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Sample records for galaxies ii near-infrared

  1. The Near-Infrared Ca II Triplet-σ Relation for Bulges of Spiral Galaxies

    NASA Astrophysics Data System (ADS)

    Falcón-Barroso, Jesús; Peletier, Reynier F.; Vazdekis, Alexandre; Balcells, Marc

    2003-05-01

    We present measurements of the near-infrared Ca II triplet (CaT, CaT*), Paschen (PaT), and magnesium (Mg I) indices for a well-studied sample of 19 bulges of early to intermediate spiral galaxies. We find that both the CaT* and CaT indices decrease with central velocity dispersion σ with small scatter. This dependence is similar to that recently found by Cenarro for elliptical galaxies, implying a uniform CaT*-σ relation that applies to galaxies from ellipticals to intermediate-type spirals. The decrease of CaT and CaT* with σ contrasts with the well-known increase of another α-element index, Mg2, with σ. We discuss the role of Ca underabundance ([Ca/Fe]<0) and initial mass function variations in the onset of the observed relations.

  2. A spectral atlas of H II galaxies in the near-infrared

    NASA Astrophysics Data System (ADS)

    Martins, Lucimara P.; Rodríguez-Ardila, Alberto; Diniz, Suzi; Gruenwald, Ruth; de Souza, Ronaldo

    2013-05-01

    Recent models show that thermally pulsing asymptotic giant branches (TP-AGB) stars should dominate the near-infrared (NIR) spectra of populations 0.3-2 Gyr old, leaving unique signatures that can be used to detect young/intermediate stellar population in galaxies. However, no homogeneous data base of star-forming galaxies is available in the NIR to fully explore and apply these results. With this in mind, we study the NIR spectra of a sample of 23 H II and starburst galaxies, aimed at characterizing the most prominent spectral features (emission and absorption) and continuum shape in the 0.8-2.4 μm region of these objects. Five normal galaxies are also observed as a control sample. Spectral indices are derived for the relevant absorption lines/bands and a comparison with optical indices of the same sample of galaxies available in the literature is made. We found no correlation between the optical and the NIR indices. This is probably due to the differences in aperture between these two sets of data. That result is further supported by the absence or weakness of emission lines in the NIR for a subsample of galaxies, while in the optical the emission lines are strong and clear, which means that the ionization source in many of these galaxies is not nuclear, but circumnuclear or located in hotspots outside the nucleus. We detected important signatures predicted for a stellar population dominated by the TP-AGB, like CN 1.1 μm and CO 2.3 μm. In at least one galaxy (NGC 4102), the CN band at 1.4 μm was detected for the first time. We also detect TiO and ZrO bands in the region 0.8-1 μm that have never been reported before in extragalactic sources. The shape of the continuum emission is found to be strongly correlated to the presence/lack of emission lines. An observational template for the star-forming galaxies is derived to be used as a benchmark of stellar population(s) in starburst galaxies against which to compare NIR spectroscopy of different types of galaxies

  3. A NEAR-INFRARED TEMPLATE DERIVED FROM I Zw 1 FOR THE Fe II EMISSION IN ACTIVE GALAXIES

    SciTech Connect

    Garcia-Rissmann, A.; Rodriguez-Ardila, A.; Sigut, T. A. A.; Pradhan, A. K.

    2012-05-20

    In active galactic nucleus spectra, a series of Fe II multiplets form a pseudo-continuum that extends from the ultraviolet to the near-infrared (NIR). This emission is believed to originate in the broad-line region, and it has been known for a long time that pure photoionization fails to reproduce it in the most extreme cases, as does the collisional excitation alone. The most recent models by Sigut and Pradhan include details of the Fe II ion microphysics and cover a wide range in the ionization parameter log U{sub ion} = (- 3.0 {yields} -1.3) and density log n{sub H} = (9.6 {yields} 12.6). With the aid of such models and a spectral synthesis approach, we studied for the first time in detail the NIR emission of I Zw 1. The main goals were to confirm the role played by Ly{alpha} fluorescence mechanisms in the production of the Fe II spectrum and to construct the first semi-empirical NIR Fe II template that best represents this emission, consequently allowing its clean subtraction in other sources. A good overall match between the observed Fe II+Mg II features with those predicted by the best-fitted model was obtained, corroborating the Ly{alpha} fluorescence as a key process to understand the Fe II spectrum. The best model was fine-tuned by applying a deconvolution method to the observed Fe II+Mg II spectrum. This derived semi-empirical template was then fitted to the spectrum of Ark 564, showing that it nicely reproduced its observed Fe II+Mg II emission. Our work extends the current set of available Fe II templates into the NIR region.

  4. A Near-infrared Template Derived from I Zw 1 for the Fe II Emission in Active Galaxies

    NASA Astrophysics Data System (ADS)

    Garcia-Rissmann, A.; Rodríguez-Ardila, A.; Sigut, T. A. A.; Pradhan, A. K.

    2012-05-01

    In active galactic nucleus spectra, a series of Fe II multiplets form a pseudo-continuum that extends from the ultraviolet to the near-infrared (NIR). This emission is believed to originate in the broad-line region, and it has been known for a long time that pure photoionization fails to reproduce it in the most extreme cases, as does the collisional excitation alone. The most recent models by Sigut & Pradhan include details of the Fe II ion microphysics and cover a wide range in the ionization parameter log U ion = (- 3.0 → -1.3) and density log n H = (9.6 → 12.6). With the aid of such models and a spectral synthesis approach, we studied for the first time in detail the NIR emission of I Zw 1. The main goals were to confirm the role played by Lyα fluorescence mechanisms in the production of the Fe II spectrum and to construct the first semi-empirical NIR Fe II template that best represents this emission, consequently allowing its clean subtraction in other sources. A good overall match between the observed Fe II+Mg II features with those predicted by the best-fitted model was obtained, corroborating the Lyα fluorescence as a key process to understand the Fe II spectrum. The best model was fine-tuned by applying a deconvolution method to the observed Fe II+Mg II spectrum. This derived semi-empirical template was then fitted to the spectrum of Ark 564, showing that it nicely reproduced its observed Fe II+Mg II emission. Our work extends the current set of available Fe II templates into the NIR region.

  5. Hubble Space Telescope Near-infrared Snapshot Survey of 3CR Radio Source Counterparts. II. An Atlas and Inventory of the Host Galaxies, Mergers, and Companions

    NASA Astrophysics Data System (ADS)

    Floyd, David J. E.; Axon, David; Baum, Stefi; Capetti, Alessandro; Chiaberge, Marco; Macchetto, Duccio; Madrid, Juan; Miley, George; O'Dea, Christopher P.; Perlman, Eric; Quillen, Alice; Sparks, William; Tremblay, Grant

    2008-07-01

    We present the second part of an H-band (1.6 μm) "atlas" of z < 0.3 3CR radio galaxies, using the Hubble Space Telescope Near Infrared Camera and Multi-Object Spectrometer (HST NICMOS2). We present new imaging for 21 recently acquired sources and host galaxy modeling for the full sample of 101 (including 11 archival)—an 87% completion rate. Two different modeling techniques are applied, following those adopted by the galaxy morphology and the quasar host galaxy communities. Results are compared and found to be in excellent agreement, although the former breaks down in the case of sources with strong active galactic nuclei (AGNs). Companion sources are tabulated, and the presence of mergers, tidal features, dust disks, and jets are cataloged. The tables form a catalog for those interested in the structural and morphological dust-free host galaxy properties of the 3CR sample, and for comparison with morphological studies of quiescent galaxies and quasar host galaxies. Host galaxy masses are estimated and found to typically lie at around 2 × 1011 M⊙. In general, the population is found to be consistent with the local population of quiescent elliptical galaxies, but with a longer tail to low Sérsic index, mainly consisting of low-redshift (z < 0.1) and low-radio-power (FR I) sources. A few unusually disky FR II host galaxies are picked out for further discussion. Nearby external sources are identified in the majority of our images, many of which we argue are likely to be companion galaxies or merger remnants. The reduced NICMOS data are now publicly available from our Web site. Based on observations 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. (AURA), under NASA contract NAS5-26555.

  6. Near-Infrared Imaging of Six Metal-rich Quasar Absorber Galaxy Fields

    NASA Astrophysics Data System (ADS)

    Straka, Lorrie A.; Kulkarni, Varsha P.; York, Donald G.

    2011-06-01

    Absorption lines in quasar spectra allow us to locate and study intervening galaxies. In order to obtain a clearer picture of these absorber galaxies, we have used the Near-Infrared Camera Fabry-Perot System at Apache Point Observatory to obtain near-infrared broadband images in one or more filters (J and Ks ) of six quasar fields containing metal-rich low-z damped or sub-damped Lyα systems. These data allow us to search for the galaxies and constrain their luminosities. Candidate absorber galaxies are detected at 2farcs01-7farcs38 separation from the quasar in three out of six fields in the J and Ks bands at >3σ level with luminosities ranging from log(L/L sun) = 10.44-10.36 in the J band (for E-Sc type galaxies) and log(L/L sun) = 11.59-10.03 in the Ks band for our detections. We place limits on the remaining fields with no detections of log(L/L sun) <10.83-9.75 for the J band and log(L/L sun) <10.43-10.05 for the Ks band. We are also able to utilize Sloan Digital Sky Survey spectra for each field to calculate optical fluxes and limits as well as limits on star formation rate via [O II]λ3727 emission in spectra. Our data, combined with other recent imaging results for metal-rich absorbers, suggest a possible positive correlation between absorber metallicity and galaxy luminosity, although the samples are still small.

  7. NEAR-INFRARED IMAGING OF SIX METAL-RICH QUASAR ABSORBER GALAXY FIELDS

    SciTech Connect

    Straka, Lorrie A.; Kulkarni, Varsha P.; York, Donald G.

    2011-06-15

    Absorption lines in quasar spectra allow us to locate and study intervening galaxies. In order to obtain a clearer picture of these absorber galaxies, we have used the Near-Infrared Camera Fabry-Perot System at Apache Point Observatory to obtain near-infrared broadband images in one or more filters (J and K{sub s} ) of six quasar fields containing metal-rich low-z damped or sub-damped Ly{alpha} systems. These data allow us to search for the galaxies and constrain their luminosities. Candidate absorber galaxies are detected at 2.''01-7.''38 separation from the quasar in three out of six fields in the J and K{sub s} bands at >3{sigma} level with luminosities ranging from log(L/L{sub sun}) = 10.44-10.36 in the J band (for E-Sc type galaxies) and log(L/L{sub sun}) = 11.59-10.03 in the K{sub s} band for our detections. We place limits on the remaining fields with no detections of log(L/L{sub sun}) <10.83-9.75 for the J band and log(L/L{sub sun}) <10.43-10.05 for the K{sub s} band. We are also able to utilize Sloan Digital Sky Survey spectra for each field to calculate optical fluxes and limits as well as limits on star formation rate via [O II]{lambda}3727 emission in spectra. Our data, combined with other recent imaging results for metal-rich absorbers, suggest a possible positive correlation between absorber metallicity and galaxy luminosity, although the samples are still small.

  8. Near-infrared line-strengths in elliptical galaxies: evidence for initial mass function variations?

    NASA Astrophysics Data System (ADS)

    Cenarro, A. J.; Gorgas, J.; Vazdekis, A.; Cardiel, N.; Peletier, R. F.

    2003-02-01

    We present new relations between recently defined line-strength indices in the near-infrared (CaT*, CaT, PaT, MgI and sTiO) and central velocity dispersion (σ0) for a sample of 35 early-type galaxies, showing evidence for significant anti-correlations between CaII triplet indices (CaT* and CaT) and log σ0. These relations are interpreted in the light of our recent evolutionary synthesis model predictions, suggesting the existence of important Ca underabundances with respect to Fe and/or an increase of the dwarf to giant stars ratio along the mass sequence of elliptical galaxies.

  9. Near-infrared photometry and stellar populations in dwarf elliptical and irregular galaxies

    NASA Technical Reports Server (NTRS)

    Thuan, T. X.

    1985-01-01

    Studies of three different types of dwarf galaxies have been conducted, taking into account low surface brightness (LSB) dwarf irregular (dI) galaxies, dwarf elliptical (dE) galaxies, and blue compact dwarf galaxies (BCDGs). Near-infrared observations for a large sample of BCDGs have been reported by Thuan (1983). The present paper is concerned with complementary near-infrared observations for a large sample of LSB dI and dE galaxies, and, in addition, with a few additional BCDG observations. In a discussion of dwarf elliptical galaxies, attention is given to an infrared color-color diagram, optical-infrared colors and burst ages, and the UVK color plane. Low surface brightness dwarf irregular galaxies and blue compact dwarf galaxies are considered along with the possible evolutionary scenarios which may link LSB dIs, BCDGs, and dEs.

  10. THE COSMIC NEAR-INFRARED BACKGROUND. II. FLUCTUATIONS

    SciTech Connect

    Fernandez, Elizabeth R.; Komatsu, Eiichiro; Shapiro, Paul R.; Iliev, Ilian T.

    2010-02-20

    The near-infrared background (NIRB) is one of a few methods that can be used to observe the redshifted light from early stars at a redshift of 6 and above, and thus it is imperative to understand the significance of any detection or nondetection of the NIRB. Fluctuations of the NIRB can provide information on the first structures, such as halos and their surrounding ionized regions in the intergalactic medium (IGM). We combine, for the first time, N-body simulations, radiative transfer code, and analytic calculations of luminosity of early structures to predict the angular power spectrum (C{sub l} ) of fluctuations in the NIRB. We study in detail the effects of various assumptions about the stellar mass, the initial mass spectrum of stars, the metallicity, the star formation efficiency (f{sub *}), the escape fraction of ionizing photons (f{sub esc}), and the star formation timescale (t{sub SF}), on the amplitude as well as the shape of C{sub l} . The power spectrum of NIRB fluctuations is maximized when f{sub *} is the largest (as C{sub l} {proportional_to} f {sup 2}{sub *}) and f{sub esc} is the smallest (as more nebular emission is produced within halos). A significant uncertainty in the predicted amplitude of C{sub l} exists due to our lack of knowledge of t{sub SF} of these early populations of galaxies, which is equivalent to our lack of knowledge of the mass-to-light ratio of these sources. We do not see a turnover in the NIRB angular power spectrum of the halo contribution, which was claimed to exist in the literature, and explain this as the effect of high levels of nonlinear bias that was ignored in the previous calculations. This is partly due to our choice of the minimum mass of halos contributing to NIRB ({approx}2 x 10{sup 9} M{sub sun}), and a smaller minimum mass, which has a smaller nonlinear bias, may still exhibit a turnover. Therefore, our results suggest that both the amplitude and shape of the NIRB power spectrum provide important information

  11. The Nuclear Near-Infrared Spectral Properties of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Mason, R. E.; Rodríguez-Ardila, A.; Martins, L.; Riffel, R.; González Martín, O.; Ramos Almeida, C.; Ruschel Dutra, D.; Ho, L. C.; Thanjavur, K.; Flohic, H.; Alonso-Herrero, A.; Lira, P.; McDermid, R.; Riffel, R. A.; Schiavon, R. P.; Winge, C.; Hoenig, M. D.; Perlman, E.

    2015-03-01

    We present spectra of the nuclear regions of 50 nearby (D = 1-92 Mpc, median = 20 Mpc) galaxies of morphological types E to Sm. The spectra, obtained with the Gemini Near-IR Spectrograph on the Gemini North telescope, cover a wavelength range of approximately 0.85-2.5 μm at R ˜ 1300-1800. There is evidence that most of the galaxies host an active galactic nucleus (AGN), but the range of AGN luminosities (log (L 2-10 keV [erg s-1]) = 37.0-43.2) in the sample means that the spectra display a wide variety of features. Some nuclei, especially the Seyferts, exhibit a rich emission-line spectrum. Other objects, in particular the type 2 Low Ionization Nuclear Emission Region galaxies, show just a few, weak emission lines, allowing a detailed view of the underlying stellar population. These spectra display numerous absorption features sensitive to the stellar initial mass function, as well as molecular bands arising in cool stars, and many other atomic absorption lines. We compare the spectra of subsets of galaxies known to be characterized by intermediate-age and old stellar populations, and find clear differences in their absorption lines and continuum shapes. We also examine the effect of atmospheric water vapor on the signal-to-noise ratio achieved in regions between the conventional NIR atmospheric windows, which are of potential interest to those planning observations of redshifted emission lines or other features affected by telluric H2O. Further exploitation of this data set is in progress, and the reduced spectra and data reduction tools are made available to the community.

  12. The nuclear near-infrared spectral properties of nearby galaxies

    NASA Astrophysics Data System (ADS)

    Mason, Rachel; Ardila, Alberto; Martins, Lucimara; Riffel, Rogerio; Gonzalez-Martin, Omaira; Ramos Almeida, Christina; Ruschel Dutra, Daniel; Ho, Luis C.; Thanjavur, Karun; Flohic, Helene; Alonso-Herrero, Almudena; Lira, Paulina; McDermid, Richard; Riffel, Rogemar A.; Schiavon, Ricardo P.; Winge, Claudia; Perlman, Eric S.; Hoenig, Michael D.

    2015-01-01

    We present spectra of the nuclear regions of 50 nearby (D = 1 - 92 Mpc, median = 20 Mpc) galaxies of morphological types E to Sm. The spectra, obtained with the Gemini Near-IR Spectrograph on the Gemini North telescope, cover a wavelength range of approximately 0.85-2.5 μm at R˜1300-1800. There is evidence that most of the galaxies host an active galactic nucleus (AGN), but the range of AGN luminosities (log (L2-10 keV [erg s-1]) = 37.0-43.2) in the sample means that the spectra display a wide variety of features. Some nuclei, especially the Seyferts, exhibit a rich emission-line spectrum. Other objects, in particular the type 2 Low Ionisation Nuclear Emission Region galaxies, show just a few, weak emission lines, allowing a detailed view of the underlying stellar population. These spectra display numerous absorption features sensitive to the stellar initial mass function, as well as molecular bands arising in cool stars, and many other atomic absorption lines. We compare the spectra of subsets of galaxies known to be characterised by intermediate-age and old stellar populations, and find clear differences in their absorption lines and continuum shapes. We also examine the effect of atmospheric water vapor on the signal-to-noise ratio achieved in regions between the conventional NIR atmospheric windows, of potential interest to those planning observations of redshifted emission lines or other features affected by telluric H2O. Further exploitation of this data set is in progress, and the reduced spectra and data reduction tools are made available to the community.

  13. Circumnuclear Regions In Barred Spiral Galaxies. 1; Near-Infrared Imaging

    NASA Technical Reports Server (NTRS)

    Perez-Ramirez, D.; Knapen, J. H.; Peletier, R. F.; Laine, S.; Doyon, R.; Nadeau, D.

    2000-01-01

    We present sub-arcsecond resolution ground-based near-infrared images of the central regions of a sample of twelve barred galaxies with circumnuclear star formation activity, which is organized in ring-like regions typically one kiloparsec in diameter. We also present Hubble Space Telescope near-infrared images of ten of our sample galaxies, and compare them with our ground-based data. Although our sample galaxies were selected for the presence of circumnuclear star formation activity, our broad-band near-infrared images are heterogeneous, showing a substantial amount of small-scale structure in some galaxies, and practically none in others. We argue that, where it exists, this structure is caused by young stars, which also cause the characteristic bumps or changes in slope in the radial profiles of ellipticity, major axis position angle, surface brightness and colour at the radius of the circumnuclear ring in most of our sample galaxies. In 7 out of 10 HST images, star formation in the nuclear ring is clearly visible as a large number of small emitting regions, organised into spiral arm fragments, which are accompanied by dust lanes. NIR colour index maps show much more clearly the location of dust lanes and, in certain cases, regions of star formation than single broad-band images. Circumnuclear spiral structure thus outlined appears to be common in barred spiral galaxies with circumnuclear star formation.

  14. THE 1.6 {mu}m NEAR-INFRARED NUCLEI OF 3C RADIO GALAXIES: JETS, THERMAL EMISSION, OR SCATTERED LIGHT?

    SciTech Connect

    Baldi, Ranieri D.; Chiaberge, Marco; Sparks, William; Macchetto, F. Duccio; Capetti, Alessandro; O'Dea, Christopher P.; Axon, David J.; Baum, Stefi A.; Quillen, Alice C.

    2010-12-20

    Using HST NICMOS 2 observations we have measured 1.6 {mu}m near-infrared nuclear luminosities of 100 3CR radio galaxies with z < 0.3, by modeling and subtracting the extended emission from the host galaxy. We performed a multiwavelength statistical analysis (including optical and radio data) of the properties of the nuclei following classification of the objects into FR I and FR II, and low-ionization galaxies (LIGs), high-ionization galaxies (HIGs), and broad-line objects (BLOs) using the radio morphology and optical spectra, respectively. The correlations among near-infrared, optical, and radio nuclear luminosity support the idea that the near-infrared nuclear emission of FR Is has a non-thermal origin. Despite the difference in radio morphology, the multiwavelength properties of FR II LIG nuclei are statistically indistinguishable from those of FR Is, an indication of a common structure of the central engine. All BLOs show an unresolved near-infrared nucleus and a large near-infrared excess with respect to FR II LIGs and FR Is of equal radio core luminosity. This requires the presence of an additional (and dominant) component other than the non-thermal light. Considering the shape of their spectral energy distribution, we ascribe the origin of their near-infrared light to hot circumnuclear dust. A near-infrared excess is also found in HIGs, but their nuclei are substantially fainter than those of BLO. This result indicates that substantial obscuration along the line of sight to the nuclei is still present at 1.6 {mu}m. Nonetheless, HIG nuclei cannot simply be explained in terms of dust obscuration: a significant contribution from light reflected in a circumnuclear scattering region is needed to account for their multiwavelength properties.

  15. The Frequency of Barred Spiral Galaxies in the Near-Infrared

    NASA Astrophysics Data System (ADS)

    Eskridge, Paul B.; Frogel, Jay A.; Pogge, Richard W.; Quillen, Alice C.; Davies, Roger L.; DePoy, D. L.; Houdashelt, Mark L.; Kuchinski, Leslie E.; Ramírez, Solange V.; Sellgren, K.; Terndrup, Donald M.; Tiede, Glenn P.

    2000-02-01

    We have determined the fraction of barred galaxies in the H-band for a statistically well-defined sample of 186 spirals drawn from the Ohio State University Bright Spiral Galaxy Survey. We find 56% of our sample to be strongly barred in the H band while another 16% is weakly barred. Only 27% of our sample is unbarred in the near-infrared. The RC3 and the Carnegie Atlas of Galaxies both classify only about 30% of our sample as strongly barred. Thus strong bars are nearly twice as prevalent in the near-infrared as in the optical. The frequency of genuine optically hidden bars is significant but lower than many claims in the literature: 40% of the galaxies in our sample that are classified as unbarred in the RC3 show evidence for a bar in the H band while the Carnegie Atlas lists this fraction as 66%. Our data reveal no significant trend in bar fraction as a function of morphology in either the optical or H band. Optical surveys of high-redshift galaxies may be strongly biased against finding bars, as bars are increasingly difficult to detect at bluer rest wavelengths. Based partially on observations obtained at the Cerro Tololo Inter-American Observatory, operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation.

  16. Physical Properties of Emission-line Galaxies at z ~ 2 from Near-infrared Spectroscopy with Magellan FIRE

    NASA Astrophysics Data System (ADS)

    Masters, Daniel; McCarthy, Patrick; Siana, Brian; Malkan, Mathew; Mobasher, Bahram; Atek, Hakim; Henry, Alaina; Martin, Crystal L.; Rafelski, Marc; Hathi, Nimish P.; Scarlata, Claudia; Ross, Nathaniel R.; Bunker, Andrew J.; Blanc, Guillermo; Bedregal, Alejandro G.; Domínguez, Alberto; Colbert, James; Teplitz, Harry; Dressler, Alan

    2014-04-01

    We present results from near-infrared spectroscopy of 26 emission-line galaxies at z ~ 2.2 and z ~ 1.5 obtained with the Folded-port InfraRed Echellette (FIRE) spectrometer on the 6.5 m Magellan Baade telescope. The sample was selected from the WFC3 Infrared Spectroscopic Parallels survey, which uses the near-infrared grism of the Hubble Space Telescope Wide Field Camera 3 (WFC3) to detect emission-line galaxies over 0.3 <~ z <~ 2.3. Our FIRE follow-up spectroscopy (R ~ 5000) over 1.0-2.5 μm permits detailed measurements of the physical properties of the z ~ 2 emission-line galaxies. Dust-corrected star formation rates for the sample range from ~5-100 M ⊙ yr-1 with a mean of 29 M ⊙ yr-1. We derive a median metallicity for the sample of 12 + log(O/H) = 8.34 or ~0.45 Z ⊙. The estimated stellar masses range from ~108.5-109.5 M ⊙, and a clear positive correlation between metallicity and stellar mass is observed. The average ionization parameter measured for the sample, log U ≈ -2.5, is significantly higher than what is found for most star-forming galaxies in the local universe, but similar to the values found for other star-forming galaxies at high redshift. We derive composite spectra from the FIRE sample, from which we measure typical nebular electron densities of ~100-400 cm-3. Based on the location of the galaxies and composite spectra on diagnostic diagrams, we do not find evidence for significant active galactic nucleus activity in the sample. Most of the galaxies, as well as the composites, are offset diagram toward higher [O III]/Hβ at a given [N II]/Hα, in agreement with other observations of z >~ 1 star-forming galaxies, but composite spectra derived from the sample do not show an appreciable offset from the local star-forming sequence on the [O III]/Hβ versus [S II]/Hα diagram. We infer a high nitrogen-to-oxygen abundance ratio from the composite spectrum, which may contribute to the offset of the high-redshift galaxies from the local star

  17. Spectral synthesis of star-forming galaxies in the near-infrared

    NASA Astrophysics Data System (ADS)

    Martins, Lucimara P.; Rodríguez-Ardila, Alberto; Diniz, Suzi; Riffel, Rogério; de Souza, Ronaldo

    2013-11-01

    The near-infrared spectral region is becoming a very useful wavelength range to detect and quantify the stellar population of galaxies. Models are developing to predict the contribution of the thermally pulsating stars on the asymptotic giant branch stars that should dominate the near-infrared region (NIR) spectra of populations 0.3 to 2 Gyr old. When present in a given stellar population, these stars leave unique signatures that can be used to detect them unambiguously. However, these models have to be tested in a homogeneous data base of star-forming galaxies, to check if the results are consistent with what is found from different wavelength ranges. In this work, we performed stellar population synthesis on the nuclear and extended regions of 23 star-forming galaxies to understand how the star formation tracers in the NIR can be used in practice. The stellar population synthesis shows that for the galaxies with strong emission in the NIR, there is an important fraction of young/intermediate population contributing to the spectra, which is probably the ionization source in these galaxies. Galaxies that had no emission lines measured in the NIR were found to have older average ages and less contribution of young populations. Although the stellar population synthesis method proved to be very effective to find the young ionizing population in these galaxies, no clear correlation between these results and the NIR spectral indexes were found. Thus, we believe that, in practice, the use of these indexes is still very limited due to observational limitations.

  18. Near-infrared imaging of barred halo-dominated low surface brightness galaxies

    NASA Astrophysics Data System (ADS)

    Honey, M.; Das, M.; Ninan, J. P.; Manoj, P.

    2016-10-01

    We present a near-infrared (NIR) imaging study of barred low surface brightness (LSB) galaxies using the TIFR1 NIR Spectrometer and Imager. LSB galaxies are dark matter dominated, late-type spirals that have low-luminosity stellar discs but large neutral hydrogen (H I) gas discs. Using Sloan Digital Sky Survey images of a very large sample of LSB galaxies derived from the literature, we found that the barred fraction is only 8.3 per cent. We imaged 25 barred LSB galaxies in the J, H, KS wavebands and 29 in the KS band. Most of the bars are much brighter than their stellar discs, which appear to be very diffuse. Our image analysis gives deprojected mean bar sizes of Rb/R25 = 0.40 and ellipticities e ≈ 0.45, which are similar to bars in high surface brightness galaxies. Thus, although bars are rare in LSB galaxies, they appear to be just as strong as bars found in normal galaxies. There is no correlation of Rb/R25 or e with the relative H I or stellar masses of the galaxies. In the (J - KS) colour images most of the bars have no significant colour gradient which indicates that their stellar population is uniformly distributed and confirms that they have low dust content.

  19. 450 d of Type II SN 2013ej in optical and near-infrared

    NASA Astrophysics Data System (ADS)

    Yuan, Fang; Jerkstrand, A.; Valenti, S.; Sollerman, J.; Seitenzahl, I. R.; Pastorello, A.; Schulze, S.; Chen, T.-W.; Childress, M. J.; Fraser, M.; Fremling, C.; Kotak, R.; Ruiter, A. J.; Schmidt, B. P.; Smartt, S. J.; Taddia, F.; Terreran, G.; Tucker, B. E.; Barbarino, C.; Benetti, S.; Elias-Rosa, N.; Gal-Yam, A.; Howell, D. A.; Inserra, C.; Kankare, E.; Lee, M. Y.; Li, K. L.; Maguire, K.; Margheim, S.; Mehner, A.; Ochner, P.; Sullivan, M.; Tomasella, L.; Young, D. R.

    2016-09-01

    We present optical and near-infrared photometric and spectroscopic observations of SN 2013ej, in galaxy M74, from 1 to 450 d after the explosion. SN 2013ej is a hydrogen-rich supernova, classified as a Type IIL due to its relatively fast decline following the initial peak. It has a relatively high peak luminosity (absolute magnitude MV = -17.6) but a small 56Ni production of ˜0.023 M⊙. Its photospheric evolution is similar to other Type II SNe, with shallow absorption in the Hα profile typical for a Type IIL. During transition to the radioactive decay tail at ˜100 d, we find the SN to grow bluer in B - V colour, in contrast to some other Type II supernovae. At late times, the bolometric light curve declined faster than expected from 56Co decay and we observed unusually broad and asymmetric nebular emission lines. Based on comparison of nebular emission lines most sensitive to the progenitor core mass, we find our observations are best matched to synthesized spectral models with a MZAMS = 12-15 M⊙ progenitor. The derived mass range is similar to but not higher than the mass estimated for Type IIP progenitors. This is against the idea that Type IIL are from more massive stars. Observations are consistent with the SN having a progenitor with a relatively low-mass envelope.

  20. Near-infrared (Fe II) and Pa Beta imaging and spectroscopy of Arp 220

    NASA Technical Reports Server (NTRS)

    Armus, L.; Shupe, D. L.; Matthews, K.; Soifer, B. T.; Neugebauer, G.

    1995-01-01

    We have imaged the ultraluminous infrared galaxy Arp 220 in light of the near-infrared (Fe II) 1.257 micron and Pa-beta lines, and have obtained spectra in the J- and H-band atmospheric windows. Arp 220 is a strong source of (Fe II) and Pa-beta emission, with luminosities of 1.3 x 10(exp 41) and 9.2 x 10(exp 40) ergs/s, respectively. The (Fe II) and Pa-beta emission are both extended over the central 2 sec-3 sec, but with different morphologies. We suggest that the extended (Fe II) emission is produced through the interaction of fast shocks with ambient gas in the interstellar medium (ISM) at the base of the outflowing, supernovae-driven superwind mapped by Heckman et al. (1987). The bolometric luminosity of the starburst required to power this wind is estimated to be at least 2 x 10(exp 11) solar luminosity. If the spatially unresolved (Fe II) emission is produced via a large number of supernova remnants, the implied rate is approximately 0.6/yr. The overall luminosity of such a starburst could account for a large fraction (1/2-1/3) of the Arp 220 energy budget, but the large deficit of ionizing photons (as counted by the Pa-beta luminosity) requires that the starburst be rapidly declining and/or have a low upper mass cutoff. Alternatively, dust may effectively compete with the gas for ionizing photons, or much of the ionizing radiation may escape through 'holes' in the ISM. It is also possible that a buried active galactic nuclei (AGN) produces a large fraction of the unresolved (Fe II) and Pa-beta emission. We briefly discuss these possibilities in light of these new imaging and spectroscopic data.

  1. Near-infrared surface photometry of bulges and disks of spiral galaxies. The data

    NASA Astrophysics Data System (ADS)

    Peletier, R. F.; Balcells, M.

    1997-03-01

    We present optical and near-infrared (NIR) surface brightness and colour profiles, in bands ranging from U to K, for the disk and bulge components of a complete sample of 30 nearby S0 to Sbc galaxies with inclinations larger than 50 °. We describe in detail the observations and the determination of colour parameters. Calibrated monochromatic and real-colour images are presented, as well as colour index maps. This data set, tailored for the study of the population characteristics of galaxy bulges, provides useful information on the colours of inner disks as well. In related papers, we have used them to quantify colour gradients in bulges, and age differentials between bulge and inner disk.

  2. Detecting high-z galaxies in the near-infrared background

    NASA Astrophysics Data System (ADS)

    Yue, Bin; Ferrara, Andrea; Helgason, Kári

    2016-06-01

    Emission from high-z galaxies must unquestionably contribute to the near-infrared background (NIRB). However, this contribution has so far proven difficult to isolate, even after subtracting the resolved galaxies to deep levels. The remaining NIRB fluctuations are dominated by unresolved low-z galaxies on small angular scales and by an unidentified component with unclear origin on large scales (≈1000 arcsec). In this article, by analysing mock maps generated from semi-numerical simulations and empirically determined LUV - Mh relations, we find that fluctuations associated with galaxies at 5 < z < 10 amount to several per cent of the unresolved NIRB flux fluctuations. We investigate the properties of this component for different survey areas and limiting magnitudes. In all cases, we show that this signal can be efficiently, and most easily at small angular scales, isolated by cross-correlating the source-subtracted NIRB with Lyman-break galaxies (LBGs) detected in the same field by Hubble Space Telescope (HST) surveys. This result provides a fresh insight into the properties of reionization sources.

  3. Near-infrared background anisotropies from diffuse intrahalo light of galaxies.

    PubMed

    Cooray, Asantha; Smidt, Joseph; De Bernardis, Francesco; Gong, Yan; Stern, Daniel; Ashby, Matthew L N; Eisenhardt, Peter R; Frazer, Christopher C; Gonzalez, Anthony H; Kochanek, Christopher S; Kozłowski, Szymon; Wright, Edward L

    2012-10-25

    Unresolved anisotropies of the cosmic near-infrared background radiation are expected to have contributions from the earliest galaxies during the epoch of reionization and from faint, dwarf galaxies at intermediate redshifts. Previous measurements were unable to pinpoint conclusively the dominant origin because they did not sample spatial scales that were sufficiently large to distinguish between these two possibilities. Here we report a measurement of the anisotropy power spectrum from subarcminute to one-degree angular scales, and find the clustering amplitude to be larger than predicted by the models based on the two existing explanations. As the shot-noise level of the power spectrum is consistent with that expected from faint galaxies, a new source population on the sky is not necessary to explain the observations. However, a physical mechanism that increases the clustering amplitude is needed. Motivated by recent results related to the extended stellar light profile in dark-matter haloes, we consider the possibility that the fluctuations originate from intrahalo stars of all galaxies. We find that the measured power spectrum can be explained by an intrahalo light fraction of 0.07 to 0.2 per cent relative to the total luminosity in dark-matter haloes of 10(9) to 10(12) solar masses at redshifts of about 1 to 4.

  4. Simulations of deep galaxy fields. 1: Monte Carlo simulations of optical and near-infrared counts

    NASA Technical Reports Server (NTRS)

    Chokshi, Arati; Lonsdale, Carol J.; Mazzei, Paola; De Zotti, Gianfranco

    1994-01-01

    Monte Carlo simulations of three-dimensional galaxy distributions are performed, following the 1988 prescription of Chokshi & Wright, to study the photometric properties of evolving galaxy populations in the optical and near-infrared bands to high redshifts. In this paper, the first of a series, we present our baseline model in which galaxy numbers are conserved, and in which no explicit 'starburst' population is included. We use the model in an attempt to simultaneously fit published blue and near-infrared photometric and spectroscopic observations of deep fields. We find that our baseline models, with a formation redshift, z(sub f), of 1000, and H(sub 0) = 50, are able to reproduce the blue counts to b(sub j) = 22, independent of the value of Omega(sub 0), and also to provide a satisfactory fit to the observed blue-band redshift distributions, but for no value of Omega(sub 0) do we achieve an acceptable fit to the fainter blue counts. In the K band, we fit the number counts to the limit of the present-day surveys only for an Omega(sub 0) = 0 cosmology. We investigate the effect on the model fits of varying the cosmological parameters H(sub 0), the formation red-shift z(sub f), and the local luminosity function. Changing H(sub 0) does not improve the fits to the observations. However, reducing the epoch of a galaxy formation used in our simulations has a substantial effect. In particular, a model with z(sub f) approximately equal to 5 in a low Omega(sub 0) universe improves the fit to the faintest photometric blue data without any need to invoke a new population of galaxies, substantial merging, or a significant starburst galaxy population. For an Omega(sub 0) = 1 universe, however, reducing z(sub f) is less successful at fitting the blue-band counts and has little effect at all at K. Varying the parameters of the local luminosity function can also have a significant effect. In particular the steep low end slope of the local luminosity function of Franceschini et

  5. The 6dF Galaxy Survey: the near-infrared Fundamental Plane of early-type galaxies

    NASA Astrophysics Data System (ADS)

    Magoulas, Christina; Springob, Christopher M.; Colless, Matthew; Jones, D. Heath; Campbell, Lachlan A.; Lucey, John R.; Mould, Jeremy; Jarrett, Tom; Merson, Alex; Brough, Sarah

    2012-11-01

    We determine the near-infrared Fundamental Plane (FP) for ˜104 early-type galaxies in the 6-degree Field Galaxy Survey (6dFGS). We fit the distribution of central velocity dispersion, near-infrared surface brightness and half-light radius with a 3D Gaussian model using a maximum-likelihood method. The model provides an excellent empirical fit to the observed FP distribution and the method proves robust and unbiased. Tests using simulations show that it gives superior results to regression techniques in the presence of significant and correlated uncertainties in all three parameters, censoring of the data by various selection effects and outliers in the data sample. For the 6dFGS J-band sample we find an FP with Re ∝ σ01.52±0.03Ie-0.89±0.01, similar to previous near-infrared determinations and consistent with the H- and K-band FPs once allowance is made for differences in mean colour. The overall scatter in Re about the FP is σr = 29 per cent, and is the quadrature sum of an 18 per cent scatter due to observational errors and a 23 per cent intrinsic scatter. Because of the Gaussian distribution of galaxies in FP space, σr is not the distance error, which we find to be σd = 23 per cent. Using group richness and local density as measures of environment, and morphologies based on visual classifications, we find that the FP slopes do not vary with environment or morphology. However, for fixed velocity dispersion and surface brightness, field galaxies are on average 5 per cent larger than galaxies in groups or higher density environments, and the bulges of early-type spirals are on average 10 per cent larger than ellipticals and lenticulars. The residuals about the FP show significant trends with environment, morphology and stellar population. The strongest trend is with age, and we speculate that age is the most important systematic source of offsets from the FP, and may drive the other trends through its correlations with environment, morphology and

  6. Physical properties of emission-line galaxies at z ∼ 2 from near-infrared spectroscopy with Magellan fire

    SciTech Connect

    Masters, Daniel; Siana, Brian; Mobasher, Bahram; Domínguez, Alberto; McCarthy, Patrick; Blanc, Guillermo; Dressler, Alan; Malkan, Mathew; Ross, Nathaniel R.; Atek, Hakim; Henry, Alaina; Martin, Crystal L.; Rafelski, Marc; Colbert, James; Hathi, Nimish P.; Scarlata, Claudia; Bunker, Andrew J.; Bedregal, Alejandro G.; Teplitz, Harry

    2014-04-20

    We present results from near-infrared spectroscopy of 26 emission-line galaxies at z ∼ 2.2 and z ∼ 1.5 obtained with the Folded-port InfraRed Echellette (FIRE) spectrometer on the 6.5 m Magellan Baade telescope. The sample was selected from the WFC3 Infrared Spectroscopic Parallels survey, which uses the near-infrared grism of the Hubble Space Telescope Wide Field Camera 3 (WFC3) to detect emission-line galaxies over 0.3 ≲ z ≲ 2.3. Our FIRE follow-up spectroscopy (R ∼ 5000) over 1.0-2.5 μm permits detailed measurements of the physical properties of the z ∼ 2 emission-line galaxies. Dust-corrected star formation rates for the sample range from ∼5-100 M {sub ☉} yr{sup –1} with a mean of 29 M {sub ☉} yr{sup –1}. We derive a median metallicity for the sample of 12 + log(O/H) = 8.34 or ∼0.45 Z {sub ☉}. The estimated stellar masses range from ∼10{sup 8.5}-10{sup 9.5} M {sub ☉}, and a clear positive correlation between metallicity and stellar mass is observed. The average ionization parameter measured for the sample, log U ≈ –2.5, is significantly higher than what is found for most star-forming galaxies in the local universe, but similar to the values found for other star-forming galaxies at high redshift. We derive composite spectra from the FIRE sample, from which we measure typical nebular electron densities of ∼100-400 cm{sup –3}. Based on the location of the galaxies and composite spectra on diagnostic diagrams, we do not find evidence for significant active galactic nucleus activity in the sample. Most of the galaxies, as well as the composites, are offset diagram toward higher [O III]/Hβ at a given [N II]/Hα, in agreement with other observations of z ≳ 1 star-forming galaxies, but composite spectra derived from the sample do not show an appreciable offset from the local star-forming sequence on the [O III]/Hβ versus [S II]/Hα diagram. We infer a high nitrogen-to-oxygen abundance ratio from the composite spectrum, which

  7. Deep near-infrared surface photometry and properties of Local Volume dwarf irregular galaxies

    NASA Astrophysics Data System (ADS)

    Young, T.; Jerjen, H.; López-Sánchez, Á. R.; Koribalski, B. S.

    2014-11-01

    We present deep H-band surface photometry and analysis of 40 Local Volume galaxies, a sample primarily composed of dwarf irregulars in the Cen A group, obtained using the Infrared Imager and Spectrograph 2 detector at the 3.9-m Anglo-Australian Telescope. We probe to a surface brightness of ˜25 mag arcsec-2, reaching a 40 times lower stellar density than the Two Micron All Sky Survey (2MASS). Employing extremely careful and rigorous cleaning techniques to remove contaminating sources, we perform surface photometry on 33 detected galaxies deriving the observed total magnitude, effective surface brightness and best-fitting Sérsic parameters. We make image quality and surface photometry comparisons to 2MASS and VISTA Hemisphere Survey demonstrating that deep targeted surveys are still the most reliable means of obtaining accurate surface photometry. We investigate the B - H colours with respect to mass for Local Volume galaxies, finding that the colours of dwarf irregulars are significantly varied, eliminating the possibility of using optical-near-infrared colour transformations to facilitate comparison to the more widely available optical data sets. The structure-luminosity relationships are investigated for our `clean' sample of dwarf irregulars. We demonstrate that a significant fraction of the Local Volume dwarf irregular population have underlying structural properties similar to both Local Volume and Virgo cluster dwarf ellipticals. Linear regressions to structure-luminosity relationships for the Local Volume galaxies and Virgo cluster dwarf ellipticals show significant differences in both slope and scatter around the established trend lines, suggesting that environment might regulate the structural scaling relationships of dwarf galaxies in comparison to their more isolated counterparts.

  8. The Interacting Galaxy Pair NGC 5394/95: Near-Infrared Photometry, Structure, and Morphology

    NASA Astrophysics Data System (ADS)

    Puerari, Ivânio; Valdez-Gutiérrez, Margarita; Hernández-López, Izbeth

    2005-10-01

    We present near-infrared observations in the J, H, and K' passbands of the interacting pair of galaxies NGC 5394/95 (KPG 404). The total magnitudes, colors, surface brightnesses, and color profiles are calculated. In addition, aperture magnitudes are compared against previous determinations. We also perform a structural (disk + bulge) analysis, as well as a two-dimensional Fourier analysis, to gain insight into the morphology of the pair. The disk + bulge fit shows that NGC 5394 (KPG 404A) is more compact than normal galaxies, while NGC 5395 (KPG 404B) is less concentrated. The two-dimensional Fourier analysis shows that NGC 5394 is an H2β galaxy in the dust-penetrated (DP) classification by Block & Puerari. NGC 5395, in contrast, displays a very complex structure that needs a number of Fourier coefficients to be explained. A tightly wound m=1 coefficient (DP class H1α) is the main structure, but other m=1 and m=2 coefficients (suggesting modulation) are also present in the Fourier spectra. The m=1 coefficients represent a pseudo-ring-type structure, indicative of a collision rather than a passage. Based on our results we are able to assert that the scenario of the interaction between the galaxy members of KPG 404 should take into account a crossing of NGC 5394 through the disk of NGC 5395 in a Cartwheel-like encounter rather than a passage as in M51-type pairs. Numerical simulations could help to unravel the structural and morphological evolution of this interacting pair.

  9. DEEP K{sub s} -NEAR-INFRARED SURFACE PHOTOMETRY OF 80 DWARF IRREGULAR GALAXIES IN THE LOCAL VOLUME

    SciTech Connect

    Fingerhut, Robin L.; McCall, Marshall L.; Argote, Mauricio; Cluver, Michelle E.; Nishiyama, Shogo; Rekola, Rami T. F.; Richer, Michael G.; Vaduvescu, Ovidiu; Woudt, Patrick A. E-mail: mccall@yorku.c E-mail: mcluver@ipac.caltech.ed E-mail: rareko@utu.f E-mail: ovidiuv@ing.iac.e

    2010-06-10

    We present deep near-infrared (K{sub s}) images and surface photometry for 80 dwarf irregular galaxies (dIs) within {approx}5 Mpc of the Milky Way. The galaxy images were obtained at five different facilities between 2004 and 2006. The image reductions and surface photometry have been performed using methods specifically designed for isolating faint galaxies from the high and varying near-infrared sky level. Fifty-four of the 80 dIs have surface brightness profiles which could be fit to a hyperbolic-secant (sech) function, while the remaining profiles could be fit to the sum of a sech and a Gaussian function. From these fits, we have measured central surface brightnesses, scale lengths, and integrated magnitudes. This survey is part of a larger study of the connection between large-scale structure and the global properties of dIs, the hypothesized building-blocks of more massive galaxies.

  10. The Araucaria Project: Near-Infrared Photometry of Cepheid Variables in the Sculptor Galaxy NGC 55

    NASA Astrophysics Data System (ADS)

    Gieren, Wolfgang; Pietrzyński, Grzegorz; Soszyński, Igor; Bresolin, Fabio; Kudritzki, Rolf-Peter; Storm, Jesper; Minniti, Dante

    2008-01-01

    We have obtained deep images in the near-infrared J and K filters of four fields in the Sculptor group spiral galaxy NGC 55 with the ESO VLT and ISAAC camera. For 40 long-period Cepheid variables in these fields, which were recently discovered by Pietrzyński et al., we have determined mean J and K magnitudes from observations at two epochs, and derived distance moduli from the observed period-luminosity (PL) relations in these bands. Using these values together with the previously measured distance moduli in the optical V and I bands, we have determined a total mean reddening of the NGC 55 Cepheids of E(B - V) = 0.127 +/- 0.019 mag, which is mostly produced inside NGC 55 itself. For the true distance modulus of the galaxy, our multiwavelength analysis yields a value of 26.434 +/- 0.037 mag (random error), corresponding to a distance of 1.94 +/- 0.03 Mpc. This value is tied to an adopted true Large Magellanic Cloud (LMC) distance modulus of 18.50 mag. The systematic uncertainty of our derived Cepheid distance to NGC 55 (apart from the uncertainty on the adopted LMC distance) is ±4%, with the main contribution likely to come from the effect of blending of some of the Cepheids with unresolved companion stars. The distance of NGC 55 derived from our multiwavelength Cepheid analysis agrees within the errors with the distance of NGC 300, strengthening the case for a physical association of these two Sculptor group galaxies. Based on observations obtained with the ESO VLT for Large Program 171.D-0004.

  11. Near-infrared polarimetry of the edge-on galaxy NGC 891

    SciTech Connect

    Montgomery, J. D.; Clemens, D. P. E-mail: clemens@bu.edu

    2014-05-01

    The edge-on galaxy NGC 891 was probed using near-infrared (NIR) imaging polarimetry in the H band (1.6 μm) with the Mimir instrument on the 1.8 m Perkins Telescope. Polarization was detected with a signal-to-noise ratio greater than three out to a surface brightness of 18.8 mag arcsec{sup –2}. The unweighted average and dispersion in polarization percentage (P) across the full disk were 0.7% and 0.3%, respectively, and the same quantities for polarization position angle (P.A.) were 12° and 19°, respectively. At least one polarization null point, where P falls nearly to zero, was detected in the northeast disk but not the southwest disk. Several other asymmetries in P between the northern and southern disk were found and may be related to spiral structure. Profiles of P and P.A. along the minor axis of NGC 891 suggest a transition from magnetic (B) field tracing dichroic polarization near the disk mid-plane to scattering dominated polarization off the disk mid-plane. A comparison between NIR P.A. and radio (3.6 cm) synchrotron polarization P.A. values revealed similar B-field orientations in the central-northeast region, which suggests that the hot plasma and cold, star-forming interstellar medium may share a common B-field. Disk-perpendicular polarizations previously seen at optical wavelengths are likely caused by scattered light from the bright galaxy center and are unlikely to be tracing poloidal B-fields in the outer disk.

  12. Star formation in grand-design, spiral galaxies. Young, massive clusters in the near-infrared

    NASA Astrophysics Data System (ADS)

    Grosbøl, P.; Dottori, H.

    2012-06-01

    Aims: Spiral structure is a prominent feature in many disk galaxies and is often outlined by bright, young objects. We study the distribution of young stellar clusters in grand-design spiral galaxies and thereby determine whether strong spiral perturbations can influence star formation. Methods: Deep, near-infrared JHK-maps were observed for ten nearby, grand-design, spiral galaxies using HAWK-I at the Very Large Telescope. Complete, magnitude-limited candidate lists of star-forming complexes were obtained by searching within the K-band maps. The properties of the complexes were derived from (H - K) - (J - H) diagrams including the identification of the youngest complexes (i.e. ≲7 Myr) and the estimation of their extinction. Results: Young stellar clusters with ages ≲7 Myr have significant internal extinction in the range of AV = 3-7m, while older ones typically have AV < 1m. The cluster luminosity function (CLF) is well-fitted by a power law with an exponent of around -2 and displays no evidence of a high luminosity cut-off. The brightest cluster complexes in the disk reach luminosities of MK = -15.5m or estimated masses of 106 M⊙. At radii with a strong, two-armed spiral pattern, the star formation rate in the arms is higher by a factor of 2-5 than in the inter-arm regions. The CLF in the arms is also shifted towards brighter MK by at least 0.4m. We also detect clusters with colors compatible with Large Magellanic Cloud intermediate age clusters and Milky Way globular clusters. The (J - K) - MK diagram of several galaxies shows, for the brightest clusters, a clear separation between young clusters that are highly attenuated by dust and older ones with low extinction. Conclusions: The gap in the (J - K) - MK diagrams implies that there has been a rapid expulsion of dust at an age around 7 Myr, possibly triggered by supernovae. Strong spiral perturbations concentrate the formation of clusters in the arm regions and shifts their CLF towards brighter magnitudes

  13. CONTAMINATION OF BROADBAND PHOTOMETRY BY NEBULAR EMISSION IN HIGH-REDSHIFT GALAXIES: INVESTIGATIONS WITH KECK'S MOSFIRE NEAR-INFRARED SPECTROGRAPH

    SciTech Connect

    Schenker, Matthew A; Ellis, Richard S; Konidaris, Nick P; Stark, Daniel P

    2013-11-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high-redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ≅ 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared with those derived assuming the broadband photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 28 3.0 < z < 3.8 Lyman break galaxies using the newly commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use these data to derive the rest-frame equivalent widths (EWs) of [O III] emission and show that these are comparable with estimates derived using the spectral energy distribution (SED) fitting technique introduced for sources of known redshift by Stark et al. Although our current sample is modest, its [O III] EW distribution is consistent with that inferred for Hα based on SED fitting of Stark et al.'s larger sample of 3.8 < z < 5 galaxies. For a subset of survey galaxies, we use the combination of optical and near-infrared spectroscopy to quantify kinematics of outflows in z ≅ 3.5 star-forming galaxies and discuss the implications for reionization measurements. The trends we uncover underline the dangers of relying purely on broadband photometry to estimate the physical properties of high-redshift galaxies and emphasize the important role of diagnostic spectroscopy.

  14. Near-infrared Hubble Space Telescope polarimetry of a complete sample of narrow-line radio galaxies

    NASA Astrophysics Data System (ADS)

    Ramírez, E. A.; Tadhunter, C. N.; Axon, D.; Batcheldor, D.; Packham, C.; Lopez-Rodriguez, E.; Sparks, W.; Young, S.

    2014-10-01

    We present an analysis of 2.05 μm Hubble Space Telescope polarimetric data for a sample of 13 nearby Fanaroff-Riley type II (FRII) 3CR radio sources (0.03 < z < 0.11) that are classified as narrow-line radio galaxies (NLRG) at optical wavelengths. We find that the compact cores of the NLRG in our sample are intrinsically highly polarized in the near-infrared (near-IR) (6 < P2.05 μm < 60 per cent), with the electric vector (E-vector) perpendicular to the radio axis in 54 per cent of the sources. The levels of extinction required to produce near-IR polarization by the dichroic extinction mechanism are consistent with the measured values recently reported in Ramírez et al., provided that this mechanism has its maximum efficiency. This consistency suggests that the nuclear polarization could be due to dichroic extinction. In this case, toroidal magnetic fields that are highly coherent would be required in the circumnuclear tori to align the elongated dust grains responsible for the dichroic extinction. However, it is not entirely possible to rule out other polarization mechanisms (e.g. scattering, synchrotron emission) with our observations at only one near-IR wavelength. Therefore, further polarimetry observations at mid-IR and radio wavelengths will be required to test whether all the near-IR polarization is due to dichroic extinction.

  15. Empirical calibration of the near-infrared Ca II triplet - III. Fitting functions

    NASA Astrophysics Data System (ADS)

    Cenarro, A. J.; Gorgas, J.; Cardiel, N.; Vazdekis, A.; Peletier, R. F.

    2002-02-01

    Using a near-infrared stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the CaII triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting functions for recently defined line-strength indices, namely CaT*, CaT and PaT, are provided. These functions can be easily implemented into stellar population models to provide accurate predictions for integrated CaII strengths. We also present a thorough study of the various error sources and their relation to the residuals of the derived fitting functions. Finally, the derived functional forms and the behaviour of the predicted CaII are compared with those of previous works in the field.

  16. The Norma cluster (ACO3627) - II. The near-infrared Ks-band luminosity function

    NASA Astrophysics Data System (ADS)

    Skelton, R. E.; Woudt, P. A.; Kraan-Korteweg, R. C.

    2009-07-01

    A deep Ks-band photometric catalogue of galaxies at the core of the rich, nearby Norma cluster (ACO3627) is presented. The survey covers about 45 × 45arcmin2 (slightly less than 1/3 Abell radius), which corresponds to ~0.8h-270Mpc2 at the adopted distance (vCMB/H0) of 70h-170Mpc of this cluster. The survey is estimated to be complete to a magnitude of . This extends into the dwarf regime, 6 mag below . The catalogue contains 390 objects, 235 of which are classified as likely or definite galaxies and 155 as candidate galaxies. The Ks-band luminosity function (LF) is constructed from the photometric sample, using a spectroscopic subsample to correct for fore and background contamination. We fit a Schechter function with a characteristic magnitude of and faint-end slope of α = -1.26 +/- 0.10 to the data. The shape of the LF is similar to those found in previous determinations of the cluster LF, in both optical and near-infrared. The Schechter parameters agree well with those of recent field LFs, suggesting that the shape of both the bright-end and the faint-end slopes are relatively insensitive to environment.

  17. Near-infrared Structure of Fast and Slow-rotating Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Schechtman-Rook, Andrew; Bershady, Matthew A.

    2014-11-01

    We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK s-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s-1 150 km s-1) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with hz <~ 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ~5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ~25% of the total K s-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{K_s}/f60 μ m ≤ 0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J - K s) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heating—or cooling—is a ubiquitous phenomenon.

  18. Measuring stellar kinematics in galaxies with the near-infrared (2-0) (12) CO absorption bandhead

    NASA Technical Reports Server (NTRS)

    Gaffney, Niall I.; Lester, Dan F.; Doppmann, Gregg

    1995-01-01

    The shape and strength of the near-infrared (2-0) (12)CO absorption bandhead provide astronomers with a unique tool for measuring stellar kinematics in galaxies with strong dust obscuration. However, the asymmetric shape of the bandhead introduces complexities when extracting the kinematics from an observed spectrum. This paper discusses the benefits, drawbacks, and observational constraints associated with using this bandhead to measure kinematics in galaxies, focusing on applications in high spectral-resolution data. Additionally, we discuss techniques found useful for extracting the kinematics from the absorption feature, and outline our success with two different methods.

  19. Visible and Near-Infrared Spectroscopy of Seyfert 1 and Narrow-Line Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, Alberto; Pastoriza, Miriani G.; Donzelli, Carlos J.

    2000-01-01

    This paper studies the continuum and emission-line properties of a sample composed of 16 normal Seyfert 1 and seven narrow-line Seyfert 1 (NLS1) galaxies using optical and near-IR CCD spectroscopy. The continuum emission of the galaxies can be described in terms of a combination of stellar population, a nonstellar continuum of power-law form, and Fe II emission. A significative difference in the optical spectral index between NLS1's and normal Seyfert 1's is observed; the latter is steeper. Most NLS1's show Fe II/Hβ ratios larger than those observed in the other Seyfert 1's. In the IRAS band, both groups of galaxies have very similar properties. We have searched for the presence of optically thin gas in the broad-line region (BLR) of the galaxies by comparing the broad O I λ8446 and Hα emission-line profiles. Our analysis show that in the NLS1's, both profiles are similar in shape and width. This result contradicts the hypothesis of thin gas emission in the high-velocity part of the BLR to explain the ``narrowness'' of broad optical permitted lines in these objects. Evidence of narrow O I λ8446 emission is found in six galaxies of our sample, implying that this line is not restricted to a pure BLR phenomenon. In the narrow-line region, we find similar luminosities in the permitted and high-ionization lines of NLS1's and normal Seyfert 1's. However, low-ionization lines such as [O I] λ6300, [O II] λ3727, and [S II] λλ6717, 6731 are intrinsically less luminous in NLS1's. Physical properties derived from density- and temperature-sensitive line ratios suggest that the [O II] and [S II] emitting zones are overlapping in normal Seyfert 1's and separated in NLS1's. Based on observations made at CASLEO. Complejo Astronómico El Leoncito (CASLEO) is operated under agreement between the Consejo Nacional de Investigaciones Científicas y técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juán.

  20. Near infrared fluorescence quenching properties of copper (II) ions for potential applications in biological imaging

    NASA Astrophysics Data System (ADS)

    Maji, Dolonchampa; Zhou, Mingzhou; Sarder, Pinaki; Achilefu, Samuel

    2014-03-01

    Fluorescence quenching properties of copper(II) ions have been used for designing Cu(II) sensitive fluorescent molecular probes. In this paper, we demonstrate that static quenching plays a key role in free Cu(II)-mediated fluorescence quenching of a near infrared (NIR) fluorescent dye cypate. The Stern-Volmer quenching constant was calculated to be KSV = 970,000 M-1 in 25 mM MES buffer, pH 6.5 at room temperature. We synthesized LS835, a compound containing cypate attached covalently to chelated Cu(II) to study fluorescence quenching by chelated Cu(II). The fluorescence quenching mechanism of chelated Cu(II) is predominantly dynamic or collisional quenching. The quenching efficiency of chelated Cu(II) was calculated to be 58% ± 6% in dimethylsulfoxide at room temperature. Future work will involve further characterization of the mechanism of NIR fluorescence quenching by Cu(II) and testing its reversibility for potential applications in designing fluorophore-quencher based molecular probes for biological imaging.

  1. Near-infrared photometry and stellar populations of first-ranked galaxies in a complete sample of nearby Abell clusters

    NASA Technical Reports Server (NTRS)

    Thuan, Trinx X.; Puschell, Jeffery J.

    1989-01-01

    Eighty-four brightest cluster members (BCMs) in the complete sample of high Galactic latitude nearby Abell clusters of Hoessel, Gunn, and Thuan (HGT) are investigated. The stellar populations in BCMs using near-infrared and optical-near-infrared colors are studied. Brighter BCMs have redder (J-K) and (V-K) colors, suggesting a metallicity increase in brighter galaxies. The larger dispersion of their colors implies that BCMs possess more heterogeneous stellar populations than their lower luminosity counterparts, the normal elliptical galaxies. Special attention is paid to BCMs associated with cooling flows. BCMs with larger accretion rates have bluer (V-K) colors due to ultraviolet excesses and are brighter in the visual wavelength region, but not in the infrared. It is suggested that part of the X-ray emitting cooling gas is converted into high- and intermediate-mass stars emitting in the blue and visible, but not in the infrared. The properties of BCMs as standard candles in the near-infrared are examined and compared with those in the optical.

  2. Near-infrared structure of fast and slow-rotating disk galaxies

    SciTech Connect

    Schechtman-Rook, Andrew; Bershady, Matthew A.

    2014-11-10

    We investigate the stellar disk structure of six nearby edge-on spiral galaxies using high-resolution JHK {sub s}-band images and three-dimensional radiative transfer models. To explore how mass and environment shape spiral disks, we selected galaxies with rotational velocities between 69 km s{sup –1} 150 km s{sup –1}) galaxies, only NGC 4013 has the super-thin+thin+thick nested disk structure seen in NGC 891 and the Milky Way, albeit with decreased oblateness, while NGC 1055, a disturbed massive spiral galaxy, contains disks with h{sub z} ≲ 200 pc. NGC 4565, another fast-rotator, contains a prominent ring at a radius ∼5 kpc but no super-thin disk. Despite these differences, all fast-rotating galaxies in our sample have inner truncations in at least one of their disks. These truncations lead to Freeman Type II profiles when projected face-on. Slow-rotating galaxies are less complex, lacking inner disk truncations and requiring fewer disk components to reproduce their light distributions. Super-thin disk components in undisturbed disks contribute ∼25% of the total K {sub s}-band light, up to that of the thin-disk contribution. The presence of super-thin disks correlates with infrared flux ratios; galaxies with super-thin disks have f{sub K{sub s}}/f{sub 60} {sub μm}≤0.12 for integrated light, consistent with super-thin disks being regions of ongoing star-formation. Attenuation-corrected vertical color gradients in (J – K {sub s}) correlate with the observed disk structure and are consistent with population gradients with young-to-intermediate ages closer to the mid-plane, indicating that disk heating—or cooling—is a ubiquitous phenomenon.

  3. Multifunctional in vivo vascular imaging using near-infrared II fluorescence

    PubMed Central

    Hong, Guosong; Lee, Jerry C.; Robinson, Joshua T.; Raaz, Uwe; Xie, Liming; Huang, Ngan F.; Cooke, John P.; Dai, Hongjie

    2013-01-01

    In vivo real-time epifluorescence imaging of mouse hindlimb vasculatures in the second near-infrared region (NIR-II, 1.1–1.4 µm) is performed using single-walled carbon nanotubes (SWNTs) as fluorophores. Both high spatial resolution (~30 µm) and temporal resolution (<200 ms/frame) for small vessel imaging are achieved 1~3 mm deep in the tissue owing to the beneficial NIR-II optical window that affords deep anatomical penetration and low scattering. This spatial resolution is unattainable by traditional NIR imaging (NIR-I, 0.75–0.9 µm) or microscopic computed tomography (micro-CT), while the temporal resolution far exceeds scanning microscopic imaging techniques. Arterial and venous vessels are unambiguously differentiated using a dynamic contrast-enhanced NIR-II imaging technique based on their distinct hemodynamics. Further, the deep tissue penetration, high spatial and temporal resolution of NIR-II imaging allow for precise quantifications of blood velocity in both normal and ischemic femoral arteries, which are beyond the capability of ultrasonography at lower blood velocity. PMID:23160236

  4. LoCuSS: the near-infrared luminosity and weak-lensing mass scaling relation of galaxy clusters

    NASA Astrophysics Data System (ADS)

    Mulroy, Sarah L.; Smith, Graham P.; Haines, Chris P.; Marrone, Daniel P.; Okabe, Nobuhiro; Pereira, Maria J.; Egami, Eiichi; Babul, Arif; Finoguenov, Alexis; Martino, Rossella

    2014-10-01

    We present the first scaling relation between weak-lensing galaxy cluster mass, MWL, and near-infrared luminosity, LK. Our results are based on 17 clusters observed with wide-field instruments on Subaru, the United Kingdom Infrared Telescope, the Mayall Telescope, and the MMT. We concentrate on the relation between projected 2D weak-lensing mass and spectroscopically confirmed luminosity within 1 Mpc, modelled as M_WL ∝ LK^b, obtaining a power-law slope of b=0.83^{+0.27}_{-0.24} and an intrinsic scatter of σ _{lnM_WL|LK}=10^{+8}_{-5} per cent. Intrinsic scatter of ˜10 per cent is a consistent feature of our results regardless of how we modify our approach to measuring the relationship between mass and light. For example, deprojecting the mass and measuring both quantities within r500, that is itself obtained from the lensing analysis, yields σ _{lnM_WL|LK}=10^{+7}_{-5} per cent and b=0.97^{+0.17}_{-0.17}. We also find that selecting members based on their (J - K) colours instead of spectroscopic redshifts neither increases the scatter nor modifies the slope. Overall our results indicate that near-infrared luminosity measured on scales comparable with r500 (typically 1 Mpc for our sample) is a low scatter and relatively inexpensive proxy for weak-lensing mass. Near-infrared luminosity may therefore be a useful mass proxy for cluster cosmology experiments.

  5. Physical Properties of Emission-Line Galaxies at 2 from Near-Infrared Spectroscopy with Magellan FIRE

    NASA Astrophysics Data System (ADS)

    Masters, Daniel C.; McCarthy, P. J.; Malkan, M. A.; Siana, B. D.; Scarlata, C.; Hathi, N. P.; Atek, H.; Henry, A. L.; WISP Team

    2014-01-01

    We present results from near-infrared spectroscopy with Magellan FIRE of 26 strong emission-line galaxies at 2.2 and 1.5. The sample was selected from the WFC3 Infrared Spectroscopic Parallels (WISP) survey, which uses the near-infrared grism capability of the Hubble Space Telescope Wide Field Camera 3 to detect emission-line galaxies over 0.5 < z < 2.3. High-resolution ( 5000) follow-up spectroscopy with Magellan FIRE over 1.0--2.5 microns resolves important rest-frame optical emission lines, allowing us to measure physical properties such as dust obscuration, metal abundance, star formation rate, ionization parameter, and emission line kinematics. We also analyze the properties of composite spectra derived from the FIRE-observed sample. With this relatively large sample of rest-frame optical spectra we can make statistical inferences about the population of emission-line galaxies at 2. We find that the galaxies are low metallicity ( 1/5-1/2 Z_solar) as determined from the R23 calibration. The galaxies are low dust extinction on average (E(B-V 0.2) but with significant scatter. The dust-corrected H-alpha star formation rates range from ~10--150 M_sun yr^-1 with a mean of 50 M_su yr^-1. The average ionization parameter for the sample, log U ~ -2.5, is higher than typically found for star-forming galaxies in the local universe but consistent with those found in more intense starbursting regions in galaxies such as M82. Emission line velocity dispersions are measured to be 71 +- 38 km s^-1, in good agreement with other studies that have probed the H-alpha kinematics of star-forming galaxies at similar redshift. The galaxies are compact, with half-light radii of < 2 kpc, and ~50% show evidence for multiple structures or asymmetries in the WFC3 imaging. Based on the line velocity dispersions and the location of the galaxies on BPT diagnostic plots, there is little evidence for significant AGN contribution to most emission-line galaxies at 2.

  6. The mass-metallicity and fundamental metallicity relations at z > 2 using very large telescope and Subaru near-infrared spectroscopy of zCOSMOS galaxies

    SciTech Connect

    Maier, C.; Ziegler, B. L.; Lilly, S. J.; Peng, Y.; Contini, T.; Pérez Montero, E.; Balestra, I.

    2014-09-01

    In the local universe, there is good evidence that, at a given stellar mass M, the gas-phase metallicity Z is anti-correlated with the star formation rate (SFR) of the galaxies. It has also been claimed that the resulting Z(M, SFR) relation is invariant with redshift—the so-called 'fundamental metallicity relation' (FMR). Given a number of difficulties in determining metallicities, especially at higher redshifts, the form of the Z(M, SFR) relation and whether it is really independent of redshift is still very controversial. To explore this issue at z > 2, we used VLT-SINFONI and Subaru-MOIRCS near-infrared spectroscopy of 20 zCOSMOS-deep galaxies at 2.1 < z < 2.5 to measure the strengths of up to five emission lines: [O II] λ3727, Hβ, [O III] λ5007, Hα, and [N II] λ6584. This near-infrared spectroscopy enables us to derive O/H metallicities, and also SFRs from extinction corrected Hα measurements. We find that the mass-metallicity relation (MZR) of these star-forming galaxies at z ≈ 2.3 is lower than the local Sloan Digital Sky Survey (SDSS) MZR by a factor of three to five, a larger change than found by Erb et al. using [N II]/Hα-based metallicities from stacked spectra. We discuss how the different selections of the samples and metallicity calibrations used may be responsible for this discrepancy. The galaxies show direct evidence that the SFR is still a second parameter in the MZR at these redshifts. However, determining whether the Z(M, SFR) relation is invariant with epoch depends on the choice of extrapolation used from local samples, because z > 2 galaxies of a given mass have much higher SFRs than the local SDSS galaxies. We find that the zCOSMOS galaxies are consistent with a non-evolving FMR if we use the physically motivated formulation of the Z(M, SFR) relation from Lilly et al., but not if we use the empirical formulation of Mannucci et al.

  7. Empirical calibration of the near-infrared CaII triplet - IV. The stellar population synthesis models

    NASA Astrophysics Data System (ADS)

    Vazdekis, A.; Cenarro, A. J.; Gorgas, J.; Cardiel, N.; Peletier, R. F.

    2003-04-01

    We present a new evolutionary stellar population synthesis model, which predicts spectral energy distributions for single-age single-metallicity stellar populations (SSPs) at resolution 1.5 Å (FWHM) in the spectral region of the near-infrared CaII triplet feature. The main ingredient of the model is a new extensive empirical stellar spectral library that has been recently presented by Cenarro et al., which is composed of more than 600 stars with an unprecedented coverage of the stellar atmospheric parameters. Two main products of interest for stellar population analysis are presented. The first is a spectral library for SSPs with metallicities -1.7 < [Fe/H] < +0.2, a large range of ages (0.1-18 Gyr) and initial mass function (IMF) types. They are well suited to modelling galaxy data, since the SSP spectra, with flux-calibrated response curves, can be smoothed to the resolution of the observational data, taking into account the internal velocity dispersion of the galaxy, allowing the user to analyse the observed spectrum in its own system. We also produce integrated absorption-line indices (namely CaT*, CaT and PaT) for the same SSPs in the form of equivalent widths. We find the following behaviour for the CaII triplet feature in old-aged SSPs: (i) the strength of the CaT* index does not change much with time for all metallicities for ages larger than ~3 Gyr; (ii) this index shows a strong dependence on metallicity for values below [M/H]~-0.5 and (iii) for larger metallicities this feature does not show a significant dependence either on age or on the metallicity, being more sensitive to changes in the slope of power-like IMF shapes. The SSP spectra have been calibrated with measurements for globular clusters by Armandroff & Zinn, which are well reproduced, probing the validity of using the integrated CaII triplet feature for determining the metallicities of these systems. Fitting the models to two early-type galaxies of different luminosities (NGC 4478 and 4365

  8. Spectroscopic pilot study in the near infrared of a sample of star-forming galaxies at z = 2

    NASA Astrophysics Data System (ADS)

    Gallego, J.; Sánchez de Miguel, A.; Zamorano, J.; Pérez-González, P. G.; Cardiel, N.; Barro, G.

    2011-11-01

    In this work we present the results of the spectroscopic analysis inthe near-infrared K band of a sample of 12 active star forminggalaxies at z ˜ 2. The sample was selected by using photometricredshifts, blue colors and large fluxes in the 24 μ m band ofMIPS/Spitzer. To analyze their physical properties we have computedtheir sizes, colors, stellar masses, extinctions and other parametersavailable in literature and in the "Rainbow" database. We computeHα luminosities and star formation rates for all galaxies atthat redshift. We were able to estimate metallicities from [NII]6584for a sub sample of the objects. In particular the dependence of the metallicitywith the stellar mass has been studied and compared with the results of other samples ofgalaxies at several redshifts. For a fixed mass, the metallicities ofour galaxies are compatible than those similar at the corresponding redshift, following the general trend of lower metallicities for higher redshifts.

  9. VLT/X-SHOOTER NEAR-INFRARED SPECTROSCOPY AND HST IMAGING OF GRAVITATIONALLY LENSED z ∼ 2 COMPACT QUIESCENT GALAXIES

    SciTech Connect

    Geier, S.; Man, A. W. S.; Krühler, T.; Toft, S.; Fynbo, J. P. U.; Richard, J.; Marchesini, D.

    2013-11-10

    Quiescent massive galaxies at z ∼ 2 are thought to be the progenitors of present-day massive ellipticals. Observations revealed them to be extraordinarily compact. Until now, the determination of stellar ages, star formation rates, and dust properties via spectroscopic measurements has been feasible only for the most luminous and massive specimens (∼3 × M*). Here we present a spectroscopic study of two near-infrared-selected galaxies that are close to the characteristic stellar mass M* (∼0.9 × M* and ∼1.3 × M*) and whose observed brightness has been boosted by the gravitational lensing effect. We measure the redshifts of the two galaxies to be z = 1.71 ± 0.02 and z = 2.15 ± 0.01. By fitting stellar population synthesis models to their spectrophotometric spectral energy distributions we determine their ages to be 2.4{sup +0.8}{sub -0.6} Gyr and 1.7 ± 0.3 Gyr, respectively, which implies that the two galaxies have higher mass-to-light ratios than most quiescent z ∼ 2 galaxies in other studies. We find no direct evidence for active star formation or active galactic nucleus activity in either of the two galaxies, based on the non-detection of emission lines. Based on the derived redshifts and stellar ages we estimate the formation redshifts to be z=4.3{sup +3.4}{sub -1.2} and z=4.3{sup +1.0}{sub -0.6}, respectively. We use the increased spatial resolution due to the gravitational lensing to derive constraints on the morphology. Fitting Sérsic profiles to the de-lensed images of the two galaxies confirms their compactness, with one of them being spheroid-like and the other providing the first confirmation of a passive lenticular galaxy at a spectroscopically derived redshift of z ∼ 2.

