaxies. The data for five of these Milky Way satellites are best fit by a star formation history where at least 75% of the stars formed by z ∼ 10 (13.3 Gyr ago). All of the galaxies are consistent with 80% of the stars forming by z ∼ 6 (12.8 Gyr ago) and 100% of the stars forming by z ∼ 3 (11.6 Gyr ago). The similarly ancient populations of these galaxies support the hypothesis that star formation in the smallest dark-matter sub-halos was suppressed by a global outside influence, such as the reionization of the universe.

    5. Probing the Peak Epoch of Cosmic Star Formation (1Faint Star-forming Galaxies Behind the Lensing Clusters: UV Luminosity Function and the Dust Attenuation

      NASA Astrophysics Data System (ADS)

      Alavi, Anahita; Siana, Brian D.; Richard, Johan; Rafelski, Marc; Jauzac, Mathilde; Limousin, Marceau; Stark, Daniel; Teplitz, Harry I.

      2016-01-01

      Obtaining a complete census of cosmic star formation requires an understanding of faint star-forming galaxies that are far below the detection limits of current surveys. To search for the faint galaxies, we use the power of strong gravitational lensing from foreground galaxy clusters to boost the detection limits of HST to much fainter luminosities. Using the WFC3/UVIS on board the HST, we obtain deep UV images of 4 lensing clusters with existing deep optical and near-infrared data (three from Frontier Fields survey). Building multiband photometric catalogs and applying a photometric redshift selection, we uncover a large population of dwarf galaxies (-18.5faint magnitudes (MUV=-12.5). As an important implication of a steep faint-end slope LF, we show that the faint galaxies (-18.550%) at these redshifts. We use this unique sample to investigate further the various properties of dwarf galaxies as it is claimed to deviate from the trends seen for the more massive galaxies. Recent hydro-dynamical simulations and observations of local dwarfs show that these galaxies have episodic bursts of star formation on short time scales (< 10 Myr). We find that the bursty star formation histories (SFHs) cause a large intrinsic scatter in UV colors (β) at MUV > -16, comparing a sample of low mass galaxies from simulations with bursty SFHs with our comprehensive measurements of the observed β values. As this scatter can also be due to the dust extinction, we distinguish these two effects by measuring the dust attenuation using Balmer decrement (Hα/Hβ) ratios from our MOSFIRE/Keck spectroscopy.

    6. Time series photometry of faint cataclysmic variables with a CCD

      NASA Astrophysics Data System (ADS)

      Abbott, Timothy Mark Cameron

      1992-08-01

      I describe a new hardware and software environment for the practice of time-series stellar photometry with the CCD systems available at McDonald Observatory. This instrument runs suitable CCD's in frame transfer mode and permits windowing on the CCD image to maximize the duty cycle of the photometer. Light curves may be extracted and analyzed in real time at the telescope and image data are stored for later, more thorough analysis. I describe a star tracking algorithm, which is optimized for a timeseries of images of the same stellar field. I explore the extraction of stellar brightness measures from these images using circular software apertures and develop a complete description of the noise properties of this technique. I show that scintillation and pixelization noise have a significant effect on high quality observations. I demonstrate that optimal sampling and profile fitting techniques are unnecessarily complex or detrimental methods of obtaining stellar brightness measures under conditions commonly encountered in timeseries CCD photometry. I compare CCD's and photomultiplier tubes as detectors for timeseries photometry using light curves of a variety of stars obtained simultaneously with both detectors and under equivalent conditions. A CCD can produce useful data under conditions when a photomultiplier tube cannot, and a CCD will often produce more reliable results even under photometric conditions. I prevent studies of the cataclysmic variables (CV's) AL Com, CP Eri, V Per, and DO Leo made using the time series CCD photometer. AL Com is a very faint CV at high Galactic latitude and a bona fide Population II CV. Some of the properties of AL Com are similar to the dwarf nova WZ Sge and others are similar to the intermediate polar EX Hya, but overall AL Com is unlike any other well-studied cataclysmic variable. CP Eri is shown to be the fifth known interacting binary white dwarf. V Per was the first CV found to have an orbital period near the middle of the

    7. Spitzer ultra faint survey program (surfs up). I. An overview

      SciTech Connect

      Bradač, Maruša; Huang, Kuang-Han; Cain, Benjamin; Hall, Nicholas; Lubin, Lori; Ryan, Russell; Casertano, Stefano; Lemaux, Brian C.; Schrabback, Tim; Hildebrandt, Hendrik; Gonzalez, Anthony H.; Allen, Steve; Von der Linden, Anja; Gladders, Mike; Hinz, Joannah; Zaritsky, Dennis; Treu, Tommaso

      2014-04-20

      Spitzer UltRa Faint SUrvey Program is a joint Spitzer and Hubble Space Telescope Exploration Science program using 10 galaxy clusters as cosmic telescopes to study z ≳ 7 galaxies at intrinsically lower luminosities, enabled by gravitational lensing, than blank field surveys of the same exposure time. Our main goal is to measure stellar masses and ages of these galaxies, which are the most likely sources of the ionizing photons that drive reionization. Accurate knowledge of the star formation density and star formation history at this epoch is necessary to determine whether these galaxies indeed reionized the universe. Determination of the stellar masses and ages requires measuring rest-frame optical light, which only Spitzer can probe for sources at z ≳ 7, for a large enough sample of typical galaxies. Our program consists of 550 hr of Spitzer/IRAC imaging covering 10 galaxy clusters with very well-known mass distributions, making them extremely precise cosmic telescopes. We combine our data with archival observations to obtain mosaics with ∼30 hr exposure time in both 3.6 μm and 4.5 μm in the central 4' × 4' field and ∼15 hr in the flanking fields. This results in 3σ sensitivity limits of ∼26.6 and ∼26.2 AB magnitudes for the central field in the IRAC 3.6 and 4.5 μm bands, respectively. To illustrate the survey strategy and characteristics we introduce the sample, present the details of the data reduction and demonstrate that these data are sufficient for in-depth studies of z ≳ 7 sources (using a z = 9.5 galaxy behind MACS J1149.5+2223 as an example). For the first cluster of the survey (the Bullet Cluster) we have released all high-level data mosaics and IRAC empirical point-spread function models. In the future we plan to release these data products for the entire survey.

    8. Near-infrared images of MG 1131+0456 with the W. M. Keck telescope: Another dusty gravitational lens?

      NASA Technical Reports Server (NTRS)

      Larkin, J. E.; Matthews, K.; Lawrence, C. R.; Graham, J. R.; Harrison, W.; Jernigan, G.; Lin, S.; Nelson, J.; Neugebauer, G.; Smith, G.

      1994-01-01

      Images of the gravitational lens system MG 1131+0456 taken with the near-infrared camera on the W. M. Keck telescope in the J and K(sub s) bands show that the infrared counterparts of the compact radio structure are exceedingly red, with J - K greater than 4.2 mag. The J image reveals only the lensing galaxy, while the K(sub s) image shows both the lens and the infrared counterparts of the compact radio components. After subtracting the lensing galaxy from the K(sub s) image, the position and orientation of the compact components agree with their radio counterparts. The broad-band spectrum and observed brightness of the lens suggest a giant galaxy at a redshift of approximately 0.75, while the color of the quasar images suggests significant extinction by dust in the lens. There is a significant excess of faint objects within 20 sec of MG 1131+0456. Depending on their mass and redshifts, these objects could complicate the lensing potential considerably.

    9. Infrared thermography

      SciTech Connect

      Roberts, C.C. Jr.

      1982-12-01

      Infrared thermography is a useful tool for the diagnosis of problems in building systems. In instances where a building owner has several large buildings, an investment in a typical $30,000 infrared system may be cost effective. In most instances, however, the rental of an infrared system or the hiring of an infrared consulting service is a cost effective alternative. As can be seen from the several applications presented here, any mechanical problem manifesting itself in an atypical temperature pattern can usually be detected. The two primary savings generated from infrared analysis of building systems are maintenance and energy.

    10. Searching for Faint Exozodiacal Disks: Keck Results and LBTI Status

      NASA Astrophysics Data System (ADS)

      Defrère, D.; Hinz, P.; Mennesson, B.; Millan-Gabet, R.; Skemer, A.; Bailey, V.; Rodigas, T. J.

      2014-01-01

      The possible presence of dust in the habitable zone around nearby main-sequence stars is considered as a major hurdle toward the direct imaging of Earth-like extrasolar planets with future dedicated space-based telescopes (e.g., Roberge et al. 2012). In this context, NASA has funded two ground-based mid-infrared nulling interferometers to combine the large apertures available at the Keck Observatory and the Large Binocular Telescope (LBT). In this poster, we present the preliminary results of the extended survey carried out with the Keck Interferometer Nuller (KIN) between 2008 and 2011 and describe the forthcoming LBTI survey.

    11. MEASURING X-RAY VARIABILITY IN FAINT/SPARSELY SAMPLED ACTIVE GALACTIC NUCLEI

      SciTech Connect

      Allevato, V.; Paolillo, M.; Papadakis, I.; Pinto, C.

      2013-07-01

      We study the statistical properties of the normalized excess variance of variability process characterized by a ''red-noise'' power spectral density (PSD), as in the case of active galactic nuclei (AGNs). We perform Monte Carlo simulations of light curves, assuming both a continuous and a sparse sampling pattern and various signal-to-noise ratios (S/Ns). We show that the normalized excess variance is a biased estimate of the variance even in the case of continuously sampled light curves. The bias depends on the PSD slope and on the sampling pattern, but not on the S/N. We provide a simple formula to account for the bias, which yields unbiased estimates with an accuracy better than 15%. We show that the normalized excess variance estimates based on single light curves (especially for sparse sampling and S/N < 3) are highly uncertain (even if corrected for bias) and we propose instead the use of an ''ensemble estimate'', based on multiple light curves of the same object, or on the use of light curves of many objects. These estimates have symmetric distributions, known errors, and can also be corrected for biases. We use our results to estimate the ability to measure the intrinsic source variability in current data, and show that they could also be useful in the planning of the observing strategy of future surveys such as those provided by X-ray missions studying distant and/or faint AGN populations and, more in general, in the estimation of the variability amplitude of sources that will result from future surveys such as Pan-STARRS and LSST.

    12. Establishing a Network of faint DA white dwarfs as Spectrophotometric Standards

      NASA Astrophysics Data System (ADS)

      Saha, Abhijit; Narayan, Gautham; Holberg, Jay; Matheson, Thomas; Olszewski, Edward; Stubbs, Christopher; Bohlin, Ralph; Sabbi, Elena; Deustua, Susana; Rest, Armin; Axelrod, Tim; MacKenty, John W.; Camarota, Larry; Gilliland, Ron

      2015-08-01

      Systematic uncertainties in photometric calibration are the dominant source of error in current type Ia supernova dark energy studies, as well as other forefront cosmology efforts, e.g. photo-redshift determinations for weak lensing mass tomography. Current and next-generation ground-based all-sky surveys require a network of calibration stars with 1) known SEDs (to properly and unambiguously take into account filter differences), and 2) that are on a common photometric zeropoint scale across the sky to sub-percent accuracy. We are using a combination of HST panchromatic photometry and ground based spectroscopy to establish such an essential network of faint primary photometric standards, exploiting the well-understood spectral energy distributions of DA white dwarf stars that are free from the complications of observing through the Earth's time-variable atmosphere. The Balmer features in the spectra are used to deduce the two parameters (temperature and log(g)) from which we model the spectral energy distribution (SED) from these stars which have pure hydrogen atmospheres. By comparing against panchromatic broadband HST photometry, and allowing for an achromatic zero-point adjustment and mild scaling of the interstellar reddening, we find that model prediction and observation agree to a few milli-mag. By combining the zero-point and reddening adjustments with the modeled SED, for each star we obtain the incident SED above the terrestrial atmosphere, thus establishing these objects as spectrophotometric standards. We are pursuing 23 objects between 16 and 19 mag spread over the sky uniformly around the equator and northern mid-latitudes, with plans to extend this to southern latitudes. This precision photometric heritage from HST will benefit essentially all existing and upcoming survey projects, and in prticular, directly addresses one of the current barriers to understanding the nature of dark energy.

    13. Deepest Infrared View of the Universe

      NASA Astrophysics Data System (ADS)

      2002-12-01

      VLT Images Progenitors of Today's Large Galaxies Summary An international team of astronomers [2] has made the deepest-ever near-infrared Ks-band image of the sky, using the ISAAC multi-mode instrument on the 8.2-m VLT ANTU telescope. For this, the VLT was pointed for more than 100 hours under optimal observing conditions at the Hubble Deep Field South (HDF-S) and obtained images in three near-infrared filters. The resulting images reveal extremely distant galaxies, which appear at infrared wavelengths, but are barely detected in the deepest optical images acquired with the Hubble Space Telescope (HST). Astronomer Marijn Franx from the University of Leiden and leader of the team concludes: "These results demonstrate that very deep observations in the near-infrared are essential to obtain a proper census of the earliest phases of the universe. The new VLT images have opened a new research domain which has not been observationally accessible before". The HDF-S is a tiny field on the sky in the southern constellation Tucana (The Toucan) - only about 1% of the area of the full moon. The NASA/ESA Hubble Space Telescope (HST) observed it with a total exposure time of about 1 week, yielding the deepest optical images ever taken of the sky, similar to those made earlier on the Hubble Deep Field North (HDF-N). The VLT infrared images of the same field were obtained in the course of a major research project, the Faint InfraRed Extragalactic Survey (FIRES). They were made at wavelengths up to 2.3 µm where the HST is not competitive. Ivo Labbé, another team member from the University of Leiden, is certain: "Without the unique capabilities of the VLT and ISAAC we would never have been able to observe these very remote galaxies. In fact, the image in the Ks-band is the deepest which has ever been made at that wavelength". The optical light emitted by the distant galaxies has been redshifted to the near-infrared spectral region [3]. Indeed, some of the galaxies found in the new

    14. PSST discovery of a faint transient in NGC 6012

      NASA Astrophysics Data System (ADS)

      Smith, K. W.; Wright, D.; Smartt, S. J.; Young, D. R.; Huber, M.; Chambers, K. C.; Flewelling, H.; Willman, M.; Primak, N.; Schultz, A.; Gibson, B.; Magnier, E.; Waters, C.; Tonry, J.; Wainscoat, R. J.; Foley, R. J.; Jha, S. W.; Rest, A.; Scolnic, D.

      2016-06-01

      A transient object has been discovered near NGC 6012 as part of the Pan-STARRS Survey for Transients (PSST). Information on all objects discovered by the Pan-STARRS Survey for Transients is available at http://star.pst.qub.ac.uk/ps1threepi/ (see Huber et al. ATel #7153).

    15. Adaptive optics for high-contrast imaging of faint substellar companions

      NASA Astrophysics Data System (ADS)

      Morzinski, Katie M.

