- ID:
- ivo://CDS.VizieR/J/A+A/540/A85
- Title:
- Spectroscopy of very low mass objects
- Short Name:
- J/A+A/540/A85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With a uniform VLT SINFONI data set of nine targets, we have developed an empirical grid of J, H, K spectra of the atmospheres of objects estimated to have very low substellar masses of ~5-20M_Jup_ and young ages ranging from ~1-50Myr. Most of the targets are companions, objects which are especially valuable for comparison with atmosphere and evolutionary models, as they present rare cases in which the age is accurately known from the primary. Based on the youth of the sample, all objects are expected to have low surface gravity, and this study investigates the critical early phases of the evolution of substellar objects. The spectra are compared with grids of five different theoretical atmosphere models. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/546/L3
- Title:
- Spectrum of LSR J0745+2627
- Short Name:
- J/A+A/546/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo population. LSR J0745+2627 has a high proper motion (890mas/yr) and a high reduced proper motion value in the J band (H_J=21.87). We show how the infrared-reduced proper motion diagram is useful for selecting a sample of cool white dwarfs with low contamination. LSR J0745+2627 is also detected in the Sloan Digital Sky Survey (SDSS) and the Wide-field Infrared Survey Explorer (WISE). We have spectroscopically confirmed this object as a cool white dwarf using X-Shooter on the Very Large Telescope. An analysis of its spectral energy distribution reveals that its atmosphere is compatible with a pure-H composition model with an effective temperature of 3880+/-90K. This object is the brightest pure-H ultracool white dwarf (Teff<4000K) ever identified. We have constrained the distance (24-45pc), space velocities and age considering different surface gravities. The results obtained suggest that LSR J0745+2627 belongs to the thick-disk/halo population and is also one of the closest ultracool white dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/16
- Title:
- SpeX NIR survey of 886 nearby M dwarfs
- Short Name:
- J/ApJS/220/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of near-infrared (NIR) spectra and associated measurements for 886 nearby M dwarfs. The spectra were obtained with the NASA-Infrared Telescope Facility SpeX Spectrograph during a two-year observing campaign; they have high signal-to-noise ratios (S/N>100-150), span 0.8-2.4{mu}m, and have R~2000. Our catalog of measured values contains useful T_eff_ and composition-sensitive features, empirical stellar parameter measurements, and kinematic, photometric, and astrometric properties compiled from the literature. We focus on measurements of M dwarf abundances ([Fe/H] and [M/H]), capitalizing on the precision of recently published empirical NIR spectroscopic calibrations. We explore systematic differences between different abundance calibrations, and from other similar M dwarf catalogs. We confirm that the M dwarf abundances we measure show the expected inverse dependence with kinematic-, activity-, and color-based age indicators. Finally, we provide updated [Fe/H] and [M/H] for 16 M dwarf planet hosts. This catalog represents the largest published compilation of NIR spectra and associated parameters for M dwarfs. It provides a rich and uniform resource for nearby M dwarfs, and will be especially valuable for measuring Habitable Zone locations and comparative abundances of the M dwarf planet hosts that will be uncovered by upcoming exoplanet surveys.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/1142
- Title:
- SpeX spectroscopy of low mass binaries. I.
- Short Name:
- J/ApJ/710/1142
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the identification of 17 candidate brown dwarf binaries whose components straddle the L dwarf/T dwarf transition. These sources were culled from a large near-infrared spectral sample of L and T dwarfs observed with the Infrared Telescope Facility SpeX spectrograph. Candidates were selected on the basis of spectral ratios which segregate known (resolved) L dwarf/T dwarf pairs from presumably single sources. Composite templates, constructed by combining 13581 pairs of absolute flux-calibrated spectra, are shown to provide statistically superior fits to the spectra of our 17 candidates as compared to single templates. Ten of these candidates appear to have secondary components that are significantly brighter than their primaries over the 1.0-1.3um band, indicative of rapid condensate depletion at the L dwarf/T dwarf transition. Our results support prior indications of enhanced multiplicity amongst early-type T dwarfs; 53+/-7% of the T0-T4 dwarfs in our spectral sample are found to be either resolved or unresolved (candidate) pairs, although this is consistent with an intrinsic (volume complete) brown dwarf binary fraction of only 15%. If verified, this sample of spectral binaries more than doubles the number of known L dwarf/T dwarf transition pairs, enabling a broader exploration of this poorly understood phase of brown dwarf atmospheric evolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/877/110
- Title:
- SPIRITS catalog of IR long period variables
- Short Name:
- J/ApJ/877/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 417 luminous infrared variable stars with periods exceeding 250 days. These were identified in 20 nearby galaxies by the ongoing SPitzer InfraRed Intensive Transients Survey survey with the Spitzer Space Telescope. Of these, 359 variables have M_[4.5]_ (phase-weighted mean magnitudes) fainter than -12 and periods and luminosities consistent with previously reported variables in the Large Magellanic Cloud (LMC). However, 58 variables are more luminous than M_[4.5]_=-12, including 11 that are brighter than M_[4.5]_=-13, with the brightest having M_[4.5]_=-15.51. Most of these bright variable sources have quasi-periods longer than 1000 days, including four over 2000 days. We suggest that the fundamental period-luminosity relationship, previously measured for the LMC, extends to much higher luminosities and longer periods in this large galaxy sample. We posit that these variables include massive asymptotic giant branch (AGB) stars (possibly super-AGB stars), red supergiants experiencing exceptionally high mass-loss rates, and interacting binaries. We also present 3.6, 4.5, 5.8, and 8.0{mu}m photometric catalogs for all sources in these 20 galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/685/958
- Title:
- Spitzer and Chandra sources in galactic center
- Short Name:
- J/ApJ/685/958
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have studied the correlation between 2357 Chandra X-ray point sources in a 40x40pc field and ~20000 infrared sources we observed in the corresponding subset of our 2x1.4{deg} Spitzer/IRAC Galactic Center Survey at 3.6-8.0um, using various spatial and X-ray hardness thresholds. The correlation was determined for source separations of less than 0.5", 1", or 2". Only the soft X-ray sources show any correlation with infrared point sources on these scales, and that correlation is very weak. The upper limit on hard X-ray sources that have infrared counterparts is <1.7% (3{sigma}). However, because of the confusion limit of the IR catalog, we only detect IR sources with absolute magnitudes <~1. As a result, a stronger correlation with fainter sources cannot be ruled out. Only one compact IR source, IRS 13, coincides with any of the dozen prominent X-ray emission features in the 3x3pc region centered on Sgr A*, and the diffuse X-ray and IR emission around Sgr A* seems to be anticorrelated on a few-arcsecond scale. We compare our results with previous identifications of near-infrared companions to Chandra X-ray sources.
