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781. Near-IR spectra of extremely red AGB stars
ID:
ivo://CDS.VizieR/J/MNRAS/400/1413
Title:
Near-IR spectra of extremely red AGB stars
Short Name:
J/MNRAS/400/1413
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a library of 139 near-IR spectra of cool asymptotic giant branch stars that will be useful for comparison with theoretical model atmosphere calculations and for modelling the integrated emission from intermediate-age stellar populations. The source list was selected from the 'extremely red' region of the Isaac Newton Telescope (INT) Photometric H{alpha} Survey (IPHAS) colour-colour plane that is overwhelmingly dominated by very late-type stars. The spectral library also includes a large fraction of S-type and carbon stars. We present a number of spectral classification sequences highlighting the various molecular features identified and discuss a number of rare features with uncertain identifications in the literature. With its focus on particularly cool photospheres, this catalogue serves as a companion to recent spectroscopic atlases of MK standards in the near-IR. Finally, the relationship between IPHAS (r'-i') and (r'-H{alpha}) colours and spectroscopically determined properties is discussed and a strong correlation between the (r'-H{alpha}) colour and the C/O abundance index for S-type and carbon stars is noted. This relation has the potential to separate O-rich, S-type and carbon stars in the Galaxy based on their photometry alone.
782. Near-IR spectra of inner red giants
ID:
ivo://CDS.VizieR/J/A+A/479/131
Title:
Near-IR spectra of inner red giants
Short Name:
J/A+A/479/131
Date:
21 Oct 2021
Publisher:
CDS
Description:
The existence in the Milky Way of either a long thin bar with a half length of 4.5kpc and a position angle of around 45{deg} with respect to the Sun-Galactic centre line or a bulge+bar complex, thicker and shorter, with a smaller tilt respect to the Sun-GC line, has been a matter of discussion in recent decades. In this paper, we present low resolution (R=500) near-infrared spectra for selected and serendipitous sources in six inner in-plane Galactic fields at l=7{deg}, 12{deg}, 15{deg}, 20{deg}, 26{deg} and 27{deg}, with the aim of analysing the stellar content present in those fields.
783. Near-IR spectra of LMC globular clusters
ID:
ivo://CDS.VizieR/J/A+A/543/A75
Title:
Near-IR spectra of LMC globular clusters
Short Name:
J/A+A/543/A75
Date:
21 Oct 2021
Publisher:
CDS
Description:
The rest-frame near-IR spectra of intermediate age (1-2Gyr) stellar populations are dominated by carbon based absorption features offering a wealth of information. Yet, spectral libraries that include the near-IR wavelength range do not sample a sufficiently broad range of ages and metallicities to allow for accurate calibration of stellar population models and thus the interpretation of the observations. In this paper we investigate the integrated J- and H-band spectra of six intermediate age and old globular clusters in the Large Magellanic Cloud (LMC).
784. Near-IR spectroscopic survey of class I YSOs
ID:
ivo://CDS.VizieR/J/AJ/140/1214
Title:
Near-IR spectroscopic survey of class I YSOs
Short Name:
J/AJ/140/1214
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of a near-IR spectroscopic survey of 110 Class I protostars observed from 0.80um to 2.43um at a spectroscopic resolution of R=1200. This survey is unique in its selection of targets from the whole sky, its sample size, wavelength coverage, depth, and sample selection.
785. Near-IR spectroscopy follow-up of 60 SDSS-DR7 QSOs
ID:
ivo://CDS.VizieR/J/ApJ/753/125
Title:
Near-IR spectroscopy follow-up of 60 SDSS-DR7 QSOs
Short Name:
J/ApJ/753/125
Date:
21 Oct 2021
Publisher:
CDS
Description:
Single-epoch virial black hole (BH) mass estimators utilizing broad emission lines have been routinely applied to high-redshift quasars to estimate their BH masses. Depending on the redshift, different line estimators (H{alpha}, H{beta}, MgII{lambda}2798, CIV{lambda}1549) are often used with optical/near-infrared spectroscopy. Here, we use a homogeneous sample of 60 intermediate-redshift (z~1.5-2.2) Sloan Digital Sky Survey quasars with optical and near-infrared spectra covering CIV through H{alpha} to investigate the consistency between different single-epoch virial BH mass estimators.