      Direct imaging of faint objects around bright stars is challenging because the primary star's diffracted light can overwhelm low-mass companions. Nevertheless, advances in adaptive optics (AO) and high-contrast imaging have revealed the first pictures of extrasolar planets. In this dissertation I employ today's high-contrast AO techniques to image brown dwarfs around stars in the nearby Hyades cluster. Furthermore, I prepare for the next generation of high-contrast AO instrumentation, by qualifying MEMS deformable mirrors for wavefront control in the Gemini Planet Imager. In Part I, I present discovery of 3 new brown dwarfs and 36 low-mass stellar companions to 85 stars in the Hyades, imaged with AO at Keck and Lick Observatories. The "locally-optimized combination of images" (LOCI) image-diversity technique filters out the primary star to reveal faint companions. This survey is complete to the hydrogen-burning limit at separations beyond 20 AU. In the complete sample, multiplicity increases as primary star mass decreases. Additionally, the brown dwarfs are at wide >150 AU separations. Finding this preference for low binding-energy systems is an unexpected result, as the Hyades is 625 Myr old and dynamically relaxed. Future work will continue to explore this trend to understand the dynamical and star formation history of the Hyades. The brown dwarfs are near interesting transition regimes for low-mass objects; therefore, characterizing their atmospheres with spectrophotometry will serve as an important benchmark for our understanding of these cool objects. In Part II, I demonstrate micro-electro-mechanical systems (MEMS) deformable mirrors for high-order wavefront control in the Gemini Planet Imager (GPI). MEMS micromirrors have thousands of degrees of freedom and represent a significant cost efficiency over conventional glass deformable mirrors, making them ideal for high-contrast AO. In Chapter 7, I present experimental evidence that MEMS actuators function well

    16. A single prolific r-process event preserved in an ultra-faint dwarf galaxy

      NASA Astrophysics Data System (ADS)

      Ji, Alexander; Frebel, Anna; Chiti, Anirudh; Simon, Joshua

      2016-03-01

      The heaviest elements in the periodic table are synthesized through the r-process, but the astrophysical site for r-process nucleosynthesis is still unknown. Ultra-faint dwarf galaxies contain a simple fossil record of early chemical enrichment that may determine this site. Previous measurements found very low levels of neutron-capture elements in ultra-faint dwarfs, preferring supernovae as the r-process site. I present high-resolution chemical abundances of nine stars in the recently discovered ultra-faint dwarf Reticulum II, which display extremely enhanced r-process abundances 2-3 orders of magnitude higher than the other ultra-faint dwarfs. Stars with such extreme r-process enhancements are only rarely found in the Milky Way halo. The r-process abundances imply that the neutron-capture material in Reticulum II was synthesized in a single prolific event that is incompatible with r-process yields from ordinary core-collapse supernovae. Reticulum II provides an opportunity to discriminate whether the source of this pure r-process signature is a neutron star merger or magnetorotationally driven supernova. The single event is also a uniquely stringent constraint on the metal mixing and star formation history of this ultra-faint dwarf galaxy.

    17. The universe at faint magnitudes. I - Models for the galaxy and the predicted star counts

      NASA Astrophysics Data System (ADS)

      Bahcall, J. N.; Soneira, R. M.

      1980-09-01

      A detailed model is constructed for the disk and spheroid components of the Galaxy from which the distribution of visible stars and mass in the Galaxy is calculated. The application of star counts to the determination of galactic structure parameters is demonstrated. The possibility of detecting a halo component with the aid of star counts is also investigated quantitatively. The stellar luminosity functions and scale heights are determined from observations in the solar neighborhood. The global distribution of matter is assumed, based on studies of other galaxies, to be an exponential disk plus a de Vaucouleurs spheroid. The spheroid luminosity function is found to have the same shape as the disk luminosity function over the range of absolute magnitudes (+4 to + 12) that contributes significantly to the star counts for mV ≤ 30. The density of spheroid stars in the solar neighborhood is 1/800 of the value for the disk. The star counts calculated using the density variation of a de Vaucouleurs spheroid are consistent with the available data; the counts predicted with the aid of a Hubble law are inconsistent with observations at more than the two-sigma level of significance. The variations of the calculated star densities with apparent magnitude, latitude, and longitude agree well with the available star count data for the observationally well studied range of 4 ≲ mV ≲ 22. The calculated (B - V) color distributions are also in good agreement with existing data. The color data also indicate that QSOs comprise only a few percent of the total number of stellar objects to mV = 22 (mB = 22.5). The spheroid component is found to be approximately spherical. The scale lengths of the Galaxy model and computed total luminosity and M/L ratios for the disk and spheroid are in agreement with observations of other Sbc galaxies. Illustrative Fig. and a table of interesting characteristics (such as the mass and luminosity contained within various radii and the escape velocity

    18. Cosmic Infrared Background Fluctuations in Deep Spitzer Infrared Array Camera Images: Data Processing and Analysis

      NASA Technical Reports Server (NTRS)

      Arendt, Richard; Kashlinsky, A.; Moseley, S.; Mather, J.

      2010-01-01

      This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer Infrared Array Camera observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations that would otherwise corrupt the results. The procedures and results for masking bright sources and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large-scale ([greater, similar]30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power-law components. We discuss the relationship between fluctuations measured at different wavelengths and depths, and the relations between constraints on the mean intensity of the CIB and its fluctuation spectrum. Consistent with growing evidence that the [approx]1-5 [mu]m mean intensity of the CIB may not be as far above the integrated emission of resolved galaxies as has been reported in some analyses of DIRBE and IRTS observations, our measurements of spatial fluctuations of the CIB intensity indicate the mean emission from the objects producing the fluctuations is quite low ([greater, similar]1 nW m-2 sr-1 at 3-5 [mu]m), and thus consistent with current [gamma]-ray absorption constraints. The source of the fluctuations may be high-z Population III objects, or a more local component of very low luminosity objects with clustering properties that differ from the resolved galaxies. Finally, we discuss the prospects of the upcoming space-based surveys to directly measure the epochs

    19. A search for faint companions of the nearest stars with CanariCam and VHS .

      NASA Astrophysics Data System (ADS)

      Gauza, B.; Béjar, V. J. S.; Rebolo, R.; érez-Garrido, A. P.; Lodieu, N.; Álvarez, C.; UCD Group of the VHS; substellar Group of the CCST

      After two decades of discoveries, the census of substellar objects in the solar neighborhood remains incomplete. Current imaging surveys carried out in the near and mid-infrared are expected to unveil numerous ultracool dwarfs and expand the population to previously undetectable temperature ranges. Here we present a review of our searches for substellar companions around stars in the solar vicinity (d<10 pc). The searches are based on the southern near-infrared VISTA Hemisphere Survey (VHS) combined with WISE and 2MASS catalogues and on a deep mid-IR imaging program carried out with CanariCam at the 10.4m GTC, in the Northern sky. We achieve sensitivity and resolving power that enables us to detect early Y dwarfs (T_eff˜300-500 K) at separations larger than 10 AU.

    20. Astronomical polarization studies at radio and infrared wavelengths. Part 2: Far infrared polarization of dust clouds

      NASA Technical Reports Server (NTRS)

      Dennison, B. K.

      1976-01-01

      Far infrared polarization of dust clouds is examined. The recently observed 10 micron polarization of the Orion Nebula and the Galactic Center suggests that far infrared polarization may be found in these objects. Estimates are made of the degree of far infrared polarization that may exist in the Orion Nebula. An attempt to observe far infrared polarization from the Orion Nebula was carried out.

    1. Infrared Astronomy

      NASA Astrophysics Data System (ADS)

      Mampaso, A.; Prieto, M.; Sánchez, F.

      2004-01-01

      What do we understand of the birth and death of stars? What is the nature of the tiny dust grains that permeate our Galaxy and other galaxies? And how likely is the existence of brown dwarfs, extrasolar planets or other sub-stellar mass objects? These are just a few of the questions that can now be addressed in a new era of infrared observations. IR astronomy has been revolutionised over the past few years by the widespread availability of large, very sensitive IR arrays and the success of IR satellites (IRAS in particular). Several IR space missions due for launch over the next few years promise an exciting future too. For these reasons, the IV Canary Islands Winter School of Astrophysics was dedicated to this burgeoning field. Its primary goal was to introduce graduate students and researchers from other areas to the important new observations and physical ideas that are emerging in this wide-ranging field of research. Lectures from nine leading researchers, renowned for their teaching abilities, are gathered in this volume. These nine chapters provide an excellent introduction as well as a thorough and up-to-date review of developments - essential reading for graduate students entering IR astronomy, and professionals from other areas who realise the importance that IR astronomy may have on their research.

    2. The Subaru High-z Quasar Survey: Discovery of Faint z ~ 6 Quasars

      NASA Astrophysics Data System (ADS)

      Kashikawa, Nobunari; Ishizaki, Yoshifumi; Willott, Chris J.; Onoue, Masafusa; Im, Myungshin; Furusawa, Hisanori; Toshikawa, Jun; Ishikawa, Shogo; Niino, Yuu; Shimasaku, Kazuhiro; Ouchi, Masami; Hibon, Pascale

      2015-01-01

      We present the discovery of one or two extremely faint z ~ 6 quasars in 6.5 deg2 utilizing a unique capability of the wide-field imaging of the Subaru/Suprime-Cam. The quasar selection was made in (i'-zB ) and (zB -zR ) colors, where zB and zR are bandpasses with central wavelengths of 8842 Å and 9841 Å, respectively. The color selection can effectively isolate quasars at z ~ 6 from M/L/T dwarfs without the J-band photometry down to zR < 24.0, which is 3.5 mag deeper than the Sloan Digital Sky Survey (SDSS). We have selected 17 promising quasar candidates. The follow-up spectroscopy for seven targets identified one apparent quasar at z = 6.156 with M 1450 = -23.10. We also identified one possible quasar at z = 6.041 with a faint continuum of M 1450 = -22.58 and a narrow Lyα emission with HWHM =427 km s-1, which cannot be distinguished from Lyman α emitters. We derive the quasar luminosity function at z ~ 6 by combining our faint quasar sample with the bright quasar samples by SDSS and CFHQS. Including our data points invokes a higher number density in the faintest bin of the quasar luminosity function than the previous estimate employed. This suggests a steeper faint-end slope than lower z, though it is yet uncertain based on a small number of spectroscopically identified faint quasars, and several quasar candidates still remain to be diagnosed. The steepening of the quasar luminosity function at the faint end does increase the expected emission rate of the ionizing photon; however, it only changes by a factor of approximately two to six. This was found to still be insufficient for the required photon budget of reionization at z ~ 6.

    3. FIRST-2MASS RED QUASARS: TRANSITIONAL OBJECTS EMERGING FROM THE DUST

      SciTech Connect

      Glikman, Eilat; Urrutia, Tanya; Lacy, Mark; Djorgovski, S. George; Mahabal, Ashish; Myers, Adam D.; Ross, Nicholas P.; Petitjean, Patrick; Ge, Jian; Schneider, Donald P.; York, Donald G.

      2012-09-20

      We present a sample of 120 dust-reddened quasars identified by matching radio sources detected at 1.4 GHz in the Faint Images of the Radio Sky at Twenty Centimeters survey with the near-infrared Two Micron All Sky Survey catalog and color-selecting red sources. Optical and/or near-infrared spectroscopy provide broad wavelength sampling of their spectral energy distributions that we use to determine their reddening, characterized by E(B - V). We demonstrate that the reddening in these quasars is best described by Small-Magellanic-Cloud-like dust. This sample spans a wide range in redshift and reddening (0.1 {approx}< z {approx}< 3, 0.1 {approx}< E(B - V) {approx}< 1.5), which we use to investigate the possible correlation of luminosity with reddening. At every redshift, dust-reddened quasars are intrinsically the most luminous quasars. We interpret this result in the context of merger-driven quasar/galaxy co-evolution where these reddened quasars are revealing an emergent phase during which the heavily obscured quasar is shedding its cocoon of dust prior to becoming a 'normal' blue quasar. When correcting for extinction, we find that, depending on how the parent population is defined, these red quasars make up {approx}< 15%-20% of the luminous quasar population. We estimate, based on the fraction of objects in this phase, that its duration is 15%-20% as long as the unobscured, blue quasar phase.

    4. FAINT POPULATION III SUPERNOVAE AS THE ORIGIN OF THE MOST IRON-POOR STARS

      SciTech Connect

      Ishigaki, Miho N.; Tominaga, Nozomu; Kobayashi, Chiaki; Nomoto, Ken'ichi

      2014-09-10

      The most iron-poor stars in the Milky Way provide important observational clues to the astrophysical objects that enriched the primordial gas with heavy elements. Among them, the recently discovered iron-deficient star SMSS J031300.36–670839.3 shows a remarkable chemical composition with a non-detection of iron ([Fe/H] <–7.1) and large enhancement of carbon and magnesium relative to calcium. We investigate supernova yields of metal-free (Population III) stars to interpret the abundance pattern observed in this star. We report that the high [C/Ca] and [C/Mg] ratios and upper limits of other elemental abundances are well reproduced with the yields of core-collapse supernovae (which have normal kinetic energies of explosion E of E {sub 51} = E/10{sup 51} erg =1) and hypernovae (E {sub 51} ≥ 10) of Population III 25 M {sub ☉} or 40 M {sub ☉} stars. The best-fit models assume that the explosions undergo extensive matter mixing and fallback, leaving behind a black hole remnant. In these models, Ca is produced by static/explosive O burning and incomplete Si burning in the Population III supernova/hypernova, in contrast to the suggestion that Ca is originated from the hot-CNO cycle during pre-supernova evolution. Chemical abundances of four carbon-rich iron-poor stars with [Fe/H] <–4.5, including SMSS J031300.36–670839.3, are consistently explained by faint supernova models with ejected masses of {sup 56}Ni less than 10{sup –3} M {sub ☉}.

    5. Detection of a Faint Fast-moving Near-Earth Asteroid Using the Synthetic Tracking Technique

      NASA Astrophysics Data System (ADS)

      Zhai, Chengxing; Shao, Michael; Nemati, Bijan; Werne, Thomas; Zhou, Hanying; Turyshev, Slava G.; Sandhu, Jagmit; Hallinan, Gregg; Harding, Leon K.

      2014-09-01

      We report a detection of a faint near-Earth asteroid (NEA) using our synthetic tracking technique and the CHIMERA instrument on the Palomar 200 inch telescope. With an apparent magnitude of 23 (H = 29, assuming detection at 20 lunar distances), the asteroid was moving at 6.°32 day-1 and was detected at a signal-to-noise ratio (S/N) of 15 using 30 s of data taken at a 16.7 Hz frame rate. The detection was confirmed by a second observation 77 minutes later at the same S/N. Because of its high proper motion, the NEA moved 7 arcsec over the 30 s of observation. Synthetic tracking avoided image degradation due to trailing loss that affects conventional techniques relying on 30 s exposures; the trailing loss would have degraded the surface brightness of the NEA image on the CCD down to an approximate magnitude of 25 making the object undetectable. This detection was a result of our 12 hr blind search conducted on the Palomar 200 inch telescope over two nights, scanning twice over six (5.°3 × 0.°046) fields. Detecting only one asteroid is consistent with Harris's estimates for the distribution of the asteroid population, which was used to predict a detection of 1.2 NEAs in the H-magnitude range 28-31 for the two nights. The experimental design, data analysis methods, and algorithms are presented. We also demonstrate milliarcsecond-level astrometry using observations of two known bright asteroids on the same system with synthetic tracking. We conclude by discussing strategies for scheduling observations to detect and characterize small and fast-moving NEAs using the new technique.

    6. Detection of a faint fast-moving near-Earth asteroid using the synthetic tracking technique

      SciTech Connect

      Zhai, Chengxing; Shao, Michael; Nemati, Bijan; Werne, Thomas; Zhou, Hanying; Turyshev, Slava G.; Sandhu, Jagmit; Hallinan, Gregg; Harding, Leon K.

      2014-09-01

      We report a detection of a faint near-Earth asteroid (NEA) using our synthetic tracking technique and the CHIMERA instrument on the Palomar 200 inch telescope. With an apparent magnitude of 23 (H = 29, assuming detection at 20 lunar distances), the asteroid was moving at 6.°32 day{sup –1} and was detected at a signal-to-noise ratio (S/N) of 15 using 30 s of data taken at a 16.7 Hz frame rate. The detection was confirmed by a second observation 77 minutes later at the same S/N. Because of its high proper motion, the NEA moved 7 arcsec over the 30 s of observation. Synthetic tracking avoided image degradation due to trailing loss that affects conventional techniques relying on 30 s exposures; the trailing loss would have degraded the surface brightness of the NEA image on the CCD down to an approximate magnitude of 25 making the object undetectable. This detection was a result of our 12 hr blind search conducted on the Palomar 200 inch telescope over two nights, scanning twice over six (5.°3 × 0.°046) fields. Detecting only one asteroid is consistent with Harris's estimates for the distribution of the asteroid population, which was used to predict a detection of 1.2 NEAs in the H-magnitude range 28-31 for the two nights. The experimental design, data analysis methods, and algorithms are presented. We also demonstrate milliarcsecond-level astrometry using observations of two known bright asteroids on the same system with synthetic tracking. We conclude by discussing strategies for scheduling observations to detect and characterize small and fast-moving NEAs using the new technique.

    7. Exploring the spectral properties of faint hard X-ray sources with XMM-Newton

      NASA Astrophysics Data System (ADS)

      Piconcelli, E.; Cappi, M.; Bassani, L.; Fiore, F.; Di Cocco, G.; Stephen, J. B.

