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1851. Normalized spectra of 82 Kepler red giants
ID:
ivo://CDS.VizieR/J/A+A/543/A160
Title:
Normalized spectra of 82 Kepler red giants
Short Name:
J/A+A/543/A160
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. We aim at determining accurate atmospheric parameters and the abundance pattern for a sample of 82 red giants that are targets for the Kepler mission. We have used high-resolution, high signal-to-noise spectra from three different spectrographs. We used the iterative spectral synthesis method VWA to derive the fundamental parameters from carefully selected high-quality iron lines. After determination of the fundamental parameters, abundances of 13 elements were measured using equivalent widths of the spectral lines. Results: We identify discrepancies in logg and [Fe/H], compared to the parameters based on photometric indices in the Kepler Input Catalogue, Cat. V/133 (larger than 2.0dex for logg and [Fe/H] for individual stars). The Teff found from spectroscopy and photometry shows good agreement within the uncertainties. We find good agreement between the spectroscopic logg and the logg derived from asteroseismology. Also, we see indications of a potential metallicity effect on the stellar oscillations. We have determined the fundamental parameters and element abundances of 82 red giants. The large discrepancies between the spectroscopic logg and [Fe/H] and values in the Kepler Input Catalogue emphasize the need for further detailed spectroscopic follow-up of the Kepler targets in order to produce reliable results from the asteroseismic analysis.
1852. Normalized spectra of 20 red giants
ID:
ivo://CDS.VizieR/J/A+A/528/A121
Title:
Normalized spectra of 20 red giants
Short Name:
J/A+A/528/A121
Date:
21 Oct 2021
Publisher:
CDS
Description:
Accurate fundamental parameters of stars are mandatory for the asteroseismic investigation of the Kepler mission to succeed. We determine the atmospheric parameters for a sample of six well-studied bright K giants to confirm that our method produces reliable results. We then apply the same method to 14 K giants that are targets of the Kepler mission.
1853. Northern HI Parkes All Sky Survey Catalogue (HIPASS)
ID:
ivo://CDS.VizieR/VIII/89
Title:
Northern HI Parkes All Sky Survey Catalogue (HIPASS)
Short Name:
VIII/89
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Northern HIPASS catalogue (NHICAT) is the northern extension of the HIPASS catalogue, HICAT. This extension adds the sky area between the declination (Dec.) range of +2{deg}<DE<+25{deg}30' to HICAT's Dec. range of -90{deg}<DE<+2{deg}. HIPASS is a blind HI survey using the Parkes Radio Telescope covering 71 per cent of the sky (including this northern extension) and a heliocentric velocity range of -1280 to 12700km/s. The entire Virgo Cluster region has been observed in the Northern HIPASS. The galaxy catalogue, NHICAT, contains 1002 sources with v_hel_>300km/s. Sources with -300<v_hel_<300km/s were excluded to avoid contamination by Galactic emission. In total, the entire HIPASS survey has found 5317 galaxies identified purely by their HI content. The full galaxy catalogue is publicly available at http://hipass.aus-vo.org.
1854. NOT GL survey of multiply imaged quasars
ID:
ivo://CDS.VizieR/J/A+A/300/323
Title:
NOT GL survey of multiply imaged quasars
Short Name:
J/A+A/300/323
Date:
21 Oct 2021
Publisher:
CDS
Description:
A gravitational lens (GL)-search program, initiated in 1990 at the Nordic Optcal Telescope (NOT), has revealed several possible GL-candidates among a sample of 168 quasars (QSOs), chosen from three lists compiled by C. Hazard, D. Reimers and J. Surdej, respectively. Some of these candidates, selected for having close companions (within 5 arcseconds), were imaged in several filters and their colours compared. Low dispersion spectra of the most promising candidates were also obtained at the NOT and ESO New Technology Telescope (NTT). None of these has proved to be strong candidates of gravitational lensing effects. We present this new sample of QSOs and combine it with previously published optical QSO samples in a statistical analysis to yield constraints on flat cosmologies and galaxy velocity dispersions.