  10. VizieR Online Data Catalog: LSB galaxies in near-infrared. III. (Monnier-Ragaigne+, 2003)

    NASA Astrophysics Data System (ADS)

    Monnier Ragaigne, D.; van Driel, W.; Schneider, S. E.; Balkowski, C.; Jarrett, T. H.

    2003-09-01

    A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H I line using the Nancay telescope. All have a Ks-band mean central surface brightness, measured within a 5" radius, fainter than 18mag/arcsec2 and a Ks-band isophotal radius at the 20mag/arcsec2 level larger than 20". We present global H I line parameters for the 171 clearly detected objects and the 23 marginal detections, as well as upper limits for the undetected objects. The 171 clear detections comprise 50 previously uncatalogued objects and 41 objects with a PGC entry only. (15 data files).

  11. Upconverting Nanoparticles Prompt Remote Near-Infrared Photoactivation of Ru(II)-Arene Complexes.

    PubMed

    Ruggiero, Emmanuel; Garino, Claudio; Mareque-Rivas, Juan C; Habtemariam, Abraha; Salassa, Luca

    2016-02-18

    The synthesis and full characterisation (including X-ray diffraction studies and DFT calculations) of two new piano-stool Ru(II) -arene complexes, namely [(η(6) -p-cym)Ru(bpy)(m-CCH-Py)][(PF)6]2 (1) and [(η(6) -p-cym)Ru(bpm)(m-CCH-Py)][(PF)6]2 (2; p-cym=p-cymene, bpy=2,2'-bipyridine, bpm=2,2'-bipyrimidine, and m-CCH-Py=3-ethynylpyridine), is described and discussed. The reaction of the m-CCH-Py ligand of 1 and 2 with diethyl-3-azidopropyl phosphonate by Cu-catalysed click chemistry affords [(η(6) -p-cym)Ru(bpy)(P-Trz-Py)][(PF)6]2 (3) and [(η(6) -p-cym)Ru(bpm)(P-Trz-Py)][(PF)6]2 (4; P-Trz-Py=[3-(1-pyridin-3-yl-[1,2,3]triazol-4-yl)-propyl]phosphonic acid diethyl ester). Upon light excitation at λ=395 nm, complexes 1-4 photodissociate the monodentate pyridyl ligand and form the aqua adduct ions [(η(6) -p-cym)Ru(bpy)(H2O)](2+) and [(η(6) -p-cym)Ru(bpm)(H2O)](2+). Thulium -doped upconverting nanoparticles (UCNPs) are functionalised with 4, thus exploiting their surface affinity for the phosphonate group in the complex. The so-obtained nanosystem UCNP@4 undergoes near-infrared (NIR) photoactivation at λ=980 nm, thus producing the corresponding reactive aqua species that binds the DNA-model base guanosine 5'-monophosphate. PMID:26785101

  12. THE ARAUCARIA PROJECT: THE DISTANCE TO THE SCULPTOR GALAXY NGC 247 FROM NEAR-INFRARED PHOTOMETRY OF CEPHEID VARIABLES

    SciTech Connect

    Gieren, Wolfgang; Pietrzynski, Grzegorz; Szewczyk, Olaf; Soszynski, Igor; Bresolin, Fabio; Kudritzki, Rolf-Peter; Urbaneja, Miguel A.; Storm, Jesper; Minniti, Dante; GarcIa-Varela, Alejandro E-mail: szewczyk@astro-udec.cl E-mail: soszynsk@astrouw.edu.pl E-mail: kud@ifa.hawaii.edu E-mail: jstorm@aip.de

    2009-08-01

    We have obtained deep near-infrared images in J and K filters of four fields in the Sculptor Group spiral galaxy NGC 247 with the ESO VLT and Infrared Spectrometer and Array Camera. For a sample of 10 Cepheids in these fields, previously discovered by GarcIa-Varela et al. from optical wide-field images, we have determined mean J and K magnitudes and have constructed the period-luminosity (PL) relations in these bands. Using the near-infrared PL relations together with those in the optical V and I bands, we have determined a true distance modulus for NGC 247 of 27.64 mag, with a random uncertainty of {+-}2% and a systematic uncertainty of {approx}4% which is dominated by the effect of unresolved stars on the Cepheid photometry. The mean reddening affecting the NGC 247 Cepheids of E(B - V) = 0.18 {+-} 0.02 mag is mostly produced in the host galaxy itself and is significantly higher than what was found in the previous optical Cepheid studies in NGC 247 of our own group, and Madore et al., leading to a 7% decrease in the previous optical Cepheid distance. As in other studies of our project, the distance modulus of NGC 247 we report is tied to an assumed Large Magellanic Cloud distance modulus of 18.50. Comparison with other distance measurements to NGC 247 shows that the present IR-based Cepheid distance is the most accurate among these determinations. With a distance of 3.4 Mpc, NGC 247 is about 1.5 Mpc more distant than NGC 55 and NGC 300, two other Sculptor Group spirals analyzed before with the same technique by our group.

  13. DEEP NEAR-INFRARED SPECTROSCOPY OF PASSIVELY EVOLVING GALAXIES AT z {approx}> 1.4

    SciTech Connect

    Onodera, M.; Carollo, M.; Lilly, S.; Renzini, A.; Mancini, C.; Cappellari, M.; Strazzullo, V.; Daddi, E.; Gobat, R.; McCracken, H. J.; Ilbert, O.; Capak, P.; Cimatti, A.; Giavalisco, M.; Koekemoer, A. M.; Kong, X.; Motohara, K.; Ohta, K.; and others

    2012-08-10

    We present the results of new near-IR spectroscopic observations of passive galaxies at z {approx}> 1.4 in a concentration of BzK-selected galaxies in the COSMOS field. The observations have been conducted with Subaru/MOIRCS, and have resulted in absorption lines and/or continuum detection for 18 out of 34 objects. This allows us to measure spectroscopic redshifts for a sample that is almost complete to K{sub AB} = 21. COSMOS photometric redshifts are found in fair agreement overall with the spectroscopic redshifts, with a standard deviation of {approx}0.05; however, {approx}30% of objects have photometric redshifts systematically underestimated by up to {approx}25%. We show that these systematic offsets in photometric redshifts can be removed by using these objects as a training set. All galaxies fall in four distinct redshift spikes at z = 1.43, 1.53, 1.67, and 1.82, with this latter one including seven galaxies. SED fits to broadband fluxes indicate stellar masses in the range of {approx}4-40 Multiplication-Sign 10{sup 10} M{sub Sun} and that star formation was quenched {approx}1 Gyr before the cosmic epoch at which they are observed. The spectra of several individual galaxies have allowed us to measure their H{delta}{sub F} indices and the strengths of the 4000 A break, which confirms their identification as passive galaxies, as does a composite spectrum resulting from the co-addition of 17 individual spectra. The effective radii of the galaxies have been measured on the COSMOS HST/ACS i{sub F814W}-band image, confirming the coexistence at these redshifts of passive galaxies, which are substantially more compact than their local counterparts with others that follow the local effective radius-stellar mass relation. For the galaxy with the best signal-to-noise spectrum we were able to measure a velocity dispersion of 270 {+-} 105 km s{sup -1} (error bar including systematic errors), indicating that this galaxy lies closely on the virial relation given its stellar

  14. AKARI NEAR-INFRARED SPECTROSCOPIC OBSERVATIONS OF INTERSTELLAR ICES IN THE EDGE-ON STARBURST GALAXY NGC 253

    SciTech Connect

    Yamagishi, Mitsuyoshi; Kaneda, Hidehiro; Ishihara, Daisuke; Oyabu, Shinki; Onaka, Takashi; Shimonishi, Takashi; Suzuki, Toyoaki

    2011-04-10

    We present the spatially resolved near-infrared (2.5-5.0 {mu}m) spectra of the edge-on starburst galaxy NGC 253 obtained with the Infrared Camera on board AKARI. Near the center of the galaxy, we clearly detect the absorption features of interstellar ices (H{sub 2}O: 3.05 {mu}m, CO{sub 2}: 4.27 {mu}m, and XCN: 4.62 {mu}m) and the emission of polycyclic aromatic hydrocarbons (PAHs) at 3.29 {mu}m and the hydrogen recombination line Br{alpha} at 4.05 {mu}m. We find that the distributions of the ices differ from those of the PAH and gas. We calculate the column densities of the ices and derive the abundance ratios of N(CO{sub 2})/N(H{sub 2}O) = 0.17 {+-} 0.05. They are similar to those obtained around the massive young stellar objects in our Galaxy (0.17 {+-} 0.03), although a much stronger interstellar radiation field and higher dust temperature are expected near the center of NGC 253.

  15. Observational studies on the near-infrared unidentified emission bands in galactic H II regions

    SciTech Connect

    Mori, Tamami I.; Onaka, Takashi; Sakon, Itsuki; Ohsawa, Ryou; Bell, Aaron C.; Ishihara, Daisuke; Shimonishi, Takashi

    2014-03-20

    Using a large collection of near-infrared spectra (2.5-5.4 μm) of Galactic H II regions and H II region-like objects, we perform a systematic investigation of astronomical polycyclic aromatic hydrocarbon (PAH) features. Thirty-six objects were observed using the infrared camera on board the AKARI satellite as a part of a director's time program. In addition to the well known 3.3-3.6 μm features, most spectra show a relatively weak emission feature at 5.22 μm with sufficient signal-to-noise ratios, which we identify as the PAH 5.25 μm band (previously reported). By careful analysis, we find good correlations between the 5.25 μm band and both the aromatic hydrocarbon feature at 3.3 μm and the aliphatic hydrocarbon features at around 3.4-3.6 μm. The present results give us convincing evidence that the astronomical 5.25 μm band is associated with C-H vibrations, as suggested by previous studies, and show its potential to probe the PAH size distribution. The analysis also shows that the aliphatic-to-aromatic ratio of I {sub 3.4-3.6} {sub μm}/I {sub 3.3} {sub μm} decreases against the ratio of the 3.7 μm continuum intensity to the 3.3 μm band, I {sub cont,} {sub 3.7} {sub μm}/I {sub 3.3} {sub μm}, which is an indicator of the ionization fraction of PAHs. The midinfrared color of I {sub 9} {sub μm}/I {sub 18} {sub μm} also declines steeply against the ratio of the hydrogen recombination line Brα at 4.05 μm to the 3.3 μm band, I {sub Brα}/I {sub 3.3} {sub μm}. These facts indicate possible dust processing inside or at the boundary of ionized gas.

  16. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Luminosity Functions and Density Profiles

    SciTech Connect

    Muzzin, Adam; Yee, H.K.C.; Hall, Patrick B.; Ellingson, E.; Lin, Huan; /Fermilab

    2006-12-01

    We present K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters. The extensive spectroscopic dataset available for these clusters allows us to determine the cluster K-band luminosity function and density profile without the need for statistical background subtraction. The luminosity density and number density profiles can be described by NFW models with concentration parameters of c{sub l} = 4.28 {+-} 0.70 and c{sub g} = 4.13 {+-} 0.57 respectively. Comparing these to the dynamical mass analysis of the same clusters shows that the galaxy luminosity and number density profiles are similar to the dark matter profile, and are not less concentrated like in local clusters. The luminosity functions show that the evolution of K. over the redshift range 0.2 < z < 0.5 is consistent with a scenario where the majority of stars in cluster galaxies form at high-redshift (z{sub f} > 1.5) and evolve passively thereafter. The best-fit for the faint-end slope of the luminosity function is {alpha} = -0.84 {+-} 0.08, which indicates that it does not evolve between z = 0 and z = 0.3. Using Principal Component Analysis of the spectra we classify cluster galaxies as either star-forming/recently-star-forming (EM+BAL) or non-star forming (ELL) and compute their respective luminosity functions. The faint-end slope of the ELL luminosity function is much shallower than for the EM+BAL galaxies at z = 0.3, and suggests the number of faint ELL galaxies in clusters decreases by a factor of {approx} 3 from z = 0 to z = 0.3. The redshift evolution of K* for both EM+BAL and ELL types is consistent with a passively evolving stellar population formed at high-redshift. Passive evolution in both classes, as well as the total cluster luminosity function, demonstrates that the bulk of the stellar population in all bright cluster galaxies is formed at high-redshift and subsequent transformations in morphology/color/spectral-type have little effect on the total stellar

  17. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    SciTech Connect

    Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

    2013-02-01

    We performed a near-infrared spectroscopic survey toward an area of {approx}10 deg{sup 2} of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R {approx} 20) spectra in 2-5 {mu}m for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 {mu}m, and 67% of the sources also have photometric data up to 24 {mu}m. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 {mu}m can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the

  18. NEAR-INFRARED ADAPTIVE OPTICS IMAGING OF INFRARED LUMINOUS GALAXIES: THE BRIGHTEST CLUSTER MAGNITUDE-STAR FORMATION RATE RELATION

    SciTech Connect

    Randriamanakoto, Z.; Väisänen, P.; Escala, A.; Kankare, E.; Kotilainen, J.; Mattila, S.; Ryder, S.

    2013-10-01

    We have established a relation between the brightest super star cluster (SSC) magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near-infrared (NIR). The data come from a statistical sample of ∼40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, M{sub K} ∼ –2.6log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude versus SFR dependency.

  19. Optical and Near Infrared studies of the photometric structure and starburst activity of Blue Compact Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Noeske, K. G.

    2003-03-01

    This thesis describes three studies of Blue Compact Dwarf Galaxies (BCDs), focussed on the structure of the stellar components, the star-forming activity, and the environment of such galaxies, as well as the physical background of their morphological variety. The analysis of deep Near Infrared (NIR) image data of a significant sample of BCDs allows to study the evolved stellar low surface brightness (LSB) components of BCDs more precisely than previous studies at visible wavelengths. Azimuthally averaged radial surface brightness profiles (SBPs) show an exponential intensity distribution of the stellar LSB components at large galactocentric radii. This result, along with the derived exponential scale lengths which are systematically smaller than those of dwarf Irregular and dwarf Elliptical galaxies, agrees with previous optical studies. Towards smaller radii, however, the NIR data reveal an inwards-flattening of the SBPs of the stellar LSB components with respect to their outer exponential slopes in more than half of the BCDs under study. Such inwards-flattening exponential SBPs are frequent in dwarf Irregulars and dwarf Ellipticals, but were hitherto largely undiscovered in the stellar hosts of BCDs. The physical origin of such SBPs in dwarf galaxies is to date not understood. Empirical approaches to their systematization and quantitative investigation are discussed, along with the various implications of the discovery of such SBPs in many BCDs for the understanding of such galaxies. Based on the derived structural information on the stellar LSB components and the starburst components, the hypothesis is raised that below a certain threshold density of the stellar LSB component, of the order of 0.4 solar masses per cubic parsec, burst-like star formation does not occur in gas-rich dwarf galaxies. On this hypothesis, the observed relations between the structure of the stellar LSB components of BCDs and their luminosity can be reproduced, as well as the systematic

  20. The Munich Near-Infrared Cluster Survey - IX. Galaxy evolution to z ~ 2 from optically selected catalogues†‡

    NASA Astrophysics Data System (ADS)

    Feulner, Georg; Goranova, Yuliana; Hopp, Ulrich; Gabasch, Armin; Bender, Ralf; Botzler, Christine S.; Drory, Niv

    2007-06-01

    We present B-, R- and I-band-selected galaxy catalogues based on the Munich Near-Infrared Cluster Survey (MUNICS) which, together with the previously used K-selected sample, serve as an important probe of galaxy evolution in the redshift range 0 <~ z <~ 2. Furthermore, used in comparison they are ideally suited to study selection effects in extragalactic astronomy. The construction of the B-, R- and I-selected photometric catalogues, containing ~9000, ~9000 and ~6000 galaxies, respectively, is described in detail. The catalogues reach 50 per cent completeness limits for point sources of B ~= 24.5 mag, R ~= 23.5 mag and I ~= 22.5 mag and cover an area of about 0.3deg2. Photometric redshifts are derived for all galaxies with an accuracy of δz/(1 + z) ~= 0.057, very similar to the K-selected sample. Galaxy number counts in the B, V, R, I, J and K bands demonstrate the quality of the data set. The rest-frame colour distributions of galaxies at different selection bands and redshifts suggest that the most-massive galaxies have formed the bulk of their stellar population at earlier times and are essentially in place at redshift unity. We investigate the influence of selection band and environment on the specific star formation rate (SSFR). We find that K-band selection indeed comes close to selection in stellar mass, while B-band selection purely selects galaxies in SFR. We use a galaxy group catalogue constructed on the K-band-selected MUNICS sample to study possible differences of the SSFR between the field and the group environment, finding a marginally lower average SSFR in groups as compared to the field, especially at lower redshifts. The field-galaxy luminosity function in the B and R band as derived from the R-selected sample evolves out to z ~= 2 in the sense that the characteristic luminosity increases but the number density decreases. This effect is smaller at longer rest-frame wavelengths and gets more pronounced at shorter wavelengths. Parametrizing the

  1. Near-Infrared Integral Field Spectroscopy and Mid-Infrared Spectroscopy of the Starburst Galaxy M82

    NASA Astrophysics Data System (ADS)

    Förster Schreiber, N. M.; Genzel, R.; Lutz, D.; Kunze, D.; Sternberg, A.

    2001-05-01

    We present new infrared observations of the central regions of the starburst galaxy M82. The observations consist of near-infrared integral field spectroscopy in the H and K bands obtained with the MPE 3D instrument and of λ=2.4-45 μm spectroscopy from the Short Wavelength Spectrometer (SWS) onboard the Infrared Space Observatory. These measurements are used, together with data from the literature, to (1) reexamine the controversial issue of extinction, (2) determine the physical conditions of the interstellar medium (ISM) within the star-forming regions, and (3) characterize the composition of the stellar populations. Our results provide a set of constraints for detailed starburst modeling, which we present in a companion paper. We find that purely foreground extinction cannot reproduce the global relative intensities of H recombination lines from optical to radio wavelengths. A good fit is provided by a homogeneous mixture of dust and sources, and with a visual extinction of AV=52 mag. The SWS data provide evidence for deviations from commonly assumed extinction laws between 3 and 10 μm. The fine-structure lines of Ne, Ar, and S detected with SWS imply an electron density of ~300 cm-3, and abundance ratios Ne/H and Ar/H nearly solar and S/H about one-fourth solar. The excitation of the ionized gas indicates an average effective temperature for the OB stars of 37,400 K, with little spatial variation across the starburst regions. We find that a random distribution of closely packed gas clouds and ionizing clusters and an ionization parameter of ~10-2.3 represent well the star-forming regions on spatial scales ranging from a few tens to a few hundreds of parsecs. From detailed population synthesis and the mass-to-K-light ratio, we conclude that the near-infrared continuum emission across the starburst regions is dominated by red supergiants with average effective temperatures ranging from 3600 to 4500 K and roughly solar metallicity. Our data rule out significant

  2. DEEP NEAR-INFRARED SURVEY OF THE PIPE NEBULA. II. DATA, METHODS, AND DUST EXTINCTION MAPS

    SciTech Connect

    Roman-Zuniga, Carlos G.; Lada, Charles J.; Lombardi, Marco

    2010-12-20

    We present a new set of high-resolution dust extinction maps of the nearby and essentially starless Pipe Nebula molecular cloud. The maps were constructed from a concerted deep near-infrared imaging survey with the ESO-VLT, ESO-NTT, CAHA 3.5 m telescopes, and 2MASS data. The new maps have a resolution three times higher than the previous extinction map of this cloud by Lombardi et al. and are able to resolve structures down to 2600 AU. We detect 244 significant extinction peaks across the cloud. These peaks have masses between 0.1 and 18.4 M{sub sun}, diameters between 1.2 and 5.7 x 10{sup 4} AU (0.06 and 0.28 pc), and mean densities of about 10{sup 4} cm{sup -3}, all in good agreement with previous results. From the analysis of the mean surface density of companions we find a well-defined scale near 1.4 x 10{sup 4} AU below which we detect a significant decrease in structure of the cloud. This scale is smaller than the Jeans length calculated from the mean density of the peaks. The surface density of peaks is not uniform but instead it displays clustering. Extinction peaks in the Pipe Nebula appear to have a spatial distribution similar to the stars in Taurus, suggesting that the spatial distribution of stars evolves directly from the primordial spatial distribution of high-density material.

  3. Near-infrared Spectra and Intrinsic Luminosities of Candidate Type II Quasars at 2 < z < 3.4

    NASA Astrophysics Data System (ADS)

    Greene, Jenny E.; Alexandroff, Rachael; Strauss, Michael A.; Zakamska, Nadia L.; Lang, Dustin; Liu, Guilin; Pattarakijwanich, Petchara; Hamann, Frederick; Ross, Nicholas P.; Myers, Adam D.; Brandt, W. Niel; York, Donald; Schneider, Donald P.

    2014-06-01

    We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey (SDSS), using Triplespec on the Apache Point Observatory 3.5 m telescope, the Folded-port InfraRed Echellette at the Magellan/Baade 6.5 m telescope, and the Gemini Near-Infrared Spectrograph on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of C IV and Ly α, with FWHM < 2000 km s-1 from the SDSS pipeline. We use the [O III] λ5007 line shape as a model for the narrow-line region emission and find that Hα consistently requires a broad component with FWHMs ranging from 1000 to 7500 km s-1. Interestingly, the C IV lines also require broad bases, but with considerably narrower widths of 1000-4500 km s-1. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [O III] line, we find typical AV values of 0-2 mag, which naturally explains the attenuated C IV lines relative to Hα. We propose that our targets are moderately obscured quasars. We also describe one unusual object with three distinct velocity peaks in its [O III] spectrum.

  4. Near-infrared spectra and intrinsic luminosities of candidate type II quasars at 2 < z < 3.4

    SciTech Connect

    Greene, Jenny E.; Strauss, Michael A.; Pattarakijwanich, Petchara; Alexandroff, Rachael; Zakamska, Nadia L.; Liu, Guilin; Lang, Dustin; Hamann, Frederick; Ross, Nicholas P.; Myers, Adam D.; Brandt, W. Niel; Schneider, Donald P.; York, Donald

    2014-06-10

    We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey (SDSS), using Triplespec on the Apache Point Observatory 3.5 m telescope, the Folded-port InfraRed Echellette at the Magellan/Baade 6.5 m telescope, and the Gemini Near-Infrared Spectrograph on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of C IV and Ly α, with FWHM < 2000 km s{sup –1} from the SDSS pipeline. We use the [O III] λ5007 line shape as a model for the narrow-line region emission and find that Hα consistently requires a broad component with FWHMs ranging from 1000 to 7500 km s{sup –1}. Interestingly, the C IV lines also require broad bases, but with considerably narrower widths of 1000-4500 km s{sup –1}. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [O III] line, we find typical A{sub V} values of 0-2 mag, which naturally explains the attenuated C IV lines relative to Hα. We propose that our targets are moderately obscured quasars. We also describe one unusual object with three distinct velocity peaks in its [O III] spectrum.

  5. The black hole mass of NGC 4151. II. Stellar dynamical measurement from near-infrared integral field spectroscopy

    SciTech Connect

    Onken, Christopher A.; Ferrarese, Laura; Valluri, Monica; Brown, Jonathan S.; McGregor, Peter J.; Peterson, Bradley M.; Pogge, Richard W.; Bentz, Misty C.; Vestergaard, Marianne; Storchi-Bergmann, Thaisa; Riffel, Rogemar A. E-mail: mvalluri@umich.edu

    2014-08-10

    We present a revised measurement of the mass of the central black hole (M{sub BH} ) in the Seyfert 1 galaxy NGC 4151. The new stellar dynamical mass measurement is derived by applying an axisymmetric orbit-superposition code to near-infrared integral field data obtained using adaptive optics with the Gemini Near-infrared Integral Field Spectrograph (NIFS). When our models attempt to fit both the NIFS kinematics and additional low spatial resolution kinematics, our results depend sensitively on how χ{sup 2} is computed—probably a consequence of complex bar kinematics that manifest immediately outside the nuclear region. The most robust results are obtained when only the high spatial resolution kinematic constraints in the nuclear region are included in the fit. Our best estimates for the black hole mass and H-band mass-to-light ratio are M{sub BH} ∼ 3.76 ± 1.15 × 10{sup 7} M{sub ☉} (1σ error) and Y{sub H} ∼ 0.34 ± 0.03 M{sub ☉}/L{sub ☉} (3σ error), respectively (the quoted errors reflect the model uncertainties). Our black hole mass measurement is consistent with estimates from both reverberation mapping (3.57{sub −0.37}{sup +0.45}×10{sup 7} M{sub ⊙}) and gas kinematics (3.0{sub −2.2}{sup +0.75}×10{sup 7} M{sub ⊙}; 1σ errors), and our best-fit mass-to-light ratio is consistent with the photometric estimate of Y{sub H} = 0.4 ± 0.2 M{sub ☉}/L{sub ☉}. The NIFS kinematics give a central bulge velocity dispersion σ{sub c} = 116 ± 3 km s{sup –1}, bringing this object slightly closer to the M{sub BH}-σ relation for quiescent galaxies. Although NGC 4151 is one of only a few Seyfert 1 galaxies in which it is possible to obtain a direct dynamical black hole mass measurement—and thus, an independent calibration of the reverberation mapping mass scale—the complex bar kinematics makes it less than ideally suited for this purpose.

  6. Luminous and High Stellar Mass Candidate Galaxies at z ≈ 8 Discovered in the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey

    NASA Astrophysics Data System (ADS)

    Yan, Haojing; Finkelstein, Steven L.; Huang, Kuang-Han; Ryan, Russell E.; Ferguson, Henry C.; Koekemoer, Anton M.; Grogin, Norman A.; Dickinson, Mark; Newman, Jeffrey A.; Somerville, Rachel S.; Davé, Romeel; Faber, S. M.; Papovich, Casey; Guo, Yicheng; Giavalisco, Mauro; Lee, Kyoung-soo; Reddy, Naveen; Cooray, Asantha R.; Siana, Brian D.; Hathi, Nimish P.; Fazio, Giovanni G.; Ashby, Matthew; Weiner, Benjamin J.; Lucas, Ray A.; Dekel, Avishai; Pentericci, Laura; Conselice, Christopher J.; Kocevski, Dale D.; Lai, Kamson

    2012-12-01

    One key goal of the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey is to track galaxy evolution back to z ≈ 8. Its two-tiered "wide and deep" strategy bridges significant gaps in existing near-infrared surveys. Here we report on z ≈ 8 galaxy candidates selected as F105W-band dropouts in one of its deep fields, which covers 50.1 arcmin2 to 4 ks depth in each of three near-infrared bands in the Great Observatories Origins Deep Survey southern field. Two of our candidates have J < 26.2 mag, and are >1 mag brighter than any previously known F105W-dropouts. We derive constraints on the bright end of the rest-frame ultraviolet luminosity function of galaxies at z ≈ 8, and show that the number density of such very bright objects is higher than expected from the previous Schechter luminosity function estimates at this redshift. Another two candidates are securely detected in Spitzer Infrared Array Camera images, which are the first such individual detections at z ≈ 8. Their derived stellar masses are on the order of a few × 109 M ⊙, from which we obtain the first measurement of the high-mass end of the galaxy stellar mass function at z ≈ 8. The high number density of very luminous and very massive galaxies at z ≈ 8, if real, could imply a large stellar-to-halo mass ratio and an efficient conversion of baryons to stars at such an early time.

  7. Near-infrared continuum and 3.3 micrometer(s) polycyclic aromatic hydrocarbon imaging of the starburst ring in the type 1 Seyfert galaxy NGC 7469

    NASA Technical Reports Server (NTRS)

    Mazzarella, J. M.; Voit, G. M.; Soifer, B. T.; Matthews, K.; Graham, J. R.; Armus, L.; Shupe, D.

    1994-01-01

    High resolution near-infrared images of the type 1 Seyfert galaxy NGC 7469 have been obtained to probe its dusty nuclear environment. Direct J, H, and K images are relatively featureless, but residual images created by subtracting a smooth model based on best-fitting elliptical isophotes reveal a tight inner spiral whose high surface-brightness portions correspond to a previously detected 3 sec (1 kpc) diameter ring of radio continuum emission. The inner infrared spiral arms extended approximately equal to 4 sec NW and SE from the nucleus, and the NW arm joins up with large-scale spiral structure visible in the R band. The residual images also show a bar-like structure aligned with the brightest infrared/radio hotspots at PA approximately equal to 50 deg. Three infrared hotspots are detected which align remarkably well with 6 cm radio continuum sources. The near-infrared ring and the hotspots are visible in the residual images, and in a high-resolution direct K-band image restored to an effective resolution of 0.65 sec (FWHM) using the Richardson-Lucy algorithm. The infrared hotspots have luminosities of nuL(sub nu) (2.2 micrometer(s)) approximately equal to 10(exp 8) solar luminosity (M(sub k) approximately equal to -16 mag), suggesting they are either giant H II regions or individual supernovae. The two brightest regions may be associated with enhanced star formation triggered by orbit crowding of gas where spiral arms emerge from an inner bar. Narrowband (delta lambda/lambda approximately 1.5%) imaging in the 3.28 micrometer(s) dust emission feature and surrounding continuum confirms the 3 sec diameter 3.28 micrometer(s) emission region detected previously using multiaperture photometry. The extended polycyclic aromatic hydrocarbon (PAH) emission is slightly elongated and aligned with published 1O III1 line emission and 12.5 micrometer(s) continuum emission, apparently tracing the starburst. The presence of approximately equal to 25% of the total 3.28 micrometer

  8. An early phase of environmental effects on galaxy properties unveiled by near-infrared spectroscopy of protocluster galaxies at z > 2

    NASA Astrophysics Data System (ADS)

    Shimakawa, Rhythm; Kodama, Tadayuki; Tadaki, Ken-ichi; Hayashi, Masao; Koyama, Yusei; Tanaka, Ichi

    2015-03-01

    This work presents the results from our near-infrared spectroscopy of narrow-band-selected Hα emitters (HAEs) in two rich overdensities (PKS 1138-262 at z = 2.2 and USS 1558-003 at z = 2.5) with the Multi-Object Infrared Camera and Spectrograph on the Subaru telescope. These protoclusters are promising candidates for the most massive class of galaxy clusters seen today (Paper I). The confirmed HAEs in the protoclusters at z > 2 show high excitation levels as characterized by much higher [O III]/Hβ or [O III]/Hα line ratios than those of general galaxies at low-z. Such a high excitation level may not only be driven by high specific star formation rates and lower gaseous metallicities, but also be contributed by some other effects. We investigate the environmental dependence of gaseous metallicities by comparing the HAEs in the protoclustrers with those in the general field at similar redshifts. We find that the gaseous metallicities of protocluster galaxies are more chemically enriched than those of field galaxies at a given stellar mass in the range of M⋆ ≲ 1011 M⊙. This can be attributed to many processes, such as intrinsic (or nature) effects, external (or nurture) effects, and/or some systematic sampling effects. The intrinsic (nature) effect leads to the advanced stage of `downsizing' galaxy evolution in protoclusters. On the other hand, the external (nurture) effects include the recycling of chemically enriched gas due to the higher pressure of intergalactic medium and/or stripping of outer gas in the reservoir in protoclusters. We also find that the offset of the mass-metallicity relation in dense environment becomes larger at higher redshifts. This can be naturally understood by the fact that the inflow/outflow rates in star-forming galaxies are much higher at higher redshifts. Therefore, the environmental dependence of such `feeding' and `feedback' mechanisms in galaxy formation is probably playing major roles in producing the offset of the mass

  9. Azadipyrromethene cyclometalation in neutral Ru(II) complexes: photosensitizers with extended near-infrared absorption for solar energy conversion applications.

    PubMed

    Bessette, André; Cibian, Mihaela; Ferreira, Janaina G; DiMarco, Brian N; Bélanger, Francis; Désilets, Denis; Meyer, Gerald J; Hanan, Garry S

    2016-06-28

    In the on-going quest to harvest near-infrared (NIR) photons for energy conversion applications, a novel family of neutral ruthenium(ii) sensitizers has been developed by cyclometalation of an azadipyrromethene chromophore. These rare examples of neutral ruthenium complexes based on polypyridine ligands exhibit an impressive panchromaticity achieved by the cyclometalation strategy, with strong light absorption in the 600-800 nm range that tails beyond 1100 nm in the terpyridine-based adducts. Evaluation of the potential for Dye-Sensitized Solar Cells (DSSC) and Organic Photovoltaic (OPV) applications is made through rationalization of the structure-property relationship by spectroscopic, electrochemical, X-ray structural and computational modelization investigations. Spectroscopic evidence for photo-induced charge injection into the conduction band of TiO2 is also provided. PMID:27264670

  10. NEAR-INFRARED IMAGING OF A z = 6.42 QUASAR HOST GALAXY WITH THE HUBBLE SPACE TELESCOPE WIDE FIELD CAMERA 3

    SciTech Connect

    Mechtley, M.; Windhorst, R. A.; Cohen, S. H.; Jansen, R. A.; Scannapieco, E.; Ryan, R. E.; Koekemoer, A. M.; Schneider, G.; Fan, X.; Hathi, N. P.; Keel, W. C.; Roettgering, H.; Schneider, D. P.; Strauss, M. A.; Yan, H. J.

    2012-09-10

    We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z = 6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous observations of a nearby star of similar near-infrared colors to measure temporal variations in the telescope and instrument point-spread function (PSF). We subtract the quasar point source using both this direct PSF and a model PSF. Using direct subtraction, we measure an upper limit for the quasar host galaxy of m{sub J} > 22.8 and m{sub H} > 23.0 AB mag (2 {sigma}). After subtracting our best model PSF, we measure a limiting surface brightness from 0.''3 to 0.''5 radius of {mu}{sub J} > 23.5 and {mu}{sub H} > 23.7 AB mag arcsec{sup -2} (2 {sigma}). We test the ability of the model subtraction method to recover the host galaxy flux by simulating host galaxies with varying integrated magnitude, effective radius, and Sersic index, and conducting the same analysis. These models indicate that the surface brightness limit ({mu}{sub J} > 23.5 AB mag arcsec{sup -2}) corresponds to an integrated upper limit of m{sub J} > 22-23 AB mag, consistent with the direct subtraction method. Combined with existing far-infrared observations, this gives an infrared excess log (IRX) > 1.0 and corresponding ultraviolet spectral slope {beta} > -1.2 {+-} 0.2. These values match those of most local luminous infrared galaxies, but are redder than those of almost all local star-forming galaxies and z {approx_equal} 6 Lyman break galaxies.

  11. Large Magellanic Cloud Near-infrared Synoptic Survey. II. The Wesenheit Relations and Their Application to the Distance Scale

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Kanbur, Shashi M.; Macri, Lucas M.; Singh, Harinder P.; Ngeow, Chow-Choong; Wagner-Kaiser, R.; Sarajedini, Ata

    2016-04-01

    We present new near-infrared (NIR) Cepheid period-Wesenheit (P-W) relations in the LMC using time-series observations from the Large Magellanic Cloud NIR Synoptic Survey. We also derive optical+NIR P-W relations using V and I magnitudes from the Optical Gravitational Lensing Experiment. We employ our new JHKs data to determine an independent distance to the LMC of {μ }{{LMC}}\\=\\18.47+/- 0.07(statistical) mag, using an absolute calibration of the Galactic relations based on several distance determination methods and accounting for the intrinsic scatter of each technique. We also derive new NIR period-luminosity and Wesenheit relations for Cepheids in M31 using observations from the Panchromatic Hubble Andromeda Treasury survey. We use the absolute calibrations of the Galactic and LMC {W}J,H relations to determine the distance modulus of M31, {μ }{{M31}}\\=\\24.46+/- 0.20 mag. We apply a simultaneous fit to Cepheids in several Local Group galaxies covering a range of metallicities (7.7\\lt 12+{log}[{{O}}/{{H}}]\\lt 8.6 dex) to determine a global slope of -3.244 ± 0.016 mag dex-1 for the {W}J,{Ks} relation and obtain robust distance estimates. Our distances are in good agreement with recent TRGB based distance estimates and we do not find any evidence for a metallicity dependence in the NIR P-W relations.

  12. Novel type-II material system for laser applications in the near-infrared regime

    SciTech Connect

    Berger, C. Möller, C.; Hens, P.; Fuchs, C.; Stolz, W.; Koch, S. W.; Ruiz Perez, A.

    2015-04-15

    The design and experimental realization of a type-II “W”-multiple quantum well heterostructure for emission in the λ > 1.2 μm range is presented. The experimental photoluminescence spectra for different excitation intensities are analyzed using microscopic quantum theory. On the basis of the good theory–experiment agreement, the gain properties of the system are computed using the semiconductor Bloch equations. Gain values comparable to those of type-I systems are obtained.

  13. Optical and near-infrared polarimetric study of the RCW121 Galactic H II region

    NASA Astrophysics Data System (ADS)

    Serón Navarrete, J. C.; Roman-Lopes, A.; Santos, Fabio. P.; Franco, G. A. P.; Reis, W.

    2016-10-01

    We present a polarimetric study of the RCW121 star-forming region to derive the orientation of the sky-projected magnetic field component traced by the polarization vectors, the morphology of which tends to follow the cloud's structure. Individual polarization-angle values are consistent across the different bands, having a broad distribution towards the RCW121 H II region. We estimate the corresponding magnetic field orientation in the H II region to have a mean value of -12° ± 7°. RCW121 shows an elongated shape in the same direction as the magnetic field orientation, which may be evidence that magnetic pressure opposes the H II region expansion. Serkowski's relation was used to determine individual values of the total-to-selective extinction ratio (RV) distribution and a weighted mean value of RV = 3.17 ± 0.05. We derive a foreground component of the polarization degree that is consistent with the literature value for this Galactic region.

  14. Spectroscopic study in the visible and near infrared wavelength of an Hα-selected sample of star-forming galaxies at z = 0.84

    NASA Astrophysics Data System (ADS)

    Sánchez de Miguel, A.; Gallego, J.; Villar, V.; Pérez-González, P. G.; Zamorano, J.; Cardiel, N.; Acosta Pulido, J. A.

    2013-05-01

    In this work we study the physical properties of star-forming galaxies selected in an Hα near-infrared narrow-band survey tuned for redshift z=0.84 (Villar et al. 2008, 2011). Also, we present a sample at z˜1 with mass greater than 10^{10} M_{⊙} with Hα emission. The observations were carried out with WHT/LIRIS (see Sánchez de Miguel et al. 2011, in Highlights of Spanish Astrophysics VI). The rest of the data from the spectra archive of the RAINBOW Cosmological Survey database (Pérez-González et al. 2005, 2008; Barro et al. 2011ab). According to the redshift distribution of these galaxies, 65% of the galaxies are in a redshift range of 0.005. This velocity range corresponds to less than 25% of the effective volume. Which could be indicative of the presence of substructure. A total of 48 galaxies have detected Hα emission and other 12 show [NII]6584. To complete our multi-wavelength sample we found 23 galaxies with Hβ, [OIII]5007 or [OII]3727 detections. Using this photometry from ancillary data we will calculate nebular and stellar extinctions. We have calculated metallicities using the [NII]/Hα ratio and the Pettini & Pagel (2004) calibrations. The metallicity of samples are compatible with the local galaxies. We found that in all the diagnostic diagrams galaxies have similar properties to the local ones, except they are intrinsically brighter for the same equivalent width [OII]3727.

  15. Suppressed blinking and auger recombination in near-infrared type-II InP/CdS nanocrystal quantum dots.

    PubMed

    Dennis, Allison M; Mangum, Benjamin D; Piryatinski, Andrei; Park, Young-Shin; Hannah, Daniel C; Casson, Joanna L; Williams, Darrick J; Schaller, Richard D; Htoon, Han; Hollingsworth, Jennifer A

    2012-11-14

    Nonblinking excitonic emission from near-infrared and type-II nanocrystal quantum dots (NQDs) is reported for the first time. To realize this unusual degree of stability at the single-dot level, novel InP/CdS core/shell NQDs were synthesized for a range of shell thicknesses (~1-11 monolayers of CdS). Ensemble spectroscopy measurements (photoluminescence peak position and radiative lifetimes) and electronic structure calculations established the transition from type-I to type-II band alignment in these heterostructured NQDs. More significantly, single-NQD studies revealed clear evidence for blinking suppression that was not strongly shell-thickness dependent, while photobleaching and biexciton lifetimes trended explicitly with extent of shelling. Specifically, very long biexciton lifetimes-up to >7 ns-were obtained for the thickest-shell structures, indicating dramatic suppression of nonradiative Auger recombination. This new system demonstrates that electronic structure and shell thickness can be employed together to effect control over key single-dot and ensemble NQD photophysical properties.

  16. Strain-balanced Si/SiGe type-II superlattices for near-infrared photodetection

    SciTech Connect

    Ali, Dyan; Richardson, Christopher J. K.

    2014-07-21

    Strain balanced silicon-silicon germanium type-II superlattice p-i-n photodetectors grown on a silicon germanium relaxed buffer layer are shown to exhibit an absorption band that extends beyond 0.7 eV (λ = 1.77 μm) with dark current densities of 27 μA cm{sup −2}. Simulations of the absorption edge, which are based on x-ray diffraction characterization, low observed dark current densities, and low dislocation densities, are consistent with fully strained heterostructures. Potential applications for devices made from this heterostructure design could include integrated silicon detectors, or low-noise absorption regions for infrared-extended silicon based avalanche photodiodes.

  17. Thermal and near-infrared light induced spin crossover in a mononuclear iron(ii) complex with a tetrathiafulvalene-fused dipyridophenazine ligand.

    PubMed

    Pointillart, F; Liu, X; Kepenekian, M; Le Guennic, B; Golhen, S; Dorcet, V; Roisnel, T; Cador, O; You, Z; Hauser, J; Decurtins, S; Ouahab, L; Liu, S-X

    2016-07-28

    A mononuclear Fe(ii) complex involving a tetrathiafulvalene-based ligand exhibits thermal spin-crossover (around 143 K) with pronounced hysteresis behaviour (48 K). The chromophoric and π-extended ligand allows Near-Infrared (NIR) sensitization for the light-induced excited spin-state trapping (LIESST) with T(LIESST) = 90 K. PMID:27358063

  18. The COSMOS-WIRCam Near-Infrared Imaging Survey. I. BzK-Selected Passive and Star-Forming Galaxy Candidates at z gsim 1.4

    NASA Astrophysics Data System (ADS)

    McCracken, H. J.; Capak, P.; Salvato, M.; Aussel, H.; Thompson, D.; Daddi, E.; Sanders, D. B.; Kneib, J.-P.; Willott, C. J.; Mancini, C.; Renzini, A.; Cook, R.; Le Fèvre, O.; Ilbert, O.; Kartaltepe, J.; Koekemoer, A. M.; Mellier, Y.; Murayama, T.; Scoville, N. Z.; Shioya, Y.; Tanaguchi, Y.

    2010-01-01

    We present a new near-infrared survey covering the 2 deg2 COSMOS field conducted using WIRCam at the Canada-France-Hawaii Telescope. By combining our near-infrared data with Subaru B and z images, we construct a deep, wide-field optical-infrared catalog. At K s < 23 (AB magnitudes), our survey completeness is greater than 90% and 70% for stars and galaxies, respectively, and contains 143,466 galaxies and 13,254 stars. Using the BzK diagram, we divide our galaxy catalog into quiescent and star-forming galaxy candidates. At z ~ 2, our catalogs contain 3931 quiescent and 25,757 star-forming galaxies representing the largest and most secure sample at these depths and redshifts to date. Our counts of quiescent galaxies turns over at K s ~ 22, an effect that we demonstrate cannot be due to sample incompleteness. Both the number of faint and bright quiescent objects in our catalogs exceed the predictions of a recent semi-analytic model of galaxy formation, indicating potentially the need for further refinements in the amount of merging and active galactic nucleus feedback at z ~ 2 in these models. We measure the angular correlation function for each sample and find that the slope of the field galaxy correlation function flattens to 1.5 by K s ~ 23. At small angular scales, the angular correlation function for passive BzK galaxies is considerably in excess of the clustering of dark matter. We use precise 30-band photometric redshifts to derive the spatial correlation length and the redshift distributions for each object class. At K s < 22, we find r γ/1.8 0 = 7.0 ± 0.5h -1 Mpc for the passive BzK candidates and 4.7 ± 0.8 h -1 Mpc for the star-forming BzK galaxies. Our pBzK galaxies have an average photometric redshift of zp ~ 1.4, in approximate agreement with the limited spectroscopic information currently available. The stacked K s image will be made publicly available from IRSA. Based on data collected at the Subaru Telescope, which is operated by the National

  19. Hot molecular hydrogen in the central parsec of the Galaxy through near-infrared 3D fitting

    NASA Astrophysics Data System (ADS)

    Ciurlo, A.; Paumard, T.; Rouan, D.; Clénet, Y.

    2016-10-01

    Aims: We have investigated neutral gas in the central cavity of the circumnuclear disk (CND) at the Galactic center, where the ionized minispiral lies, to describe the H2 distribution and properties in this ionized environment. Methods: This study was carried out through a spectro-imaging data cube of the central cavity obtained with SPIFFI on the VLT. The observed field of view is 36″ × 29″, with a spectral resolution R = 1300 in the near-infrared. These observations cover several H2 lines. To preserve the spatial resolution and avoid edge effects, we applied a new line-fitting method that consists of a regularized 3D fitting. We also applied a more classical 1D fitting to compare the relative strength of the H2 lines. Results: We present high spatial and spectral resolution maps of the intensity, velocity, and width of five H2 lines and an extinction map derived from H2. Molecular gas is detected everywhere in the field. In particular, in addition to the known CND features, we detected an emission from the northern arm cloud and from the minicavity. The excitation diagrams allow us to estimate the temperature, mass, and density of these features. Conclusions: We interpret the CND emission as coming from a hot, thermalized, thin layer at the surface of the clouds. The observed H2 corresponds only to a small fraction of the total H2 mass. The emission remains fairly strong in the whole central cavity, but it is not thermalized. A strong deviation from thermal equilibrium is detected near the minicavity. We suggest that this emission is caused by constantly forming H2 that is destroyed again before it reaches ortho/para equilibrium.

  20. A LABOCA SURVEY OF THE EXTENDED CHANDRA DEEP FIELD SOUTH-SUBMILLIMETER PROPERTIES OF NEAR-INFRARED SELECTED GALAXIES

    SciTech Connect

    Greve, T. R.; Walter, F.; Bell, E. F.; Dannerbauer, H.; Rix, H.-W.; Schinnerer, E.; Weiss, A.; Kovacs, A.; Smail, I.; Coppin, K. E. K.; Alexander, D.; Zheng, X. Z.; Knudsen, K. K.; Bertoldi, F.; De Breuck, C.; Dickinson, M.; Gawiser, E.; Lutz, D.; Brandt, N.; Chapman, S. C.

    2010-08-10

    Using the 330 hr ESO-MPG 870 {mu}m survey of the Extended Chandra Deep Field South (ECDF-S) obtained with the Large Apex BOlometer CAmera (LABOCA) on the Atacama Pathfinder EXperiment (APEX), we have carried out a stacking analysis at submillimeter (submm) wavelengths of a sample of 8266 near-infra-red (near-IR) selected (K {sub vega} {<=} 20) galaxies, including 893 BzK galaxies, 1253 extremely red objects (EROs), and 737 distant red galaxies (DRGs), selected from the Multi-wavelength Survey by Yale-Chile (MUSYC). We measure average 870 {mu}m fluxes of 0.22 {+-} 0.01 mJy (22.0{sigma}), 0.48 {+-} 0.04 mJy (12.0{sigma}), 0.39 {+-} 0.03 mJy (13.0{sigma}), and 0.43 {+-} 0.04 mJy (10.8{sigma}) for the K {sub vega} {<=} 20, BzK, ERO, and DRG samples, respectively. For the BzK, ERO, and DRG sub-samples, which overlap to some degree and are likely to be at z {approx_equal} 1-2, this implies an average far-IR luminosity of {approx}(1-5) x 10{sup 11} L{sub sun} and star formation rate (SFR) of {approx}20-90 M{sub sun} . Splitting the BzK galaxies into star-forming (sBzK) and passive (pBzK) galaxies, the former is significantly detected (0.50 {+-} 0.04 mJy, 12.5{sigma}) while the latter is only marginally detected (0.34 {+-} 0.10 mJy, 3.4{sigma}), thus confirming that the sBzK and pBzK criteria to some extent select obscured, star-forming, and truly passive galaxies, respectively. The K {sub vega} {<=} 20 galaxies are found to contribute 7.27 {+-} 0.34 Jy deg{sup -2} (16.5% {+-} 5.7%) to the 870 {mu}m extragalactic background light (EBL). sBzK and pBzK galaxies contribute 1.49 {+-} 0.22 Jy deg{sup -2} (3.4% {+-} 1.3%) and 0.20 {+-} 0.14 Jy deg{sup -2} (0.5% {+-} 0.3%) to the EBL. We present the first delineation of the average submm signal from the K {sub vega} {<=} 20 selected galaxies and their contribution to the submm EBL as a function of (photometric) redshift, and find a decline in the average submm signal (and therefore IR luminosity and SFR) by a factor {approx}2

  1. Near Infrared Observations of a Redshift 5.34 Galaxy: Further Evidence for Significant Dust Absorption in the Early Universe

    NASA Technical Reports Server (NTRS)

    Armus, L.; Matthews, K.; Neugebauer, G.; Soifer, B. T.

    1998-01-01

    In the last several years, the combination of new wavelength dropout discovery techniques coupled with the incredible power of deep imaging of the Hubble Space Telescope and the spectroscopic capabilities of a new generation of large ground-based telescopes, has lead to an astonishing blossoming of the study of galaxies at redshifts of z=2-4, when the Universe was less than 10-20% of its current age.

  2. AN ALMA SURVEY OF SUBMILLIMETER GALAXIES IN THE EXTENDED CHANDRA DEEP FIELD SOUTH: NEAR-INFRARED MORPHOLOGIES AND STELLAR SIZES

    SciTech Connect

    Chen, Chian-Chou; Smail, Ian; Swinbank, A. M.; Simpson, J. M.; Ma, Cheng-Jiun; Alexander, D. M.; Danielson, A. L. R.; Edge, A. C.; Biggs, A. D.; Ivison, R. J.; Brandt, W. N.; Chapman, S. C.; Coppin, K. E. K.; Dannerbauer, H.; Greve, T. R.; Karim, A.; Menten, Karl M.; Schinnerer, E.; Walter, F.; Wardlow, J. L.; and others

    2015-02-01

    We analyze Hubble Space Telescope WFC3/H {sub 160}-band observations of a sample of 48 Atacama Large Millimeter/submillimeter Array detected submillimeter galaxies (SMGs) in the Extended Chandra Deep Field South field, to study their stellar morphologies and sizes. We detect 79% ± 17% of the SMGs in the H {sub 160}-band imaging with a median sensitivity of 27.8 mag, and most (80%) of the nondetections are SMGs with 870 μm fluxes of S {sub 870} < 3 mJy. With a surface brightness limit of μ {sub H} ∼ 26 mag arcsec{sup –2}, we find that 82% ± 9% of the H {sub 160}-band-detected SMGs at z = 1-3 appear to have disturbed morphologies, meaning they are visually classified as either irregulars or interacting systems, or both. By determining a Sérsic fit to the H {sub 160} surface brightness profiles, we derive a median Sérsic index of n = 1.2 ± 0.3 and a median half-light radius of r{sub e} = 4.4{sub −0.5}{sup +1.1} kpc for our SMGs at z = 1-3. We also find significant displacements between the positions of the H {sub 160} component and 870 μm emission in these systems, suggesting that the dusty starburst regions and less-obscured stellar distribution are not colocated. We find significant differences in the sizes and the Sérsic index between our z = 2-3 SMGs and z ∼ 2 quiescent galaxies, suggesting that a major transformation of the stellar light profile is needed in the quenching processes if SMGs are progenitors of the red-and-dead z ∼ 2 galaxies. Given the short-lived nature of SMGs, we postulate that the majority of the z = 2-3 SMGs with S {sub 870} ≳ 2 mJy are early/mid-stage major mergers.

  3. High-Resolution Near-Infrared Spectroscopy of an Equivalent Width-Selected Sample of Starbursting Dwarf Galaxies

    NASA Technical Reports Server (NTRS)

    Maseda, Michael V.; VanDerWeL, Arjen; DaChuna, Elisabete; Rix, Hans-Walter; Pacafichi, Camilla; Momcheva, Ivelina; Brammer, Gabriel B.; Franx, Marijn; VanDokkum, Pieter; Bell, Eric F.; Ferguson, Harry C.; Fumagalli, Mattia; Grogin, Norman A.; Kocevski, Dale D.; Koekemoer, Anton M.; Lundgren, Britt F.; Marchesini, Danilo; Nelson, Erica J.; Patel, Shannon; Skelton, Rosalind E.; Straughn, Amber N.; Trump, Jonathan R.; Weiner, Benjamin J.; Whitaker, Katherine E.; Wuyts, Stijn

    2013-01-01

    Spectroscopic observations from the Large Binocular Telescope and the Very Large Telescope reveal kinematically narrow lines (approx. 50 km/s) for a sample of 14 Extreme Emission Line Galaxies (EELGs) at redshifts 1.4 < zeta < 2.3. These measurements imply that the total dynamical masses of these systems are low ( 3 × 10(exp 9) M). Their large [O III]5007 equivalent widths (500 - 1100 A) and faint blue continuum emission imply young ages of 10-100 Myr and stellar masses of 10(exp 8)-10(exp 9) M, confirming the presence of a violent starburst. The stellar mass formed in this vigorous starburst phase thus represents a large fraction of the total (dynamical) mass, without a significantly massive underlying population of older stars. The occurrence of such intense events in shallow potentials strongly suggests that supernova-driven winds must be of critical importance in the subsequent evolution of these systems.

  4. The near-infrared Ca II triplet as a metallicity indicator - II. Extension to extremely metal-poor metallicity regimes

    NASA Astrophysics Data System (ADS)

    Carrera, R.; Pancino, E.; Gallart, C.; del Pino, A.

    2013-09-01

    We extend our previous calibration of the infrared Ca II triplet (CaT) as a metallicity indicator to the metal-poor regime by including observations of 55 field stars with [Fe/H] down to -4.0 dex. While we previously solved the saturation at high metallicity using a combination of a Lorentzian and a Gaussian to reproduce the line profiles, in this paper we address the non-linearity at low metallicity following the suggestion of Starkenburg et al. of adding two non-linear terms to the relation among the [Fe/H], luminosity and strength of the calcium triplet lines. Our calibration thus extends from -4.0 to +0.5 in metallicity and is presented using four different luminosity indicators: V - VHB, MV, MI and MK. The calibration obtained in this paper results in a tight correlation between [Fe/H] abundances measured from high-resolution spectra and [Fe/H] values derived from the CaT, over the whole metallicity range covered.

  5. K'-band observations of the evil eye galaxy: Are the optical and near-infrared dust albedos identical?

    NASA Technical Reports Server (NTRS)

    Witt, Adolf N.; Lindell, Rebecca S.; Block, David L.; Evans, Rhodri

    1994-01-01

    New measurements of the reduction of the V-band surface brightness across the prominent dust feature in the galaxy NGC 4826 are compared with corresponding increases in the V-K' color within the context of radiative transfer models invoking both absorption and scattering. The K'-band surface brightness is found to be higher than expected from standard dust models. We interpret the difference as resulting from a high effective dust albedo at K', with a likely value in excess of 0.8, provided the near-IR extinction curve in NGC 4826 is identical to the Galactic one. The high effective albedo may result from scattering by dust with a maximum grain size at least twice as large as assumed by standard models, a conclusion already indirectly hinted at by recent studies of dust star-forming regions and reflection nebulae. At least part of the high effective albedo at K' may result from near-IR nonequilibrium continuum emission attributable to very small grains.

  6. A search for Low Surface Brightness galaxies in the near-infrared. III. Nançay H I line observations

    NASA Astrophysics Data System (ADS)

    Monnier Ragaigne, D.; van Driel, W.; Schneider, S. E.; Balkowski, C.; Jarrett, T. H.

    2003-09-01

    A total of 334 Low Surface Brightness galaxies detected in the 2MASS all-sky near-infrared survey have been observed in the 21 cm H I line using the Nançay telescope. All have a Ks-band mean central surface brightness, measured within a 5'' radius, fainter than 18 mag arcsec-2 and a Ks-band isophotal radius at the 20 mag arcsec-2 level larger than 20''. We present global H I line parameters for the 171 clearly detected objects and the 23 marginal detections, as well as upper limits for the undetected objects. The 171 clear detections comprise 50 previously uncatalogued objects and 41 objects with a PGC entry only. Tables 3-5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/408/465 Figures 1 and 2 are only available in electronic form at http://www.edpsciences.org

  7. Infrared Emission of Normal Galaxies from 2.5 to 12 Micron: Infrared Space Observatory Spectra, Near-Infrared Continuum, and Mid-Infrared Emission Features

    NASA Astrophysics Data System (ADS)

    Lu, Nanyao; Helou, George; Werner, Michael W.; Dinerstein, Harriet L.; Dale, Daniel A.; Silbermann, Nancy A.; Malhotra, Sangeeta; Beichman, Charles A.; Jarrett, Thomas H.

    2003-05-01

    We present ISOPHOT spectra of the regions 2.5-4.9 μm and 5.8-11.6 μm for a sample of 45 disk galaxies from the US Infrared Space Observatory Key Project on Normal Galaxies. The galaxies were selected to span the range in global properties of normal, star-forming disk galaxies in the local universe. The spectra can be decomposed into three spectral components: (1) continuum emission from stellar photospheres, which dominates the near-infrared (NIR; 2.5-4.9 μm) spectral region; (2) a weak NIR excess continuum, which has a color temperature of ~103 K, carries a luminosity of a few percent of the total far-infrared (FIR) dust luminosity LFIR and most likely arises from the interstellar medium (ISM); and (3) the well-known broad emission features at 6.2, 7.7, 8.6, and 11.3 μm, which are generally attributed to aromatic carbon particles. These aromatic features in emission (AFEs) dominate the mid-infrared (MIR; 5.8-11.6 μm) part of the spectrum and resemble the so-called type A spectra observed in many nonstellar sources and the diffuse ISM in our own Galaxy. The few notable exceptions include NGC 4418, where a dust continuum replaces the AFEs in MIR, and NGC 1569, where the AFEs are weak and the strongest emission feature is [S IV] 10.51 μm. The relative strengths of the AFEs vary by 15%-25% among the galaxies. However, little correlation is seen between these variations and either IRAS 60 μm/100 μm flux density ratio R(60/100) or the FIR/blue luminosity ratio LFIR/LB, two widely used indicators of the current star formation activity, suggesting that the observed variations are not a consequence of the radiation field differences among the galaxies. We demonstrate that the NIR excess continuum and AFE emission are correlated, suggesting that they are produced by similar mechanisms and similar (or the same) material. On the other hand, as the current star formation activity increases, the overall strengths of the AFEs and the NIR excess continuum drop

  8. Near-Infrared [Fe II] and H2 Line Observations of the Supernova Remnant 3C 396: Probing the Presupernova Circumstellar Materials

    NASA Astrophysics Data System (ADS)

    Lee, Ho-Gyu; Moon, Dae-Sik; Koo, Bon-Chul; Lee, Jae-Joon; Matthews, Keith

    2009-02-01

    We present the results of near-infrared [Fe II] and H2 line imaging and spectroscopic observations of the supernova remnant 3C 396 using the Palomar 5 m Hale telescope. We detect long, filamentary [Fe II] emission delineating the inner edge of the radio emission in the western boundary of the remnant in imaging observations, together with a bright [Fe II] emission clump close to the remnant center. There appears to be faint, diffuse [Fe II] emission between the central clump and the western filamentary emission. The spectroscopic observations determine the expansion velocity of the central clump to be ~56 km s-1. This is far smaller than the expansion velocity of 3C 396 obtained from X-ray observations, implying the inhomogeneity of the ambient medium. The electron number density of the [Fe II] emission gas is <= 2000 cm-3. The H2 line emission, on the other hand, lies slightly outside the filamentary [Fe II] emission in the western boundary, and forms a rather straight filament. We suggest that the [Fe II] emission represents dense clumps in the wind material from the red supergiant phase of a Type IIL/b progenitor of 3C 396, which have been swept up by the supernova remnant shocks. The H2 emission may represent either the boundary of a wind bubble produced during the main-sequence phase of the progenitor or molecular clumps left over inside the bubble. We propose that the near-infrared [Fe II] and H2 emission observed in several supernova remnants of Type IIL/b SNe likely have the same origin.

  9. Selective removal of natural occlusal caries by coupling near-infrared imaging with a CO II laser

    NASA Astrophysics Data System (ADS)

    Tao, You-Chen; Fried, Daniel

    2008-02-01

    Laser removal of dental hard tissue can be combined with optical, spectral or acoustic feedback systems to selectively ablate dental caries and restorative materials. Near-infrared (NIR) imaging has considerable potential for the optical discrimination of sound and demineralized tissue. Last year we successfully demonstrated that near-IR images can be used to guide a CO2 laser ablation system for the selective removal of artificial caries lesions on smooth surfaces. The objective of this study was to test the hypothesis that two-dimensional near-infrared images of natural occlusal caries can be used to guide a CO2 laser for selective removal. Two-dimensional NIR images were acquired at 1310-nm of extracted human molar teeth with occlusal caries. Polarization sensitive optical coherence tomography (PS-OCT) was also used to acquire depth-resolved images of the lesion areas. An imaging processing module was developed to analyze the NIR imaging output and generate optical maps that were used to guide a CO2 laser to selectively remove the lesions at a uniform depth. Post-ablation NIR images were acquired to verify caries removal. Based on the analysis of the NIR images, caries lesions were selectively removed with a CO2 laser while sound tissues were conserved. However, the removal rate varied markedly with the severity of decay and multiple passes were required for caries removal. These initial results are promising but indicate that the selective removal of natural caries is more challenging than the selective removal of artificial lesions due to varying tooth geometry, the highly variable organic/mineral ratio in natural lesions and more complicated lesion structure.

  10. NEAR-INFRARED SURVEY OF THE GOODS-NORTH FIELD: SEARCH FOR LUMINOUS GALAXY CANDIDATES AT z {approx}> 6.5 {sup ,}

    SciTech Connect

    Hathi, Nimish P.; Mobasher, Bahram; Capak, Peter; Wang, Wei-Hao; Ferguson, Henry C.

    2012-09-20

    We present near-infrared (NIR; J and K{sub s}) survey of the Great Observatories Origins Deep Survey-North (GOODS-N) field. The publicly available imaging data were obtained using the MOIRCS instrument on the 8.2 m Subaru and the WIRCam instrument on the 3.6 m Canada-France-Hawaii Telescope (CFHT). These observations fulfill a serious wavelength gap in the GOODS-N data, i.e., lack of deep NIR observations. We combine the Subaru/MOIRCS and CFHT/WIRCam archival data to generate deep J- and K{sub s}-band images, covering the full GOODS-N field ({approx}169 arcmin{sup 2}) to an AB magnitude limit of {approx}25 mag (3{sigma}). We applied z{sub 850}-band dropout color selection criteria, using the NIR data generated here. We have identified two possible Lyman break galaxy (LBG) candidates at z {approx}> 6.5 with J {approx}< 24.5. The first candidate is a likely LBG at z {approx_equal} 6.5 based on a weak spectral feature tentatively identified as Ly{alpha} line in the deep Keck/DEIMOS spectrum, while the second candidate is a possible LBG at z {approx_equal} 7 based on its photometric redshift. These z{sub 850}-dropout objects, if confirmed, are among the brightest such candidates found so far. At z {approx}> 6.5, their star formation rate is estimated as 100-200 M{sub Sun} yr{sup -1}. If they continue to form stars at this rate, they assemble a stellar mass of {approx}5 Multiplication-Sign 10{sup 10} M{sub Sun} after about 400 million years, becoming the progenitors of massive galaxies observed at z {approx_equal} 5. We study the implication of the z{sub 850}-band dropout candidates discovered here, in constraining the bright end of the luminosity function and understanding the nature of high-redshift galaxies.

  11. Near-infrared spectroscopy of 3:1 Kirkwood Gap asteroids II: Probable and plausible parent bodies; primitive and differentiated

    NASA Astrophysics Data System (ADS)

    Fieber-Beyer, Sherry K.; Gaffey, Michael J.

    2014-02-01

    The 3:1 Kirkwood Gap asteroids are a mineralogically diverse set of asteroids located in a region that delivers meteoroids into Earth-crossing orbits. Mineralogical characterizations of asteroids in/near the 3:1 Kirkwood Gap can be used as a tool to “map” conditions and processes in the early Solar System. The chronological studies of the meteorite types provide a “clock” for the relative timing of those events and processes. By identifying the source asteroids of particular meteorite types, the “map” and “clock” can be combined to provide a much more sophisticated understanding of the history and evolution of the late solar nebula and the early Solar System. A mineralogical assessment of twelve 3:1 Kirkwood Gap asteroids has been carried out using near-infrared spectral data obtained from 2010 to 2011 combined with visible spectral data (when available) to cover the spectral interval of 0.4-2.5 μm. Eight of these asteroids have surfaces with basaltic-type silicate assemblages, indicating at least partial melting within their parent bodies. Although HED-like mineralogies are present these objects exhibit subdued features indicating the presence of an additional phase (e.g., NiFe metal) or process (e.g., space weathering). Four of these asteroids appear to be ordinary chondrite assemblages. Three of these are plausibly linked to the probable H-chondrite parent body, (6) Hebe.

  12. The Gas-rich Circumbinary Disk of HR 4049. II. A Detailed Study of the Near-infrared Spectrum

    NASA Astrophysics Data System (ADS)

    Malek, S. E.; Cami, J.

    2014-10-01

    HR 4049 is a peculiar evolved binary surrounded by a circumbinary disk. Mid-infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines originating from the first overtone of CO and from H2O in the 2.3 μm region as well as more complex emission-absorption profiles from H2O and the fundamental mode of CO near 4.6 μm. By using an excitation diagram and from modeling the spectrum, we find that most of the CO overtone and H2O absorption originates from hot gas (T ex ≈ 1000 K) with high column densities, consistent with the mid-infrared data. The strong emission in the wavelength range of the CO fundamental furthermore suggests that there is a significant quantity of gas in the inner cavity of the disk. In addition, there is a much colder component in the line of sight to the disk. A detailed analysis of the overtone line profiles reveals variations in the line widths that are consistent with a radially extended disk in Keplerian rotation with hotter gas closer to the central star. We estimate the mass of the primary to be ~0.34 M ⊙ and discuss the implications for its evolutionary status.

  13. GROUND-BASED, NEAR-INFRARED EXOSPECTROSCOPY. II. TENTATIVE DETECTION OF EMISSION FROM THE EXTREMELY HOT JUPITER WASP-12b

    SciTech Connect

    Crossfield, Ian J. M.; Hansen, Brad M. S.; Barman, Travis

    2012-02-10

    We report the tentative detection of the near-infrared emission of the hot Jupiter WASP-12b with the low-resolution prism on Infrared Telescope Facility/SpeX. We find a K - H contrast color of 0.137% {+-} 0.054%, corresponding to a blackbody of temperature 2400{sup +1500}{sub -500} K and consistent with previous, photometric observations. We also revisit WASP-12b's energy budget on the basis of secondary eclipse observations: the dayside luminosity is a relatively poorly constrained (2.0-4.3) Multiplication-Sign 10{sup 30} erg s{sup -1}, but this still allows us to predict a day/night effective temperature contrast of 200-1000 K (assuming A{sub B} = 0). Thus, we conclude that WASP-12b probably does not have both a low albedo and low recirculation efficiency. Our results show the promise and pitfalls of using single-slit spectrographs for characterization of extrasolar planet atmospheres, and we suggest future observing techniques and instruments which could lead to further progress. Limiting systematic effects include the use of too narrow a slit on one night-which observers could avoid in the future-and chromatic slit losses (resulting from the variable size of the seeing disk) and variations in telluric transparency-which observers cannot control. Single-slit observations of the type we present remain the best option for obtaining {lambda} > 1.7 {mu}m spectra of transiting exoplanets in the brightest systems. Further and more precise spectroscopy is needed to better understand the atmospheric chemistry, structure, and energetics of this, and other, intensely irradiated planet.

  14. Investigating the Near-Infrared Properties of Planetary Nebulae II. Medium Resolution Spectra. 2; Medium Resolution Spectra

    NASA Technical Reports Server (NTRS)

    Hora, Joseph L.; Latter, William B.; Deutsch, Lynne K.

    1998-01-01

    We present medium-resolution (R approximately 700) near-infrared (lambda = 1 - 2.5 micrometers) spectra of a sample of planetary nebulae (PNe). A narrow slit was used which sampled discrete locations within the nebulae; observations were obtained at one or more positions in the 41 objects included in the survey. The PN spectra fall into one of four general categories: H1 emission line-dominated PNe, H1 and H2 emission line PNe, H2 emission line-dominated PNe, and continuum-dominated PNe. These categories correlate with morphological type, with the elliptical PNe falling into the first group, and the bipolar PNe primarily in the H2 and continuum emission groups. The categories also correlate with C/O ratio, with the O-rich objects falling into the first group and the C-rich objects in the groups. Other spectral features were observed in all catagories, such as continuum emission from the central star, and warm dust continuum emission towards the long wavelength end of the spectra. H2 was detected in four PNe in this survey for the first time. An analysis was performed using the H2 line ratios in all of the PN spectra in the survey where a sufficient number of lines were observed to determine the ortho-to-para ratio and the rotational and vibrational excitation temperatures of the H-2 in those objects. One unexpected result from this analysis is that the H-2 is excited by absorption of ultraviolet photons in most of the PNe, although there are several PNe in which collisional excitation plays an important role. The correlation between bipolar morphology and H2 emission has been strengthened with the new detections of H2 in this survey.

  15. The gas-rich circumbinary disk of HR 4049. II. A detailed study of the near-infrared spectrum

    SciTech Connect

    Malek, S. E.; Cami, J. E-mail: jcami@uwo.ca

    2014-10-20

    HR 4049 is a peculiar evolved binary surrounded by a circumbinary disk. Mid-infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines originating from the first overtone of CO and from H{sub 2}O in the 2.3 μm region as well as more complex emission-absorption profiles from H{sub 2}O and the fundamental mode of CO near 4.6 μm. By using an excitation diagram and from modeling the spectrum, we find that most of the CO overtone and H{sub 2}O absorption originates from hot gas (T {sub ex} ≈ 1000 K) with high column densities, consistent with the mid-infrared data. The strong emission in the wavelength range of the CO fundamental furthermore suggests that there is a significant quantity of gas in the inner cavity of the disk. In addition, there is a much colder component in the line of sight to the disk. A detailed analysis of the overtone line profiles reveals variations in the line widths that are consistent with a radially extended disk in Keplerian rotation with hotter gas closer to the central star. We estimate the mass of the primary to be ∼0.34 M {sub ☉} and discuss the implications for its evolutionary status.

  16. Near-Infrared Properties of Moderate-Redshift Galaxy Clusters: Halo Occupation Number, Mass-to-Light Ratios and Omega(M)

    SciTech Connect

    Muzzin, Adam; Yee, H.K.C.; Hall, Patrick B.; Lin, Huan; /Fermilab

    2007-03-01

    Using K-band imaging for 15 of the Canadian Network for Observational Cosmology (CNOC1) clusters we examine the near-infrared properties of moderate-redshift (0.19 < z < 0.55) galaxy clusters. We find that the number of K-band selected cluster galaxies within R{sub 500} (the Halo Occupation Number, HON) is well-correlated with the cluster dynamical mass (M{sub 500}) and X-ray Temperature (T{sub x}); however, the intrinsic scatter in these scaling relations is 37% and 46% respectively. Comparison with clusters in the local universe shows that the HON-M{sub 500} relation does not evolve significantly between z = 0 and z {approx} 0.3. This suggests that if dark matter halos are disrupted or undergo significant tidal-stripping in high-density regions as seen in numerical simulations, the stellar mass within the halos is tightly bound, and not removed during the process. The total K-band cluster light (L{sub 200},K) and K-band selected richness (parameterized by B{sub gc,K}) are also correlated with both the cluster T{sub x} and M{sub 200}. The total (intrinsic) scatter in the L{sub 200,K}-M{sub 200} and B{sub gc,K}-M{sub 200} relations are 43%(31%) and 35%(18%) respectively and indicates that for massive clusters both L{sub 200,K} and B{sub gc,K} can predict M{sub 200} with similar accuracy as T{sub x}, L{sub x} or optical richness (B{sub gc}). Examination of the mass-to-light ratios of the clusters shows that similar to local clusters, the K-band mass-to-light ratio is an increasing function of halo mass. Using the K-band mass-to-light ratios of the clusters, we apply the Oort technique and find {Omega}{sub m,0} = 0.22 {+-} 0.02, which agrees well with recent combined concordance cosmology parameters, but, similar to previous cluster studies, is on the low-density end of preferred values.