      2002-11-01

      We present a spectroscopic study of 41 hard X-ray sources detected serendipitously with high significance (>5sigma in the 2-10 keV band) in seven EPIC performance/verification phase observations. The large collecting area of EPIC allows us to explore the spectral properties of these faint hard X-ray sources with 2 < F2-10 < 80 x 10-14 erg cm-2 s-1 even though the length of the exposures are modest ( ~ 20 ks). Optical identifications are available for 21 sources of our sample. Using a simple power law plus Galactic absorption model we find an average value of the photon index Gamma ~ 1.6-1.7, broadly consistent with recent measurements made at similar fluxes with ASCA and with Chandra stacked spectral analyses. We find that 31 out of 41 sources are well fitted by this simple model and only eight sources require absorption in excess of the Galactic value. Interestingly enough, one third of these absorbed sources are broad line objects, though with moderate column densities. Two sources in the sample are X-ray bright optically quiet galaxies and show flat X-ray spectra. Comparing our observational results with those expected from standard synthesis models of the cosmic X-ray background (CXB) we find a fraction of unabsorbed to absorbed sources larger than predicted by theoretical models at our completeness limit of F2-10 ~ 5 x 10-14 erg cm-2 s-1. The results presented here illustrate well how wide-angle surveys performed with EPIC on board XMM-Newton allow population studies of interesting and unusual sources to be made as well as enabling constraints to be placed on some input parameters for synthesis models of the CXB.

    8. HAWAII QUASAR AND T DWARF SURVEY. I. METHOD AND DISCOVERY OF FAINT FIELD ULTRACOOL DWARFS ,

      SciTech Connect

      Kakazu, Yuko; Capak, Peter L.; Hu, Esther M.; Liu, Michael C.; Wainscoat, Richard J.; Wang Weihao

      2010-11-01

      The Hawaii Quasar and T dwarf survey (HQT Survey) is a wide-field, red optical survey carried out with the Suprime-Cam mosaic CCD camera on the 8.2 m Subaru telescope. The HQT survey is designed to search for low-luminosity (M{sub AB1450} < -23) quasars at high redshift (z>5.7) as well as T dwarfs, both of which are selected by their very red I - z' colors. We use an optical narrowband filter NB816 to break a well-known I - z' color degeneracy between high-z quasars and foreground M and L dwarfs, which are more numerous than quasars. This paper is the first in a series of papers from the HQT survey and we report on the discovery of six faint (19 {<=} J {<=} 20) ultracool dwarfs found over a {approx}9.3 deg{sup 2} area with a limiting magnitude of z'{sub AB} {<=} 23.3. These dwarfs were confirmed by near-IR imaging and/or spectroscopy conducted at various facilities on Mauna Kea. With estimated distances of 60-170 pc, these are among the most distant spectroscopically confirmed field brown dwarfs to date. Limits on the proper motions of these ultracool dwarfs suggest that they are old members of the Galactic disk, though future follow-up observations are necessary to minimize errors. Our finding rate of ultracool dwarfs is within model predictions of Liu et al. However, the large brightening amplitude ({approx}1 mag) previously reported for the L/T transition objects appears to overpredict the numbers. We also examine how the survey field latitude affects the survey sensitivity to the vertical scale height of ultracool dwarfs.

    9. Identification of 1.4 Million Active Galactic Nuclei in the Mid-Infrared using WISE Data

      NASA Astrophysics Data System (ADS)

      Secrest, N. J.; Dudik, R. P.; Dorland, B. N.; Zacharias, N.; Makarov, V.; Fey, A.; Frouard, J.; Finch, C.

      2015-11-01

      We present an all-sky sample of ≈1.4 million active galactic nuclei (AGNs) meeting a two-color infrared photometric selection criteria for AGNs as applied to sources from the Wide-field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution and optical properties of our sample and find that the results are consistent with expectations for AGNs. These sources have a mean density of ≈38 AGNs per square degree on the sky, and their apparent magnitude distribution peaks at g ≈ 20, extending to objects as faint as g ≈ 26. We test the AGN selection criteria against a large sample of optically identified stars and determine the “leakage” (that is, the probability that a star detected in an optical survey will be misidentified as a quasi-stellar object (QSO) in our sample) rate to be ≤4.0 × 10-5. We conclude that our sample contains almost no optically identified stars (≤0.041%), making this sample highly promising for future celestial reference frame work as it significantly increases the number of all-sky, compact extragalactic objects. We further compare our sample to catalogs of known AGNs/QSOs and find a completeness value of ≳84% (that is, the probability of correctly identifying a known AGN/QSO is at least 84%) for AGNs brighter than a limiting magnitude of R ≲ 19. Our sample includes approximately 1.1 million previously uncataloged AGNs.

    10. Big Fish, Little Fish: Two New Ultra-faint Satellites of the Milky Way

      NASA Astrophysics Data System (ADS)

      Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Just, D.; Koposov, S.; Mateo, M.; Olszewski, E.; Watkins, L.; Wyrzykowski, L.

      2010-03-01

      We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of ~180 kpc, some 15° away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of ~60 pc, while Segue 3 is 20 times smaller at only 3 pc.

    11. Sweating the small stuff: simulating dwarf galaxies, ultra-faint dwarf galaxies, and their own tiny satellites

      NASA Astrophysics Data System (ADS)

      Wheeler, Coral Rose

      2016-06-01

      The high dark matter content and the shallow potential wells of low mass galaxies (10^3 Msun < Mstar < 10^9.5 Msun) make them excellent testbeds for differing theories of galaxy formation. Additionally, the recent up-tick in the number and detail of Local Group dwarf galaxy observations provides a rich dataset for comparison to simulations that attempt to answer important questions in near field cosmology: why are there so few observed dwarfs compared to the number predicted by simulations? What shuts down star formation in ultra-faint galaxies? Why do dwarfs have inverted age gradients and what does it take to convert a dwarf irregular (dIrrs) into a dwarf spheroidal (dSph) galaxy?We to attempt to answer these questions by running ultra-high resolution cosmological FIRE simulations of isolated dwarf galaxies. We predict that many ultra-faint dwarfs should exist as satellites of more massive isolated Local Group dwarfs. The ultra-faints (Mstar < 10^4 Msun) formed in these simulations have uniformly ancient stellar populations (> 10 Gyr), having had their star formation shut down by reionization. Additionally, we show that the kinematics and ellipticities of isolated simulated dwarf centrals are consistent with observed dSphs satellites without the need for harassment from a massive host. We further show that most (but not all) observed *isolated* dIrrs in the Local Volume also have dispersion-supported stellar populations, contradicting the previous view that these objects are rotating. Finally, we investigate the stellar age gradients in dwarfs — showing that early mergers and strong feedback can create an inverted gradient, with the older stars occupying larger galactocentric radii.These results offer an interesting direction in testing models that attempt to solve dark matter problems via explosive feedback episodes. Can the same models that create large cores in simulated dwarfs preserve the mild stellar rotation that is seen in a minority of isolated d

    12. Faint Luminescent Ring over Saturn’s Polar Hexagon

      NASA Astrophysics Data System (ADS)

      Adriani, Alberto; Moriconi, Maria Luisa; D’Aversa, Emiliano; Oliva, Fabrizio; Filacchione, Gianrico

      2015-07-01

      Springtime insolation is presently advancing across Saturn's north polar region. Early solar radiation scattered through the gaseous giant's atmosphere gives a unique opportunity to sound the atmospheric structure at its upper troposphere/lower stratosphere at high latitudes. Here, we report the detection of a tenuous bright structure in Saturn's northern polar cap corresponding to the hexagon equatorward boundary, observed by Cassini Visual and Infrared Mapping Spectrometer on 2013 June. The structure is spectrally characterized by an anomalously enhanced intensity in the 3610–3730 nm wavelength range and near 2500 nm, pertaining to relatively low opacity windows between strong methane absorption bands. Our first results suggest that a strong forward scattering by tropospheric clouds, higher in respect to the surrounding cloud deck, can be responsible for the enhanced intensity of the feature. This can be consistent with the atmospheric dynamics associated with the jet stream embedded in the polar hexagon. Further investigations at higher spectral resolution are needed to better assess the vertical distribution and microphysics of the clouds in this interesting region.

    13. Deconvolution of post-adaptive optics images of faint circumstellar environments by means of the inexact Bregman procedure

      NASA Astrophysics Data System (ADS)

      Benfenati, A.; La Camera, A.; Carbillet, M.

      2016-02-01

      Aims: High-dynamic range images of astrophysical objects present some difficulties in their restoration because of the presence of very bright point-wise sources surrounded by faint and smooth structures. We propose a method that enables the restoration of this kind of images by taking these kinds of sources into account and, at the same time, improving the contrast enhancement in the final image. Moreover, the proposed approach can help to detect the position of the bright sources. Methods: The classical variational scheme in the presence of Poisson noise aims to find the minimum of a functional compound of the generalized Kullback-Leibler function and a regularization functional: the latter function is employed to preserve some characteristic in the restored image. The inexact Bregman procedure substitutes the regularization function with its inexact Bregman distance. This proposed scheme allows us to take under control the level of inexactness arising in the computed solution and permits us to employ an overestimation of the regularization parameter (which balances the trade-off between the Kullback-Leibler and the Bregman distance). This aspect is fundamental, since the estimation of this kind of parameter is very difficult in the presence of Poisson noise. Results: The inexact Bregman procedure is tested on a bright unresolved binary star with a faint circumstellar environment. When the sources' position is exactly known, this scheme provides us with very satisfactory results. In case of inexact knowledge of the sources' position, it can in addition give some useful information on the true positions. Finally, the inexact Bregman scheme can be also used when information about the binary star's position concerns a connected region instead of isolated pixels.

    14. Preliminary analysis on faint luminous lightning events recorded by multiple high speed cameras

      NASA Astrophysics Data System (ADS)

      Alves, J.; Saraiva, A. V.; Pinto, O.; Campos, L. Z.; Antunes, L.; Luz, E. S.; Medeiros, C.; Buzato, T. S.

      2013-12-01

      The objective of this work is the study of some faint luminous events produced by lightning flashes that were recorded simultaneously by multiple high-speed cameras during the previous RAMMER (Automated Multi-camera Network for Monitoring and Study of Lightning) campaigns. The RAMMER network is composed by three fixed cameras and one mobile color camera separated by, in average, distances of 13 kilometers. They were located in the Paraiba Valley (in the cities of São José dos Campos and Caçapava), SP, Brazil, arranged in a quadrilateral shape, centered in São José dos Campos region. This configuration allowed RAMMER to see a thunderstorm from different angles, registering the same lightning flashes simultaneously by multiple cameras. Each RAMMER sensor is composed by a triggering system and a Phantom high-speed camera version 9.1, which is set to operate at a frame rate of 2,500 frames per second with a lens Nikkor (model AF-S DX 18-55 mm 1:3.5 - 5.6 G in the stationary sensors, and a lens model AF-S ED 24 mm - 1:1.4 in the mobile sensor). All videos were GPS (Global Positioning System) time stamped. For this work we used a data set collected in four RAMMER manual operation days in the campaign of 2012 and 2013. On Feb. 18th the data set is composed by 15 flashes recorded by two cameras and 4 flashes recorded by three cameras. On Feb. 19th a total of 5 flashes was registered by two cameras and 1 flash registered by three cameras. On Feb. 22th we obtained 4 flashes registered by two cameras. Finally, in March 6th two cameras recorded 2 flashes. The analysis in this study proposes an evaluation methodology for faint luminous lightning events, such as continuing current. Problems in the temporal measurement of the continuing current can generate some imprecisions during the optical analysis, therefore this work aim to evaluate the effects of distance in this parameter with this preliminary data set. In the cases that include the color camera we analyzed the RGB

    15. The First Hyper-Luminous Infrared Galaxy Discovered by WISE

      NASA Technical Reports Server (NTRS)

      Eisenhardt, Peter R.; Wu, Jingwen; Tsai, Chao-Wei; Assef, Roberto; Benford, Dominic; Blain, Andrew; Bridge, Carrie; Condon, J. J.; Cushing, Michael C.; Cutri, Roc; Evans, Neal J., III; Gelino, Chris; Griffith, Roger L.; Grillmair, Carl J.; Jarrett, Tom; Lonsdale, Carol J.; Masci, Frank J.; Mason, Brian S.; Petty, Sara; Sayers, Jack; Stanford, S. Adam; Stern, Daniel; Wright, Edward L.; Yan, Lin

      2012-01-01

      We report the discovery by the Wide-field Infrared Survey Explorer of the z = 2.452 source WISEJ181417.29+341224.9, the first hyperluminous source found in the WISE survey. WISE 1814+3412 is also the prototype for an all-sky sample of approximately 1000 extremely luminous "W1W2-dropouts" (sources faint or undetected by WISE at 3.4 and 4.6 micrometers and well detected at 12 or 22 micrometers). The WISE data and a 350 micrometers detection give a minimum bolometric luminosity of 3.7 x 10(exp 13) solar luminosity, with approximately 10(exp 14) solar luminosity plausible. Followup images reveal four nearby sources: a QSO and two Lyman Break Galaxies (LBGs) at z = 2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission. Gravitational lensing is unlikely given the source locations and their different spectra and colors. The dominant LBG spectrum indicates a star formation rate approximately 300 solar mass yr(exp -1), accounting for less than or equal to 10 percent of the bolometric luminosity. Strong 22 micrometer emission relative to 350 micrometer implies that warm dust contributes significantly to the luminosity, while cooler dust normally associated with starbursts is constrained by an upper limit at 1.1 mm. Radio emission is approximately 10? above the far-infrared/radio correlation, indicating an active galactic nucleus is present. An obscured AGN combined with starburst and evolved stellar components can account for the observations. If the black hole mass follows the local MBH-bulge mass relation, the implied Eddington ratio is approximately greater than 4. WISE 1814+3412 may be a heavily obscured object where the peak AGN activity occurred prior to the peak era of star formation.

    16. Deep galaxy count predictions in the radio, infrared, and X-ray spectral bands

      NASA Technical Reports Server (NTRS)

      Treyer, Marie-Agnes; Silk, Joseph

      1993-01-01

      The existence of a dominant population of strongly evolving starburst sources at moderate redshift is a plausible explanation for the excess number of faint blue galaxies detected in deep sky surveys. Multiwavelength observations at faint magnitudes would allow the existence of such a population to be confirmed. We use observed luminosity correlations and physical properties of known starburst galaxies to predict their contribution to the deep radio, infrared, and X-ray counts, as well as to the diffuse extragalactic background radiation in these various spectral bands.

    17. VizieR Online Data Catalog: YSOVAR: infrared photometry in Lynds 1688 (Gunther+, 2014)

      NASA Astrophysics Data System (ADS)

      Gunther, H. M.; Cody, A. M.; Covey, K. R.; Hillenbrand, L. A.; Plavchan, P.; Poppenhaeger, K.; Rebull, L. M.; Stauffer, J. R.; Wolk, S. J.; Allen, L.; Bayo, A.; Gutermuth, R. A.; Hora, J. L.; Meng, H. Y. A.; Morales-Calderon, M.; Parks, J. R.; Song, I.

      2014-11-01

      We present a Spitzer/IRAC monitoring campaign of the star-forming region L1688 in the mid-infrared. Lynds 1688 (L1688) is a subcloud of the {rho} Ophiuchus star-forming region. Three fields in L1688 were observed with Spitzer in four observing windows from 2010 April 12 to 2010 May 16 (visibility window 1), 2010 September 22 to 2010 October 27 (visibility window 2), 2011 April 20 to 2011 May 23 (visibility window 3), and 2011 October 1 to 2011 November 6 (visibility window 4). These windows are consecutive visibility periods dictated by the Spitzer orbit (Werner et al., 2004ApJS..154....1W). Table1 lists the time of each observation. They can be found under Program Identification number (PID) 61024 in the Spitzer Heritage Archive (http://sha.ipac.caltech.edu/applications/Spitzer/SHA). L1688 was observed by Chandra on 2000 April 13 for 100ks exposure time in the FAINT mode with the ACIS instrument (ObsID 635 in the Chandra Data Archive, http://cda.harvard.edu/chaser/). We found auxiliary data from the literature. L1688 was observed with Spitzer in the cryogenic mission phase with all four IRAC channels and the 24μm channel of the Multiband Imaging Photometer for Spitzer (MIPS). We augment our own Spitzer data reduction with values from the catalog published by the c2d project (c2d = "From Cores to Disks"; Evans et al. 2003, cat. II/332). Near-infrared data are taken from 2MASS (cat. II/246). Additionally, we take detections from the UKIRT Infrared Deep Sky Survey (UKIDSS; cat. II/319) Galactic cluster survey, data release 9. UKIDSS uses the United Kingdom Infrared Telescope (UKIRT) Wide Field Camera. The YSOVAR data is also cross-matched with data from the SIMBAD (http://simbad.u-strasbg.fr/simbad/) service to provide an identification with known objects from the literature. (4 data files).

