- ID:
- ivo://CDS.VizieR/J/ApJS/151/387
- Title:
- Near-IR spectral library of late-type stars
- Short Name:
- J/ApJS/151/387
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an empirical infrared spectral library of medium-resolution (R~2000-3000) H (1.6{mu}m) and K (2.2{mu}m) band spectra of 218 red stars, spanning a range of [Fe/H] from ~-2.2 to ~+0.3. The sample includes Galactic disk stars, bulge stars from Baade's window, and red giants from Galactic globular clusters. We report the values of 19 indices covering 12 spectral features measured from the spectra in the library. Finally, we derive calibrations to estimate the effective temperature, and diagnostic relationships to determine the luminosity classes of individual stars from near-infrared spectra. This paper is part of a larger effort aimed at building a near-IR spectral library to be incorporated in population synthesis models, as well as at testing synthetic stellar spectra.
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- 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.
- 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.
- 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).
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+A/551/A93
- Title:
- Nebular emission from z=~2-3 star-forming galaxies
- Short Name:
- J/A+A/551/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To investigate the ingredients, which allow star-forming galaxies to present Ly{alpha} line in emission, we studied the kinematics and gas phase metallicity of the interstellar medium. We used multi-object near-infrared spectroscopy with Magellan/MMIRS to study nebular emission from z=~2-3 star-forming galaxies discovered in three MUSYC fields.
- ID:
- ivo://CDS.VizieR/J/ApJ/755/90
- Title:
- [NeII] emission line observations from SgrA West
- Short Name:
- J/ApJ/755/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new observations of the [NeII] emission from the ionized gas in Sgr A West with improved resolution and sensitivity. About half of the emission comes from gas with kinematics indicating it is orbiting in a plane tipped about 25{deg} from the Galactic plane. This plane is consistent with that derived previously for the circumnuclear molecular disk and the northern arm and western arc ionized features. However, unlike most previous studies, we conclude that the ionized gas is not moving along the ionized features, but on more nearly circular paths. The observed speeds are close to, but probably somewhat less than expected for orbital motions in the potential of the central black hole and stars and have a small inward component. The spatial distribution of the emission is well fitted by a spiral pattern. We discuss possible physical explanations for the spatial distribution and kinematics of the ionized gas, and conclude that both may be best explained by a one-armed spiral density wave, which also accounts for both the observed low velocities and the inward velocity component. We suggest that a density wave may result from the precession of elliptical orbits in the potential of the black hole and stellar mass distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A110
- Title:
- Neutral gas in the Milky Way halo
- Short Name:
- J/A+A/542/A110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an absorption-selected survey of CaII and NaI features located in the halo of the Milky Way using QSO absorption spectroscopy. We made use of the ESO data archive and retrieved all publically available absorption-line data for low- and high-redshift QSOs observed with the Ultraviolet and Visual Echelle Spectrograph (UVES) on the VLT. This enormous data archive (Spectral Quasar Absorption Database, SQUAD; PI: M.T. Murphy) provides high-quality spectral data for ~400 quasars and active galactic nuclei (AGN). Most of these spectra were taken in the UVES standard configuration using the 1" slit, providing a spectral resolution of R~45000 (corresponding to a velocity resolution of ~6.6km/sFWHM). The spectral coverage as well as the signal-to-noise ratio (S/N) varies substantially among the spectra, reflecting the various scientific goals of the original proposals. For several of the sight lines we performed deep (brightness temperature limit, Tb_lim_~30mK, angular resolution: 9' FWHM, spectral resolution: 0.5km/s FWHM) follow-up radio observations using the Effelsberg 100-m telescope to search for HI emission. Furthermore for a large fraction of the sight lines we obtained HI data from the new Galactic All-Sky survey (GASS, Tb_lim_~60mK, angular resolution: 15.6' FWHM, spectral resolution: 0.8km/s FWHM) and the Effelsberg-Bonn HI survey (EBHIS, Tb_lim_~90mK, angular resolution: 10.5' FWHM, spectral resolution: 1.2km/s FWHM). All HI data were corrected for stray radiation using software by P. Kalberla.
- ID:
- ivo://CDS.VizieR/J/A+A/586/A125
- Title:
- Neutron-capture elements abundances in Cepheids
- Short Name:
- J/A+A/586/A125
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new accurate abundances for five neutron-capture (Y, La, Ce, Nd, Eu) elements in 73 classical Cepheids located across the Galactic thin disk. Individual abundances are based on high spectral resolution (R~38000) and high signal-to-noise ratio (S/N~50-300) spectra collected with UVES at ESO VLT for the DIONYSOS project. Taking account for similar Cepheid abundances provided either by our group (111 stars) or available in the literature, we end up with a sample of 435 Cepheids covering a broad range in iron abundances (-1.6<[Fe/H]<0.6). We found, using homogeneous individual distances and abundance scales, well defined gradients for the above elements. However, the slope of the light s-process element (Y) is at least a factor of two steeper than the slopes of heavy s- (La, Ce, Nd) and r- (Eu) process elements. The s to r abundance ratio ([La/Eu]) of Cepheids shows a well defined anticorrelation with of both Eu and Fe. On the other hand, Galactic field stars attain an almost constant value and only when they approach solar iron abundance display a mild enhancement in La. The [Y/Eu] ratio shows a mild evidence of a correlation with Eu and, in particular, with iron abundance for field Galactic stars. We also investigated the s-process index -- [hs/ls] -- and we found a well defined anticorrelation, as expected, between [La/Y] and iron abundance. Moreover, we found a strong correlation between [La/Y] and [La/Fe] and, in particular, a clear separation between Galactic and Sagittarius red giants. Finally, the comparison between predictions for low-mass asymptotic giant branch stars and the observed [La/Y] ratio indicate a very good agreement over the entire metallicity range covered by Cepheids. However, the observed spread, at fixed iron content, is larger than predicted by current models.