  17. Near-infrared spectroscopy of M dwarfs. II. H2O molecule as an abundance indicator of oxygen†

    NASA Astrophysics Data System (ADS)

    Tsuji, Takashi; Nakajima, Tadashi; Takeda, Yoichi

    2015-04-01

    Based on the near-infrared spectra (R ≈ 20000) of M dwarfs, oxygen abundances are determined from the rovibrational lines of H2O. Although H2O lines in M dwarfs are badly blended with each other and the continuum levels are depressed appreciably by the collective effect of the numerous H2O lines themselves, quantitative analysis of H2O lines has been carried out by referring to the pseudo-continua, consistently defined on the observed and theoretical spectra. For this purpose, the pseudo-continuum on the theoretical spectrum has been evaluated accurately by the use of the recent high-precision H2O line-list. Then, we propose a simple and flexible method of analyzing the equivalent widths (EWs) of blended features (i.e., not necessarily limited to single lines) by the use of a mini-curve-of-growth (CG), which is a small portion of the usual CG around the observed EW. The mini-CG is generated by using the theoretical EWs evaluated from the synthetic spectrum in exactly the same way as the EWs are measured from the observed spectrum. The observed EW is converted to the abundance by the use of the mini-CG, and the process is repeated for all the observed EWs line-by-line or blend-by-blend. In cool M dwarfs, almost all the oxygen atoms left after CO formation are in stable H2O molecules, which suffer little change for the uncertainties due to imperfect modelling of the photospheres. Thus the numerous H2O lines are excellent abundance indicators of oxygen. The oxygen abundances are determined to be log AO (AO = NO/NH) between -3.5 and -3.0 in 38 M dwarfs, but cannot be determined in four early M dwarfs in which H2O lines are detected only marginally. The resulting log AO/AC values plotted against log AC appear to be systematically smaller in the carbon-rich M dwarfs, showing the different formation histories of oxygen and carbon in the chemical evolution of the Galactic disk. Also, AO/AFe ratios in most M dwarfs are closer to the solar AO/AFe ratio, based on the

  18. Spider. IV. Optical and Near-infrared Color Gradients in Early-type Galaxies: New Insight into Correlations with Galaxy Properties

    NASA Astrophysics Data System (ADS)

    La Barbera, F.; De Carvalho, R. R.; De La Rosa, I. G.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

    2010-11-01

    We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, ∇sstarf, which incorporates all of the available color indices, we investigate how ∇sstarf varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M sstarf) and dynamical (M dyn) masses, as well as age, metallicity, and [α/Fe]. ETGs with M dyn larger than 8.5 × 1010 M sun have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [α/Fe] are the main drivers of these correlations. ETGs with 2.5 × 1010 M sun <= M dyn <= 8.5 × 1010 M sun show no correlation of age, metallicity, and color gradients with respect to mass, although color gradients still correlate with stellar population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and α-enhancement is significant at ~5σ and results from the fact that metallicity gradient decreases with [α/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than ~5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

  19. SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES

    SciTech Connect

    La Barbera, F.; De Carvalho, R. R.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

    2010-11-15

    We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, {nabla}{sub *}, which incorporates all of the available color indices, we investigate how {nabla}{sub *} varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M{sub *}) and dynamical (M{sub dyn}) masses, as well as age, metallicity, and [{alpha}/Fe]. ETGs with M{sub dyn} larger than 8.5 x 10{sup 10} M{sub sun} have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [{alpha}/Fe] are the main drivers of these correlations. ETGs with 2.5 x 10{sup 10} M{sub sun} {<=} M{sub dyn} {<=} 8.5 x 10{sup 10} M{sub sun} show no correlation of age, metallicity, and color gradients with respect to mass, although color gradients still correlate with stellar population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and {alpha}-enhancement is significant at {approx}5{sigma} and results from the fact that metallicity gradient decreases with [{alpha}/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than {approx}5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

  20. THE HIGH A{sub V} Quasar Survey: Reddened Quasi-Stellar Objects selected from optical/near-infrared photometry. II

    SciTech Connect

    Krogager, J.-K.; Fynbo, J. P. U.; Vestergaard, M.; Geier, S.; Venemans, B. P.; Ledoux, C.; Møller, P.; Noterdaeme, P.; Kangas, T.; Pursimo, T.; Smirnova, O.; Saturni, F. G.

    2015-03-15

    Quasi-stellar objects (QSOs) whose spectral energy distributions (SEDs) are reddened by dust either in their host galaxies or in intervening absorber galaxies are to a large degree missed by optical color selection criteria like the ones used by the Sloan Digital Sky Survey (SDSS). To overcome this bias against red QSOs, we employ a combined optical and near-infrared (near-IR) color selection. In this paper, we present a spectroscopic follow-up campaign of a sample of red candidate QSOs which were selected from the SDSS and the UKIRT Infrared Deep Sky Survey (UKIDSS). The spectroscopic data and SDSS/UKIDSS photometry are supplemented by mid-infrared photometry from the Wide-field Infrared Survey Explorer. In our sample of 159 candidates, 154 (97%) are confirmed to be QSOs. We use a statistical algorithm to identify sightlines with plausible intervening absorption systems and identify nine such cases assuming dust in the absorber similar to Large Magellanic Cloud sightlines. We find absorption systems toward 30 QSOs, 2 of which are consistent with the best-fit absorber redshift from the statistical modeling. Furthermore, we observe a broad range in SED properties of the QSOs as probed by the rest-frame 2 μm flux. We find QSOs with a strong excess as well as QSOs with a large deficit at rest-frame 2 μm relative to a QSO template. Potential solutions to these discrepancies are discussed. Overall, our study demonstrates the high efficiency of the optical/near-IR selection of red QSOs.

  1. Near-Infrared Sentinel Lymph Node Mapping With Indocyanine Green Using the VITOM II ICG Exoscope for Open Surgery for Gynecologic Malignancies.

    PubMed

    Buda, Alessandro; Dell'Anna, Tiziana; Vecchione, Francesca; Verri, Debora; Di Martino, Giampaolo; Milani, Rodolfo

    2016-01-01

    Sentinel lymph node (SLN) mapping is emerging as an effective method for surgical staging of different gynecologic malignancies. Near-infrared (NIR) technology using a fluorescent dye such as indocyanine green (ICG) represents an interesting and feasible method for SLN mapping even in traditional open surgeries by applying video telescope operating microscope (VITOM) system technology. We report our preliminary experience in 12 women who underwent surgical nodal staging for early-stage vulvar and uterine or cervical cancer. Surgical and pathological outcomes are described, and the VITOM II ICG system's intraoperative image quality, handling and docking, and teaching value are assessed. The general impression of the surgical staff was that the VITOM II system is easy to use, and that the image quality of the anatomic structures is impressive. Traditional open SLN mapping with ICG appears to be easy to perform and reproducible, providing a new tool in the management of patients with gynecologic malignancies. Moreover, we believe that this technology has great potential as an operative teaching and learning modality for trainers for open surgical cases. Additional studies involving the VITOM system with a large sample size of patients are needed to confirm these promising results. PMID:26921484

  2. The SafeBoosC II randomized trial: treatment guided by near-infrared spectroscopy reduces cerebral hypoxia without changing early biomarkers of brain injury

    PubMed Central

    Plomgaard, Anne M.; van Oeveren, Wim; Petersen, Tue H.; Alderliesten, Thomas; Austin, Topun; van Bel, Frank; Benders, Manon; Claris, Olivier; Dempsey, Eugene; Franz, Axel; Fumagalli, Monica; Gluud, Christian; Hagmann, Cornelia; Hyttel-Sorensen, Simon; Lemmers, Petra; Pellicer, Adelina; Pichler, Gerhard; Winkel, Per; Greisen, Gorm

    2016-01-01

    Background: The SafeBoosC phase II multicentre randomized clinical trial investigated the benefits and harms of monitoring cerebral oxygenation by near-infrared spectroscopy (NIRS) combined with an evidence-based treatment guideline vs. no NIRS data and treatment as usual in the control group during the first 72 h of life. The trial demonstrated a significant reduction in the burden of cerebral hypoxia in the experimental group. We now report the blindly assessed and analyzed treatment effects on electroencephalographic (EEG) outcomes (burst rate and spectral edge frequency 95% (SEF95)) and blood biomarkers of brain injury (S100β, brain fatty acid-binding protein, and neuroketal). Methods: One hundred and sixty-six extremely preterm infants were randomized to either experimental or control group. EEG was recorded at 64 h of age and blood samples were collected at 6 and 64 h of age. Results: One hundred and thirty-three EEGs were evaluated. The two groups did not differ regarding burst rates (experimental 7.2 vs. control 7.7 burst/min) or SEF95 (experimental 18.1 vs. control 18.0 Hz). The two groups did not differ regarding blood S100β, brain fatty acid-binding protein, and neuroketal concentrations at 6 and 64 h (n = 123 participants). Conclusion: Treatment guided by NIRS reduced the cerebral burden of hypoxia without affecting EEG or the selected blood biomarkers. PMID:26679155

  3. Dissymmetric Bis(dipyrrinato)zinc(II) Complexes: Rich Variety and Bright Red to Near-Infrared Luminescence with a Large Pseudo-Stokes Shift.

    PubMed

    Sakamoto, Ryota; Iwashima, Toshiki; Kögel, Julius F; Kusaka, Shinpei; Tsuchiya, Mizuho; Kitagawa, Yasutaka; Nishihara, Hiroshi

    2016-05-01

    Bis(dipyrrinato)metal(II) and tris(dipyrrinato)metal(III) complexes have been regarded as much less useful luminophores than their boron difluoride counterparts (4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes, BODIPYs), especially in polar solvent. We proposed previously that dissymmetry in such metal complexes (i.e., two different dipyrrinato ligands in one molecule) improves their fluorescence quantum efficiencies. In this work, we demonstrate the universality and utility of our methodology by synthesizing eight new dissymmetric bis(dipyrrinato)zinc(II) complexes and comparing them with corresponding symmetric complexes. Single-crystal X-ray diffraction analysis, (1)H and (13)C NMR spectroscopy, and high-resolution mass spectrometry confirm the retention of dissymmetry in both solution and solid states. The dissymmetric complexes all show greater photoluminescence (PL) quantum yields (ϕPL) than the corresponding symmetric complexes, allowing red to near-infrared emissions with large pseudo-Stokes shifts. The best performance achieves a maximum PL wavelength of 671 nm, a pseudo-Stokes shift of 5400 cm(-1), and ϕPL of 0.62-0.72 in toluene (dielectric constant εs = 2.4), dichloromethane (εs = 9.1), acetone (εs = 21.4), and ethanol (εs = 24.3). The large pseudo-Stokes shift is distinctive considering BODIPYs with small Stokes shifts (∼500 cm(-1)), and the ϕPL values are higher than or comparable to those of BODIPYs fluorescing at similar wavelengths. Electrochemistry and density functional theory calculations illustrate that frontier orbital ordering in the dissymmetric complexes meets the condition for efficient PL proposed in our theory.

  4. 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.

  5. HST/WFC3 Near-Infrared Spectroscopy of Quenched and Mildly Star Forming Galaxies at 1.4 from WISPs: Stellar Population Properties

    NASA Astrophysics Data System (ADS)

    Bedregal, Alejandro; Scarlata, C.; WISP Survey Team

    2013-01-01

    We combine HST G102 and G141 near-IR grism spectroscopy with HST/UVIS, HST/WFC3 and Spitzer/IRAC[3.6 micron] photometry to assemble a sample of massive (M_star/M_sun = 11.0 dex) and rather passive galaxies at 1.4. After restricting to masses above 10.65 dex, this sample of 80 sources is the largest with homogeneous near-IR spectroscopy for this kind of galaxies at these redshifts. In contrast to the local Universe, we find the mass range above 10.65 dex is populated by galaxies with a wide range of properties. Although our color selection excludes from the sample typical SF massive galaxies, we still find two populations characterized by distinctive average luminosity-weighted ages and star-formation time-scales, but having similar mass and redshift distributions. The spectral energy distributions of Quenched galaxies (SSFR=<10^-2Gyr^-1) are well fitted with exponentially decreasing SFHs, and short star-formation timescales (tau=10-100Myr). They also show a wide distribution in ages, between 1 and 3 Gyrs. On the other hand, we also find a population of low SSFR galaxies (SSFR >10^-2Gyr.^-1) which show more extended SFHs (tau=0.1-1Gyr), being mostly old 3Gyr), and with higher A_V extinctions than the quenched galaxies. Given the stellar mass range covered by our SF galaxies, we find that their SFRs are low compared to normal SF galaxies at these redshifts (median SF 7M_sun yr^-1). We find that the old and massive population of mild-SF galaxies has properties inconsistent with them being a rejuvenated version of the quenched population at the same redshift. This possibly implies that the two samples originate from different mechanisms. In particular, the stellar-population properties of the quenched galaxies are consistent with being the result of gas-rich major mergers, well before the epoch of observation, and with a quick truncation of the SF after the merger. Instead, the properties of the old and mild-SF galaxies are in better agreement with a more extended

  6. A PARAMETERIZED GALAXY CATALOG SIMULATOR FOR TESTING CLUSTER FINDING, MASS ESTIMATION, AND PHOTOMETRIC REDSHIFT ESTIMATION IN OPTICAL AND NEAR-INFRARED SURVEYS

    SciTech Connect

    Song, Jeeseon; Mohr, Joseph J.; Barkhouse, Wayne A.; Rude, Cody; Warren, Michael S.; Dolag, Klaus

    2012-03-01

    We present a galaxy catalog simulator that converts N-body simulations with halo and subhalo catalogs into mock, multiband photometric catalogs. The simulator assigns galaxy properties to each subhalo in a way that reproduces the observed cluster galaxy halo occupation distribution, the radial and mass-dependent variation in fractions of blue galaxies, the luminosity functions in the cluster and the field, and the color-magnitude relation in clusters. Moreover, the evolution of these parameters is tuned to match existing observational constraints. Parameterizing an ensemble of cluster galaxy properties enables us to create mock catalogs with variations in those properties, which in turn allows us to quantify the sensitivity of cluster finding to current observational uncertainties in these properties. Field galaxies are sampled from existing multiband photometric surveys of similar depth. We present an application of the catalog simulator to characterize the selection function and contamination of a galaxy cluster finder that utilizes the cluster red sequence together with galaxy clustering on the sky. We estimate systematic uncertainties in the selection to be at the {<=}15% level with current observational constraints on cluster galaxy populations and their evolution. We find the contamination in this cluster finder to be {approx}35% to redshift z {approx} 0.6. In addition, we use the mock galaxy catalogs to test the optical mass indicator B{sub gc} and a red-sequence redshift estimator. We measure the intrinsic scatter of the B{sub gc}-mass relation to be approximately log normal with {sigma}{sub log10M}{approx}0.25 and we demonstrate photometric redshift accuracies for massive clusters at the {approx}3% level out to z {approx} 0.7.

  7. USING THE 1.6 {mu}m BUMP TO STUDY REST-FRAME NEAR-INFRARED-SELECTED GALAXIES AT REDSHIFT 2

    SciTech Connect

    Sorba, Robert; Sawicki, Marcin

    2010-10-01

    We explore the feasibility and limitations of using the 1.6 {mu}m bump as a photometric redshift indicator and selection technique, and use it to study the rest-frame H-band galaxy luminosity and stellar mass functions (SMFs) at redshift z {approx} 2. We use publicly available Spitzer/IRAC images in the GOODS fields and find that color selection in the IRAC bandpasses alone is comparable in completeness and contamination to BzK selection. We find that the shape of the 1.6 {mu}m bump is robust, and photometric redshifts are not greatly affected by choice of model parameters. Comparison with spectroscopic redshifts shows photometric redshifts to be reliable. We create a rest-frame NIR-selected catalog of galaxies at z {approx} 2 and construct a galaxy SMF. Comparisons with other SMFs at approximately the same redshift but determined using shorter wavelengths show good agreement. This agreement suggests that selection at bluer wavelengths does not miss a significant amount of stellar mass in passive galaxies. Comparison with SMFs at other redshifts shows evidence for the downsizing scenario of galaxy evolution. We conclude by pointing out the potential for using the 1.6 {mu}m bump technique to select high-redshift galaxies with the JWST, whose {lambda}>0.6 {mu}m coverage will not be well suited to selecting galaxies using techniques that require imaging at shorter wavelengths.

  8. HST/WFC3 Near-infrared Spectroscopy of Quenched Galaxies at z ~ 1.5 from the WISP Survey: Stellar Population Properties

    NASA Astrophysics Data System (ADS)

    Bedregal, A. G.; Scarlata, C.; Henry, A. L.; Atek, H.; Rafelski, M.; Teplitz, H. I.; Dominguez, A.; Siana, B.; Colbert, J. W.; Malkan, M.; Ross, N. R.; Martin, C. L.; Dressler, A.; Bridge, C.; Hathi, N. P.; Masters, D.; McCarthy, P. J.; Rutkowski, M. J.

    2013-12-01

    We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3-UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 μm] photometry to assemble a sample of massive (log (M star/M ⊙) ~ 11.0) and quenched (specific star formation rate <0.01 Gyr-1) galaxies at z ~ 1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy for quenched sources at these redshifts. In contrast to the local universe, z ~ 1.5 quenched galaxies in the high-mass range have a wide range of stellar population properties. We find that their spectral energy distributions (SEDs) are well fitted with exponentially decreasing star formation histories and short star formation timescales (τ <= 100 Myr). Quenched galaxies also show a wide distribution in ages, between 1 and 4 Gyr. In the (u - r)0-versus-mass space quenched galaxies have a large spread in rest-frame color at a given mass. Most quenched galaxies populate the z ~ 1.5 red sequence (RS), but an important fraction of them (32%) have substantially bluer colors. Although with a large spread, we find that the quenched galaxies on the RS have older median ages (3.1 Gyr) than the quenched galaxies off the RS (1.5 Gyr). We also show that a rejuvenated SED cannot reproduce the observed stacked spectra of (the bluer) quenched galaxies off the RS. We derive the upper limit on the fraction of massive galaxies on the RS at z ~ 1.5 to be <43%. We speculate that the young quenched galaxies off the RS are in a transition phase between vigorous star formation at z > 2 and the z ~ 1.5 RS. According to their estimated ages, the time required for quenched galaxies off the RS to join their counterparts on the z ~ 1.5 RS is of the order of ~1 Gyr. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.

  9. HST/WFC3 near-infrared spectroscopy of quenched galaxies at z ∼ 1.5 from the WISP survey: Stellar population properties

    SciTech Connect

    Bedregal, A. G.; Scarlata, C.; Rutkowski, M. J.; Henry, A. L.; Martin, C. L.; Atek, H.; Colbert, J. W.; Rafelski, M.; Teplitz, H. I.; Dominguez, A.; Siana, B.; Masters, D.; Malkan, M.; Ross, N. R.; Dressler, A.; Bridge, C.; Hathi, N. P.; McCarthy, P. J.

    2013-12-01

    We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3-UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 μm] photometry to assemble a sample of massive (log (M {sub star}/M {sub ☉}) ∼ 11.0) and quenched (specific star formation rate <0.01 Gyr{sup –1}) galaxies at z ∼ 1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy for quenched sources at these redshifts. In contrast to the local universe, z ∼ 1.5 quenched galaxies in the high-mass range have a wide range of stellar population properties. We find that their spectral energy distributions (SEDs) are well fitted with exponentially decreasing star formation histories and short star formation timescales (τ ≤ 100 Myr). Quenched galaxies also show a wide distribution in ages, between 1 and 4 Gyr. In the (u – r){sub 0}-versus-mass space quenched galaxies have a large spread in rest-frame color at a given mass. Most quenched galaxies populate the z ∼ 1.5 red sequence (RS), but an important fraction of them (32%) have substantially bluer colors. Although with a large spread, we find that the quenched galaxies on the RS have older median ages (3.1 Gyr) than the quenched galaxies off the RS (1.5 Gyr). We also show that a rejuvenated SED cannot reproduce the observed stacked spectra of (the bluer) quenched galaxies off the RS. We derive the upper limit on the fraction of massive galaxies on the RS at z ∼ 1.5 to be <43%. We speculate that the young quenched galaxies off the RS are in a transition phase between vigorous star formation at z > 2 and the z ∼ 1.5 RS. According to their estimated ages, the time required for quenched galaxies off the RS to join their counterparts on the z ∼ 1.5 RS is of the order of ∼1 Gyr.

  10. HST-WFC3 Near-Infrared Spectroscopy of Quenched Galaxies at zeta approx 1.5 from the WISP Survey: Stellar Populations Properties

    NASA Technical Reports Server (NTRS)

    Bedregal, A. G.; Scarlata, C.; Henry, A. L.; Atek, H.; Rafelski, M.; Teplitz, H. I.; Dominguez, A.; Siana, B.; Colbert, J. W.; Malkan, M.; Ross, N. R.; Martin, C. L.; Dressler, A.; Bridge, C.; Hathi, N. P.; Masters, D.; McCarthy, P. J.; Rutkowski, M. J.

    2013-01-01

    We combine Hubble Space Telescope (HST) G102 and G141 near-IR (NIR) grism spectroscopy with HST/WFC3- UVIS, HST/WFC3-IR, and Spitzer/IRAC [3.6 microns] photometry to assemble a sample of massive (log(Mstar/M solar mass) at approx 11.0) and quenched (specific star formation rate < 0.01 G/yr(exp -1) galaxies at zeta approx 1.5. Our sample of 41 galaxies is the largest with G102+G141 NIR spectroscopy for quenched sources at these redshifts. In contrast to the local universe, zeta approx 1.5 quenched galaxies in the high-mass range have a wide range of stellar population properties. We find that their spectral energy distributions (SEDs) are well fitted with exponentially decreasing star formation histories and short star formation timescales (tau less than or equal to 100 M/yr). Quenched galaxies also show a wide distribution in ages, between 1 and 4 G/yr. In the (u - r)0-versus-mass space quenched galaxies have a large spread in rest-frame color at a given mass. Most quenched galaxies populate the zeta appro. 1.5 red sequence (RS), but an important fraction of them (32%) have substantially bluer colors. Although with a large spread, we find that the quenched galaxies on the RS have older median ages (3.1 G/yr) than the quenched galaxies off the RS (1.5 G/yr). We also show that a rejuvenated SED cannot reproduce the observed stacked spectra of (the bluer) quenched galaxies off the RS. We derive the upper limit on the fraction of massive galaxies on the RS at zeta approx 1.5 to be <43%.We speculate that the young quenched galaxies off the RS are in a transition phase between vigorous star formation at zeta > 2 and the zeta approx 1.5 RS. According to their estimated ages, the time required for quenched galaxies off the RS to join their counterparts on the z approx. 1.5 RS is of the order of approx. 1G/yr.

  11. Near-Infrared Spectroscopy of Two Galaxies at z=2.3 and z=2.9: New Probes of Chemical and Dynamical Evolution at High Redshift

    NASA Astrophysics Data System (ADS)

    Kobulnicky, Henry A.; Koo, David C.

    2000-12-01

    This study presents Keck optical and infrared spectroscopy of the rest-frame ultraviolet and optical emission lines in two Lyα-emitting galaxies at z>2. These data provide insight on the evolution of fundamental galaxy scaling relations at early epochs, especially the luminosity-velocity and luminosity-metallicity relations. Spectral diagnostics suggest that the Coup Fourré galaxy at z=2.3 and Lynx 2-9691, a serendipitously discovered, luminous Lyman drop galaxy at z=2.9, are star-forming galaxies without active nuclei. Lynx 2-9691 exhibits extended [O III] emission over a diameter of greater than 28 kpc, reminiscent of the Lyα nebulae discovered near Lyman drop galaxies. We estimate star formation rates of 59 and 111 Msolar yr-1, respectively, from Balmer recombination line luminosities, 2-3 times higher than inferred from the ultraviolet continuum. The ratios of strong nebular emission lines indicate subsolar oxygen abundances in the range 8.2<12+log(O/H)<8.8 (Z=0.25-0.95 Zsolar). Interestingly, Galactic metal-rich globular clusters have similar metallicities, consistent with the idea that we could be seeing the formation of galaxies like the Milky Way at z~3. The measured gas-phase oxygen abundances are greater than 4-10 times higher than the Z<0.1 Zsolar metallicities found in damped Lyα (DLA) absorbers at similar redshifts, indicating that DLA systems trace fundamentally different environments than the vigorously star-forming objects observed here. If this intense star formation activity represents the dominant formation episodes for stars in today's spiral bulges or ellipticals, then the evolved descendants in the local universe should exhibit similarly subsolar metallicities in their dominant stellar populations that formed 8-10 Gyr ago. When these new data are combined with a sample of four other high-redshift spectroscopic results from the literature, we find that star-forming galaxies at z~3 are 2-4 mag more luminous than local spiral galaxies of

  12. A New Synthetic Library of the Near-infrared Ca II Triplet Indices. I. Index Definition, Calibration, and Relations with Stellar Atmospheric Parameters

    NASA Astrophysics Data System (ADS)

    Du, W.; Luo, A. L.; Zhao, Y. H.

    2012-02-01

    Adopting the SPECTRUM package, which is a stellar spectral synthesis program, we have synthesized a comprehensive set of 2890 near-infrared (NIR) synthetic spectra with a resolution and wavelength sampling similar to the Sloan Digital Sky Survey (SDSS) and the forthcoming Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. During the synthesis, we applied the "New grids of ATLAS9 Model Atmosphere" to develop a grid of local thermodynamic equilibrium model atmospheres for effective temperatures (T eff) ranging from 3500 to 7500 K, for surface gravities (log g) from 0.5 to 5.0 dex, for metallicities ([Fe/H]) from -4.0 to 0.5 dex, and for solar ([α/Fe] = 0.0 dex) and non-solar ([α/Fe] = +0.4 dex) abundances. This synthetic stellar library is composed of 1350 solar scaled abundance (SSA) and 1530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR Ca II triplet indices and an index CaT as the sum of the three. These defined indices were automatically measured on every spectrum of the synthetic stellar library and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of α-element enhancement on the so-defined Ca II indices, we compared indices measured on the SSA spectra with those on the NSSA ones at the same trine of stellar parameters (T eff, log g, [Fe/H]); luckily, little influences of α-element enhancement were found. Furthermore, comparisons of our synthetic indices with the observational ones from measurements on the INDO-U.S. stellar library, the SDSS-DR7 and SDSS-DR8 spectroscopic survey are presented, respectively, for dwarfs and giants in specific. For dwarfs, our synthetic indices could well reproduce the behaviors of the observational indices versus stellar parameters, which verifies the validity of our index definitions for dwarfs. For giants, the consistency between our synthetic indices and the observational

  13. A NEW SYNTHETIC LIBRARY OF THE NEAR-INFRARED Ca II TRIPLET INDICES. I. INDEX DEFINITION, CALIBRATION, AND RELATIONS WITH STELLAR ATMOSPHERIC PARAMETERS

    SciTech Connect

    Du, W.; Luo, A. L.; Zhao, Y. H. E-mail: lal@nao.cas.cn

    2012-02-15

    Adopting the SPECTRUM package, which is a stellar spectral synthesis program, we have synthesized a comprehensive set of 2890 near-infrared (NIR) synthetic spectra with a resolution and wavelength sampling similar to the Sloan Digital Sky Survey (SDSS) and the forthcoming Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectra. During the synthesis, we applied the 'New grids of ATLAS9 Model Atmosphere' to develop a grid of local thermodynamic equilibrium model atmospheres for effective temperatures (T{sub eff}) ranging from 3500 to 7500 K, for surface gravities (log g) from 0.5 to 5.0 dex, for metallicities ([Fe/H]) from -4.0 to 0.5 dex, and for solar ([{alpha}/Fe] = 0.0 dex) and non-solar ([{alpha}/Fe] = +0.4 dex) abundances. This synthetic stellar library is composed of 1350 solar scaled abundance (SSA) and 1530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR Ca II triplet indices and an index CaT as the sum of the three. These defined indices were automatically measured on every spectrum of the synthetic stellar library and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of {alpha}-element enhancement on the so-defined Ca II indices, we compared indices measured on the SSA spectra with those on the NSSA ones at the same trine of stellar parameters (T{sub eff}, log g, [Fe/H]); luckily, little influences of {alpha}-element enhancement were found. Furthermore, comparisons of our synthetic indices with the observational ones from measurements on the INDO-U.S. stellar library, the SDSS-DR7 and SDSS-DR8 spectroscopic survey are presented, respectively, for dwarfs and giants in specific. For dwarfs, our synthetic indices could well reproduce the behaviors of the observational indices versus stellar parameters, which verifies the validity of our index definitions for dwarfs. For giants, the consistency between our synthetic

  14. Magellanic Cloud Structure from Near-Infrared Surveys. II. Star Count Maps and the Intrinsic Elongation of the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    van der Marel, Roeland P.

    2001-10-01

    I construct a near-IR star count map of the LMC and demonstrate, using the viewing angles derived in Paper I, that the LMC is intrinsically elongated. I argue that this is due to the tidal force from the Milky Way. The near-IR data from the Two Micron All Sky Survey (2MASS) and the Deep Near-Infrared Southern Sky Survey (DENIS) are ideally suited for studies of LMC structure because of the large statistics and insensitivity to dust absorption. The survey data are used to create a star count map of red giant branch and asymptotic giant branch stars. The resulting LMC image shows the well-known bar but is otherwise quite smooth. Ellipse fitting is used for quantitative analysis. The radial number density profile is approximately exponential, with a scale length rd~1.3-1.5 kpc. However, there is an excess density at large radii that may be due to the tidal effect of the Milky Way. The position angle and ellipticity profile both show large radial variations but converge to P.A.maj=189.3d+/-1.4d and ɛ=0.199+/-0.008 for r>~5deg. At large radii, the image is influenced by viewing perspective (i.e., one side of the inclined LMC plane being closer to us than the other). This causes a drift of the center of the star count contours toward the near side of the plane. The observed drift is consistent with the position angle Θ=122.5d+/-8.3d of the list of nodes inferred in Paper I. The fact that Θ differs from P.A.maj indicates that the LMC disk is not circular. Deprojection shows that the LMC has an intrinsic ellipticity ɛ''=0.31 in its outer parts, considerably larger than typical for disk galaxies. The outer contours have a more or less common center, which lies ~0.4 kpc from the center of the bar. Neither agrees with the kinematic center of the H I gas disk. The LMC is elongated in the general direction of the Galactic center and is elongated perpendicular to the Magellanic Stream and the velocity vector of the LMC center of mass. This suggests that the elongation of the

  15. Near infrared detectors for SNAP

    SciTech Connect

    Schubnell, M.; Barron, N.; Bebek, C.; Brown, M.G.; Borysow, M.; Cole, D.; Figer, D.; Lorenzon, W.; Mostek, N.; Mufson, S.; Seshadri, S.; Smith, R.; Tarle, G.

    2006-05-23

    Large format (1k x 1k and 2k x 2k) near infrared detectors manufactured by Rockwell Scientific Center and Raytheon Vision Systems are characterized as part of the near infrared R&D effort for SNAP (the Super-Nova/Acceleration Probe). These are hybridized HgCdTe focal plane arrays with a sharp high wavelength cut-off at 1.7 um. This cut-off provides a sufficiently deep reach in redshift while it allows at the same time low dark current operation of the passively cooled detectors at 140 K. Here the baseline SNAP near infrared system is briefly described and the science driven requirements for the near infrared detectors are summarized. A few results obtained during the testing of engineering grade near infrared devices procured for the SNAP project are highlighted. In particular some recent measurements that target correlated noise between adjacent detector pixels due to capacitive coupling and the response uniformity within individual detector pixels are discussed.

  16. SINS/zC-SINF Survey of z ˜ 2 Galaxy Kinematics: Rest-frame Morphology, Structure, and Colors from Near-infrared Hubble Space Telescope Imaging

    NASA Astrophysics Data System (ADS)

    Tacchella, S.; Lang, P.; Carollo, C. M.; Förster Schreiber, N. M.; Renzini, A.; Shapley, A. E.; Wuyts, S.; Cresci, G.; Genzel, R.; Lilly, S. J.; Mancini, C.; Newman, S. F.; Tacconi, L. J.; Zamorani, G.; Davies, R. I.; Kurk, J.; Pozzetti, L.

    2015-04-01

    We present the analysis of Hubble Space Telescope (HST) J- and H-band imaging for 29 galaxies on the star-forming main sequence at z ˜ 2, which have adaptive optics Very Large Telescope SINFONI integral field spectroscopy from our SINS/zC-SINF program. The SINFONI Hα data resolve the ongoing star formation and the ionized gas kinematics on scales of 1-2 kpc; the near-IR images trace the galaxies’ rest-frame optical morphologies and distributions of stellar mass in old stellar populations at a similar resolution. The global light profiles of most galaxies show disk-like properties well described by a single Sérsic profile with n˜ 1, with only ˜ 15% requiring a high n\\gt 3 Sérsic index, all more massive than {{10}10} {{M}⊙ }. In bulge+disk fits, about 40% of galaxies have a measurable bulge component in the light profiles, with ˜ 15% showing a substantial bulge-to-total ratio (B/T) B/T≳ 0.3. This is a lower limit to the frequency of z ˜ 2 massive galaxies with a developed bulge component in stellar mass because it could be hidden by dust and/or outshined by a thick actively star-forming disk component. The galaxies’ rest-optical half-light radii range between 1 and 7 kpc, with a median of 2.1 kpc, and lie slightly above the size-mass relation at these epochs reported in the literature. This is attributed to differences in sample selection and definitions of size and/or mass measurements. The {{(u-g)}rest} color gradient and scatter within individual z ˜ 2 massive galaxies with ≳ {{10}11} {{M}⊙ } are as high as in z = 0 low-mass, late-type galaxies and are consistent with the high star formation rates of massive z ˜ 2 galaxies being sustained at large galactocentric distances. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute.

  17. Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy

    SciTech Connect

    Guo, Yijun; Rowland, Clare E; Schaller, Richard D; Vela, Javier

    2014-08-26

    Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent II–VI, III–V and IV–VI semiconductor quantum dots. Here, we use relatively unexplored IV/II–VI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch compared with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial II–VI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/II–VI nanocrystals are reproducibly 1–3 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/II–VI nanocrystals. We expect this synthetic IV/II–VI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.

  18. THE LBT BOOeTES FIELD SURVEY. I. THE REST-FRAME ULTRAVIOLET AND NEAR-INFRARED LUMINOSITY FUNCTIONS AND CLUSTERING OF BRIGHT LYMAN BREAK GALAXIES AT Z {approx} 3

    SciTech Connect

    Bian Fuyan; Fan Xiaohui; Jiang Linhua; McGreer, Ian; Dave, Romeel; Dey, Arjun; Green, Richard F.; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo

    2013-09-01

    We present a deep LBT/LBC U{sub spec}-band imaging survey (9 deg{sup 2}) covering the NOAO Booetes field. A total of 14,485 Lyman break galaxies (LBGs) at z {approx} 3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by {>=}3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of z {approx} 3 quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z {approx} 3 LBGs based on the R-band and [4.5 {mu}m]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z {approx} 7 and z {approx} 3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR), which follows the trend predicted by the baryonic accretion rate onto the halo, suggesting that the star formation in LBGs is fueled by baryonic accretion through the cosmic web. By comparing the SFRs with the total baryonic accretion rates, we find that cosmic star formation efficiency is about 5%-20% and it does not evolve significantly with redshift, halo mass, or galaxy luminosity.

  19. New series of ruthenium(II) and osmium(II) complexes showing solid-state phosphorescence in far-visible and near-infrared.

    PubMed

    Chen, Jing-Lin; Chi, Yun; Chen, Kellen; Cheng, Yi-Ming; Chung, Min-Wen; Yu, Ya-Chien; Lee, Gene-Hsiang; Chou, Pi-Tai; Shu, Ching-Fong

    2010-02-01

    A new Ru(II) complex, [Ru(fpbpymH)(2)]Cl(2) (1), in which fpbpymH = [5-(trifluoromethyl)pyrazol-3-yl](2,2'-bipyrid-6-yl)methane, was prepared by the treatment of [Ru(DMSO)(4)Cl(2)] with 2 equiv of the terdentate chelate fpbpymH in refluxing ethanol. A single-crystal X-ray diffraction study of 1 revealed a distorted octahedral Ru(II) framework, showing strong N-H...Cl hydrogen bonding between the fpbpymH ligand and Cl anions. In the presence of Na(2)CO(3), the methylene linkers of chelates in 1 underwent stepwise oxygenation, forming the charge-neutral complexes [Ru(fpbpym)(fpbpyk)] (2) and [Ru(fpbpyk)(2)] (3) [fpbpykH = [5-(trifluoromethyl)pyrazol-3-yl](2,2'-bipyrid-6-yl) ketone] in sequence. The respective charge-neutral Os(II) complex [Os(fpbpyk)(2)] (4) was also isolated by the treatment of OsCl(3).3H(2)O with 2 equiv of the terdentate chelate fpbpymH. Electrochemical analysis indicated that the introduction of the electron-withdrawing ketone group in 2-4 increased the metal-based oxidation potential in sequence. For the photophysical properties, complexes 1-4 are essentially nonluminescent in solution (e.g., CH(2)Cl(2) or MeOH) at room temperature, but all exhibit 600-1100 nm phosphorescence with moderate intensity for the powdery, solid sample at room temperature. The trend in terms of the emission peak wavelength of 1 (666 nm) < 3 (795 nm) < 2 (810 nm) < 4 (994 nm) among titled complexes is in agreement with the corresponding onset of absorption spectra as well as the time-dependent density functional theory calculation of 1 < 3 < 2 < 4. PMID:20030393

  20. STAR CLUSTER COMPLEXES AND THE HOST GALAXY IN THREE H II GALAXIES: Mrk 36, UM 408, AND UM 461

    SciTech Connect

    Lagos, P.; Telles, E.; Nigoche-Netro, A.

    2011-11-15

    We present a stellar population study of three H II galaxies (Mrk 36, UM 408, and UM 461) based on the analysis of new ground-based high-resolution near-infrared J, H, and K{sub p} broadband and Br{gamma} narrowband images obtained with Gemini/NIRI. We identify and determine the relative ages and masses of the elementary star clusters and/or star cluster complexes of the starburst regions in each of these galaxies by comparing the colors with evolutionary synthesis models that include the contribution of stellar continuum, nebular continuum, and emission lines. We found that the current star cluster formation efficiency in our sample of low-luminosity H II galaxies is {approx}10%. Therefore, most of the recent star formation is not in massive clusters. Our findings seem to indicate that the star formation mode in our sample of galaxies is clumpy, and that these complexes are formed by a few massive star clusters with masses {approx}>10{sup 4} M{sub Sun }. The age distribution of these star cluster complexes shows that the current burst started recently and likely simultaneously over short timescales in their host galaxies, triggered by some internal mechanism. Finally, the fraction of the total cluster mass with respect to the low surface brightness (or host galaxy) mass, considering our complete range in ages, is less than 1%.

  1. NEAR-INFRARED COUNTERPARTS TO CHANDRA X-RAY SOURCES TOWARD THE GALACTIC CENTER. II. DISCOVERY OF WOLF-RAYET STARS AND O SUPERGIANTS

    SciTech Connect

    Mauerhan, J. C.; Stolovy, S. R.; Muno, M. P.; Morris, M. R.; Cotera, A.

    2010-02-10

    We present new identifications of infrared counterparts to the population of hard X-ray sources near the Galactic center detected by the Chandra X-ray Observatory. We have spectroscopically confirmed 16 new massive stellar counterparts to the X-ray population, including nitrogen-type (WN) and carbon-type (WC) Wolf-Rayet stars, and O supergiants. These discoveries increase the total sample of massive stellar X-ray sources in the Galactic center region to 30 (possibly 31). For the majority of these sources, the X-ray photometry is consistent with thermal emission from plasma having temperatures in the range of kT = 1-8 keV or non-thermal emission having power-law indices in the range of -1 {approx}< GAMMA {approx}< 3, and X-ray luminosities in the range of L{sub X} {approx} 10{sup 32}-10{sup 34} erg s{sup -1} (0.5-8.0 keV). Several sources have exhibited X-ray variability of several factors between observations. These X-ray properties are not a ubiquitous feature of single massive stars but are typical of massive binaries, in which the high-energy emission is generated by the collision of supersonic winds, or by accretion onto a compact companion. However, without direct evidence for companions, the possibility of intrinsic hard X-ray generation from single stars cannot be completely ruled out. The spectral energy distributions of these sources exhibit significant infrared excess, attributable to free-free emission from ionized stellar winds, supplemented by hot dust emission in the case of the WC stars. With the exception of one object located near the outer regions of the Quintuplet cluster, most of the new stars appear isolated or in loose associations. Seven hydrogen-rich WN and O stars are concentrated near the Sagittarius B H II region, while other similar stars and more highly evolved hydrogen-poor WN and WC stars lie scattered within {approx}50 pc, in projection, of Sagitarrius A West. We discuss various mechanisms capable of generating the observed X

  2. Comparative Variable Temperature Studies of Polyamide II with a Benchtop Fourier Transform and a Miniature Handheld Near-Infrared Spectrometer Using 2D-COS and PCMW-2D Analysis.

    PubMed

    Unger, Miriam; Pfeifer, Frank; Siesler, Heinz W

    2016-07-01

    The main objective of this communication is to compare the performance of a miniaturized handheld near-infrared (NIR) spectrometer with a benchtop Fourier transform near-infrared (FT-NIR) spectrometer. Generally, NIR spectroscopy is an extremely powerful analytical tool to study hydrogen-bonding changes of amide functionalities in solid and liquid materials and therefore variable temperature NIR measurements of polyamide II (PAII) have been selected as a case study. The information content of the measurement data has been further enhanced by exploiting the potential of two-dimensional correlation spectroscopy (2D-COS) and the perturbation correlation moving window two-dimensional (PCMW2D) evaluation technique. The data provide valuable insights not only into the changes of the hydrogen-bonding structure and the recrystallization of the hydrocarbon segments of the investigated PAII but also in their sequential order. Furthermore, it has been demonstrated that the 2D-COS and PCMW2D results derived from the spectra measured with the miniaturized NIR instrument are equivalent to the information extracted from the data obtained with the high-performance FT-NIR instrument.

  3. The LBT Boötes Field Survey. I. The Rest-frame Ultraviolet and Near-infrared Luminosity Functions and Clustering of Bright Lyman Break Galaxies at Z ~ 3

    NASA Astrophysics Data System (ADS)

    Bian, Fuyan; Fan, Xiaohui; Jiang, Linhua; McGreer, Ian; Dey, Arjun; Green, Richard F.; Maiolino, Roberto; Walter, Fabian; Lee, Kyoung-Soo; Davé, Romeel

    2013-09-01

    We present a deep LBT/LBC U spec-band imaging survey (9 deg2) covering the NOAO Boötes field. A total of 14,485 Lyman break galaxies (LBGs) at z ~ 3 are selected, which are used to measure the rest-frame UV luminosity function (LF). The large sample size and survey area reduce the LF uncertainties due to Poisson statistics and cosmic variance by >=3 compared to previous studies. At the bright end, the LF shows excess power compared to the best-fit Schechter function, which can be attributed to the contribution of z ~ 3 quasars. We compute the rest-frame near-infrared LF and stellar mass function (SMF) of z ~ 3 LBGs based on the R-band and [4.5 μm]-band flux relation. We investigate the evolution of the UV LFs and SMFs between z ~ 7 and z ~ 3, which supports a rising star formation history in the LBGs. We study the spatial correlation function of two bright LBG samples and estimate their average host halo mass. We find a tight relation between the host halo mass and the galaxy star formation rate (SFR), which follows the trend predicted by the baryonic accretion rate onto the halo, suggesting that the star formation in LBGs is fueled by baryonic accretion through the cosmic web. By comparing the SFRs with the total baryonic accretion rates, we find that cosmic star formation efficiency is about 5%-20% and it does not evolve significantly with redshift, halo mass, or galaxy luminosity. Based on data acquired using the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University

  4. XID II: STATISTICAL CROSS-ASSOCIATION OF ROSAT BRIGHT SOURCE CATALOG X-RAY SOURCES WITH 2MASS POINT SOURCE CATALOG NEAR-INFRARED SOURCES

    SciTech Connect

    Haakonsen, Christian Bernt; Rutledge, Robert E. E-mail: rutledge@physics.mcgill.ca

    2009-09-01

    The 18,806 ROSAT All Sky Survey Bright Source Catalog (RASS/BSC) X-ray sources are quantitatively cross-associated with near-infrared (NIR) sources from the Two Micron All Sky Survey Point Source Catalog (2MASS/PSC). An association catalog is presented, listing the most likely counterpart for each RASS/BSC source, the probability P {sub id} that the NIR source and X-ray source are uniquely associated, and the probability P {sub no-id} that none of the 2MASS/PSC sources are associated with the X-ray source. The catalog includes 3853 high quality (P {sub id}>0.98) X-ray-NIR matches, 2280 medium quality (0.98 {>=} P {sub id}>0.9) matches, and 4153 low quality (0.9 {>=} P {sub id}>0.5) matches. Of the high quality matches, 1418 are associations that are not listed in the SIMBAD database, and for which no high quality match with a USNO-A2 optical source was presented for the RASS/BSC source in previous work. The present work offers a significant number of new associations with RASS/BSC objects that will require optical/NIR spectroscopy for classification. For example, of the 6133 P {sub id}>0.9 2MASS/PSC counterparts presented in the association catalog, 2411 have no classification listed in the SIMBAD database. These 2MASS/PSC sources will likely include scientifically useful examples of known source classes of X-ray emitters (white dwarfs, coronally active stars, active galactic nuclei), but may also contain previously unknown source classes. It is determined that all coronally active stars in the RASS/BSC should have a counterpart in the 2MASS/PSC, and that the unique association of these RASS/BSC sources with their NIR counterparts thus is confusion limited.

  5. Near infrared laser ocular bioeffects

    SciTech Connect

    Lund, D.J.; Beatrice, E.S.

    1989-05-01

    Thresholds for laser chorioretinal injury in the red end of the visible spectrum and the near-infrared (IR-A) spectral regions are presented. An unpredicted wavelength dependence of the injury threshold for single Q-switched pulses is demonstrated. Four lasers were used to determine thresholds at 40 wavelengths between 532 nm and 1064 nm: a ruby laser, a neodymium:YAG-pumped dye laser, an erbium:YLF laser and an alexandrite laser. Despite many careful and repeated efforts to determine a cause for the variation due to possible variations in the lasers or other aspects of the experimental technique and due to biological absorption properties of the eye, there is no complete or obvious explanation for the significant variations of threshold with small changes in wavelength. The implications of these findings for laser safety standards are presented.

  6. Understanding the near infrared spectrum of quasars

    NASA Astrophysics Data System (ADS)

    Hernán-Caballero, Antonio; Hatziminaoglou, Evanthia; Alonso-Herrero, Almudena; Mateos, Silvia

    2016-08-01

    The rest-frame near infrared (NIR) is a key spectral range for understanding the physics of AGN, but progress has been hindered by the difficulty in defining the NIR spectrum of the accretion disk and removing contamination from stellar emission in the host galaxy. In this talk I will present the analysis of a sample of 85 luminous (L3µm>10^45.5 erg/s) quasars with rest-frame NIR spectroscopy from AKARI and Spitzer/IRS. Their high luminosity allows a direct determination of the NIR shape of the quasar spectrum clean from host galaxy emission. We find that the entire UV-to-MIR SED can be accurately reproduced with a semi-empirical disk+dust model that uses a single template for the accretion disk and two blackbody components (hot and warm) for the dust. The observed diversity in individual SEDs can be accounted for by varying levels of extinction affecting the disk component and differences in the relative luminosities of the disk and dust components. We present a new quasar template [0.1-10µm] as well as separate templates for the disk and dust components, and conclude that previous templates based on less luminous quasars suffer from contamination by stellar emission in the host galaxy, which accounts for up to ~30% of the flux at 1µm. We also perform the first ever measurement of the Paschen_α emission in a large sample of luminous quasars and find that the Paschen_α to optical continuum luminosity ratio is boosted in our sample compared to less luminous quasars.

  7. A NEAR-INFRARED SURVEY OF THE INNER GALACTIC PLANE FOR WOLF-RAYET STARS. II. GOING FAINTER: 71 MORE NEW W-R STARS

    SciTech Connect

    Shara, Michael M.; Faherty, Jacqueline K.; Zurek, David; Moffat, Anthony F. J.; Doyon, Rene; Gerke, Jill; Artigau, Etienne; Drissen, Laurent E-mail: jfaherty@amnh.org E-mail: moffat@astro.umontreal.ca E-mail: gerke@astronomy.ohio-state.edu E-mail: ldrissen@phy.ulaval.ca

    2012-06-15

    We are continuing a J, K and narrowband imaging survey of 300 deg{sup 2} of the plane of the Galaxy, searching for new Wolf-Rayet (W-R) stars. Our survey spans 150 Degree-Sign in Galactic longitude and reaches 1 Degree-Sign above and below the Galactic plane. The survey has a useful limiting magnitude of K = 15 over most of the observed Galactic plane, and K = 14 (due to severe crowding) within a few degrees of the Galactic center. Thousands of emission-line candidates have been detected. In spectrographic follow-ups of 146 relatively bright W-R star candidates, we have re-examined 11 previously known WC and WN stars and discovered 71 new W-R stars, 17 of type WN and 54 of type WC. Our latest image analysis pipeline now picks out W-R stars with a 57% success rate. Star subtype assignments have been confirmed with the K-band spectra and distances approximated using the method of spectroscopic parallax. Some of the new W-R stars are among the most distant known in our Galaxy. The distribution of these new W-R stars is beginning to trace the locations of massive stars along the distant spiral arms of the Milky Way.

  8. Noncovalent Ruthenium(II) Complexes-Single-Walled Carbon Nanotube Composites for Bimodal Photothermal and Photodynamic Therapy with Near-Infrared Irradiation.

    PubMed

    Zhang, Pingyu; Huang, Huaiyi; Huang, Juanjuan; Chen, Hongmin; Wang, Jinquan; Qiu, Kangqiang; Zhao, Donglei; Ji, Liangnian; Chao, Hui

    2015-10-21

    To enhance the efficacy and optimize the treatment of cancers, the integration of multimodal treatment strategies leading to synergistic effects is a promising approach. The coassembly of multifunctional agents for systematic therapies has received considerable interest in cancer treatment. Herein, Ru(II) complex-functionalized single-walled carbon nanotubes (Ru@SWCNTs) are developed as nanotemplates for bimodal photothermal and two-photon photodynamic therapy (PTT-TPPDT). SWCNTs have the ability to load a great amount of Ru(II) complexes (Ru1 or Ru2) via noncovalent π-π interactions. The loaded Ru(II) complexes are efficiently released by the photothermal effect of irradiation from an 808 nm diode laser (0.25 W/cm(2)). The released Ru(II) complexes produce singlet oxygen species ((1)O2) upon two-photon laser irradiation (808 nm, 0.25 W/cm(2)) and can be used as a two-photon photodynamic therapy (TPPDT) agent. Based on the combination of photothermal therapy and two-photon photodynamic therapy, Ru@SWCNTs have greater anticancer efficacies than either PDT using Ru(II) complexes or PTT using SWCNTs in two-dimensional (2D) cancer cell and three-dimensional (3D) multicellular tumor spheroid (MCTS) models. Furthermore, in vivo tumor ablation is achieved with excellent treatment efficacy under a diode laser (808 nm) irradiation at the power density of 0.25 W/cm(2) for 5 min. This study examines an efficacious bimodal PTT and TPPDT nanoplat form for the development of cancer therapeutics.

  9. Near-infrared spectroscopy in NGC 7538

    NASA Astrophysics Data System (ADS)

    Puga, E.; Marín-Franch, A.; Najarro, F.; Lenorzer, A.; Herrero, A.; Acosta Pulido, J. A.; Chavarría, L. A.; Bik, A.; Figer, D.; Ramírez Alegría, S.

    2010-07-01

    Aims: The characterisation of the stellar population in young high-mass star-forming regions allows fundamental cluster properties like distance and age to be constrained. These are essential when using high-mass clusters as probes for conducting Galactic studies. Methods: NGC 7538 is a star-forming region with an embedded stellar population unearthed only in the near-infrared (NIR). We present the first near-infrared spectro-photometric study of the candidate high-mass stellar content in NGC 7538. We obtained H and K spectra of 21 sources with both the multi-object and long-slit modes of LIRIS at the WHT, and complement these data with subarcsecond JHKs photometry of the region using the imaging mode of the same instrument. Results: We find a wide variety of objects within the studied stellar population of NGC 7538. Our results discriminate between a stellar population associated to the H ii region, but not contained within its extent, and several pockets of more recent star formation. We report the detection of CO bandhead emission toward several sources, as well as other features indicative of a young stellar nature. We infer a spectro-photometric distance of 2.7 ± 0.5 kpc, an age spread in the range 0.5-2.2 Myr and a total mass 1.7 × 103 Msun for the older population. Based on observations made with the WHT operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  10. Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications.

    PubMed

    Hsu, Chih-Yu; Zhang, Jian; Sato, Takashi; Moriyama, Satoshi; Higuchi, Masayoshi

    2015-08-26

    Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation. PMID:26225623

  11. Black-to-Transmissive Electrochromism with Visible-to-Near-Infrared Switching of a Co(II)-Based Metallo-Supramolecular Polymer for Smart Window and Digital Signage Applications.

    PubMed

    Hsu, Chih-Yu; Zhang, Jian; Sato, Takashi; Moriyama, Satoshi; Higuchi, Masayoshi

    2015-08-26

    Black-to-transmissive electrochromism has been obtained with a Co(II)-based metallo-supramolecular polymer (polyCo). Thin films of polyCo, based on bisterpyridine ligand assembled with Co(II) metal ion, were constructed by spray casting the polymer onto ITO glass. With such simple fabricating means to form good-quality films, polyCo films show stable switching at the central metal ion of the Co(II)/Co(I) redox reaction when immersed in aqueous solution. With an increase in the pH of the aqueous electrolyte solution from neutral, the film exhibits a color response due to the interaction between the d-orbital electron and hydroxide ions affecting the d-d* transition. As a result, a nearly transparent-to-black electrochromic performance can be achieved with a transmittance difference at 550 nm of 74.3% (81.9-7.6%) in pH 13 solution. The light absorption of the film can be tuned over light regions from visible to near-infrared with a large attenuation.

  12. The VVDS-VLA deep field. II. Optical and near infrared identifications of VLA S1.4 GHz > 80 μ Jy sources in the VIMOS VLT deep survey VVDS-02h field

    NASA Astrophysics Data System (ADS)

    Ciliegi, P.; Zamorani, G.; Bondi, M.; Pozzetti, L.; Bolzonella, M.; Gregorini, L.; Garilli, B.; Iovino, A.; McCracken, H. J.; Mellier, Y.; Radovich, M.; de Ruiter, H. R.; Parma, P.; Bottini, D.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Picat, J. P.; Scaramella, R.; Scodeggio, M.; Tresse, L.; Vettolani, G.; Zanichelli, A.; Adami, C.; Arnaboldi, M.; Arnouts, S.; Bardelli, S.; Cappi, A.; Charlot, S.; Contini, T.; Foucaud, S.; Franzetti, P.; Guzzo, L.; Ilbert, O.; Marano, B.; Marinoni, C.; Mathez, G.; Mazure, A.; Meneux, B.; Merighi, R.; Merluzzi, P.; Paltani, S.; Pollo, A.; Zucca, E.; Bongiorno, A.; Busarello, G.; Gavignaud, I.; Pellò, R.; Ripepi, V.; Rizzo, D.

    2005-10-01

    In this paper we present the optical and near-infrared identifications of the 1054 radio sources detected in the 20 cm deep radio survey down to a 5σ flux limit of ~80 μJy obtained with the VLA in the VIMOS VLT Deep Survey VVDS-02h deep field. Using U,B,V,R,I and K data, with limiting magnitudes of UAB˜25.4, BAB˜26.5, VAB˜26.2, RAB˜25.9 IAB˜25.0, JAB˜24.2, KAB˜23.9 (50% completeness) we identified 718 radio sources (~74% of the whole sample). The photometric redshift analysis shows that, in each magnitude bin, the radio sample has a higher median photometric redshift than the whole optical sample, while the median (V-I)AB color of the radio sources is redder than the median color of the whole optical sample. These results suggest that radio detection is preferentially selecting galaxies with higher intrinsic optical luminosity. From the analysis of the optical properties of the radio sources as function of the radio flux, we found that while about 35% of the radio sources are optically unidentified in the higher radio flux bin (S> 1.0 mJy), the percentage of unidentified sources decreases to about 25% in the faintest bins (S< 0.5 mJy). The median IAB magnitude for the total sample of radio sources, i.e. including also the unidentified ones, is brighter in the faintest radio bins than in the bin with higher radio flux. This suggests that most of the faintest radio sources are likely to be associated to relatively lower radio luminosity objects at relatively modest redshift, rather than radio-powerful, AGN type objects at high redshift. Using a classification in early-type and late-type galaxies based on the (B-I)AB color and the photometric redshift, we found that the majority of the radio sources below ~0.15 mJy are indeed late-type star forming galaxies. Finally, the radio sources without optical counterpart in our deep imaging have a median radio flux of 0.15 mJy, equal to that of identified sources. Given the very faint optical limits, these

  13. Bottled liquid explosive scanner by near infrared

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo

    2016-05-01

    A bottled liquid explosive scanner has been developed using near infrared technology for glass or PET bottles and ultrasound technology for metal cans. It has database of near infrared absorbance spectra and sound velocities of various liquids. Scanned liquids can be identified by using this database. This device has been certified by ECAC and installed at Japanese international airport.

  14. Near-infrared-emitting phthalocyanines. A combined experimental and density functional theory study of the structural, optical, and photophysical properties of Pd(II) and Pt(II) α-butoxyphthalocyanines.

    PubMed

    Soldatova, Alexandra V; Kim, Junhwan; Rizzoli, Corrado; Kenney, Malcolm E; Rodgers, Michael A J; Rosa, Angela; Ricciardi, Giampaolo

    2011-02-01

    The structural, optical, and photophysical properties of 1,4,8,11,15,18,22,25-octabutoxyphthalocyaninato-palladium(II), PdPc(OBu)(8), and the newly synthesized platinum analogue PtPc(OBu)(8) are investigated combining X-ray crystallography, static and transient absorption spectroscopy, and relativistic zeroth-order regular approximation (ZORA) Density Functional Theory (DFT)/Time Dependent DFT (TDDFT) calculations where spin-orbit coupling (SOC) effects are explicitly considered. The results are compared to those previously reported for NiPc(OBu)(8) (J. Phys. Chem. A 2005, 109, 2078) in an effort to highlight the effect of the central metal on the structural and photophysical properties of the group 10 transition metal octabutoxyphthalocyanines. Different from the nickel analogue, PdPc(OBu)(8) and PtPc(OBu)(8) show a modest and irregular saddling distortion of the macrocycle, but share with the first member of the group similar UV-vis spectra, with the deep red and intense Q-band absorption experiencing a blue shift down the group, as observed in virtually all tetrapyrrolic complexes of this triad. The blue shift of the Q-band along the MPc(OBu)(8) (M = Ni, Pd, Pt) series is interpreted on the basis of the metal-induced electronic structure changes. Besides the intense deep red absorption, the title complexes exhibit a distinct near-infrared (NIR) absorption due to a transition to the double-group 1E (π,π*) state, which is dominated by the lowest single-group (3)E (π,π*) state. Unlike NiPc(OBu)(8), which is nonluminescent, PdPc(OBu)(8) and PtPc(OBu)(8) show both deep red fluorescence emission and NIR phosphorescence emission. Transient absorption experiments and relativistic spin-orbit TDDFT calculations consistently indicate that fluorescence and phosphorescence emissions occur from the S(1)(π,π*) and T(1)(π,π*) states, respectively, the latter being directly populated from the former, and the triplet state decays directly to the S(0) surface (the triplet

  15. 21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Near Infrared (NIR) Brain Hematoma Detector. 882... Infrared (NIR) Brain Hematoma Detector. (a) Identification. A Near Infrared (NIR) Brain Hematoma Detector... evaluate suspected brain hematomas. (b) Classification. Class II (special controls). The special...

  16. 21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Near Infrared (NIR) Brain Hematoma Detector. 882... Infrared (NIR) Brain Hematoma Detector. (a) Identification. A Near Infrared (NIR) Brain Hematoma Detector... evaluate suspected brain hematomas. (b) Classification. Class II (special controls). The special...

  17. 21 CFR 882.1935 - Near Infrared (NIR) Brain Hematoma Detector.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Near Infrared (NIR) Brain Hematoma Detector. 882... Infrared (NIR) Brain Hematoma Detector. (a) Identification. A Near Infrared (NIR) Brain Hematoma Detector... evaluate suspected brain hematomas. (b) Classification. Class II (special controls). The special...

  18. Near-Infrared Spectroscopy of Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Boulanger, F.; Onaka, T.; Pilleri, P.; Joblin, C.

    2011-03-01

    Near infrared observations of reflection nebulae have set the historical ground for the discovery of interstellar PAHs, but since, space observations have focused on their mid-IR features, and data shortward of 5 μm have remained scarce. The Spitzer/IRAC images in the 3.6 and 4.5 μm channels do show that the near-IR emission from small dust particles is ubiquitous across the Galaxy, but provide no spectroscopic information. To investigate the nature of this near-IR dust emission, we have obtained AKARI spectroscopic observations, over the 2.5-5 μm spectral range, for a set of archetype PDRs mapped with the Spitzer spectrometer at mid-IR wavelengths. These AKARI data supplement earlier observations with the SWS ISO spectrometer, in providing the gain in sensitivity needed to observe low excitation sources, and the spatial information required to spatially correlate near-IR spectroscopic signatures with physical conditions and observed changes in mid-IR spectra. This paper presents the first results of the data analysis, in relation to two open questions on interstellar PAHs. (1) Is there an evolutionary link from aliphatic carbon dust to PAHs? (2) What is the origin of the near-IR dust continuum? The AKARI spectra display features longward of the main 3.29 μm PAH feature, and continuum emission. The intensity ratio between the features ascribed to aliphatic CH bonds and the 3.29 μm aromatic band, varies spatially in a way that may be interpreted as evidence for aromatization of the smallest dust particles by photo-processing. The continuum displays a striking step-increase across the 3.29 μm feature. We also present a spectrum of a photodissociation region with a feature at 4.65 μm, which has been speculated to be related to the CD stretch in aliphatic hydrocarbon side-groups on PAHs.

  19. FR II radio galaxies at low frequencies

    NASA Astrophysics Data System (ADS)

    Harwood, Jeremy

    2016-08-01

    Due to their steep spectra, low-frequency observations of FR II radio galaxies potentially provide key insights in to the morphology, energetics and underlying physics of these powerful radio sources. However, limitations imposed by the previous generation of radio interferometers at metre wavelengths have meant that this region of parameter space remains largely unexplored.In this talk, we present our latest results using LOFAR and the JVLA at frequencies between 50 and 460 MHz which, along with complementary archival radio and X-ray data, now allows us to undertake well resolved, detailed studies of nearby FR II radio galaxies at low frequencies. We discuss how our improved knowledge of the low-energy electron distribution, magnetic field strength and total energy content of the lobes impacts upon our understanding of the dynamics and energetics of nearby FR II radio galaxies and, for the first time, present the spectral structure of these sources on small spatial scales at low frequencies. We conclude by discussing how these findings change our current understanding of the underlying physics of FR II radio galaxies and, ultimately, their impact on the environment and galaxy evolution as a whole.

  20. Near infrared lasers in flow cytometry.

    PubMed

    Telford, William G

    2015-07-01

    Technology development in flow cytometry has closely tracked laser technology, the light source that flow cytometers almost exclusively use to excite fluorescent probes. The original flow cytometers from the 1970s and 1980s used large water-cooled lasers to produce only one or two laser lines at a time. Modern cytometers can take advantage of the revolution in solid state laser technology to use almost any laser wavelength ranging from the ultraviolet to the near infrared. Commercial cytometers can now be equipped with many small solid state lasers, providing almost any wavelength needed for cellular analysis. Flow cytometers are now equipped to analyze 20 or more fluorescent probes simultaneously, requiring multiple laser wavelengths. Instrument developers are now trying to increase this number by designing fluorescent probes that can be excited by laser wavelength at the "edges" of the visible light range, in the near ultraviolet and near-infrared region. A variety of fluorescent probes have been developed that excite with violet and long wavelength ultraviolet light; however, the near-infrared range (660-800 nm) has yet seen only exploitation in flow cytometry. Fortunately, near-infrared laser diodes and other solid state laser technologies appropriate for flow cytometry have been in existence for some time, and can be readily incorporated into flow cytometers to accelerate fluorescent probe development. The near infrared region represents one of the last "frontiers" to maximize the number of fluorescent probes that can be analyzed by flow cytometry. In addition, near infrared fluorescent probes used in biomedical tracking and imaging could also be employed for flow cytometry with the correct laser wavelengths. This review describes the available technology, including lasers, fluorescent probes and detector technology optimal for near infrared signal detection.

  1. A near infrared spectroscopic study of the interstellar gas in the starburst core of M82

    NASA Technical Reports Server (NTRS)

    Lester, Dan F.; Carr, John; Joy, Marshall; Gaffney, Niall

    1990-01-01

    Researchers used the McDonald Observatory Infrared Grating Spectrometer, to complete a program of spatially resolved spectroscopy of M82. The inner 300 pc of the starburst was observed with 4 inch (50 pc) resolution. Complete J, H and K band spectra with resolution 0.0035 micron (lambda/delta lambda=620 at K) were measured at the near-infrared nucleus of the galaxy. Measurements of selected spectral features including lines of FeII, HII and H2 were observed along the starburst ridge-line, so the relative distribution of the diagnostic features could be understood. This information was used to better define the extinction towards the starburst region, the excitation conditions in the gas, and to characterize the stellar populations there.

  2. Glory of clouds in the near infrared.

    PubMed

    Spinhirne, J D; Nakajima, T

    1994-07-20

    Spectrally resolved visible and infrared images of marine stratus clouds were acquired from the NASA ER-2 high-altitude aircraft during the 1987 First International Cloud Climatology Program Regional Experiment. The images were obtained by cross-track scanning radiometers. Data images at nearinfrared wavelengths show frequent and readily apparent brightness features that are due to glory single scattering. The observations and subsequent analysis by radiative transfer calculations show that the glory is a significant feature of near-infrared solar reflectance from water clouds. Glory observations and calculations based on in-cloud microphysics measurements agree well. The most dramatic difference from the visible glory is that the scattering angles are significantly larger in the near infrared. The glory is also apparently more distinct in the near infrared than in the visible, as scattering size parameters are in a range that effectively produces a glory feature, and also there is less obscuration bymultipe-scattering reflectance because of absorption of radiation by droplets in the near infrared. For both the visible and the near infrared, the principal factors that wash out the glory are dispersion and, to a lesser degree, the effective radius of the cloud droplet-size distribution. The obscuration by multiple scattering in optically thick clouds is secondary. Rather than being a novelty, glory observations would be an accurate and unambiguous technique to sense the droplet size of water clouds remotely.

  3. Neural network cloud screening algorithm Part II: global synthetic cases using high resolution spectra in O2 and CO2 near infrared absorption bands in nadir and sun glint

    NASA Astrophysics Data System (ADS)

    Taylor, Thomas E.; O'Brien, D. M.

    2010-03-01

    In Part I a set of two layer feed-forward neural networks, trained via back propagation of sensitivities, was applied to a synthetic set of radiances in micro-windows of the near-infrared to make predictions of cloud water (cw), cloud ice (ci), effective scattering heights of cloud water and ice, (pcw and pci, respectively) and the column water vapor (w). A threshold test, using 2 g/m-2 for cloud water and 10 g/m-2 for cloud ice, was applied to the retrieved values to distinguish clear from cloudy scenes. In that work the discussion was limited to the nadir viewing geometry, and was applied only to land surfaces, excluding desert and snow and ice fields. Part II describes the extension to a set of high resolution radiances, as might be measured by a grating spectrometer from space, in both nadir and sun glint viewing geometries. Furthermore, results are given for all land surface types as well as scenes over ocean. Prior to neural network training, a Principal Component Analysis (PCA) is applied to the high resolution spectra, which consist of three bands centered at 0.76μm (O2 A-band), 1.61μm (weak CO2 band) and 2.06μm (strong CO2 band), each with 1016 channels. Analysis shows that the five leading EOFs together capture 99.9% of the variance in each band, reducing the data size by more than two orders of magnitude. Application of the trained neural networks to an independent data set, generated using CloudSat and Calipso cloud and aerosol profiles, as well as carbon dioxide profiles from a chemical transport model, were used to quantify the skill in the retrieval. The results vary significantly with surface type, viewing mode and cloud properties. Accuracies range from 7% to 100% (typically close to 75%), with confidence levels almost always greater than 90%.

  4. H II Regions in Interacting Galaxies

    NASA Astrophysics Data System (ADS)

    Frattare, L. M.; Keel, W. C.; Laurikainen, E.

    1993-12-01

    We present a census of H II regions in 50 pairs of interacting galaxies, carried out on CCD and ISIT narrow-band images from Kitt Peak, Lowell, and La Palma. Objects were identified objectively using peak finding at multiple Gaussian smoothing levels to allow for the fact that the larger H II regions are marginally resolved, and measured using aperture photometry. We consider statistics of the space distribution, radial distribution, and luminosity functions. Preliminary analysis shows that the enhancement in star formation is strongest not only in the nuclear regions, but in preferred annuli as well. Interactions can produce significant asymmetries in the star-formation distribution. Some interacting galaxies show flatter luminosity functions for H II regions than seen in normal galaxies, either through an excess of very luminous star-forming complexes or a change in their clumping properties. We compare the statistics of both the location and luminosity of H II regions in interacting systems to results on isolated spirals. This work was supported by the NSF through REU grant AST-9300413 and EPSCoR grant EHR-9108761.

  5. Note: Near infrared interferometric silicon wafer metrology.

    PubMed

    Choi, M S; Park, H M; Joo, K N

    2016-04-01

    In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer. PMID:27131722

  6. Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy system

    SciTech Connect

    Lomanowski, B. A. Sharples, R. M.; Meigs, A. G.; Conway, N. J.; Zastrow, K.-D.; Heesterman, P.; Kinna, D. [EURATOM Collaboration: JET-EFDA Team

    2014-11-15

    The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium Dα, Dβ, Dγ line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

  7. The nature of Hα-selected galaxies at z > 2. II. Clumpy galaxies and compact star-forming galaxies

    SciTech Connect

    Tadaki, Ken-ichi; Kodama, Tadayuki; Koyama, Yusei; Tanaka, Ichi; Hayashi, Masao; Shimakawa, Rhythm

    2014-01-01

    We present the morphological properties of Hα-selected galaxies at z > 2 in SXDF-UDS-CANDELS field. With high-resolution optical/near-infrared images obtained by the Hubble Space Telescope, we identify giant clumps within the Hα emitters (HAEs). We find that at least 41% of our sample shows clumpy structures in the underlying disks. The color gradient of clumps is commonly seen in the sense that the clumps near the galactic center tend to be redder than those in the outer regions. The mid-infrared detection in galaxies with red clumps and the spatial distribution of Hα emission suggest that dusty star-formation activity is probably occurring in the nuclear red clumps. A gas supply to a bulge component through clump migration is one of the most potent physical processes for producing such dusty star-forming clumps and forming massive bulges in local early-type galaxies. They would become large quiescent galaxies at later times just by consumption or blowout of remaining gas. Also, while most of the HAEs have extended disks, we observe two massive, compact HAEs whose stellar surface densities are significantly higher. They are likely to be the direct progenitors of massive, compact quiescent galaxies at z = 1.5-2.0. Two evolutionary paths to massive quiescent galaxies are devised to account for both the size growth of quiescent galaxies and their increased number density from z ∼ 2 to z = 0.

  8. Confusion-limited galaxy fields. II - Classical analyses

    NASA Technical Reports Server (NTRS)

    Chokshi, Arati; Wright, Edward L.

    1989-01-01

    Chokshi and Wright presented a detailed model for simulating angular distribution of galaxy images in fields that extended to very high redshifts. Standard tools are used to analyze these simulated galaxy fields for the Omega(O) = 0 and the Omega(O) = 1 cases in order to test the discriminatory power of these tools. Classical number-magnitude diagrams and surface brightness-color-color diagrams are employed to study crowded galaxy fields. An attempt is made to separate the effects due to stellar evolution in galaxies from those due to the space time geometry. The results show that this discrimination is maximized at near-infrared wavelengths where the stellar photospheres are still visible but stellar evolution effects are less severe than those observed at optical wavelenghts. Rapid evolution of the stars on the asymptotic giant branch is easily recognized in the simulated data for both cosmologies and serves to discriminate between the two extreme values of Omega(O). Measurements of total magnitudes of individual galaxies are not essential for studying light distribution in galaxies as a function of redshift. Calculations for the extragalactic background radiation are carried out using the simulated data, and compared to integrals over the evolutionary models used.

  9. Detection of latent fingerprints by near-infrared spectral imaging

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Dai, Yong

    2014-05-01

    Spectral imaging technology research is becoming more extensive in the field of examination of material evidence. Near-Infrared spectral imaging technology is an important part of the full spectrum of imaging technology. This paper finished the experiment contents of the Near-Infrared spectrum imaging method and image acquisition system Near-Infrared spectral imaging technology. The experiment of Near-Infrared spectral imaging method obtains the image set of the Near-Infrared spectrum, and formats a pseudo-color images to show the potential traces successfully by processing the set of spectral images; Near-Infrared spectral imaging technology explores the technology method of obtaining the image set of Near-Infrared spectrometer and image acquisition system, and extensive access to the Near-Infrared spectrum information of latent blood, stamp and smear fingerprints on common objects, and study the characteristics of the Near-Infrared spectrum. Near-Infrared spectroscopic imaging experiments explores a wide variety of Near-Infrared reflectance spectra of the object material curve and its Near-Infrared spectrum of imaging modalities, can not only gives a reference for choosing Near-Infrared wavelength to show the object surface potential traces of substances, but also gives important data for the Near-Infrared spectrum of imaging technology development.

  10. A genetically targetable near-infrared photosensitizer.

    PubMed

    He, Jianjun; Wang, Yi; Missinato, Maria A; Onuoha, Ezenwa; Perkins, Lydia A; Watkins, Simon C; St Croix, Claudette M; Tsang, Michael; Bruchez, Marcel P

    2016-03-01

    Upon illumination, photosensitizer molecules produce reactive oxygen species that can be used for functional manipulation of living cells, including protein inactivation, targeted-damage introduction and cellular ablation. Photosensitizers used to date have been either exogenous, resulting in delivery and removal challenges, or genetically encoded proteins that form or bind a native photosensitizing molecule, resulting in a constitutively active photosensitizer inside the cell. We describe a genetically encoded fluorogen-activating protein (FAP) that binds a heavy atom-substituted fluorogenic dye, forming an 'on-demand' activated photosensitizer that produces singlet oxygen and fluorescence when activated with near-infrared light. This targeted and activated photosensitizer (TAPs) approach enables protein inactivation, targeted cell killing and rapid targeted lineage ablation in living larval and adult zebrafish. The near-infrared excitation and emission of this FAP-TAPs provides a new spectral range for photosensitizer proteins that could be useful for imaging, manipulation and cellular ablation deep within living organisms.