    18. VizieR Online Data Catalog: 72 faint CV candidates in CRTS (Breedt+, 2014)

      NASA Astrophysics Data System (ADS)

      Breedt, E.; Gansicke, B. T.; Drake, A. J.; Rodriguez-Gil, P.; Parsons, S. G.; Marsh, T. R.; Szkody, P.; Schreiber, M. R.; Djorgovski, S. G.

      2016-04-01

      We obtained identification spectra of a total of 72 faint CV candidates identified by the CRTS, using the Gran Telescopio Canarias (GTC; La Palma, Spain) and the Gemini telescopes (North: Mauna Kea, Hawaii and South: Cerro Pachon, Chile). The observations were carried out in service mode during 2010, 2011 and 2013. (5 data files).

    19. View of southeast side, faint "141" sign, Cranes P76 and ...

      Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

      View of southeast side, faint "141" sign, Cranes P-76 and P-71 are behind, view facing northwest - U.S. Naval Base, Pearl Harbor, Dry Dock No. 1, Latrine, Sixth Street, adjacent to Dry Dock No. 1, Pearl City, Honolulu County, HI

    20. Faint laser pulses versus a single-photon source in free space quantum cryptography

      NASA Astrophysics Data System (ADS)

      Molotkov, S. N.; Potapova, T. A.

      2016-03-01

      In this letter we present estimates for the distance of secret key transmission through free space for three different protocols of quantum key distribution: for BB84 and phase time-coding protocols in the case of a strictly single-photon source, and for the relativistic quantum key distribution protocol in the case of faint laser pulses.

    1. Optical and near-IR observations of the faint and fast 2008ha-like supernova 2010ae

      NASA Astrophysics Data System (ADS)

      Stritzinger, M. D.; Hsiao, E.; Valenti, S.; Taddia, F.; Rivera-Thorsen, T. J.; Leloudas, G.; Maeda, K.; Pastorello, A.; Phillips, M. M.; Pignata, G.; Baron, E.; Burns, C. R.; Contreras, C.; Folatelli, G.; Hamuy, M.; Höflich, P.; Morrell, N.; Prieto, J. L.; Benetti, S.; Campillay, A.; Haislip, J. B.; LaClutze, A. P.; Moore, J. P.; Reichart, D. E.

      2014-01-01

      A comprehensive set of optical and near-infrared (NIR) photometry and spectroscopy is presented for the faint and fast 2008ha-like supernova (SN) 2010ae. Contingent on the adopted value of host extinction, SN 2010ae reached a peak brightness of -13.8 > MV > -15.3 mag, while modeling of the UVOIR light curve suggests it produced 0.003-0.007 M⊙ of 56Ni, ejected 0.30-0.60 M⊙ of material, and had an explosion energy of 0.04-0.30 × 1051 erg. The values of these explosion parameters are similar to the peculiar SN 2008ha -for which we also present previously unpublished early phase optical and NIR light curves - and places these two transients at the faint end of the 2002cx-like SN population. Detailed inspection of the post-maximum NIR spectroscopic sequence indicates the presence of a multitude of spectral features, which are identified through SYNAPPS modeling to be mainly attributed to Co ii. Comparison with a collection of published and unpublished NIR spectra of other 2002cx-like SNe, reveals that a Co ii footprint is ubiquitous to this subclass of transients, providing a link to Type Ia SNe. A visual-wavelength spectrum of SN 2010ae obtained at +252 days past maximum shows a striking resemblance to a similar epoch spectrum of SN 2002cx. However, subtle differences in the strength and ratio of calcium emission features, as well as diversity among similar epoch spectra of other 2002cx-like SNe indicates a range of physical conditions of the ejecta, highlighting the heterogeneous nature of thispeculiar class of transients. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programs 082.A-0526, 084.D-0719, 088.D-0222, 184.D-1140, and 386.D-0966); the Gemini Observatory, Cerro Pachon, Chile (Gemini Programs GS-2010A-Q-14 and GS-2010A-Q-38); the Magellan 6.5 m telescopes at Las Campanas Observatory; and the SOAR telescope.Tables 1-5 and Appendix A are available in electronic form at http

    2. A Near-Infrared Search for Hidden Broad-Line Regions in Ultraluminous Infrared Galaxies

      NASA Astrophysics Data System (ADS)

      Veilleux, Sylvain; Sanders, D. B.; Kim, D.-C.

      1997-07-01

      We report the results of a sensitive new near-infrared search for hidden broad-line regions (BLRs: ΔVFWHM >~ 2000 km s-1) in a sample of 25 ultraluminous infrared galaxies (ULIGs) selected for their lack of BLRs at optical wavelengths. These objects constitute a representative subset of the (non-Seyfert 1) 1 Jy sample of 111 ULIGs (Kim & Sanders), both in terms of their redshift and infrared luminosity distributions. In contrast to previous studies of ULIGs at lower redshift, the redshifts for our current subsample (z ~ 0.1-0.2) allow us to search for broad-line emission from the strong Paα λ1.8751 μm and [Si VI] λ1.962 μm emission lines, two powerful AGN diagnostic lines which are generally inaccessible in lower redshift objects. Broad Paα emission is detected for the first time in two sources--PKS 1345+12, F23499+2423 (object names that begin with ``F'' are sources identified in the IRAS Faint Source Catalog, Version 2), and the presence of a hidden BLR is confirmed in two additional sources--F20460+1925, F23060+0505. Broad Paα emission may also be present in three other sources--F08559+1053, F17179+5444, F23233+2817--but new data are needed to make sure that H2 λλ1.8665, 1.8721 is not contributing to this excess emission. In addition, the [Si VI] feature appears to be present in three objects--F12072-0444, PKS 1345+12, F23233+2817--and perhaps also in F17179+5444. Combining our new data with previously published spectra for Mrk 463E, we find that all of the galaxies with evidence for a hidden BLR at near-infrared wavelengths present an optical Seyfert 2 spectrum. Overall, seven (and perhaps nine) of the 10 optical Seyfert 2 galaxies in our sample present either a BLR or strong [Si VI] emission. Also, galaxies with ``warm'' IRAS colors (f25/f60 > 0.2) (the quantities f25, f60 are the IRAS flux densities in Jy at 25 and 60 μm, respectively) show a tendency to harbor obscured BLRs in the near-infrared and to have large Paα-to-infrared luminosity ratios

    3. History of infrared detectors

      NASA Astrophysics Data System (ADS)

      Rogalski, A.

      2012-09-01

      This paper overviews the history of infrared detector materials starting with Herschel's experiment with thermometer on February 11th, 1800. Infrared detectors are in general used to detect, image, and measure patterns of the thermal heat radiation which all objects emit. At the beginning, their development was connected with thermal detectors, such as thermocouples and bolometers, which are still used today and which are generally sensitive to all infrared wavelengths and operate at room temperature. The second kind of detectors, called the photon detectors, was mainly developed during the 20th Century to improve sensitivity and response time. These detectors have been extensively developed since the 1940's. Lead sulphide (PbS) was the first practical IR detector with sensitivity to infrared wavelengths up to ˜3 μm. After World War II infrared detector technology development was and continues to be primarily driven by military applications. Discovery of variable band gap HgCdTe ternary alloy by Lawson and co-workers in 1959 opened a new area in IR detector technology and has provided an unprecedented degree of freedom in infrared detector design. Many of these advances were transferred to IR astronomy from Departments of Defence research. Later on civilian applications of infrared technology are frequently called "dual-use technology applications." One should point out the growing utilisation of IR technologies in the civilian sphere based on the use of new materials and technologies, as well as the noticeable price decrease in these high cost technologies. In the last four decades different types of detectors are combined with electronic readouts to make detector focal plane arrays (FPAs). Development in FPA technology has revolutionized infrared imaging. Progress in integrated circuit design and fabrication techniques has resulted in continued rapid growth in the size and performance of these solid state arrays.

    4. A Keck/DEIMOS spectroscopic survey of faint Galactic satellites: searching for the least massive dwarf galaxies

      NASA Astrophysics Data System (ADS)

      Martin, N. F.; Ibata, R. A.; Chapman, S. C.; Irwin, M.; Lewis, G. F.

      2007-09-01

      We present the results of a spectroscopic survey of the recently discovered faint Milky Way satellites Boötes, Ursa Major I, Ursa Major II and Willman 1 (Wil1). Using the DEep Imaging Multi-Object Spectrograph mounted on the Keck II telescope, we have obtained samples that contain from ~15 to ~85 probable members of these satellites for which we derive radial velocities precise to a few kms-1 down to i ~ 21-22. About half of these stars are observed with a high enough signal-to-noise ratio to estimate their metallicity to within +/-0.2 dex. The characteristics of all the observed stars are made available, along with those of the Canes Venatici I dwarf galaxy that have been analysed in a companion paper. From this data set, we show that Ursa Major II is the only object that does not show a clear radial velocity peak. However, the measured systemic radial velocity (vr = 115 +/- 5kms-1) is in good agreement with simulations in which this object is the progenitor of the recently discovered Orphan Stream. The three other satellites show velocity dispersions that make them highly dark matter dominated systems (under the usual assumptions of symmetry and virial equilibrium). In particular, we show that despite its small size and faintness, the Wil1 object is not a globular cluster given its metallicity scatter over -2.0 <~ [Fe/H] <~ -1.0 and is therefore almost certainly a dwarf galaxy or dwarf galaxy remnant. We measure a radial velocity dispersion of only 4.3+2.3-1.3kms-1 around a systemic velocity of -12.3 +/- 2.3kms-1 which implies a mass-to-light ratio of ~700 and a total mass of ~5 × 105Msolar for this satellite, making it the least massive satellite galaxy known to date. Such a low mass could mean that the 107Msolar limit that had until now never been crossed for Milky Way and Andromeda satellite galaxies may only be an observational limit and that fainter, less massive systems exist within the Local Group. However, more modelling and an extended search for

    5. ARE THE FAINT STRUCTURES AHEAD OF SOLAR CORONAL MASS EJECTIONS REAL SIGNATURES OF DRIVEN SHOCKS?

      SciTech Connect

      Lee, Jae-Ok; Moon, Y.-J.; Lee, Kangjin; Lee, Jin-Yi; Lee, Kyoung-Sun; Kim, Sujin E-mail: moonyj@khu.ac.kr

      2014-11-20

      Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observatory/Large Angle Spectroscopic COronagraph (LASCO) front-side halo (partial and full) CMEs near the limb from 1997 to 2011. We classify these CMEs into two groups by visual inspection of CMEs in the LASCO-C2 field of view: Group 1 has the faint structure ahead of a CME and Group 2 does not have such a structure. We find the following results. (1) Eighty-seven CMEs belong to Group 1 and 40 CMEs belong to Group 2. (2) Group 1 events have much higher speeds (average = 1230 km s{sup –1} and median = 1199 km s{sup –1}) than Group 2 events (average = 598 km s{sup –1} and median = 518 km s{sup –1}). (3) The fraction of CMEs with faint structures strongly depends on CME speeds (V): 0.93 (50/54) for fast CMEs with V ≥ 1000 km s{sup –1}, 0.65 (34/52) for intermediate CMEs with 500 km s{sup –1} ≤ V < 1000 km s{sup –1}, and 0.14 (3/21) for slow CMEs with V < 500 km s{sup –1}. We also find that the fraction of CMEs with deca-hecto metric type II radio bursts is consistent with the above tendency. Our results indicate that the observed faint structures ahead of fast CMEs are most likely an enhanced density manifestation of CME-driven shocks.

    6. Faint Radio Sources in the NOAO Boötes Field: VLBA Imaging and Optical Identifications

      NASA Astrophysics Data System (ADS)

      Wrobel, J. M.; Taylor, G. B.; Rector, T. A.; Myers, S. T.; Fassnacht, C. D.

      2005-09-01

      As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0 GHz to obtain phase-referenced images of 76 sources in the NOAO Boötes field. These 76 sources were selected from the Faint Images of the Radio Sky at Twenty cm (FIRST) catalog to have peak flux densities above 10 mJy at 5" resolution and deconvolved major diameters of less than 3" at 1.4 GHz. Of these faint radio sources, 57 were identified with accretion-powered radio galaxies and quasars brighter than 25.5 mag in the optical I band. On Very Large Array (VLA) scales at 1.4 GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NRAO VLA Sky Survey catalog) spans the full range of possibilities arising from source-resolution effects. Of the faint radio sources, 30, or 39+9-7%, were detected with the VLBA at 5.0 GHz with peak flux densities above 6 σ~2 mJy at 2 mas resolution. The VLBA detections occur through the full range of compactness ratios. The stronger VLBA detections can themselves serve as phase-reference calibrators, boding well for opening up much of the radio sky to VLBA imaging. For the adopted cosmology, the VLBA resolution corresponds to 17 pc or finer. Most VLBA detections are unresolved or slightly resolved, but one is diffuse and five show either double or core-jet structures; the properties of these latter six are discussed in detail. Three VLBA detections are unidentified and fainter than 25.5 mag in the optical I band; their properties are highlighted because they likely mark optically obscured active nuclei at high redshift.

    7. Constraints on Photoionization Feedback from Number Counts of Ultra-faint High-redshift Galaxies in the Frontier Fields

      NASA Astrophysics Data System (ADS)

      Castellano, M.; Yue, B.; Ferrara, A.; Merlin, E.; Fontana, A.; Amorín, R.; Grazian, A.; Mármol-Queralto, E.; Michałowski, M. J.; Mortlock, A.; Paris, D.; Parsa, S.; Pilo, S.; Santini, P.

      2016-06-01

      We exploit a sample of ultra-faint high-redshift galaxies (demagnified Hubble Space Telescope, HST, H 160 magnitude > 30) in the Frontier Fields clusters A2744 and M0416 to constrain a theoretical model for the UV luminosity function in the presence of photoionization feedback. The objects have been selected on the basis of accurate photometric redshifts computed from multi-band photometry including seven HST bands and deep K s and IRAC observations. Magnification is computed on an object-by-object basis from all available lensing models of the two clusters. We take into account source detection completeness as a function of luminosity and size, magnification effects, and systematics in the lens modeling of the clusters under investigation. We find that our sample of high-z galaxies constrain the cutoff halo circular velocity below which star formation is suppressed by photoionization feedback to {v}c{{cut}}\\lt 50 km s‑1. This circular velocity corresponds to a halo mass of ≈5.6 × 109 M ⊙ and ≈2.3 × 109 M ⊙ at z = 5 and 10, respectively: higher-mass halos can thus sustain continuous star formation activity without being quenched by external ionizing flux. More stringent constraints are prevented by the uncertainty in the modeling of the cluster lens, as embodied by systematic differences among the lens models available.

    8. Why Infrared?

      ERIC Educational Resources Information Center

      Harris, J. R.

      1973-01-01

      Discusses applications of techniques developed for the remote sensing of infrared radiation. In addition to military applications, remote sensing has become important in collecting environmental data and detecting ecological problems. (JR)

    9. Intensity Mapping of the History of Stellar Emission with the Cosmic Infrared Background ExpeRiment-2

      NASA Astrophysics Data System (ADS)

      Lanz, Alicia E.; Arai, Toshiaki; Battle, John; Bock, James; Cooray, Asantha R.; Hristov, Viktor; Korngut, Phillip; Lee, Dae Hee; Mason, Peter; Matsumoto, Toshio; Matsuura, Shuji; Onishi, Yosuke; Shirahata, Mai; Tsumurai, Kohji; Wada, Takehiko; Zemcov, Michael B.