786. Near-IR spectroscopy of low-mass binaries and brown dwarfs
ID:
ivo://CDS.VizieR/V/144
Title:
Near-IR spectroscopy of low-mass binaries and brown dwarfs
Short Name:
V/144
Date:
21 Oct 2021
Publisher:
CDS
Description:
The mass of a star at formation determines its subsequent evolution and demise. Low-mass stars are the most common products of star formation and their long main-sequence lifetimes cause them to accumulate over time. Star formation also produces many substellar-mass objects known as brown dwarfs, which emerge from their natal molecular clouds and continually cool as they age, pervading the Milky Way. Low-mass stars and brown dwarfs exhibit a wide range of physical characteristics and their abundance make them ideal subjects for testing formation and evolution models. I have examined a pair of pre-main sequence spectroscopic binaries and used radial velocity variations to determine orbital solutions and mass ratios. Additionally, I have employed synthetic spectra to estimate their effective temperatures and place them on theoretical Hertzsprung-Russell diagrams. From this analysis I discuss the formation and evolution of young binary systems and place bounds on absolute masses and radii. I have also studied the late-type T dwarfs revealed by the Wide-field Infrared Survey Explorer (WISE). This includes the exemplar T8 subdwarf Wolf 1130C, which has the lowest inferred metallicity in the literature and spectroscopic traits consistent with old age. Comparison to synthetic spectra implies that the dispersion in near-infrared colors of late-type T dwarfs is a result of age and/or thin sul de clouds. With the updated census of the L, T, and Y dwarfs we can now study specific brown dwarf subpopulations. Finally, I present a number of future studies that would develop our understanding of the physical qualities of T dwarf color outliers and disentangle the tracers of age and atmospheric properties. The thesis is available at: http://www.astro.ucla.edu/~gmace/thesis.html
787. Near-IR spectrum of HIP 109427 with SCExAO/CHARIS
ID:
ivo://CDS.VizieR/J/AJ/162/44
Title:
Near-IR spectrum of HIP 109427 with SCExAO/CHARIS
Short Name:
J/AJ/162/44
Date:
14 Mar 2022 06:55:09
Publisher:
CDS
Description:
We report the direct imaging discovery of a low-mass companion to the nearby accelerating A star, HIP109427, with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument coupled with the Microwave Kinetic Inductance Detector Exoplanet Camera (MEC) and CHARIS integral field spectrograph. CHARIS data reduced with reference star point spread function (PSF) subtraction yield 1.1-2.4{mu}m spectra. MEC reveals the companion in Y and J band at a comparable signal-to-noise ratio using stochastic speckle discrimination, with no PSF subtraction techniques. Combined with complementary follow-up Lp photometry from Keck/NIRC2, the SCExAO data favors a spectral type, effective temperature, and luminosity of M4-M5.5, 3000-3200K, and log_10_(L/L{odot})=-2.28_-0.04_^+0.04^, respectively. Relative astrometry of HIP109427B from SCExAO/CHARIS and Keck/NIRC2, and complementary Gaia-Hipparcos absolute astrometry of the primary favor a semimajor axis of 6.55+3.0-0.48au, an eccentricity of 0.54_-0.15_^+0.28^, an inclination of 66.7_-14_^+8.5^degrees, and a dynamical mass of 0.280_-0.059_^+0.18^M{sun}. This work shows the potential for extreme AO systems to utilize speckle statistics in addition to widely used postprocessing methods to directly image faint companions to nearby stars near the telescope diffraction limit.
788. Near-IR spectrum of 2M1207b
ID:
ivo://CDS.VizieR/J/A+A/517/A76
Title:
Near-IR spectrum of 2M1207b
Short Name:
J/A+A/517/A76
Date:
21 Oct 2021
Publisher:
CDS
Description:
Direct-imaging searches for planets reveal wide orbit planets amenable to spectroscopy, and their atmospheres represent an important comparison to the irradiated atmospheres of Hot Jupiters. Using AO integral field spectroscopy of 2M1207b, the shape of the continuum emission over the J, H, and K bands from the atmosphere of this young, planetary mass companion is measured in order to compare with atmospheric and evolutionary models, and objects of similar temperature in young clusters and the field. The 2M1207b spectrum has the highest spectral resolution (R~300-1500) and largest wavelength coverage, including the first J-band spectrum, for this benchmark object. The high signal-to-noise of the data allow a clear identification of signatures of low surface gravity, and comparison with a grid of AMES-Dusty models reveals a best-fit effective temperature of Teff=1600K with a preferred surface gravity of logg=4.5. The J-band flux is depressed relative to nearly all L-type objects, and the detailed shape of the absorption features across the H-band exhibit differences from the model predictions. The possible origins of 2M1207b and its low luminosity are examined with the new data and analysis which suggest that extinction from a disk with large grains is a viable scenario and is preferred over scattering off an optically thick disk. The 2M1207b spectrum presents an important comparison for the types of features which may be present in upcoming spectra of the atmospheres of planets imaged in orbit around stellar primaries.
789. Near-IR stellar spectra from 1.428 to 2.5 um
ID:
ivo://CDS.VizieR/III/196
Title:
Near-IR stellar spectra from 1.428 to 2.5 um
Short Name:
III/196
Date:
21 Oct 2021
Publisher:
CDS
Description:
This library is an EXTENDED VERSION of the library published by A.Lancon and B.Rocca-Volmerange in 1992. The catalog contains near-IR spectra of 84 stars, obtained with the Fourier Transform Spectrograph at the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii. The spectra cover the H and K atmospheric windows, i.e. wavelengths from 1.43 to 2.5 microns, with a typical resolving power of 500. The spectra have all been reduced again in 1996. The general procedure was as described in the original article, except that the intrinsic energy distributions of the stars used as references were assumed to be well represented by the models of Kurucz, 1993. Making extensive use of the Simbad data base, we have searched the literature on each of these stars, looking for effective temperature and extinction determinations. The new reduction improves the reliability of the continua, and reduces possible systematic differences between observing runs. The files contain the reduced spectra in FITS format, with fluxes in arbitrary units of energy per unit frequency (normalised to approximately 1 in the K band) and frequencies in cm^-1^, the natural units of Fourier Transform spectroscopy.
790. Near-IR survey of Northern PNs
ID:
ivo://CDS.VizieR/J/A+AS/104/169
Title:
Near-IR survey of Northern PNs
Short Name:
J/A+AS/104/169
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)