  11. [Near infrared light irradiator using halogen lamp].

    PubMed

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer.

  12. [Near infrared light irradiator using halogen lamp].

    PubMed

    Ide, Yasuo

    2012-07-01

    The practical electric light bulb was invented by Thomas Alva Edison in 1879. Halogen lamp is the toughest and brightest electric light bulb. With light filter, it is used as a source of near infrared light. Super Lizer and Alphabeam are made as near infrared light irradiator using halogen lamp. The light emmited by Super Lizer is linear polarized near infrared light. The wave length is from 600 to 1,600 nm and strongest at about 1,000 nm. Concerning Super Lizer, there is evidence of analgesic effects and normalization of the sympathetic nervous system. Super Lizer has four types of probes. SG type is used for stellate ganglion irradiation. B type is used for narrow area irradiation. C and D types are for broad area irradiation. The output of Alphabeam is not polarized. The wave length is from 700 to 1,600 nm and the strongest length is about 1,000nm. Standard attachment is used for spot irradiation. Small attachment is used for stellate ganglion irradiation. Wide attachment is used for broad area irradiation. The effects of Alphabeam are thought to be similar to that of Super Lizer. PMID:22860296

  13. Far Outer Galaxy H II Regions

    NASA Technical Reports Server (NTRS)

    Rudolph, A. L.; deGues, E. J.; Brand, J.; Wouterloot, J. G. A.; Gross, Anthony R. (Technical Monitor)

    1994-01-01

    We have made a multifrequency (6, 3.6, and 2 cm), high-resolution (3"-6"), radio continuum survey of IRAS selected sources from the catalogue of Wouterloot & Brand (1989) to search for and study H II regions in the far outer Galaxy. We identified 31 sources in this catalog with well determined galactocentric distances, and with R approx.. greater than 15 kpc and L(sub FIR) approx.greater than 10(exp 4) solar luminosity, indicating the presence of high-mass star-formation. We have observed 11 of these sources with the Very Large Array (VLA). We observed the sources at 6 and 2 cm using "scaled arrays", making possible a direct and reliable comparison of the data at these two wavelengths for the determination of spectral indices. We detected a total of 12 radio sources, of which 10 have spectral indices consistent with optically-thin free-free emission from H II regions. Combined with previous VLA observations by other investigators, we have data on a total of 15 H II regions at galactocentric distances of 15 to 18.2kpc, among the most remote H II regions found in our Galaxy. The sizes of the H II regions range from approx. less than 0.10 to 2.3 pc. Using the measured fluxes and sizes, we determine the electron densities, emission measures, and excitation parameters of the H II regions, as well as the fluxes of Lyman continuum photons needed to keep the nebulae ionized. The sizes and electron densities are consistent with most of the sources detected in this survey being compact or ultracompact H II regions. Seven of the fifteen H II regions have sizes approx. less than 0.20 pc. Assuming simple pressure-driven expansion of the H II regions, these sizes indicate ages approx. less than 5 x 10(exp 4) yr, or only 1% of the lifetime of an O star, which implies an unlikely overabundance of O stars in the outer Galaxy. Thus, the large number of compact H II regions suggests that the time these regions spend in a compact phase must be much longer than their dynamical

  14. Near-Infrared Spectra of Supernovae

    NASA Astrophysics Data System (ADS)

    Gerardy, C. L.; Fesen, R. A.; Hoflich, P.; Nomoto, K.; Garnavich, P. M.; Jha, S.; Challis, P. M.; Kirshner, R. P.; Wheeler, J. C.; Sakai, S.

    2001-12-01

    We present results from a survey of the near-infrared properties of all types of supernovae. Near-infrared spectra of the subluminous Type Ia SN 1999by taken 5 days before to two weeks after maximum light have been analysed using self-consistent SN Ia explosion models. The data generally agree with 1D delayed-detonation models, indicate a near Chandrasekhar-mass WD progenitor, and show low yield of iron-peak elements confined to the innermost layers of the ejecta. This puts strong constraints on the mixing of large iron blobs into the outer layers due to Rayleigh-Taylor instabilities during the deflagration phase. NIR spectra of Type IIP SNe are relatively line-free during the plateau phase, showing largely hydrogen emission with only a handful of other lines, mostly in the 1-1.2 micron region. After the plateau phase, Type IIP spectra become much richer, showing many overlapping emission features throughout the near-infrared. It appears that CO emission is a common feature of core-collapse supernovae, as several detections of first overtone CO emission near 2.3 microns have been made, including SN 1998S (IIn), SN 1999em, SN 1999gi (IIP) and SN 2000ew (Ic). Finally, we find that Type IIn supernovae often exhibit extraordinary infrared excesses at late times. This is probably thermal emission from hot dust, most likely in the dense circumstellar gas surrounding the progenitor star. The infrared luminosity can reach 1041-42 erg s-1, and can last for several years. A possible scenario is that the dust emission is an ``infrared echo'' powered not by the flash of the SN explosion, but rather by UV/X-ray emission from the strong shock interaction with the dense circumstellar material.

  15. Near-infrared spectroscopy of dark asteroids.

    PubMed

    Barucci, M A; Lazzarin, M; Owen, T; Barbieri, C; Fulchignoni, M

    1994-08-01

    Near-infrared (J, H and K bands) spectra of nine dark asteroids (chosen among a sample of supposed primitive objects between C and D classes) have been obtained at the Mauna Kea Observatory (Hawaii) with the 2.2-m telescope using KSPEC as spectrograph. The aim of this work was to search for evidence of the presence of organic materials in these objects as found in other planetary bodies as 5145 Pholus, and in some cometary nuclei. A careful analysis of the data has revealed flat or slightly redder spectra than the solar one for all observed asteroids. No evidence of distinct absorption features was found. PMID:11539179

  16. Near-infrared spectroscopy of dark asteroids.

    PubMed

    Barucci, M A; Lazzarin, M; Owen, T; Barbieri, C; Fulchignoni, M

    1994-08-01

    Near-infrared (J, H and K bands) spectra of nine dark asteroids (chosen among a sample of supposed primitive objects between C and D classes) have been obtained at the Mauna Kea Observatory (Hawaii) with the 2.2-m telescope using KSPEC as spectrograph. The aim of this work was to search for evidence of the presence of organic materials in these objects as found in other planetary bodies as 5145 Pholus, and in some cometary nuclei. A careful analysis of the data has revealed flat or slightly redder spectra than the solar one for all observed asteroids. No evidence of distinct absorption features was found.

  17. Homo- and Heterobimetallic Ruthenium(II) and Osmium(II) Complexes Based on a Pyrene-Biimidazolate Spacer as Efficient DNA-Binding Probes in the Near-Infrared Domain.

    PubMed

    Mardanya, Sourav; Karmakar, Srikanta; Mondal, Debiprasad; Baitalik, Sujoy

    2016-04-01

    We report in this work a new family of homo- and heterobimetallic complexes of the type [(bpy)2M(Py-Biimz)M'(II)(bpy)2](2+) (M = M' = Ru(II) or Os(II); M = Ru(II) and M' = Os(II)) derived from a pyrenyl-biimidazole-based bridge, 2-imidazolylpyreno[4,5-d]imidazole (Py-BiimzH2). The homobimetallic Ru(II) and Os(II) complexes were found to crystallize in monoclinic form with space group P21/n. All the complexes exhibit strong absorptions throughout the entire UV-vis region and also exhibit luminescence at room temperature. For osmium-containing complexes (2 and 3) both the absorption and emission band stretched up to the NIR region and thus afford more biofriendly conditions for probable applications in infrared imaging and phototherapeutic studies. Detailed luminescence studies indicate that the emission originates from the respective (3)MLCT excited state mainly centered in the [M(bpy)2](2+) moiety of the complexes and is only slightly affected by the pyrene moiety. The bimetallic complexes show two successive one-electron reversible metal-centered oxidations in the positive potential window and several reduction processes in the negative potential window. An efficient intramolecular electronic energy transfer is found to occur from the Ru center to the Os-based component in the heterometallic dyad. The binding studies of the complexes with DNA were thoroughly studied through different spectroscopic techniques such as UV-vis absorption, steady-state and time-resolved emission, circular dichroism, and relative DNA binding study using ethidium bromide. The intercalative mode of binding was suggested to be operative in all cases. Finally, computational studies employing DFT and TD-DFT were also carried out to interpret the experimentally observed absorption and emission bands of the complexes. PMID:27011117

  18. Venus in Violet and Near Infrared Light

    NASA Technical Reports Server (NTRS)

    1990-01-01

    These images of the Venus clouds were taken by Galileo's Solid State Imaging System February 13,1990, at a range of about 1 million miles. The smallest detail visible is about 20 miles. The two right images show Venus in violet light, the top one at a time six hours later than the bottom one. They show the state of the clouds near the top of Venus's cloud deck. A right to left motion of the cloud features is evident and is consistent with westward winds of about 230 mph. The two left images show Venus in near infrared light, at the same times as the two right images. Sunlight penetrates through the clouds more deeply at the near infrared wavelengths, allowing a view near the bottom of the cloud deck. The westward motion of the clouds is slower (about 150 mph) at the lower altitude. The clouds are composed of sulfuric acid droplets and occupy a range of altitudes from 30 to 45 miles. The images have been spatially filtered to bring out small scale details and de-emphasize global shading. The filtering has introduced artifacts (wiggly lines running north/south) that are faintly visible in the infrared image. The Galileo Project is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory; its mission is to study Jupiter and its satellites and magnetosphere after multiple gravity assist flybys at Venus and Earth.

  19. A near-infrared spectroscopy computational model for cerebral hemodynamics.

    PubMed

    Kannan, R; Przekwas, A

    2012-11-01

    Near infrared spectroscopy (NIRS) is a technique used to detect and measure changes in the concentrations of oxygenated hemoglobin, deoxygenated hemoglobin, and water in tissues based on the differential absorption, scattering, and refraction of the near infrared light. In this imaging technique, the optical properties of tissues are reconstructed from the measurements obtained from the sensors located on the boundary. A computational method for the rapid noninvasive detection ∕ quantification of cerebral hemorrhage is described using the above procedure. CFD Research Corporation's finite volume computational biology code was used to numerically mimic the NIRS procedure by (i) noninvasively 'numerically penetrating' the brain tissues and (ii) reconstructing the optical properties the presence of water, oxygenated, and deoxygenated blood. These numerical noninvasive measurements are then used to predict the extent and severity of the brain hemorrhage. The paper also discusses ideas to obtain the location and the severity of a localized injury. Two-dimensional and three-dimensional simulations are performed as a proof of concept for the numerical formulation being feasible for the above mentioned detection/quantification. The results demonstrate that this numerical NIRS formulation can be used as a noninvasive technique for both qualitative and quantitative evaluation of cerebral hemodynamics.

  20. MAGIICAT I. THE Mg II ABSORBER-GALAXY CATALOG

    SciTech Connect

    Nielsen, Nikole M.; Churchill, Christopher W.; Kacprzak, Glenn G.; Murphy, Michael T.

    2013-10-20

    We describe the Mg II Absorber-Galaxy Catalog, MAGIICAT, a compilation of 182 spectroscopically identified intermediate redshift (0.07 ≤ z ≤ 1.1) galaxies with measurements of Mg II λλ2796, 2803 absorption from their circumgalactic medium within projected distances of 200 kpc from background quasars. In this work, we present 'isolated' galaxies, which are defined as having no spectroscopically identified galaxy within a projected distance of 100 kpc and a line of sight velocity separation of 500 km s{sup –1}. We standardized all galaxy properties to the ΛCDM cosmology and galaxy luminosities, absolute magnitudes, and rest-frame colors to the B- and K-band on the AB system. We present galaxy properties and rest-frame Mg II equivalent width, W{sub r} (2796), versus galaxy redshift. The well-known anti-correlation between W{sub r} (2796) and quasar-galaxy impact parameter, D, is significant to the 8σ level. The mean color of MAGIICAT galaxies is consistent with an Sbc galaxy for all redshifts. We also present B- and K-band luminosity functions for different W{sub r} (2796) and redshift subsamples: 'weak absorbing' [W{sub r} (2796) < 0.3 Å], 'strong absorbing' [W{sub r} (2796) ≥ 0.3 Å], low redshift (z < (z)), and high redshift (z ≥ (z)), where (z) = 0.359 is the median galaxy redshift. Rest-frame color B – K correlates with M{sub K} at the 8σ level for the whole sample but is driven by the strong absorbing, high-redshift subsample (6σ). Using M{sub K} as a proxy for stellar mass and examining the luminosity functions, we infer that in lower stellar mass galaxies, Mg II absorption is preferentially detected in blue galaxies and the absorption is more likely to be weak.

  1. The Origin of the Excess Near-Infrared Diffuse Sky Brightness: Population III Stars or Zodiacal Light?

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2006-01-01

    The intensity of the diffuse 1 to 5 micron sky emission from which solar system and Galactic foregrounds have been subtracted is in excess of that expected from energy released by galaxies and stars that formed during the z < 5 redshift interval. The spectral signature of this excess near-infrared background light (NIRBL) component is almost identical to that of reflected sunlight from the interplanetary dust cloud, and could therefore be the result of the incomplete subtraction of this foreground emission component from the diffuse sky maps. Alternatively, this emission component could be extragalactic. Its spectral signature is consistent with that of redshifted continuum and recombination line emission from H-II regions formed by the first generation of very massive stars. In this talk I will present the implications of this excess emission for our understanding of the zodiacal dust cloud, the formation rate of Pop III stars, and the TeV gamma-ray opacity to nearby blazars.

  2. Jupiter in blue, ultraviolet and near infrared

    NASA Technical Reports Server (NTRS)

    2000-01-01

    These three images of Jupiter, taken through the narrow angle camera of NASA's Cassini spacecraft from a distance of 77.6 million kilometers (48.2 million miles) on October 8, reveal more than is apparent to the naked eye through a telescope.

    The image on the left was taken through the blue filter. The one in the middle was taken in the ultraviolet. The one on the right was taken in the near infrared.

    The blue-light filter is within the part of the electromagnetic spectrum detectable by the human eye. The appearance of Jupiter in this image is, consequently, very familiar. The Great Red Spot (below and to the right of center) and the planet's well-known banded cloud lanes are obvious. The brighter bands of clouds are called zones and are probably composed of ammonia ice particles. The darker bands are called belts and are made dark by particles of unknown composition intermixed with the ammonia ice.

    Jupiter's appearance changes dramatically in the ultraviolet and near infrared images. These images are near negatives of each other and illustrate the way in which observations in different wavelength regions can reveal different physical regimes on the planet.

    All gases scatter sunlight efficiently at short wavelengths; this is why the sky appears blue on Earth. The effect is even more pronounced in the ultraviolet. The gases in Jupiter's atmosphere, above the clouds, are no different. They scatter strongly in the ultraviolet, making the deep banded cloud layers invisible in the middle image. Only the very high altitude haze appears dark against the bright background. The contrast is reversed in the near infrared, where methane gas, abundant on Jupiter but not on Earth, is strongly absorbing and therefore appears dark. Again the deep clouds are invisible, but now the high altitude haze appears relatively bright against the dark background. High altitude haze is seen over the poles and the equator.

    The Great Red Spot, prominent in all images, is

  3. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    NASA Technical Reports Server (NTRS)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  4. 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.

  5. Evaluation of a near-infrared photomultiplier

    NASA Technical Reports Server (NTRS)

    Evans, W. E.

    1978-01-01

    A high performance near infrared sensitive photomultiplier tube was procured and evaluated with emphasis on those characteristics affecting its use over the very large amplitude range of signals encountered by an airborne lidar intended for mapping the distribution of stratospheric aerosols. A cathode quantum efficiency of 4.3 percent at 1.06 micrometer wavelength and a background count of less than 10,000 per second were realized. It is recommended that the tube be stored and operated at a temperature near -20 C, or cooler. Performance was found acceptable for the application in both pulse counting and analog modes, but careful design, probably including dynamic gain control, will be required to effectively utilize both modes on the same lidar shot.

  6. The Near Infrared Camera (NIRCam) optics

    NASA Astrophysics Data System (ADS)

    Horner, S.; Rieke, M.; Kelly, D.; NIRCam Team

    2005-12-01

    The Near Infrared Camera (NIRCam) for NASA's James Webb Space Telescope (JWST) is one of the four science instruments installed into the Integrated Science Instrument Module (ISIM). NIRCam has very stringent requirements on its optical quality, both to meet the observatory requirement of diffaction-limited images at 2 microns, and because NIRCam is used as the wavefront sensing system in JWST to determine the overall observatory wavefront error. NIRCam operates over the waveband 0.6 to 5.0 microns, must operate with low wavefront error at 37K, and must meet these requirements after a warm launch. This poster is an overview of the NIRCam instrument's optical hardware and performance. The NIRCam instrument is funded by NASA/GSFC under contract NAS5-02105.

  7. Near-infrared spectroscopy for plaque characterization.

    PubMed

    Waxman, Sergio

    2008-12-01

    A near-infrared (NIR) spectroscopy catheter-based system has been developed for intracoronary detection of lipid-rich plaques, capable of scanning an artery through blood and during cardiac motion. The lipid-rich plaque chemometric algorithm was validated in an ex vivo study using coronary artery specimens from autopsy hearts. A parallel clinical study was performed to demonstrate safety of the system in patients and the similarity of spectra acquired in vivo to data from the ex vivo study. Proof of spectral similarity between data obtained in patients and data from autopsy specimens is required to demonstrate the applicability of the algorithm to patients, in whom tissue for analysis is not available. A preliminary analysis in an unblinded cohort of patients from the clinical study reported promising results. The final results of the clinical study will be submitted for publication. The potential clinical value of this NIR spectroscopy device is discussed.

  8. Near-Infrared Intraoperative Chemiluminescence Imaging.

    PubMed

    Büchel, Gabriel E; Carney, Brandon; Shaffer, Travis M; Tang, Jun; Austin, Christine; Arora, Manish; Zeglis, Brian M; Grimm, Jan; Eppinger, Jörg; Reiner, Thomas

    2016-09-20

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce(4+) in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9 pmol cm(-2) of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the in vivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies.

  9. Near-infrared light photoacoustic ophthalmoscopy

    PubMed Central

    Liu, Tan; Wei, Qing; Song, Wei; Burke, Janice M.; Jiao, Shuliang; Zhang, Hao F.

    2012-01-01

    We achieved photoacoustic ophthalmoscopy (PAOM) imaging of the retina with near-infrared (NIR) light illumination. A PAOM imaging system with dual-wavelength illumination at 1064 nm and 532 nm was built. We compared in vivo imaging results of both albino and pigmented rat eyes at the two wavelengths. The results show that the bulk optical absorption of the retinal pigment epithelium (RPE) is only slightly higher than that of the retinal vessels at 532 nm while it becomes more than an order of magnitude higher than that of the retinal vessels at 1064 nm. These studies suggest that although visible light illumination is suitable for imaging both the retinal vessels and the RPE, NIR light illumination, being more comfortable to the eye, is better suited for RPE melanin related investigations and diagnoses. PMID:22574266

  10. Detection of bottled explosives by near infrared

    NASA Astrophysics Data System (ADS)

    Itozaki, Hideo; Sato-Akaba, Hideo

    2013-10-01

    Bottled liquids are not allowed through the security gate in the airport, because liquid explosives have been used by the terrorists. However, passengers have a lot of trouble if they cannot bring their own bottles. For example, a mother would like to carry her own milk in the airplane for her baby. Therefore the detection technology of liquid explosives should be developed as soon as possible. This paper shows that near infrared spectroscopy can detect bottled explosives quickly. The transmission method cannot deal with milk in the sense of liquid inspection. Here we examined the reflection method to the test of milk. The inspection method with light cannot make test for the metal can. We also use ultrasonic method to check metal can simultaneously in order to expand test targets.

  11. Astronomical near-infrared echelle gratings

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth H.; Joyce, Richard R.; Liang, Ming

    2014-07-01

    High-resolution near-infrared echelle spectrographs require coarse rulings in order to match the free spectral range to the detector size. Standard near-IR detector arrays typically are 2 K x 2 K or 4 K x 4 K. Detectors of this size combined with resolutions in the range 30000 to 100000 require grating groove spacings in the range 5 to 20 lines/mm. Moderately high blaze angles are desirable to reduce instrument size. Echelle gratings with these characteristics have potential wide application in both ambient temperature and cryogenic astronomical echelle spectrographs. We discuss optical designs for spectrographs employing immersed and reflective echelle gratings. The optical designs set constraints on grating characteristics. We report on market choices for obtaining these gratings and review our experiments with custom diamond turned rulings.

  12. Precise Near-Infrared Radial Velocities

    NASA Astrophysics Data System (ADS)

    Plavchan, Peter; Gao, P.; Bottom, M.; Davison, C.; Mills, S.; Ciardi, D. R.; Brinkworth, C.; Tanner, A. M.; Beichman, C. A.; Catanzarite, J.; Crawford, S.; Wallace, J.; Mennesson, B.; Johnson, J. A.; White, R. J.; Anglada-Escudé, G.; von Braun, K.; Walp, B.; Vasisht, G.; Kane, S. R.; Prato, L. A.; NIRRVs

    2014-01-01

    We present precise radial velocity time-series from a 2.3 micron pilot survey to detect exoplanets around red, low mass, and young stars. We use the CSHELL spectrograph with an isotopic methane absorption gas cell for common optical path relative wavelength calibration at the NASA InfraRed Telescope Facility. We present an overview of our Nelder-Mead simplex optimization pipeline for extracting radial velocities. We will also present first light data at 1.6 microns from a near-infrared fiber scrambler used in tandem with our gas cell and CSHELL at IRTF. The fiber scrambler makes use of non-circular core fibers to stabilize the illumination of the slit and echelle grating against changes in seeing, focus, guiding and other sources of systematic radial velocity noise, complementing the wavelength calibration of a gas cell.

  13. Designed blending for near infrared calibration.

    PubMed

    Scheibelhofer, Otto; Grabner, Bianca; Bondi, Robert W; Igne, Benoît; Sacher, Stephan; Khinast, Johannes G

    2015-07-01

    Spectroscopic methods are increasingly used for monitoring pharmaceutical manufacturing unit operations that involve powder handling and processing. With that regard, chemometric models are required to interpret the obtained spectra. There are many ways to prepare artificial powder blend samples used in a chemometric model for predicting the chemical content. Basically, an infinite number of possible concentration levels exist in terms of the individual components. In our study, design of experiments for ternary mixtures was used to establish a suitable number of blend compositions that represents the entire mixture region of interest for a three component blend. Various experimental designs and their effect on the predictive power of a chemometric model for near infrared spectra were investigated. It was determined that a particular choice of experimental design could change the predictive power of a model, even with the same number of calibration experiments. PMID:25980978

  14. SPIRou -A Near-Infrared Spectropolarimeter @ CFHT

    NASA Astrophysics Data System (ADS)

    Malo, Lison; Moutou, Claire; Artigau, Etienne; Delfosse, Xavier; Donati, Jean-François; Doyon, Rene; Fouqué, Pascal; Morin, Julien; Martioli, Eder

    2015-12-01

    SPIRou is a near-infrared spectropolarimeter and a high-precision velocimeter optimized for both the detection and characterization of terrestrial planets orbiting nearby low-mass stars, and the study of the impact of magnetic field on the star-planet formation. The spectrograph is designed to record the whole near-infrared spectrum simultaneously in either circular or linear polarization and to reach a RV precision of 1 m/s at a resolving power of 75,000. It will be use to carry out the "SPIRou Legacy Survey" targeting two science objectives (habitable terrestrial planet detection & magnetic field impact on star-planet formation) and is intended to provide the community with an extensive, homogenous, well characterized and high-quality data. SPIRou is expected to make a major breakthrough in the field of telluric planets in the habitable zone of cool stars. Once implemented at CFHT in 2017, SPIRou is expected to be used extensively by the astronomical community - supporting in particular space missions such as TESS, JWST and PLATO. In this presentation, I will focus on the impact of the SPIRou future observing programs in the field of exoplanets: 1) the radial-velocity survey, its target selection of cool dwarfs, strategy and expectations; 2) the follow-up characterization of transiting candidates; 3) the search for giant planets around very young stars; 4) the importance of spectropolarimetry to filter out the intrinsic jitter of target stars at the sub m/s level; 5) the anticipated role in preparing further exoplanet characterization missions.

  15. Deep near-infrared survey of the Southern Sky (DENIS)

    NASA Technical Reports Server (NTRS)

    Deul, E.

    1992-01-01

    DENIS (Deep Near-Infrared Survey of the Southern Sky) will be the first complete census of astronomical sources in the near-infrared spectral range. The challenges of this novel survey are both scientific and technical. Phenomena radiating in the near-infrared range from brown dwarfs to galaxies in the early stages of cosmological evolution, the scientific exploitation of data relevant over such a wide range requires pooling expertise from several of the leading European astronomical centers. The technical challenges of a project which will provide an order of magnitude more sources than given by the IRAS space mission, and which will involve advanced data-handling and image-processing techniques, likewise require pooling of hardware and software resources, as well as of human expertise. The DENIS project team is composed of some 40 scientists, computer specialists, and engineers located in 5 European Community countries (France, Germany, Italy, The Netherlands, and Spain), with important contributions from specialists in Australia, Brazil, Chile, and Hungary. DENIS will survey the entire southern sky in 3 colors, namely in the I band at a wavelength of 0.8 micron, in the 1.25 micron J band, and in the 2.15 micron K' band. The sensitivity limits will be 18th magnitude in the I band, 16th in the J band, and 14.5th in the K' band. The angular resolution achieved will be 1 arcsecond in the I band, and 3.0 arcseconds in the J and K' bands. The European Southern Observatory 1 m telescope on La Silla will be dedicated to survey use during operations expected to last four years, commencing in late 1993. DENIS aims to provide the astronomical community with complete digitized infrared images of the full southern sky and a catalogue of extracted objects, both of the best quality and in readily accessible form. This will be achieved through dedicated software packages and specialized catalogues, and with assistance from the Leiden and Paris Data Analysis Centers. The data

  16. STELLAR POPULATIONS AND THE STAR FORMATION HISTORIES OF LOW SURFACE BRIGHTNESS GALAXIES. II. H II REGIONS

    SciTech Connect

    Schombert, James; McGaugh, Stacy; Maciel, Tamela E-mail: stacy.mcgaugh@case.edu

    2013-08-01

    The luminosities, colors, and H{alpha} emission for 429 H II regions in 54 low surface brightness (LSB) galaxies are presented. While the number of H II regions per galaxy is lower in LSB galaxies compared to star-forming irregulars and spirals, there is no indication that the size or luminosity function of H II regions differs from other galaxy types. The lower number of H II regions per galaxy is consistent with their lower total star formation rates. The fraction of the total L{sub H{alpha}} contributed by H II regions varies from 10% to 90% in LSB galaxies (the rest of the H{alpha} emission being associated with a diffuse component) with no correlation with galaxy stellar or gas mass. Bright H II regions have bluer colors, similar to the trend in spirals; their number and luminosities are consistent with the hypothesis that they are produced by the same H II luminosity function as spirals. Comparison with stellar population models indicates that the brightest H II regions in LSB galaxies range in cluster mass from a few 10{sup 3} M{sub Sun} (e.g., {rho} Oph) to globular-cluster-sized systems (e.g., 30 Dor) and that their ages are consistent with clusters from 2 to 15 Myr old. The faintest H II regions are comparable to those in the LMC powered by a single O or B star. Thus, star formation in LSB galaxies covers the full range of stellar cluster mass.

  17. A correlation between the stellar and [Fe II] velocity dispersions in active galaxies

    NASA Astrophysics Data System (ADS)

    Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Riffel, Rogério; Pastoriza, Miriani G.; Rodríguez-Ardila, Alberto; Dors, Oli L.; Fuchs, Jaciara; Diniz, Marlon R.; Schönell, Astor J.; Hennig, Moiré G.; Brum, Carine

    2013-03-01

    We use near-infrared (near-IR) spectroscopic data from the inner few hundred parsecs of a sample of 47 active galaxies to investigate possible correlations between the stellar velocity dispersion (σ⋆), obtained from the fit of the K-band CO stellar absorption bands, and the gas velocity dispersion (σ), obtained from the fit of the emission-line profiles of [S III] λ0.953 μm, [Fe II] λ1.257 μm, [Fe II] λ1.644 μm and H2 λ2.122 μm. While no correlations with σ⋆ were found for H2 and [S III], a good correlation was found for the two [Fe II] emission lines, expressed by the linear fit σ _star = 95.4± 16.1 + (0.25± 0.08)× σ _{[Fe {II}]}. Excluding barred objects from the sample, a better correlation is found between σ⋆ and σ _{[Fe {II}]}, with a correlation coefficient of R = 0.80 and fitted by the following relation: σ _star = 57.9± 23.5 + (0.42± 0.10)× σ _{[Fe {II}]}. This correlation can be used to estimate σ⋆ in cases where it cannot be directly measured and the [Fe II] emission lines are present in the spectra, allowing us to obtain the mass of the supermassive black hole (SMBH) from the M•-σ⋆ relation. The scatter from a one-to-one relationship between σ⋆ and its value derived from σ _{[Fe {II}]} using the equation above for our sample is 0.07 dex, which is smaller than that obtained in previous studies which use σ _{[O {III}]} in the optical as a proxy for σ⋆. The use of σ _{[Fe {II}]} in the near-IR instead of σ _{[O {III}]} in the optical is a valuable option for cases in which optical spectra are not available or are obscured, as in the case of many active galactic nuclei. The comparison between the SMBH masses obtained using the M•-σ⋆ relation in which σ⋆ was directly measured with those derived from σ _{[Fe {II}]} reveals only a small average difference of Δ log M• = 0.02 with a scatter of 0.32 dex for the complete sample and Δ log M• = 0.00 with a scatter of 0.28 dex for a subsample excluding

  18. Near-Infrared H-Band Features in Late O and B Stars

    NASA Astrophysics Data System (ADS)

    Hanson, M. M.; Rieke, G. H.; Luhman, K. L.

    1998-10-01

    We examine the spectral characteristics of normal OB stars with high-signal-to-noise ratio (>120) H-band (1.6 μm) spectra at a resolution of 2000. We find that several atomic lines vary smoothly with stellar temperature, as first shown by Blum et al. However, we find a previously unreported, significant variation in the strength of some of these lines with stellar luminosity. B supergiant stars show stronger He i and weaker Br 11 as compared with low-luminosity B dwarf stars of the same spectral class. It is for this reason that luminosity class must also be determined to obtain an accurate spectral type for a given star using H-band spectra. We suggest a method for estimating the spectral type and luminosity of an OB star over the wavelength range from 1.66 to 1.72 μm using hydrogen Br 11 at 1.681 mum, He i at 1.700 mum, and He ii at 1.693 mum. The use of the near-infrared spectral range for classification has obvious advantages over optical classification when applied to heavily reddened stars, such as in star-forming regions or deeply embedded lines of sight within the plane of the Galaxy, such as the Galactic center. Furthermore, the H band is less likely to be contaminated by infrared excess emission, which is frequently seen around massive young stellar objects beyond 2 mum.

  19. Near-Infrared spectroscopy of Nova Sco 2016 (PNV J17381927-3725077)

    NASA Astrophysics Data System (ADS)

    Srivastava, Mudit; Banerjee, D. P. K.; Ashok, N. M.; Joshi, Vishal

    2016-06-01

    Near-infrared observations are reported of Nova Sco 2016 detected in outburst on 10.629 June 2016 (CBET 4285). A classification of the nova as a Fe II or He/N type was not suggested from its optical spectrum (CBET 4285).

  20. Near infrared Raman spectra of Rhizoma dioscoreae

    NASA Astrophysics Data System (ADS)

    Lin, Wenshuo; Chen, Rong; Chen, Guannan; Feng, Sangyuan; Li, Yongzeng; Huang, Zufang; Li, Yongsen

    2008-03-01

    A novel and compact near-infrared (NIR) Raman system is developed using 785-nm diode laser, volume-phase technology holographic system, and NIR intensified charge-coupled device (CCD). Raman spectra and first derivative spectra of Rhizoma Dioscoreae are obtained. Raman spectra of Rhizoma Dioscoreae showed three strong characteristic peaks at 477.4cm -1, 863.9cm -1, and 936.0cm -1. The major ingredients are protein, amino acid, starch, polysaccharides and so on, matched with the known basic biochemical composition of Rhizoma Dioscoreae. In the first derivative spectra of Rhizoma Dioscoreae, distinguishing characteristic peaks appeared at 467.674cm -1, 484.603cm -1, 870.37cm -1, 943.368cm -1. Contrasted with Rhizoma Dioscoreae Raman spectra, in 600cm -1 to 800cm -1, 1000cm -1 to 1400cm -1 regions, changes in Rhizoma Dioscoreae Raman first derivative spectra are represented more clearly than Rhizoma Dioscoreae Raman spectra. So Rhizoma Dioscoreae raman first derivative spectra can be an accurate supplementary analysis method to Rhizoma Dioscoreae Raman spectra.

  1. Near-Infrared Diffuse Optical Tomography

    PubMed Central

    Hielscher, A. H.; Bluestone, A. Y.; Abdoulaev, G. S.; Klose, A. D.; Lasker, J.; Stewart, M.; Netz, U.; Beuthan, J.

    2002-01-01

    Diffuse optical tomography (DOT) is emerging as a viable new biomedical imaging modality. Using near-infrared (NIR) light, this technique probes absorption as well as scattering properties of biological tissues. First commercial instruments are now available that allow users to obtain cross-sectional and volumetric views of various body parts. Currently, the main applications are brain, breast, limb, joint, and fluorescence/bioluminescence imaging. Although the spatial resolution is limited when compared with other imaging modalities, such as magnetic resonance imaging (MRI) or X-ray computerized tomography (CT), DOT provides access to a variety of physiological parameters that otherwise are not accessible, including sub-second imaging of hemodynamics and other fast-changing processes. Furthermore, DOT can be realized in compact, portable instrumentation that allows for bedside monitoring at relatively low cost. In this paper, we present an overview of current state-of-the -art technology, including hardware and image-reconstruction algorithms, and focus on applications in brain and joint imaging. In addition, we present recent results of work on optical tomographic imaging in small animals. PMID:14646043

  2. A near-infrared confocal scanner

    NASA Astrophysics Data System (ADS)

    Lee, Seungwoo; Yoo, Hongki

    2014-06-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface.

  3. Near-infrared brightening of BL Lacertae

    NASA Astrophysics Data System (ADS)

    Carnerero, M. I.; Gonzalez, A. I.; Pulido, J. A. Acosta; Raiteri, C. M.; Villata, M.

    2012-07-01

    Near-infrared observations at the Teide Observatory, in the framework of the GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) confirm a rapid brightening of BL Lacertae, as reported by ATel#4271. Here we report on four observations obtained at the Carlos Sanchez Telescope in a week period, according to which the source has increased its brightness by 0.7 mag. On 2012 July 20.14 the source was observed at J=11.25 +/-0.01 (H=10.27+/-0.01 and Ks=9.46+/-0.01), on July 21.15 at J=11.00+/-0.02 (H=10.02+/-0.02, Ks=9.21+/-0,02), on July 24.98 at J=10.72+/-0.01 (H=9.76+/-0.01, Ks=8.94+/-0.01), and on July 26.12 at J=10.57+/-0.01 (H=9.58+/-0.01, Ks=8.77+/-0.01).

  4. Achromatic lens systems for near infrared instruments.

    NASA Astrophysics Data System (ADS)

    Oliva, E.; Gennari, S.

    1995-11-01

    The chromatic characteristics of glasses transmitting in the near infrared (λ<=2.5μm) are analyzed. Achromatic systems with superb characteristics can be obtained by coupling the crystals BaF_2_, SrF_2_ and CaF_2_ with the IR Schott glasses irg2, irg3 and irg7, respectively. The best performances are obtained using BaF_2_-irg2 and SrF_2_- irg3 while CaF_2_-irg7 is worse (due to the lower Abbe number of CaF_2_) but significantly better than other pairs normally used in IR astronomical instrumentation. Use of these combinations could much simplify the design of astronomical focal plane instruments. Measurements of the refraction index of the IR glasses at cryogenic temperatures are however necessary. As a practical application we present the preliminary design of a F/11-F/4.3 focal reducer for the Italian 3.5 m Galileo telescope. The system employs 6 spherical lenses and its image quality matches the requirements of a 1024^2^ array with 18.5μm pixels in both the imaging and spectroscopic (with grism) modes.

  5. Near-infrared spectroscopy for personal screening

    NASA Astrophysics Data System (ADS)

    Canal, Céline M.; Saleem, Aamer; Green, Roger J.; Hutchins, David A.

    2010-10-01

    This paper will demonstrate that near infrared (NIR) signals at wavelengths in the range 0.9 to 2.5 microns can be used for personal screening applications. At these wavelengths, there is sufficient spectral information to provide chemical identification, while still providing transmission through many types of common clothing materials. Thus, chemical identification in diffuse reflection is possible. Initial measurements on selected clothing materials have indicated that there is sufficient transmission to allow NIR spectra from concealed chemicals to be collected. The effect of the clothing material on the observed spectra has also been quantified. The clothing materials ranged from cotton to man-made fibres. Spectra have been collected at stand-off distances of several metres or more, using a suitable lens system and an NIR spectrometer. The optics required to achieve this will be described, and some spectra from chemicals hidden behind clothing will be presented. The further steps necessary to provide correct identification of chemicals such as ammonium nitrate in granular form will also be given, involving signal analysis methods. A set of spectra will be shown that have been collected and analysed, for a wide range of clothing fabric materials, indicating that the technique could have wide application to personal screening situations.

  6. Near-infrared probes: design and applications

    NASA Astrophysics Data System (ADS)

    Patonay, G.; Strekowski, L.; Raszkiewicz, A.; Kim, J. S.

    2006-02-01

    Near-Infrared (NIR) absorbing chromophores have been valuable in analytical and bioanalytical chemistry. NIR probes and labels have been used for several applications, including solvent polarity, hydrophobicity, DNA sequencing, immunoassays, CE separations, etc. The NIR region (700-1100 nm) is more advantageous for the bioanalytical chemist due to the inherently lower background interference and the high molar absorptivities. NIR dyes can be used as simple probes to investigate biomolecule properties or just simply to detect the presence of biomolecules. Another typical application is the use of NIR fluorophores as labels. In these applications covalent labeling is the preferred method but it requires NIR dyes with appropriate reactive moieties. Due to the hydrophobic nature of NIR chromophores non-covalent labeling may be a viable alternative. For this purpose novel bis(carbocynines) have been developed in our laboratories. These dyes form intramolecular H-aggregates in polar solvents, even at very low concentrations. Spectral properties of this intramolecular dimer greatly depend on the properties of heterocyclic moieties and the length, the location and/or flexibility of the connecting chain. This form of the dye can be described as a clamshell complex with two interacting hydrophobic carbocyanine moieties. This intramolecular H-aggregate has a low extinction coefficient and fluorescence quantum yield. Upon opening the clamshell that can be facilitated by changing microhydrophobicity (i.e., binding to biomolecules) the H-and D- bands are decreased and the monomeric band is increased, with concomitant increase in fluorescence intensity. The main analytical utility of these bis(carbocyanines) is that the free dye (i.e., not complexed to an analyte) has negligible fluorescence in a typical aqueous buffer environment. Examples of different applications of these bis(carbocyanines) are given including forensic applications.

  7. Near-infrared imaging of Markarian 231: Evidence for a double nucleus

    NASA Technical Reports Server (NTRS)

    Armus, L.; Surace, J. A.; Soifer, B. T.; Matthews, K.; Graham, J. R.; Larkin, J. E.

    1994-01-01

    Near-infrared (1.2-2.4 micrometers) images are presented for the central 10 arcsec of the Seyfert 1 galaxy Markarian 231. We find a faint, but intrinsically luminous (M(sub k) approximately -20.7) secondary peak in the near-infrared light distribution approximately 3.5 arcsec (2.7 kpc) south of the primary Seyfert 1 nucleus. Since there is no optical or infrared evidence for ongoing star formation at the location of this secondary peak, and its near-infrared luminosity and color are comparable to slightly reddened spiral bulges or elliptical nuclei, we identify this peak with the stripped nucleus of the companion galaxy involved in the Mrk 231 merger event. Depending upon the exact ratio of the masses of the primary and secondary nucleus in the Mrk 231 system we estimate a merger time scale of less than or equal to 10(exp 9) yr. The morphology of the southern nucleus suggests that it may have recently survived a close passage (r less than 200 pc) with the Seyfert 1 nucleus on a highly elliptical orbit, in which case the merger time scale may be significantly shorter (approximately 10(exp 7) yr. We re-calculate the average merger time scale for the seven ultraluminous infrared galaxies with double nuclei in the Bright Galaxy Sample (the BGS) of Soifer et al. (AJ, 98, 766 (1989)) and derive a value of approximately 10(exp 8) yr. Since seven of ten of the ultraluminous infrared galaxies in the BGS are now known to be double, we estimate the ultraluminous 'phase' may be close to this value. Along with Arp 220 and Mrk 273, Mrk 231 is the third member of the class to possess a high brightness temperature non-thermal radio core and a double nucleus, suggesting the time scale for the generation or fueling of the active nucleus can be much less than the dynamical time scale for the merger of the progenitor nuclei.

  8. Determination of edible oil parameters by near infrared spectrometry.

    PubMed

    Armenta, S; Garrigues, S; de la Guardia, M

    2007-07-23

    A chemometric method has been developed for the determination of acidity and peroxide index in edible oils of different types and origins by using near infrared spectroscopy (NIR) measurements. Different methods for selecting the calibration set, after an hierarchical cluster analysis, were applied. After discrimination of olive oils from maize, seed and sunflower, the prediction capabilities of partial least squares (PLS) multivariate calibration of NIR data were evaluated. Several preprocessing alternatives (first derivative, multiplicative scatter correction, vector normalization, constant offset elimination, mean centering and standard normal variate) were investigated by using the root mean square error of validation (RMSEV) and prediction (RMSEP), as control parameters. Under the best conditions studied, the validation set provides RMSEP values of 0.034 and 0.037% (w/w) for acidity in (I) olive oil group and (II) sunflower, seed and maize oils group. RMSEP values for peroxide in both sample groups, expressed as mequiv.O2 kg(-1), were, respectively 1.87 and 0.79. The limit of detection of the methodology developed was 0.03% for acidity in both groups of edible oils (I and II), and 0.9 and 0.8 mequiv.O2 kg(-1) for peroxide in the olive oil and other edible oils groups, respectively. In fact, the methodology developed is proposed for direct acidity quantification and for the screening of peroxide index in edible oils, requiring less than 30 s per sample without any previous treatment.

  9. [Drug release system controlled by near infrared light].

    PubMed

    Niidome, Takuro

    2013-01-01

    Gold nanorods have absorption bands in the near-infrared region; in this spectral range, light penetrates deeply into tissues. The absorbed light energy is converted into heat by gold nanorods. This is the so-called photothermal effect. Gold nanorods are therefore expected to act not only as thermal converters for photothermal therapy, but also as controllers for drug-release systems responding to irradiation with near-infrared light. To achieve a controlled-release system that could be triggered by light irradiation, the gold nanorods were modified with double-stranded DNA (dsDNA). When the dsDNA-modified gold nanorods were irradiated with near-infrared light, single-stranded DNA (ssDNA) was released from the gold nanorods because of the photothermal effect. The release of ssDNA was also observed in tumors grown on mice after near-infrared light irradiation. We also proposed a different controlled-release system responding to near-infrared light. Gold nanorods were modified with polyethylene glycol (PEG) through Diels-Alder cycloadducts. When the gold nanorods were irradiated with near-infrared light, the PEG chains were released from the gold nanorods because of the retro Diels-Alder reaction induced by the photothermal effect. Such controlled-release systems triggered by near-infrared light irradiation will be expanded for gold nanorod drug delivery system applications.

  10. NIRMOS: a wide-field near-infrared spectrograph for the Giant Magellan Telescope

    NASA Astrophysics Data System (ADS)

    Fabricant, Daniel; Fata, Robert; Brown, Warren R.; McLeod, Brian; Mueller, Mark; Gauron, Thomas; Roll, John; Bergner, Henry; Geary, John; Kradinov, Vladimir; Norton, Tim; Smith, Matt; Zajac, Joseph

    2012-09-01

    NIRMOS (Near-Infrared Multiple Object Spectrograph) is a 0.9 to 2.5 μm imager/spectrograph concept proposed for the Giant Magellan Telescope1 (GMT). Near-infrared observations will play a central role in the ELT era, allowing us to trace the birth and evolution of galaxies through the era of peak star formation. NIRMOS' large field of view, 6.5′ by 6.5′, will be unique among imaging spectrographs developed for ELTs. NIRMOS will operate in Las Campanas' superb natural seeing and is also designed to take advantage of GMT's ground-layer adaptive optics system. We describe NIRMOS' high-performance optical and mechanical design.

  11. Advances in Organic Near-Infrared Materials and Emerging Applications.

    PubMed

    Qi, Ji; Qiao, Wenqiang; Wang, Zhi Yuan

    2016-06-01

    Much progress has been made in the field of research on organic near-infrared materials for potential applications in photonics, communications, energy, and biophotonics. This account mainly describes our research work on organic near-infrared materials; in particular, donor-acceptor small molecules, organometallics, and donor-acceptor polymers with the bandgaps less than 1.2 eV. The molecular designs, structure-property relationships, unique near-infrared absorption, emission and color/wavelength-changing properties, and some emerging applications are discussed.

  12. Near-infrared line identification in type Ia supernovae during the transitional phase

    SciTech Connect

    Friesen, Brian; Baron, E.; Wisniewski, John P.; Miller, Timothy R.; Parrent, Jerod T.; Thomas, R. C.; Marion, G. H.

    2014-09-10

    We present near-infrared synthetic spectra of a delayed-detonation hydrodynamical model and compare them to observed spectra of four normal Type Ia supernovae ranging from day +56.5 to day +85. This is the epoch during which supernovae are believed to be undergoing the transition from the photospheric phase, where spectra are characterized by line scattering above an optically thick photosphere, to the nebular phase, where spectra consist of optically thin emission from forbidden lines. We find that most spectral features in the near-infrared can be accounted for by permitted lines of Fe II and Co II. In addition, we find that [Ni II] fits the emission feature near 1.98 μm, suggesting that a substantial mass of {sup 58}Ni exists near the center of the ejecta in these objects, arising from nuclear burning at high density.

  13. Precise radial velocities in the near infrared

    NASA Astrophysics Data System (ADS)

    Redman, Stephen L.

    Since the first detection of a planet outside our Solar System byWolszczan & Frail (1992), over 500 exoplanets have been found to date2, none of which resemble the Earth. Most of these planets were discovered by measuring the radial velocity (hereafter, RV) of the host star, which wobbles under the gravitational influence of any existing planetary companions. However, this method has yet to achieve the sub-m/s precision necessary to detect an Earth-mass planet in the Habitable Zone (the region around a star that can support liquid water; hereafter, HZ) (Kasting et al. 1993) around a Solar-type star. Even though Kepler (Borucki et al. 2010) has announced several Earth-sized HZ candidates, these targets will be exceptionally difficult to confirm with current astrophysical spectrographs (Borucki et al. 2011). The fastest way to discover and confirm potentiallyhabitable Earth-mass planets is to observe stars with lower masses - in particular, late M dwarfs. While M dwarfs are readily abundant, comprising some 70% of the local stellar population, their low optical luminosity presents a formidable challenge to current optical RV instruments. By observing in the near-infrared (hereafter, NIR), where the flux from M dwarfs peaks, we can potentially reach low RV precisions with significantly less telescope time than would be required by a comparable optical instrument. However, NIR precision RV measurements are a relatively new idea and replete with challenges: IR arrays, unlike CCDs, are sensitive to the thermal background; modal noise is a bigger issue in the NIR than in the optical; and the NIR currently lacks the calibration sources like the very successful thorium-argon (hereafter, ThAr) hollow-cathode lamp and Iodine gas cell of the optical. The PSU Pathfinder (hereafter, Pathfinder) was designed to explore these technical issues with the intention of mitigating these problems for future NIR high-resolution spectrographs, such as the Habitable-Zone Planet Finder (HZPF

  14. Modeling the distribution of Mg II absorbers around galaxies using background galaxies and quasars

    SciTech Connect

    Bordoloi, R.; Lilly, S. J.; Kacprzak, G. G.; Churchill, C. W.

    2014-04-01

    We present joint constraints on the distribution of Mg II absorption around high redshift galaxies obtained by combining two orthogonal probes, the integrated Mg II absorption seen in stacked background galaxy spectra and the distribution of parent galaxies of individual strong Mg II systems as seen in the spectra of background quasars. We present a suite of models that can be used to predict, for different two- and three-dimensional distributions, how the projected Mg II absorption will depend on a galaxy's apparent inclination, the impact parameter b and the azimuthal angle between the projected vector to the line of sight and the projected minor axis. In general, we find that variations in the absorption strength with azimuthal angles provide much stronger constraints on the intrinsic geometry of the Mg II absorption than the dependence on the inclination of the galaxies. In addition to the clear azimuthal dependence in the integrated Mg II absorption that we reported earlier in Bordoloi et al., we show that strong equivalent width Mg II absorbers (W{sub r} (2796) ≥ 0.3 Å) are also asymmetrically distributed in azimuth around their host galaxies: 72% of the absorbers in Kacprzak et al., and 100% of the close-in absorbers within 35 kpc of the center of their host galaxies, are located within 50° of the host galaxy's projected semi minor axis. It is shown that either composite models consisting of a simple bipolar component plus a spherical or disk component, or a single highly softened bipolar distribution, can well represent the azimuthal dependencies observed in both the stacked spectrum and quasar absorption-line data sets within 40 kpc. Simultaneously fitting both data sets, we find that in the composite model the bipolar cone has an opening angle of ∼100° (i.e., confined to within 50° of the disk axis) and contains about two-thirds of the total Mg II absorption in the system. The single softened cone model has an exponential fall off with azimuthal

  15. DERIVING METALLICITIES FROM THE INTEGRATED SPECTRA OF EXTRAGALACTIC GLOBULAR CLUSTERS USING THE NEAR-INFRARED CALCIUM TRIPLET

    SciTech Connect

    Foster, Caroline; Forbes, Duncan A.; Proctor, Robert N.; Spitler, Lee R.; Strader, Jay; Brodie, Jean P.

    2010-04-15

    The Ca II triplet (CaT) feature in the near-infrared has been employed as a metallicity indicator for individual stars as well as integrated light of Galactic globular clusters (GCs) and galaxies with varying degrees of success, and sometimes puzzling results. Using the DEIMOS multi-object spectrograph on Keck we obtain a sample of 144 integrated light spectra of GCs around the brightest group galaxy NGC 1407 to test whether the CaT index can be used as a metallicity indicator for extragalactic GCs. Different sets of single stellar population models make different predictions for the behavior of the CaT as a function of metallicity. In this work, the metallicities of the GCs around NGC 1407 are obtained from CaT index values using an empirical conversion. The measured CaT/metallicity distributions show unexpected features, the most remarkable being that the brightest red and blue GCs have similar CaT values despite their large difference in mean color. Suggested explanations for this behavior in the NGC 1407 GC system are (1) the CaT may be affected by a population of hot blue stars, (2) the CaT may saturate earlier than predicted by the models, and/or (3) color may not trace metallicity linearly. Until these possibilities are understood, the use of the CaT as a metallicity indicator for the integrated spectra of extragalactic GCs will remain problematic.

  16. [Identification of Metoprolol Tartrate Tablets from Different Manufacturers by Different Near Infrared Spectrometers].

    PubMed

    Li, Qi-lu; Wang, Fei; Wang, Jin-feng; Zang, Heng-chang; Zhang, Hui; Jiang, Wei

    2015-10-01

    To rapidly identify Metoprolol Tartrate tablets from different manufacturers, a qualitative analysis model can be established by near infrared spectroscopy. Firstly, AntarisII Fourier-transform near infrared (FT-NIR) spectroscopy and Micro NIR1700 Spectrometer were used to collect spectral data of 66 batches of samples which come from four different manufacturers, then 44 samples of calibration set and 22 samples of validation set were acquired by random sampling. In order to build up a PLS-DA model, the first derivative with Savitzky-Golay 15 points smoothing (1d+SG15) and standard normal vitiate transformation (SNV) was selected as the pretreatment method and according to the variation between different samples and the characteristic absorption band, 6 468-7 104 cm(-1) and 6 468-7 156 cm(-1) were chosen as the modeling spectra region. The confusion matrix indicated that Metoprolol Tartrate tablets could be rapidly and effectively identified by two analytical models, which were established using the spectral data collected from two instruments. For these two models, both of the sensitivity and specificity were 100%. This study confirmed that it is feasible to carry out the manufacturer identification of Metoprolol Tartrate tablets by near infrared spectroscopy. Besides, the use of Micro NIR1700 Spectrometer, which is the minimum and portable near infrared spectrometer, provides valuable insights for fast on-site drug screening.

  17. [Identification of Metoprolol Tartrate Tablets from Different Manufacturers by Different Near Infrared Spectrometers].

    PubMed

    Li, Qi-lu; Wang, Fei; Wang, Jin-feng; Zang, Heng-chang; Zhang, Hui; Jiang, Wei

    2015-10-01

    To rapidly identify Metoprolol Tartrate tablets from different manufacturers, a qualitative analysis model can be established by near infrared spectroscopy. Firstly, AntarisII Fourier-transform near infrared (FT-NIR) spectroscopy and Micro NIR1700 Spectrometer were used to collect spectral data of 66 batches of samples which come from four different manufacturers, then 44 samples of calibration set and 22 samples of validation set were acquired by random sampling. In order to build up a PLS-DA model, the first derivative with Savitzky-Golay 15 points smoothing (1d+SG15) and standard normal vitiate transformation (SNV) was selected as the pretreatment method and according to the variation between different samples and the characteristic absorption band, 6 468-7 104 cm(-1) and 6 468-7 156 cm(-1) were chosen as the modeling spectra region. The confusion matrix indicated that Metoprolol Tartrate tablets could be rapidly and effectively identified by two analytical models, which were established using the spectral data collected from two instruments. For these two models, both of the sensitivity and specificity were 100%. This study confirmed that it is feasible to carry out the manufacturer identification of Metoprolol Tartrate tablets by near infrared spectroscopy. Besides, the use of Micro NIR1700 Spectrometer, which is the minimum and portable near infrared spectrometer, provides valuable insights for fast on-site drug screening. PMID:26904845

  18. Applications Of Microspectroscopy In The Near-Infrared Region

    NASA Astrophysics Data System (ADS)

    Smith, Matthew J.; Carl, Richard T.

    1989-12-01

    The technique of infrared microspectroscopy has numerous applications in many fields including materials science, forensics, contamination analysis and biological science. The majority of these applications have been in the mid-infrared since using different spectral ranges in an FT-IR spectrometer often involve modifications to the interferometer, source and detector. However, recent advancements in infrared instrumentation have allowed rapid spectral range changes to become routine. As a result, near-infrared microspectroscopy is now a viable technique.1 The principle advantage of near-infrared microspectroscopy is the ability to analyze samples which are totally absorbing in the mid-infrared region. Most near-infrared absorbances are due to overtones or combination bands of fundamental bands and are typically one to two orders of magnitude weaker than their corresponding fundamental transitions. Thus, transmission analysis in the near-infrared can be carried out on many samples which are otherwise too thick for transmission analysis in the mid-infrared.

  19. Near-Infrared Spectra of Type Ia Supernovae

    NASA Technical Reports Server (NTRS)

    Marion, G. H.; Hoeflich, P.; Vacca, W. D.; Wheeler, J. C.

    2003-01-01

    We report near-infrared (NIR) spectroscopic observations of 12 'branch-normal' Type Ia supernovae (SNe Ia) that cover the wavelength region from 0.8 to 2.5 microns. Our sample more than doubles the number of SNe Ia with published NIR spectra within 3 weeks of maximum light. The epochs of observation range from 13 days before maximum light to 18 days after maximum light. A detailed model for a Type Ia supernovae is used to identify spectral features. The Doppler shifts of lines are measured to obtain the velocity and thus the radial distribution of elements. The NIR is an extremely useful tool to probe the chemical structure in the layers of SNe Ia ejecta. This wavelength region is optimal for examining certain products of the SNe Ia explosion that may be blended or obscured in other spectral regions. We identify spectral features from Mg II, Ca II, Si II, Fe II, Co II, Ni II, and possibly Mn II. We find no indications for hydrogen, helium, or carbon in the spectra. The spectral features reveal important clues about the physical characteristics of SNe Ia. We use the features to derive upper limits for the amount of unburned matter, to identify the transition regions from explosive carbon to oxygen burning and from partial to complete silicon burning, and to estimate the level of mixing during and after the explosion. Elements synthesized in the outer layers during the explosion appear to remain in distinct layers. That provides strong evidence for the presence of a detonation phase during the explosion as it occurs in delayed detonation or merger models. Mg II velocities are found to exceed 11,000 - 15,000 km/s, depending on the individual SNe Ia. That result suggests that burning during the explosion reaches the outermost layers of the progenitor and limits the amount of unburned material to less than 10% of the mass of the progenitor. Small residuals of unburned material are predicted by delayed detonation models but are inconsistent with pure deflagration or

  20. Near-infrared branding efficiently correlates light and electron microscopy.

    PubMed

    Bishop, Derron; Nikić, Ivana; Brinkoetter, Mary; Knecht, Sharmon; Potz, Stephanie; Kerschensteiner, Martin; Misgeld, Thomas

    2011-06-05

    The correlation of light and electron microscopy of complex tissues remains a major challenge. Here we report near-infrared branding (NIRB), which facilitates such correlation by using a pulsed, near-infrared laser to create defined fiducial marks in three dimensions in fixed tissue. As these marks are fluorescent and can be photo-oxidized to generate electron contrast, they can guide re-identification of previously imaged structures as small as dendritic spines by electron microscopy.

  1. Nano-plasmonic antennas in the near infrared regime.

    PubMed

    Berkovitch, N; Ginzburg, P; Orenstein, M

    2012-02-22

    Plasmonic nano-antennas constitute a central research topic in current science and engineering with an enormous variety of potential applications. Here we review the recent progress in the niche of plasmonic nano-antennas operating in the near infrared part of the spectrum which is important for a variety of applications. Tuning of the resonance into the near infrared regime is emphasized in the perspectives of fabrication, measurement, modeling, and analytical treatments, concentrating on the vast recent achievements in these areas.

  2. Near-infrared spectroscopic evaluation of lyophilized viral vaccine formulations.

    PubMed

    Hansen, Laurent; Beer, Thomas De; Pieters, Sigrid; Heyden, Yvan Vander; Vervaet, Chris; Remon, Jean Paul; Montenez, Jean-Pierre; Daoussi, Rim

    2013-01-01

    This article examines the applicability of near-infrared spectroscopy (NIRS) to evaluate the virus state in a freeze-dried live, attenuated vaccine formulation. Therefore, this formulation was freeze-dried using different virus volumes and after applying different pre-freeze-drying virus treatments (resulting in different virus states): (i) as used in the commercial formulation; (ii) without antigen (placebo); (iii) concentrated via a centrifugal filter device; and (iv) stressed by 96 h exposure to room temperature. Each freeze-dried product was measured directly after freeze-drying with NIR spectroscopy and the spectra were analyzed using principal component analysis (PCA). Herewith, two NIR spectral regions were evaluated: (i) the 7300-4000 cm(-1) region containing the amide A/II band which might reflect information on the coated proteins of freeze-dried live, attenuated viruses; and (ii) the C-H vibration overtone regions (10,000-7500 and 6340-5500 cm(-1) ) which might supply information on the lipid layer surrounding the freeze-dried live, attenuated viruses. The different pre-freeze-drying treated live, attenuated virus formulations (different virus states and virus volumes) resulted in different clusters in the scores plots resulting from the PCA of the collected NIR spectra. Secondly, partial least squares discriminant analysis models (PLS-DA) were developed and evaluated, allowing classification of the freeze-dried formulations according to virus pretreatment. The results of this study suggest the applicability of NIR spectroscopy for evaluating live, attenuated vaccine formulations with respect to their virus pretreatment and virus volume. PMID:24014045

  3. Feeding versus feedback in AGN from near-infrared IFU observations XI: NGC 2110

    NASA Astrophysics Data System (ADS)

    Diniz, Marlon R.; Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Winge, Claudia

    2015-10-01

    We present a two-dimensional mapping of the gas flux distributions, as well as of the gas and stellar kinematics in the inner 220 pc of the Seyfert galaxy NGC 2110, using K-band integral field spectroscopy obtained with the Gemini Near-infrared Integral Field Spectrograph at a spatial resolution of ≈24 pc and spectral resolution of ≈40 km s- 1. The H2 λ2.1218 μm emission extends over the whole field of view and is attributed to heating by X-rays from the AGN and/or by shocks, while the Brγ emission is restricted to a bipolar region extending along the south-east-north-west direction. The masses of the warm molecular gas and of the ionized gas are M_H_2≈ 1.4× 10^3 {M_{{⊙}}} and M_{H II}≈ 1.8× 10^6 {M_{{⊙}}}, respectively. The stellar kinematics present velocity dispersions reaching 250 km s-1 and a rotation pattern reaching an amplitude of 200 km s-1. The gas velocity fields present a similar rotation pattern but also additional components that we attribute to inflows and outflows most clearly observed in the molecular gas emission. The inflows are observed beyond the inner 70 pc and are associated with a spiral arm seen in blueshift to the north-east and another in redshift to the south-west. We have estimated a mass inflow rate in warm molecular gas of ≈4.6 × 10-4 M⊙ yr-1. Within the inner 70 pc, another kinematic component is observed in the H2 emission that can be interpreted as due to a bipolar nuclear outflow oriented along the east-west direction, with a mass outflow rate of ≈4.3 × 10-4 M⊙ yr-1 in warm H2.

  4. Observing Resolved Stellar Populations with the JWST Near-Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Gilbert, K. M.; Beck, T. L.; Karakla, D. M.

    2016-10-01

    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) will provide a multi-object spectroscopy (MOS) mode through the Micro-Shutter Array (MSA). Each MSA quadrant 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 over 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 of spectroscopy of individual stars in an external galaxy, and investigate the technical challenges posed by this scenario. This use case and others, including a deep galaxy survey and observations of Galactic HII regions, are guiding development of the NIRSpec user interfaces including proposal planning and pipeline calibrations.

  5. The H II regions of the irregular galaxy, NGC 3239

    SciTech Connect

    Krienke, K.; Hodge, P. Washington, University, Seattle )

    1991-03-01

    The luminosities of the 88 H II regions of NGC 3239, very likely a merging galaxy system, were measured by digital analysis of a photographic plate (20 A bandwidth filter). Despite evidence for earlier starburst activity, the present H II luminosity function is very similar to that for the LMC, including a supergiant H II region of 0.76 the luminosity of 30 Dor. The measured H II regions of NGC 3239 have an H-alpha total luminosity of 1.3 x 10 to the 40th erg/s. 13 refs.

  6. AGN from HeII: AGN host galaxy properties & demographics

    NASA Astrophysics Data System (ADS)

    Baer, Rudolf E.; Schawinski, Kevin; Weigel, Anna

    2016-01-01

    We present an analysis of HeII emitting objects classified as AGN. In a sample of 81'192 galaxies taken from the seventh data release (DR7) of the Sloan Digital Sky Survey in the redshift interval 0.02 < z < 0.05 and with r < 17 AB mag, the Baldwin, Philips & Terlevitsch 1981 method (BPT) identifies 1029 objects as active galactic nuclei. By applying an analysis using HeII λ 4686 emission lines, based on Shirazi & Binchmann 2012, we have identified an additional 283 active galactic nuclei, which were missed by the BPT method. This represents an increase of over 25 %. The characteristics of the HeII selected AGN are different from the AGN found through the PBT; the colour - mass diagram and the colour histogram both show that HeII selected AGN are bluer. This new selection technique can help inform galaxy black hole coevolution scenarios.

  7. AKARI Observation of the Sub-degree Scale Fluctuation of the Near-infrared Background

    NASA Astrophysics Data System (ADS)

    Seo, H. J.; Lee, Hyung Mok; Matsumoto, T.; Jeong, W.-S.; Lee, Myung Gyoon; Pyo, J.

    2015-07-01

    We report spatial fluctuation analysis of the sky brightness in the near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 μm. As a follow-up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000″. We found residual fluctuation over the estimated shot noise at larger angles than the angular scale of the Monitor field. The excess fluctuation of the NEP deep field smoothly connects with that of the Monitor field at angular scales of a few hundred arcseconds and extends without any significant variation to larger angular scales up to 1000″. By comparing excess fluctuations at two wavelengths, we confirm a blue spectral feature similar to the result of the Monitor field. We find that the result of this study is consistent with Spitzer Space Telescope observations at 3.6 μm. The origin of the excess fluctuation in the near-infrared background remains to be determined, but we could exclude zodiacal light, diffuse Galactic light, and unresolved faint galaxies at low redshift based on the comparison with mid- and far-infrared brightness, ground-based near-infrared images.

  8. AKARI OBSERVATION OF THE SUB-DEGREE SCALE FLUCTUATION OF THE NEAR-INFRARED BACKGROUND

    SciTech Connect

    Seo, H. J.; Lee, Hyung Mok; Lee, Myung Gyoon; Matsumoto, T.; Jeong, W.-S.; Pyo, J.

    2015-07-10

    We report spatial fluctuation analysis of the sky brightness in the near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 μm. As a follow-up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000″. We found residual fluctuation over the estimated shot noise at larger angles than the angular scale of the Monitor field. The excess fluctuation of the NEP deep field smoothly connects with that of the Monitor field at angular scales of a few hundred arcseconds and extends without any significant variation to larger angular scales up to 1000″. By comparing excess fluctuations at two wavelengths, we confirm a blue spectral feature similar to the result of the Monitor field. We find that the result of this study is consistent with Spitzer Space Telescope observations at 3.6 μm. The origin of the excess fluctuation in the near-infrared background remains to be determined, but we could exclude zodiacal light, diffuse Galactic light, and unresolved faint galaxies at low redshift based on the comparison with mid- and far-infrared brightness, ground-based near-infrared images.

  9. Comparing [C II] , HI, and CO Dynamics of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    de Blok, W. J. G.; Walter, F.; Smith, J.-D. T.; Herrera-Camus, R.; Bolatto, A. D.; Requena-Torres, M. A.; Crocker, A. F.; Croxall, K. V.; Kennicutt, R. C.; Koda, J.; Armus, L.; Boquien, M.; Dale, D.; Kreckel, K.; Meidt, S.

    2016-08-01

    The H i and CO components of the interstellar medium (ISM) are usually used to derive the dynamical mass {M}{{dyn}} of nearby galaxies. Both components become too faint to be used as a tracer in observations of high-redshift galaxies. In those cases, the 158 μm line of atomic carbon ([C ii]) may be the only way to derive {M}{{dyn}}. As the distribution and kinematics of the ISM tracer affects the determination of {M}{{dyn}}, it is important to quantify the relative distributions of H i, CO, and [C ii]. H i and CO are well-characterized observationally, however, for [C ii] only very few measurements exist. Here we compare observations of CO, H i, and [C ii] emission of a sample of nearby galaxies, drawn from the HERACLES, THINGS, and KINGFISH surveys. We find that within R 25, the average [C ii] exponential radial profile is slightly shallower than that of the CO, but much steeper than the H i distribution. This is also reflected in the integrated spectrum (“global profile”), where the [C ii] spectrum looks more like that of the CO than that of the H i. For one galaxy, a spectrally resolved comparison of integrated spectra was possible; other comparisons were limited by the intrinsic line-widths of the galaxies and the coarse velocity resolution of the [C ii] data. Using high-spectral-resolution SOFIA [C ii] data of a number of star forming regions in two nearby galaxies, we find that their [C ii] linewidths agree better with those of the CO than the H i. As the radial extent of a given ISM tracer is a key input in deriving {M}{{dyn}} from spatially unresolved data, we conclude that the relevant length-scale to use in determining {M}{{dyn}} based on [C ii] data, is that of the well-characterized CO distribution. This length scale is similar to that of the optical disk.

  10. Extended [C II] Emission in Local Luminous Infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Díaz-Santos, T.; Armus, L.; Charmandaris, V.; Stacey, G.; Murphy, E. J.; Haan, S.; Stierwalt, S.; Malhotra, S.; Appleton, P.; Inami, H.; Magdis, G. E.; Elbaz, D.; Evans, A. S.; Mazzarella, J. M.; Surace, J. A.; van der Werf, P. P.; Xu, C. K.; Lu, N.; Meijerink, R.; Howell, J. H.; Petric, A. O.; Veilleux, S.; Sanders, D. B.

    2014-06-01

    We present Herschel/PACS observations of extended [C II] 157.7 μm line emission detected on ~1-10 kpc scales in 60 local luminous infrared galaxies (LIRGs) from the Great Observatories All-sky LIRG Survey. We find that most of the extra-nuclear emission show [C II]/FIR ratios >=4 × 10-3, larger than the mean ratio seen in the nuclei, and similar to those found in the extended disks of normal star-forming galaxies and the diffuse interstellar medium of our Galaxy. The [C II] "deficits" found in the most luminous local LIRGs are therefore restricted to their nuclei. There is a trend for LIRGs with warmer nuclei to show larger differences between their nuclear and extra-nuclear [C II]/FIR ratios. We find an anti-correlation between [C II]/FIR and the luminosity surface density, ΣIR, for the extended emission in the spatially resolved galaxies. However, there is an offset between this trend and that found for the LIRG nuclei. We use this offset to derive a beam filling-factor for the star-forming regions within the LIRG disks of ~6% relative to their nuclei. We confront the observed trend to photo-dissociation region models and find that the slope of the correlation is much shallower than the model predictions. Finally, we compare the correlation found between [C II]/FIR and ΣIR with measurements of high-redshift starbursting IR-luminous galaxies.

  11. Simulating Future Near-Infrared Grism Spectroscopy Using The WFC3 Infrared Spectroscopic Parallels (WISP)

    NASA Astrophysics Data System (ADS)

    Colbert, James W.; Teplitz, H. I.; Atek, H.; Bunker, A. J.; Rafelski, M.; Scarlata, C.; Ross, N.; Malkan, M. A.; Bedregal, A.; Dominguez, A.; Dressler, A.; Henry, A. L.; Martin, C. L.; Masters, D.; McCarthy, P. J.; Siana, B. D.

    2014-01-01

    We present near-infrared emission line counts and luminosity functions from the HST WFC3 Infrared Spectroscopic Parallels (WISP) program for 29 fields observed using both the G102 and G141 grism. Using these derived emission line counts we make predictions for future space missions, like WFIRST, that will make extensive use of slitless grism spectroscopy in the near-IR over large areas of sky. The WISP survey is sensitive to fainter flux levels (3-5x10^-17 ergs/s/cm2) than the near-infrared grism missions aimed at baryonic acoustic oscillation cosmology (1-4x10^-16 ergs/s/cm2), allowing us to both investigate the fainter emission lines the large area surveys will be missing and make count predictions for the deeper grism pointings that are likely to be done over smaller areas. Cumulative number counts of 0.7galaxies reach 10,000 square degrees above an H-alpha flux of 2x10^{-16} ergs/s/cm2. Galaxies with low H-alpha/[OIII] ratios are very rare at the brighter fluxes that future near-infrared grism surveys will probe; our survey finds no galaxies with H-alpha/[OIII < 0.95 that have H-alpha flux greater than 3x10^-16 ergs/s/cm2. We find good agreement between our derived luminosity functions and those from narrow band H-alpha surveys, like those of HiZELS (Sobral et al. 2013) and New Halpha (Ly et. 2011). The evolution in both the H-alpha luminosity function from z=0.3-1.5 and the [OIII] luminosity function from z=0.7-2.3 is almost entirely in the L* parameter, which steadily increases with redshift over those ranges. We will also present simulations of future large area near-infrared grism spectroscopy, based on the observed distributions of emission line fluxes, galaxy sizes, redshifts, H-alpha/[OIII] ratios, and equivalent widths seen in the WISP survey.

  12. A Near-infrared Survey of the Rosette Complex: Clues of Early Cluster Evolution

    NASA Astrophysics Data System (ADS)

    Román-Zúñiga, Carlos G.; Lada, Elizabeth A.; Ferreira, Bruno

    2008-05-01

    The majority of stars in our galaxy are born in embedded clusters, which can be considered the fundamental units of star formation. We have recently surveyed the star forming content of the Rosette Complex using FLAMINGOS in order to investigate the properties of its embedded clusters. We discuss the results of our near-infrared imaging survey. In particular, we on the first evidence for the early evolution and expansion of the embedded clusters. In addition we present data suggesting a temporal sequence of cluster formation across the cloud and discuss the influence of the HII region on the star forming history of the Rosette.

  13. Starburst in the Interacting HII Galaxy II Zw 40 and in Non-Interacting HII Galaxies

    NASA Astrophysics Data System (ADS)

    Telles, E.

    2010-06-01

    In this poster, I summarize the results of our integral field spectroscopic observations of the nearby prototype of HII galaxies, II Zw 40. Observations with GMOS-IFU on GEMINI-North in the optical allowed us to make a detailed kinematic picture of the central starburst, while SINFONI with adaptive optics on the ESO-VLT gave us a near-IR view of the interplay between the ISM phases. Here, I also address the question that not all starbursts require an external trigger such as a galaxy-galaxy encounter, as it seems to be the case for a fraction of low luminosity HII galaxies. We speculate that these may form stars spontaneously like "popcorn in a pan".