      2016-01-01

      Recent measurements of the near-infrared Extragalactic Background Light (EBL) anisotropy find excess spatial power above the level predicted by known galaxy populations at large angular scales. These anisotropies trace spatial variations in integrated photon production, so measurements of EBL surface brightness fluctuations provide a complete census of the emission from stars summed over cosmic history. As a result, EBL fluctuations contain contributions from objects forming during the Epoch of Reionization (EOR), from the integrated galactic light (IGL), and faint, extended components such as intra-halo light (IHL) from stars tidally stripped from galaxies during merger events. Additional measurements with greater sensitivity, spectral range, and spectral resolution are required to disentangle these contributions.The Cosmic Infrared Background ExpeRiment 2 (CIBER-2) is an instrument optimized for the measurement of near-infrared EBL anisotropies. As the Earth's atmosphere generates time-varying near-infrared emission, CIBER-2 is launched on a sounding rocket from which it will carry out multiwavelength imaging in six spectral bands that span the visible to near-infrared. The 2.4 square degree images allow CIBER-2 to produce measurements of EBL fluctuations with high fidelity on large angular scales. The Lyman break feature from EOR sources provides a unique spectral feature which can be used to disentangle the high from the low redshift contributions to the anisotropy signal. Measurement in six independent wavebands allows detailed cross-correlation studies to constrain the source of the excess fluctuations at large angular scales. We provide an overview of the CIBER-2 instrument and explain CIBER-2 spectral feature identification and cross-correlation study methodologies.

    10. The near-infrared counterpart of a variable galactic plane radio source

      NASA Technical Reports Server (NTRS)

      Margon, Bruce; Phillips, Andrew C.; Ciardullo, Robin; Jacoby, George H.

      1992-01-01

      A near-infrared counterpart to the highly variable, unresolved galactic plane radio source GT 0116 + 622 is identified. This source is of particular interest, as it has been previously suggested to be the counterpart of the gamma-ray source Cas gamma-l. The present NIR and red images detect a faint, spatially extended (3 arcsec FWHM), very red object coincident with the radio position. There is complex spatial structure which may be due in part to an unrelated superposed foreground object. Observations on multiple nights show no evidence for flux variability, despite the high amplitude variability on a time-scale of days reported for the radio source. The data are consistent with an interpretation of GT 0116 + 622 as an unusually variable, obscured active galaxy at a distance of several hundred megaparsecs, although more exotic, and in particular galactic, interpretations cannot yet be ruled out. If the object is extragalactic, the previously suggested identification with the gamma-ray source would seem unlikely.

    11. Adaptive Objectness for Object Tracking

      NASA Astrophysics Data System (ADS)

      Liang, Pengpeng; Pang, Yu; Liao, Chunyuan; Mei, Xue; Ling, Haibin

      2016-07-01

      Object tracking is a long standing problem in vision. While great efforts have been spent to improve tracking performance, a simple yet reliable prior knowledge is left unexploited: the target object in tracking must be an object other than non-object. The recently proposed and popularized objectness measure provides a natural way to model such prior in visual tracking. Thus motivated, in this paper we propose to adapt objectness for visual object tracking. Instead of directly applying an existing objectness measure that is generic and handles various objects and environments, we adapt it to be compatible to the specific tracking sequence and object. More specifically, we use the newly proposed BING objectness as the base, and then train an object-adaptive objectness for each tracking task. The training is implemented by using an adaptive support vector machine that integrates information from the specific tracking target into the BING measure. We emphasize that the benefit of the proposed adaptive objectness, named ADOBING, is generic. To show this, we combine ADOBING with seven top performed trackers in recent evaluations. We run the ADOBING-enhanced trackers with their base trackers on two popular benchmarks, the CVPR2013 benchmark (50 sequences) and the Princeton Tracking Benchmark (100 sequences). On both benchmarks, our methods not only consistently improve the base trackers, but also achieve the best known performances. Noting that the way we integrate objectness in visual tracking is generic and straightforward, we expect even more improvement by using tracker-specific objectness.

    12. SIRTF - The Space Infrared Telescope Facility

      NASA Technical Reports Server (NTRS)

      Werner, Michael W.; Eisenhardt, Peter

      1988-01-01

      The complexity and variety of objects in the infrared universe have been revealed by the Infrared Astronomical Satellite (IRAS). Further exploration of this universe will be possible with the Space Infrared Telescope Facility (SIRTF), which offers vast improvements in sensitivity and resolution over IRAS. SIRTF's planned capabilities and current status are briefly reviewed.

    13. Near-Infrared Photon-Counting Camera for High-Sensitivity Observations

      NASA Technical Reports Server (NTRS)

      Jurkovic, Michael

      2012-01-01

      The dark current of a transferred-electron photocathode with an InGaAs absorber, responsive over the 0.9-to-1.7- micron range, must be reduced to an ultralow level suitable for low signal spectral astrophysical measurements by lowering the temperature of the sensor incorporating the cathode. However, photocathode quantum efficiency (QE) is known to reduce to zero at such low temperatures. Moreover, it has not been demonstrated that the target dark current can be reached at any temperature using existing photocathodes. Changes in the transferred-electron photocathode epistructure (with an In- GaAs absorber lattice-matched to InP and exhibiting responsivity over the 0.9- to-1.7- m range) and fabrication processes were developed and implemented that resulted in a demonstrated >13x reduction in dark current at -40 C while retaining >95% of the approximately equal to 25% saturated room-temperature QE. Further testing at lower temperature is needed to confirm a >25 C predicted reduction in cooling required to achieve an ultralow dark-current target suitable for faint spectral astronomical observations that are not otherwise possible. This reduction in dark current makes it possible to increase the integration time of the imaging sensor, thus enabling a much higher near-infrared (NIR) sensitivity than is possible with current technology. As a result, extremely faint phenomena and NIR signals emitted from distant celestial objects can be now observed and imaged (such as the dynamics of redshifting galaxies, and spectral measurements on extra-solar planets in search of water and bio-markers) that were not previously possible. In addition, the enhanced NIR sensitivity also directly benefits other NIR imaging applications, including drug and bomb detection, stand-off detection of improvised explosive devices (IED's), Raman spectroscopy and microscopy for life/physical science applications, and semiconductor product defect detection.

    14. Discovery of the candidate Kuiper belt object 1992 QB1

      NASA Technical Reports Server (NTRS)

      Jewitt, David; Luu, Jane

      1993-01-01

      The discovery of a new faint object in the outer solar system, 1992 QB1, moving beyond the orbit of Neptune is reported. It is suggested that the 1992 QB1 may represent the first detection of a member of the Kuiper belt (Edgworth, 1949; Kuiper, 1951), the hypothesized population of objects beyond Neptune and a possible source of the short-period comets, as suggested by Whipple (1964), Fernandez (1980), and Duncan et al. (1988).

    15. Love Objects.

      ERIC Educational Resources Information Center

      Cusack, Lynne

      1998-01-01

      Discusses the role of "security" or "transition" objects, such as a blanket or stuffed toy, in children's development of self-comfort and autonomy. Notes the influence of parents in the child-object relationship, and discusses children's responses to losing a security object, and the developmental point at which a child will give up such an…

    16. THE EVOLUTION OF THE REST-FRAME V-BAND LUMINOSITY FUNCTION FROM z = 4: A CONSTANT FAINT-END SLOPE OVER THE LAST 12 Gyr OF COSMIC HISTORY

      SciTech Connect

      Marchesini, Danilo; Stefanon, Mauro; Whitaker, Katherine E.

      2012-04-01

      We present the rest-frame V-band luminosity function (LF) of galaxies at 0.4 {<=} z < 4.0, measured from a near-infrared selected sample constructed from the NMBS, the FIRES, the FIREWORKS, and the ultra-deep NICMOS and WFC3 observations in the HDFN, HUDF, and GOODS-CDFS, all having high-quality optical-to-mid-infrared data. This unique sample combines data from surveys with a large range of depths and areas in a self-consistent way, allowing us to (1) minimize the uncertainties due to cosmic variance; and (2) simultaneously constrain the bright and faint ends with unprecedented accuracy over the targeted redshift range, probing the LF down to 0.1L* at z {approx} 3.9. We find that (1) the faint end is fairly flat and with a constant slope from z = 4, with {alpha} = -1.27 {+-} 0.05; (2) the characteristic magnitude has dimmed by 1.3 mag from z {approx} 3.7 to z = 0.1; (3) the characteristic density has increased by a factor of {approx}8 from z {approx} 3.7 to z = 0.1, with 50% of this increase from z {approx} 4 to z {approx} 1.8; and (4) the luminosity density peaks at z Almost-Equal-To 1-1.5, increasing by a factor of {approx}4 from z = 4.0 to z Almost-Equal-To 1-1.5, and subsequently decreasing by a factor of {approx}1.5 by z = 0.1. We find no evidence for a steepening of the faint-end slope with redshift out to z = 4, in contrast with previous observational claims and theoretical predictions. The constant faint-end slope suggests that the efficiency of stellar feedback may evolve with redshift. Alternative interpretations are discussed, such as different masses of the halos hosting faint galaxies at low and high redshifts and/or environmental effects.

    17. Occultations of stars by solar system objects. III - A photographic search for occultations of faint stars by selected asteroids

      NASA Astrophysics Data System (ADS)

      Millis, R. L.; Franz, O. G.; Wasserman, L. H.; Bowell, E.

      1983-02-01

      Occultations of stars fainter than the AGK and SAO catalog limits by selected minor planets during their 1983 apparitions have been identified by scanning plates taken with the 13-in. Lowell astrograph. A total of 33 upcoming occultations have been found involving 1 Ceres, 10 Hygiea, 52 Europa, 65 Cybele, 451 Patientia, 511 Davida, and 704 Interamnia.

    18. THE SUBARU HIGH-z QUASAR SURVEY: DISCOVERY OF FAINT z ∼ 6 QUASARS

      SciTech Connect

      Kashikawa, Nobunari; Furusawa, Hisanori; Niino, Yuu; Ishizaki, Yoshifumi; Onoue, Masafusa; Toshikawa, Jun; Ishikawa, Shogo; Willott, Chris J.; Im, Myungshin; Shimasaku, Kazuhiro; Ouchi, Masami; Hibon, Pascale

      2015-01-01

      We present the discovery of one or two extremely faint z ∼ 6 quasars in 6.5 deg{sup 2} utilizing a unique capability of the wide-field imaging of the Subaru/Suprime-Cam. The quasar selection was made in (i'-z{sub B} ) and (z{sub B} -z{sub R} ) colors, where z{sub B} and z{sub R} are bandpasses with central wavelengths of 8842 Å and 9841 Å, respectively. The color selection can effectively isolate quasars at z ∼ 6 from M/L/T dwarfs without the J-band photometry down to z{sub R} < 24.0, which is 3.5 mag deeper than the Sloan Digital Sky Survey (SDSS). We have selected 17 promising quasar candidates. The follow-up spectroscopy for seven targets identified one apparent quasar at z = 6.156 with M {sub 1450} = –23.10. We also identified one possible quasar at z = 6.041 with a faint continuum of M {sub 1450} = –22.58 and a narrow Lyα emission with HWHM =427 km s{sup –1}, which cannot be distinguished from Lyman α emitters. We derive the quasar luminosity function at z ∼ 6 by combining our faint quasar sample with the bright quasar samples by SDSS and CFHQS. Including our data points invokes a higher number density in the faintest bin of the quasar luminosity function than the previous estimate employed. This suggests a steeper faint-end slope than lower z, though it is yet uncertain based on a small number of spectroscopically identified faint quasars, and several quasar candidates still remain to be diagnosed. The steepening of the quasar luminosity function at the faint end does increase the expected emission rate of the ionizing photon; however, it only changes by a factor of approximately two to six. This was found to still be insufficient for the required photon budget of reionization at z ∼ 6.

    19. The Faint End of the Quasar Luminosity Function at z ~ 4

      NASA Astrophysics Data System (ADS)

      Glikman, Eilat; Bogosavljević, Milan; Djorgovski, S. G.; Stern, Daniel; Dey, Arjun; Jannuzi, Buell T.; Mahabal, Ashish

      2010-02-01

      The evolution of the quasar luminosity function (QLF) is one of the basic cosmological measures providing insight into structure formation and mass assembly in the universe. We have conducted a spectroscopic survey to find faint quasars (-26.0 < M 1450 < -22.0) at redshifts z = 3.8-5.2 in order to measure the faint end of the QLF at these early times. Using available optical imaging data from portions of the NOAO Deep Wide-Field Survey and the Deep Lens Survey, we have color-selected quasar candidates in a total area of 3.76 deg2. Thirty candidates have R <= 23 mag. We conducted spectroscopic follow-up for 28 of our candidates and found 23 QSOs, 21 of which are reported here for the first time, in the 3.74 < z < 5.06 redshift range. We estimate our survey completeness through detailed Monte Carlo simulations and derive the first measurement of the density of quasars in this magnitude and redshift interval. We find that the binned luminosity function (LF) is somewhat affected by the K-correction used to compute the rest-frame absolute magnitude at 1450 Å. Considering only our R <= 23 sample, the best-fit single power law (Φ vprop L β) gives a faint-end slope β = -1.6 ± 0.2. If we consider our larger, but highly incomplete sample going 1 mag fainter, we measure a steeper faint-end slope -2 < β < -2.5. In all cases, we consistently find faint-end slopes that are steeper than expected based on measurements at z ~ 3. We combine our sample with bright quasars from the Sloan Digital Sky Survey to derive parameters for a double-power-law LF. Our best fit finds a bright-end slope, α = -2.4 ± 0.2, and faint-end slope, β = -2.3 ± 0.2, without a well-constrained break luminosity. This is effectively a single power law, with β = -2.7 ± 0.1. We use these results to place limits on the amount of ultraviolet radiation produced by quasars and find that quasars are able to ionize the intergalactic medium at these redshifts. The data presented herein were obtained at the

    20. A faint galaxy redshift survey behind massive clusters

      SciTech Connect

      Frye, Brenda

      1999-12-01

      This thesis is concerned with the gravitational lensing effect by massive galaxy clusters. We have explored a new technique for measuring galaxy masses and for detecting high-z galaxies by their optical colors. A redshift survey has been obtained at the Keck for a magnitude limited sample of objects (I<23) behind three clusters, A1689, A2390, and A2218 within a radius of 0.5M pc. For each cluster we see both a clear trend of increasing flux and redshift towards the center. This behavior is the result of image magnifications, such that at fixed redshift one sees further down the luminosity function. The gradient of this magnification is, unlike measurements of image distortion, sensitive to the mass profile, and found to depart strongly from a pure isothermal halo. We have found that V RI color selection can be used effectively as a discriminant for finding high-z galaxies behind clusters and present five 4.1 < z < 5.1 spectra which are of very high quality due to their high mean magnification of {approximately}20, showing strong, visibly-saturated interstellar metal lines in some cases. We have also investigated the radio ring lens PKS 1830-211, locating the source and multiple images and detected molecular absorption at mm wavelengths. Broad molecular absorption of width 1/40kms is found toward the southwest component only, where surprisingly it does not reach the base of the continuum, which implies incomplete coverage of the SW component by molecular gas, despite the small projected size of the source, less than 1/8h pc at the absorption redshift.

    1. TRENDS: Compendium of Benchmark Objects

      NASA Astrophysics Data System (ADS)

      Gonzales, Erica J.; Crepp, Justin R.; Bechter, Eric; Johnson, John A.; Montet, Benjamin T.; Howard, Andrew; Marcy, Geoffrey W.; Isaacson, Howard T.

      2016-01-01

      The physical properties of faint stellar and substellar objects are highly uncertain. For example, the masses of brown dwarfs are usually inferred using theoretical models, which are age dependent and have yet to be properly tested. With the goal of identifying new benchmark objects through observations with NIRC2 at Keck, we have carried out a comprehensive adaptive-optics survey as part of the TRENDS (TaRgetting bENchmark-objects with Doppler Spectroscopy) high-contrast imaging program. TRENDS targets nearby (d < 100 pc), Sun-like stars showing long-term radial velocity accelerations. We present the discovery of 28 confirmed, co-moving companions as well as 19 strong candidate companions to F-, G-, and K-stars with well-determined parallaxes and metallicities. Benchmark objects of this nature lend themselves to a three dimensional orbit determination that will ultimately yield a precise dynamical mass. Unambiguous mass measurements of very low mass companions, which straddle the hydrogen-burning boundary, will allow our compendium of objects to serve as excellent testbeds to substantiate theoretical evolutionary and atmospheric models in regimes where they currently breakdown (low temperature, low mass, and old age).