- ID:
- ivo://CDS.VizieR/J/ApJS/191/301
- Title:
- Spitzer Atlas of Stellar Spectra (SASS)
- Short Name:
- J/ApJS/191/301
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Spitzer Atlas of Stellar Spectra (SASS) includes 159 stellar spectra (5 to 32um; R~100) taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope. It gathers representative spectra of a broad section of the Hertzsprung-Russell diagram, intended to serve as a general stellar spectral reference in the mid-infrared. It includes stars from all luminosity classes, as well as Wolf-Rayet (WR) objects. Furthermore, it includes some objects of intrinsic interest, like blue stragglers and certain pulsating variables. All the spectra have been uniformly reduced.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/SEIP/IRAC_Cov
- Title:
- Spitzer Enhanced Imaging Products IRAC Coverage Table
- Short Name:
- SEIP IRAC Cov
- Date:
- 01 Oct 2018 20:27:16
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Science Center (SSC) and Infrared Science Archive (IRSA) have released a set of Enhanced Imaging Products from the Spitzer Heritage Archive. These include enhanced mosaic images created from multiple AORs where appropriate and a source list (SL) of photometry for compact sources. The enhanced imaging products include data from the four channels of IRAC (3-8 microns) and the 24 micron channel of MIPS. The Source List was designed to prioritize reliability over completeness. In order to make the Source List reliable, many sources were rejected. Therefore, it is not complete at any flux density. At bright flux densities, nearby galaxies may be rejected for being too extended, or for being too close to a neighboring galaxy. At faint flux densities, sources will be missing because they do not meet the signal-to-noise cut. Although the Source List is useful for many science projects, users who require high levels of completeness are encouraged to use caution. If you are interested in a source that does not appear in the Source List, you should first inspect the Coverage Table to ensure that the data exists, and then consider measuring the photometry on the Super Mosaics yourself.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/SEIP/MIPS_Cov
- Title:
- Spitzer Enhanced Imaging Products MIPS Coverage Table
- Short Name:
- SEIP MIPS Cov
- Date:
- 01 Oct 2018 20:27:16
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Science Center (SSC) and Infrared Science Archive (IRSA) have released a set of Enhanced Imaging Products from the Spitzer Heritage Archive. These include enhanced mosaic images created from multiple AORs where appropriate and a source list (SL) of photometry for compact sources. The enhanced imaging products include data from the four channels of IRAC (3-8 microns) and the 24 micron channel of MIPS. The Source List was designed to prioritize reliability over completeness. In order to make the Source List reliable, many sources were rejected. Therefore, it is not complete at any flux density. At bright flux densities, nearby galaxies may be rejected for being too extended, or for being too close to a neighboring galaxy. At faint flux densities, sources will be missing because they do not meet the signal-to-noise cut. Although the Source List is useful for many science projects, users who require high levels of completeness are encouraged to use caution. If you are interested in a source that does not appear in the Source List, you should first inspect the Coverage Table to ensure that the data exists, and then consider measuring the photometry on the Super Mosaics yourself.
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/SEIP/SourceList
- Title:
- Spitzer Enhanced Imaging Products Source List
- Short Name:
- SEIP
- Date:
- 01 Oct 2018 20:27:16
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Science Center and IRSA have released a set of Enhanced Imaging Products (SEIP) from the Spitzer Heritage Archive. These include Super Mosaics (combining data from multiple programs where appropriate) and a Source List of photometry for compact sources. The primary requirement on the Source List is very high reliability -- with areal coverage, completeness, and limiting depth being secondary considerations. The SEIP include data from the four channels of IRAC (3.6, 4.5, 5.8, 8 microns) and the 24 micron channel of MIPS. The full set of products for the Spitzer cryogenic mission includes around 42 million sources.