  14. Probing outflows in z = 1 ∼ 2 galaxies through Fe II/Fe II* multiplets

    SciTech Connect

    Tang, Yuping; Giavalisco, Mauro; Guo, Yicheng

    2014-10-01

    We report on a study of the 2300-2600 Å Fe II/Fe II* multiplets in the rest-UV spectra of star-forming galaxies at 1.0 < z < 2.6 as probes of galactic-scale outflows. We extracted a mass-limited sample of 97 galaxies at z ∼ 1.0-2.6 from ultra-deep spectra obtained during the GMASS spectroscopic survey in the GOODS South field with the Very Large Telescope and FORS2. We obtain robust measures of the rest equivalent width of the Fe II absorption lines down to a limit of W{sub r} > 1.5 Å and of the Fe II* emission lines to W{sub r} > 0.5 Å. Whenever we can measure the systemic redshift of the galaxies from the [O II] emission line, we find that both the Fe II and Mg II absorption lines are blueshifted, indicating that both species trace gaseous outflows. We also find, however, that the Fe II gas has generally lower outflow velocity relative to that of Mg II. We investigate the variation of Fe II line profiles as a function of the radiative transfer properties of the lines, and find that transitions with higher oscillator strengths are more blueshifted in terms of both line centroids and line wings. We discuss the possibility that Fe II lines are suppressed by stellar absorptions. The lower velocities of the Fe II lines relative to the Mg II doublet, as well as the absence of spatially extended Fe II* emission in two-dimensional stacked spectra, suggest that most clouds responsible for Fe II absorption lie close (3 ∼ 4 kpc) to the disks of galaxies. We show that the Fe II/Fe II* multiplets offer unique probes of the kinematic structure of galactic outflows.

  15. New and Better Near-Infrared Detectors for JWST Near Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Mott, D. Brent; Wen, Yiting; Linder, Don; Greenhouse, Matthew A.; Hill, Robert J.

    2014-01-01

    ESA and NASA recently selected two 5 m cutoff Teledyne H2RG sensor chip assemblies (SCA) for flight on the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These HgCdTe SCAs incorporate Teledynes improved barrier layer design that eliminates the degradation that affected earlier JWST H2RGs(Rauscher et al. 2012a). The better indium barrier, together with other design changes, has improved the performance and reliability of JWSTs SCAs. In this article, we describe the measured performance characteristics that most directly affect scientific observations including read noise, total noise, dark current, quantum efficiency (QE), and image persistence. As part of measuring QE, we measured the quantum yield as a function of photon energy,, and found that it exceeds unity for photon energies E (2.65.2) Eg, where Eg is the HgCdTe bandgap energy. This corresponds to. 2 m for NIRSpecs 5 m cutoff HgCdTe. Our measurements agree well with a previous measurement by McCullough et al. (2008) for. 1.3. For 1.3, we find a slower increase in with photon energy than McCullough et al. did. However, and as McCullough et al. note, their two state model of the yield process is not valid for large 1.

  16. Near-infrared (J, H, K) imaging of Herbig Ae/Be stars

    NASA Astrophysics Data System (ADS)

    Li, Wenbin; Evans, Neal J., II; Harvey, Paul M.; Colome, Cecilia

    1994-09-01

    Near-infrared (J, H, K) images were obtained for 16 Herbig Ae/Be stars. The primary goal was to determine the contributions by circumstellar nebulae and nearby sources to near-infrared photometry carried out with large beams. Quasi-simultaneous photometric results were obtained with small apertures. The emission toward five Herbig Ae/Be stars is extended, including all four Group II sources in our sample (Hillebrand et al. 1992); 13 objects have nearby sources (within 10 sec separation). However, the extended emission and nearby sources are too faint to affect previous photometry significantly. The surface brightness profiles of most of the nebulae can be explained by reflection nebulae which scatter the light from the central star/disk systems with single, isotropic scattering processes. The exception is Par 21, which may require emission from very small grains. The color-color diagram, making use of our new photometry, essentially agrees with the results of Lada & Adams (1992). The Group II objects in our sample tend to have extended emission more frequently than do Group I objects, supporting the suggestion of Hillebrand et al. that Group II sources are more affected by circumstellar envelopes. However, most of the near-infrared emission comes from the central (less than or = 6 sec) regions. This upper limit is still much larger than the expected size of accretion disks. Possible envelope effects could not be ruled out for most Herbig Ae/Be stars with unresolved emission. The images do not clearly favor very small, thermally emitting grains as the origin of the near-infrared emission. The problem still exists of how to explain the observed peaks near 3 sec in the spectral energy distributions of Herbig Ae/Be stars. The possible effects of envelopes and companions are addressed.

  17. Detecting Galaxy Formation with He II Cooling Radiation

    NASA Astrophysics Data System (ADS)

    Yang, Yujin; Zabludoff, Ann; Davé, Romeel; Eisenstein, Daniel

    2006-08-01

    Galaxies obtain material to form their stars from the intergalactic medium, but direct observations of such accretion do not yet exist. Motivated by our theoretical work, we propose the first direct search for gravitational cooling radiation arising from the infall of gas into forming galaxies at z=3. While ``Lyα blobs'' are the best candidates for gas-accreting galaxies at high redshift, and are therefore the focus of our proposed study, their nature remains unknown due to intrinsic difficulties in interpreting their Lyα emission. Here, we propose to survey 10 of the Lyα blobs from the Matsuda et al. sample for He II. Compared to Lyα, Heha is optically thin, less sensitive to the UV background, and less contaminated by the recombination lines from star-forming galaxies, making it an ideal diagnostic line to uncover the processes by which galaxies acquire their baryons. This proposal is a resubmission in which we have explicitly addressed the concerns raised by the TAC last year. This project represents a new approach, which has the potential to revolutionize studies of galaxy formation.

  18. Counting near-infrared single-photons with 95% efficiency.

    PubMed

    Lita, Adriana E; Miller, Aaron J; Nam, Sae Woo

    2008-03-01

    Single-photon detectors operating at visible and near-infrared wavelengths with high detection efficiency and low noise are a requirement for many quantum-information applications. Superconducting transition-edge sensors (TESs) are capable of detecting visible and near-infrared light at the single-photon level and are capable of discriminating between one- and two-photon absorption events; however these capabilities place stringent design requirements on the TES heat capacity, thermometry, and optical detection efficiency. We describe the fabrication and evaluation of a fiber-coupled, photon-number-resolving TES detector optimized for absorption at 1550 and 1310 nm wavelengths. The measured system detection efficiency at 1556 nm is 95 % +/- 2 %, which to our knowledge is the highest system detection efficiency reported for a near-infrared single-photon detector. PMID:18542389

  19. Near infrared spectroscopy of stearic acid adsorbed on montmorillonite.

    PubMed

    Lu, Longfei; Cai, Jingong; Frost, Ray L

    2010-03-01

    The adsorption of stearic acid on both sodium montmorillonites and calcium montmorillonites has been studied by near infrared spectroscopy complimented with infrared spectroscopy. Upon adsorption of stearic acid on Ca-Mt additional near infrared bands are observed at 8236 cm(-1) and is assigned to an interaction of stearic acid with the water of hydration. Upon adsorption of the stearic acid on Na-Mt, the NIR bands are now observed at 5671, 5778, 5848 and 5912 cm(-1) and are assigned to the overtone and combination bands of the CH fundamentals. Additional bands at 4177, 4250, 4324, 4337, 4689 and 4809 cm(-1) are attributed to CH combination bands resulting from the adsorption of the stearic acid. Stearic acid is used as a model molecule for adsorption studies. The application of near infrared spectroscopy to the study of this adsorption proved most useful. PMID:20071218

  20. Near-infrared time-resolved spectroscopy of the cataclysmic variable YY Draconis

    SciTech Connect

    Mateo, M.; Szkody, P.; Garnavich, P. Washington Univ., Seattle )

    1991-03-01

    Time-resolved near-infrared (8100-8600 A) spectrophotometry and Johnson B-band CCD photometry of the cataclysmic binary YY Dra are presented. The spectra show the presence of the Na I doublet in absorption from the secondary, as well as sharp and broad Ca II emission lines. The sharp Ca II emission lines appear to originate on or near the secondary star because they are visible only during superior conjunction of the secondary star, their radial velocities vary in phase with the Na I absorption lines, and their K-velocity is considerably smaller than observed for the Na I lines. The radial velocity variation of the Na I near-infrared doublet yield an orbital period for YY Dra of P = 0.164988 + or - 0.00023 days. A spectral type of dM 4 + or - 1 for the secondary star is deduced based on the strength of its near-infrared spectral features. The distance to YY Dra is 155 + or - 35 pc based on an application of Bailey's method. 56 refs.

  1. A Pressure Anomaly for H II Regions in Irregular Galaxies

    NASA Astrophysics Data System (ADS)

    Elmegreen, Bruce G.; Hunter, Deidre A.

    2000-09-01

    The pressures of giant H II regions in six dwarf irregular galaxies are found to be a factor of ~10 larger than the average pressures of the corresponding galaxy disks, obtained from the stellar and gaseous column densities. This is unlike the situation for spiral galaxies, where these two pressures are approximately equal. Either the H II regions in these dwarfs are all so young that they are still expanding, or there is an unexpected source of disk self-gravity that increases the background pressure. We consider first whether any additional self-gravity might come from disk dark matter that either is cold H2 gas in diffuse or self-gravitating clouds with weak CO emission, or is the same material as the halo dark matter inferred from rotation curves. The H2 solution is possible because cold molecular clouds would be virtually invisible in existing surveys if they were also CO-weak from the low metal abundances in these galaxies. Cosmological dark matter might be possible too because of the relatively large volume fraction occupied by the disk within the overall galaxy potential. There is a problem with both of these solutions, however: the vertical scale heights inferred for irregular galaxies are consistent with the luminous matter alone. The amount of disk dark matter that is required to explain the high H II region pressures would give gas and stellar scale heights that are too small. The anomalous pressures in star-forming regions are more likely the result of local peaks in the gravitational field that come from large gas concentrations. These peaks also explain the anomalously low average column density thresholds for star formation that were found earlier for irregular galaxies, and they permit the existence of a cool H I phase as the first step toward dense molecular cores. The evidence for concentrations of H I in regions of star formation is summarized; the peak column densities are shown to be consistent with local pressure equilibrium for the H II

  2. Near-infrared extinction with discretised stellar colours

    NASA Astrophysics Data System (ADS)

    Juvela, M.; Montillaud, J.

    2016-01-01

    Context. Near-infrared (NIR) extinction remains one of the most reliable methods of measuring the column density of dense interstellar clouds. Extinction can be estimated using the reddening of the light of background stars. Several methods exist (e.g., NICE, NICER, NICEST, GNICER) to combine observations of several NIR bands into extinction maps. Aims: We present a new method of estimating extinction based on NIR multiband observations and examine its performance. Methods: Our basic method uses a discretised version of the distribution of intrinsic stellar colours directly. The extinction of individual stars and the average over a resolution element are estimated with Markov chain Monte Carlo (MCMC) methods. Several variations of the basic method are tested, and the results are compared to NICER calculations. Results: In idealised settings or when photometric errors are large, the results of the new method are very close to those of NICER. Clear advantages can be seen when the distribution of intrinsic colours cannot be described well with a single covariance matrix. The MCMC framework makes it easy to consider additional effects such as those of completeness limits and contamination by galaxies or foreground stars. A priori information about relative column density variations at sub-beam scales can result in a significant increase in accuracy. For observations of high photometric precision, the results could be further improved by considering the magnitude dependence of the intrinsic colours. Conclusions: The MCMC computations are time-consuming, but the calculation of large extinction maps is already practical. The same methods can be used with direct optimisation, with significantly less computational work. Faster methods, like NICER, perform very well in many cases even when the basic assumptions no longer hold. The new methods are useful mostly when photometric errors are small, the distribution of intrinsic colours is well known, or one has prior knowledge

  3. Near-infrared face recognition utilizing open CV software

    NASA Astrophysics Data System (ADS)

    Sellami, Louiza; Ngo, Hau; Fowler, Chris J.; Kearney, Liam M.

    2014-06-01

    Commercially available hardware, freely available algorithms, and authors' developed software are synergized successfully to detect and recognize subjects in an environment without visible light. This project integrates three major components: an illumination device operating in near infrared (NIR) spectrum, a NIR capable camera and a software algorithm capable of performing image manipulation, facial detection and recognition. Focusing our efforts in the near infrared spectrum allows the low budget system to operate covertly while still allowing for accurate face recognition. In doing so a valuable function has been developed which presents potential benefits in future civilian and military security and surveillance operations.

  4. Breast phantom for mammary tissue characterization by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Miranda, D. A.; Cristiano, K. L.; Gutiérrez, J. C.

    2013-11-01

    Breast cancer is a disease associated to a high morbidity and mortality in the entire world. In the study of early detection of breast cancer the development of phantom is so important. In this research we fabricate a breast phantom using a ballistic gel with special modifications to simulate a normal and abnormal human breast. Optical properties of woman breast in the near infrared region were modelled with the phantom we developed. The developed phantom was evaluated with near infrared spectroscopy in order to study its relation with breast tissue. A good optical behaviour was achieved with the model fabricated.

  5. Estimation of spreading fire geometrical characteristics using near infrared stereovision

    NASA Astrophysics Data System (ADS)

    Rossi, L.; Toulouse, T.; Akhloufi, M.; Pieri, A.; Tison, Y.

    2013-03-01

    In fire research and forest firefighting, there is a need of robust metrological systems able to estimate the geometrical characteristics of outdoor spreading fires. In recent years, we assist to an increased interest in wildfire research to develop non destructive techniques based on computer vision. This paper presents a new approach for the estimation of fire geometrical characteristics using near infrared stereovision. Spreading fire information like position, rate of spread, height and surface, are estimated from the computed 3D fire points. The proposed system permits to track fire spreading on a ground area of 5mx10m. Keywords: near infrared, stereovision, spreading fire, geometrical characteristics

  6. Flamingos near-infrared study of the Serpens cloud

    NASA Astrophysics Data System (ADS)

    Hasan, Priya

    We present the results of a deep near-infrared imaging survey of the Serpens Cloud made with FLAMINGOS at the 2.1 m telescope at Kitt Peak National Observatory. We study the distribution of young embedded sources using the nearest neighbor method applied to a carefully selected sample of near-infrared excess (NIRX) stars that trace the latest episode of star formation in the complex. Our analysis finds the existence of six clusters, of which three are new in the molecular cloud. We determined a median age for the cluster to be 1-2 Myr at a mean distance of 300 pc.

  7. About the emission line sequence of H II galaxies

    NASA Astrophysics Data System (ADS)

    Stasińska, G.; Izotov, Y.

    2003-09-01

    We consider 400 H II galaxies in which the oxygen abundances were obtained by electron temperature based methods. We split the sample in three metallicity bins. In each bin, a narrow sequence is found not only in pure emission line ratio diagrams but also in terms of H beta equivalent width, indicating the existence of an evolutionary sequence. Our diagrams show unambiguously the existence of an evolution on a timescale of a few Myr. We compare the observed sequences with photoionization models of appropriate metallicity. In order to understand the evolution of H II galaxies one needs to consider the evolution of the gas as well as that of the stars. The observations require EW(H beta ) to decrease more rapidly than predicted by the passive evolution of a starburst. A photoionized adiabatic expanding bubble with a covering factor decreasing with time reproduces most diagrams. However, the question of the heating of H II galaxies and the origin of the nebular He II lambda 4686 emission are not settled. We find evidence for self-enrichment in nitrogen on a time scale of several Myr.

  8. Constructing mock catalogues for the REFLEX II galaxy cluster sample

    NASA Astrophysics Data System (ADS)

    Balaguera-Antolínez, A.; Sánchez, Ariel G.; Böhringer, H.; Collins, C.

    2012-09-01

    We describe the construction of a suite of galaxy cluster mock catalogues from N-body simulations, based on the properties of the new ROSAT-ESO Flux Limited X-Ray (REFLEX II) galaxy cluster catalogue. Our procedure is based on the measurements of the cluster abundance, and involves the calibration of the underlying scaling relation linking the mass of dark matter haloes to the cluster X-ray luminosity determined in the ROSAT energy band 0.1-2.4 keV. In order to reproduce the observed abundance in the luminosity range probed by the REFLEX II X-ray luminosity function [0.01 < LX/(1044 erg s-1 h-2) < 10], a mass-X-ray luminosity relation deviating from a simple power law is required. We discuss the dependence of the calibration of this scaling relation on the X-ray luminosity and the definition of halo masses and analyse the one- and two-point statistical properties of the mock catalogues. Our set of mock catalogues provides samples with self-calibrated scaling relations of galaxy clusters together with inherent properties of flux-limited surveys. This makes them a useful tool to explore different systematic effects and statistical methods involved in constraining both astrophysical and cosmological information from present and future galaxy cluster surveys.

  9. Observations of Resolved Stellar Populations with the JWST Near Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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 over 1 to 5 micrometers will open new parameter space for studies of galaxies and resolved stellar populations alike. We present a NIRSpec MSA observing scenario for obtaining spectroscopy of individual stars in external galaxies. 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 discuss how this and other use cases are being used to guide development of the NIRSpec user interfaces, including proposal planning and pipeline calibrations.

  10. A Search for a Near-Infrared Halo Around NGC 4565

    NASA Technical Reports Server (NTRS)

    Uemizu, Kazunori; Bock, James J.; Kawada, Mitsunobu; Lange, Andrew E.; Matsumoto, Toshio; Watabe, Toyoki; Yost, Sarah A.

    1998-01-01

    We present a near-infrared (3.5-5 micron) search for the integrated emission from low-mass stars and/or brown dwarfs in the halo of the nearby edge-on spiral galaxy NGC 4565. The observation was made with a liquid-helium-cooled rocket-borne telescope using a 256 x 256 InSb array with a pixel scale of 17". Images of NGC 4565 were successfully obtained with sensitivity near the natural background limit. Our search reveals no evidence of a faint halo around the galaxy, in contrast with the previous reports of a halo around NGC 5907. The lower limit of the mass-to-light ratio for the halo of NGC 4565 is 260 (2 delta) in solar units at 3.5-5 microns. This implies that hydrogen-burning stars do not contribute significantly to the mass of the dark halo in NGC 4565.

  11. The EMIR Near-Infrared Multi-Object Spectrograph for GTC

    NASA Astrophysics Data System (ADS)

    Balcells, M.

    1998-06-01

    EMIR is a near-infrared (NIR) multi-object spectrograph (MOS) proposed for first-generation common user instrument of the Gran Telescopio Canarias GTC. It has three observing modes: imaging, multiobject spectroscopy and integral-field spectroscopy, in the NIR Z, J, H and K bands. The design uses cryogenic multislit masks to allow simultaneous spectroscopy of up to approximately 50 objects. The spectral resolution R=5000 allows for effective "see through" the OH line forest that dominates the J and H sky backgrounds. EMIR addresses one of the fundamental goals of large telescopes, the spectroscopy of large quantities of faint sources. Science applications include young stellar objects embedded in molecular clouds, brown dwarfs, stellar clusters, resolved population in external galaxies and distant galaxies. EMIR is being designed by a consortium of Spanish, UK and French Institutes. Project updates and information will be posted at http://www.ucm.es/info/emir/.

  12. 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.

  13. Cotton micronaire measurements by small portable near infrared (nir) analyzers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A key quality and processing parameter for cotton fiber is micronaire, which is a function of the fiber’s maturity and fineness. Near Infrared (NIR) spectroscopy has previously shown the ability to measure micronaire, primarily in the laboratory and using large, research-grade laboratory NIR instru...

  14. Social Perception in Infancy: A Near Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Lloyd-Fox, Sarah; Blasi, Anna; Volein, Agnes; Everdell, Nick; Elwell, Claire E.; Johnson, Mark H.

    2009-01-01

    The capacity to engage and communicate in a social world is one of the defining characteristics of the human species. While the network of regions that compose the social brain have been the subject of extensive research in adults, there are limited techniques available for monitoring young infants. This study used near infrared spectroscopy to…

  15. Comparative hazard evaluation of near-infrared diode lasers.

    PubMed

    Marshall, W J

    1994-05-01

    Hazard evaluation methods from various laser protection standards differ when applied to extended-source, near-infrared lasers. By way of example, various hazard analyses are applied to laser training systems, which incorporate diode lasers, specifically those that assist in training military or law enforcement personnel in the proper use of weapons by simulating actual firing by the substitution of a beam of near-infrared energy for bullets. A correct hazard evaluation of these lasers is necessary since simulators are designed to be directed toward personnel during normal use. The differences among laser standards are most apparent when determining the hazard class of a laser. Hazard classification is based on a comparison of the potential exposures with the maximum permissible exposures in the 1986 and 1993 versions of the American National Standard for the Safe Use of Lasers, Z136.1, and the accessible emission limits of the federal laser product performance standard. Necessary safety design features of a particular system depend on the hazard class. The ANSI Z136.1-1993 standard provides a simpler and more accurate hazard assessment of low-power, near-infrared, diode laser systems than the 1986 ANSI standard. Although a specific system is evaluated, the techniques described can be readily applied to other near-infrared lasers or laser training systems. PMID:8175359

  16. Detecting Counterfeit Antimalarial Tablets by Near-Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discrim...

  17. Mars: Near-infrared comparative spectroscopy during the 1986 opposition

    NASA Technical Reports Server (NTRS)

    Bell, James F., III; Mccord, Thomas B.

    1987-01-01

    Near-infrared spectral observations of Mars during the 1986 opposition were performed at the Mauna Kea Observatory utilizing the University of Hawaii's 88 inch telescope. Spectra were obtained of several Martian locations using a continuously variable filter (CVF) spectrometer with a resolution of 1.25 percent. Spot-to-spot ratios were produced between spectra taken in different geological regions.

  18. Comparative hazard evaluation of near-infrared diode lasers.

    PubMed

    Marshall, W J

    1994-05-01

    Hazard evaluation methods from various laser protection standards differ when applied to extended-source, near-infrared lasers. By way of example, various hazard analyses are applied to laser training systems, which incorporate diode lasers, specifically those that assist in training military or law enforcement personnel in the proper use of weapons by simulating actual firing by the substitution of a beam of near-infrared energy for bullets. A correct hazard evaluation of these lasers is necessary since simulators are designed to be directed toward personnel during normal use. The differences among laser standards are most apparent when determining the hazard class of a laser. Hazard classification is based on a comparison of the potential exposures with the maximum permissible exposures in the 1986 and 1993 versions of the American National Standard for the Safe Use of Lasers, Z136.1, and the accessible emission limits of the federal laser product performance standard. Necessary safety design features of a particular system depend on the hazard class. The ANSI Z136.1-1993 standard provides a simpler and more accurate hazard assessment of low-power, near-infrared, diode laser systems than the 1986 ANSI standard. Although a specific system is evaluated, the techniques described can be readily applied to other near-infrared lasers or laser training systems.

  19. Near-infrared spectroscopic tissue imaging for medical applications

    DOEpatents

    Demos, Stavros; Staggs, Michael C.

    2006-12-12

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  20. Near-infrared spectroscopic tissue imaging for medical applications

    DOEpatents

    Demos; Stavros , Staggs; Michael C.

    2006-03-21

    Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

  1. Near-infrared observations of PSR J1357-6429

    NASA Astrophysics Data System (ADS)

    Zyuzin, D.; Zharikov, S.; Shibanov, Yu.; Danilenko, A.; Mennickent, R. E.; Kirichenko, A.

    2016-01-01

    PSR J1357-6429 is a young radio pulsar that has been detected in the X-ray and γ-ray bands. We present high spatial resolution near-infrared imaging of the pulsar field in the J, H and Ks bands obtained using the VLT/NaCo with the Adaptive Optic system. We found a faint source at the most precise pulsar radio position, which we propose as the pulsar near-infrared counterpart candidate. It is confidently detected in the J and Ks bands, with J = 23.51 ± 0.24 and Ks = 21.82 ± 0.25. There is a hint of the source in the H band, with an upper limit H > 22.8. The dereddened source fluxes are compatible with the extrapolation of the pulsar X-ray spectrum towards the near-infrared. If the candidate is the true counterpart, this property means that PSR J1357-6429 would be similar to the nearby middle-age pulsar PSR B0656+14. In this case, both pulsars demonstrate an unusually high near-infrared efficiency relative to the X-ray efficiency as compared with other pulsars detected in these two ranges.

  2. False-color image of the near-infrared sky as seen by the DIRBE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    False-color image of the near-infrared sky as seen by the DIRBE. Data at 1.25, 2.2, and 3.5 Aum wavelengths are represented respectively as blue, green and red colors. The image is presented in Galactic coordinates, with the plane of the Milky Way Galaxy horizontal across the middle and the Galactic center at the center. The dominant sources of light at these wavelengths are stars within our Galaxy. The image shows both the thin disk and central bulge populations of stars in our spiral galaxy. Our Sun, much closer to us than any other star, lies in the disk (which is why the disk appears edge-on to us) at a distance of about 28,000 light years from the center. The image is redder in directions where there is more dust between the stars absorbing starlight from distant stars. This absorption is so strong at visible wavelengths that the central part of the Milky Way cannot be seen. DIRBE data will facilitate studies of the content, energetics and large scale structure of the Galaxy, as well as the nature and distribution of dust within the Solar System. The data also will be studied for evidence of a faint, uniform infrared background, the residual radiation from the first stars and galaxies formed following the Big Bang.

  3. STELLAR KINEMATICS OF THE ANDROMEDA II DWARF SPHEROIDAL GALAXY

    SciTech Connect

    Ho, Nhung; Geha, M.; Tollerud, E.; Munoz, R. R.; Guhathakurta, P.; Gilbert, K. M.; Bullock, J.; Beaton, R. L.; Majewski, S. R. E-mail: marla.geha@yale.edu

    2012-10-20

    We present kinematical profiles and metallicity for the M31 dwarf spheroidal (dSph) satellite galaxy Andromeda II (And II) based on Keck DEIMOS spectroscopy of 531 red giant branch stars. Our kinematical sample is among the largest for any M31 satellite and extends out to two effective radii (r {sub eff} = 5.'3 = 1.1 kpc). We find a mean systemic velocity of -192.4 {+-} 0.5 km s{sup -1} and an average velocity dispersion of {sigma} {sub v} = 7.8 {+-} 1.1 km s{sup -1}. While the rotation velocity along the major axis of And II is nearly zero (<1 km s{sup -1}), the rotation along the minor axis is significant with a maximum rotational velocity of v {sub max} = 8.6 {+-} 1.8 km s{sup -1}. We find a kinematical major axis, with a maximum rotational velocity of v {sub max} = 10.9 {+-} 2.4 km s{sup -1}, misaligned by 67 Degree-Sign to the isophotal major axis. And II is thus the first dwarf galaxy with evidence for nearly prolate rotation with a v {sub max}/{sigma} {sub v} = 1.1, although given its ellipticity of {epsilon} = 0.10, this object may be triaxial. We measured metallicities for a subsample of our data, finding a mean metallicity of [Fe/H] = -1.39 {+-} 0.03 dex and an internal metallicity dispersion of 0.72 {+-} 0.03 dex. We find a radial metallicity gradient with metal-rich stars more centrally concentrated, but do not observe a significant difference in the dynamics of the two metallicity populations. And II is the only known dwarf galaxy to show minor axis rotation, making it a unique system whose existence offers important clues on the processes responsible for the formation of dSphs.

  4. The REFLEX II galaxy cluster survey: power spectrum analysis

    NASA Astrophysics Data System (ADS)

    Balaguera-Antolínez, A.; Sánchez, Ariel G.; Böhringer, H.; Collins, C.; Guzzo, L.; Phleps, S.

    2011-05-01

    We present the power spectrum of galaxy clusters measured from the new ROSAT-ESO Flux-Limited X-Ray (REFLEX II) galaxy cluster catalogue. This new sample extends the flux limit of the original REFLEX catalogue to 1.8 × 10-12 erg s-1 cm-2, yielding a total of 911 clusters with ≥94 per cent completeness in redshift follow-up. The analysis of the data is improved by creating a set of 100 REFLEX II-catalogue-like mock galaxy cluster catalogues built from a suite of large-volume Λ cold dark matter (ΛCDM) N-body simulations (L-BASICC II). The measured power spectrum is in agreement with the predictions from a ΛCDM cosmological model. The measurements show the expected increase in the amplitude of the power spectrum with increasing X-ray luminosity. On large scales, we show that the shape of the measured power spectrum is compatible with a scale-independent bias and provide a model for the amplitude that allows us to connect our measurements with a cosmological model. By implementing a luminosity-dependent power-spectrum estimator, we observe that the power spectrum measured from the REFLEX II sample is weakly affected by flux-selection effects. The shape of the measured power spectrum is compatible with a featureless power spectrum on scales k > 0.01 h Mpc-1 and hence no statistically significant signal of baryonic acoustic oscillations can be detected. We show that the measured REFLEX II power spectrum displays signatures of non-linear evolution.

  5. The dynamics and energetics of FR-II radio galaxies

    NASA Astrophysics Data System (ADS)

    Harwood, Jeremy; Morganti, Raffaella; Hardcastle, Martin; Croston, J.

    2016-01-01

    Determining the shape of the energy spectrum for an electron population can often give key insights into the underlying physics of a radio source. In principle, a region emitting via synchrotron radiation will preferentially cool higher energy electrons leading to a steeper, more strongly curved spectrum in older regions of plasma. Models of this so-called spectral aging have become a commonly used tool when describing the processes involved in emission from the lobes of FR-II radio galaxies; however, the lack of high resolution, broad-bandwidth observations has historically meant the details of these spectra have remained largely unexplored on small spatial scales. The broad-bandwidth capabilities of telescopes such as the JVLA, LOFAR, e-MERLIN and ultimately the SKA, will mean that the spectrum of any given source can be determined within the bandwidth of any given observation, producing a detailed spectral shape. This type of detailed spectral analysis is therefore set to become standard practice when dealing with any new broadband radio observations.In this talk, we provide details of the Broadband Radio Astronomy ToolS (BRATS) software package that uses innovative techniques to analyze this new generation of radio data. Through the application of BRATS to LOFAR and JVLA observations, we present results from our latest investigations into the dynamics and energetics of nearby FR-II radio galaxies and their spectral structure on small spatial scales. We go on to discuss how these new findings impact upon our current understanding of the underlying physics of FR-II radio galaxies and, ultimately, their impact of galaxy evolution as a whole.

  6. THE NEAR-INFRARED BACKGROUND INTENSITY AND ANISOTROPIES DURING THE EPOCH OF REIONIZATION

    SciTech Connect

    Cooray, Asantha; Gong Yan; Smidt, Joseph; Santos, Mario G.

    2012-09-01

    A fraction of the extragalactic near-infrared (near-IR) background light involves redshifted photons from the ultraviolet (UV) emission from galaxies present during reionization at redshifts above 6. The absolute intensity and the anisotropies of the near-IR background provide an observational probe of the first-light galaxies and their spatial distribution. We estimate the extragalactic background light intensity during reionization by accounting for the stellar and nebular emission from first-light galaxies. We require the UV photon density from these galaxies to generate a reionization history that is consistent with the optical depth to electron scattering from cosmic microwave background measurements. We also require the bright-end luminosity function (LF) of galaxies in our models to reproduce the measured Lyman-dropout LFs at redshifts of 6-8. The absolute intensity is about 0.1-0.4 nW m{sup -2} sr{sup -1} at the peak of its spectrum at {approx}1.1 {mu}m. We also discuss the anisotropy power spectrum of the near-IR background using a halo model to describe the galaxy distribution. We compare our predictions for the anisotropy power spectrum to existing measurements from deep near-IR imaging data from Spitzer/IRAC, Hubble/NICMOS, and AKARI. The predicted rms fluctuations at tens of arcminute angular scales are roughly an order of magnitude smaller than the existing measurements. While strong arguments have been made that the measured fluctuations do not have an origin involving faint low-redshift galaxies, we find that measurements in the literature are also incompatible with galaxies present during the era of reionization. The measured near-IR background anisotropies remain unexplained with an unknown origin.

  7. CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY

    SciTech Connect

    Grogin, Norman A.; Ferguson, Henry C.; Koekemoer, Anton M.; Brown, Thomas M.; Casertano, Stefano; Kocevski, Dale D.; Faber, S. M.; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Cassata, Paolo; Castellano, Marco; Challis, Peter; Chary, Ranga-Ram; and others

    2011-12-01

    The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over the approximate redshift (z) range 8-1.5. It will image >250,000 distant galaxies using three separate cameras on the Hubble Space Telescope, from the mid-ultraviolet to the near-infrared, and will find and measure Type Ia supernovae at z > 1.5 to test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with extensive ancillary data. The use of five widely separated fields mitigates cosmic variance and yields statistically robust and complete samples of galaxies down to a stellar mass of 10{sup 9} M{sub Sun} to z Almost-Equal-To 2, reaching the knee of the ultraviolet luminosity function of galaxies to z Almost-Equal-To 8. The survey covers approximately 800 arcmin{sup 2} and is divided into two parts. The CANDELS/Deep survey (5{sigma} point-source limit H = 27.7 mag) covers {approx}125 arcmin{sup 2} within Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S. The CANDELS/Wide survey includes GOODS and three additional fields (Extended Groth Strip, COSMOS, and Ultra-deep Survey) and covers the full area to a 5{sigma} point-source limit of H {approx}> 27.0 mag. Together with the Hubble Ultra Deep Fields, the strategy creates a three-tiered 'wedding-cake' approach that has proven efficient for extragalactic surveys. Data from the survey are nonproprietary and are useful for a wide variety of science investigations. In this paper, we describe the basic motivations for the survey, the CANDELS team science goals and the resulting observational requirements, the field selection and geometry, and the observing design. The Hubble data processing and products are described in a companion paper.

  8. The near-infrared continuum emission of visual reflection nebulae

    NASA Technical Reports Server (NTRS)

    Sellgren, K.

    1984-01-01

    In the past, reflection nebulae have provided an astrophysical laboratory well suited for the study of the reflection properties of interstellar dust grains at visual and ultraviolet wavelengths. The present investigation is concerned with observations which were begun with the objective to extend to near-infrared wavelengths the study of grains in reflection. Observations of three classical visual reflection nebulae were conducted in the wavelength range from 1.25 to 2.2 microns, taking into account NGC 7023, 2023, and 2068. All three nebulae were found to have similar near-infrared colors, despite widely different colors of their illuminating stars. The brightness level shown by two of the nebulae at 2.2 microns was too high to be easily accounted for on the basis of reflected light. Attention is given to a wide variety of possible emission mechanisms.

  9. Image-guided cancer surgery using near-infrared fluorescence

    PubMed Central

    Vahrmeijer, Alexander L.; Hutteman, Merlijn; van der Vorst, Joost R.; van de Velde, C.J.H.; Frangioni, John V.

    2013-01-01

    Paradigm shifts in surgery arise when surgeons are empowered to perform surgery faster, better, and/or less expensively. Optical imaging that exploits invisible near-infrared fluorescent light has the potential to improve cancer surgery outcomes while minimizing anesthesia time and lowering healthcare costs. Because of this, the last few years have witnessed an explosion of proof-of-concept clinical trials in the field. In this review, we introduce the concept of near-infrared fluorescence imaging for cancer surgery, review the clinical trial literature to date, outline the key issues pertaining to imaging system and contrast agent optimization, discuss limitations and leverage, and provide a framework for making the technology available for the routine care of cancer patients in the near future. PMID:23881033

  10. Near-infrared photodetector with reduced dark current

    DOEpatents

    Klem, John F; Kim, Jin K

    2012-10-30

    A photodetector is disclosed for the detection of near-infrared light with a wavelength in the range of about 0.9-1.7 microns. The photodetector, which can be formed as either an nBp device or a pBn device on an InP substrate, includes an InGaAs light-absorbing layer, an InAlGaAs graded layer, an InAlAs or InP barrier layer, and an InGaAs contact layer. The photodetector can detect near-infrared light with or without the use of an applied reverse-bias voltage and is useful as an individual photodetector, or to form a focal plane array.

  11. Noninvasive detection of gas exchange rate by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Mao, Zongzhen; Wang, Bangde

    2008-12-01

    In order to study the relationship among the oxygen concentration in skeletal muscle tissues and the heart rate (HR), oxygen uptake (VO2), respiratory exchange ratio (RER) during incremental running exercises on a treadmill, a near-infrared spectroscopy muscle oxygen monitor system is employed to measure the relative change in muscle oxygenation, with the heart rate, oxygen uptake, production of carbon dioxide (VCO2) and respiratory exchange ratio are recorded synchronously. The results indicate parameters mentioned above present regular changes during the incremental exercise. High correlations are discovered between relative change of oxy-hemoglobin concentration and heart rate, oxygen uptake, respiratory exchange ratio at the significance level (P=0.01). This research might introduce a new measurement technology and/or a novel biological monitoring parameter to the evaluation of physical function status, control the training intensity, estimation of the effectiveness of exercise. Keywords: near-infrared spectroscopy; muscle oxygen concentration; heart rate; oxygen uptake; respiratory exchange ratio.

  12. Near-infrared Mueller matrix imaging for colonic cancer detection

    NASA Astrophysics Data System (ADS)

    Wang, Jianfeng; Zheng, Wei; Lin, Kan; Huang, Zhiwei

    2016-03-01

    Mueller matrix imaging along with polar decomposition method was employed for the colonic cancer detection by polarized light in the near-infrared spectral range (700-1100 nm). A high-speed (<5s) Muller matrix imaging system with dual-rotating waveplates was developed. 16 (4 by 4) full Mueller matrices of the colonic tissues (i.e., normal and caner) were acquired. Polar decomposition was further implemented on the 16 images to derive the diattentuation, depolarization, and the retardance images. The decomposed images showed clear margin between the normal and cancerous colon tissue samples. The work shows the potential of near-infrared Mueller matrix imaging for the early diagnosis and detection of malignant lesions in the colon.

  13. Near-Infrared Quantum Cutting Long Persistent Luminescence.

    PubMed

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called "near-infrared quantum cutting long persistent luminescence (NQPL)", which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr(3+),Yb(3+). It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in (3)P0 levels of Pr(3+). Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging. PMID:27143282

  14. Near-Infrared Quantum Cutting Long Persistent Luminescence

    PubMed Central

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called “near-infrared quantum cutting long persistent luminescence (NQPL)”, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in 3P0 levels of Pr3+. Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging. PMID:27143282

  15. THE LIFETIME AND POWERS OF FR IIs IN GALAXY CLUSTERS

    SciTech Connect

    Antognini, Joe; Bird, Jonathan; Martini, Paul E-mail: bird@astronomy.ohio-state.edu

    2012-09-10

    We have identified and studied a sample of 151 FR IIs found in brightest cluster galaxies (BCGs) in the MaxBCG cluster catalog with data from FIRST and NVSS. We have compared the radio luminosities and projected lengths of these FR IIs to the projected length distribution of a range of mock catalogs generated by an FR II model and estimate the FR II lifetime to be 1.9 Multiplication-Sign 10{sup 8} yr. The uncertainty in the lifetime calculation is a factor of two, primarily due to uncertainties in the intracluster medium (ICM) density and the FR II axial ratio. We furthermore measure the jet power distribution of FR IIs in BCGs and find that it is well described by a log-normal distribution with a median power of 1.1 Multiplication-Sign 10{sup 37} W and a coefficient of variation of 2.2. These jet powers are nearly linearly related to the observed luminosities, and this relation is steeper than many other estimates, although it is dependent on the jet model. We investigate correlations between FR II and cluster properties and find that galaxy luminosity is correlated with jet power. This implies that jet power is also correlated with black hole mass, as the stellar luminosity of a BCG should be a good proxy for its spheroid mass and therefore the black hole mass. Jet power, however, is not correlated with cluster richness, nor is FR II lifetime strongly correlated with any cluster properties. We calculate the enthalpy of the lobes to examine the impact of the FR IIs on the ICM and find that heating due to adiabatic expansion is too small to offset radiative cooling by a factor of at least six. In contrast, the jet power is approximately an order of magnitude larger than required to counteract cooling. We conclude that if feedback from FR IIs offsets cooling of the ICM, then heating must be primarily due to another mechanism associated with FR II expansion.

  16. Near-infrared emission from mesoporous crystalline germanium

    NASA Astrophysics Data System (ADS)

    Boucherif, Abderraouf; Korinek, Andreas; Aimez, Vincent; Arès, Richard

    2014-10-01

    Mesoporous crystalline germanium was fabricated by bipolar electrochemical etching of Ge wafer in HF-based electrolyte. It yields uniform mesoporous germanium layers composed of high density of crystallites with an average size 5-7 nm. Subsequent extended chemical etching allows tuning of crystallites size while preserving the same chemical composition. This highly controllable nanostructure exhibits photoluminescence emission above the bulk Ge bandgap, in the near-infrared range (1095-1360nm) with strong evidence of quantum confinement within the crystallites.

  17. Near-infrared emission from mesoporous crystalline germanium

    SciTech Connect

    Boucherif, Abderraouf; Aimez, Vincent; Arès, Richard; Korinek, Andreas

    2014-10-15

    Mesoporous crystalline germanium was fabricated by bipolar electrochemical etching of Ge wafer in HF-based electrolyte. It yields uniform mesoporous germanium layers composed of high density of crystallites with an average size 5-7 nm. Subsequent extended chemical etching allows tuning of crystallites size while preserving the same chemical composition. This highly controllable nanostructure exhibits photoluminescence emission above the bulk Ge bandgap, in the near-infrared range (1095-1360nm) with strong evidence of quantum confinement within the crystallites.

  18. Near-infrared spark source excitation for fluorescence lifetime measurements

    NASA Astrophysics Data System (ADS)

    Birch, D. J. S.; Hungerford, G.; Imhof, R. E.

    1991-10-01

    We have extended the range of excitation wavelengths from spark sources used in single photon timing fluorometry into the near infrared by means of the all-metal coaxial flashlamp filled with an argon-hydrogen gas mixture. At 750 nm this mixture gives ˜15 times the intensity available from pure hydrogen for a comparable pulse duration. Measurements are demonstrated by using the laser dye IR-140 in acetone, for which a fluorescence lifetime of 1.20 ns is recorded.

  19. [Near infrared spectroscopy study on water content in turbine oil].

    PubMed

    Chen, Bin; Liu, Ge; Zhang, Xian-Ming

    2013-11-01

    Near infrared (NIR) spectroscopy combined with successive projections algorithm (SPA) was investigated for determination of water content in turbine oil. Through the 57 samples of different water content in turbine oil scanned applying near infrared (NIR) spectroscopy, with the water content in the turbine oil of 0-0.156%, different pretreatment methods such as the original spectra, first derivative spectra and differential polynomial least squares fitting algorithm Savitzky-Golay (SG), and successive projections algorithm (SPA) were applied for the extraction of effective wavelengths, the correlation coefficient (R) and root mean square error (RMSE) were used as the model evaluation indices, accordingly water content in turbine oil was investigated. The results indicated that the original spectra with different water content in turbine oil were pretreated by the performance of first derivative + SG pretreatments, then the selected effective wavelengths were used as the inputs of least square support vector machine (LS-SVM). A total of 16 variables selected by SPA were employed to construct the model of SPA and least square support vector machine (SPA-LS-SVM). There is 9 as The correlation coefficient was 0.975 9 and the root of mean square error of validation set was 2.655 8 x 10(-3) using the model, and it is feasible to determine the water content in oil using near infrared spectroscopy and SPA-LS-SVM, and an excellent prediction precision was obtained. This study supplied a new and alternative approach to the further application of near infrared spectroscopy in on-line monitoring of contamination such as water content in oil.

  20. Practice of near-infrared photography of snowpits

    NASA Astrophysics Data System (ADS)

    Schneebeli, M.

    2008-12-01

    Documentation and quantification of snow pits using near-infrared sensitive photography is a cheap and efficient technique (Matzl and Schneebeli, 2006). However, the quantitative processing of images from conventional digital cameras is not without pitfalls. The camera must be calibrated for intensity variation caused by the optic, which must done under homogenous illumination. In the field, a simple way was found to setup diffuse illumination, to prepare the pit, to position the calibration targets and to take the flat field reference image. The processing of the raw image to determine the absolute reflectivity requires several steps. First, the green channel of the raw image is extracted and interpolated. The green channel of most digital CCD has the highest number of pixels. Because the red-green-blue filters on the chip filter near- infrared red differently, a single color channel image is less noisy than a composite image. This raw image is then normalized by the optical correction image, and subsequently corrected for illumination heterogeneity by the field flat field image. This image can now be referenced to absolute reflectivity using the calibration targets. The calibrated image is used to segment quantitatively for optical grain diameter and specific surface area. A more qualitative interpretation of the snow stratigraphy, using image classification algorithms, is also possible. The equipment developed for near-infrared photography is transportable in a backpack and is used in alpine terrain. Images from different field campaigns in the Alps show the wide range of features, which are not easily documented using traditional stratigraphy. Matzl, M.; Schneebeli, M., 2006: Measuring specific surface area of snow by near-infrared photography. J. Glaciol. 52, 179: 558-564

  1. Near-infrared sensitive organic-inorganic photorefractive device

    NASA Astrophysics Data System (ADS)

    Marinova, Vera; Liu, Ren-Chung; Lin, Shiuan-Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken-Yuh

    2016-07-01

    Organic-inorganic hybrid structure, assembled by Rh-doped Bi12TiO20 crystal and liquid crystal (LC) layer, operating at near-infrared range is proposed and demonstrated. Due to the photorefractive properties of inorganic substrate, light illumination caused a space charge field which acts as a driving force for LC molecules re-alignment and subsequent refractive index modulation. All optically controlled phase retardation ability has been demonstrated supporting possibilities for further infrared applications.

  2. Near-infrared light activated azo-BF2 switches.

    PubMed

    Yang, Yin; Hughes, Russell P; Aprahamian, Ivan

    2014-09-24

    Increasing the electron density in BF2-coodinated azo compounds through para-substitution leads to a bathochromic shift in their activation wavelength. When the substituent is dimethyl amine, or the like, the trans/cis isomerization process can be efficiently modulated using near infrared light. The electron donating capability of the substituent also controls the hydrolysis half-life of the switch in aqueous solution, which is drastically longer for the cis isomer, while the BF2-coodination prevents reduction by glutathione.

  3. Near-infrared sensitive organic-inorganic photorefractive device

    NASA Astrophysics Data System (ADS)

    Marinova, Vera; Liu, Ren-Chung; Lin, Shiuan-Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken-Yuh

    2016-10-01

    Organic-inorganic hybrid structure, assembled by Rh-doped Bi12TiO20 crystal and liquid crystal (LC) layer, operating at near-infrared range is proposed and demonstrated. Due to the photorefractive properties of inorganic substrate, light illumination caused a space charge field which acts as a driving force for LC molecules re-alignment and subsequent refractive index modulation. All optically controlled phase retardation ability has been demonstrated supporting possibilities for further infrared applications.

  4. A near-infrared SETI experiment: instrument overview

    NASA Astrophysics Data System (ADS)

    Wright, Shelley A.; Werthimer, Dan; Treffers, Richard R.; Maire, Jérôme; Marcy, Geoffrey W.; Stone, Remington P. S.; Drake, Frank; Meyer, Elliot; Dorval, Patrick; Siemion, Andrew

    2014-07-01

    We are designing and constructing a new SETI (Search for Extraterrestrial Intelligence) instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared wavelengths. The new instrument design builds upon our past optical SETI experiences, and is the first step toward a new, more versatile and sophisticated generation of very fast optical and near-infrared pulse search devices. We present our instrumental design by giving an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. This project makes use of near-infrared (950 - 1650 nm) discrete amplification Avalanche Photodiodes (APD) that have > 1 GHz bandwidths with low noise characteristics and moderate gain (~104). We have investigated the use of single versus multiple detectors in our instrument (see Maire et al., this conference), and have optimized the system to have both high sensitivity and low false coincidence rates. Our design is optimized for use behind a 1m telescope and includes an optical camera for acquisition and guiding. A goal is to make our instrument relatively economical and easy to duplicate. We describe our observational setup and our initial search strategies for SETI targets, and for potential interesting compact astrophysical objects.

  5. High Efficiency Near Infrared Spectrometer for Zodiacal Light Spectral Study

    NASA Technical Reports Server (NTRS)

    Kutyrea, A. S.

    2008-01-01

    We are developing a near infrared spectrometer for measuring solar absorption lines in the zodiacal light in the near infrared region. R. Reynolds at el. (2004, ApJ 61 2, 1206) demonstrated that observing single Fraunhofer line can be a powerful tool for extracting zodiacal light parameters based on their measurements of the profile of the Mg I lneat 5 184 A. We are extending this technique to the near infrared with the primary goal of measuring the absolute intensity of the zodiacal light. This measurement will provide the crucial information needed to accurately subtract zodiacal emission from the DIRBE measurements to get a much higher quality measurement of the extragalactic IR background. The instrument design is based on a dual Fabry-Perot interferometer with a narrow band filter. Its double etalon design allows to achieve high spectral contrast to reject the bright out of band telluric OH emission. High spectral contrast is absolutely necessary to achieve detection limits needed to accurately measure the intensity of the absorption line. We present the design, estimated performance of the instrument with the expected results of the observing program.

  6. IR CMOS: near infrared enhanced digital imaging (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Pralle, Martin U.; Carey, James E.; Joy, Thomas; Vineis, Chris J.; Palsule, Chintamani

    2015-08-01

    SiOnyx has demonstrated imaging at light levels below 1 mLux (moonless starlight) at video frame rates with a 720P CMOS image sensor in a compact, low latency camera. Low light imaging is enabled by the combination of enhanced quantum efficiency in the near infrared together with state of the art low noise image sensor design. The quantum efficiency enhancements are achieved by applying Black Silicon, SiOnyx's proprietary ultrafast laser semiconductor processing technology. In the near infrared, silicon's native indirect bandgap results in low absorption coefficients and long absorption lengths. The Black Silicon nanostructured layer fundamentally disrupts this paradigm by enhancing the absorption of light within a thin pixel layer making 5 microns of silicon equivalent to over 300 microns of standard silicon. This results in a demonstrate 10 fold improvements in near infrared sensitivity over incumbent imaging technology while maintaining complete compatibility with standard CMOS image sensor process flows. Applications include surveillance, nightvision, and 1064nm laser see spot. Imaging performance metrics will be discussed. Demonstrated performance characteristics: Pixel size : 5.6 and 10 um Array size: 720P/1.3Mpix Frame rate: 60 Hz Read noise: 2 ele/pixel Spectral sensitivity: 400 to 1200 nm (with 10x QE at 1064nm) Daytime imaging: color (Bayer pattern) Nighttime imaging: moonless starlight conditions 1064nm laser imaging: daytime imaging out to 2Km

  7. Near-infrared imaging spectrometer onboard NEXTSat-1

    NASA Astrophysics Data System (ADS)

    Jeong, Woong-Seob; Park, Sung-Joon; Moon, Bongkon; Lee, Dae-Hee; Pyo, Jeonghyun; Park, Won-Kee; Park, Youngsik; Kim, Il-Joong; Ko, Kyeongyeon; Lee, Dukhang; Kim, Min Gyu; Kim, Minjin; Ko, Jongwan; Shin, Goo-Hwan; Chae, Jangsoo; Matsumoto, Toshio

    2016-07-01

    The NISS (Near-infrared Imaging Spectrometer for Star formation history) is the near-infrared instrument optimized to the first next generation of small satellite (NEXTSat-1) in Korea. The spectro-photometric capability in the near-infrared range is a unique function of the NISS. The major scientific mission is to study the cosmic star formation history in local and distant universe. For those purposes, the NISS will perform the large areal imaging spectroscopic survey for astronomical objects and low background regions. We have paid careful attention to reduce the volume and to increase the total throughput. The newly implemented off-axis optics has a wide field of view (2° x 2°) and a wide wavelength range from 0.9 to 3.8μm. The mechanical structure is designed to consider launching conditions and passive cooling of the telescope. The compact dewar after relay-lens module is to operate the infrared detector and spectral filters at 80K stage. The independent integration of relay-lens part and primary-secondary mirror assembly alleviates the complex alignment process. We confirmed that the telescope and the infrared sensor can be cooled down to around 200K and 80K, respectively. The engineering qualification model of the NISS was tested in the space environment including the launch-induced vibration and shock. The NISS will be expected to demonstrate core technologies related to the development of the future infrared space telescope in Korea.

  8. Optical motion detector detecting visible and near infrared light

    NASA Astrophysics Data System (ADS)

    Everett, Hobart R., Jr.

    1990-02-01

    An optical motion detector detects changes in scene lighting indicative of motion and is also capable of detecting surveillance by active night vision devices using near-infrared light. The detector includes two photodetectors which each provide data to a signal processing network. One photodetector is sensitive to visible light; the other to near-infrared light. Both signal processing networks are identical and include a sample-and-hold, a comparator network, and a pulse stretcher. The output of a photodetector is provided to the sample-and-hold and comparator network. The comparator network compares a voltage corresponding to the instantaneously detected ambient lighting scene with a voltage corresponding to a reference lighting scene. The pulse stretcher receives the output of the comparator network and in turn provides an output to a logical processor. The logical processor compares the outputs of both signal processing networks and provides an output indicating surveillance with near-infrared light. The logical processor also indicates any perturbations in intensities of incandescent and fluorescent light.

  9. Near-Infrared Fluorescent Materials for Sensing of Biological Targets

    PubMed Central

    Amiot, Carrie L.; Xu, Shuping; Liang, Song; Pan, Lingyun; Zhao, Julia Xiaojun

    2008-01-01

    Near-infrared fluorescent (NIRF) materials are promising labeling reagents for sensitive determination and imaging of biological targets. In the near-infrared region biological samples have low background fluorescence signals, providing high signal to noise ratio. Meanwhile, near-infrared radiation can penetrate into sample matrices deeply due to low light scattering. Thus, in vivo and in vitro imaging of biological samples can be achieved by employing the NIRF probes. To take full advantage of NIRF materials in the biological and biomedical field, one of the key issues is to develop intense and biocompatible NIRF probes. In this review, a number of NIRF materials are discussed including traditional NIRF dye molecules, newly developed NIRF quantum dots and single-walled carbon nanotubes, as well as rare earth metal compounds. The use of some NIRF materials in various nanostructures is illustrated. The enhancement of NIRF using metal nanostructures is covered as well. The fluorescence mechanism and bioapplications of each type of the NIRF materials are discussed in details.

  10. Tunable Near-Infrared Luminescence in Tin Halide Perovskite Devices.

    PubMed

    Lai, May L; Tay, Timothy Y S; Sadhanala, Aditya; Dutton, Siân E; Li, Guangru; Friend, Richard H; Tan, Zhi-Kuang

    2016-07-21

    Infrared emitters are reasonably rare in solution-processed materials. Recently, research into hybrid organo-lead halide perovskite, originally popular in photovoltaics,1-3 has gained traction in light-emitting diodes (LED) due to their low-cost solution processing and good performance.4-9 The lead-based electroluminescent materials show strong colorful emission in the visible region, but lack emissive variants further in the infrared. The concerns with the toxicity of lead may, additionally, limit their wide-scale applications. Here, we demonstrate tunable near-infrared electroluminescence from a lead-free organo-tin halide perovskite, using an ITO/PEDOT:PSS/CH3NH3Sn(Br1-xIx)3/F8/Ca/Ag device architecture. In our tin iodide (CH3NH3SnI3) LEDs, we achieved a 945 nm near-infrared emission with a radiance of 3.4 W sr(-1) m(-2) and a maximum external quantum efficiency of 0.72%, comparable with earlier lead-based devices. Increasing the bromide content in these tin perovskite devices widens the semiconductor bandgap and leads to shorter wavelength emissions, tunable down to 667 nm. These near-infrared LEDs could find useful applications in a range of optical communication, sensing and medical device applications.

  11. Analytical approximations of K-corrections in optical and near-infrared bands

    NASA Astrophysics Data System (ADS)

    Chilingarian, Igor V.; Melchior, Anne-Laure; Zolotukhin, Ivan Yu.

    2010-07-01

    To compare photometric properties of galaxies at different redshifts, the fluxes need to be corrected for the changes of effective rest-frame wavelengths of filter bandpasses, called K-corrections. Usual approaches to compute them are based on the template fitting of observed spectral energy distributions (SED) and, thus, require multicolour photometry. Here, we demonstrate that, in cases of widely used optical and near-infrared (NIR) filters, K-corrections can be precisely approximated as two-dimensional low-order polynomials of only two parameters: redshift and one observed colour. With this minimalist approach, we present the polynomial fitting functions for K-corrections in Sloan Digital Sky Survey (SDSS) ugriz, United Kingdom Infrared Telescope (UKIRT) Wide Field Camera YJHK, Johnson-Cousins UBVRcIc and Two Micron All Sky Survey JHKs bands for galaxies at redshifts Z < 0.5 based on empirically computed values obtained by fitting combined optical-NIR SEDs of a set of 105 galaxies constructed from SDSS Data Release 7 (DR7) and UKIRT Infrared Deep Sky Survey DR5 photometry using the Virtual Observatory. For luminous red galaxies we provide K-corrections as functions of their redshifts only. In two filters, g and r, we validate our solutions by computing K-corrections directly from SDSS DR7 spectra. We also present a K-corrections calculator, a web-based service for computing K-corrections online.

  12. Large Magellanic Cloud Near-Infrared Synoptic Survey - III. A statistical study of non-linearity in the Leavitt Laws

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Anupam; Kanbur, Shashi M.; Macri, Lucas M.; Singh, Harinder P.; Ngeow, Chow-Choong; Ishida, Emille E. O.

    2016-04-01

    We present a detailed statistical analysis of possible non-linearities in the period-luminosity (PL), period-Wesenheit (PW) and period-colour (PC) relations for Cepheid variables in the Large Magellanic Cloud (LMC) at optical (VI) and near-infrared (JHKs) wavelengths. We test for the presence of possible non-linearities and determine their statistical significance by applying a variety of robust statistical tests (F-test, random-walk, testimator and the Davies test) to optical data from third phase of the Optical Gravitational Lensing Experiment and near-infrared data from Large Magellanic Cloud Near-Infrared Synoptic Survey. For fundamental-mode Cepheids, we find that the optical PL, PW and PC relations are non-linear at 10 d. The near-infrared PL and the W^H_{V,I} relations are non-linear around 18 d; this break is attributed to a distinct variation in mean Fourier amplitude parameters near this period for longer wavelengths as compared to optical bands. The near-infrared PW relations are also non-linear except for the W_{H,K_s} relation. For first-overtone mode Cepheids, a significant change in the slope of PL, PW and PC relations is found around 2.5 d only at optical wavelengths. We determine a global slope of -3.212 ± 0.013 for the W^H_{V,I} relation by combining our LMC data with observations of Cepheids in Supernovae host galaxies. We find this slope to be consistent with the corresponding LMC relation at short periods, and significantly different to the long-period value. We do not find any significant difference in the slope of the global-fit solution using a linear or non-linear LMC PL relation as calibrator, but the linear version provides a two times better constraint on the slope and metallicity coefficient.

  13. Near-infrared images of the nuclear region of NGC 5128

    NASA Technical Reports Server (NTRS)

    Turner, Paula C.; Forrest, William J.; Pipher, Judith L.; Shure, Mark A.

    1992-01-01

    High-resolution near-infrared images of NGC 5128 (Centaurus A) are presented, which probe the optically obscured nuclear region. The images show a central source at K (2.23 microns) and 3.26 microns. This central object is not prominent in the shorter wavelength images at J and H (1.23 and 1.65 micron, respectively), probably due to high extinction. The color images (H - K and J - H) provide evidence for a steep gradient in extinction across the array field. The images indicate three components: a red, variable, compact nucleus; the diffuse elliptical galaxy starlight; and a blue extension to the NE. The nucleus has decreased in flux density by a factor of 2.5 over less than about 5 yr at 3.26 microns. However, current spectral constraints on the nuclear source at near-infrared wavelengths cannot definitively determine the relative contributions from the known ratio synchrotron source (AGN) and from various possible dust-enshrouded thermal sources. The blue spot, approximately 7.6 +/- 0.1 arcsec NE of the nucleus appears to be a hole in the extinction, possibly enhanced by scattered light from the active galactic nucleus.

  14. Integral field spectroscopy of a sample of nearby galaxies. II. Properties of the H ii regions

    NASA Astrophysics Data System (ADS)

    Sánchez, S. F.; Rosales-Ortega, F. F.; Marino, R. A.; Iglesias-Páramo, J.; Vílchez, J. M.; Kennicutt, R. C.; Díaz, A. I.; Mast, D.; Monreal-Ibero, A.; García-Benito, R.; Bland-Hawthorn, J.; Pérez, E.; González Delgado, R.; Husemann, B.; López-Sánchez, Á. R.; Cid Fernandes, R.; Kehrig, C.; Walcher, C. J.; Gil de Paz, A.; Ellis, S.

    2012-10-01

    We analyse the spectroscopic properties of thousands of H ii regions identified in 38 face-on spiral galaxies. All galaxies were observed out to 2.4 effective radii using integral field spectroscopy (IFS) over the wavelength range ~3700 to ~6900 Å. The near uniform sample has been assembled from the PPAK IFS Nearby Galaxy (PINGS) survey and a sample described in Paper I. We develop a new automatic procedure to detect H ii regions, based on the contrast of the Hα intensity maps extracted from the datacubes. Once detected, the algorithm provides us with the integrated spectra of each individual segmented region. In total, we derive good quality spectroscopic information for ~2600 independent H ii regions/complexes. This is by far the largest H ii region survey of its kind. Our selection criteria and the use of 3D spectroscopy guarantee that we cover the regions in an unbiased way. A well-tested automatic decoupling procedure has been applied to remove the underlying stellar population, deriving the main properties (intensity, dispersion and velocity) of the strongest emission lines in the considered wavelength range (covering from [O ii] λ3727 to [S ii] λ6731). A final catalogue of the spectroscopic properties of H ii regions has been created for each galaxy, which includes information on morphology, spiral structure, gaskinematics, and surface brightness of the underlying stellar population. In the current study, we focus on the understanding of the average properties of the H ii regions and their radial distributions. We find a significant change in the ionisation characteristics of H ii regions within r < 0.25 re due to contamination from sources with different ionising characteristics, as we discuss. We find that the gas-phase oxygen abundance and the Hα equivalent width present a negative and positive gradient, respectively. The distribution of slopes is statistically compatible with a random Gaussian distribution around the mean value, if the radial

  15. Near-infrared Characterization of the Atmospheres of Alien Worlds

    NASA Astrophysics Data System (ADS)

    Croll, Bryce

    In this thesis I present near-infrared detections of the thermal emission of a number of hot Jupiters and likely transit depth differences from different wavelength observations of a super-Earth. I have pioneered "Staring Mode" using the Wide-field Infrared Camera on the Canada-France-Hawaii Telescope to achieve the most accurate photometry to-date in the near- infrared from the ground. I also discuss avenues that should allow one to achieve even more accurate photometry in the future. Using WIRCam on CFHT my collaborators and I have detected the thermal emission of the following hot Jupiters: TrES-2b and TrES-3b in Ks-band, WASP-12b in the J, H & Ks-bands, and WASP-3b in the Ks-band on two occasions. Near- infrared detections of the thermal emission of hot Jupiters are important, because the majority of these planets' blackbodies peak in this wavelength range; near-infrared detections allow us to obtain the most model-independent constraints on these planets' atmospheric characteristics, their temperature-pressure profiles with depth and an estimate of their bolometric luminosities. With these detections we are able to answer such questions as: how efficiently these planets redistribute heat to their nightsides, if they're being inflated by tidal heating, whether there's any evidence that one of these planets is precessing, and whether another experiences extreme weather and violent storms? My collaborators and I have also observed several transits of the super-Earth GJ 1214b. We find a deeper transit depth in one of our near-infrared bands than the other. This is likely indicative of a spectral absorption feature. For the differences in the transit depth to be as large as we observed, the atmosphere of GJ 1214b must have a large scale height, low mean molecular weight and thus have a hydrogen/helium dominated atmosphere. Given that other researchers have not found similar transit depth differences, we also discuss the most likely atmospheric makeup for this

  16. Star formation thresholds in H II galaxies with H I companions

    NASA Technical Reports Server (NTRS)

    Taylor, Christopher L.; Brinks, Elias; Pogge, Richard W.; Skillman, Evan D.

    1994-01-01

    We present high resolution Very Large Array (VLA) 21 cm line observations of five H II galaxies combined with previous lower resolution data from Taylor et al. (1993) and optical broadband R and H-alpha Charge Coupled Device (CCD) images of the systems. Following Kennicutt (1989) we calculated the threshold H I surface density for star formation for the H II galaxies and compared the location and shape of this predicted threshold density contour with the optical shape of the galaxies. We find generally a good correlation between these two, although a constant density contour of 10(exp 21)/sq cm fits the images of the optical galaxies equally as well. The H I synthesis observations have revealed that the H II galaxies have sharply peaked H I radial profiles, in contrast to the relatively flattened profiles of low surface brightness (LSB) galaxies, suggesting that large central concentrations of gas are a necessary condition for the occurrence of bursts of massive star formation seen in H II galaxies. These observations are consistent with the hypothesis that LSB galaxies represent the quiescent phase of H II galaxies, if a suitable mechanism exists (such as galaxy interactions) to cause H I to concentrate at the center of LSB galaxies prior to the onset of the burst of star formation. However, it is noted that the H II galaxies (and dwarf galaxies in general) span a relatively large range in mass. Since many properties correlate with mass (e.g., gas mass fraction), we point out that great care needs to be taken in choosing the proper comparison samples of LSB and H II galaxies.

  17. Reanalysis of the Near-infrared Extragalactic Background Light Based on the IRTS Observations

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  18. NEAR-INFRARED (JHK) PHOTOMETRY OF 131 NORTHERN GALACTIC CLASSICAL CEPHEIDS

    SciTech Connect

    Monson, Andrew J.; Pierce, Michael J.

    2011-03-15

    Near-infrared photometric measurements for 131 Northern Galactic Cepheids are presented. The Cepheid light curves are sampled with an average of 22 measurements per star fully covering the phase of each Cepheid. The J, H, and K light curves for each Cepheid were uniformly interpolated to find the intensity mean magnitudes within each band. The results are consistent within {+-}1% for 26 stars in common with previous studies. This paper is the first in a projected series of two papers which will provide additional fundamental data for Cepheids in the Galaxy, namely, NIR photometry and line-of-sight extinction. In the course of this project, 93 additional variables were fortuitously observed within the Cepheid program fields, 82 of which have previously not been identified.

  19. REANALYSIS OF THE NEAR-INFRARED EXTRAGALACTIC BACKGROUND LIGHT BASED ON THE IRTS OBSERVATIONS

    SciTech Connect

    Matsumoto, T.; Kim, M. G.; Pyo, J.; Tsumura, K.

    2015-07-01

    We reanalyze data of the near-infrared background taken by IRTS using up-to-date observational results of zodiacal light (ZL), integrated star light, and diffuse Galactic light. We confirm the existence of residual isotropic emission, which is slightly lower but almost the same as previously reported. At wavelengths longer than 2 μm, the result is fairly consistent with the recent observation with AKARI. We also perform the same analysis using a different ZL model by Wright and detect residual isotropic emission that is slightly lower than that based on the original Kelsall model. Both models show residual isotropic emission that is significantly brighter than the integrated light of galaxies.

  20. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  1. The James Webb Space Telescope's Near-Infrared Camera (NIRCam): Making Models, Building Understanding

    NASA Astrophysics Data System (ADS)

    McCarthy, D. W., Jr.; Lebofsky, L. A.; Higgins, M. L.; Lebofsky, N. R.

    2011-09-01

    Since 2003, the Near Infrared Camear (NIRCam) science team for the James Webb Space Telescope (JWST) has conducted "Train the Trainer" workshops for adult leaders of the Girl Scout of the USA (GSUSA), engaging them in the process of scientific inquiry and equipping them to host astronomy-related activities at the troop level. Training includes topics in basic astronomy (night sky, phases of the Moon, the scale of the Solar System and beyond, stars, galaxies, telescopes, etc.) as well as JWST-specific research areas in extra-solar planetary systems and cosmology, to pave the way for girls and women to understand the first images from JWST. Participants become part of our world-wide network of 160 trainers teaching young women essential STEM-related concepts using astronomy, the night sky environment, applied math, engineering, and critical thinking.

  2. [C II] and [N II] from dense ionized regions in the Galaxy

    NASA Astrophysics Data System (ADS)

    Langer, W. D.; Goldsmith, P. F.; Pineda, J. L.

    2016-05-01

    Context. The interstellar medium (ISM) consists of highly ionized and neutral atomic, as well as molecular, components. Knowledge of their distribution is important for tracing the structure and lifecycle of the ISM. Aims: To determine the properties of the highly ionized gas and neutral weakly ionized gas in the Galaxy traced by the fine-structure lines of ionized nitrogen, [N ii], and ionized carbon, [C ii]. Methods: We utilize observations of the [C ii] 158 μm and [N ii] 205 μm fine-structure lines taken with the high spectral resolution Heterodyne Instrument in the Far-Infrared (HIFI) on the Herschel Space Observatory along ten lines of sight towards the inner Galaxy to analyze the ionized ISM. The [N ii] emission can be used to estimate the contribution of the highly ionized gas to the [C ii] emission and separate the contributions from highly ionized and weakly ionized neutral gas. Results: We find that [N ii] has strong emission in distinct spectral features along all lines of sight associated with strong [C ii] emission. The [N ii] arises from moderate density extended H ii regions or ionized boundary layers of clouds. Comparison of the [N ii] and [C ii] spectra in 31 separate kinematic features shows that many of the [C ii] spectra are affected by absorption from low excitation gas associated with molecular clouds, sometimes strongly so. The apparent fraction of the [C ii] associated with the [N ii] gas is unrealistically large in many cases, most likely due to the reduction of [C ii] by absorption. In a few cases the foreground absorption can be modeled to determine the true source intensity. In these sources we find that the foreground absorbing gas layer has C+ column densities of order 1018 cm-2. Conclusions: [C ii] emission arising from strong sources of [N ii] emission is frequently absorbed by low excitation foreground gas complicating the interpretation of the properties of the ionized and neutral gas components that give rise to [C ii] emission.

  3. Discovering and characterizing embedded stellar clusters in the near-infrared

    NASA Astrophysics Data System (ADS)

    Leistra, Andrea Lynn

    I present a near-infrared search for new embedded stellar clusters in the Galaxy, and the results of near-infrared followup observations of a subset of newly discovered stellar clusters. I discuss the initial mass function of these embedded clusters and the implications of the apparent method-dependent systematic error in the IMF. First, I present near-infrared J, H, and K images of six embedded stellar clusters in the Galaxy, and K-band spectroscopy for two. I find a significant fraction of pre-main-sequence stars present in at least two of the clusters. For the clusters dominated by main-sequence stars, we determine the initial mass function (IMF) both by using the K luminosity function and a global extinction correction and by deriving individual extinction corrections for each star based on their placement in the K vs. H - K color-magnitude diagram. Based on our IMFs we find a significant discrepancy between the mean IMF derived via the different methods, suggesting that taking individual extinctions into account is necessary to correctly derive the IMF for an embedded cluster. I find that using the KLF alone to derive an IMF is likely to produce an overly steep slope in stellar clusters subject to variable extinction, and examine literature results to see if the same effect exists in the work of other authors. I conduct a two-phase search of the 2MASS Point Source Catalog to discover previously unknown embedded stellar clusters and construct a more complete sample than has previously been available. Based on comparisons with the sample of known embedded stellar clusters we determine the completeness of the total existing sample to be ˜75% within 2 kpc. I discuss the limitations of previously employed algorithms for stellar cluster detection, and suggest possible alternatives for use in areas of high stellar background density. Finally I present a detailed look at two of the incorrectly identified embedded cluster candidates to better understand the

  4. [Detection of Adulteration in Milk Powder with Starch Near Infrared].

    PubMed

    Wang, Ning-ning; Shen, Bing-hui; Guan, Jian-jun; Zhao, Zhong-rui; Zhu, Ye-wei; Zhang, Lu-da; Yan, Yan-lu; Zheng, Yu-yan; Dong, Cheng-yu; Kang, Ding-ming

    2015-08-01

    Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together

  5. [Detection of Adulteration in Milk Powder with Starch Near Infrared].

    PubMed

    Wang, Ning-ning; Shen, Bing-hui; Guan, Jian-jun; Zhao, Zhong-rui; Zhu, Ye-wei; Zhang, Lu-da; Yan, Yan-lu; Zheng, Yu-yan; Dong, Cheng-yu; Kang, Ding-ming

    2015-08-01

    Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together

  6. Near-infrared dust and line emission from the central region of Mrk1066: constraints from Gemini NIFS

    NASA Astrophysics Data System (ADS)

    Riffel, Rogemar A.; Storchi-Bergmann, Thaisa; Nagar, Neil M.

    2010-05-01

    We present integral field spectroscopy of the inner 700 × 700pc2 of the Seyfert galaxy Mrk1066 obtained with Gemini's Near-Infrared Integral Field Spectrograph (NIFS) at a spatial resolution of ~35pc. This high spatial resolution allowed us to observe, for the first time in this galaxy, an unresolved dust concentration with mass ~1.4 × 10-2Msolar. This unresolved concentration, with emission well reproduced by a blackbody with temperature ~830K, is possibly part of the nuclear dusty torus. We compared maps of emission-line flux distributions and ratios with a 3.6cm radio-continuum image and [OIII] image in order to investigate the origin of the near-infrared emission. The emission-line fluxes are elongated in PA = 135°/315° in agreement with the [OIII] and radio images and, except for the H lines, are brighter to the north-west than to the south-east. This close association with the radio hot spot implies that at least part of the emitting gas is co-spatial with the radio outflow. The H emission is stronger to the south-east, where we find a large region of star-formation. The strong correlation between the radio emission and the highest emission-line fluxes indicates that the radio jet plays a fundamental role at these intensity levels. At lower emission-line fluxes this correlation disappears suggesting a contribution from the plane of the galaxy to the observed emission. The H2 flux is more uniformly distributed and has an excitation temperature of ~2100K. Its origin appears to be circum-nuclear gas heated by X-rays from the central active nucleus. The [FeII] emission also is consistent with X-ray heating, but its spatial correlation with the radio jet and [OIII] emission indicates additional emission due to excitation and/or abundance changes caused by shocks in the radio jet. The coronal-line emission of [CaVIII] and [SIX] is unresolved by our observations indicating a distribution within 18pc from the nucleus. The reddening map obtained via the Pa

  7. Visible/near-infrared spectra of experimentally shocked plagioclase feldspars

    USGS Publications Warehouse

    Johnson, J. R.; Horz, F.