    2. Faint recombination lines in Galactic PNe with a [WC] nucleus

      NASA Astrophysics Data System (ADS)

      García-Rojas, J.; Peña, M.; Peimbert, A.

      2009-03-01

      Aims: We present spatially resolved high-resolution spectrophotometric data for the planetary nebulae PB 8, NGC 2867, and PB 6. We have analyzed two knots in NGC 2867 and PB 6 and one in PB 8. The three nebulae are ionized by [WC] type nuclei: early [WO] for PB 6 and NGC 2867 and [WC 5-6] in the case of PB 8. Our aim is to study the behavior of the abundance discrepancy problem (ADF) in this type of planetary nebula. Methods: We measured a large number of optical recombination (ORL) and collisionally excited lines (CEL), from different ionization stages (many more than in any previous work), thus, we were able to derive physical conditions from many different diagnostic procedures. We determined ionic abundances from the available collisionally excited and recombination lines. Based on both sets of ionic abundances, we derived total chemical abundances in the nebulae using suitable ionization correction factors. Results: From CELs, we have found abundances typical of Galactic disk planetary nebulae. Moderate ADF(O++) were found for PB 8 (2.57) and NGC 2867 (1.63). For NGC 2867, abundances from ORLs are higher but still consistent with Galactic disk planetary nebulae. On the contrary, PB 8 presents a very high O/H ratio from ORLs. A high C/O was obtained from ORLs for NGC 2867; this ratio is similar to C/O obtained from CELs and with the chemical composition of the wind of the central star, indicating that there was no further C-enrichment in the star, relative to O, after the nebular material ejection. On the contrary, we found C/O<1 in PB 8. Interestingly, we obtain (C/O)ORLs/(C/O)CELs < 1 in PB 8 and NGC 2867; this added to the similarity between the heliocentric velocities measured in [O iii] and O ii lines for our three objects argue against the presence of H-deficient metal-rich knots coming from a late thermal pulse event. Based on data obtained at Las Campanas Observatory, Carnegie Institution. Table 3 is only available in electronic form at http://www.aanda.org

    3. The Faint End of the Quasar Luminosity Function at z ~ 4: Implications for Ionization of the Intergalactic Medium and Cosmic Downsizing

      NASA Astrophysics Data System (ADS)

      Glikman, Eilat; Djorgovski, S. G.; Stern, Daniel; Dey, Arjun; Jannuzi, Buell T.; Lee, Kyoung-Soo

      2011-02-01

      We present an updated determination of the z ~ 4 QSO luminosity function (QLF), improving the quality of the determination of the faint end of the QLF presented by Glikman et al. (2010). We have observed an additional 43 candidates from our survey sample, yielding one additional QSO at z = 4.23 and increasing the completeness of our spectroscopic follow-up to 48% for candidates brighter than R = 24 over our survey area of 3.76 deg2. We study the effect of using K-corrections to compute the rest-frame absolute magnitude at 1450 Å compared with measuring M 1450 directly from the object spectra. We find a luminosity-dependent bias: template-based K-corrections overestimate the luminosity of low-luminosity QSOs, likely due to their reliance on templates derived from higher luminosity QSOs. Combining our sample with bright quasars from the Sloan Digital Sky Survey and using spectrum-based M 1450 for all the quasars, we fit a double power law to the binned QLF. Our best fit has a bright-end slope, α = 3.3 ± 0.2, and faint-end slope, β = 1.6+0.8 -0.6. Our new data revise the faint-end slope of the QLF down to flatter values similar to those measured at z ~ 3. The break luminosity, though poorly constrained, is at M* = -24.1+0.7 -1.9, approximately 1-1.5 mag fainter than at z ~ 3. This QLF implies that QSOs account for about half the radiation needed to ionize the intergalactic medium at these redshifts. 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.

    4. Ground based infrared astronomy

      NASA Technical Reports Server (NTRS)

      Jennings, D. E.

      1988-01-01

      Infrared spectroscopic instrumentation has been developed for ground-based measurements of astrophysical objects in the intermediate infrared. A conventional Michelson interferometer is limited for astronomical applications in the intermediate infrared by quantum noise fluctuations in the radiation form the source and/or background incident on the detector, and the multiplex advantage is no longer available. One feasible approach to recovering the multiplex advantage is post-dispersion. The infrared signal after passing through telescope and interferometer, is dispersed by a low resolution grating spectrometer onto an array of detectors. The feasibility of the post-dispersion system has been demonstrated with observations of astrophysical objects in the 5 and 10 micrometer atmospheric windows from ground-based telescopes. During FY87/88 the post-disperser was used at the Kitt Peak 4-meter telescope and McMath telescope with facility Fourier transform spectrometers. Jupiter, Saturn, Mars, and Venus were observed. On Jupiter, the resolution at 12 micrometer was 0.01/cm, considerably higher than had been acheived previously. The spectrum contains Jovian ethane and acetylene emission. Construction was begun on the large cryogenic grating spectrometer.

    5. Infrared Camera

      NASA Technical Reports Server (NTRS)

      1997-01-01

      A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.

    6. The Taiwan ECDFS Near-Infrared Survey: Ultra-deep J and KS Imaging in the Extended Chandra Deep Field-South

      NASA Astrophysics Data System (ADS)

      Hsieh, Bau-Ching; Wang, Wei-Hao; Hsieh, Chih-Chiang; Lin, Lihwai; Yan, Haojing; Lim, Jeremy; Ho, Paul T. P.

      2012-12-01

      We present ultra-deep J and KS imaging observations covering a 30' × 30' area of the Extended Chandra Deep Field-South (ECDFS) carried out by our Taiwan ECDFS Near-Infrared Survey (TENIS). The median 5σ limiting magnitudes for all detected objects in the ECDFS reach 24.5 and 23.9 mag (AB) for J and KS , respectively. In the inner 400 arcmin2 region where the sensitivity is more uniform, objects as faint as 25.6 and 25.0 mag are detected at 5σ. Thus, this is by far the deepest J and KS data sets available for the ECDFS. To combine TENIS with the Spitzer IRAC data for obtaining better spectral energy distributions of high-redshift objects, we developed a novel deconvolution technique (IRACLEAN) to accurately estimate the IRAC fluxes. IRACLEAN can minimize the effect of blending in the IRAC images caused by the large point-spread functions and reduce the confusion noise. We applied IRACLEAN to the images from the Spitzer IRAC/MUSYC Public Legacy in the ECDFS survey (SIMPLE) and generated a J+KS -selected multi-wavelength catalog including the photometry of both the TENIS near-infrared and the SIMPLE IRAC data. We publicly release the data products derived from this work, including the J and KS images and the J+KS -selected multi-wavelength catalog.

    7. Infrared Thermometer

      NASA Technical Reports Server (NTRS)

      1991-01-01

      Diatek Corporation, San Diego, CA and the Jet Propulsion Lab developed the Diatek Model 7000 aural thermometer which weighs only eight ounces, and measures temperature in less than two seconds using infrared astronomy technology to measure the amount of infrared energy emitted by the eardrum (the same way temperature of stars and planets is measured). This method avoids contact with mucous membranes, virtually eliminating the possibility of cross infection, and permits temperature measurement of newborn, critically ill, or incapacitated patients. Diatek Corporation was purchased by Welch Allyn Inc. The Diatek Model 7000 is now marketed as SureTemp.

    8. Infrared Scanning

      NASA Technical Reports Server (NTRS)

      1987-01-01

      United Scanning Technologies, Inc.'s Infrared thermography is a relatively new noncontact, nondestructive inspection and testing tool which makes temperatures visible to the human eye. Infrared scanning devices produce images that show, by color or black and white shading differences, heat losses through damaged or inadequately insulated walls or roofs. The MISS Aeroscan services are designed to take the guesswork out of industrial roof maintenance and provide companies big savings by identifying the location of moisture damage from roof leaks, effectively targeting maintenance attention.

    9. Infrared astronomy

      NASA Technical Reports Server (NTRS)

      Gillett, Frederick; Houck, James; Bally, John; Becklin, Eric; Brown, Robert Hamilton; Draine, Bruce; Frogel, Jay; Gatley, Ian; Gehrz, Robert; Hildebrand, Roger

      1991-01-01

      The decade of 1990's presents an opportunity to address fundamental astrophysical issues through observations at IR wavelengths made possible by technological and scientific advances during the last decade. The major elements of recommended program are: the Space Infrared Telescope Facility (SIRTF), the Stratospheric Observatory For Infrared Astronomy (SOFIA) and the IR Optimized 8-m Telescope (IRO), a detector and instrumentation program, the SubMilliMeter Mission (SMMM), the 2 Microns All Sky Survey (2MASS), a sound infrastructure, and technology development programs. Also presented are: perspective, science opportunities, technical overview, project recommendations, future directions, and infrastructure.

    10. BIG FISH, LITTLE FISH: TWO NEW ULTRA-FAINT SATELLITES OF THE MILKY WAY

      SciTech Connect

      Belokurov, V.; Walker, M. G.; Evans, N. W.; Gilmore, G.; Irwin, M. J.; Koposov, S.; Watkins, L.; Wyrzykowski, L.; Just, D.; Olszewski, E.; Mateo, M. E-mail: walker@ast.cam.ac.uk

      2010-03-20

      We report the discovery of two new Milky Way satellites in the neighboring constellations of Pisces and Pegasus identified in data from the Sloan Digital Sky Survey. Pisces II, an ultra-faint dwarf galaxy lies at the distance of {approx}180 kpc, some 15 deg. away from the recently detected Pisces I. Segue 3, an ultra-faint star cluster lies at the distance of 16 kpc. We use deep follow-up imaging obtained with the 4-m Mayall Telescope at Kitt Peak National Observatory to derive their structural parameters. Pisces II has a half-light radius of {approx}60 pc, while Segue 3 is 20 times smaller at only 3 pc.

    11. Variable Stars in the Field of the Hydra II Ultra-Faint Dwarf Galaxy

      NASA Astrophysics Data System (ADS)

      Vivas, Anna Katherina; Olsen, Knut A.; Blum, Robert D.; Nidever, David L.; Walker, Alistair R.; Martin, Nicolas; Besla, Gurtina; Gallart, Carme; Van Der Marel, Roeland P.; Majewski, Steven R.; Munoz, Ricardo; Kaleida, Catherine C.; Saha, Abhijit; Conn, Blair; Jin, Shoko

      2016-06-01

      We searched for variable stars in Hydra II, one of the recently discovered ultra-faint dwarf satellites of the Milky Way, using gri time-series obtained with the Dark Energy Camera (DECam) at Cerro Tololo Inter-American Observatory, Chile. We discovered one RR Lyrae star in the galaxy which was used to derive a distance of 154±8 kpc to this system and to re-calculate its absolute magnitude and half-light radius.A comparison with other RR Lyrae stars in ultra-faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid) which are likely not related with Hydra II.

    12. On the faint-end of the high-z galaxy luminosity function

      NASA Astrophysics Data System (ADS)

      Yue, Bin; Ferrara, Andrea; Xu, Yidong

      2016-08-01

      Recent measurements of the Luminosity Function (LF) of galaxies in the Epoch of Reionization (EoR, zlower.5ex buildrel> over ˜ 6) indicate a very steep increase of the number density of low-mass galaxies populating the LF faint-end. However, as star formation in low-mass halos can be easily depressed or even quenched by ionizing radiation, a turnover is expected at some faint UV magnitudes. Using a physically-motivated analytical model, we quantify reionization feedback effects on the LF faint-end shape. We find that if reionization feedback is neglected, the power-law Schechter parameterization characterizing the LF faint-end remains valid up to absolute UV magnitude ˜-9. If instead radiative feedback is strong enough that quenches star formation in halos with circular velocity smaller than 50 km s-1, the LF starts to drop at absolute UV magnitude ˜-15, i.e. slightly below the detection limits of current (unlensed) surveys at z ˜ 5. The LFs may rise again at higher absolute UV magnitude, where, as a result of interplay between reionization process and galaxy formation, most of the galaxy light is from relic stars formed before the EoR. We suggest that the galaxy number counts data, particularly in lensed fields, can put strong constraints on reionization feedback. In models with stronger reionization feedback, stars in galaxies with absolute UV magnitude higher than ˜-13 and smaller than ˜-8 are typically older. Hence, the stellar age - UV magnitude relation can be used as an alternative feedback probe.

    13. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

      SciTech Connect

      Drlica-Wagner, A.

      2015-11-04

      We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > -4.7 ) and span a range of physical sizes (17 pc < r1/2 < 181pc) and heliocentric distances (25 kpc < D < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ 27.5 mag arcsec -2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10-3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Furthermore, our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.

    14. Eight ultra-faint galaxy candidates discovered in year two of the Dark Energy Survey

      DOE PAGESBeta

      Drlica-Wagner, A.

      2015-11-04

      We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > -4.7 ) and span a range of physical sizes (17 pc < r1/2more » < 181pc) and heliocentric distances (25 kpc < D⊙ < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ 27.5 mag arcsec -2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10-3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Furthermore, our model predicts that the full sky may hold ~100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%–30% of these would be spatially associated with the Magellanic Clouds.« less

    15. Eight Ultra-faint Galaxy Candidates Discovered in Year Two of the Dark Energy Survey

      NASA Astrophysics Data System (ADS)

      Drlica-Wagner, A.; Bechtol, K.; Rykoff, E. S.; Luque, E.; Queiroz, A.; Mao, Y.-Y.; Wechsler, R. H.; Simon, J. D.; Santiago, B.; Yanny, B.; Balbinot, E.; Dodelson, S.; Fausti Neto, A.; James, D. J.; Li, T. S.; Maia, M. A. G.; Marshall, J. L.; Pieres, A.; Stringer, K.; Walker, A. R.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bernstein, G. M.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; da Costa, L. N.; Desai, S.; Diehl, H. T.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Evrard, A. E.; Finley, D. A.; Flaugher, B.; Fosalba, P.; Frieman, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; Kuehn, K.; Kuropatkin, N.; Lahav, O.; Martini, P.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Reil, K.; Roodman, A.; Sako, M.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Tucker, D.; Vikram, V.; Wester, W.; Zhang, Y.; Zuntz, J.; DES Collaboration

      2015-11-01

      We report the discovery of eight new ultra-faint dwarf galaxy candidates in the second year of optical imaging data from the Dark Energy Survey (DES). Six of these candidates are detected at high confidence, while two lower-confidence candidates are identified in regions of non-uniform survey coverage. The new stellar systems are found by three independent automated search techniques and are identified as overdensities of stars, consistent with the isochrone and luminosity function of an old and metal-poor simple stellar population. The new systems are faint (MV > -4.7 {mag}) and span a range of physical sizes (17 {pc} < r1/2 < 181 {pc}) and heliocentric distances (25 kpc < D⊙ < 214 kpc). All of the new systems have central surface brightnesses consistent with known ultra-faint dwarf galaxies (μ ≳ 27.5 {mag} {arcsec}-2). Roughly half of the DES candidates are more distant, less luminous, and/or have lower surface brightnesses than previously known Milky Way satellite galaxies. Most of the candidates are found in the southern part of the DES footprint close to the Magellanic Clouds. We find that the DES data alone exclude (p < 10-3) a spatially isotropic distribution of Milky Way satellites and that the observed distribution can be well, though not uniquely, described by an association between several of the DES satellites and the Magellanic system. Our model predicts that the full sky may hold ˜100 ultra-faint galaxies with physical properties comparable to the DES satellites and that 20%-30% of these would be spatially associated with the Magellanic Clouds.