    2003-01-01

    High shock pressures cause structural changes in plagioclase feldspars such as mechanical fracturing and disaggregation of the crystal lattice at submicron scales, the formation of diaplectic glass (maskelynite), and genuine melting. Past studies of visible/ near-infrared spectra of shocked feldspars demonstrated few spectral variations with pressure except for a decrease in the depth of the absorption feature near 1250-1300 nm and an overall decrease in reflectance. New visible/near-infrared spectra (400-2500 nm) of experimentally shocked (17-56 GPa) albite- and anorthite-rich rock powders demonstrate similar trends, including the loss of minor hydrated mineral bands near 1410, 1930, 2250, and 2350 nm. However, the most interesting new observations are increases in reflectance at intermediate pressures, followed by subsequent decreases in reflectance at higher pressures. The amount of internal scattering and overall sample reflectance is controlled by the relative proportions of micro-fractures, submicron grains, diaplectic glass, and melts formed during shock metamorphism. We interpret the observed reflectance increases at intermediate pressures to result from progressively larger proportions of submicron feldspar grains and diaplectic glass. The ensuing decreases in reflectance occur after diaplectic glass formation is complete and the proportion of genuine melt inclusions increases. The pressure regimes over which these reflectance variations occur differ between albite and anorthite, consistent with thermal infrared spectra of these samples and previous studies of shocked feldspars. These types of spectral variations associated with different peak shock pressures should be considered during interpretation and modeling of visible/near-infrared remotely sensed spectra of planetary and asteroidal surfaces.

  8. Innovative uses of near-infrared spectroscopy in food processing.

    PubMed

    Bock, J E; Connelly, R K

    2008-09-01

    Near-infrared spectroscopy (NIRS) has experienced widespread use as an analytical tool in the last 3 decades. Researchers today are exploring ways of applying NIRS that expand beyond compositional analyses into process control. Processes such as meat tenderness evaluation, curd cutting, and dough mixing have traditionally been controlled by highly skilled master craftsmen; new NIRS research applications are demonstrating that these complex processes can be monitored and controlled in situ to produce consistent, high quality end products with online NIRS technology. Additionally, researchers also now have the potential ability to develop new nondestructive spectroscopic techniques to probe the underlying molecular evolution of these products during processing.

  9. Detection of bottled liquid explosives by near infrared

    NASA Astrophysics Data System (ADS)

    Itozaki, Hide; Miyamura, Ryu; Sato-Akaba, Hideo

    2012-10-01

    Bottled liquids are limited to be brought in the airplane, because liquid explosives have been used in some terrorist attaches recently. A bottled liquid scanner is expected to be developed. Liquid scanner using near infrared technologies is being developed by us. Many spectrum of liquids have been collected and analyzed by chemometorics in order to separate safe beverage to explosive and dangerous liquids. This bottled liquid scanner had feasibility tests in some international airport in Japan and obtained good review from security people in the airport.

  10. Red and near-infrared spectral reflectance of snow

    NASA Technical Reports Server (NTRS)

    Obrien, H. W.; Munis, R. H.

    1975-01-01

    The spectral reflectance of snow in the range of 0.60 to 2.50 microns wavelengths was studied in a cold laboratory using natural snow and simulated preparations of snow. A white barium sulfate powder was used as the standard for comparison. The high reflectance (usually nearly 100%) of fresh natural snow in visible wavelengths declines rapidly at wavelengths longer than the visible, as the spectral absorption coefficients of ice increase. Aging snow becomes only somewhat less reflective than fresh snow in the visible region and usually retains a reflectance greater than 80%. In the near infrared, aging snow tends to become considerably less reflective than fresh snow.

  11. Feasibility of near-infrared markers for guiding surgical robots

    NASA Astrophysics Data System (ADS)

    Shademan, Azad; Dumont, Matthieu F.; Leonard, Simon; Krieger, Axel; Kim, Peter C. W.

    2013-09-01

    Automating surgery using robots requires robust visual tracking. The surgical environment often has poor light conditions where several organs have similar visual appearances. In addition, the field of view might be occluded by blood or tissue. In this paper, the feasibility of near-infrared (NIR) fluorescent marking and imaging for vision-based robot control is studied. The NIR region of the spectrum has several useful properties including deep tissue penetration. We study the optical properties of a clinically-approved NIR fluorescent dye, indocyanine green (ICG), with different concentrations and quantify image positioning error of ICG marker when obstructed by tissue.

  12. Note: wearable near-infrared spectroscopy imager for haired region.

    PubMed

    Kiguchi, M; Atsumori, H; Fukasaku, I; Kumagai, Y; Funane, T; Maki, A; Kasai, Y; Ninomiya, A

    2012-05-01

    A wearable optical topography system was developed that is based on near-infrared spectroscopy (NIRS) for observing brain activity noninvasively including in regions covered by hair. An avalanche photo diode, high voltage dc-dc converter, and preamplifier were placed in an electrically shielded case to be safely mounted on the head. Rubber teeth and a glass rod were prepared to clear away hair and reach the scalp. These devices realized for the first time a wearable NIRS imager for any region of the cortex. The activity in the motor cortex during finger tapping was successfully observed.

  13. JWST Near-Infrared Detectors: Latest Test Results

    NASA Technical Reports Server (NTRS)

    Smith, Erin C.; Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Chiao, Meng; Clemons, Brian L.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Greenhouse, Matthew A.; Henegar, Greg; Hill, Robert J.; Johnson, Thomas; Lavaque, Dodolfo J.; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Cheryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Schnurr, Richard; Smith, Miles; Waczynski, Augustyn

    2009-01-01

    The James Webb Space Telescope, an infrared-optimized space telescope being developed by NASA for launch in 2013, will utilize cutting-edge detector technology in its investigation of fundamental questions in astrophysics. JWST's near infrared spectrograph, NIRSpec utilizes two 2048 x 2048 HdCdTe arrays with Sidecar ASIC readout electronics developed by Teledyne to provide spectral coverage from 0.6 microns to 5 microns. We present recent test and calibration results for the NIRSpec flight arrays as well as data processing routines for noise reduction and cosmic ray rejection.

  14. Near-Infrared Fluorescence-Enhanced Optical Tomography

    PubMed Central

    2016-01-01

    Fluorescence-enhanced optical imaging using near-infrared (NIR) light developed for in vivo molecular targeting and reporting of cancer provides promising opportunities for diagnostic imaging. The current state of the art of NIR fluorescence-enhanced optical tomography is reviewed in the context of the principle of fluorescence, the different measurement schemes employed, and the mathematical tools established to tomographically reconstruct the fluorescence optical properties in various tissue domains. Finally, we discuss the recent advances in forward modeling and distributed memory parallel computation to provide robust, accurate, and fast fluorescence-enhanced optical tomography. PMID:27803924

  15. A near-infrared spectrograph for the Discovery Channel Telescope

    NASA Astrophysics Data System (ADS)

    Roe, H. G.; Dunham, E. W.; Bida, T. A.; Hall, J. C.; Degroff, W.

    2011-10-01

    Lowell Observatory is constructing the Discovery Channel Telescope (DCT) at Happy Jack, Arizona, approximately an hour from Lowell's main campus in Flagstaff, Arizona. The DCT is a 4.3-m optical/ infrared telescope. Construction of the telescope is complete and First Light of the DCT is planned for 2012Q2. In its initial configuration instruments will be co-mounted on a rotatable/selectable cube at the Cassegrain focus. Motorized deployable fold mirrors enable rapid switching amongst instruments. In the future the Nasmyth foci will be available for larger instruments as well. The first generation of instruments on DCT include: the Large Monolithic Imager (LMI), the Near-Infrared High-Throughput Spectrograph (NIHTS, pronounced "nights"), and the DeVeny optical spectrograph. The LMI contains a single large 6.1x6.1 K detector with a 12.5 arcmin2 FOV. NIHTS is a low resolution efficient near-infrared spectrograph and is the subject of this presentation. The DeVeny is Lowell's existing optical spectrograph with resolutions available between 500 and 4000. NIHTS is a low-resolution high-throughput infrared spectrograph covering 0.9-2.4 μm in a single fixed spectral setting at a resolution of »100. For simplicity and replicability NIHTS contains no moving parts. The science detector is a 10242 HAWAII-1 array. The fixed slit plate features an 80" long slit with several different slit widths (2,3,4 and 12 pixels) available along its length. The widest slit width is designed to allow accurate flux calibration, while the 3 and 4-pixel slits are closely matched to typical seeing at the DCT site (0.86" mean). Different resolutions will be rapidly selectable by dithering the telescope, and a typical observation is anticipated to involve a sequence of dithers both at the desired resolution and at SED resolution for calibration purposes. Offset guiding and wavefront sensing to control the active optics of the primary mirror are provided by the facility via deployable probes in

  16. Note: Wearable near-infrared spectroscopy imager for haired region

    NASA Astrophysics Data System (ADS)

    Kiguchi, M.; Atsumori, H.; Fukasaku, I.; Kumagai, Y.; Funane, T.; Maki, A.; Kasai, Y.; Ninomiya, A.

    2012-05-01

    A wearable optical topography system was developed that is based on near-infrared spectroscopy (NIRS) for observing brain activity noninvasively including in regions covered by hair. An avalanche photo diode, high voltage dc-dc converter, and preamplifier were placed in an electrically shielded case to be safely mounted on the head. Rubber teeth and a glass rod were prepared to clear away hair and reach the scalp. These devices realized for the first time a wearable NIRS imager for any region of the cortex. The activity in the motor cortex during finger tapping was successfully observed.

  17. Ultraviolet-visible-near infrared spectra of 50 samples

    SciTech Connect

    Taylor, B.

    1988-08-30

    Under the subject contract, Unidynamics/Phoenix recorded the ultraviolet-visible-near infrared spectra of 50 samples supplied by LANL. A Varian Cary 2300 series spectrophotometer produced the spectral data. The spectrophotometer was interfaced to a Varian D5-15 Data Station, and hard copies of data were made. Baseline corrections throughout the wavelength range were established using Halon as a reference material. Corrected measurements were automatically made by the system on every sample. Two types of sample holders were tried. Before collecting data on the LANL samples, identical samples of PETN were examined using both holders.

  18. Diffuse reflectance near infrared-chemometric methods development and validation of amoxicillin capsule formulations

    PubMed Central

    Khan, Ahmed Nawaz; Khar, Roop Krishen; Ajayakumar, P. V.

    2016-01-01

    Objective: The aim of present study was to establish near infrared-chemometric methods that could be effectively used for quality profiling through identification and quantification of amoxicillin (AMOX) in formulated capsule which were similar to commercial products. In order to evaluate a large number of market products easily and quickly, these methods were modeled. Materials and Methods: Thermo Scientific Antaris II near infrared analyzer with TQ Analyst Chemometric Software were used for the development and validation of the identification and quantification models. Several AMOX formulations were composed with four excipients microcrystalline cellulose, magnesium stearate, croscarmellose sodium and colloidal silicon dioxide. Development includes quadratic mixture formulation design, near infrared spectrum acquisition, spectral pretreatment and outlier detection. According to prescribed guidelines by International Conference on Harmonization (ICH) and European Medicine Agency (EMA) developed methods were validated in terms of specificity, accuracy, precision, linearity, and robustness. Results: On diffuse reflectance mode, an identification model based on discriminant analysis was successfully processed with 76 formulations; and same samples were also used for quantitative analysis using partial least square algorithm with four latent variables and 0.9937 correlation of coefficient followed by 2.17% root mean square error of calibration (RMSEC), 2.38% root mean square error of prediction (RMSEP), 2.43% root mean square error of cross-validation (RMSECV). Conclusion: Proposed model established a good relationship between the spectral information and AMOX identity as well as content. Resulted values show the performance of the proposed models which offers alternate choice for AMOX capsule evaluation, relative to that of well-established high-performance liquid chromatography method. Ultimately three commercial products were successfully evaluated using developed

  19. PMAS optical integral field spectroscopy of luminous infrared galaxies. II. Spatially resolved stellar populations and excitation conditions

    NASA Astrophysics Data System (ADS)

    Alonso-Herrero, A.; García-Marín, M.; Rodríguez Zaurín, J.; Monreal-Ibero, A.; Colina, L.; Arribas, S.

    2010-11-01

    Context. The general properties (e.g., activity class, star formation rates, metallicities, extinctions, average ages, etc.) of luminous (LIRGs) and ultraluminous infrared galaxies (ULIRGs) in the local universe are well known because large samples of these objects have been the subject of numerous spectroscopic works over the past three decades. There are, however, relatively few studies of the spatially-resolved spectroscopic properties of large samples of LIRGs and ULIRGs using integral field spectroscopy (IFS). Aims: We are carrying out an IFS survey of local (z<0.26) samples of LIRGs and ULIRGs to characterize their two-dimensional spectroscopic properties. The main goal of this paper is to study the spatially resolved properties of the stellar populations and the excitation conditions in a sample of LIRGs. Methods: We analyze optical (3800-7200 Å) IFS data taken with the Potsdam Multi-Aperture Spectrophotometer (PMAS) of the central few kiloparsecs of eleven LIRGs. To study these stellar populations, we fit the optical stellar continuum and the hydrogen recombination lines of selected regions in the galaxies. We analyzed the excitation conditions of the gas using the spatially resolved properties of the brightest optical emission lines. We complemented the PMAS observations with existing HST/NICMOS near-infrared continuum and Paα imaging. Results: The optical continua of selected regions in our LIRGs are well fitted with a combination of an evolved (~0.7-10 Gyr) stellar population with an ionizing stellar population (1-20 Myr). The latter population is more obscured than the evolved population, and has visual extinctions in good agreement with those obtained from the Balmer decrement. Except for NGC 7771, we find no clear that there is an important contribution to the optical light from an intermediate-aged stellar population (~100-500 Myr). Even after correcting for the presence of stellar absorption, a large number of spaxels with low observed equivalent

  20. On the road to precision cosmology with high-redshift H II galaxies

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    We report the first results of a programme aimed at studying the properties of high-redshift galaxies with ongoing massive and dominant episodes of star formation (H II galaxies). We use the L(Hβ)-σ distance estimator based on the correlation between the ionized gas velocity dispersions and Balmer emission line luminosities of H II galaxies and Giant H II regions to trace the expansion of the Universe up to z ˜ 2.33. This approach provides an independent constraint on the equation of state of dark energy and its possible evolution with look-back time. Here we present high-dispersion (8000 to 10 000 resolution) spectroscopy of H II galaxies at redshifts between 0.6 and 2.33, obtained at the Very Large Telescope (VLT) using XShooter. Using six of these H II galaxies we obtain broad constraints on the plane Ωm-w0. The addition of 19 high-z H II galaxies from the literature improves the constraints and highlights the need for high-quality emission line profiles, fluxes and reddening corrections. The 25 high-z H II galaxies plus our local compilation of 107 H II galaxies up to z = 0.16 were used to impose further constraints. Our results are consistent with recent studies, although weaker due to the as yet small sample and low quality of the literature data of high-z H II galaxies. We show that much better and competitive constraints can be obtained using a larger sample of high-redshift H II galaxies with high quality data that can be easily obtained with present facilities like K-band Multi Object Spactrograph (KMOS) at the VLT.

  1. Effective Radius Retrieval Using Microwave and Near-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Schofield, R.; Daniel, J. S.; Solomon, S.; Miller, H. L.; Portmann, R. W.; Turner, D. D.

    2005-12-01

    The role that aerosols play in changing the radiative properties of clouds is uncertain, with even the sign of the forcing undetermined. The need for remotely sensing clouds is becoming more apparent with the desire to achieve a global estimate of the radiative forcing due to changes in clouds. A new technique of combining microwave and near-infrared spectroscopic measurements of liquid water path (LWP) and path integrated liquid water path (PLWP) respectively, to obtain effective radius information is outlined. Microwave measurements of brightness temperature are made routinely as part of the Aerosol and Radiation Measurement (ARM) program. Near-infrared measurements are conducted using spectroscopic measurements made in the wavelength region between 900 and 1700 nm. The effective radius of clouds is retrieved using an optimal estimation retrieval scheme that takes into account the measurements, their uncertainties, prior knowledge of the effective radius and its uncertainty. The technique is applied to ground-based observations of clouds made during September at Barrow, Alaska, 2004.

  2. Infrared and Near-Infrared Spectroscopy of Acetylacetone and Hexafluoroacetylacetone.

    PubMed

    Howard, Daryl L; Kjaergaard, Henrik G; Huang, Jing; Meuwly, Markus

    2015-07-23

    The infrared and near-infrared spectra of acetylacetone, acetylacetone-d8, and hexafluoroacetylacetone are characterized from experiment and computations at different levels. In the fundamental region, the intramolecular hydrogen bonded OH-stretching transition is clearly observed as a very broad band with substantial structure and located at significantly lower frequency compared to common OH-stretching frequencies. There is no clear evidence for OH-stretching overtone transitions in the near-infrared region, which is dominated by the CH-stretching overtones of the methine and methyl CH bonds. From molecular dynamics (MD) simulations, with a potential energy surface previously validated for tunneling splittings, the infrared spectra are determined and used in assigning the experimentally measured ones. It is found that the simulated spectrum in the region associated with the proton transfer mode is exquisitely sensitive to the height of the barrier for proton transfer. Comparison of the experimental and the MD simulated spectra establishes that the barrier height is around 2.5 kcal/mol, which favorably compares with 3.2 kcal/mol obtained from high-level electronic structure calculations.

  3. A near-infrared genetically targetable and activatable photosensitizer

    PubMed Central

    He, Jianjun; Wang, Yi; Missinato, Maria A.; Onuoha, Ezenwa; Perkins, Lydia A.; Watkins, Simon C.; St. Croix, Claudette M.; Tsang, Michael; Bruchez, Marcel P.

    2016-01-01

    Upon illumination, photosensitizer molecules produce reactive oxygen species (ROS) that can be utilized for functional manipulation of living cells, including protein inactivation, targeted damage introduction, and cellular ablation. Photosensitizers used to date have been either exogenous, resulting in delivery and removal challenges, or genetically encoded proteins that form or bind a native photosensitizing molecule, resulting in a constitutively active photosensitizer inside the cell. By binding a heavy-atom substituted fluorogenic dye with a genetically encoded Fluorogen Activating Protein (FAP), we demonstrate an ‘on-demand’ activated photosensitizer that produces singlet oxygen and fluorescence only when FAP-bound and activated with near infrared light. This Targeted and Activated Photosensitizer (TAPs) approach enables protein inactivation and targeted cell killing in cultured cells and rapid targeted lineage ablation in living larval and adult zebrafish. The near-infrared excitation and emission of this FAP-TAPs photosensitizer module provides a new spectral range for photosensitizer proteins, useful for imaging, manipulation and cellular ablation deep within living organisms. PMID:26808669

  4. Near-Infrared Camera Calibration for Optical Surgical Navigation.

    PubMed

    Cai, Ken; Yang, Rongqian; Lin, Qinyong; Liu, Sujuan; Chen, Huazhou; Ou, Shanxing; Huang, Wenhua; Zhou, Jing

    2016-03-01

    Near-infrared optical tracking devices, which are important components of surgical navigation systems, need to be calibrated for effective tracking. The calibration results has a direct influence on the tracking accuracy of an entire system. Therefore, the study of calibration techniques is of theoretical significance and practical value. In the present work, a systematic calibration method based on movable plates is established, which analyzes existing calibration theories and implements methods using calibration reference objects. First, the distortion model of near-infrared cameras (NICs) is analyzed in the implementation of this method. Second, the calibration images from different positions and orientations are used to establish the required linear equations. The initial values of the NIC parameters are calculated with the direct linear transformation method. Finally, the accurate internal and external parameters of the NICs are obtained by conducting nonlinear optimization. Analysis results show that the relative errors of the left and right NICs in the tracking system are 0.244 and 0.282 % for the focal lengths and 0.735 and 1.111 % for the principal points, respectively. The image residuals of the left and right image sets are both less than 0.01 pixel. The standard error of the calibration result is lower than 1, and the measurement error of the tracking system is less than 0.3 mm. The experimental data show that the proposed method of calibrating NICs is effective and can generate favorable calibration results. PMID:26728393

  5. Airborne laser systems for atmospheric sounding in the near infrared

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Jia, Huamin; Zammit-Mangion, David

    2012-06-01

    This paper presents new techniques for atmospheric sounding using Near Infrared (NIR) laser sources, direct detection electro-optics and passive infrared imaging systems. These techniques allow a direct determination of atmospheric extinction and, through the adoption of suitable inversion algorithms, the indirect measurement of some important natural and man-made atmospheric constituents, including Carbon Dioxide (CO2). The proposed techniques are suitable for remote sensing missions performed by using aircraft, satellites, Unmanned Aerial Vehicles (UAV), parachute/gliding vehicles, Roving Surface Vehicles (RSV), or Permanent Surface Installations (PSI). The various techniques proposed offer relative advantages in different scenarios. All are based on measurements of the laser energy/power incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Experimental results are presented relative to ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft above ground level. Future activities are planned to validate the atmospheric retrieval algorithms developed for CO2 column density measurements, with emphasis on aircraft related emissions at airports and other high air-traffic density environments.

  6. Near infrared photochemistry of pyruvic acid in aqueous solution.

    PubMed

    Larsen, Molly C; Vaida, Veronica

    2012-06-21

    Recent experimental and theoretical results have suggested that organic acids such as pyruvic acid, can be photolyzed in the ground electronic state by the excitation of the OH stretch vibrational overtone. These overtones absorb in the near-infrared and visible regions of the spectrum where the solar photons are plentiful and could provide a reaction pathway for the organic acids and alcohols that are abundant in the earth's atmosphere. In this paper the overtone initiated photochemistry of aqueous pyruvic acid is investigated by monitoring the evolution of carbon dioxide. In these experiments CO(2) is being produced by excitation in the near-infrared, between 850 nm and ∼1150 nm (11,765-8696 cm(-1)), where the second OH vibrational overtone (Δν = 3) of pyruvic acid is expected to absorb. These findings show not only that the overtone initiated photochemical decarboxylation reaction occurs but also that in the aqueous phase it occurs at a lower energy than was predicted for the overtone initiated reaction of pyruvic acid in the gas phase (13,380 cm(-1)). A quantum yield of (3.5 ± 1.0) × 10(-4) is estimated, suggesting that although this process does occur, it does so with a very low efficiency.

  7. Using near infrared light for deep sea mining observation systems

    NASA Astrophysics Data System (ADS)

    Lu, Huimin; Li, Yujie; Li, Xin; Yang, Jianmin; Serikawa, Seiichi

    2015-10-01

    In this paper, we design a novel deep-sea near infrared light based imaging equipment for deep-sea mining observation systems. The spectral sensitivity peaks are in the red region of the invisible spectrum, ranging from 750nm to 900nm. In addition, we propose a novel underwater imaging model that compensates for the attenuation discrepancy along the propagation path. The proposed model fully considered the effects of absorption, scattering and refraction. We also develop a locally adaptive Laplacian filtering for enhancing underwater transmission map after underwater dark channel prior estimation. Furthermore, we propose a spectral characteristic-based color correction algorithm to recover the distorted color. In water tank experiments, we made a linear scale of eight turbidity steps ranging from clean to heavily scattered by adding deep sea soil to the seawater (from 500 to 2000 mg/L). We compared the results of different turbidity underwater scene, illuminated alternately with near infrared light vs. white light. Experiments demonstrate that the enhanced NIR images have a reasonable noise level after the illumination compensation in the dark regions and demonstrates an improved global contrast by which the finest details and edges are significantly enhanced. We also demonstrate that the effective distance of the designed imaging system is about 1.5 meters, which can meet the requirement of micro-terrain observation around the deep-sea mining systems. Remotely Operated Underwater Vehicle (ROV)-based experiments also certified the effectiveness of the proposed method.

  8. Pulsed near-infrared photoacoustic spectroscopy of blood

    NASA Astrophysics Data System (ADS)

    Laufer, Jan G.; Elwell, Clare E.; Delpy, Dave T.; Beard, Paul C.

    2004-07-01

    The aim of this study was to use pulsed near infrared photoacoustic spectroscopy to determine the oxygen saturation (SO2) of a saline suspension of red blood cells in vitro. The photoacoustic measurements were made in a cuvette which formed part of a larger circuit through which the red blood cell suspension was circulated. Oxygen saturation of the red blood cell suspension was altered between 2-3% to 100% in step increments using a membrane oxygenator and at each increment an independent measurement of oxygen saturation was made using a co-oximeter. An optical parametric oscillator laser system provided nanosecond excitation pulses at a number of wavelengths in the near-infrared spectrum (740-1040nm) which were incident on the cuvette. The resulting acoustic signals were detected using a broadband (15MHz) Fabry-Perot polymer film transducer. The optical transport coefficient and amplitude were determined from the acoustic signals as a function of wavelength. These data were then used to calculate the relative concentrations of oxy- and deoxyhaemoglobin, using their known specific absorption coefficients and an empirically determined wavelength dependence of optical scattering over the wavelength range investigated. From this, the oxygen saturation of the suspension was derived with an accuracy of +/-5% compared to the co-oximeter SO2 measurements.

  9. Micro-electro-mechanically switchable near infrared complementary metamaterial absorber

    SciTech Connect

    Pitchappa, Prakash; Pei Ho, Chong; Kropelnicki, Piotr; Singh, Navab; Kwong, Dim-Lee; Lee, Chengkuo

    2014-05-19

    We experimentally demonstrate a micro-electro-mechanically switchable near infrared complementary metamaterial absorber by integrating the metamaterial layer to be the out of plane movable microactuator. The metamaterial layer is electrostatically actuated by applying voltage across the suspended complementary metamaterial layer and the stationary bottom metallic reflector. Thus, the effective spacing between the metamaterial layer and bottom metal reflector is varied as a function of applied voltage. With the reduction of effective spacing between the metamaterial and reflector layers, a strong spectral blue shift in the peak absorption wavelength can be achieved. With spacing change of 300 nm, the spectral shift of 0.7 μm in peak absorption wavelength was obtained for near infrared spectral region. The electro-optic switching performance of the device was characterized, and a striking switching contrast of 1500% was achieved at 2.1 μm. The reported micro-electro-mechanically tunable complementary metamaterial absorber device can potentially enable a wide range of high performance electro-optical devices, such as continuously tunable filters, modulators, and electro-optic switches that form the key components to facilitate future photonic circuit applications.

  10. Ischemic stroke assessment with near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Weiguo; Li, Pengcheng; Zeng, Shaoqun; Luo, Qingming; Hu, Bo

    1999-09-01

    Many authors have elucidated the theory about oxygenated hemoglobin, deoxygenated hemoglobin absorption in near-infrared spectrum. And the theory has opened a window to measure the hemodynamic changes caused by stroke. However, no proper animal model still has established to confirm the theory. The aim of this study was to validate near-infrared cerebral topography (NCT) as a practical tool and to try to trace the focal hemodynamic changes of ischemic stroke. In the present study, middle cerebral artery occlusion model and the photosensitizer induced intracranial infarct model had been established. NCT and functional magnetic resonance image (fMRI) were obtained during pre- and post-operation. The geometric shape and infarct area of NCT image was compared with the fMRI images and anatomical samples of each rat. The results of two occlusion models in different intervene factors showed the NCT for infarct focus matched well with fMRI and anatomic sample of each rats. The instrument might become a practical tool for short-term prediction of stroke and predicting the rehabilitation after stroke in real time.

  11. Near-infrared spectral methods for noninvasively measuring blood glucose

    NASA Astrophysics Data System (ADS)

    Fei, Sun; Kong, Deyi; Mei, Tao; Tao, Yongchun

    2004-05-01

    Determination of blood glucose concentrations in diabetic patients is a frequently occurring procedure and an important tool for diabetes management. Use of noninvasive detection techniques can relieve patients from the pain of frequent finger pokes and avoid the infection of disease via blood. This thesis discusses current research and analyzes the advantages and shortages of different measurement methods, including: optical methods (Transmission, Polarimetry and scattering), then, we give emphasis to analyze the technology of near-infrared (NIR) spectra. NIR spectral range 700 nm ~2300 nm was used because of its good transparency for biological tissue and presence of glucose absorption band. In this work, we present an outline of noninvasive blood glucose measurement. A near-infrared light beam is passed through the finger, and the spectral components of the emergent beam are measured using spectroscopic techniques. The device includes light sources having the wavelengths of 600 nm - 1800 nm to illuminate the tissue. Receptors associated with the light sources for receiving light and generating a transmission signal representing the light transmitted are also provided. Once a transmission signal is received by receptors, and the high and low values from each of the signals are stored in the device. The averaged values are then analyzed to determine the glucose concentration, which is displayed on the device.

  12. Near infrared transmission through clothing: applications in sensing and screening

    NASA Astrophysics Data System (ADS)

    Hutchins, D. A.; Canal, C. M.; Saleem, A.; Davis, L. A. J.; Green, R. J.

    2011-11-01

    Experiments have been performed to demonstrate that near infrared (NIR) transmission through a wide range of clothing materials is possible. Studies have shown that the characteristics of NIR transmission are affected by both the type of fibre used, and the weave pattern. A series of experiments has indicated that NIR transmission is also dependent on other variables such as fabric porosity and dye colour. It is shown that, in many cases, transmission coefficients are sufficiently high that imaging and spectroscopy of objects hidden behind clothing samples should be possible. However, while transmission through clothing at NIR wavelengths in the 750-1,700 nm range is often more effective than in the visible or IR regions, the fabrics themselves will modify the transmitted signal in terms of spatial effects, intensity and spectral content. The paper also describes the possible use of near infrared signals to identify objects that are hidden behind clothing layers. This can be done using spectroscopy. It is important, however, to distinguish the various contributions that exist within the backscattered signal. A set of careful laboratory experiments have demonstrated that transmission through a set of different clothing fabrics does modify the spectral content of signals, but that the spectrum of a particular chemical can still be identified, provided certain steps are taken. These involve a set of careful calibration measurements, and the use of processing techniques for the retrieval of data. It will be shown that this is possible for both granular solids and selected liquids.

  13. The Puzzlingly Small Ca II Triplet Absorption in Elliptical Galaxies

    NASA Astrophysics Data System (ADS)

    Saglia, R. P.; Maraston, Claudia; Thomas, Daniel; Bender, Ralf; Colless, Matthew

    2002-11-01

    We measure the central values (within Re/8) of the Ca II triplet line indices CaT* and CaT and the Paschen index PaT at 8600 Å for a 93% complete sample of 75 nearby early-type galaxies with BT<12 mag and Vgal<2490 km s-1. We find that the values of CaT* are constant to within 5% over the range of central velocity dispersions 100 km s-1<=σ<=340 km s-1, while the PaT (and CaT) values are mildly anticorrelated with σ. Using simple and composite stellar population models, we show the following: (1) The measured CaT* and CaT are lower than expected from simple stellar population (SSP) models with Salpeter initial mass functions (IMFs) and with metallicities and ages derived from optical Lick (Fe, Mg, and Hβ) indices. Uncertainties in the calibration, the fitting functions, and the SSP modeling taken separately cannot explain the discrepancy. On average, the observed PaT values are within the range allowed by the models and the large uncertainties in the fitting functions. (2) The steepening of the IMF at low masses required to lower the CaT* and CaT indices to the observed values is incompatible with the measured FeH index at 9916 Å and the dynamical mass-to-light ratios of elliptical galaxies. (3) Composite stellar populations with a low-metallicity component reduce the disagreement, but rather artificial metallicity distributions are needed. Another explanation may be that calcium is indeed underabundant in elliptical galaxies.

  14. Detection of faint broad emission lines in type 2 AGN: I. Near infrared observations and spectral fitting

    NASA Astrophysics Data System (ADS)

    Onori, F.; La Franca, F.; Ricci, F.; Brusa, M.; Sani, E.; Maiolino, R.; Bianchi, S.; Bongiorno, A.; Fiore, F.; Marconi, A.; Vignali, C.

    2016-09-01

    We present medium resolution near infrared spectroscopic observations of 41 obscured and intermediate class AGN (type 2, 1.9 and 1.8; AGN2) with redshift z ≲0.1, selected from the Swift/BAT 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near infrared spectral properties and have been executed using ISAAC/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of ˜30 per resolution element. For those objects observed with X-shooter we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with FWHM >800 km s-1. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components found in AGN2 has a significantly (a factor 2) smaller FWHM if compared with a control sample of type 1 AGN.

  15. Synthesis of Non-blinking Semiconductor Quantum Dots Emitting in the Near-Infrared

    SciTech Connect

    Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei; Park, Young-Shin; Htoon, Han; Hollingsworth, Jennifer A.

    2012-06-21

    Our previous work demonstrates that Quasi-Type II CdSe/CdS core-shell quantum dots with thick shells (3-5 nm) exhibit unique photophysical characteristics, including improved chemical robustness over typical thin-shelled core/shell systems and the elimination of blinking through suppression of nonradiative Auger recombination. Here we describe a new thick-shelled heterostructure, InP/CdS, which exhibits a Type II bandgap alignment producing near-infrared (NIR) emission. Samples with a range of shell thicknesses were synthesized, enabling shell-thickness-dependent study of the absorbance and emission spectra, fluorescence lifetimes, and quantum yields. InP/CdS/ZnS core/shell/shell structures were also synthesized to reduce cadmium exposure for applications in the biological environment. Single particle spectroscopy indicates reduced blinking and improved photostability with increasing shell thickness, resulting in thick-shelled dots that are appropriate for single-particle tracking measurements with NIR emission.

  16. HIGH-CONTRAST NEAR-INFRARED IMAGING POLARIMETRY OF THE PROTOPLANETARY DISK AROUND RY TAU

    SciTech Connect

    Takami, Michihiro; Karr, Jennifer L.; Kim, Hyosun; Chou, Mei-Yin; Hashimoto, Jun; Kandori, Ryo; Kusakabe, Nobuhiko; Kwon, Jungmi; Wisniewski, John; Henning, Thomas; Brandner, Wolfgang; Grady, Carol A.; Hodapp, Klaus W.; Kudo, Tomoyuki; Itoh, Yoichi; Momose, Munetake; Mayama, Satoshi; Currie, Thayne; Follette, Katherine B.; Abe, Lyu; and others

    2013-08-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at the H band at a high resolution ({approx}0.''05) for the first time, using Subaru/HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  17. High-Contrast Near-Infrared Imaging Polarimetry of the Protoplanetary Disk around RY Tau

    NASA Technical Reports Server (NTRS)

    Takami, Michihiro; Karr, Jennifer L.; Hashimoto, Jun; Kim, Hyosun; Wisenewski, John; Henning, Thomas; Grady, Carol; Kandori, Ryo; Hodapp, Klaus W.; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Chou, Mei-yin; Itoh, Yoichi; Momose, Mumetake; Mayama, Satoshi; Currie, Thayne; Follette, Katherine B.; Kwon, Jungmi; Abe, Lyu; Brandner, Wolfgang; Brandt, Timothy D.; Carson, Joseph; Egner, Sebastian E.; McElwain, Michael W.; Serabyn, Eugene

    2013-01-01

    We present near-infrared coronagraphic imaging polarimetry of RY Tau. The scattered light in the circumstellar environment was imaged at H-band at a high resolution (approx. 0.05) for the first time, using Subaru-HiCIAO. The observed polarized intensity (PI) distribution shows a butterfly-like distribution of bright emission with an angular scale similar to the disk observed at millimeter wavelengths. This distribution is offset toward the blueshifted jet, indicating the presence of a geometrically thick disk or a remnant envelope, and therefore the earliest stage of the Class II evolutionary phase. We perform comparisons between the observed PI distribution and disk models with: (1) full radiative transfer code, using the spectral energy distribution (SED) to constrain the disk parameters; and (2) monochromatic simulations of scattered light which explore a wide range of parameters space to constrain the disk and dust parameters. We show that these models cannot consistently explain the observed PI distribution, SED, and the viewing angle inferred by millimeter interferometry. We suggest that the scattered light in the near-infrared is associated with an optically thin and geometrically thick layer above the disk surface, with the surface responsible for the infrared SED. Half of the scattered light and thermal radiation in this layer illuminates the disk surface, and this process may significantly affect the thermal structure of the disk.

  18. PENETRATING THE HOMUNCULUS-NEAR-INFRARED ADAPTIVE OPTICS IMAGES OF ETA CARINAE

    SciTech Connect

    Artigau, Etienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-15

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the 'butterfly nebula', outlined by bright Br{gamma} and H{sub 2} emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in {eta} Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10{sup 0}-20{sup 0} above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star.

  19. Fossil group origins. II. Unveiling the formation of the brightest group galaxies through their scaling relations

    NASA Astrophysics Data System (ADS)

    Méndez-Abreu, J.; Aguerri, J. A. L.; Barrena, R.; Sánchez-Janssen, R.; Boschin, W.; Castro-Rodriguez, N.; Corsini, E. M.; Del Burgo, C.; D'Onghia, E.; Girardi, M.; Iglesias-Páramo, J.; Napolitano, N.; Vilchez, J. M.; Zarattini, S.

    2012-01-01

    Context. Fossil systems are galaxy associations dominated by a relatively isolated, bright elliptical galaxy, surrounded by a group of smaller galaxies lacking L∗ objects. Because of this extreme environment, fossil groups (FGs) are ideal laboratories for studying the mass assembly of brightest group galaxies (BGGs). Aims: We analyzed the near-infrared photometric and structural properties of a sample of 20 BGGs present in FGs to better understand their formation mechanisms. They represent the largest sample studied to date. Methods.Ks-band deep images were used to study the structural properties of our sample galaxies. Their surface-brightness distribution was fitted to a Sérsic profile using the GASP2D algorithm. Then, the standard scaling relations were derived for the first time for these galaxies and compared with those of normal ellipticals and brightest cluster galaxies in non-fossil systems. Results: The BGGs presented in this study represent a subset of the most massive galaxies in the Universe. We find that their ellipticity profiles are continuously increasing with the galactocentric radius. Our fossil BCGs follow closely the fundamental plane described by normal ellipticals. However, they depart from both the log σ0 vs. log LKs and log re vs. log LKs relations described by intermediate-mass ellipticals. This occurs in the sense that our BGGs have larger effective radii and smaller velocity dispersions than those predicted by these relations. We also find that more elliptical galaxies systematically deviate from the previous relations, while rounder objects do not. No similar correlation was found with the Sérsic index. Conclusions: The derived scaling relations can be interpreted in terms of the formation scenario of the BGGs. Because our BGGs follow the fundamental plane tilt but have larger effective radii than expected for intermediate-mass ellipticals, we suggest that they only went through dissipational mergers in an early stage of their

  20. Classification of burn injuries using near-infrared spectroscopy.

    PubMed

    Sowa, Michael G; Leonardi, Lorenzo; Payette, Jeri R; Cross, Karen M; Gomez, Manuel; Fish, Joel S

    2006-01-01

    Early surgical management of those burn injuries that will not heal spontaneously is critical. The decision to excise and graft is based on a visual assessment that is often inaccurate but yet continues to be the primary means of grading the injury. Superficial and intermediate partial-thickness injuries generally heal with appropriate wound care while deep partial- and full-thickness injuries generally require surgery. This study explores the possibility of using near-infrared spectroscopy to provide an objective and accurate means of distinguishing shallow injuries from deeper burns that require surgery. Twenty burn injuries are studied in five animals, with burns covering <1% of the total body surface area. Carefully controlled superficial, intermediate, and deep partial-thickness injuries as well as full-thickness injuries could be studied with this model. Near-infrared reflectance spectroscopy was used to evaluate these injuries 1 to 3 hours after the insult. A probabilistic model employing partial least-squares logistic regression was used to determine the degree of injury, shallow (superficial or intermediate partial) from deep (deep partial and full thickness), based on the reflectance spectrum of the wound. A leave-animal-out cross-validation strategy was used to test the predictive ability of a 2-latent variable, partial least-squares logistic regression model to distinguish deep burn injuries from shallow injuries. The model displayed reasonable ranking quality as summarized by the area under the receiver operator characteristics curve, AUC = 0.879. Fixing the threshold for the class boundaries at 0.5 probability, the model sensitivity (true positive fraction) to separate deep from shallow burns was 0.90, while model specificity (true negative fraction) was 0.83. Using an acute porcine model of thermal burn injuries, the potential of near-infrared spectroscopy to distinguish between shallow healing burns and deeper burn injuries was demonstrated. While

  1. Probing Dust Formation Around Evolved Stars with Near-Infrared Interferometry

    NASA Astrophysics Data System (ADS)

    Sargent, B.; Srinivasan, S.; Riebel, D.; Meixner, M.

    2014-09-01

    Near-infrared interferometry holds great promise for advancing our understanding of the formation of dust around evolved stars. For example, the Magdalena Ridge Observatory Interferometer (MROI), which will be an optical/near-infrared interferometer with down to submilliarcsecond resolution, includes studying stellar mass loss as being of interest to its Key Science Mission. With facilities like MROI, many questions relating to the formation of dust around evolved stars may be probed. How close to an evolved star such as an asymptotic giant branch (AGB) or red supergiant (RSG) star does a dust grain form? Over what temperature ranges will such dust form? How does dust formation temperature and distance from star change as a function of the dust composition (carbonaceous versus oxygen-rich)? What are the ranges of evolved star dust shell geometries, and does dust shell geometry for AGB and RSG stars correlate with dust composition, similar to the correlation seen for planetary nebula outflows? At what point does the AGB star become a post-AGB star, when dust formation ends and the dust shell detaches? Currently we are conducting studies of evolved star mass loss in the Large Magellanic Cloud using photometry from the Surveying the Agents of a Galaxy's Evolution (SAGE; PI: M. Meixner) Spitzer Space Telescope Legacy program. We model this mass loss using the radiative transfer program 2Dust to create our Grid of Red supergiant and Asymptotic giant branch ModelS (GRAMS). For simplicity, we assume spherical symmetry, but 2Dust does have the capability to model axisymmetric, non-spherically-symmetric dust shell geometries. 2Dust can also generate images of models at specified wavelengths. We discuss possible connections of our GRAMS modeling using 2Dust of SAGE data of evolved stars in the LMC and also other data on evolved stars in the Milky Way's Galactic Bulge to near-infrared interferometric studies of such stars. By understanding the origins of dust around evolved

  2. Probing Reionization at z >~ 7 with HST's Near-Infrared Grisms

    NASA Astrophysics Data System (ADS)

    Schmidt, Kasper B.

    The epoch of reionization, i.e. the phase transition of the inter-galactic medium from neutral to fully ionized, is essential for our understanding of the evolution of the Universe and the formation of the first stars and galaxies. The Grism Lens-Amplified Survey from Space (GLASS) has obtained spectra of ten thousands of objects in and behind 10 massive galaxy clusters, including the six Hubble Frontier Fields. The grism spectroscopy from GLASS results in hundreds of spectra of z >~ 7 galaxy candidates. Taking advantage of the lensing magnification from the foreground clusters, the GLASS spectra reaches unprecedented depths in the near-infrared with observed flux limits of ~ 5 × 10-18erg/s/cm2 before correcting for the lens magnification. This has resulted in several Lyα detections at z ~ 7 and tight limits on the emission line fluxes for non-detections. From an ensemble of different photometric selections, we have assembled more than 150 z >~ 7 galaxy candidates from six of the ten GLASS clusters. Among these more than 20 objects show emission lines consistent with being Lyα at z >~ 7. The spatial extent of Lyα estimated from a stack of the most promising Lyα emitters at = 7.2 is consistent with the spatial extent of the UV continuum emission. From the stack we obtain upper limits on the emission line ratios between prominent rest-frame UV emission lines, finding that f CIV/f Lyα <~ 0.32 and f CIII]/f Lyα <~ 0.23 in good agreement with values published in the literature.

  3. Near-infrared response of a single carbon nanocoil.

    PubMed

    Ma, He; Pan, Lujun; Zhao, Qin; Peng, Wei

    2013-02-01

    The near-infrared photoresponse of a single suspended carbon nanocoil (CNC) is investigated. Under the irradiation of a 785 nm laser beam, the photoresponse is generated in the voltage-biased CNC. At a voltage of 50 mV, the ratio of the conductance change to the initial conductance, which is defined as the sensitivity in this paper, can reach 22% and the typical response time is 5 ms. It is found from the changes of photoresponse with pressure and with the laser power that the photoresponse of the CNC is mainly attributed to the bolometric effect. Because of the increase of Joule heating, the sensitivity reduces with the elevation of the bias voltage. However, the responsivity increases with the increase of the bias voltage, which is opposite to the change of the sensitivity. The maximum responsivity of the single CNC IR sensor is 0.22 A W(-1). PMID:23288029

  4. ANIR: Atacama near infrared camera for Paschen α imaging

    NASA Astrophysics Data System (ADS)

    Motohara, Kentaro; Mitani, Natsuko; Sako, Shigeyuki; Uchimoto, Yuka K.; Toshikawa, Koji; Yamamuro, Tomoyasu; Handa, Toshihiro; Tanaka, Masuo; Aoki, Tsutomu; Doi, Mamoru; Kawara, Kimiaki; Kohno, Kotaro; Minezaki, Takeo; Miyata, Takashi; Soyano, Takao; Tanabe, Toshihiko; Tarusawa, Ken'ichi; Yoshii, Yuzuru

    2008-07-01

    We have been developing a near infrared camera called ANIR (Atacama Near InfraRed camera), for the University of Tokyo Atacama 1.0m telescope installed at the summit of Co. Chajnantor (5640m altitude) in Northern Chile. The major aim of this camera is to carry out an imaging survey in Paschen α emission line (1.8751μm) from the ground for the first time. The camera is based on a PACE-HAWAII2 array with an Offner relay optics for re-imaging, and field of view is 5.'3 × 5.'3 with pixel scale of 0."308/pix. It is scheduled to see first light in the end of 2008, and start the Paschen α/β survey of the Galactic plane in 2009.

  5. Semiconductor plasmonic metamaterials for near-infrared and telecommunication wavelength

    NASA Astrophysics Data System (ADS)

    Naik, Gururaj V.; Shalaev, Vladimir M.; Boltasseva, Alexandra

    2010-08-01

    Plasmonic materials have conventionally been gold and silver in optical frequencies. However, these conventional metals in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses. With the advent of metamaterials, these metals pose a serious bottle-neck in the performances of metamaterial-based devices not only due to the large losses associated with them in the NIR and visible wavelengths, but also their magnitudes of real permittivity are too large. Both of these problems could be solved by using semiconductors as plasmonic materials. Heavily doped zinc oxide and indium oxide can exhibit losses that are nearly four times smaller than silver at the telecommunication wavelength with small negative real permittivity. In this paper, we present the development of a low loss semiconductor plasmonic material, aluminum doped zinc oxide (AZO).

  6. Extended near-infrared emission from visual reflection nebulae

    NASA Technical Reports Server (NTRS)

    Sellgren, K.; Werner, M. W.; Dinerstein, H. L.

    1983-01-01

    Extended near infrared (2 to 5 microns) emission was observed from three visual reflection nebulae, NGC 7023, 2023, and 2068. The emission from each nebula consists of a smooth continuum, which can be described by a greybody with a color temperature of 1000 K, and emission features at 3.3 and 3.4 microns. The continuum emission cannot be explained by free-free emission, reflected light, or field stars, or by thermal emission from grains, with commonly accepted ratios of infrared to ultraviolet emissivities, which are in equilibrium with the stellar radiation field. A possible explanation is thermal emission from grains with extremely low ratios of infrared to ultraviolet emissivities, or from grains with a temperature determined by mechanisms other than equilibrium radiative heating. Another possibility is continuum fluorescence. Previously announced in STAR N83-25629

  7. Extended near infrared emission from visual reflection nebulae

    NASA Technical Reports Server (NTRS)

    Sellgren, K.; Werner, M. W.; Dinerstein, H. L.

    1982-01-01

    Extended near infrared (2 to 5 microns) emission was observed from three visual reflection nebulae, NGC 7023, 2023, and 2068. The emission from each nebula consists of a smooth continuum, which can be described by a greybody with a color temperature of 1000 K, and emission features at 3.3 and 3.4 microns. The continuum emission cannot be explained by free-free emission, reflected light, or field stars, or by thermal emission from grains, with commonly accepted ratios of infrared to ultraviolet emissivities, which are in equilibrium with the stellar radiation field. A possible explanation is thermal emission from grains with extremely low ratios of infrared to ultraviolet emissivities, or from grains with a temperature determined by mechanisms other than equilibrium radiative heating. Another possibility is continuum fluorescence.

  8. Tailored Near-Infrared Contrast Agents for Image Guided Surgery

    PubMed Central

    Njiojob, Costyl N.; Owens, Eric A.; Narayana, Lakshminarayana; Hyun, Hoon; Choi, Hak Soo; Henary, Maged

    2015-01-01

    The success of near-infrared (NIR) fluorescence to be employed for intraoperative imaging relies on the ability to develop a highly stable, NIR fluorescent, nontoxic, biocompatible, and highly excreted compound that retains a reactive functionality for conjugation to a cancer-recognizing peptide. Herein, systematic modifications to previously detailed fluorophore ZW800-1 are explored. Specific modifications, including the isosteric replacement of the O atom of ZW800-1, include nucleophilic amine and sulfur species attached to the heptamethine core. These novel compounds have shown similar satisfactory results in biodistribution and clearance while also expressing increased stability in serum. Most importantly, all of the synthesized and evaluated compounds display a reactive functionality (either a free amino group or carboxylic acid moiety) for further bioconjugation. The results obtained from the newly prepared derivatives demonstrate that the central substitution with the studied linking agents retains the ultralow background in vivo performance of the fluorophores regardless of the total net charge. PMID:25711712

  9. Fluorescence polarization standard for near infrared spectroscopy and microscopy.

    PubMed

    Luchowski, Rafal; Sarkar, Pabak; Bharill, Shashank; Laczko, Gabor; Borejdo, Julian; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2008-11-20

    We present studies of polarized absorption [linear dichroism (LD)] and fluorescence polarization of the styryl derivative (LDS 798) embedded in oriented poly(vinyl alcohol) (PVA) films. These films were oriented by progressive stretching up to eight folds. Both vertical and horizontal components of absorptions and fluorescence were measured and dichroic ratios were determined for different film stretching ratios. The dichroic ratio and fluorescence anisotropy values were analyzed as a function of PVA film stretching ratio by fitting according to the previously developed theory. For maximum stretching ratios, exceptionally high anisotropy (approximately 0.8) and polarization (approximately 0.9) values have been measured. The stretched films have high polarization values also for isotropic excitation in a wide spectral range (500-700 nm). Such films can be conveniently used as high polarization standards and we envision they will also have applications in near infrared (NIR) imaging microscopy, where they can be used for correcting an instrumental factor in polarization measurements.

  10. Visible and near infrared reflectances measured from laboratory ice clouds.

    PubMed

    Barkey, Brian; Liou, K N

    2008-05-01

    We present laboratory results of the 0.68 microm visible (VIS) and 1.617 microm near infrared (NIR) reflectances typically used for inferring optical depth and ice crystal size from satellite radiometers, from ice clouds generated in a temperature controlled column cloud chamber. Two types of ice crystals were produced in this experiment: small columns and dendrites with mean maximum dimensions of about 17 and 35 microm. Within experimental uncertainty, the measured reflectances from ice clouds at both wavelengths agree reasonably well with the theoretical results computed from the plane-parallel adding-doubling method for radiative transfer using the measured ice particle morphology. We demonstrate that laboratory scattering and reflectance data for thin ice clouds with optical depths less than 0.4 can be used for validation of the thin cirrus optical depth and ice crystal size that have been routinely retrieved from the satellite VIS-NIR two channel pair.

  11. Unique-sample selection via near-infrared spectral subtraction

    SciTech Connect

    Honigs, D.E.; Hieftje, G.M.; Mark, H.L.; Hirschfeld, T.B.

    1985-10-01

    A method is described and tested for improving the training sample set in near-infrared diffuse-reflectance analysis (NIRA). Utilizing linear algebra techniques similar to spectral subtraction, this method selects the most spectrally unique samples from those in a larger pool. Upon being analyzed, these spectrally unique samples are found to have a significantly larger variation in their chemical compositions than the pool of samples from which they were selected. When the spectrally unique samples are incorporated into a NIRA training set, the resulting calibration is improved in two ways: first, the larger variations in sample composition help to make a NIRA calibration more robust and less subject to unexpected variations in the sample matrix; second, use of the spectrally unique samples reduces the time and effort involved in developing a NIRA method of analysis. 13 references, 2 figures, 7 tables.

  12. Combining near-infrared illuminants to optimize venous imaging

    NASA Astrophysics Data System (ADS)

    Paquit, Vincent; Price, Jeffery R.; Mériaudeau, Fabrice; Tobin, Kenneth W., Jr.; Ferrell, Thomas L.

    2007-03-01

    The first and perhaps most important phase of a surgical procedure is the insertion of an intravenous (IV) catheter. Currently, this is performed manually by trained personnel. In some visions of future operating rooms, however, this process is to be replaced by an automated system. We previously presented work for localizing near-surface veins via near-infrared (NIR) imaging in combination with structured light ranging for surface mapping and robotic guidance. In this paper, we describe experiments to determine the best NIR wavelengths to optimize vein contrast for physiological differences such as skin tone and/or the presence of hair on the arm or wrist surface. For illumination, we employ an array of NIR LEDs comprising six different wavelength centers from 740nm to 910nm. We capture imagery of each subject under every possible combination of illuminants and determine the optimal combination of wavelengths for a given subject to maximize vein contrast using linear discriminant analysis.

  13. Detecting counterfeit antimalarial tablets by near-infrared spectroscopy.

    PubMed

    Dowell, Floyd E; Maghirang, Elizabeth B; Fernandez, Facundo M; Newton, Paul N; Green, Michael D

    2008-11-01

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discriminating between counterfeit and genuine artesunate antimalarial tablets. Using NIRS, we found that artesunate tablets could be identified as genuine or counterfeit with high accuracy. Multivariate classification models indicated that this discriminatory ability was based, at least partly, on the presence or absence of spectral signatures related to artesunate. This technique can be field-portable and requires little training after calibrations are developed, thus showing great promise for rapid and accurate fake detection. PMID:18703302

  14. Multivariate analysis of coconut residues by near infrared spectroscopy.

    PubMed

    Rambo, M K D; Alves, A R; Garcia, W T; Ferreira, M M C

    2015-06-01

    Near infrared (NIR) spectroscopy was used to determine the content of Klason lignin, acid-soluble lignin, total lignin, extractives, ash, acid-insoluble residue, glucose, xylose, rhamnose, galactose, arabinose, mannose and total sugars in coconut residues. The samples were analyzed at several processing stages: wet unground (WU), dried unground (DU) and dried and sieved (DS). Partial least squares models were built, and the models for the analytes exhibited R(2)>0.80, with the exceptions of rhamnose, arabinose, galactose, mannose and ash from all fractions, and the lignin content from the WU fraction, which were predicted poorly (R(2)<0.70). There were some significant differences between the models for the main lignocellulosic components at the various stages of biomass. These results proved that NIR spectroscopy is useful for analysis at biorefineries, and it can be used as a faster and more economical alternative to the standard methods.

  15. Near-Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    SciTech Connect

    Bwambok, David; El-Zahab, Bilal; Challa, Santhosh; Li, Min; Chandler, Lin; Baker, Gary A; Warner, Isiah M

    2009-01-01

    Herein, we report on near-infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS.

  16. Near-infrared imaging of demineralization under sealants

    NASA Astrophysics Data System (ADS)

    Tom, Henry; Simon, Jacob C.; Chan, Kenneth H.; Darling, Cynthia L.; Fried, Daniel

    2014-07-01

    Previous studies have shown that near-infrared (NIR) reflectance and transillumination imaging can be used to acquire high contrast images of early caries lesions and composite restorative materials. The aim of the study was to determine the optimum NIR wavelengths for imaging demineralized areas under dental sealants. Fifteen natural human premolars and molars with occlusal lesions were used in this in vitro study. Images before and after application of sealants were acquired using NIR reflectance and NIR transillumination at wavelengths of 1300, 1460, and 1500 to 1700 nm. Images were also acquired using polarization sensitive optical coherence tomography (OCT) for comparison. The highest contrast for NIR reflectance was at 1460 nm and 1500 to 1700 nm. These NIR wavelengths are coincident with higher water absorption. The clear Delton sealant investigated was not visible in either copolarization or cross-polarization OCT images. The wavelength region between 1500 and 1700 nm yielded the highest contrast of lesions under sealants for NIR reflectance measurements.

  17. Functional near-infrared spectroscopy studies in children

    PubMed Central

    2012-01-01

    Psychosomatic and developmental behavioral medicine in pediatrics has been the subject of significant recent attention, with infants, school-age children, and adolescents frequently presenting with psychosomatic, behavioral, and psychiatric symptoms. These may be a consequence of insecurity of attachment, reduced self-confidence, and peer -relationship conflicts during their developmental stages. Developmental cognitive neuroscience has revealed significant associations between specific brain lesions and particular cognitive dysfunctions. Thus, identifying the biological deficits underlying such cognitive dysfunction may provide new insights into therapeutic prospects for the management of those symptoms in children. Recent advances in noninvasive neuroimaging techniques, and especially functional near-infrared spectroscopy (NIRS), have contributed significant findings to the field of developmental cognitive neuroscience in pediatrics. We present here a comprehensive review of functional NIRS studies of children who have developed normally and of children with psychosomatic and behavioral disorders. PMID:22433235

  18. Tailored near-infrared contrast agents for image guided surgery.

    PubMed

    Njiojob, Costyl N; Owens, Eric A; Narayana, Lakshminarayana; Hyun, Hoon; Choi, Hak Soo; Henary, Maged

    2015-03-26

    The success of near-infrared (NIR) fluorescence to be employed for intraoperative imaging relies on the ability to develop a highly stable, NIR fluorescent, nontoxic, biocompatible, and highly excreted compound that retains a reactive functionality for conjugation to a cancer-recognizing peptide. Herein, systematic modifications to previously detailed fluorophore ZW800-1 are explored. Specific modifications, including the isosteric replacement of the O atom of ZW800-1, include nucleophilic amine and sulfur species attached to the heptamethine core. These novel compounds have shown similar satisfactory results in biodistribution and clearance while also expressing increased stability in serum. Most importantly, all of the synthesized and evaluated compounds display a reactive functionality (either a free amino group or carboxylic acid moiety) for further bioconjugation. The results obtained from the newly prepared derivatives demonstrate that the central substitution with the studied linking agents retains the ultralow background in vivo performance of the fluorophores regardless of the total net charge.

  19. Venus as Viewed Through Violet and Near Infrared Filters

    NASA Technical Reports Server (NTRS)

    1991-01-01

    These two Galileo images of Venus show the global structure of cloud patterns at two different depths in the upper cloud layers. The large bluish image, taken through the violet filter, shows patterns at the very top of Venus' main sulfuric acid haze layer. The subsolar point is to the right, not far from the limb; the atmospheric flow runs to the left from there. The small red image, taken through a near infrared filter, shows the cloud patterns several miles below the visible cloud tops. The colors shown are artificial; the images were enhanced at the National Optical Astronomy Observatories, Tucson, Arizona. The Galileo Project is managed for NASA by the Jet Propulsion Laboratory.

  20. Cardiac tissue characterization using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh Moon, Rajinder; Hendon, Christine P.

    2014-03-01

    Cardiac tissue from swine and canine hearts were assessed using diffuse reflectance near-infrared spectroscopy (NIRS) ex vivo. Slope measured between 800-880 nm reflectance was found to reveal differences between epicardial fat and normal myocardium tissue. This parameter was observed to increase monotonically from measurements obtained from the onset of radiofrequency ablation (RFA). A sheathe-style fiber optic catheter was then developed to allow real-time sampling of the zone of resistive heating during RFA treatment. A model was developed and used to extract changes in tissue absorption and reduced scattering based on the steady-state diffusion approximation. It was found that key changes in tissue optical properties occur during application of RF energy and can be monitored using NIRS. These results encourage the development of NIRS integrated catheters for real-time guidance of the cardiac ablation treatment.

  1. Analysis of silage composition by near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Reeves, James B., III; Blosser, Timothy H.; Colenbrander, V. F.

    1991-02-01

    Two studies were performed to investigate the feasibility of using near infrared reflectance spectroscopy (NIRS) with undried silages. In the first study silages were analyzed for major components (e. g. dry matter crude protein and other forms of nitrogen fiber and in vitro digestible dry matter) and short chain fatty acids (SCFA). NIRS was found to operate satisfactorily except for some forms of nitrogen and SCFA. In study two various methods of grinding spectral regions and sample presentation were examined. Undried Wiley ground samples in a rectangular cell gave the best overall results for non-dry ice undried grinds with wavelengths between 1100 and 2498 nm. Silages scanned after drying however produced the best results. Intact samples did not perform as well as ground samples and wavelengths below 1100 nm were of little use. 2 .

  2. Review of functional near-infrared spectroscopy in neurorehabilitation.

    PubMed

    Mihara, Masahito; Miyai, Ichiro

    2016-07-01

    We provide a brief overview of the research and clinical applications of near-infrared spectroscopy (NIRS) in the neurorehabilitation field. NIRS has several potential advantages and shortcomings as a neuroimaging tool and is suitable for research application in the rehabilitation field. As one of the main applications of NIRS, we discuss its application as a monitoring tool, including investigating the neural mechanism of functional recovery after brain damage and investigating the neural mechanisms for controlling bipedal locomotion and postural balance in humans. In addition to being a monitoring tool, advances in signal processing techniques allow us to use NIRS as a therapeutic tool in this field. With a brief summary of recent studies investigating the clinical application of NIRS using motor imagery task, we discuss the possible clinical usage of NIRS in brain-computer interface and neurofeedback. PMID:27429995

  3. Near infrared spectroscopy in the development of solid dosage forms.

    PubMed

    Räsänen, Eetu; Sandler, Niklas

    2007-02-01

    The use of near infrared (NIR) spectroscopy has rapidly grown partly due to demands of process analytical applications in the pharmaceutical industry. Furthermore, newest regulatory guidelines have advanced the increase of the use of NIR technologies. The non-destructive and non-invasive nature of measurements makes NIR a powerful tool in characterization of pharmaceutical solids. These benefits among others often make NIR advantageous over traditional analytical methods. However, in addition to NIR, a wide variety of other tools are naturally also available for analysis in pharmaceutical development and manufacturing, and those can often be more suitable for a given application. The versatility and rapidness of NIR will ensure its contribution to increased process understanding, better process control and improved quality of drug products. This review concentrates on the use of NIR spectroscopy from a process research perspective and highlights recent applications in the field.

  4. Componential distribution analysis of food using near infrared ray image

    NASA Astrophysics Data System (ADS)

    Yamauchi, Hiroki; Kato, Kunihito; Yamamoto, Kazuhiko; Ogawa, Noriko; Ohba, Kimie

    2008-11-01

    The components of the food related to the "deliciousness" are usually evaluated by componential analysis. The component content and type of components in the food are determined by this analysis. However, componential analysis is not able to analyze measurements in detail, and the measurement is time consuming. We propose a method to measure the two-dimensional distribution of the component in food using a near infrared ray (IR) image. The advantage of our method is to be able to visualize the invisible components. Many components in food have characteristics such as absorption and reflection of light in the IR range. The component content is measured using subtraction between two wavelengths of near IR light. In this paper, we describe a method to measure the component of food using near IR image processing, and we show an application to visualize the saccharose in the pumpkin.

  5. Near-infrared Molecular Probes for In Vivo Imaging

    PubMed Central

    Zhang, Xuan; Bloch, Sharon; Akers, Walter; Achilefu, Samuel

    2012-01-01

    Cellular and tissue imaging in the near-infrared (NIR) wavelengths between 700 and 900 nm is advantageous for in vivo because of the low absorption of biological molecules in this region. This Unit presents protocols for small animal imaging using planar and fluorescence lifetime imaging techniques. Included is an overview of NIR fluorescence imaging of cells and small animals using NIR organic fluorophores, nanoparticles, and multimodal imaging probes. The development, advantages, and application of NIR fluorescent probes that have been used for in vivo imaging are also summarized. The use of NIR agents in conjunction with visible dyes and considerations in selecting imaging agents are discussed. We conclude with practical considerations for the use of these dyes in cell and small animal imaging applications. PMID:22470154

  6. Modeling of near infrared pulsed laser sintering of metallic powders

    NASA Astrophysics Data System (ADS)

    Fischer, Pascal; Romano, Valerio; Weber, Heinz P.; Karapatis, N. P.; André, C.; Glardon, R.

    2003-11-01

    Using pulsed near infrared laser radiation for selective laser sintering bears several advantages compared to cw sintering such as low requried average power, less residual heat and improved lateral precision. By adapting the pulse length (and thus the heat diffusion length during the pulse) to the grain size of the used metal powder, the laser pulse energy can mainly by deposited in the skin of the powder particles where heating and melting is obtained, whereas the centers of the grains remain at much lower temperature and act as heat sinks after consolidation. The model described here was numerically implemented and experimentally tested with a pulsed Nd:YAG laser on titanium powder. The results of the model predictions and the performed experiments are in good agreement.

  7. Non-invasive neuroimaging using near-infrared light

    NASA Technical Reports Server (NTRS)

    Strangman, Gary; Boas, David A.; Sutton, Jeffrey P.

    2002-01-01

    This article reviews diffuse optical brain imaging, a technique that employs near-infrared light to non-invasively probe the brain for changes in parameters relating to brain function. We describe the general methodology, including types of measurements and instrumentation (including the tradeoffs inherent in the various instrument components), and the basic theory required to interpret the recorded data. A brief review of diffuse optical applications is included, with an emphasis on research that has been done with psychiatric populations. Finally, we discuss some practical issues and limitations that are relevant when conducting diffuse optical experiments. We find that, while diffuse optics can provide substantial advantages to the psychiatric researcher relative to the alternative brain imaging methods, the method remains substantially underutilized in this field.

  8. Characteristic wavelength of textile fiber in near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Feng, Hongnian; Jin, Shangzhong; Gan, Bin

    2006-01-01

    Near Infrared (NIR) spectroscopy in the region from 1300 to 1700nm, coupled with multivariate analytic statistical techniques, have been used to predict the chemical properties of textile fiber. Molecule absorbs electromagnetic wave with especial wavelength, which leads to bring characteristic absorption spectrum. Characteristic wavelength is the most important parameter in NIR detection. How to select characteristic wavelength is the key to NIR measure. Different mathematical methods are used to find relationship between the NIR absorption spectrum and the chemical properties of the textile fiber. We adopt stepwise multiple linear regression (SMLR) to select characteristic wavelength. As objective condition is limited, this article only refers to cotton and terylene. By computing correlation coefficient, we establish calibration equation with the smoothed absorbance data. Finally, the bias was controlled under 6%. Then, we find that NIR can be used to carry on qualitative analysis and quantitative analysis of the textile.

  9. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan A.

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in real-time. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors.

  10. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in realtime. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors

  11. Transmission spectra of teeth in the visible to near infrared

    NASA Astrophysics Data System (ADS)

    Herr, Steven L.; Harbour, John D.; Sherwood, Timothy S.; Wist, Abund O.

    1994-05-01

    Investigations of new transillumination techniques have created a need for detailed transmission studies of teeth and tissues. Recent results have shown that light imaging of extracted teeth can identify small (1 mm2 cross-section) caries in teeth by raster scanning using helium-neon laser light and a post collimated in-line detector. Preliminary frequency (wavelength) dependent transmission studies have been carried out from the visible to the near infrared spectral regions on the dentin of a slice of an extracted tooth 1.85 mm thick. These preliminary results show that in the region from 5,000 to 20,000 cm-1 the dentin of an extracted, healthy, human tooth has a transmission of between 2.5 and 5.5 percent, indicating that the total attenuation coefficient is between 16 and 19.5 cm-1.

  12. GNOSIS: an OH suppression unit for near-infrared spectrographs

    NASA Astrophysics Data System (ADS)

    Ellis, S. C.; Bland-Hawthorn, J.; Lawrence, J. S.; Bryant, J.; Haynes, R.; Horton, A.; Lee, S.; Leon-Saval, S.; Löhmannsröben, Hans-Gerd; Mladenoff, J.; O'Byrne, J.; Rambold, W.; Roth, M.; Trinh, C.

    2010-07-01

    GNOSIS is an OH suppression unit to be used in conjunction with existing spectrographs. The OH suppression is achieved using fibre Bragg gratings (FBGs), and will deliver the darkest near-infrared background of any ground-based instrument. Laboratory and on-sky tests demonstrate that FBGs can suppress OH lines by 30dB whilst maintaing > 90% throughput between the lines, resulting in a 4 mag decrease in the background. In the first implementation GNOSIS will feed IRIS2 on the AAT. It will consist of a seven element lenslet array, covering 1.4" on the sky, and will suppress the 103 brightest OH lines between 1.47 and 1.70 μm. Future upgrades will include J-band suppression and implementation on an 8m telescope.

  13. Visible and near infrared reflectances measured from laboratory ice clouds.

    PubMed

    Barkey, Brian; Liou, K N

    2008-05-01

    We present laboratory results of the 0.68 microm visible (VIS) and 1.617 microm near infrared (NIR) reflectances typically used for inferring optical depth and ice crystal size from satellite radiometers, from ice clouds generated in a temperature controlled column cloud chamber. Two types of ice crystals were produced in this experiment: small columns and dendrites with mean maximum dimensions of about 17 and 35 microm. Within experimental uncertainty, the measured reflectances from ice clouds at both wavelengths agree reasonably well with the theoretical results computed from the plane-parallel adding-doubling method for radiative transfer using the measured ice particle morphology. We demonstrate that laboratory scattering and reflectance data for thin ice clouds with optical depths less than 0.4 can be used for validation of the thin cirrus optical depth and ice crystal size that have been routinely retrieved from the satellite VIS-NIR two channel pair. PMID:18449323

  14. Low-cost near-infrared sensors for EVS

    NASA Astrophysics Data System (ADS)

    Tiana, Carlo L.

    2003-09-01

    The utility of Near-Infrared (NIR) sensors for Enhanced Vision System (EVS) applications has been identified and well documented. In particular, such sensors are well suited to detecting runway approach lighting, and often outperform the pilot's vision for this task. We present the results of field tests of very low cost NIR sensors, based on sensitive visible-light cameras, for this application; the cost/benefit tradeoffs of these sensors are so favorable that they may well form the core of a basic EVS system, or an effective enhancement to EVS systems based on other primary vision sensors. Useful processing techniques for imagery from these sensors, in the presence of cooperative sensors, or as a standalone system, are also presented.

  15. Near Infrared Fluorescent NanoGUMBOS for Biomedical Imaging

    PubMed Central

    Bwambok, David K.; El-Zahab, Bilal; Challa, Santhosh K.; Li, Min; Chandler, Lin; Baker, Gary A.; Warner, Isiah M.

    2009-01-01

    Herein, we report on near infrared (NIR) fluorescent nanoparticles generated from an emergent class of materials we refer to as a Group of Uniform Materials Based on Organic Salts (GUMBOS). GUMBOS are largely frozen ionic liquids, although the concept is more general and is also easily applied to solid ionic materials with melting points in excess of 100 °C. Nanoparticles based on GUMBOS (nanoGUMBOS) derived from a NIR fluorophore are prepared using a reprecipitation method and evaluated for in vivo fluorescence imaging. Due to their uniformity, single-step preparation, and composite nature, nanoGUMBOS help to resolve issues with dye leakage problems innate to alternate cellular stains and unlock a myriad of applications for these materials, highlighting exciting possibilities for multifunctional nanoGUMBOS. PMID:19928781

  16. Recent advances in fetal near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    D'Antona, Donato; Aldrich, Clive J.; O'Brien, Patrick; Lawrence, Sally; Delpy, David T.; Wyatt, John S.

    1997-01-01

    Fetal brain injury resulting from hypoxia and ischemia during labor remains an important cause of death and long- term disability. However, little is known about fetal brain oxygenation and hemodynamics. There are currently no satisfactory clinical techniques for fetal monitoring and there remains a need for a new method to assess brain oxygenation. Fetal near infrared spectroscopy (NIRS) is a new technique that allows noninvasive observation of changes in the cerebral concentrations of oxyhemoglobin and deoxyhemoglobin to be made during labor. A specially designed optical probe is inserted through the dilated cervix and placed against the fetal head. It is then possible to compare changes in NIRS data with other observations of fetal conditions, such as fetal heart rate and acid-base status.

  17. Fabric inspection by near-infrared machine vision.

    PubMed

    Millán, Maria S; Escofet, Jaume

    2004-07-01

    Fabrics that have superstructures of colored squares, bands, etc., superimposed upon the basic web structure can be advantageously analyzed by use of near-infrared (NIR) illumination and a conventional monochrome camera. The reduction in contrast of the superstructure signal in the NIR image facilitates inspection of the fabric's structure and defect segmentation. Underdetection and misdetection errors are noticeably reduced. This inspection takes advantage of the residual sensitivity of a monochrome camera, which can reach 1000 nm. The light source is an array of NIR LEDs emitting in a band to which the camera is still sensitive. NIR visual inspection can be performed by machines or by humans. In the latter case the observer looks at the NIR image of the fabric displayed on a TV monitor.

  18. Near-infrared transmittance pulse oximetry with laser diodes.

    PubMed

    Lopez Silva, Sonnia Maria; Dotor Castilla, Maria Luisa; Silveira Martin, Juan Pedro

    2003-07-01

    Pulse oximeters are widely used for noninvasive monitoring of oxygen saturation in arterial blood hemoglobin. We present a transmittance pulse oximetry system based on near-infrared (NIR) laser diodes (750 and 850 nm) for monitoring oxygen saturation of arterial blood hemoglobin. The pulse oximetry system is made up of the optical sensor, sensor electronics, and processing block. Also, we show experimental results obtained during the development of the whole NIR transmittance pulse oximetry system along with modifications in the sensor configuration, signal processing algorithm, and calibration procedure. Issues concerning wavelength selection and its implications for the improvement of the transmittance pulse oximetry technique are discussed. The results obtained demonstrate the proposed system's usefulness in monitoring a wide range of oxygen saturation levels.

  19. Biochemical and physiological basis of medical near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Joebsis-vander Vliet, Frans F.; Joebsis, Paul

    1999-10-01

    Near infrared spectroscopy (NIRS) can monitor both the redox status of Cytochrome c oxidase located in the mitochondria within the cell and the oxygenation of the blood in the tissue being monitored. Since the enzyme catalyzes more than 90% of oxygen utilization, it is the sink for the oxygen while the hemoglobin in the capillaries is the oxygen source. In order to evaluate the oxidative metabolic status of a tissue the optical data obtained from both molecules are commonly interpreted in the basis of test tube experiments with purified preparations. We are concerned that the validity of this practice may not have been tested sufficiently and raise four basic questions that have not yet been answered. Citing some examples of in vitro versus in vivo differences we conclude that more effort should be expended on the in vivo testing of the range of the signals, their natural variability, and the physiological and pathological meaning of their deviations from norm.

  20. High-resolution near-infrared spectroscopy of water dimer

    NASA Technical Reports Server (NTRS)

    Huang, Z. S.; Miller, R. E.

    1989-01-01

    High-resolution near-infrared spectra are reported for all of the O-H stretch vibrational bands of the water dimer. The four O-H vibrations are characterized as essentially independent proton-donor or proton-acceptor motions. In addition to the rotational and vibrational information contained in these spectra, details are obtained concerning the internal tunneling dynamics in both the ground and excited vibrational states. These results show that, for tunneling motions which involve the interchange of the proton donor and acceptor molecules, the associated frequencies decrease substantially due to vibrational excitation. The predissociation lifetimes for the various states of the dimer are determined from linewidth measurements. These results clearly show that the predissociation dynamics is strongly dependent on the tunneling states, as well as the Ka quantum number, indicating that the internal tunneling dynamics plays an important role in determining the dissociation rate in this complex.

  1. Venus Near-Infrared Spectra: SCIAMACHY-Observations and Modeling

    NASA Astrophysics Data System (ADS)

    Vasquez, Mayte; Schreier, Franz; Gimeno--Garcia, Sebastian; Gottwald, Manfred

    SCIAMACHY (Scanning Imaging Spectrometer for Atmospheric Chartography) onboard EN-VISAT successfully captured visible and near-infrared spectra of sunlight scattered and reflected from Venus atmosphere. Observations took place in March, when SCIAMACHY captured light mainly from the limb of Venus, and in June 2009, when a larger fraction of the planetary disk was illuminated representing a nadir viewing. Venus spectra were simulated using a line-by-line radiative transfer model, which also takes into account single scattering from atmospheric particles and molecules. Comparing SCIAMACHY's Venus observations with modeled spectra serves as a test for radiative transfer modeling of planetary atmospheres, an essential prereq-uisite for the search of living planets.

  2. Near infrared photodissociation spectra of the aniline +-argon ionic complexes

    NASA Astrophysics Data System (ADS)

    Pino, T.; Douin, S.; Boudin, N.; Bréchignac, Ph.

    2006-02-01

    The near infrared spectra of the ionic complexes aniline(NH 2) +-argon and aniline(ND 2) +-argon have been measured by laser photodissociation spectroscopy. The bands observed from 10 500 to 13 500 cm -1 have been assigned to the D1(A˜2A2)←D0(X˜2B1) electronic transition within the solvated chromophore. They are characterized by a long vibrational progression involving the 6a mode. On the basis of CASSCF calculations, a large change of geometry along this coordinate is found while the amino group remains in the ring plane. Therefore, a change of the conjugation of the ring rather than a charge transfer is inferred. This is thought to be the origin of the extent of the progression.

  3. Preliminary status of POLICAN: A near-infrared imaging polarimeter

    NASA Astrophysics Data System (ADS)

    Devaraj, R.; Luna, A.; Carrasco, L.; Mayya, Y. D.

    2015-10-01

    POLICAN is a near-infrared (J, H, K) imaging polarimeter developed for the Cananea near infrared camera (CANICA) at the 2.1m telescope of the Guillermo Haro Astrophysical Observatory (OAGH) located at Cananea, Sonora, México. The camera has a 1024 x 1024 HgCdTe detector (HAWAII array) with a plate scale of 0.32 arcsec/pixel providing a field of view of 5.5 x 5.5 arcmin. POLICAN is mounted externally to CANICA for narrow-field (f/12) linear polarimetric observations. It consists of a rotating super achromatic (1-2.7μm) half waveplate and a fixed wire-grid polarizer as the analyzer. The light is modulated by setting the half waveplate at different angles (0°, 22.5°, 45°, 67.5°) and linear combinations of the Stokes parameters (I, Q and U) are obtained. Image reduction and removal of instrumental polarization consist of dark noise subtraction, polarimetric flat fielding and background sky subtraction. Polarimetric calibration is performed by observing polarization standards available in the literature. The astrometry correction is performed by matching common stars with the Two Micron All Sky Survey. POLICAN's bright and limiting magnitudes are approximately 6th and 16th magnitude, which correspond to saturation and photon noise, respectively. POLICAN currently achieves a polarimetric accuracy about 3.0% and polarization angle uncertainties within 3°. Preliminary observations of star forming regions are being carried out in order to study their magnetic field properties.

  4. Optimal hemodynamic response model for functional near-infrared spectroscopy

    PubMed Central

    Kamran, Muhammad A.; Jeong, Myung Yung; Mannan, Malik M. N.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650–950 nm wavelengths. The cortical hemodynamic response (HR) differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF) is modeled by two Gamma functions with six unknown parameters (four of them to model the shape and other two to scale and baseline respectively). The HRF model is supposed to be a linear combination of HRF, baseline, and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown). An objective function is developed as a square of the residuals with constraints on 12 free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using 10 real and 15 simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis (i.e., t-value > tcritical and p-value < 0.05). PMID:26136668

  5. [Rapid determination of beet sugar content using near infrared spectroscopy].

    PubMed

    Yang, Yong; Ren, Jian; Zheng, Xi-Qun; Zhao, Li-Ying; Li, Mao-Mao

    2014-10-01

    In order to classify and set different prices on basis of difference of beet sugar content in the acquisition process and promote the development of beet sugar industry healthily, a fast, nondestructive, accurate method to detect sugar content of beet was determined by applying near infrared spectroscopy technology. Eight hundred twenty samples from 28 representative varieties of beet were collected as calibration set and 70 samples were chosen as prediction set. Then near infrared spectra of calibration set samples were collected by scanning, effective information was extracted from NIR spectroscopy, and the original spectroscopy data was optimized by data preprocessing methods appropriately. Then partial least square(PLS)regression was used to establish beet sugar quantitative prediction mathematical model. The performances of the models were evaluated by the root mean square of cross-validation (RMSECV), the coefficient of determination (R2) of the calibration model and the standard error of prediction (SEP), and the predicted results of these models were compared. Results show that the established mathematical model by using first derivative (FD) and standard normal variate transformation (SNV) coupled with partial least squares has good predictive ability. The R2 of calibration models of sugar content of beet is 0.908 3, and the RMSECV is 0.376 7. Using this model to forecast the prediction set including 70 samples, the correlation coefficient is 0.921 4 between predicted values and measured values, and the standard error of prediction (SEP) is 0.439, without significant difference (p > 0.05) between predicted values and measured values. These results demonstrated that NIRS can take advantage of simple, rapid, nondestructive and environmental detection method and could be applied to predict beet sugar content. This model owned high accuracy and can meet the precision need of determination of beet sugar content. This detection method could be used to classify

  6. Asteroid 951 Gaspra Near Infrared Mapping Spectrometer Radiance Data

    NASA Astrophysics Data System (ADS)

    Granahan, J. C., Jr.

    2015-12-01

    Five radiance spectra of asteroid 951 Gaspra have been archived in the Small Bodies Node of the NASA Planetary Data System [Granahan, 2014]. The radiance spectra were created from uncalibrated Galileo spacecraft Near Infrared Mapping Spectrometer files archived in the Imaging Node of the NASA Planetary Data System. The NASA Galileo spacecraft observed asteroid 951 Gaspra on October 29, 1991 with the Near Infrared Mapping Spectrometer (NIMS) at wavelengths ranging from 0.7 - 5.2 micrometers [Carlson et al., 1992]. The five radiance spectra consist of two 17, two 100, and one 329 spectral channel data sets. They record data that was acquired by NIMS at ranges between 27232.6 to 14723.8 kilometers from asteroid 951 Gaspra. The uncalibrated NIMS data were converted into radiance spectra using calibration coefficients obtained during the Galileo mission's first Earth encounter on December 8, 1990. The archived radiance spectral data is located at the URL (Universal Record Locator): http://sbn.psi.edu/pds/resource/gaspraspec.html and contains radiance, solar, incidence over flux, and data documentation. This archived data set contains a variety of spectral signatures. These signatures include absorptions near 1.0, 2.0, 2.8, 3.4, and 4.5 micrometers. The 1.0 and 2.0 micrometer features are indicators of olivine and pyroxene on the asteroid surface. The 2.8 micrometer feature has a shape similar to the combined spectra of multiple iron bearing phyllosilicates. The 3.4 micrometer feature is in the same location as absorptions created by a carbon-hydrogen bond. The 4.5 micrometer feature, present only in the 329 channel data set, corresponds in position to absorptions detected in sulfate minerals. Carlson, R. W., et al. (1992) Bull. of the A.A.S., 24, 932. Granahan, J. C. (2014), GO-A-NIMS-3-GASPRASPEC-V1.0, NASA Planetary Data System.

  7. Engineering adenylate cyclases regulated by near-infrared window light

    PubMed Central

    Ryu, Min-Hyung; Kang, In-Hye; Nelson, Mathew D.; Jensen, Tricia M.; Lyuksyutova, Anna I.; Siltberg-Liberles, Jessica; Raizen, David M.; Gomelsky, Mark

    2014-01-01

    Bacteriophytochromes sense light in the near-infrared window, the spectral region where absorption by mammalian tissues is minimal, and their chromophore, biliverdin IXα, is naturally present in animal cells. These properties make bacteriophytochromes particularly attractive for optogenetic applications. However, the lack of understanding of how light-induced conformational changes control output activities has hindered engineering of bacteriophytochrome-based optogenetic tools. Many bacteriophytochromes function as homodimeric enzymes, in which light-induced conformational changes are transferred via α-helical linkers to the rigid output domains. We hypothesized that heterologous output domains requiring homodimerization can be fused to the photosensory modules of bacteriophytochromes to generate light-activated fusions. Here, we tested this hypothesis by engineering adenylate cyclases regulated by light in the near-infrared spectral window using the photosensory module of the Rhodobacter sphaeroides bacteriophytochrome BphG1 and the adenylate cyclase domain from Nostoc sp. CyaB1. We engineered several light-activated fusion proteins that differed from each other by approximately one or two α-helical turns, suggesting that positioning of the output domains in the same phase of the helix is important for light-dependent activity. Extensive mutagenesis of one of these fusions resulted in an adenylate cyclase with a sixfold photodynamic range. Additional mutagenesis produced an enzyme with a more stable photoactivated state. When expressed in cholinergic neurons in Caenorhabditis elegans, the engineered adenylate cyclase affected worm behavior in a light-dependent manner. The insights derived from this study can be applied to the engineering of other homodimeric bacteriophytochromes, which will further expand the optogenetic toolset. PMID:24982160

  8. New quasars behind the Magellanic Clouds. Spectroscopic confirmation of near-infrared selected candidates

    NASA Astrophysics Data System (ADS)

    Ivanov, Valentin D.; Cioni, Maria-Rosa L.; Bekki, Kenji; de Grijs, Richard; Emerson, Jim; Gibson, Brad K.; Kamath, Devika; van Loon, Jacco Th.; Piatti, Andrés E.; For, Bi-Qing

    2016-04-01

    Context. Quasi-stellar objects (quasars) located behind nearby galaxies provide an excellent absolute reference system for astrometric studies, but they are difficult to identify because of fore- and background contamination. Deep wide-field, high angular resolution surveys spanning the entire area of nearby galaxies are needed to obtain a complete census of such quasars. Aims: We embarked on a program to expand the quasar reference system behind the Large and the Small Magellanic Clouds, the Magellanic Bridge, and the Magellanic Stream that connects the Clouds with the Milky Way. Methods: Hundreds of quasar candidates were selected based on their near-infrared colors and variability properties from the ongoing public ESO VISTA Magellanic Clouds survey. A subset of 49 objects was followed up with optical spectroscopy. Results: We confirmed the quasar nature of 37 objects (34 new identifications): four are low redshift objects, three are probably stars, and the remaining three lack prominent spectral features for a secure classification. The bona fide quasars, identified from their broad emisison lines, are located as follows: 10 behind the LMC, 13 behind the SMC, and 14 behind the Bridge. The quasars span a redshift range from z ~ 0.5 to z ~ 4.1. Conclusions: Upon completion the VMC survey is expected to yield a total of ~1500 quasars with Y< 19.32 mag, J< 19.09 mag, and Ks< 18.04 mag.

  9. [C II] emission in z ˜ 6 strongly lensed, star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Knudsen, Kirsten K.; Richard, Johan; Kneib, Jean-Paul; Jauzac, Mathilde; Clément, Benjamin; Drouart, Guillaume; Egami, Eiichi; Lindroos, Lukas

    2016-10-01

    The far-infrared fine-structure line [C II] at 1900.5 GHz is known to be one of the brightest cooling lines in local galaxies, and therefore it has been suggested to be an efficient tracer for star formation in very high redshift galaxies. However, recent results for galaxies at z > 6 have yielded numerous non-detections in star-forming galaxies, except for quasars and submillimetre galaxies. We report the results of ALMA observations of two lensed, star-forming galaxies at z = 6.029 and z = 6.703. The galaxy A383-5.1 (star formation rate [SFR] of 3.2 M⊙ yr-1 and magnification of μ = 11.4 ± 1.9) shows a line detection with L_[C II] = 8.9× 106 L⊙, making it the lowest L_[C II] detection at z > 6. For MS0451-H (SFR = 0.4 M⊙ yr-1 and μ = 100 ± 20) we provide an upper limit of L_[C II] < 3× 105 L⊙, which is 1 dex below the local SFR-L_[C II] relations. The results are consistent with predictions for low-metallicity galaxies at z > 6; however, other effects could also play a role in terms of decreasing L[CII]. The detection of A383-5.1 is encouraging and suggests that detections are possible, but much fainter than initially predicted.

  10. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  11. THE L-{sigma} RELATION OF LOCAL H II GALAXIES

    SciTech Connect

    Bordalo, V.; Telles, E. E-mail: etelles@on.br

    2011-07-01

    For the first time we present a new data set of emission line widths for 118 star-forming regions in H II galaxies (HIIGs). This homogeneous set is used to investigate the L-{sigma} relation in conjunction with optical spectrophotometric observations. We were able to classify their nebular emission line profiles due to our high-resolution spectra. Peculiarities in the line profiles such as sharp lines, wings, asymmetries, and in some cases more than one component in emission were verified. From a new independent homogeneous set of spectrophotometric data, we derived physical condition parameters and performed statistical principal component analysis. We have investigated the potential role of metallicity (O/H), H{beta} equivalent width (W{sub H{beta}}), and ionization ratio [O III]/[O II] to account for the observational scatter of the L-{sigma} relation. Our results indicate that the L-{sigma} relation for HIIGs is more sensitive to the evolution of the current starburst event (short-term evolution) and dated by W{sub H}{beta} or even the [O III]/[O II] ratio. The long-term evolution measured by O/H also plays a potential role in determining the luminosity of the current burst for a given velocity dispersion and age as previously suggested. Additionally, galaxies showing Gaussian line profiles present tighter correlations indicating that they are the best targets for the application of the parametric relations as an extragalactic cosmological distance indicator. Best fits for a restricted homogeneous sample of 45 HIIGs provide us with a set of new extragalactic distance indicators with an rms scatter compatible with observational errors of {delta}log L{sub H}{alpha} = 0.2 dex or 0.5 mag. Improvements may still come from future optimized observational programs to reduce the observational uncertainties on the predicted luminosities of HIIGs in order to achieve the precision required for the application of these relations as tests of cosmological models.

  12. A near-infrared magnetic aptasensor for Ochratoxin A based on near-infrared upconversion nanoparticles and magnetic nanoparticles.

    PubMed

    Dai, Shaoliang; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2016-09-01

    A multiplexed, sensitive and specific detection method is highly desirable for the simultaneous detection of several pathogenic bacteria and bio-toxins. In our previous work, multicolor upconversion nanoparticles (UCNPs) via doping with various rare-earth ions to obtain well-separated emission peaks by means of a solvothermal method were synthesized and were successfully applied as luminescence labels in the detection of three pathogenic bacteria. One of the basic achievements of our group has been to establish that the key to increasing the number of simultaneous detection components is the preparation of more UCNPs, the emission peaks of which can be distinguished from each other. According to this vision, NaYF4:Yb0.2, Tm0.02 UCNPs were obtained via a thermal-decomposition protocol, which has a main near-infrared (NIR) UC emission at 804nm under 980nm excitation. The emission peak at 804nm was well-separated from the emission peaks of UCNPs we have reported at 477nm, 542nm, and 660nm. It means both the excitation and the emission of NaYF4:Yb0.2, Tm0.02 UCNPs are located in the NIR spectral range (NIR-to-NIR UC emission), the so-called biological window. This result establishes the basis of achieving simultaneous detection of four components. To confirm the analytical performance of this NaYF4:Yb0.2, Tm0.02 UCNPs, a novel near-infrared magnetic aptasensor for the detection of Ochratoxin A (OTA) was developed using the OTA aptamer-conjugated near-infrared upconversion nanoparticles (apt-UCNPs) and the complementary oligonucleotide-modified magnetic nanoparticles (cDNA-MNPs). The apt-UCNPs and cDNA-MNPs were hybridized to form a poly-network structure of MNP-UCNP nanocomposites. When the target OTA was introduced, the aptamer combined with the priority target and the cDNA-MNPs were replaced. The proposed method achieved a linear range between 0.01 and 100ngmL(-1), with a detection limit as low as 0.005ngmL(-1). Then, we successfully applied this method to measure

  13. A near-infrared magnetic aptasensor for Ochratoxin A based on near-infrared upconversion nanoparticles and magnetic nanoparticles.

    PubMed

    Dai, Shaoliang; Wu, Shijia; Duan, Nuo; Wang, Zhouping

    2016-09-01

    A multiplexed, sensitive and specific detection method is highly desirable for the simultaneous detection of several pathogenic bacteria and bio-toxins. In our previous work, multicolor upconversion nanoparticles (UCNPs) via doping with various rare-earth ions to obtain well-separated emission peaks by means of a solvothermal method were synthesized and were successfully applied as luminescence labels in the detection of three pathogenic bacteria. One of the basic achievements of our group has been to establish that the key to increasing the number of simultaneous detection components is the preparation of more UCNPs, the emission peaks of which can be distinguished from each other. According to this vision, NaYF4:Yb0.2, Tm0.02 UCNPs were obtained via a thermal-decomposition protocol, which has a main near-infrared (NIR) UC emission at 804nm under 980nm excitation. The emission peak at 804nm was well-separated from the emission peaks of UCNPs we have reported at 477nm, 542nm, and 660nm. It means both the excitation and the emission of NaYF4:Yb0.2, Tm0.02 UCNPs are located in the NIR spectral range (NIR-to-NIR UC emission), the so-called biological window. This result establishes the basis of achieving simultaneous detection of four components. To confirm the analytical performance of this NaYF4:Yb0.2, Tm0.02 UCNPs, a novel near-infrared magnetic aptasensor for the detection of Ochratoxin A (OTA) was developed using the OTA aptamer-conjugated near-infrared upconversion nanoparticles (apt-UCNPs) and the complementary oligonucleotide-modified magnetic nanoparticles (cDNA-MNPs). The apt-UCNPs and cDNA-MNPs were hybridized to form a poly-network structure of MNP-UCNP nanocomposites. When the target OTA was introduced, the aptamer combined with the priority target and the cDNA-MNPs were replaced. The proposed method achieved a linear range between 0.01 and 100ngmL(-1), with a detection limit as low as 0.005ngmL(-1). Then, we successfully applied this method to measure

  14. A catalog of low surface brightness galaxies - List II

    NASA Technical Reports Server (NTRS)

    Schombert, James M.; Bothun, Gregory D.; Schneider, Stephen E.; Mcgaugh, Stacy S.

    1992-01-01

    A list of galaxies characterized by low surface brightness (LSB) is presented which facilitates the recognition of galaxies with brightnesses close to that of the sky. A total of 198 objects and 140 objects are listed in the primary and secondary catalogs respectively, and LSB galaxies are examined by means of H I redshift distributions. LSB disk galaxies are shown to have similar sizes and masses as the high-surface-brightness counterparts, and ellipticals and SOs are rarely encountered. Many LSB spirals have stellarlike nuclei, and most of the galaxies in the present catalog are late-type galaxies in the Sc, Sm, and Im classes. The LSB region of observational parameter space is shown to encompass a spectrum of types as full as that of the Hubble sequence. It is suggested that studies of LSB galaxies can provide important data regarding the formation and star-formation history of all galaxies.

  15. Saccharide substituted zinc phthalocyanines: optical properties, interaction with bovine serum albumin and near infrared fluorescence imaging for sentinel lymph nodes.

    PubMed

    Lu, Li; Lv, Feng; Cao, Bo; He, Xujun; Liu, Tianjun

    2014-01-03

    Saccharide-substituted zinc phthalocyanines, [2,9(10),16(17),23(24)-tetrakis((1-(β-D-glucose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato]zinc(II) and [2,9(10), 16(17),23(24)-tetrakis((1-(β-D-lactose-2-yl)-1H-1,2,3-triazol-4-yl)methoxy)phthalocyaninato] zinc(II), were evaluated as novel near infrared fluorescence agents. Their interaction with bovine serum albumin was investigated by fluorescence and circular dichroism spectroscopy and isothermal titration calorimetry. Near infrared imaging for sentinel lymph nodes in vivo was performed using nude mice as models. Results show that saccharide- substituted zinc phthalocyanines have favourable water solubility, good optical stability and high emission ability in the near infrared region. The interaction of lactose-substituted phthalocyanine with bovine serum albumin displays obvious differences to that of glucose- substituted phthalocyanine. Moreover, lactose-substituted phthalocyanine possesses obvious imaging effects for sentinel lymph nodes in vivo.

  16. Broad spectral domain fluorescence wavelength modulation of visible and near-infrared emissive polymersomes.

    PubMed

    Ghoroghchian, P Peter; Frail, Paul R; Susumu, Kimihiro; Park, Tae-Hong; Wu, Sophia P; Uyeda, H Tetsuo; Hammer, Daniel A; Therien, Michael J

    2005-11-01

    Incorporation of an extended family of multi[(porphinato)zinc(II)] (PZn)-based supermolecular fluorophores into the lamellar membranes of polymersomes (50 nm to 50 mum diameter polymer vesicles) gives rise to electrooptically diverse nano-to-micron (meso) scale soft materials. Studies that examine homogeneous suspensions of 100 nm diameter emissive polymersomes demonstrate fluorescence energy modulation over a broad spectral domain of the visible and near-infrared (600-900 nm). These polymersomal structures highlight that the nature of intermembranous polymer-to-fluorophore contacts depends on the position and identity of the porphyrins' phenyl ring substituents. Emissive polymersomes are shown to possess reduced spectral heterogeneity with respect to the established optical signatures of these PZn-based supermolecular fluorophores in solution; additionally, selection of fluorophore ancillary substituents predictably controls the nature of polymer-emitter noncovalent interactions to provide an important additional mechanism to further modulate the fluorescence band maxima of these meso-scale emissive vesicles.

  17. A Fast and Selective Near-Infrared Fluorescent Sensor for Multicolor Imaging of Biological Nitroxyl (HNO)

    PubMed Central

    2015-01-01

    The first near-infrared fluorescent turn-on sensor for the detection of nitroxyl (HNO), the one-electron reduced form of nitric oxide (NO), is reported. The new copper-based probe, CuDHX1, contains a dihydroxanthene (DHX) fluorophore and a cyclam derivative as a Cu(II) binding site. Upon reaction with HNO, CuDHX1 displays a five-fold fluorescence turn-on in cuvettes and is selective for HNO over thiols and reactive nitrogen and oxygen species. CuDHX1 can detect exogenously applied HNO in live mammalian cells and in conjunction with the zinc-specific, green-fluorescent sensor ZP1 can perform multicolor/multianalyte microscopic imaging. These studies reveal that HNO treatment elicits an increase in the concentration of intracellular mobile zinc. PMID:24564324

  18. Evaluation of redox-active iron sites in smectites using middle and near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Neumann, Anke; Petit, Sabine; Hofstetter, Thomas B.

    2011-05-01

    Redox processes of structural Fe in clay minerals play an important role in biogeochemical cycles and for the dynamics of contaminant transformation in soils and aquifers. Reactions of Fe(II)/Fe(III) in clay minerals depend on a variety of mineralogical and environmental factors, which make the assessment of Fe redox reactivity challenging. Here, we use middle and near infrared (IR) spectroscopy to identify reactive structural Fe(II) arrangements in four smectites that differ in total Fe content, octahedral cationic composition, location of the negative excess charge, and configuration of octahedral hydroxyl groups. Additionally, we investigated the mineral properties responsible for the reversibility of structural alterations during Fe reduction and re-oxidation. For Wyoming montmorillonite (SWy-2), a smectite of low structural Fe content (2.8 wt%), we identified octahedral AlFe(II)-OH as the only reactive Fe(II) species, while high structural Fe content (>12 wt%) was prerequisite for the formation of multiple Fe(II)-entities (dioctahedral AlFe(II)-OH, MgFe(II)-OH, Fe(II)Fe(II)-OH, and trioctahedral Fe(II)Fe(II)Fe(II)-OH) in iron-rich smectites Ölberg montmorillonite, and ferruginous smectite (SWa-1), as well as in synthetic nontronite. Depending on the overall cationic composition and the location of excess charge, different reactive Fe(II) species formed during Fe reduction in iron-rich smectites, including tetrahedral Fe(II) groups in synthetic nontronite. Trioctahedral Fe(II) domains were found in tetrahedrally charged ferruginous smectite and synthetic nontronite in their reduced state while these Fe(II) entities were absent in Ölberg montmorillonite, which exhibits an octahedral layer charge. Fe(III) reduction in iron-rich smectites was accompanied by intense dehydroxylation and structural rearrangements, which were only partially reversible through re-oxidation. Re-oxidation of Wyoming montmorillonite, in contrast, restored the original mineral structure

  19. Gratings and Random Reflectors for Near-Infrared PIN Diodes

    NASA Technical Reports Server (NTRS)

    Gunapala, Sarath; Bandara, Sumith; Liu, John; Ting, David

    2007-01-01

    Crossed diffraction gratings and random reflectors have been proposed as means to increase the quantum efficiencies of InGaAs/InP positive/intrinsic/ negative (PIN) diodes designed to operate as near-infrared photodetectors. The proposal is meant especially to apply to focal-plane imaging arrays of such photodetectors to be used for near-infrared imaging. A further increase in quantum efficiency near the short-wavelength limit of the near-infrared spectrum of such a photodetector array could be effected by removing the InP substrate of the array. The use of crossed diffraction gratings and random reflectors as optical devices for increasing the quantum efficiencies of quantum-well infrared photodetectors (QWIPs) was discussed in several prior NASA Tech Briefs articles. While the optical effects of crossed gratings and random reflectors as applied to PIN photodiodes would be similar to those of crossed gratings and random reflectors as applied to QWIPs, the physical mechanisms by which these optical effects would enhance efficiency differ between the PIN-photodiode and QWIP cases: In a QWIP, the multiple-quantum-well layers are typically oriented parallel to the focal plane and therefore perpendicular or nearly perpendicular to the direction of incidence of infrared light. By virtue of the applicable quantum selection rules, light polarized parallel to the focal plane (as normally incident light is) cannot excite charge carriers and, hence, cannot be detected. A pair of crossed gratings or a random reflector scatters normally or nearly normally incident light so that a significant portion of it attains a component of polarization normal to the focal plane and, hence, can excite charge carriers. A pair of crossed gratings or a random reflector on a PIN photodiode would also scatter light into directions away from the perpendicular to the focal plane. However, in this case, the reason for redirecting light away from the perpendicular is to increase the length of the

  20. Non-thermal DNA damage of cancer cells using near-infrared irradiation.

    PubMed

    Tanaka, Yohei; Tatewaki, Naoto; Nishida, Hiroshi; Eitsuka, Takahiro; Ikekawa, Nobuo; Nakayama, Jun

    2012-08-01

    Previously, we reported that near-infrared irradiation that simulates solar near-infrared irradiation with pre- and parallel-irradiational cooling can non-thermally induce cytocidal effects in cancer cells. To explore these effects, we assessed cell viability, DNA damage response pathways, and the percentage of mitotic cancer cells after near-infrared treatment. Further, we evaluated the anti-cancer effects of near-infrared irradiation compared with doxorubicin in xenografts in nude mice by measuring tumor volume and assessing protein phosphorylation by immunoblot analysis. The cell viability of A549 lung adenocarcinoma cells was significantly decreased after three rounds of near-infrared irradiation at 20 J/cm(2). Apoptotic cells were observed in near-infrared treated cells. Moreover, near-infrared treatment increased the phosphorylation of ataxia-telangiectasia mutated (ATM) at Ser(1981), H2AX at Ser(139), Chk1 at Ser(317), structural maintenance of chromosome (SMC) 1 at Ser(966), and p53 at Ser(15) in A549 cells compared with control. Notably, near-infrared treatment induced the formation of nucleic foci of γH2AX. The percentage of mitotic A549 cells, as measured by histone H3 phosphorylation, decreased significantly after three rounds of near-infrared irradiation at 20 J/cm(2). Both near-infrared and doxorubicin inhibited the tumor growth of MDA-MB435 melanoma cell xenografts in nude mice and increased the phosphorylation of p53 at Ser(15), Chk1 at Ser(317), SMC1 at Ser(966), and H2AX at Ser(139) compared with control mice. These results indicate that near-infrared irradiation can non-thermally induce cytocidal effects in cancer cells as a result of activation of the DNA damage response pathway. The near-infrared irradiation schedule used here reduces discomfort and side effects. Therefore, this strategy may have potential application in the treatment of cancer.

  1. Near-Infrared Imaging of the Central Regions of Metal-Poor Inner Spheroid Globular Clusters

    NASA Astrophysics Data System (ADS)

    Davidge, T. J.

    2001-06-01

    JHK images obtained with the Canada-France-Hawaii Telescope adaptive optics bonnette are used to investigate the near-infrared photometric properties of red giant branch (RGB) and horizontal-branch (HB) stars in eight metal-poor globular clusters with RGC<=2 kpc. The slope of the RGB on the (K, J-K) CMDs confirms the metal-poor nature of these clusters, four of which (NGC 6287, 6293, 6333, and 6355) are found to have metallicities that are comparable to M92. The luminosity functions of RGB stars in inner spheroid and outer halo clusters have similar slopes, although there is a tendency for core-collapsed clusters to have slightly flatter luminosity functions than noncollapsed clusters. The distribution of red HB stars on the (K, J-K) CMDs of inner spheroid clusters with [Fe/H]~-1.5 is very different from that of clusters with [Fe/H]~-2.2, suggesting that metallicity is the main parameter defining HB content among these objects. The RGB bump is detected in four of the inner spheroid clusters, and this feature is used to compute distances to these objects. Finally, the specific frequency of globular clusters in the inner Galaxy is discussed in the context of the early evolution of the bulge. Based on the ratio of metal-poor to metal-rich clusters in the inner Galaxy it is suggested that the metal-poor clusters formed during an early intense burst of star formation. It is also demonstrated that if the globular cluster formation efficiency for the inner Galaxy is similar to that measured in other spheroidal systems, then the main body of the bulge could have formed from gas that was chemically enriched in situ; hence, material from a separate pre-enriched reservoir, such as the disk or outer halo, may not be required to form the bulge.

  2. The near infrared camera for the Subaru Prime Focus Spectrograph

    NASA Astrophysics Data System (ADS)

    Smee, Stephen A.; Gunn, James E.; Golebiowski, Mirek; Barkhouser, Robert; Vivès, Sebastien; Pascal, Sandrine; Carr, Michael; Hope, Stephen C.; Loomis, Craig; Hart, Murdock; Sugai, Hajime; Tamura, Naoyuki; Shimono, Atsushi

    2014-08-01

    We present the detailed design of the near infrared camera for the SuMIRe (Subaru Measurement of Images and Redshifts) Prime Focus Spectrograph (PFS) being developed for the Subaru Telescope. The PFS spectrograph is designed to collect spectra from 2394 objects simultaneously, covering wavelengths that extend from 380 nm - 1.26 μm. The spectrograph is comprised of four identical spectrograph modules, with each module collecting roughly 600 spectra from a robotic fiber positioner at the telescope prime focus. Each spectrograph module will have two visible channels covering wavelength ranges 380 nm - 640 nm and 640 nm - 955 nm, and one near infrared (NIR) channel with a wavelength range 955 nm - 1.26 μm. Dispersed light in each channel is imaged by a 300 mm focal length, f/1.07, vacuum Schmidt camera onto a 4k x 4k, 15 µm pixel, detector format. For the NIR channel a HgCdTe substrate-removed Teledyne 1.7 μm cutoff device is used. In the visible channels, CCDs from Hamamatsu are used. These cameras are large, having a clear aperture of 300 mm at the entrance window, and a mass of ~ 250 kg. Like the two visible channel cameras, the NIR camera contains just four optical elements: a two-element refractive corrector, a Mangin mirror, and a field flattening lens. This simple design produces very good imaging performance considering the wide field and wavelength range, and it does so in large part due to the use of a Mangin mirror (a lens with a reflecting rear surface) for the Schmidt primary. In the case of the NIR camera, the rear reflecting surface is a dichroic, which reflects in-band wavelengths and transmits wavelengths beyond 1.26 μm. This, combined with a thermal rejection filter coating on the rear surface of the second corrector element, greatly reduces the out-of-band thermal radiation that reaches the detector. The camera optics and detector are packaged in a cryostat and cooled by two Stirling cycle cryocoolers. The first corrector element serves as the

  3. Dust evolution in the dwarf galaxy Holmberg II

    NASA Astrophysics Data System (ADS)

    Wiebe, D. S.; Khramtsova, M. S.; Egorov, O. V.; Lozinskaya, T. A.

    2014-05-01

    A detailed photometric study of star-forming regions (SFRs) in the galaxy Holmberg II has been carried out using the archival observational data from the far infrared to the ultraviolet obtained with the GALEX, Spitzer, and Herschel telescopes. Spectroscopic observations with the 6-m BTA telescope (Special Astrophysical Observatory of the Russian Academy of Sciences) are used to estimate the ages and metallicities of SFRs. The ages of SFRs have been correlated for the first time with their emission parameters in a wide spectral range and with the physical parameters determined by fitting the observed spectra. It is shown that the fluxes at 8 and 24 µm characterizing the emission from polycyclic aromatic hydrocarbons (PAHs) and hot dust grains decrease with age, but their ratio increases. This implies that the relative contribution from PAHs to the total infrared flux increases with age. It is hypothesized that the detected increase in the ratio of the fluxes at 8 and 24 µm is related to the increase in the relative PAH fraction due to the destruction of larger grains.

  4. Near-infrared orientation of Mozambique tilapia Oreochromis mossambicus.

    PubMed

    Shcherbakov, Denis; Knörzer, Alexandra; Hilbig, Reinhard; Haas, Ulrich; Blum, Martin

    2012-08-01

    Light plays a pivotal role in animal orientation. Aquatic animals face the problem that penetration of light in water is restricted through high attenuation which limits the use of visual cues. In pure water, blue and green light penetrates considerably deeper than red and infrared spectral components. Submicroscopic particles and coloured dissolved organic matter, however, may cause increased scattering and absorption of short-wave components of the solar spectrum, resulting in a relative increase of red and infrared illumination. Here we investigated the potential of near-infrared (NIR) light as a cue for swimming orientation of the African cichlid fish (Cichlidae) Oreochromis mossambicus. A high-throughput semi-automated video tracking assay was used to analyse innate behavioural NIR-sensitivity. Fish revealed a strong preference to swim in the direction of NIR light of a spectral range of 850-950nm at an irradiance similar to values typical of natural surface waters. Our study demonstrates the ability of teleost fish to sense NIR and use it for phototactic swimming orientation.

  5. NEAR-INFRARED LINEAR POLARIZATION OF ULTRACOOL DWARFS

    SciTech Connect

    Zapatero Osorio, M. R.; Bejar, V. J. S.; Rebolo, R.; Acosta-Pulido, J. A.; Manchado, A.; Pena Ramirez, K.; Caballero, J. A. E-mail: vbejar@iac.es E-mail: jaa@iac.es E-mail: karla@iac.es E-mail: caballero@cab.inta-csic.es

    2011-10-10

    We report on near-infrared J- and H-band linear polarimetric photometry of eight ultracool dwarfs (two late-M, five L0-L7.5, and one T2.5) with known evidence for photometric variability due to dust clouds, anomalous red infrared colors, or low-gravity atmospheres. The polarimetric data were acquired with the LIRIS instrument on the William Herschel Telescope. We also provide mid-infrared photometry in the interval 3.4-24 {mu}m for some targets obtained with Spitzer and WISE, which has allowed us to confirm the peculiar red colors of five sources in the sample. We can impose modest upper limits of 0.9% and 1.8% on the linear polarization degree for seven targets with a confidence of 99%. Only one source, 2MASS J02411151-0326587 (L0), appears to be strongly polarized (P {approx} 3%) in the J band with a significance level of P/{sigma}{sub P} {approx} 10. The likely origin of its linearly polarized light and rather red infrared colors may reside in a surrounding disk with an asymmetric distribution of grains. Given its proximity (66 {+-} 8 pc), this object becomes an excellent target for the direct detection of the disk.

  6. Integral field spectroscopy with the Gemini Near-Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Allington-Smith, Jeremy R.; Dubbeldam, Cornelis M.; Content, Robert; Dunlop, Colin J.; Robertson, David J.; Elias, Jay; Rodgers, Bernadette; Turner, James E.

    2004-09-01

    The Astronomical Instrumentation Group (AIG) of the University of Durham has recently completed an integral field unit (IFU) for use on the Gemini-South telescope with the Gemini Near-Infrared Spectrograph (GNIRS) built by the National Optical Astronomy Observatories (NOAO, USA). When the IFU is deployed remotely inside the instrument cryostat, GNIRS is converted into an integral field spectrograph with a field of 5 × 3 arcsec2 and spatial sampling of 0.15 × 0.15 arcsec2, optimised for 1-2.5μm but operable up to 5μm. We present summaries of the design and construction and results from laboratory testing. We also show results obtained at the telescope where a throughput of 90% was measured at 2.5μm, and show that this is consistent with predictions of a simple model where surface scattering is the dominant loss mechanism. The throughput data are well fit by the roughness measured in the laboratory. Finally, we show a few examples of astrophysical data from the commissioning run in April 2004.

  7. Constraining Type Ia Supernova Physics with Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sand, David; Valenti, Stefano; Howell, Andy; Graham, Melissa; Parrent, Jerod

    2014-08-01

    Despite their success as standardizable candles, relatively little is known about the exact progenitor(s) and explosion physics of type Ia supernovae -- a potential source of systematic uncertainty for future dark energy surveys, and a hole in our knowledge about stellar end-states. One promising route forward is the combination of dense optical time series and near-infrared (NIR) spectroscopic data sets. Recent work has suggested that the NIR can discern unburned carbon from the progenitor white dwarf more cleanly than in the optical, and its unique access to relatively unblended magnesium lines also probes the inner edge of carbon burning. Both measures provide a direct constraint for SN Ia explosion models, but only a handful of appropriate NIR spectroscopic time series exist. We propose to continue our campaign to roughly double the sample of SN Ia with such data (leveraging our access to a worldwide network of 1m imaging telescopes and twin robotic optical spectrographs) in order to begin to tackle our understanding of NIR spectral diagnostics and how they vary from supernova to supernova. During our 2014A time thus far, we have been intensely following the nearest SN Ia in a generation -- SN 2014J -- and have already submitted our initial results.

  8. Standardization of near infrared spectra measured on multi-instrument.

    PubMed

    Liu, Yan; Cai, Wensheng; Shao, Xueguang

    2014-07-11

    Calibration model transfer is essential for practical applications of near infrared (NIR) spectroscopy because the measurements of the spectra may be performed on different instruments and the difference between the instruments must be corrected. An approach for calibration transfer based on alternating trilinear decomposition (ATLD) algorithm is proposed in this work. From the three-way spectral matrix measured on different instruments, the relative intensity of concentration, spectrum and instrument is obtained using trilinear decomposition. Because the relative intensity of instrument is a reflection of the spectral difference between instruments, the spectra measured on different instruments can be standardized by a correction of the coefficients in the relative intensity. Two NIR datasets of corn and tobacco leaf samples measured with three instruments are used to test the performance of the method. The results show that, for both the datasets, the spectra measured on one instrument can be correctly predicted using the partial least squares (PLS) models built with the spectra measured on the other instruments.

  9. Broadband near-infrared tomography for breast cancer imaging

    NASA Astrophysics Data System (ADS)

    Wang, Jia

    Near-infrared (NIR) light provides potential for a new approach to non-invasive detection, diagnosis and clinical management of breast cancer. Using NIR spectroscopic imaging techniques, the physiological information about breast tissue composition can be quantitatively estimated, including hemoglobin, water and lipid concentrations, together with scattering properties. In this thesis work, strategies to improve the accuracy of NIR imaging have been explored experimentally and numerically. A novel Ti:Sapphire laser-based frequency domain tomography system was developed to achieve maximum spectral information, using intrinsic phase-locked detection of the signal propagation. The improvement in quantification through addition of more wavelengths was demonstrated in simulations and in tissue-phantom experiments. A hybrid NIR tomography system combining frequency domain and continuous wave spectroscopy approaches was implemented for imaging healthy subjects and women with malignant breast tumors. Adding measurements at wavelengths above 850nm with the continuous wave method significantly improved the accuracy of water and lipid estimation. When used in cancer imaging in vivo, the NIR contrast information is consistent with physiological and pathological values expected in tumor as seen by investigational studies with Magnetic Resonance Imaging (MRI) and pathology analysis.

  10. Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy

    PubMed Central

    Luo, Gan; Xu, Bing; Shi, Xinyuan; Li, Jianyu; Dai, Shengyun; Qiao, Yanjiang

    2015-01-01

    Chemical and physical quality attributes of herbal extract powders play an important role in the research and development of Chinese medicine preparations. The active pharmaceutical ingredients have a direct impact on the herbal extract's efficacy, while the physical properties of raw material affect the pharmaceutical manufacturing process and the final products' quality. In this study, tanshinone extract powders from Salvia miltiorrhiza which are widely used for the treatment of cardiovascular diseases in the clinic are taken as the research object. Both the chemical information and physical information of tanshinone extract powders are analyzed by near infrared (NIR) spectroscopy. The partial least squares (PLS) and least square support vector machine (LS-SVM) models are investigated to build the relationship between NIR spectra and reference values. PLS models performed well for the content of crytotanshinone, tanshinone IIA, the moisture, and average median particle size, while, for specific surface area and tapped density, the LS-SVM models performed better than the PLS models. Results demonstrated NIR to be a valid and fast process analytical technology tool to simultaneously determine multiple quality attributes of herbal extract powders and indicated that there existed some nonlinear relationship between NIR spectra and physical quality attributes. PMID:25866511

  11. Development of a new diffuse near-infrared food measuring

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Piao, Renguan

    2006-11-01

    Industries from agriculture to petrochemistry have found near infrared (NIR) spectroscopic analysis useful for quality control and quantitative analysis of materials and products. The general chemical, polymer chemistry, petrochemistry, agriculture, food and textile industries are currently using NIR spectroscopic methods for analysis. In this study, we developed a new sort NIR instrument for food measuring. The instrument consists of a light source, 12 filters to the prismatic part. The special part is that we use a mirror to get two beams of light. And two PbS detectors were used. One detector collected the radiation of one light beam directly and the value was set as the standard instead the standard white surface. Another light beam irradiate the sample surface, and the diffuse light was collected by another detector. The value of the two detectors was compared and the absorbency was computed. We tested the performance of the NIR instrument in determining the protein and fat content of milk powder. The calibration showed the accuracy of the instrument in practice.

  12. Near infrared light responsive hybrid nanoparticles for synergistic therapy.

    PubMed

    Liang, Yan; Gao, Wenxia; Peng, Xinyu; Deng, Xin; Sun, Changzhen; Wu, Huayue; He, Bin

    2016-09-01

    A near infrared (NIR) light responsive chromophore 7-(diethylamino)-4-(hydroxymethyl)-2H-chromen-2-one (DEACM) was synthesized and incorporated to β-cyclodextrins with cRGD functionalized poly(ethylene glycol), the amphiphiles were coordinated with Au nanorods or nanoparticles to load anticancer drug doxorubicin (DOX) for fabricating hybrid nanoparticles. The π-π stacking interaction between DEACM and DOX was formed in the hybrid nanoparticles, which contributed to the high drug loading content. The Au nanorods or nanoparticles enhanced the photosolvolysis of DEACM under the irradiation of NIR with 808 nm wavelength and triggered the accelerated drug release from the nanoparticles. The drug loaded hybrid nanoparticles with NIR irradiation exhibited efficient inhibition effect on the proliferation of 4T1 breast cancer cells in vitro. The in vivo anticancer activity study on breast cancer bearing mice revealed that the hybrid nanoparticles containing Au nanorods exhibited excellent anticancer activity under the irradiation of 808 nm wavelength NIR with 800 mW. PMID:27244691

  13. Near-infrared (NIR) up-conversion optogenetics.

    PubMed

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-01-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650-1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called 'imaging window'. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system. PMID:26552717

  14. Silicon photonic crystal thermal emitter at near-infrared wavelengths

    PubMed Central

    O’Regan, Bryan J.; Wang, Yue; Krauss, Thomas F.

    2015-01-01

    Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission. PMID:26293111

  15. Strategies for absolute calibration of near infrared tomographic tissue imaging.

    PubMed

    McBride, Troy O; Pogue, Brian W; Osterberg, Ulf L; Paulsen, Keith D

    2003-01-01

    Quantitative near infrared (NIR) imaging of tissue requires the use of a diffusion model-based reconstruction algorithm, which solves for the absorption and scattering coefficients of a tissue volume by matching transmission measurements of light to the predictive diffusion equation solution. Calibration problems as well as other practical considerations arise for an imaging system when using a model-based method for a real system. For example, systematic noise in the data acquisition hardware and source/detector fibers must be removed to prevent spurious results in the reconstructed image. Practical considerations for a NIR diffuse tomographic imaging system include: (1) calibration with a homogeneous phantom, (2) use of a homogenous fitting algorithm to arrive at an initial optical property estimate for image reconstruction of a heterogeneous medium, and (3) correction for fluctuations in source strength and initial phase offset during data acquisition. These practical considerations, which rely on an accurate homogeneous fitting algorithm are described. They have allowed demonstration of a prototype imaging system that has the ability to quantitatively reconstruct heterogeneous images of hemoglobin concentrations within a highly scattering medium with no a priori information.

  16. The application of near infrared spectroscopy in nutritional intervention studies

    PubMed Central

    Jackson, Philippa A.; Kennedy, David O.

    2013-01-01

    Functional near infrared spectroscopy (NIRS) is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF) and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials—in which the effects on CBF following administration of dietary components such as caffeine, polyphenols and omega-3 polyunsaturated fatty acids are assessed—have successfully demonstrated NIRS as a sensitive measure of change in hemodynamic response during cognitive tasks in both acute and chronic treatment intervention paradigms. The existent research in this area has been limited by the constraints of the technique itself however advancements in the measurement technology, paired with studies endeavoring increased sophistication in number and locations of channels over the head should render the use of NIRS in nutritional interventions particularly valuable in advancing our understanding of the effects of nutrients and dietary components on the brain. PMID:23964231

  17. Near-infrared free carrier absorption in heavily doped silicon

    SciTech Connect

    Baker-Finch, Simeon C.; McIntosh, Keith R.; Yan, Di; Fong, Kean Chern; Kho, Teng C.

    2014-08-14

    Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500 nm, and the range of dopant densities between ∼10{sup 18} and 3 × 10{sup 20} cm{sup −3}. Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis.

  18. Near-Infrared Optical Imaging Noninvasively Detects Acutely Damaged Muscle.

    PubMed

    Chrzanowski, Stephen M; Batra, Abhinandan; Lee-McMullen, Brittany; Vohra, Ravneet S; Forbes, Sean C; Jiang, Huabei; Vandenborne, Krista; Walter, Glenn A

    2016-10-01

    Muscle damage is currently assessed through methods such as muscle biopsy, serum biomarkers, functional testing, and imaging procedures, each with its own inherent limitations, and a pressing need for a safe, repeatable, inexpensive, and noninvasive modality to assess the state of muscle health remains. Our aim was to develop and assess near-infrared (NIR) optical imaging as a novel noninvasive method of detecting and quantifying muscle damage. An immobilization-reambulation model was used for inducing muscle damage and recovery in the lower hindlimbs in mice. Confirmation of muscle damage was obtained using in vivo indocyanine green-enhanced NIR optical imaging, magnetic resonance imaging, and ex vivo tissue analysis. The soleus of the immobilized-reambulated hindlimb was found to have a greater amount of muscle damage compared to that in the contralateral nonimmobilized limb, confirmed by in vivo indocyanine green-enhanced NIR optical imaging (3.86-fold increase in radiant efficiency), magnetic resonance imaging (1.41-fold increase in T2), and an ex vivo spectrophotometric assay of indocyanine green uptake (1.87-fold increase in normalized absorbance). Contrast-enhanced NIR optical imaging provides a sensitive, rapid, and noninvasive screening method that can be used for imaging and quantifying muscle damage and recovery in vivo. PMID:27565039

  19. Near-infrared light-responsive nanomaterials in cancer therapeutics.

    PubMed

    Shanmugam, Vijayakumar; Selvakumar, S; Yeh, Chen-Sheng

    2014-09-01

    Noninvasive techniques, such as breath tests (urea breath test), blood pressure measurements using a sphygmomanometer and electrocardiography, were employed by a physician to perform classical diagnosis. The use of state-of-the-art noninvasive therapies at the organ level in modern medicine has gradually become possible. However, cancer treatment demands spatially and temporally controlled noninvasive therapy at the cell level because nonspecific toxicity often causes complicated side effects. To increase survival in cancer patients further, combination therapy and combination drugs are explored which demand high specificity to avoid combined-drug side effects. We believe that high specificity could be obtained by implementing near-infrared (NIR) light-assisted nanoparticles in photothermal therapy, chemotherapy, and photodynamic therapy. To refine this therapy and subsequently achieve high efficiency, novel nanomaterials have been designed and modified either to enhance the uptake and drug delivery to the cancer site, or control treatment to administer therapy efficiently. These modifications and developments have been demonstrated to achieve spatial and temporal control when conducting an in vivo xenograft, because the NIR light penetrated effectively the biological tissue. The nanoplatforms discussed in this review are grouped under the following subheadings: Au nanorods (NRs), Au nanoshells, other Au-related nanomaterials, graphene oxide, upconversion nanoparticles, and other related materials (including materials such as CuS, Fe3O4-related systems, and carbon nanotubes (CNTs)).

  20. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy.

    PubMed

    Pociask, Elżbieta; Jaworek-Korjakowska, Joanna; Malinowski, Krzysztof Piotr; Roleder, Tomasz; Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects. PMID:27610191

  1. A novel storage method for near infrared spectroscopy chemometric models.

    PubMed

    Zhang, Zhi-Min; Chen, Shan; Liang, Yi-Zeng

    2010-06-01

    Chemometric Modeling Markup Language (CMML) is developed by us for containing chemometrics models within one document through converting binary data into strings by base64 encode/decode algorithms to solve the interoperability issue in sharing chemometrics models. It provides a base functionality for storage of sampling, variable selection, pretreating, outlier and modeling parameters and data. With the help of base64 algorithm, the usability of CMML is in equilibrium with size by transforming the binary data into base64 encoded string. Due to the advantages of Extensible Markup Language (XML), models stored in CMML can be easily reused in various other software and programming languages as long as the programming language has XML parsing library. One can also use the XML Path Language (XPath) query language to select desired data from the CMML file effectively. The application of this language in near infrared spectroscopy model storage is implemented as a class in C++ language and available as open source software (http://code.google.com/p/cmml), and the implementations in other languages, such as MATLAB and R are in progress. PMID:20493291

  2. 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.

  3. Retinal safety of near-infrared lasers in cataract surgery

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Sramek, Christopher; Paulus, Yannis M.; Lavinsky, Daniel; Schuele, Georg; Anderson, Dan; Dewey, David; Palanker, Daniel

    2012-09-01

    Femtosecond lasers have added unprecedented precision and reproducibility to cataract surgery. However, retinal safety limits for the near-infrared lasers employed in surgery are not well quantified. We determined retinal injury thresholds for scanning patterns while considering the effects of reduced blood perfusion from rising intraocular pressure and retinal protection from light scattering on bubbles and tissue fragments produced by laser cutting. We measured retinal damage thresholds of a stationary, 1030-nm, continuous-wave laser with 2.6-mm retinal spot size for 10- and 100-s exposures in rabbits to be 1.35 W (1.26 to 1.42) and 0.78 W (0.73 to 0.83), respectively, and 1.08 W (0.96 to 1.11) and 0.36 W (0.33 to 0.41) when retinal perfusion is blocked. These thresholds were input into a computational model of ocular heating to calculate damage threshold temperatures. By requiring the tissue temperature to remain below the damage threshold temperatures determined in stationary beam experiments, one can calculate conservative damage thresholds for cataract surgery patterns. Light scattering on microbubbles and tissue fragments decreased the transmitted power by 88% within a 12 deg angle, adding a significant margin for retinal safety. These results can be used for assessment of the maximum permissible exposure during laser cataract surgery under various assumptions of blood perfusion, treatment duration, and scanning patterns.

  4. Textile integrated sensors and actuators for near-infrared spectroscopy.

    PubMed

    Zysset, Christoph; Nasseri, Nassim; Büthe, Lars; Münzenrieder, Niko; Kinkeldei, Thomas; Petti, Luisa; Kleiser, Stefan; Salvatore, Giovanni A; Wolf, Martin; Tröster, Gerhard

    2013-02-11

    Being the closest layer to our body, textiles provide an ideal platform for integrating sensors and actuators to monitor physiological signals. We used a woven textile to integrate photodiodes and light emitting diodes. LEDs and photodiodes enable near-infrared spectroscopy (NIRS) systems to monitor arterial oxygen saturation and oxygenated and deoxygenated hemoglobin in human tissue. Photodiodes and LEDs are mounted on flexible plastic strips with widths of 4 mm and 2 mm, respectively. The strips are woven during the textile fabrication process in weft direction and interconnected with copper wires with a diameter of 71 μm in warp direction. The sensor textile is applied to measure the pulse waves in the fingertip and the changes in oxygenated and deoxygenated hemoglobin during a venous occlusion at the calf. The system has a signal-to-noise ratio of more than 70 dB and a system drift of 0.37% ± 0.48%. The presented work demonstrates the feasibility of integrating photodiodes and LEDs into woven textiles, a step towards wearable health monitoring devices.

  5. Near-Infrared Photobiomodulation in Retinal Injury and Disease.

    PubMed

    Eells, Janis T; Gopalakrishnan, Sandeep; Valter, Krisztina

    2016-01-01

    Evidence is growing that exposure of tissue to low energy photon irradiation in the far-red (FR) to near-infrared (NIR) range of the spectrum, collectively termed "photobiomodulation" (PBM) can restore the function of damaged mitochondria, upregulate the production of cytoprotective factors and prevent apoptotic cell death. PBM has been applied clinically in the treatment of soft tissue injuries and acceleration of wound healing for more than 40 years. Recent studies have demonstrated that FR/NIR photons penetrate diseased tissues including the retina. The therapeutic effects of PBM have been hypothesized to result from intracellular signaling pathways triggered when FR/NIR photons are absorbed by the mitochondrial photoacceptor molecule, cytochrome c oxidase, culminating in improved mitochondrial energy metabolism, increased cytoprotective factor production and cell survival. Investigations in rodent models of methanol-induced ocular toxicity, light damage, retinitis pigmentosa and age-related macular degeneration have demonstrated the PBM attenuates photoreceptor cell death, protects retinal function and exerts anti-inflammatory actions.

  6. Dynamic causal modelling for functional near-infrared spectroscopy

    PubMed Central

    Tak, S.; Kempny, A.M.; Friston, K.J.; Leff, A.P.; Penny, W.D.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging technique for measuring changes in cerebral hemoglobin concentration via optical absorption changes. Although there is great interest in using fNIRS to study brain connectivity, current methods are unable to infer the directionality of neuronal connections. In this paper, we apply Dynamic Causal Modelling (DCM) to fNIRS data. Specifically, we present a generative model of how observed fNIRS data are caused by interactions among hidden neuronal states. Inversion of this generative model, using an established Bayesian framework (variational Laplace), then enables inference about changes in directed connectivity at the neuronal level. Using experimental data acquired during motor imagery and motor execution tasks, we show that directed (i.e., effective) connectivity from the supplementary motor area to the primary motor cortex is negatively modulated by motor imagery, and this suppressive influence causes reduced activity in the primary motor cortex during motor imagery. These results are consistent with findings of previous functional magnetic resonance imaging (fMRI) studies, suggesting that the proposed method enables one to infer directed interactions in the brain mediated by neuronal dynamics from measurements of optical density changes. PMID:25724757

  7. Noncontact tissue oxygenation measurement using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Niwayama, Masatsugu; Murata, Hideaki; Shinohara, Shigenobu

    2006-07-01

    Here, we present a noncontact tissue oxygenation monitor that uses near-infrared spectroscopy (NIRS). We examined changes in sensitivity of tissue oxygenation measurement due to changes in the distance between the optical probe and the skin surface using a Monte Carlo simulation and in vivo tests. We also examined the effects of skin and fat layer thickness. Photon migration was analyzed in a model consisting of the skin, fat, and muscle layers. The relationship between measurement sensitivity and the probe-tissue distance was obtained from the results of the simulation and was used for correction of measurements. A noncontact tissue oximeter was used to perform the in vivo tests and measure oxygen consumption of the forearm muscle. The value of corrected oxygen consumption was 0.12±0.03ml/(100gmin), which is consistent with previously reported values obtained using contact NIRS measurement and magnetic resonance spectroscopy. Quantitative measurement of oxygenation using noncontact NIRS is potentially useful for novel applications such as quantification of inflammation.

  8. Sensitivity analysis of near-infrared functional lymphatic imaging

    NASA Astrophysics Data System (ADS)

    Weiler, Michael; Kassis, Timothy; Dixon, J. Brandon

    2012-06-01

    Near-infrared imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, yet the imaging capabilities of this approach have yet to be quantitatively characterized. We seek to quantify its capabilities as a diagnostic tool for lymphatic disease. Imaging is performed in a tissue phantom for sensitivity analysis and in hairless rats for in vivo testing. To demonstrate the efficacy of this imaging approach to quantifying immediate functional changes in lymphatics, we investigate the effects of a topically applied nitric oxide (NO) donor glyceryl trinitrate ointment. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being 150 μg/mL ICG and 60 g/L albumin. ICG fluorescence can be detected at a concentration of 150 μg/mL as deep as 6 mm with our system, but spatial resolution deteriorates below 3 mm, skewing measurements of vessel geometry. NO treatment slows lymphatic transport, which is reflected in increased transport time, reduced packet frequency, reduced packet velocity, and reduced effective contraction length. NIR imaging may be an alternative to invasive procedures measuring lymphatic function in vivo in real time.

  9. Motion in Jupiter's Atmospheric Vortices (Near-infrared filters)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two frame 'movie' of a pair of vortices in Jupiter's southern hemisphere. The two frames are separated by ten hours. The right oval is rotating counterclockwise, like other anticyclonic bright vortices in Jupiter's atmosphere. The left vortex is a cyclonic (clockwise) vortex. The differences between them (their brightness, their symmetry, and their behavior) are clues to how Jupiter's atmosphere works. The frames span about fifteen degrees in latitude and longitude and are centered at 141 degrees west longitude and 36 degrees south planetocentric latitude. Both vortices are about 3500 kilometers in diameter in the north-south direction.

    The images were taken in near infrared light at 756 nanometers and show clouds that are at a pressure level of about 1 bar in Jupiter's atmosphere. North is at the top. The smallest resolved features are tens of kilometers in size. These images were taken on May 7, 1997, at a range of 1.5 million kilometers by the Solid State Imaging system on NASA's Galileo spacecraft.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  10. Near-infrared plasmonics with transparent conducting oxides (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kim, Jongbum; Kinsey, Nathaniel; DeVault, Clayton; Dutta, Aveek; Ferrera, Marcello; Shalaev, Vladimir; Boltasseva, Alexandra

    2016-04-01

    As a result of the significant attention in searching for alternative plasmonic materials for real-life nanophotonic devices, transparent conducting oxides (TCOs) have been proposed as promising constituent building blocks for telecommunication wavelengths. They are eminently practical materials because they are CMOS-compatible, can be grown on many different types of substrates, patterned by standard fabrication procedures, and integrated with many other standard technologies. Due to the ability of TCO nanostructures to support strong plasmonic resonance in the near infrared (NIR), metasurface devices, such as a quarter wave plate, have been demonstrated whose properties can be easily adjustable with post processing such as thermal annealing. Additionally, TCOs can be used as epsilon near zero (ENZ) materials in the NIR. From our recent study of the behavior of nanoantennae sitting upon a TCO substrate, we found that TCOs serve as an optical insulating media due to the high impedance of TCOs at the ENZ frequency, enabling emission shaping. Finally, the optical properties of TCOs can be varied by optical or electrical means. Current research is focused on studying the ultrafast carrier dynamics in doped zinc oxide films using pump-probe spectroscopy. We have shown that aluminum doped zinc oxide films can achieve a 40% change in reflection with ultrafast dynamics (<1ps) under a small fluence of 3mJ/cm2. Consequently, TCOs are shown to be extremely flexible materials, enabling fascinating physics and unique devices for applications in the NIR regime.

  11. Near Infrared Spectroscopic Evaluation Of Water In Hyaline Cartilage

    PubMed Central

    Padalkar, MV; Spencer, RG; Pleshko, N

    2013-01-01

    In diseased conditions of cartilage such as osteoarthritis, there is typically an increase in water content from the average normal of 60–85% to greater than 90%. As cartilage has very little capability for self-repair, methods of early detection of degeneration are required, and assessment of water could prove to be a useful diagnostic method. Current assessment methods are either destructive, time consuming or have limited sensitivity. Here, we investigated the hypotheses that non-destructive near infrared spectroscopy (NIRS) of articular cartilage can be used to differentiate between free and bound water, and to quantitatively assess water content. The absorbances centered at 5200 cm−1 and 6890 cm−1 were attributed to a combination of free and bound water, and to free water only, respectively. The integrated areas of both absorbance bands were found to correlate linearly with the absolute water content (R=0.87 and R= 0.86) and with percent water content (R=0.97 and R=0.96) of the tissue. Partial least square models were also successfully developed and were used to predict water content, and percent free water. These data demonstrate that NIRS can be utilized to quantitatively determine water content in articular cartilage, and may aid in early detection of degenerative tissue changes in a laboratory setting, and with additional validations, possibly in a clinical setting. PMID:23824216

  12. Graphene surface plasmons at the near-infrared optical regime

    PubMed Central

    Zhang, Qiming; Li, Xiangping; Hossain, Md Muntasir; Xue, Yunzhou; Zhang, Jie; Song, Jingchao; Liu, Jingying; Turner, Mark D.; Fan, Shanhui; Bao, Qiaoliang; Gu, Min

    2014-01-01

    Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back electrical gating and chemical doping methods cannot facilitate the demonstration of graphene SPs at the near-infrared (NIR) window because of the limited shift of the Fermi level. Here, we present the evidence for the existence of graphene SPs on a tapered graphene-silicon waveguide tip at a NIR wavelength, employing a surface carrier transfer method with molybdenum trioxides. The coupling between the graphene surface plasmons and the guiding mode in silicon waveguides allows for the observation of the concentrated field of the SPs in the tip by near-field scanning optical microscopy. Thus the hot spot from the concentrated SPs in the graphene layer can be used as a key experimental signature of graphene SPs. The NIR graphene SPs opens a new perspective for optical communications, optical sensing and imaging, and optical data storage with extreme spatial confinement, broad bandwidth and high tunability. PMID:25297570

  13. Silicon photonic crystal thermal emitter at near-infrared wavelengths.

    PubMed

    O'Regan, Bryan J; Wang, Yue; Krauss, Thomas F

    2015-08-21

    Controlling thermal emission with resonant photonic nanostructures has recently attracted much attention. Most of the work has concentrated on the mid-infrared wavelength range and/or was based on metallic nanostructures. Here, we demonstrate the experimental operation of a resonant thermal emitter operating in the near-infrared (≈1.5 μm) wavelength range. The emitter is based on a doped silicon photonic crystal consisting of a two dimensional square array of holes and using silicon-on-insulator technology with a device-layer thickness of 220 nm. The device is resistively heated by passing current through the photonic crystal membrane. At a temperature of ≈1100 K, we observe relatively sharp emission peaks with a Q factor around 18. A support structure system is implemented in order to achieve a large area suspended photonic crystal thermal emitter and electrical injection. The device demonstrates that weak absorption together with photonic resonances can be used as a wavelength-selection mechanism for thermal emitters, both for the enhancement and the suppression of emission.

  14. LED-based near infrared sensor for cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Bogomolov, Andrey; Ageev, Vladimir; Zabarylo, Urszula; Usenov, Iskander; Schulte, Franziska; Kirsanov, Dmitry; Belikova, Valeria; Minet, Olaf; Feliksberger, E.; Meshkovsky, I.; Artyushenko, Viacheslav

    2016-03-01

    Optical spectroscopic technologies are increasingly used for cancer diagnostics. Feasibility of differentiation between malignant and healthy samples of human kidney using Fluorescence, Raman, MIR and NIR spectroscopy has been recently reported . In the present work, a simplification of NIR spectroscopy method has been studied. Traditional high-resolution NIR spectrometry was replaced by an optical sensor based on a set of light-emitting diodes at selected wavelengths as light sources and a photodiode. Two prototypes of the sensor have been developed and tested using 14 in-vitro samples of seven kidney tumor patients. Statistical evaluation of results using principal component analysis and partial least-squares discriminant analysis has been performed. Despite only partial discrimination between tumor and healthy tissue achieved by the presented new technique, the results evidence benefits of LED-based near-infrared sensing used for oncological diagnostics. Publisher's Note: This paper, originally published on 4 March, 2016, was replaced with a corrected/revised version on 7 April, 2016. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  15. Novel near infrared sensors for hybrid BCI applications

    NASA Astrophysics Data System (ADS)

    Almajidy, Rand K.; Le, Khang S.; Hofmann, Ulrich G.

    2015-07-01

    This study's goal is to develop a low cost, portable, accurate and comfortable NIRS module that can be used simultaneously with EEG in a dual modality system for brain computer interface (BCI). The sensing modules consist of electroencephalography (EEG) electrodes (at the positions Fp1, Fpz and Fp2 in the international 10-20 system) with eight custom made functional near infrared spectroscopy (fNIRS) channels, positioned on the prefrontal cortex area with two extra channels to measure and eliminate extra-cranial oxygenation. The NIRS sensors were designed to guarantee good sensor-skin contact, without causing subject discomfort, using springs to press them to the skin instead of pressing them by cap fixture. Two open source software packages were modified to carry out dual modality hybrid BCI experiments. The experimental paradigm consisted of a mental task (arithmetic task or text reading) and a resting period. Both oxygenated hemoglobin concentration changes (HbO), and EEG signals showed an increase during the mental task, but the onset, period and amount of that increase depends on each modality's characteristics. The subject's degree of attention played an important role especially during online sessions. The sensors can be easily used to acquire brain signals from different cerebral cortex parts. The system serves as a simple technological test bed and will be used for stroke patient rehabilitation purposes.

  16. Simulation and measurement of transcranial near infrared light penetration

    NASA Astrophysics Data System (ADS)

    Yue, Lan; Monge, Manuel; Ozgur, Mehmet H.; Murphy, Kevin; Louie, Stan; Miller, Carol A.; Emami, Azita; Humayun, Mark S.

    2015-03-01

    We are studying the transmission of LED array-emitted near-infrared (NIR) light through human tissues. Herein, we simulated and measured transcranial NIR penetration in highly scattering human head tissues. Using finite element analysis, we simulated photon diffusion in a multilayered 3D human head model that consists of scalp, skull, cerebral spinal fluid, gray matter and white matter. The optical properties of each layer, namely scattering and absorption coefficient, correspond to the 850 nm NIR light. The geometry of the model is minimally modified from the IEEE standard and the multiple LED emitters in an array were evenly distributed on the scalp. Our results show that photon distribution produced by the array exhibits little variation at similar brain depth, suggesting that due to strong scattering effects of the tissues, discrete spatial arrangements of LED emitters in an array has the potential to create a quasi-radially symmetrical illumination field. Measurements on cadaveric human head tissues excised from occipital, parietal, frontal and temporal regions show that illumination with an 850 nm LED emitter rendered a photon flux that closely follows simulation results. In addition, prolonged illumination of LED emitted NIR showed minimal thermal effects on the brain.

  17. Near-infrared (NIR) up-conversion optogenetics

    PubMed Central

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-01-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650–1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called ‘imaging window’. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system. PMID:26552717

  18. Fluorescence lifetime imaging with near-infrared dyes

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Shcheslavskiy, Vladislav

    2013-02-01

    Near-infrared (NIR) dyes are used as fluorescence markers in small-animal imaging and in diffuse optical tomography of the human brain. In these applications it is important to know whether the dyes bind to proteins or other tissue constituents, and whether their fluorescence lifetimes depend on the targets they are bound to. Unfortunately, neither the lasers nor the detectors of commonly used confocal and multiphoton laser scanning microscopes allow for excitation and detection of NIR fluorescence. We therefore upgraded existing confocal TCSPC FLIM systems with NIR lasers and NIR sensitive detectors. In multiphoton systems we used the Ti:Sa laser as a one-photon excitation source in combination with an NIR-sensitive detector in the confocal beam path. We tested a number of NIR dyes in biological tissue. Some of them showed clear lifetime changes depending on the tissue structures they are bound to. We therefore believe that NIR FLIM can deliver supplementary information on the tissue constitution and on local biochemical parameters.

  19. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    PubMed Central

    Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects. PMID:27610191

  20. Bundled-Optode Method in Functional Near-Infrared Spectroscopy

    PubMed Central

    Nguyen, Hoang-Dung; Hong, Keum-Shik; Shin, Yong-Il

    2016-01-01

    In this paper, a theory for detection of the absolute concentrations of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) from hemodynamic responses using a bundled-optode configuration in functional near-infrared spectroscopy (fNIRS) is proposed. The proposed method is then applied to the identification of two fingers (i.e., little and thumb) during their flexion and extension. This experiment involves a continuous-wave-type dual-wavelength (760 and 830 nm) fNIRS and five healthy male subjects. The active brain locations of two finger movements are identified based on the analysis of the t- and p-values of the averaged HbOs, which are quite distinctive. Our experimental results, furthermore, revealed that the hemodynamic responses of two-finger movements are different: The mean, peak, and time-to-peak of little finger movements are higher than those of thumb movements. It is noteworthy that the developed method can be extended to 3-dimensional fNIRS imaging. PMID:27788178

  1. Predicting beef tenderness using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Jeyamkondan, Subbiah; Kranzler, Glenn A.; Morgan, Brad J.; Rust, Sarah

    2004-03-01

    A near-infrared spectral reflectance system was developed and tested online to predict 14-day aged, cooked beef tenderness. A contact probe with a built-in tungsten-halogen light source supplied broadband light to the ribeye surface. Fiberoptics in the probe transmitted reflected light to a spectrometer with a spectral range of 400-2500 nm. In the first phase, steak samples (n=292) were brought from packing plants to the lab and scanned with the spectrometer. After scanning, samples were vacuum-packaged and aged for 14 days. They were then cooked in an impingement oven to an internal temperature of 70°C. Slice-shear force values were recorded for tenderness reference. In phase two, the spectrometer was modified for packing plant conditions. Spectral scans were obtained on-line on ribbed carcasses (n=276). A partial least square regression model was developed to predict tenderness scores from spectral reflectance. In phase three, the developed model was validated by scanning carcasses (n=200) on-line. The predicted shear-force values and samples were sent to the U.S. Meat Animal Research Center for third-party validation. At up to 70% certification levels, the system was able to successfully sort tough from tender carcasses.

  2. Near-Infrared Grating Spectrometer for Mobile Phone Applications.

    PubMed

    Pügner, Tino; Knobbe, Jens; Grüger, Heinrich

    2016-05-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications.

  3. Near-infrared oxygen airglow from the Venus nightside

    NASA Technical Reports Server (NTRS)

    Crisp, D.; Meadows, V. S.; Allen, D. A.; Bezard, B.; Debergh, C.; Maillard, J.-P.

    1992-01-01

    Groundbased imaging and spectroscopic observations of Venus reveal intense near-infrared oxygen airglow emission from the upper atmosphere and provide new constraints on the oxygen photochemistry and dynamics near the mesopause (approximately 100 km). Atomic oxygen is produced by the Photolysis of CO2 on the dayside of Venus. These atoms are transported by the general circulation, and eventually recombine to form molecular oxygen. Because this recombination reaction is exothermic, many of these molecules are created in an excited state known as O2(delta-1). The airglow is produced as these molecules emit a photon and return to their ground state. New imaging and spectroscopic observations acquired during the summer and fall of 1991 show unexpected spatial and temporal variations in the O2(delta-1) airglow. The implications of these observations for the composition and general circulation of the upper venusian atmosphere are not yet understood but they provide important new constraints on comprehensive dynamical and chemical models of the upper mesosphere and lower thermosphere of Venus.