    16. Faint Radio Sources in the NOAO Bootes Field. VLBA Imaging And Optical Identifications

      SciTech Connect

      Wrobel, J.M.; Taylor, Greg B.; Rector, T.A.; Myers, S.T.; Fassnacht, C.D.; /UC, Davis

      2005-06-13

      As a step toward investigating the parsec-scale properties of faint extragalactic radio sources, the Very Long Baseline Array (VLBA) was used at 5.0 GHz to obtain phase-referenced images of 76 sources in the NOAO Booetes field. These 76 sources were selected from the FIRST catalog to have peak flux densities above 10 mJy at 5'' resolution and deconvolved major diameters of less than 3'' at 1.4 GHz. Fifty-five of these faint radio sources were identified with accretion-powered radio galaxies and quasars brighter than 25.5 mag in the optical I band. On VLA scales at 1.4 GHz, a measure of the compactness of the faint sources (the ratio of the peak flux density from FIRST to the integrated flux density from the NVSS catalog) spans the full range of possibilities arising from source-resolution effects. Thirty of the faint radio sources, or 39{sub -7}{sup +9}%, were detected with the VLBA at 5.0 GHz with peak flux densities above 6 {sigma} {approx} 2 mJy at 2 mas resolution. The VLBA detections occur through the full range of compactness ratios. The stronger VLBA detections can themselves serve as phase-reference calibrators, boding well for opening up much of the radio sky to VLBA imaging. For the adopted cosmology, the VLBA resolution corresponds to 17 pc or finer. Most VLBA detections are unresolved or slightly resolved but one is diffuse and five show either double or core-jet structures; the properties of these latter six are discussed in detail. Eight VLBA detections are unidentified and fainter than 25.5 mag in the optical I band; their properties are highlighted because they likely mark optically-obscured active nuclei at high redshift.

    17. Prognosis of glioblastoma with faint MGMT methylation-specific PCR product.

      PubMed

      Hsu, Chih-Yi; Ho, Hsiang-Ling; Lin, Shih-Chieh; Chang-Chien, Yi-Chun; Chen, Ming-Hsiung; Hsu, Sanford Ping-Chuan; Yen, Yu-Shu; Guo, Wan-You; Ho, Donald Ming-Tak

      2015-03-01

      Methylation-specific polymerase chain reaction (MSP) for the promoter methylation status of O(6)-methylguanine-DNA-methyltranferase (MGMT) gene theoretically provides a positive or negative result. However, the faint MSP product is difficult to interpret. The aim of this study was to evaluate the significance of faint MSP product in glioblastoma (GBM). Critical concentrations of methylated control DNA, i.e., 100, 1, 0.5 and 0 % were run parallel with 116 newly diagnosed GBMs in order to standardize the interpretation and to distinguish positive (+), equivocal (±), and negative (-; unmethylated) results. Cases with the faint MSP product and its intensity between those of 1 and 0.5 % DNA controls were considered equivocal (±). MGMT methylation quantifications were also determined by quantitative real-time MSP (qMSP) and pyrosequencing (PSQ), and protein expression was detected by immunohistochemistry. There were significant correlations between MSP and all the aforementioned studies. The concordance rates between the MSP+ and qMSP+ cases, as well as the MSP- and qMSP- cases were 100 %, and the MSP± cases comprised 76.5 % of qMSP+ cases and 23.5 % of qMSP- cases. PSQ study showed that heterogeneous methylation was more frequently encountered in the MSP± cases. Multivariate analyses disclosed that although the overall survival of the MSP± cases was indistinct from that of the MSP+ cases, its progression free survival was significantly worse and was indistinct from that of the MSP- cases. In conclusion, GBMs with faint MGMT MSP products should be distinguished from MSP+ cases as their behaviors were different. PMID:25575938

    18. Faint electric treatment-induced rapid and efficient delivery of extraneous hydrophilic molecules into the cytoplasm.

      PubMed

      Hasan, Mahadi; Nishimoto, Akinori; Ohgita, Takashi; Hama, Susumu; Kashida, Hiromu; Asanuma, Hiroyuki; Kogure, Kentaro

      2016-04-28

      Effective delivery of extraneous molecules into the cytoplasm of the target cells is important for several drug therapies. Previously, we showed effective in vivo transdermal delivery of naked siRNA into skin cells induced by faint electric treatment (ET) iontophoresis, and significant suppression of target mRNA levels (Kigasawa et al., Int. J. Pharm., 2010). This result indicates that electricity promoted the delivery of siRNA into cytoplasm. In the present study, we analyzed the intracellular delivery of naked anti-luciferase siRNA by faint ET, and found that the luciferase activity of cells expressing luciferase was reduced by in vitro ET like in vivo iontophoresis. Cellular uptake of fluorescent-label siRNA was increased by ET, while low temperature exposure, macropinocytosis inhibitor amiloride and caveolae-mediated endocytosis inhibitor filipin significantly prevented siRNA uptake. These results indicate that the cellular uptake mechanism involved endocytosis. In addition, voltage sensitive fluorescent dye DiBAC4 (3) penetration was increased by ET, and the transient receptor potential channel inhibitor SKF96365 reduced siRNA uptake, suggesting that faint ET reduced membrane potentials by changing intracellular ion levels. Moreover, to analyze cytoplasmic delivery, we used in-stem molecular beacon (ISMB), which fluoresces upon binding to target mRNA in the cytoplasm. Surprisingly, cytoplasmic ISMB fluorescence appeared rapidly and homogeneously after ET, indicating that cytoplasmic delivery is markedly enhanced by ET. In conclusion, we demonstrated for the first time that faint ET can enhance cellular uptake and cytoplasmic delivery of extraneous molecules. PMID:26944781

    19. Objective lens

      NASA Technical Reports Server (NTRS)

      Olczak, Eugene G. (Inventor)

      2011-01-01

      An objective lens and a method for using same. The objective lens has a first end, a second end, and a plurality of optical elements. The optical elements are positioned between the first end and the second end and are at least substantially symmetric about a plane centered between the first end and the second end.

    20. Infrared Observations of the Quintuplet Proper Members using SOFIA/FORCAST and Gemini/TReCS

      NASA Astrophysics Data System (ADS)

      Hankins, M. J.; Lau, R. M.; Morris, M. R.; Sanchez-Bermudez, J.; Pott, J. U.; Adams, J. D.; Herter, T. L.

      2016-08-01

      Since their discovery, the Quintuplet proper members (QPMs) have been somewhat mysterious in nature. Originally dubbed the “cocoon stars” due to their cool featureless spectra, high-resolution near-infrared imaging observations have shown that at least two of the objects exhibit “pinwheel” nebulae consistent with binary systems with a carbon-rich Wolf–Rayet star and O/B companion. In this paper, we present 19.7, 25.2, 31.5, and 37.1 μm observations of the QPMs (with an angular resolution of 3.2″–3.8″) taken with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) in conjunction with high-resolution (˜0.1″–0.2″) images at 8.8 and 11.7 μm from the Thermal-Region Camera Spectrograph (TReCS). DUSTY models of the thermal dust emission of two of the four detected QPMs, Q2 and Q3, are fitted by radial density profiles that are consistent with constant mass-loss rates ({ρ }d\\propto {r}-2). For the two remaining sources, Q1 and Q9, extended structures (˜1″) are detected around these objects in high-resolution imaging data. Based on the fitted dust masses, Q9 has an unusually large dust reservoir ({M}{{d}}={1.3}-0.4+0.8× {10}-3{M}ȯ ) compared to typical dusty Wolf–Rayet stars, which suggests that it may have recently undergone an episode of enhanced mass loss.

    1. Infrared Observations of the Quintuplet Proper Members using SOFIA/FORCAST and Gemini/TReCS

      NASA Astrophysics Data System (ADS)

      Hankins, M. J.; Lau, R. M.; Morris, M. R.; Sanchez-Bermudez, J.; Pott, J. U.; Adams, J. D.; Herter, T. L.

      2016-08-01

      Since their discovery, the Quintuplet proper members (QPMs) have been somewhat mysterious in nature. Originally dubbed the “cocoon stars” due to their cool featureless spectra, high-resolution near-infrared imaging observations have shown that at least two of the objects exhibit “pinwheel” nebulae consistent with binary systems with a carbon-rich Wolf–Rayet star and O/B companion. In this paper, we present 19.7, 25.2, 31.5, and 37.1 μm observations of the QPMs (with an angular resolution of 3.2″–3.8″) taken with the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST) in conjunction with high-resolution (∼0.1″–0.2″) images at 8.8 and 11.7 μm from the Thermal-Region Camera Spectrograph (TReCS). DUSTY models of the thermal dust emission of two of the four detected QPMs, Q2 and Q3, are fitted by radial density profiles that are consistent with constant mass-loss rates ({ρ }d\\propto {r}-2). For the two remaining sources, Q1 and Q9, extended structures (∼1″) are detected around these objects in high-resolution imaging data. Based on the fitted dust masses, Q9 has an unusually large dust reservoir ({M}{{d}}={1.3}-0.4+0.8× {10}-3{M}ȯ ) compared to typical dusty Wolf–Rayet stars, which suggests that it may have recently undergone an episode of enhanced mass loss.

    2. Detection of faint BLR components in the starburst/Seyfert galaxy NGC 6221 and measure of the central BH mass

      NASA Astrophysics Data System (ADS)

      La Franca, Fabio; Onori, Francesca; Ricci, Federica; Bianchi, Stefano; Marconi, Alessandro; Sani, Eleonora; Vignali, Cristian

      2016-04-01

      In the last decade, using single epoch virial based techniques in the optical band, it has been possible to measure the central black hole mass on large type 1 Active Galactive Nuclei (AGN) samples. However these measurements use the width of the broad line region as a proxy of the virial velocities and are therefore difficult to be carried out on those obscured (type 2) or low luminosity AGN where the nuclear component does not dominate in the optical. Here we present the optical and near infrared spectrum of the starburst/Seyfert galaxy NGC 6221, observed with X-shooter/VLT. Previous observations of NGC 6221 in the X-ray band shows an absorbed (N_H=8.5 +/- 0.4 x 10^21 cm^-2) spectrum typical of a type 2 AGN with luminosity log(L_14-195/ erg s^-1) = 42.05, while in the optical band its spectrum is typical of a reddened (A_V=3) starburst. Our deep X-shooter/VLT observations have allowed us to detect faint broad emission in the H_alpha, HeI and Pa_beta lines (FWHM=1400-2300 km s^-1) confirming previous studies indicating that NGC 6221 is a reddened starbust galaxy which hosts an AGN. We use the measure of the broad components to provide a first estimate of its central black hole mass (M_BH = 10^6.6+/-0.3 Msol, lambda_Edd=0.01-0.03), obtained using recently calibrated virial relations suitable for moderately obscured (N_H<10^24 cm^-2) AGN.

    3. Optical/infrared views of the distant universe with ground-based telescopes

      NASA Astrophysics Data System (ADS)

      Gallagher, J. S.; Tolstoy, E.

      1997-05-01

      Ground-based optical/IR observatories offer access to the rest frame ultraviolet and visible spectral regions of objects with high redshifts. Current observations of high redshift objects with natural seeing of 0.5-1 arcsec include optical/IR photometry and a variety of spectroscopic measurements. These take advantage of the large apertures and efficient instruments of ground-based observatories to obtain high spectral resolution and to reach low surface brightnesses, which is required to overcome cosmological effects. The success of natural guide star adaptive optics systems suggests that observations could become routine with image diameters <=0.25 arcsec (and often approaching 0.1 arcsec) over modest fields of view in the IJHK bands. The combination of adaptive optics on 8-10-m class telescopes, versatile arrays of powerful instruments (including multi-slit or integral field unit spectrographs), and airglow suppression schemes will support deeper and more intensive infrared investigations of faint galaxies, and will allow us to take advantage of increased brightness in strong emission lines. This work should lead to a better understanding of selection effects at high redshift, as well as the identification and measurement of internal properties for typical galaxies at early epochs.

    4. High-Resolution Infrared Imaging of FSC 10214+4724: Evidence for Gravitational Lensing

      NASA Astrophysics Data System (ADS)

      Graham, James R.; Liu, Michael C.

      1995-08-01

      We present near-infrared observations of the ultraluminous high-redshift (z = 2.286) IRAS source FSC 10214+4724 obtained in 0."4 seeing at the W. M. Keck telescope. These observations show that FSC 10214+4724 consists of a highly symmetric circular arc centered on a second weaker source. The arc has an angular extent of about 140 deg and is probably unresolved in the transverse direction. This morphology constitutes compelling prima facie evidence for a gravitationally lensed system. Our images also contain evidence for the faint counterimage predicted by the lens hypothesis. The morphology of FSC 10214+4724 can be explained in terms of a gravitationally lensed background source if the object at the center of curvature of the arc is an L* galaxy at z ~ 0.7. If FSC 10214+4724 is lensed, then there is significant magnification and its luminosity has been overestimated by a large factor. Our results suggest that FSC 10214+4724 is not a uniquely luminous object but ranks among the most powerful quasars and ultraluminous IRAS galaxies.

    5. Infrared telescope

      NASA Technical Reports Server (NTRS)

      Karr, G. R.; Hendricks, J. B.

      1985-01-01

      The development of the Infrared Telescope for Spacelab 2 is discussed. The design, development, and testing required to interface a stationary superfluid helium dewar with a scanning cryostate capable of operating in the zero-g environment in the space shuttle bay is described.

    6. Infrared Thermometers

      ERIC Educational Resources Information Center

      Schaefers, John

      2006-01-01

      An infrared (IR) thermometer lab offers the opportunity to give science students a chance to measure surface temperatures, utilizing off-the-shelf technology. Potential areas of study include astronomy (exoplanets), electromagnetic spectrum, chemistry, evaporation rates, anatomy, crystal formation, and water or liquids. This article presents one…

    7. Infrared spectroscopy

      NASA Astrophysics Data System (ADS)

      Lopez, B. A.

      1984-11-01

      Infrared spectroscopic analysis is reviewed. Applications to chemical analysis of preimpregnated carbon fiber materials, including polystyrene spectra, epoxy resin analysis, mineral loads analysis, determination of epoxy groups and identification of spurious organic materials are discussed. The advantages of the method for quality control are pointed out.

    8. Far-infrared polarimetry

      NASA Technical Reports Server (NTRS)

      Hildebrand, Roger H.; Dotson, Jesse L.; Dowell, C. Darren; Platt, S. R.; Schleuning, David; Davidson, J. A.; Novak, Giles

      1995-01-01

      Airborne observations with the The University of Chicago polarimeter, Stokes (Platt et al. 1991), have produced maps of far infrared polarization over large areas in molecular clouds. Subsequent papers will discuss the implications of the results concerning the magnetic fields of individual objects. Our purpose here is to show a broad sample of the results and to point out certain general characteristics of the polarized emission.

    9. The SCUBA HAlf Degree Extragalactic Survey (SHADES) - V. Submillimetre properties of near-infrared-selected galaxies in the Subaru/XMM -Newton deep field

      NASA Astrophysics Data System (ADS)

      Takagi, T.; Mortier, A. M. J.; Shimasaku, K.; Coppin, K.; Pope, A.; Ivison, R. J.; Hanami, H.; Serjeant, S.; Clements, D. L.; Priddey, R. S.; Dunlop, J. S.; Takata, T.; Aretxaga, I.; Chapman, S. C.; Eales, S. A.; Farrah, D.; Granato, G. L.; Halpern, M.; Hughes, D. H.; van Kampen, E.; Scott, D.; Sekiguchi, K.; Smail, I.; Vaccari, M.

      2007-11-01

      We have studied the submillimetre (submm) properties of the following classes of near-infrared-selected (NIR-selected) massive galaxies at high redshifts: BzK-selected star-forming galaxies (BzKs); distant red galaxies (DRGs); and extremely red objects (EROs). We used the SCUBA HAlf Degree Extragalactic Survey (SHADES), the largest uniform submm survey to date. Partial overlap of SIRIUS/NIR images and SHADES in Subaru/XMM-Newton deep field has allowed us to identify four submm-bright NIR-selected galaxies, which are detected in the mid-IR, 24μ m, and the radio, 1.4GHz. We find that all of our submm-bright NIR-selected galaxies satisfy the BzK selection criteria, i.e. BzK ≡ (z - K)AB - (B - z)AB >= -0.2, except for one galaxy whose B - z and z - K colours are however close to the BzK colour boundary. Two of the submm-bright NIR-selected galaxies satisfy all of the selection criteria we considered, i.e. they belong to the BzK-DRG-ERO overlapping population, or `extremely red' BzKs. Although these extremely red BzKs are rare (0.25 arcmin-2), up to 20 per cent of this population could be submm galaxies. This fraction is significantly higher than that found for other galaxy populations studied here. Via a stacking analysis, we have detected the 850-μ m flux of submm-faint BzKs and EROs in our SCUBA maps. While the contribution of z ~ 2 BzKs to the submm background is about 10-15 per cent and similar to that from EROs typically at z ~ 1, BzKs have a higher fraction (~30 per cent) of submm flux in resolved sources compared with EROs and submm sources as a whole. From the spectral energy distribution (SED) fitting analysis for both submm-bright and submm-faint BzKs, we found no clear signature that submm-bright BzKs are experiencing a specifically luminous evolutionary phase, compared with submm-faint BzKs. An alternative explanation might be that submm-bright BzKs are more massive than submm-faint ones.