  4. Examining the Phonological Neighborhood Density Effect Using Near Infrared Spectroscopy

    PubMed Central

    Chen, Hsin-Chin; Vaid, Jyotsna; Boas, David A.; Bortfeld, Heather

    2010-01-01

    Phonological density refers to the number of words that can be generated by replacing a phoneme in a target word with another phoneme in the same position. Although the precise nature of the phonological neighborhood density effect is not firmly established, many behavioral psycholinguistic studies have shown that visual recognition of individual words is influenced by the number and type of neighbors the words have. This study explored neurobehavioral correlates of phonological neighborhood density in skilled readers of English using near infrared spectroscopy. On the basis of a lexical decision task, our findings showed that words with many phonological neighbors (e.g., FRUIT) were recognized more slowly than words with few phonological neighbors (e.g., PROOF), and that words with many neighbors elicited significantly greater changes in blood oxygenation in the left than in the right hemisphere of the brain, specifically in the areas BA 22/39/40. In previous studies these brain areas have been implicated in fine-grained phonological processing in readers of English. The present findings provide the first demonstration that areas BA 22/39/40 are also sensitive to phonological density effects. PMID:20690126

  5. Constraining Type Ia Supernova Physics with Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sand, David; Valenti, Stefano; Howell, Andy; Graham, Melissa; Parrent, Jerod

    2014-02-01

    Despite their success as standardizable candles, relatively little is known about the exact progenitor(s) and explosion physics of type Ia supernovae -- a potential source of systematic uncertainty for future dark energy surveys, and a hole in our knowledge about stellar end-states. One promising route forward is the combination of dense optical time series and near-infrared (NIR) spectroscopic data sets. Recent work has suggested that the NIR can discern unburned carbon from the progenitor white dwarf more cleanly than in the optical, and its unique access to relatively unblended magnesium lines also probes the inner edge of carbon burning. Both measures provide a direct constraint for SN Ia explosion models, but only a handful of appropriate NIR spectroscopic time series exist. We propose to continue our campaign to roughly double the sample of SN Ia with such data (leveraging our access to a worldwide network of 1m imaging telescopes and twin robotic optical spectrographs) in order to begin to tackle our understanding of NIR spectral diagnostics and how they vary from supernova to supernova. Note that we were allocated time with Gemini South Flamingos-2 in 2013B, but have not triggered any ToO time yet, partially due to the persistent alignment issues with the On-Instrument Wave Front Sensor.

  6. Quantitative Tissue Spectroscopy of Near Infrared Fluorescent Nanosensor Implants.

    PubMed

    Iverson, Nicole M; Bisker, Gili; Farias, Edgardo; Ivanov, Vsevolod; Ahn, Jiyoung; Wogan, Gerald N; Strano, Michael S

    2016-05-01

    Implantable, near infrared (nIR) fluorescent nanosensors are advantageous for in vivo monitoring of biological analytes since they can be rendered selective for a particular target molecule while utilizing their unique optical properties and the nIR tissue transparency window for information transfer without an internal power source or telemetry. However, basic questions remain regarding the optimal encapsulation platform, geometrical properties, and concentration ranges required for high signal to noise ratio and effective detection through biological tissue. In this work, we systematically explore these variables quantitatively to optimize the performance of such optical nanosensors for biomedical applications. We investigate both alginate and polyethylene glycol (PEG) as model hydrogel systems, encapsulating d(GT)15 ssDNA-wrapped single-walled carbon nanotubes (SWNT) as model fluorescent nanoparticle sensors, responsive to riboflavin. Hydrogel sensors implanted 0.5 mm into thick tissue samples exhibit 50% reduction of initial fluorescence intensity, allowing an optical detection limit of 5.4 mm and 5.1 mm depth in tissue for alginate and PEG gels, respectively, at a SWNT concentration of 10 mg L(-1), and 785 nm laser excitation of 80 mW and 30 s exposure. These findings are supported with in vivo nIR fluorescent imaging of SWNT hydrogels implanted subcutaneously in mice. For the case of SWNT, we find that the alginate system is preferable in terms of emission intensity, sensor response, rheological properties, and shelf life. PMID:27305824

  7. Near-infrared fluorescence lifetime pH-sensitive probes.

    PubMed

    Berezin, Mikhail Y; Guo, Kevin; Akers, Walter; Northdurft, Ralph E; Culver, Joseph P; Teng, Bao; Vasalatiy, Olga; Barbacow, Kyle; Gandjbakhche, Amir; Griffiths, Gary L; Achilefu, Samuel

    2011-04-20

    We report what we believe to be the first near-infrared pH-sensitive fluorescence lifetime molecular probe suitable for biological applications in physiological range. Specifically, we modified a known fluorophore skeleton, hexamethylindotricarbocyanine, with a tertiary amine functionality that was electronically coupled to the fluorophore, to generate a pH-sensitive probe. The pK(a) of the probe depended critically on the location of the amine. Peripheral substitution at the 5-position of the indole ring resulted in a compound with pK(a) ∼ 4.9 as determined by emission spectroscopy. In contrast, substitution at the meso-position shifted the pK(a) to 5.5. The resulting compound, LS482, demonstrated steady-state and fluorescence-lifetime pH-sensitivity. This sensitivity stemmed from distinct lifetimes for protonated (∼1.16 ns in acidic DMSO) and deprotonated (∼1.4 ns in basic DMSO) components. The suitability of the fluorescent dyes for biological applications was demonstrated with a fluorescence-lifetime tomography system. The ability to interrogate cellular processes and subsequently translate the findings in living organisms further augments the potential of these lifetime-based pH probes.

  8. [A simple design of functional near-infrared spectroscopy system].

    PubMed

    Xu, Gang; Li, Xiao-li; Liu, Xiao-min

    2015-02-01

    With the development in last twenty years, functional near-infrared spectroscopy (fNIRS) is a non-invasive brain imaging technique which widely used in cognitive neuroscience studies. Based on mechanism of neurovascular coupling, increased functional neural activities in brain induce higher regional cerebral blood flow, which will cause relative concentration change of oxygenated and deoxygenated hemoglobin. In this paper, a single channel continuous wave fNIRS system based on multi-function data acquisition board was proposed. With the benefits of narrow spectral peaks and low divergence, laser diodes provided a better accuracy for measurement with optimal dual-wavelength of 690 and 830 nm. Frequency multiplexing technique was used to distinguish light sources from different emitters, and remove environmental stable interference sources such as ambient light and line power noise as well. LabVIEW was used to design graphical user interface with functionalities including source sequence schedule, auto gain setting, digital inhase and quadrature demodulation, data visualization and storage. The experimental results during holding breath and mental arithmetic task indicated that our system was capable of monitoring regional concentration change of hemoglobin in real time, and detecting activation associated with advanced brain functions. PMID:25970931

  9. Electro-optic sampling of near-infrared waveforms

    NASA Astrophysics Data System (ADS)

    Keiber, Sabine; Sederberg, Shawn; Schwarz, Alexander; Trubetskov, Michael; Pervak, Volodymyr; Krausz, Ferenc; Karpowicz, Nicholas

    2016-03-01

    Access to the complete electric field evolution of a laser pulse is essential for attosecond science in general, and for the scrutiny and control of electron phenomena in solid-state physics specifically. Time-resolved field measurements are routine in the terahertz spectral range, using electro-optic sampling (EOS), photoconductive switches and field-induced second harmonic generation. EOS in particular features outstanding sensitivity and ease of use, making it the basis of time-resolved spectroscopic measurements for studying charge carrier dynamics and active optical devices. In this Letter, we show that careful optical filtering allows the bandwidth of this technique to be extended to wavelengths as short as 1.2 μm (230 THz) with half-cycle durations 2.3 times shorter than the sampling pulse. In a proof-of-principle application, we measure the influence of optical parametric amplification (OPA) on the electric field dynamics of a few-cycle near-infrared (NIR) pulse.

  10. Detecting concealed information using functional near-infrared spectroscopy.

    PubMed

    Sai, Liyang; Zhou, Xiaomei; Ding, Xiao Pan; Fu, Genyue; Sang, Biao

    2014-09-01

    The present study focused on the potential application of fNIRS in the detection of concealed information. Participants either committed a mock crime or not and then were presented with a randomized series of probes (crime-related information) and irrelevants (crime-irrelevant information) in a standard concealed information test (CIT). Participants in the guilty group were instructed to conceal crime-related information they obtained from the mock crime, thus making deceptive response to the probes. Meanwhile, their brain activity to probes and irrelevants was recorded by functional near-infrared spectroscopy (fNIRS). At the group level, we found that probe items were associated with longer reaction times and greater activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex than irrelevant items in the guilty group, but not in the innocent group. These findings provided evidence on neural correlates of recognition during a CIT. Finally, on the basis of the activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex, the correct classification of guilty versus innocent participants was approximately 75 % and the combination of fNIRS and reaction time measures yielded a better classification rate of 83.3 %. These findings illustrate the feasibility and promise of using fNIRS to detect concealed information. PMID:24514911

  11. Non-linear calibration models for near infrared spectroscopy.

    PubMed

    Ni, Wangdong; Nørgaard, Lars; Mørup, Morten

    2014-02-27

    Different calibration techniques are available for spectroscopic applications that show nonlinear behavior. This comprehensive comparative study presents a comparison of different nonlinear calibration techniques: kernel PLS (KPLS), support vector machines (SVM), least-squares SVM (LS-SVM), relevance vector machines (RVM), Gaussian process regression (GPR), artificial neural network (ANN), and Bayesian ANN (BANN). In this comparison, partial least squares (PLS) regression is used as a linear benchmark, while the relationship of the methods is considered in terms of traditional calibration by ridge regression (RR). The performance of the different methods is demonstrated by their practical applications using three real-life near infrared (NIR) data sets. Different aspects of the various approaches including computational time, model interpretability, potential over-fitting using the non-linear models on linear problems, robustness to small or medium sample sets, and robustness to pre-processing, are discussed. The results suggest that GPR and BANN are powerful and promising methods for handling linear as well as nonlinear systems, even when the data sets are moderately small. The LS-SVM is also attractive due to its good predictive performance for both linear and nonlinear calibrations.

  12. In vivo imaging with near-infrared fluorescence lifetime contrast

    NASA Astrophysics Data System (ADS)

    Akers, Walter J.; Berezin, Mikhail Y.; Lee, Hyeran; Achilefu, Samuel

    2009-02-01

    Fluorescence imaging is a mainstay of biomedical research, allowing detection of molecular events in both fixed and living cells, tissues and whole animals. Such high resolution fluorescence imaging is hampered by unwanted signal from intrinsic background fluorescence and scattered light. The signal to background ratio can be improved by using extrinsic contrast agents and greatly enhanced by multispectral imaging methods. Unfortunately, these methods are insufficient for deep tissue imaging where high contrast and speedy acquisition are necessary. Fluorescence lifetime (FLT) is an inherent characteristic of each fluorescent species that can be independent of intensity and spectral properties. Accordingly, FLT-based detection provides an additional contrast mechanism to optical measurements. This contrast is particularly important in the near-infrared (NIR) due to relative transparency of tissue as well as the broad absorption and emission spectra of dyes that are active in this region. Here we report comparative analysis of signal distribution of several NIR fluorescent polymethine dyes in living mice and their correlations with lifetimes obtained in vitro using solution models. The FLT data obtained from dyes dissolved in serum albumin solution correlated well with FLTs measured in vivo. Thus the albumin solution model could be used as a good predictive model for in vivo FLT behavior of newly developed fluorescent reporters. Subsequent experiments in vivo, including monitoring slow release kinetics and detecting proteinuria, demonstrate the complementary nature of FLT for fluorescence intensity imaging.

  13. Near-infrared imaging spectroscopy for counterfeit drug detection

    NASA Astrophysics Data System (ADS)

    Arnold, Thomas; De Biasio, Martin; Leitner, Raimund

    2011-06-01

    Pharmaceutical counterfeiting is a significant issue in the healthcare community as well as for the pharmaceutical industry worldwide. The use of counterfeit medicines can result in treatment failure or even death. A rapid screening technique such as near infrared (NIR) spectroscopy could aid in the search for and identification of counterfeit drugs. This work presents a comparison of two laboratory NIR imaging systems and the chemometric analysis of the acquired spectroscopic image data. The first imaging system utilizes a NIR liquid crystal tuneable filter and is designed for the investigation of stationary objects. The second imaging system utilizes a NIR imaging spectrograph and is designed for the fast analysis of moving objects on a conveyor belt. Several drugs in form of tablets and capsules were analyzed. Spectral unmixing techniques were applied to the mixed reflectance spectra to identify constituent parts of the investigated drugs. The results show that NIR spectroscopic imaging can be used for contact-less detection and identification of a variety of counterfeit drugs.

  14. Investigation of a near-infrared fiber optic immunosensor

    NASA Astrophysics Data System (ADS)

    Daneshvar, Maryam I.; Casay, Guillermo A.; Lipowska, Malgorzata; Patonay, Gabor; Strekowski, Lucjan

    1994-03-01

    The designs of NIR optical fiber immunosensors for the detection of biomolecules are discussed. The use of fiber optics combined with laser-excited fluorescence detection ((lambda) max equals 780 nm) and immunochemical techniques has provided the essential components for developing simpler and more practical, sensitive and selective immunosensors. The antibody is immobilized on the distal end of a surface-activated polymethyl methylacrylate sensor. As the probe is placed in different concentrations of antigenic substance, the antibody reacts with its corresponding antigen through sandwich and/or competitive immunoassays. The concentrations varied from 10 - 100 ng/ml. The near-infrared dye labeled antigen - antibody complex is excited and the emitted fluorescence is collected with a silicon photodiode detector equipped with an 820-nm bandpass filter. In order to determine various factors influencing the immunosensor's performance, the fluorescence intensity responses are obtained under a variety of conditions. The sensor response depending on the type of surface-activating reagent, surface activation period, incubation time, and other measurement conditions also are discussed.

  15. Visible and Near Infrared Fluorescence Spectral Flow Cytometry

    PubMed Central

    Nolan, John P.; Condello, Danilo; Duggan, Erika; Naivar, Mark; Novo, David

    2013-01-01

    There is a long standing interest in measuring complete emission spectra from individual cells in flow cytometry. We have developed flow cytometry instruments and analysis approaches to enable this to be done routinely and robustly. Our spectral flow cytometers use a holographic grating to disperse light from single cells onto a CCD for high speed, wavelength-resolved detection. Customized software allows the single cell spectral data to be displayed and analyzed to produce new spectra-derived parameters. We show that familiar reference and calibration beads can be employed to quantitatively assess instrument performance. We use microspheres stained with six different quantum dots to compare a virtual bandpass filter approach with classic least squares (CLS) spectral unmixing, and then use antibody capture beads and CLS unmixing to demonstrate immunophenotyping of peripheral blood mononuclear cells using spectral flow cytometry. Finally, we characterize and evaluate several near infrared (NIR) emitting fluorophores for use in spectral flow cytometry. Spectral flow cytometry offers a number of attractive features for single cell analysis, including a simplified optical path, high spectral resolution, and streamlined approaches to quantitative multiparameter measurements. The availability of robust instrumentation, software, and analysis approaches will facilitate the development of spectral flow cytometry applications. PMID:23225549

  16. Near-infrared spectroscopy for burning plasma diagnostic applicationsa)

    NASA Astrophysics Data System (ADS)

    Soukhanovskii, V. A.

    2008-10-01

    Ultraviolet and visible (UV-VIS, 200-750nm) atomic spectroscopy of neutral and ionized fuel species (H, D, T, and Li) and impurities (e.g., He, Be, C, and W) is a key element of plasma control and diagnosis on International Thermonuclear Experimental Reactor and future magnetically confined burning plasma experiments (BPXs). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window, and optical fiber transmission under intense neutron and γ-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can be used for machine protection and plasma control applications, as well as contribute to plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to the parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma-facing component temperatures.

  17. Near-infrared (NIR) up-conversion optogenetics

    NASA Astrophysics Data System (ADS)

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-11-01

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650-1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called ‘imaging window’. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system.

  18. Near-infrared (NIR) up-conversion optogenetics.

    PubMed

    Hososhima, Shoko; Yuasa, Hideya; Ishizuka, Toru; Hoque, Mohammad Razuanul; Yamashita, Takayuki; Yamanaka, Akihiro; Sugano, Eriko; Tomita, Hiroshi; Yawo, Hiromu

    2015-11-10

    Non-invasive remote control technologies designed to manipulate neural functions have been long-awaited for the comprehensive and quantitative understanding of neuronal network in the brain as well as for the therapy of neurological disorders. Recently, it has become possible for the neuronal activity to be optically manipulated using biological photo-reactive molecules such as channelrhodopsin (ChR)-2. However, ChR2 and its relatives are mostly reactive to visible light, which does not effectively penetrate through biological tissues. In contrast, near-infrared (NIR) light (650-1450 nm) penetrates deep into the tissues because biological systems are almost transparent to light within this so-called 'imaging window'. Here we used lanthanide nanoparticles (LNPs), composed of rare-earth elements, as luminous bodies to activate ChRs since they absorb low-energy NIR light to emit high-energy visible light (up-conversion). Here, we created a new type of optogenetic system which consists of the donor LNPs and the acceptor ChRs. The NIR laser irradiation emitted visible light from LNPs, then induced the photo-reactive responses in the near-by cells that expressed ChRs. However, there remains room for large improvements in the energy efficiency of the LNP-ChR system.

  19. Near-infrared spectroscopy for rapid classification of fruit spirits.

    PubMed

    Jakubíková, M; Sádecká, J; Kleinová, A; Májek, P

    2016-06-01

    Multivariate analysis combined with near-infrared (NIR) spectral analysis was evaluated to classify fruit spirits. A total of 67 fruit spirits (12 apple, 18 apricot, 19 pear and 18 plum spirits) were analyzed. NIR spectra were collected in the wavenumber range of 4000-10,000 cm(-1). Linear discriminant analysis based on principal component analysis (PCA-LDA) and general discriminant analysis (GDA) based directly on NIR spectral data were used to classify the samples. The prediction performance of models in different wavenumber ranges was also investigated. The best PCA-LDA and GDA models gave a 100 % classification of spirits of the four fruit kinds in the wavenumber range from 5500 to 6050 cm(-1) corresponding to either the C-H stretch of the first overtones of CH3 and CH2 groups, or to compounds containing O-H aromatic groups. The results demonstrated that NIR spectroscopy could be used as a rapid method for classification of fruit spirits. PMID:27478236

  20. Near-infrared autofluorescence for the detection of parathyroid glands

    NASA Astrophysics Data System (ADS)

    Paras, Constantine; Keller, Matthew; White, Lisa; Phay, John; Mahadevan-Jansen, Anita

    2011-06-01

    A major challenge in endocrine surgery is the intraoperative detection of parathyroid glands during both thyroidectomies and parathyroidectomies. Current localization techniques such as ultrasound and sestamibi scan are mostly preoperative and rely on an abnormal parathyroid for its detection. In this paper, we present near-infrared (NIR) autofluorescence as a nonintrusive, real-time, automated in vivo method for the detection of the parathyroid gland. A pilot in vivo study was conducted to assess the ability of NIR fluorescence to identify parathyroid glands during thyroid and parathyroidectomies. Fluorescence measurements at 785 nm excitation were obtained intra-operatively from the different tissues exposed in the neck region in 21 patients undergoing endocrine surgery. The fluorescence intensity of the parathyroid gland was found to be consistently greater than that of the thyroid and all other tissues in the neck of all patients. In particular, parathyroid fluorescence was two to eleven times higher than that of the thyroid tissues with peak fluorescence occurring at 820 to 830 nm. These results indicate that NIR fluorescence has the potential to be an excellent optical tool to locate parathyroid tissue during surgery.

  1. Near-infrared spectroscopy: a methodology-focused review.

    PubMed

    Pellicer, Adelina; Bravo, María del Carmen

    2011-02-01

    Near infrared spectroscopy (NIRS) is a light-based technology used to monitor tissue oxygen status. Refinements to the method since it was first described have extended its applicability to different research and clinical settings due to its non-invasiveness, instrument portability and ease of use. Classic NIRS recordings, based in the Beer-Lambert law, can be used for the trend monitoring of changes in tissue perfusion-oxygenation parting from an arbitrary zero point. However, in order to derive intermittently quantitative values in absolute terms, certain manoeuvres must be performed. More recently, the evolution of the technique has led to the development of instruments that provide an absolute value of regional hemoglobin saturation in a continuous manner. This review will focus on the physical principles of tissue spectroscopy including a brief description of the different operating principles that are currently in use or under development. The theoretical details, experimental procedures and data analysis involved in the measurements of physiological variables using NIRS will be described. The future beyond the scope of NIRS and potential lines of research will also be discussed.

  2. A near-Infrared SETI Experiment: Alignment and Astrometric precision

    NASA Astrophysics Data System (ADS)

    Duenas, Andres; Maire, Jerome; Wright, Shelley; Drake, Frank D.; Marcy, Geoffrey W.; Siemion, Andrew; Stone, Remington P. S.; Tallis, Melisa; Treffers, Richard R.; Werthimer, Dan

    2016-06-01

    Beginning in March 2015, a Near-InfraRed Optical SETI (NIROSETI) instrument aiming to search for fast nanosecond laser pulses, has been commissioned on the Nickel 1m-telescope at Lick Observatory. The NIROSETI instrument makes use of an optical guide camera, SONY ICX694 CCD from PointGrey, to align our selected sources into two 200µm near-infrared Avalanche Photo Diodes (APD) with a field-of-view of 2.5"x2.5" each. These APD detectors operate at very fast bandwidths and are able to detect pulse widths extending down into the nanosecond range. Aligning sources onto these relatively small detectors requires characterizing the guide camera plate scale, static optical distortion solution, and relative orientation with respect to the APD detectors. We determined the guide camera plate scale as 55.9+- 2.7 milli-arcseconds/pixel and magnitude limit of 18.15mag (+1.07/-0.58) in V-band. We will present the full distortion solution of the guide camera, orientation, and our alignment method between the camera and the two APDs, and will discuss target selection within the NIROSETI observational campaign, including coordination with Breakthrough Listen.

  3. Automatic and Accurate Shadow Detection Using Near-Infrared Information.

    PubMed

    Rüfenacht, Dominic; Fredembach, Clément; Süsstrunk, Sabine

    2014-08-01

    We present a method to automatically detect shadows in a fast and accurate manner by taking advantage of the inherent sensitivity of digital camera sensors to the near-infrared (NIR) part of the spectrum. Dark objects, which confound many shadow detection algorithms, often have much higher reflectance in the NIR. We can thus build an accurate shadow candidate map based on image pixels that are dark both in the visible and NIR representations. We further refine the shadow map by incorporating ratios of the visible to the NIR image, based on the observation that commonly encountered light sources have very distinct spectra in the NIR band. The results are validated on a new database, which contains visible/NIR images for a large variety of real-world shadow creating illuminant conditions, as well as manually labeled shadow ground truth. Both quantitative and qualitative evaluations show that our method outperforms current state-of-the-art shadow detection algorithms in terms of accuracy and computational efficiency.

  4. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    PubMed Central

    Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects.

  5. Near-Infrared Grating Spectrometer for Mobile Phone Applications

    PubMed Central

    Knobbe, Jens; Grüger, Heinrich

    2016-01-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro–electro–mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm3. Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications. PMID:27170776

  6. Studying hot exozodiacal dust with near-infrared interferometry

    NASA Astrophysics Data System (ADS)

    Absil, Olivier; Defrère, Denis; Le Bouquin, Jean-Baptiste; Mollier, Benjamin; Augereau, Jean-Charles; Coudé du Foresto, Vincent; Di Folco, Emmanuel; Ertel, Steve; ten Brummelaar, Theo

    2012-07-01

    Since our first detection of a resolved near-infrared emission around the main sequence star Vega, which we identified as the signature of hot dust grains close to the sublimation limit, we have been systematically searching for similar signatures around a magnitude-limited sample of nearby main sequence stars with the FLUOR instrument at the CHARA array. About 40 targets with spectral types ranging from A to K have been observed within the last 6 years, leading to first statistical trends on the occurence of the bright exozodi phenomenon as a function of spectral type. Our target sample is balanced between stars known to harbour cold dust populations from space-based missions (e.g., Spitzer, Herschel) and stars without cold dust, so that the occurence of abundant hot dust can also be correlated with the presence of large reservoirs of cold planetesimals. In this paper, we present preliminary conclusions from the CHARA/FLUOR survey. We also discuss the first results obtained in 2011/2012 with the new PIONIER visiting instrument at the VLTI, which is now used to extend our survey sample to the Southern hemisphere and to fainter targets. A first measurement of the exozodi/star flux ratio as a function of wavelength within the H band is presented, thanks to the low spectral resolution capability of PIONIER. Finally, we also briefly discuss our plans for extending the survey to fainter targets in the Northern hemisphere with an upgraded version of the FLUOR beam combiner.

  7. Near infrared spectroscopy based brain-computer interface

    NASA Astrophysics Data System (ADS)

    Ranganatha, Sitaram; Hoshi, Yoko; Guan, Cuntai

    2005-04-01

    A brain-computer interface (BCI) provides users with an alternative output channel other than the normal output path of the brain. BCI is being given much attention recently as an alternate mode of communication and control for the disabled, such as patients suffering from Amyotrophic Lateral Sclerosis (ALS) or "locked-in". BCI may also find applications in military, education and entertainment. Most of the existing BCI systems which rely on the brain's electrical activity use scalp EEG signals. The scalp EEG is an inherently noisy and non-linear signal. The signal is detrimentally affected by various artifacts such as the EOG, EMG, ECG and so forth. EEG is cumbersome to use in practice, because of the need for applying conductive gel, and the need for the subject to be immobile. There is an urgent need for a more accessible interface that uses a more direct measure of cognitive function to control an output device. The optical response of Near Infrared Spectroscopy (NIRS) denoting brain activation can be used as an alternative to electrical signals, with the intention of developing a more practical and user-friendly BCI. In this paper, a new method of brain-computer interface (BCI) based on NIRS is proposed. Preliminary results of our experiments towards developing this system are reported.

  8. Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission.

    PubMed

    Capak, P L; Carilli, C; Jones, G; Casey, C M; Riechers, D; Sheth, K; Carollo, C M; Ilbert, O; Karim, A; LeFevre, O; Lilly, S; Scoville, N; Smolcic, V; Yan, L

    2015-06-25

    The rest-frame ultraviolet properties of galaxies during the first three billion years of cosmic time (redshift z > 4) indicate a rapid evolution in the dust obscuration of such galaxies. This evolution implies a change in the average properties of the interstellar medium, but the measurements are systematically uncertain owing to untested assumptions and the inability to detect heavily obscured regions of the galaxies. Previous attempts to measure the interstellar medium directly in normal galaxies at these redshifts have failed for a number of reasons, with two notable exceptions. Here we report measurements of the forbidden C ii emission (that is, [C II]) from gas, and the far-infrared emission from dust, in nine typical star-forming galaxies about one billion years after the Big Bang (z ≈ 5-6). We find that these galaxies have thermal emission that is less than 1/12 that of similar systems about two billion years later, and enhanced [C II] emission relative to the far-infrared continuum, confirming a strong evolution in the properties of the interstellar medium in the early Universe. The gas is distributed over scales of one to eight kiloparsecs, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z < 3 and being comparable in dust content to local low-metallicity systems.

  9. Galaxies at redshifts 5 to 6 with systematically low dust content and high [C II] emission.

    PubMed

    Capak, P L; Carilli, C; Jones, G; Casey, C M; Riechers, D; Sheth, K; Carollo, C M; Ilbert, O; Karim, A; LeFevre, O; Lilly, S; Scoville, N; Smolcic, V; Yan, L

    2015-06-25

    The rest-frame ultraviolet properties of galaxies during the first three billion years of cosmic time (redshift z > 4) indicate a rapid evolution in the dust obscuration of such galaxies. This evolution implies a change in the average properties of the interstellar medium, but the measurements are systematically uncertain owing to untested assumptions and the inability to detect heavily obscured regions of the galaxies. Previous attempts to measure the interstellar medium directly in normal galaxies at these redshifts have failed for a number of reasons, with two notable exceptions. Here we report measurements of the forbidden C ii emission (that is, [C II]) from gas, and the far-infrared emission from dust, in nine typical star-forming galaxies about one billion years after the Big Bang (z ≈ 5-6). We find that these galaxies have thermal emission that is less than 1/12 that of similar systems about two billion years later, and enhanced [C II] emission relative to the far-infrared continuum, confirming a strong evolution in the properties of the interstellar medium in the early Universe. The gas is distributed over scales of one to eight kiloparsecs, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z < 3 and being comparable in dust content to local low-metallicity systems. PMID:26108853

  10. The remnant of a merger between two dwarf galaxies in Andromeda II.

    PubMed

    Amorisco, N C; Evans, N W; van de Ven, G

    2014-03-20

    Driven by gravity, massive structures like galaxies and clusters of galaxies are believed to grow continuously through hierarchical merging and accretion of smaller systems. Observational evidence of accretion events is provided by the coherent stellar streams crossing the outer haloes of massive galaxies, such as the Milky Way or Andromeda. At similar mass scales, around 10(11) solar masses in stars, further evidence of merging activity is also ample. Mergers of lower-mass galaxies are expected within the hierarchical process of galaxy formation, but have hitherto not been seen for galaxies with less than about 10(9) solar masses in stars. Here we report the kinematic detection of a stellar stream in one of the satellite galaxies of Andromeda, the dwarf spheroidal Andromeda II, which has a mass of only 10(7) solar masses in stars. The properties of the stream show that we are observing the remnant of a merger between two dwarf galaxies. This had a drastic influence on the dynamics of the remnant, which is now rotating around its projected major axis. The stellar stream in Andromeda II illustrates the scale-free character of the formation of galaxies, down to the lowest galactic mass scales.

  11. The remnant of a merger between two dwarf galaxies in Andromeda II.

    PubMed

    Amorisco, N C; Evans, N W; van de Ven, G

    2014-03-20

    Driven by gravity, massive structures like galaxies and clusters of galaxies are believed to grow continuously through hierarchical merging and accretion of smaller systems. Observational evidence of accretion events is provided by the coherent stellar streams crossing the outer haloes of massive galaxies, such as the Milky Way or Andromeda. At similar mass scales, around 10(11) solar masses in stars, further evidence of merging activity is also ample. Mergers of lower-mass galaxies are expected within the hierarchical process of galaxy formation, but have hitherto not been seen for galaxies with less than about 10(9) solar masses in stars. Here we report the kinematic detection of a stellar stream in one of the satellite galaxies of Andromeda, the dwarf spheroidal Andromeda II, which has a mass of only 10(7) solar masses in stars. The properties of the stream show that we are observing the remnant of a merger between two dwarf galaxies. This had a drastic influence on the dynamics of the remnant, which is now rotating around its projected major axis. The stellar stream in Andromeda II illustrates the scale-free character of the formation of galaxies, down to the lowest galactic mass scales. PMID:24572352

  12. Measuring stellar magnetic fields from high resolution spectroscopy of near-infrared lines

    NASA Astrophysics Data System (ADS)

    Leone, F.; Vacca, W. D.; Stift, M. J.

    2003-10-01

    Zeeman splitting of otherwise degenerate levels provides a straight-forward method of measuring stellar magnetic fields. In the optical, the relative displacements of the Zeeman components are quite small compared to the rotational line broadening, and therefore observations of Zeeman splitting are usually possible only for rather strong magnetic fields in very slowly rotating stars. However, the magnitude of the Zeeman splitting is proportional to the square of the wavelength, whereas rotational line broadening mechanisms are linear in wavelength; therefore, there is a clear advantage in using near-infrared spectral lines to measure surface stellar magnetic fields. We have obtained high resolution (R >= 25 000) spectra in the 15 625-15 665 Å region for two magnetic chemically peculiar stars, viz. HD 176232 and HD 201601, and for the suspected magnetic chemically peculiar star HD 180583, as part of a pilot study aimed at determining the accuracy with which we can measure stellar magnetic fields using the Zeeman splitting of near-infrared lines. We confirm that in principle the magnetic field strength can be estimated from the magnetic intensification of spectral lines, i.e. the increase in equivalent width of a line over the zero-field value. However, due to line blending as well as the dependence of this intensification on abundance and field geometry, accurate estimates of the magnetic field strengths can be obtained only by modelling the line profiles by means of spectral synthesis techniques. Using this approach, we find a 1.4 kG magnetic field modulus in HD 176132 and an upper limit of 0.2 kG in HD 180583. The very weak infrared lines in the spectrum of HD 201601 are consistent with a 3.9 kG field modulus estimated from the splitting of the Fe II 6149.258 Å line seen in an optical spectrum. Finally, we would like to draw attention to the fact that there are no sufficiently detailed and reliable atomic line lists available for the near-infrared region that

  13. The Subaru FMOS galaxy redshift survey (FastSound). II. The emission line catalog and properties of emission line galaxies

    NASA Astrophysics Data System (ADS)

    Okada, Hiroyuki; Totani, Tomonori; Tonegawa, Motonari; Akiyama, Masayuki; Dalton, Gavin; Glazebrook, Karl; Iwamuro, Fumihide; Ohta, Kouji; Takato, Naruhisa; Tamura, Naoyuki; Yabe, Kiyoto; Bunker, Andrew J.; Goto, Tomotsugu; Hikage, Chiaki; Ishikawa, Takashi; Okumura, Teppei; Shimizu, Ikkoh

    2016-06-01

    We present basic properties of ˜3300 emission line galaxies detected by the FastSound survey, which are mostly Hα emitters at z ˜ 1.2-1.5 in the total area of about 20 deg2, with the Hα flux sensitivity limit of ˜1.6 × 10-16 erg cm-2 s-1 at 4.5 σ. This paper presents the catalog of the FastSound emission lines and galaxies, which is open to the public. We also present basic properties of typical FastSound Hα emitters, which have Hα luminosities of 1041.8-1043.3 erg s-1, star formation rates (SFRs) of 20-500 M⊙ yr-1, and stellar masses of 1010.0-1011.3 M⊙. The 3D distribution maps for the four fields of Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) W1-4 are presented, clearly showing large scale clustering of galaxies at the scale of ˜100-600 comoving Mpc. Based on 1105 galaxies with detections of multiple emission lines, we estimate that the contamination of non-Hα lines is about 4% in the single-line emission galaxies, which is mostly [O III]λ5007. This contamination fraction is also confirmed by the stacked spectrum of all the FastSound spectra, in which Hα, [N II]λλ6548,6583, [S II]λλ6717,6731, and [O I]λλ6300,6364 are seen.

  14. Comparing the host galaxies of type Ia, type II, and type Ibc supernovae

    SciTech Connect

    Shao, X.; Liang, Y. C.; Chen, X. Y.; Zhong, G. H.; Deng, L. C.; Zhang, B.; Shi, W. B.; Zhou, L.; Dennefeld, M.; Hammer, F.; Flores, H. E-mail: ycliang@bao.ac.cn

    2014-08-10

    We compare the host galaxies of 902 supernovae (SNe), including SNe Ia, SNe II, and SNe Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the Sloan Digital Sky Survey (SDSS) Data Release 7. We selected an additional 213 galaxies by requiring the light fraction of spectral observations to be >15%, which could represent well the global properties of the galaxies. Among these 213 galaxies, 135 appear on the Baldwin-Phillips-Terlevich diagram, which allows us to compare the hosts in terms of whether they are star-forming (SF) galaxies, active galactic nuclei (AGNs; including composites, LINERs, and Seyfert 2s) or absorption-line galaxies (Absorps; i.e., their related emission lines are weak or non-existent). The diagrams related to the parameters D{sub n}(4000), Hδ{sub A}, stellar masses, star formation rates (SFRs), and specific SFRs for the SNe hosts show that almost all SNe II and most of the SNe Ibc occur in SF galaxies, which have a wide range of stellar masses and low D{sub n}(4000). The SNe Ia hosts as SF galaxies following similar trends. A significant fraction of SNe Ia occurs in AGNs and absorption-line galaxies, which are massive and have high D{sub n}(4000). The stellar population analysis from spectral synthesis fitting shows that the hosts of SNe II have a younger stellar population than hosts of SNe Ia. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures less than 15% of the total light. These comparison galaxies appear biased toward higher 12+log(O/H) (∼0.1 dex) at a given stellar mass. Therefore, we believe the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.

  15. Penetrating the Homunculus—Near-Infrared Adaptive Optics Images of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Artigau, Étienne; Martin, John C.; Humphreys, Roberta M.; Davidson, Kris; Chesneau, Olivier; Smith, Nathan

    2011-06-01

    Near-infrared adaptive optics imaging with the Near-Infrared Coronagraphic Imager (NICI) and NaCO reveal what appears to be a three-winged or lobed pattern, the "butterfly nebula," outlined by bright Brγ and H2 emission and light scattered by dust. In contrast, the [Fe II] emission does not follow the outline of the wings, but shows an extended bipolar distribution which is tracing the Little Homunculus ejected in η Car's second or lesser eruption in the 1890s. Proper motions measured from the combined NICI and NaCO images together with radial velocities show that the knots and filaments that define the bright rims of the butterfly were ejected at two different epochs corresponding approximately to the great eruption and the second eruption. Most of the material is spatially distributed 10°-20° above and below the equatorial plane apparently behind the Little Homunculus and the larger SE lobe. The equatorial debris either has a wide opening angle or the clumps were ejected at different latitudes relative to the plane. The butterfly is not a coherent physical structure or equatorial torus but spatially separate clumps and filaments ejected at different times, and now 2000-4000 AU from the star. Based on observations obtained at the Gemini Observatory (program ID: GS-2008B-DD-6), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  16. Wide-field near-infrared fluorescence endoscope for real-time in vivo imaging

    NASA Astrophysics Data System (ADS)

    Liu, Zhongyao; Miller, Sharon J.; Joshi, Bishnu P.; Wang, Thomas D.

    2012-02-01

    A diode-pumped solid state laser is used to deliver excitation at λex = 671 nm. The beam is expanded by a pair of relay lenses (f1 = 30 and f2 = 50 mm) to 3 mm diameter, filling the aperture of a fluid light cable that is coupled to a Hopkins II rigid endoscope. Near-infrared fluorescence images are collected by the endoscope and transmitted by another set of relay lenses onto a CCD detector that has dimensions of 8.7x6.9 mm2 (1388x1040 pixels). A zoom lens system (F#1.6-16 aperture) with a tunable focal length (20-100 mm) magnifies the image to fill the dimensions of the CCD. A band pass filter allows fluorescence with spectral range λem = 696 to 736 nm to be collected. The system achieves a resolution of 9.8 μm and field-of-view of 3.6 mm at a distance of 2.5 mm between the distal end of the endoscope and the tissue. Images are collected at a rate of 10 frames per second. A filter wheel is incorporated into the handle of the instrument housing to rapidly switch between reflectance and fluorescence images. Cy5.5-labeled peptides were delivered through the 1 mm diameter instrument channel in the endoscope. Near-infrared fluorescence images demonstrated specific peptide binding to spontaneous adenomas that developed beginning at 2 months of age in a genetically-engineered mouse with mutation of one allele in the APC gene. This integrated methodology represents a powerful tool that can achieve real time detection of disease in the colon and other hollow organs.

  17. Characterization of red-near infrared transition for wheat and chickpea using 3 nm bandwidth data

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Vijayan, D.; Prasad, T. S.

    2001-01-01

    Enhancement of space based capabilities to discriminate different crops and different varieties of a particular crop needs measurement of (i) the shift in red edge and (ii) the slope of the sudden rise of reflectance in 680 - 760 nm spectral region as a function of Days After Sowing (DAS). To develop the knowledge base for catering to the analysis of future space-based hyperspectral measurements, ground based measurements in 3 nm bandwidth in visible - near Infrared region together with corresponding Leaf Area Index (LAI) observations were taken over the Crop Growth Cycle (CGC) of Wheat and Chickpea. The red edge for wheat crop was at 679 nm for 25 DAS and reached the upper limit i.e., 693.7 nm at 84 DAS and thereafter shifted backward to 679 nm at 108 DAS. There was no change in red edge value of 684.9 nm during 40 to 49 DAS and of 687.8 nm during 55 to 71 DAS. The slope of Red to NIR transition for wheat varied from 0.457 to peak value of 0.784 during 25 to 71 DAS and thereafter decreased to 0.073 at 108 DAS. The peak of Red to Near Infrared (NIR) transition slope and Ratio Vegetation Index (RVI) occurred at the same time i.e., 71 DAS. However, the upper most value of red edge shift occurred at 84 DAS. Paper discusses the above aspects including role of mid point of Red to NIR transition, interrelationships among the Red-NIR transition Slope, Red Edge, LAI and RVI for wheat and chickpea.

  18. The Internal Kinematics of the H II Galaxy II Zw 40

    NASA Astrophysics Data System (ADS)

    Bordalo, Vinicius; Plana, Henri; Telles, Eduardo

    2009-05-01

    We present a study of the kinematic properties of the ionized gas in the dominant giant H II region of the well known H II galaxy: II Zw 40. High spatial and spectral resolution spectroscopy has been obtained using the Integral Field Unit mode on the Gemini Multi-Object Spectrograph instrument at the Gemini-North7Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (USA), the Science and Technology Facilities Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina). telescope. The observations allow us to obtain the Hα intensity map, the radial velocity and velocity dispersion maps as well as estimate some physical conditions in the inner region of the starburst, such as oxygen abundance (O/H) and electron density. We have used a set of kinematics diagnostic diagrams, such as the intensity versus velocity dispersion (I-σ), intensity versus radial velocity (I-V), and V-σ, for global and individual analysis in the subregions of the nebula. We aim to separate the main line broadening mechanisms responsible for producing a smooth supersonic integrated line profile for the giant H II region. Bubbles and shells driven by stellar winds and possibly supernovae, covering a large fraction on the face of the nebula, are identified on scales larger than 50 pc. We found that unperturbed or "free from shells" regions showing the lowest σ values (~20 km s-1) should be good indicators for the σgrav component in II Zw 40. The brightest central region (R ~ 50 pc) is responsible for σ derived from a single fit to the integrated line profile. The dominant action of gravity, and possibly unresolved winds of young (<10 Myr) massive stars, in this small region should be responsible for

  19. 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.

  20. MOIRCS Deep Survey. IX. Deep Near-Infrared Imaging Data and Source Catalog

    NASA Astrophysics Data System (ADS)

    Kajisawa, Masaru; Ichikawa, Takashi; Tanaka, Ichi; Yamada, Toru; Akiyama, Masayuki; Suzuki, Ryuji; Tokoku, Chihiro; Katsuno Uchimoto, Yuka; Konishi, Masahiro; Yoshikawa, Tomohiro; Nishimura, Tetsuo; Omata, Koji; Ouchi, Masami; Iwata, Ikuru; Hamana, Takashi; Onodera, Masato

    2011-03-01

    We present deep J-, H-, and Ks-band imaging data of the MOIRCS Deep Survey (MODS), which was carried out with the Multi-Object Infrared Camera and Spectrograph (MOIRCS) mounted on the Subaru Telescope in the GOODS-North region. The data reach 5σ total limiting magnitudes for point sources of J = 23.9, H = 22.8, and Ks = 22.8 (Vega magnitude) over 103 arcmin2 (wide field). In 28 arcmin2 of the survey area, which is an ultra-deep field of the MODS (deep field), the data reach 5σ depths of J = 24.8, H = 23.4, and Ks = 23.8. The spatial resolutions of the combined images are FWHM ˜0''.6 and ˜0''.5 for the wide and deep fields in all bands, respectively. Combining the MODS data with the multi-wavelength public data taken with the HST, Spitzer, and other ground-based telescopes in the GOODS field, we constructed a multi-wavelength photometric catalog of Ks-selected sources. Using the catalog, we present Ks-band number counts and near-infrared color distribution of the detected objects; we also demonstrate some selection techniques with the NIR colors for high redshift galaxies. These data and catalog are publicly available via Internet.

  1. First Detection of Galactic Latitude Dedpendence of Near-infrared Diffuse Galactic Light from DIRBE Renalysis

    NASA Astrophysics Data System (ADS)

    Sano, K.; Matsuura, S.; Tsumura, K.; Arai, T.; Shirahata, M.; Onishi, Y.

    2016-04-01

    Observational study on near-infrared (IR) scattering properties of interstellar dust grains has been limited due to its faintness. Using all-sky maps obtained from the Diffuse Infrared Background Experiment, we investigate the scattering property from diffuse Galactic light (DGL) measurements at 1.25, 2.2, and 3.5 μ {{m}}, in addition to our recent analyses of diffuse near-IR emission. As a result, we first find that the intensity ratios of near-IR DGL to 100 μ {{m}} emission increase toward low Galactic latitudes at 1.25 and 2.2 μ {{m}}. The derived latitude dependence can be reproduced by a scattered light model of interstellar dust with a large scattering asymmetry factor g\\equiv < {cos}θ > of {0.8}-0.3+0.2 at 1.25 and 2.2 μ {{m}}, assuming an infinite Galaxy disk as an illuminating source. The derived asymmetry factor is comparable to the values obtained in the optical, but several times larger than that expected from a recent dust model. Since a possible latitude dependence of ultraviolet-excited dust emission at 1.25 and 2.2 μ {{m}} would reduce the large asymmetry factor to the reasonable value, our result may indicate the first detection of such an additional emission component in the diffuse interstellar medium.

  2. Near infrared photometric and optical spectroscopic study of 22 low mass star clusters embedded in nebulae

    NASA Astrophysics Data System (ADS)

    Soares, J. B.; Bica, E.; Ahumada, A. V.; Clariá, J. J.

    2008-02-01

    Aims:Among the star clusters in the Galaxy, those embedded in nebulae represent the youngest group, which has only recently been explored. The analysis of a sample of 22 candidate embedded stellar systems in reflection nebulae and/or HII environments is presented. Methods: We employed optical spectroscopic observations of stars in the directions of the clusters carried out at CASLEO (Argentina) together with near infrared photometry from the 2MASS catalogue. Our analysis is based on source surface density, colour-colour diagrams and on theoretical pre-main sequence isochrones. We take into account the field star contamination by carrying out a statistical subtraction. Results: The studied objects have the characteristics of low mass systems. We derive their fundamental parameters. Most of the cluster ages are younger than 2 Myr. The studied embedded stellar systems in reflection nebulae and/or HII region complexes do not have stars of spectral types earlier than B. The total stellar masses locked in the clusters are in the range 20-220 M⊙. They are found to be gravitationally unstable and are expected to dissolve in a timescale of a few Myr. Based on observations made at Complejo Astronómico El Leoncito, which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juan, Argentina.

  3. Detecting and Segregating Black Tip-Damaged Wheat Kernels Using Visible and Near Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection of individual wheat kernels with black tip symptom (BTS) and black tip damage (BTD) was demonstrated using near infrared reflectance spectroscopy (NIRS) and silicon light-emitting-diode (LED) based instruments. The two instruments tested, a single kernel near-infrared spectroscopy instrume...

  4. 77 FR 16925 - Medical Devices; Neurological Devices; Classification of the Near Infrared Brain Hematoma Detector

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ... HUMAN SERVICES Food and Drug Administration 21 CFR Part 882 Medical Devices; Neurological Devices; Classification of the Near Infrared Brain Hematoma Detector AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is classifying the Near Infrared (NIR)...

  5. Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus.

    PubMed

    Walther, L E; Asenov, D R; Di Martino, E

    2011-04-01

    Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

  6. Reliability of Near-Infrared Spectroscopy for Determining Muscle Oxygen Saturation during Exercise

    ERIC Educational Resources Information Center

    Austin, Krista G.; Daigle, Karen A.; Patterson, Patricia; Cowman, Jason; Chelland, Sara; Haymes, Emily M.

    2005-01-01

    Near-infrared spectroscopy is currently used to assess changes in the oxygen saturation of the muscle during exercise. The primary purpose of this study was to assess the reliability of near-infrared spectroscopy in determining muscle oxygen saturation (StO[subscript 2]) in the vastus lateralis during cycling and the gastrocnemius during running…

  7. Effect of mechanical optical clearing on near-infrared spectroscopy.

    PubMed

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations. PMID:26041069

  8. Implanted near-infrared spectroscopy for cardiac monitoring

    NASA Astrophysics Data System (ADS)

    Bhunia, Sourav K.; Cinbis, Can

    2011-02-01

    Implanted Cardioverter Defibrillator (ICD) provides one of the most effective therapies for the prevention of sudden cardiac death, but also delivers some high voltage shocks inappropriately, causing morbidity and mortality. Implanted near-infrared spectroscopy (NIRS) may augment ICD arrhythmia detection by monitoring skeletal muscle perfusion. A two-wavelength, single-distance, continuous-wave implanted NIRS has been evaluated in-vivo. A weighted difference of the changes in attenuation at two wavelengths, across the isobestic point of the hemoglobin spectra, was taken to be the microvascular oxygenation trend indicator (O2 Index). Although the exact weight depends on the local vascular distribution and their oxygen levels, the hypothesis that a constant weight may be adequate for hemodynamic trending during short arrhythmic episodes, was tested. The sensor was implanted subcutaneously both on fresh tissue and inside scar tissue that formed around a pre-existing implant, in 3 animals each. Attenuations were recorded at 660 and 890 nm during normal sinus rhythm (NSR) and induced ventricular fibrillation (VF). The slope of the O2 Index over 10 seconds was computed for 7 NSR and 8 VF episodes in fresh and 13 NSR and 15 VF episodes in scar tissue pockets. The mean O2 Index slope was significantly different (p<0.0001) between NSR and VF rhythms for both the fresh and scar tissue pockets. Therefore implanted NIRS may be useful for preventing inappropriate detection of VF during electromagnetic interference, double counting of ECG T-wave as an R-wave, ICD lead failure, electrocardiographic aberrancy etc.

  9. Development of silicon-germanium visible-near infrared arrays

    NASA Astrophysics Data System (ADS)

    Zeller, John W.; Rouse, Caitlin; Efstathiadis, Harry; Haldar, Pradeep; Lewis, Jay S.; Dhar, Nibir K.; Wijewarnasuriya, Priyalal; Puri, Yash R.; Sood, Ashok K.

    2016-05-01

    Photodetectors based on germanium which do not require cooling and can provide good near-infrared (NIR) detection performance offer a low-cost alternative to conventional infrared sensors based on material systems such as InGaAs, InSb, and HgCdTe. As a result of the significant difference in thermal expansion coefficients between germanium and silicon, tensile strain incorporated into Ge epitaxial layers deposited on Si utilizing specialized growth processes can extend the operational range of detection to 1600 nm and longer wavelengths. We have fabricated Ge based PIN photodetectors on 300 mm diameter Si wafers to take advantage of high throughput, large-area complementary metal-oxide semiconductor (CMOS) technology. This device fabrication process involves low temperature epitaxial deposition of Ge to form a thin p+ (boron) Ge seed/buffer layer, and subsequent higher temperature deposition of a thicker Ge intrinsic layer. This is followed by selective ion implantation of phosphorus of various concentrations to form n+ Ge regions, deposition of a passivating oxide cap, and then top copper contacts to complete the PIN detector devices. Various techniques including transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) have been employed to characterize the material and structural properties of the epitaxially grown layers and fabricated detector devices, and these results are presented. The I-V response of the photodetector devices with and without illumination was also measured, for which the Ge based photodetectors consistently exhibited low dark currents of around ~1 nA at -1 V bias.

  10. Intraoperative Near-Infrared Imaging Can Identify Pulmonary Nodules

    PubMed Central

    Okusanya, Olugbenga T.; Holt, David; Heitjan, Daniel; Deshpande, Charuhas; Venegas, Ollin; Jiang, Jack; Judy, Ryan; DeJesus, Elizabeth; Madajewski, Brian; Oh, Kenny; Albelda, Steven M.; Nie, Shuming; Singhal, Sunil

    2014-01-01

    Background Over 80,000 people undergo pulmonary resection for a lung nodule in the United States each year. Small nodules are frequently missed or difficult to find despite preoperative imaging. We hypothesized that near-infrared (NIR) imaging technology could be used to identify and locate lung nodules during surgery. Methods We enrolled 18 patients who were diagnosed with a pulmonary nodule that required resection. All patients had a fine-cut 1mm computed tomography scan preoperatively. The patients were given systemic 5 mg/kg indocyanine green (ICG) and then underwent an open thoracotomy 24 hours later. NIR imaging was used to identify the primary nodule and search for additional nodules that were not found by visual inspection or manual palpation of the ipsilateral lung. Results Manual palpation and visual inspection identified all 18 primary pulmonary nodules and no additional lesions. Intraoperative NIR imaging detected 16 out of the 18 primary nodules. NIR imaging also identified 5 additional subcentimeter nodules: 3 metastatic adenocarcinomas and 2 metastatic sarcomas. This technology could identify nodules as small as 0.2 cm and as deep as 1.3 cm from the pleural surface. This approach discovered 3 nodules that were in different lobes than the primary tumor. Nodule fluorescence was independent of size, metabolic activity, histology, tumor grade and vascularity. Conclusions This is the first-in-human demonstration of identifying pulmonary nodules during Thoracic surgery with NIR imaging without a priori knowledge of their location or existence. NIR imaging can detect pulmonary nodules during lung resections that are poorly visualized on computed tomography and difficult to discriminate on finger palpation. PMID:25106680

  11. Near-infrared Variability in the Orion Nebula Cluster

    NASA Astrophysics Data System (ADS)

    Rice, Thomas S.; Reipurth, Bo; Wolk, Scott J.; Vaz, Luiz Paulo; Cross, N. J. G.

    2015-10-01

    Using UKIRT on Mauna Kea, we have carried out a new near-infrared J, H, K monitoring survey of almost a square degree of the star-forming Orion Nebula Cluster with observations on 120 nights over three observing seasons, spanning a total of 894 days. We monitored ˜15,000 stars down to J≈ 20 using the WFCAM instrument, and have extracted 1203 significantly variable stars from our data. By studying variability in young stellar objects (YSOs) in the H - K, K color-magnitude diagram, we are able to distinguish between physical mechanisms of variability. Many variables show color behavior indicating either dust-extinction or disk/accretion activity, but we find that when monitored for longer periods of time, a number of stars shift between these two variability mechanisms. Further, we show that the intrinsic timescale of disk/accretion variability in young stars is longer than that of dust-extinction variability. We confirm that variability amplitude is statistically correlated with evolutionary class in all bands and colors. Our investigations of these 1203 variables have revealed 73 periodic AA Tau type variables, many large-amplitude and long-period (P\\gt 15 days) YSOs, including three stars showing widely spaced periodic brightening events consistent with circumbinary disk activity, and four new eclipsing binaries. These phenomena and others indicate the activity of long-term disk/accretion variability processes taking place in young stars. We have made the light curves and associated data for these 1203 variables available online.

  12. MOS spectroscopy with the JWST Near-Infrared Spectrometer

    NASA Astrophysics Data System (ADS)

    Karakla, Diane M.; Beck, Tracy; Gilbert, Karoline; Pontoppidan, Klaus Martin; Curtis, Gary; Shyrokov, Alexander

    2015-08-01

    The James Webb Space Telescope's Near-Infrared Spectrograph (NIRSpec) will feature astronomy’s first space-based, multi-object spectroscopic (MOS) capability enabled by the instrument’s micro-shutter array (MSA). The MSA is a four-quadrant fixed grid of nearly 250,000 tiny shutters that can be configured into slits on multiple astronomical targets in a field. In MOS mode, NIRSpec can obtain spectra of more than 100 targets simultaneously in one of three spectral bands (1.0 - 1.8 μm, 1.7 - 3.0 μm, and 2.9 - 5.0 μm) at medium (R~1000) or high resolution (R~2700) with the gratings, or at lower resolution (R~100, 0.6 - 5.0 μm) with the PRISM. The NIRSpec team and software developers at the Space Telescope Science Institute (STScI) have developed an MSA Planning Tool (MPT) to facilitate the complex observation planning process for a variety of observing strategies. The purpose of the tool is to find optimal pointings on the sky where many sources (or many high-valued sources) can be observed at a given pointing, or through a set of telescope dithers, and to design the associated MSA configurations at each position. The MPT is available to the astronomical community as part of the Astronomer’s Proposal Tool (APT), an integrated software package developed by STScI for the preparation of observing proposals. We will summarize the operational concept for MOS spectroscopy with the instrument, describe the MSA Planning Tool and its algorithms, and highlight recent developments that extend the tool’s applicability to diverse science cases.

  13. Visible-Near Infrared Imaging Spectrometer Data of Explosion Craters

    NASA Technical Reports Server (NTRS)

    Farr, T. G.

    2005-01-01

    In a continuing study to capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained new high resolution visible-near infrared images of several explosion craters at the Nevada Test Site. We used the Airborne Visible-Infrared Imaging Spectrometer (AVIRIS) to obtain images in 224 spectral bands from 0.4-2.5 microns [1]. The main craters that were imaged were Sedan, Scooter, Schooner, Buggy, and Danny Boy [2]. The 390 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of the detonation of a 104 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a "simple" crater [2]. Sedan was formed in alluvium of mixed lithology [3] and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also imaged by AVIRIS. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m, Fig. 1) craters were also important targets for AVIRIS as they were excavated in hard welded tuff and basaltic andesite, respectively [3, 4]. This variation in targets will allow the study of ejecta patterns, compositional modifications due to the explosions, and the role of craters as subsurface probes.

  14. Fetal oxygenation measurement using wireless near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Macnab, Andrew; Shadgan, Babak; Janssen, Patricia; Rurak, Dan

    2012-03-01

    Background: Fetal well-being is determined in large part by how well the placenta is able to supply oxygen and nutrients, but current technology is unable to directly measure how well a placenta functions. Near-infrared spectroscopy (NIRS) utilizes optical methods to measure tissue oxygenation. This pilot project evaluated the feasibility of NIRS for fetal monitoring through the maternal abdominal wall using a sheep model. Methods: A miniature wireless 2-wavelength NIRS device was placed on the abdominal skin over the placenta of a pregnant ewe whose fetus had been chronically catheterized to allow arterial sampling for measurement of arterial oxygen saturation. The NIRS device has 3-paired light emitting diodes and a single photodiode detector; allowing measurement of an index of tissue oxygen saturation (TSI%). Fetal limb TSI% values were compared before and during fetal breathing movements. Correlation was made during these events between arterial values and placental TSI% monitored continuously in real time. Results: Serial measurements were obtained in a single experiment. The correlation between transcutaneous NIRS derived TSI% and direct arterial oxygen saturation was very high (R2=0.86). Measures of fetal limb TSI% were declined after episodes of fetal breathing (P<0.005). Conclusions: This correlation suggests that NIRS is sensitive enough to detect changes in fetal tissue oxygenation noninvasively through the maternal abdominal wall in real-time in a sheep model. NIRS data confirmed that fetal breathing movements decrease arterial oxygen saturation in fetal lambs. If validated by further study this optical methodology could be applied as means of monitoring fetal wellbeing in humans.

  15. A deep optical/near-infrared catalogue of Serpens

    NASA Astrophysics Data System (ADS)

    Spezzi, L.; Merín, B.; Oliveira, I.; van Dishoeck, E. F.; Brown, J. M.

    2010-04-01

    We present a deep optical/near-infrared imaging survey of the Serpens molecular cloud. This survey constitutes the complementary optical data to the Spitzer “Core To Disk” (c2d) Legacy survey in this cloud. The survey was conducted using the wide field camera at the Isaac Newton Telescope. About 0.96 square degrees were imaged in the R and Z filters, covering the entire region where most of the young stellar objects identified by the c2d survey are located. The 26 524 point-like sources were detected in both R and Z bands down to R ≈ 24.5 mag and Z ≈ 23 mag with a signal-to-noise ratio better than 3. The 95% completeness limit of our catalogue corresponds to 0.04 M⊙ for members of the Serpens star-forming region (age 2 Myr and distance 260 pc) in the absence of extinction. Adopting the typical extinction of the observed area (AV ≈ 7 mag), we estimate a 95% completeness level down to M ≈ 0.1 M_⊙. The astrometric accuracy of our catalogue is 0.4 arcsec with respect to the 2MASS catalogue. Our final catalogue contains J2000 celestial coordinates, magnitudes in the R and Z bands calibrated to the SDSS photometric system and, where possible, JHKS magnitudes from 2MASS for sources in 0.96 square degrees in the direction of Serpens. This data product has already been used within the frame of the c2d Spitzer Legacy Project analysis in Serpens to study the star/disk formation and evolution in this cloud. Here we use it to obtain new indications of the disk-less population in Serpens. Catalogue (in VizieR) is only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr/viz-bin/Cat

  16. Quantification of the extracerebral contamination of near infrared spectroscopy signals

    NASA Astrophysics Data System (ADS)

    Mudra, R.; Niederer, P.; Keller, E.

    2005-04-01

    Recently, conventional near infrared spectroscopy (NIRS) for oxymetry has been extended with an indocyanine green (ICG) dye dilution method which allows the estimation of cerebral blood flow (CBF) and cerebral blood volume (CBV). The signal obtained through the skull is substantially influenced by extracerebral tissue. In order to quantify and eliminate extracerebral contamination of the optical density signal we have applied two approaches. Firstly, we used spatially resolved spectroscopy (SRS) with a two receiver arrangement, with separations between emitter and two receivers in distances of d1=4.0cm and d2=6.5cm. The magnitude of the determined extracerebral contamination was verified with NIRS measurements in patients after brain herniation. Intracerebral circulatory arrest was confirmed by transcerebral Doppler examination. Secondly, Monte Carlo simulation was used to simulate the light propagation through the head to quantify the extracerebral contamination of the optical density signal of NIRS. The anatomical structure is determined from 3D-magnetic resonance imaging (MRI) using a voxel resolution of 0.8 x 0.8 x 0 .8 mm3 for three different pairs of T1/T2 values. We segment the MRI data to obtain a material matrix describing the composition of skin, skull, cerebral spinal fluid (CSF), grey and white matter. Each voxel in this material matrix characterizes the light absorption and dispersion coefficient of the identified material. This material matrix is applied in the Monte Carlo simulation. With SRS an extracerebral contamination of 65% of the optical density signal is extracted, while the Monte Carlo simulation results show that the extracerebral contamination decreases from 70% to 30% with increasing emitter-receiver distance. Differences between the NIRS ICG dye dilution technique and conventional NIRS oxymetry concerning the extracerebral contamination are discussed.

  17. The near-infrared spectrum of ethynyl radical

    NASA Astrophysics Data System (ADS)

    Le, Anh T.; Hall, Gregory E.; Sears, Trevor J.

    2016-08-01

    Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a 2Σ+ state at 6696 cm-1, a second 2Σ+ state at 7088 cm-1, and a 2Π state at 7110 cm-1. By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. The observed states contain both X2Σ+ and A2Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. The case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants.

  18. Effect of mechanical optical clearing on near-infrared spectroscopy.

    PubMed

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations.

  19. Effect of Mechanical Optical Clearing on Near-infrared Spectroscopy

    PubMed Central

    Idelson, Christopher R.; Vogt, William C.; King-Casas, Brooks; LaConte, Stephen M.; Rylander, Christopher G.

    2015-01-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5 fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations. PMID:26041069

  20. Sensitivity analysis of near-infrared functional lymphatic imaging

    NASA Astrophysics Data System (ADS)

    Weiler, Michael; Kassis, Timothy; Dixon, J. Brandon

    2012-03-01

    Background - Near-infrared (NIR) imaging of lymphatic drainage of injected indocyanine green (ICG) has emerged as a new technology for clinical imaging of lymphatic architecture and quantification of vessel function, offering better spatial and temporal resolution than competing imaging modalities. While NIR lymphatic imaging has begun to be reported in the literature, the technology is still in its infancy and its imaging capabilities have yet to be quantitatively characterized. The objective of this study, therefore, was to characterize the parameters of NIR lymphatic imaging to quantify its capabilities as a diagnostic tool for evaluating lymphatic disease. Methods - An NIR imaging system was developed using a laser diode for excitation, ICG as a fluorescent agent, and a CCD camera to detect emission. A tissue phantom with mock lymphatic vessels of known depths and diameters was used as an alternative to in vivo lymphatic vessels due to the greater degree of control with the phantom. Results and Conclusions - When dissolved in an albumin physiological salt solution (APSS) to mimic interstitial fluid, ICG experiences shifts in the excitation/emission wavelengths such that it is maximally excited at 805nm and produces peak fluorescence at 840nm. Premixing ICG with albumin induces greater fluorescence intensity, with the ideal concentration being: 900μM (60g/L) albumin and 193.5μM (150μg/mL) ICG. ICG fluorescence can be detected as deep as 6mm, but spatial resolution deteriorates severely below 3mm, thus skewing vessel geometry measurements. ICG packet travel, a common measure of lymphatic transport, can be detected as deep as 5mm.

  1. Near infrared photoimmunotherapy with an anti-mesothelin antibody

    PubMed Central

    Nagaya, Tadanobu; Nakamura, Yuko; Sato, Kazuhide; Zhang, Yi-Fan; Ni, Min; Choyke, Peter L.; Ho, Mitchell; Kobayashi, Hisataka

    2016-01-01

    Near Infrared-Photoimmunotherapy (NIR-PIT) is a new, highly selective tumor treatment that employs an antibody-photon absorber conjugate (APC). When the APC attaches to its target cell and is exposed to NIR light, highly selective cell killing is observed. NIR-PIT has been demonstrated with a limited number of antibodies. Mesothelin is overexpressed in several malignancies and is emerging as a therapeutic target. A recently humanized antibody (hYP218) has been generated against mesothelin that demonstrates high affinity binding. Here, we describe the efficacy of NIR-PIT, using hYP218 as the antibody within the APC to target a mesothelin expressing A431/H9 cell. The hYP218 antibody was conjugated to a photo-absorber, IR700 and incubated with the cells. The hYP218-IR700 showed specific binding to cells and cell-specific killing was observed in vitro. After implanting A431/H9 cells in an athymic nude mouse, tumor-bearing mice were treated with the following regimen of NIR-PIT; 100 μg of hYP218-IR700 i.v., NIR light was administered at 50 J/cm2 on day 1 after injection and 100 J/cm2 of light on day 2 after injection. The hYP218-IR700 showed high tumor accumulation and a high tumor-background ratio (TBR). Tumor growth was significantly inhibited by NIR-PIT treatment compared with the other control groups (p < 0.001), and significantly prolonged survival (p < 0.0001 vs other groups). Thus, the new anti-mesothelin antibody, hYP218, is suitable as an antibody-drug conjugate for NIR-PIT. Furthermore, NIR-PIT with hYP218-IR700 is a promising candidate for the treatment of mesothelin-expressing tumors that could be readily translated to humans. PMID:26981775

  2. The near-infrared spectrum of ethynyl radical

    DOE PAGES

    Le, Anh T.; Hall, Gregory E.; Sears, Trevor J.

    2016-08-17

    We used transient diode laser absorption spectroscopy to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a 2Σ+ state at 6696 cm-1,more » a second 2Σ+ state at 7088 cm-1, and a 2Π state at 7110 cm-1. By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. Moreover, the observed states contain both X 2Σ+ and A 2Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. Finally, the case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants.« less

  3. The near-infrared spectrum of ethynyl radical.

    PubMed

    Le, Anh T; Hall, Gregory E; Sears, Trevor J

    2016-08-21

    Transient diode laser absorption spectroscopy has been used to measure three strong vibronic bands in the near infrared spectrum of the C2H, ethynyl, radical not previously observed in the gas phase. The radical was produced by ultraviolet excimer laser photolysis of either acetylene or (1,1,1)-trifluoropropyne in a slowly flowing sample of the precursor diluted in inert gas, and the spectral resolution was Doppler-limited. The character of the upper states was determined from the rotational and fine structure in the observed spectra and assigned by measurement of ground state rotational combination differences. The upper states include a (2)Σ(+) state at 6696 cm(-1), a second (2)Σ(+) state at 7088 cm(-1), and a (2)Π state at 7110 cm(-1). By comparison with published calculations [R. Tarroni and S. Carter, J. Chem. Phys 119, 12878 (2003); Mol. Phys. 102, 2167 (2004)], the vibronic character of these levels was also assigned. The observed states contain both X(2)Σ(+) and A(2)Π electronic characters. Several local rotational level perturbations were observed in the excited states. Kinetic measurements of the time-evolution of the ground state populations following collisional relaxation and reactive loss of the radicals formed in a hot, non-thermal, population distribution were made using some of the strong rotational lines observed. The case of C2H may be a good place to investigate the behavior at intermediate pressures of inert colliders, where the competition between relaxation and reaction can be tuned and observed to compare with master equation models, rather than deliberately suppressed to measure thermal rate constants. PMID:27544104

  4. Augmented microscopy with near-infrared fluorescence detection

    NASA Astrophysics Data System (ADS)

    Watson, Jeffrey R.; Martirosyan, Nikolay; Skoch, Jesse; Lemole, G. Michael; Anton, Rein; Romanowski, Marek

    2015-03-01

    Near-infrared (NIR) fluorescence has become a frequently used intraoperative technique for image-guided surgical interventions. In procedures such as cerebral angiography, surgeons use the optical surgical microscope for the color view of the surgical field, and then switch to an electronic display for the NIR fluorescence images. However, the lack of stereoscopic, real-time, and on-site coregistration adds time and uncertainty to image-guided surgical procedures. To address these limitations, we developed the augmented microscope, whereby the electronically processed NIR fluorescence image is overlaid with the anatomical optical image in real-time within the optical path of the microscope. In vitro, the augmented microscope can detect and display indocyanine green (ICG) concentrations down to 94.5 nM, overlaid with the anatomical color image. We prepared polyacrylamide tissue phantoms with embedded polystyrene beads, yielding scattering properties similar to brain matter. In this model, 194 μM solution of ICG was detectable up to depths of 5 mm. ICG angiography was then performed in anesthetized rats. A dynamic process of ICG distribution in the vascular system overlaid with anatomical color images was observed and recorded. In summary, the augmented microscope demonstrates NIR fluorescence detection with superior real-time coregistration displayed within the ocular of the stereomicroscope. In comparison to other techniques, the augmented microscope retains full stereoscopic vision and optical controls including magnification and focus, camera capture, and multiuser access. Augmented microscopy may find application in surgeries where the use of traditional microscopes can be enhanced by contrast agents and image guided delivery of therapeutics, including oncology, neurosurgery, and ophthalmology.

  5. Raman Database Considerations for Near-Infrared Systems

    SciTech Connect

    Kunkel, Brenda M.; Su, Yin-Fong; Tonkyn, Russell G.; Stephan, Eric G.; Joly, Alan G.; Birnbaum, Jerome C.; Jarman, Kristin H.; Johnson, Timothy J.

    2011-12-21

    For Raman spectroscopy the ability to detect is often limited by the existence and quality of the reference library to which field spectra are compared. Developing such databases is often labor- and resource-intensive; typically the generated data are not transferred to other instruments. Still other considerations may exist for comparing data at visible and ultraviolet excitation wavelengths such as resonance enhancement. However, for the common near-infrared wavelengths of 785, 830, 960, 1047 and 1064 nm where this is normally of a lesser concern, it is logical to consider whether data can be ported from one spectrometer to another so as to obviate the expensive and time-consuming process of generating reference data for each system. The present experiment generated a list of 125 chemical and common substances and formed a database from their corresponding 1064 nm spectra. The same molecules were then measured using a 785 nm system the new spectra were treated as “unknowns” and compared to the 1064 nm database using a commercial search algorithm. We found that at least 108 of the 125 spectra recorded at 785 nm were correctly identified using the search algorithm. For the few that were incorrectly identified, in most cases the spectra were extremely similar or the 785 nm signal was degraded due to fluorescence, as would occur regardless of reference data. Our results indicate that if the spectrometers are properly calibrated on both their wavelength and intensity axes, “foreign” data recorded at a different NIR wavelength can be successfully used as reference libraries

  6. Near Infrared Imaging of Molecular Beacons in Cancers

    NASA Astrophysics Data System (ADS)

    Chance, Britton

    2001-03-01

    The recent demonstrations of the efficacy of the tumor to background contrast in breast cancer using the tricarbo-cyanine near infrared (NIR) agent with time domain 2-D imaging presages the greater efficacy of site-directed optical contrast agents for early detection of cancers which show contrast (tissue to background) of over 20 fold. Further increases of contrast are obtained with structures that quench the fluorescence until the agent is delivered, recognized, and opened by specific enzymatic activity of the tumor. These are termed ``Molecular Beacons". In order to image the localization of the Beacons, we employ light pen (< 40μ) scanning of the freeze trapped tumor in order to immobilize the tissue, to increase the fluorescence quantum yield and to limit the penetration of the excitation to a thin superficial layer (< 20μ). Precision milling of layers (> 20μ) in LN2 gives the desired 3D high resolution image of the location of the Beacon within in the cancer cell. Since cancer prevention is linked to early detection, the high signal to background obtainable with Molecular Beacons enables the detection of very early subsurface cancers, especially breast and prostate (NIH, UIP). Thus the fluorescent Beacon excites and emits in the NIR window and signals from several cm deep in breast are detected by diffusive wave optical tomography (DWOT). Detection of objects (< 1 mm) is achieved by phased array optical system using 0^O, 180^O 50 MHz modulation of pairs of laser diodes (780 nm) and fluorescence detection (> 800 nm) affording 0.2 mm object detection of even low Beacon concentrations. One, two, and 3-D localization is made possible by one, two, and three orthogonal phase array null planes.

  7. James Webb Telescope's Near Infrared Camera: Making Models, Building Understanding

    NASA Astrophysics Data System (ADS)

    Lebofsky, Larry A.; McCarthy, D. W.; Higgins, M. L.; Lebofsky, N. R.

    2010-10-01

    The Astronomy Camp for Girl Scout Leaders is a science education program sponsored by NASA's next large space telescope: The James Webb Space Telescope (JWST). The E/PO team for JWST's Near Infrared Camera (NIRCam), in collaboration with the Sahuaro Girl Scout Council, has developed a long-term relationship with adult leaders from all GSUSA Councils that directly benefits troops of all ages, not only in general science education but also specifically in the astronomical and technology concepts relating to JWST. We have been training and equipping these leaders so they can in turn teach young women essential concepts in astronomy, i.e., the night sky environment. We model what astronomers do by engaging trainers in the process of scientific inquiry, and we equip them to host troop-level astronomy-related activities. It is GSUSA's goal to foster girls’ interest and creativity in Science, Technology, Engineering, and Math, creating an environment that encourages their interests early in their lives while creating a safe place for girls to try and fail, and then try again and succeed. To date, we have trained over 158 leaders in 13 camps. These leaders have come from 24 states, DC, Guam, and Japan. While many of the camp activities are related to the "First Light” theme, many of the background activities relate to two of the other JWST and NIRCam themes: "Birth of Stars and Protoplanetary Systems” and "Planetary Systems and the Origin of Life.” The latter i