    10. COOL WHITE DWARFS FOUND IN THE UKIRT INFRARED DEEP SKY SURVEY

      SciTech Connect

      Leggett, S. K.; Nitta, A.; Lodieu, N.

      2011-07-01

      We present the results of a search for cool white dwarfs in the United Kingdom InfraRed Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The UKIDSS LAS photometry was paired with the Sloan Digital Sky Survey to identify cool hydrogen-rich white dwarf candidates by their neutral optical colors and blue near-infrared colors, as well as faint reduced proper motion magnitudes. Optical spectroscopy was obtained at Gemini Observatory and showed the majority of the candidates to be newly identified cool degenerates, with a small number of G- to K-type (sub)dwarf contaminants. Our initial search of 280 deg{sup 2} of sky resulted in seven new white dwarfs with effective temperature T{sub eff} {approx} 6000 K. The current follow-up of 1400 deg{sup 2} of sky has produced 13 new white dwarfs. Model fits to the photometry show that seven of the newly identified white dwarfs have 4120 K {<=}T{sub eff} {<=} 4480 K, and cooling ages between 7.3 Gyr and 8.7 Gyr; they have 40 km s{sup -1} {<=} v{sub tan} {<=} 85 km s{sup -1} and are likely to be thick disk 10-11 Gyr-old objects. The other half of the sample has 4610 K {<=}T{sub eff} {<=} 5260 K, cooling ages between 4.3 Gyr and 6.9 Gyr, and 60 km s{sup -1} {<=} v{sub tan} {<=} 100 km s{sup -1}. These are either thin disk remnants with unusually high velocities, or lower-mass remnants of thick disk or halo late-F or G stars.

    11. Revealing the Galactic Center in the Far-Infrared with SOFIA/FORCAST

      NASA Astrophysics Data System (ADS)

      Lau, Ryan M.; Herter, Terry; Morris, Mark; Li, Zhiyuan; Becklin, Eric; Adams, Joseph; Hankins, Matthew

      2015-08-01

      We present a summary of far-infrared imaging observations of the inner 40 pc of the Galactic center addressing the dense, dusty torus around Sgr A*, massive star formation, and dust production around massive stars and in the Sgr A East supernova remnant. Observations of warm dust emission were performed using the Faint Object Infrared Camera for the SOFIA Telescope (FORCAST). The Circumnuclear Ring (CNR) surrounding and heated by central cluster in the vicinity of Sgr A* shows no internal active star formation but does exhibit significant density “clumps,” a surprising result because tidal shearing should act quickly to smear out structure. G-0.02-0.07, a complex consisting of three compact HII regions and one ultracompact HII region, is site of the most recent confirmed star formation within ~10 pc of the Galactic center. Our observations reveal the dust morphologies and SEDs of the regions to constrain the composition and gas-to-dust mass ratios of the emitting dust and identify heating sources candidates from archival near-IR images. FORCAST observations Luminous Blue Variables (LBVs) located in and near the Quintuplet Cluster reveal the asymmetric, compressed shell of hot dust surrounding the Pistol Star and provide the first detection of the thermal emission from the symmetric, hot dust envelope surrounding G0.120-0.048. These two LBV’s have nebulae with similar quantities of dust (~0.02 M⊙) but exhibit contrasting appearances due to the external influence of their different environments. Finally, the far-infrared observations indicate the presence of ~0.02 M⊙ of warm (~100 K) dust in the hot interior of the ~10,000 yr-old SgrA East supernova remnant indicating the dust has survived the passage of the reverse shock. The results suggest that supernovae may indeed be the dominant dust production mechanism in the dense environment of early Universe galaxies.

    12. Large MEMS-based programmable reflective slit mask for multi-object spectroscopy fabricated using multiple wafer-level bonding

      NASA Astrophysics Data System (ADS)

      Canonica, Michael; Zamkotsian, Frederic; Lanzoni, Patrick; Noell, Wilfried; de Rooij, Nico

      2012-03-01

      Multi-object spectroscopy (MOS) allows measuring infrared spectra of faint astronomical objects that provides information on the evolution of the Universe. MOS requires a slit mask for object selection at the focal plane of the telescope. We are developing MEMS-based programmable reflective slit masks composed of 2048 individually addressable micromirrors. Each micromirror measures 100 × 200 μm2 and is electrostatically tilted by a precise angle of at least 20°. The main requirements for these arrays are precise and uniform tilt angle over the whole device, uniformity of the mirror electromechanical behavior, a flat mirror deformation and individual addressing capability of each mirror. This capability of our array is achieved using a line-column algorithm based on an optimized tilt angle/voltage hysteresis of the electrostatic actuator. Micromirror arrays composed of 2048 micromirrors (32 × 64) and modeled for individual addressing were fabricated using fusion and eutectic wafer-level bonding. These micromirrors without coating demonstrated a peak-to-valley deformation less than 8 nm and a tilt angle of 24° for an actuation voltage of 130 V. A first experiment of the linecolumn algorithm was demonstrated by actuating individually 2 × 2 micromirrors. In order, to avoid spoiling of the optical source by the thermal emission of the instrument, the micromirror array has to work in a cryogenic environment. Therefore, these devices were characterized in a cryogenic environment at -111°C and several lines of micromirrors were tilted successfully under these conditions.

    13. Solutions to the faint young Sun paradox simulated by a general circulation model

      NASA Astrophysics Data System (ADS)

      Wolf, Eric Theodore

      The faint young Sun paradox has dominated our thinking regarding early climate. Geological evidence abounds for warm, possibly hot, seawater temperatures and the proliferation of early life during the Archean period of Earth's history (3.8-2.5 Ga). However the standard solar model indicates that the Sun was only 75 to 82 percent as bright as today, implying an apparent contradiction between warm surface temperatures and weak solar irradiance. Geological evidence also places constraints on the amount of atmospheric carbon dioxide present early in Earth's history. Over the past four decades there has been much debate amongst geological, planetary, and climate science communities regarding how to properly resolve the issue of the faint young Sun. Up until very recently, 1-dimensional radiative convective models were the standard tool for deep paleoclimate modeling studies. These studies have notably lacked the ability to treat clouds, surface ice, and meridional energy transport. However, advancements in computing technology now allow us to tackle the faint young Sun paradox using a three-dimensional climate model. Here we use a modified version of the Community Atmosphere Model version 3 from the National Center for Atmospheric Research to study early climate. We find that resolving the faint young Sun paradox becomes less problematic when viewing a full representation of the climate system. Modest amounts of carbon dioxide and methane can provide adequate warming for the Archean within given constraints. Cooler climates with large ice caps but temperate tropical regions can be supported with even less carbon dioxide. The incorporation of systematic climate system differences expected during the Archean, such as fewer cloud condensation nuclei, reduced land albedos, and increased atmospheric nitrogen, can provide additional non-greenhouse means of warming the early Earth. A warm Archean no longer appears at odds with a faint young Sun. Here, we will also discuss the

    14. Parallel object-oriented data mining system

      DOEpatents

      Kamath, Chandrika; Cantu-Paz, Erick

      2004-01-06

      A data mining system uncovers patterns, associations, anomalies and other statistically significant structures in data. Data files are read and displayed. Objects in the data files are identified. Relevant features for the objects are extracted. Patterns among the objects are recognized based upon the features. Data from the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) sky survey was used to search for bent doubles. This test was conducted on data from the Very Large Array in New Mexico which seeks to locate a special type of quasar (radio-emitting stellar object) called bent doubles. The FIRST survey has generated more than 32,000 images of the sky to date. Each image is 7.1 megabytes, yielding more than 100 gigabytes of image data in the entire data set.

    15. Hubble Provides Infrared View of Jupiter's Moon, Ring, and Clouds

      NASA Technical Reports Server (NTRS)

      1997-01-01

      Probing Jupiter's atmosphere for the first time, the Hubble Space Telescope's new Near Infrared Camera and Multi-Object Spectrometer (NICMOS) provides a sharp glimpse of the planet's ring, moon, and high-altitude clouds.

      The presence of methane in Jupiter's hydrogen- and helium-rich atmosphere has allowed NICMOS to plumb Jupiter's atmosphere, revealing bands of high-altitude clouds. Visible light observations cannot provide a clear view of these high clouds because the underlying clouds reflect so much visible light that the higher level clouds are indistinguishable from the lower layer. The methane gas between the main cloud deck and the high clouds absorbs the reflected infrared light, allowing those clouds that are above most of the atmosphere to appear bright. Scientists will use NICMOS to study the high altitude portion of Jupiter's atmosphere to study clouds at lower levels. They will then analyze those images along with visible light information to compile a clearer picture of the planet's weather. Clouds at different levels tell unique stories. On Earth, for example, ice crystal (cirrus) clouds are found at high altitudes while water (cumulus) clouds are at lower levels.

      Besides showing details of the planet's high-altitude clouds, NICMOS also provides a clear view of the ring and the moon, Metis. Jupiter's ring plane, seen nearly edge-on, is visible as a faint line on the upper right portion of the NICMOS image. Metis can be seen in the ring plane (the bright circle on the ring's outer edge). The moon is 25 miles wide and about 80,000 miles from Jupiter.

      Because of the near-infrared camera's narrow field of view, this image is a mosaic constructed from three individual images taken Sept. 17, 1997. The color intensity was adjusted to accentuate the high-altitude clouds. The dark circle on the disk of Jupiter (center of image) is an artifact of the imaging system.

      This image and other images and data received from the Hubble Space Telescope are

    16. Improving the Visible and Infrared Contrast Ratio of Microshutter Arrays

      NASA Technical Reports Server (NTRS)

      Jhabvala, Murzy; Li, Mary; Moseley, Harvey; Franz, Dave; Yun, Zheng; Kutyrev, Alexander

      2009-01-01

      Three device improvements have been developed that dramatically enhance the contrast ratio of microshutters. The goal of a microshutter is to allow as much light through as possible when the shutters are in the open configuration, and preventing any light from passing through when they are in the closed position. The ratio of the transmitted light that is blocked is defined here as the contrast ratio. Three major components contribute to the improved performance of these microshutters: 1. The precise implementation of light shields, which protect the gap around the shutters so no light can leak through. It has been ascertained that without the light shield there would be a gap on the order of 1 percent of the shutter area, limiting the contrast to a maximum of 100. 2. The precise coating of the interior wall of each microshutter was improved with an insulator and metal using an angle deposition technique. The coating prevents any infrared light that finds an entrance on the surface of the microshutter cell from being emitted from a sidewall. Since silicon is in effect transparent to any light with a wavelength longer than .1 micrometer, these coatings are essential to blocking any stray signals when the shutters are closed. 3. A thin film of molybdenum nitride (MoN) was integrated onto the surface of the microshutter blade. This film provides the majority of light blockage over the microshutter and also ensures that the shutter can be operated over a wide temperature range by maintaining its flatness. These improvements were motivated by the requirements dictated by the James Webb Space Telescope NIRSpec instrument. The science goals of the NIRSpec require observing some of the very faintest objects in a given field of view that also may contain some very bright objects. To observe the faint objects, the light from the bright objects - which could be thousands of times brighter - must be completely blocked. If a closed microshutter is even slightly transmissive, a

    17. Method for imaging a concealed object

      DOEpatents

      Davidson, James R [Idaho Falls, ID; Partin, Judy K [Idaho Falls, ID; Sawyers, Robert J [Idaho Falls, ID

      2007-07-03

      A method for imaging a concealed object is described and which includes a step of providing a heat radiating body, and wherein an object to be detected is concealed on the heat radiating body; imaging the heat radiating body to provide a visibly discernible infrared image of the heat radiating body; and determining if the visibly discernible infrared image of the heat radiating body is masked by the presence of the concealed object.

    18. Trusted Objects

      SciTech Connect

      CAMPBELL,PHILIP L.; PIERSON,LYNDON G.; WITZKE,EDWARD L.

      1999-10-27

      In the world of computers a trusted object is a collection of possibly-sensitive data and programs that can be allowed to reside and execute on a computer, even on an adversary's machine. Beyond the scope of one computer we believe that network-based agents in high-consequence and highly reliable applications will depend on this approach, and that the basis for such objects is what we call ''faithful execution.''

    19. WFC3IR Imaging of UV-Faint z=6 Quasars: Star-Forming Host Galaxies of AGN in the Early Universe

      NASA Astrophysics Data System (ADS)

      Mechtley, Matthew

      2012-10-01

      We propose to study the star-forming host galaxies of AGN at z 6 with WFC3/IR in F125W and F160W. Recently, far-infrared {FIR} continuum has been detected in five UV-faint {rest-frame m_1450>20.2} quasars at z 6, suggesting that they have star formation rates {SFRs} of 1000 MSun/yr, comparable to UV-bright z 6 quasars. Such SFRs imply a significant young, UV-bright stellar population. These host galaxies have yet to be seen in starlight, however, since light from the AGN still dominates the rest-frame UV emission.We successfully subtracted the point source in the UV-bright {m_1450=19.03} quasar J1148+5251 down to mu_J>24.4, mu_H>24.9 mag arcsec^-2, giving upper limits of m_1680>22.5, m_2160>23.0 mag for the host galaxy {Program 12332, PI Windhorst}. Uncertainties in the PSF model remain the dominant source of residuals. Since these uncertainties scale with brightness, low-contrast quasars with UV-faint point sources and UV-bright hosts are the best targets for this method.Using the observing and subtraction methods we developed, we propose to observe all 5 FIR-detected, UV-faint z 6 quasars with WFC3/IR in F125W and F160W. We request 5 orbits per quasar, for a total of 25 orbits. This program is beyond the capability of ground-based AO facilities, due to depth and PSF stability required. Observations of these host galaxies are critical to determine:{a} The existence of a luminous stellar component{b} Luminosity and color profiles, to constrain star formation histories{c} Morphologies and sizes, to look for mergers and hierarchical formation processes{d} Stellar mass, to understand formation and co-evolution of SMBHs and galaxy bulges

    20. Revealing the Nature of Faint X-Ray Sources in the Giant Star-Forming Region NGC 3603

      NASA Astrophysics Data System (ADS)

      Poteet, C.; Marchenko, S.; Corcoran, M.; Andersen, M.

      2004-12-01

      NGC 3603, an open cluster embedded in the largest Galactic H II region, contains some of the most luminous, massive stars known in the Galaxy. It may serve as a good analog of star-forming regions in external starburst galaxies. The recent deep (50 Ksec) {Chandra} imaging of NGC 3603 revealed that its X-Ray emission is dominated by the bright Wolf-Rayet and O stars in the cluster core. However, there are hundreds of extremely weak point-like X-ray sources surrounding the central region. They tend to concentrate towards the cluster's center, suggestive of real cluster membership. Studying this population, we find that absolute majority of the weak sources does not belong to the lists of known OB and WR cluster members. Practically all the 263 weak X-ray sources have faint near-IR counterparts in the deep J,H,K images obtained by the ISAAC instrument on the VLT. Around 50% of the X-ray sources can be considered as visual binaries, an additional ˜ 20% as multiple systems (up to six stars in a r=1.5" ˜ 3σ circle). The composite spectrum of these sources is quite hard (kT ˜ 6 keV) and fairly absorbed (NH ˜ 1022). There is no obvious line emission, in particular, no strong Fe XXV line, so presently we cannot distinguish between thermal and non-thermal emission. The JHK colour-colour and colour-magnitude diagrams of the X-ray selected sources indicate that the X-ray data are very efficient in discriminating between field stars and cluster members. The X-ray sources have similar near-infrared properties as the whole near-infrared sample of the known cluster members. Hence, the discovered population of weak X-ray sources provide an effective means to obtain a "clean" sample of pre-main sequence stars down to 1 M⊙ assuming the cluster is 1 Myr old.