1855. N-rich field stars from LAMOST and APOGEE data
ID:
ivo://CDS.VizieR/J/ApJ/891/28
Title:
N-rich field stars from LAMOST and APOGEE data
Short Name:
J/ApJ/891/28
Date:
21 Oct 2021
Publisher:
CDS
Description:
Interesting chemically peculiar field stars may reflect their stellar evolution history and their possible origin in a different environment from where they are found now; this is one of the most important research fields in Galactic archeology. To explore this further, we have used the CN-CH bands around 4000{AA} to identify N-rich metal-poor field stars in LAMOST DR3. Here we expand our N-rich, metal-poor field star sample to ~100 stars in LAMOST DR5, where 53 of them are newly found in this work. We investigate light elements of common stars between our sample and APOGEE DR14. While Mg, Al, and Si abundances generally agree with the hypothesis that N-rich metal-poor field stars come from enriched populations in globular clusters, it is still inconclusive for C, N, and O. After integrating the orbits of our N-rich field stars and a control sample of normal metal-poor field stars, we find that N-rich field stars have different orbital parameter distributions compared to the control sample-specifically, apocentric distances, maximum vertical amplitude (Zmax), orbital energy, and z-direction angular momentum (Lz). The orbital parameters of N-rich field stars indicate that most of them are inner-halo stars. The kinematics of N-rich field stars support their possible GC origin. The spatial and velocity distributions of our bona fide N-rich field star sample are important observational evidence to constrain simulations of the origin of these interesting objects.
1856. Number counts predictions for surveys
ID:
ivo://CDS.VizieR/J/MNRAS/472/4878
Title:
Number counts predictions for surveys
Short Name:
J/MNRAS/472/4878
Date:
21 Oct 2021
Publisher:
CDS
Description:
We estimate the number counts of line emitters at high redshift and their evolution with cosmic time based on a combination of photometry and spectroscopy. We predict the H{alpha}, H{beta}, [OII], and [OIII] line fluxes for more than 35000 galaxies down to stellar masses of ~10^9^M_{sun}_ in the COSMOS and GOODS-S fields, applying standard conversions and exploiting the spectroscopic coverage of the FMOS-COSMOS survey at z~1.55 to calibrate the predictions. We calculate the number counts of H{alpha}, [OII], and [OIII] emitters down to fluxes of 1x10^-17^erg/cm^2^/s in the range 1.4<z<1.8 covered by the FMOS-COSMOS survey. We model the time evolution of the differential and cumulative H{alpha} counts, steeply declining at the brightest fluxes. We expect ~9300-9700 and ~2300-2900-galaxies/deg^2^ for fluxes >=1x10^-16^ and >=2x10^-16^erg/cm^2^/s over the range of 0.9<z<1.8. We show that the observed evolution of the main sequence of galaxies with redshift is enough to reproduce the observed counts variation at 0.2<z<2.5. We characterize the physical properties of the H{alpha} emitters with fluxes >=2x10^-16^erg/cm^2^/s including their stellar masses, UV sizes, [NII]/H{alpha} ratios and H{alpha} equivalent widths. An aperture of R~R_e_~0.5arcsec maximizes the signal-to-noise ratio for a detection, whilst causing a factor of ~2x flux losses, influencing the recoverable number counts, if neglected. Our approach, based on deep and large photometric data sets, reduces the uncertainties on the number counts due to the selection and spectroscopic samplings whilst exploring low fluxes. We publicly release the line flux predictions for the explored photometric samples.
1857. NuSTAR serendipitous survey: the 40-month catalog
ID:
ivo://CDS.VizieR/J/ApJ/836/99
Title:
NuSTAR serendipitous survey: the 40-month catalog
Short Name:
J/ApJ/836/99
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20Ms of effective exposure time over 331 fields, with an areal coverage of 13deg^2^, and 497 sources detected in total over the 3-24keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from our extensive campaign of ground-based spectroscopic follow-up. We characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGNs), detected over a large range in redshift from z=0.002 to 3.4 (median of <z>=0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from log(f_3-24keV_/erg/s/cm^2^)~-14 to -11, and in rest-frame 10-40keV luminosity, from log(L_10-40keV_/erg/s)~39 to 46, with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ~15% at the highest luminosities (L_X_>10^44^erg/s) to ~80% at the lowest luminosities (L_X_<10^43^erg/s). Our optical spectroscopic analysis finds that the observed fraction of optically obscured AGNs (i.e., the type 2 fraction) is F_Type2_=53_-15_^+14^% , for a well-defined subset of the 8-24keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by <10keV X-ray missions.
1858. NUV spectrum of eta Car in 2003.5
ID:
ivo://CDS.VizieR/J/ApJS/168/289
Title:
NUV spectrum of eta Car in 2003.5
Short Name:
J/ApJS/168/289
Date:
21 Oct 2021
Publisher:
CDS
Description:
Hubble Space Telescope Space Telescope Imaging Spectrograph (HST STIS) near-ultraviolet (NUV) echelle spectra reveal complex structure in the sight line toward the Weigelt D condensation located 0.25" north-northwest of {eta} Car. This analysis uses data recorded between 2000 October and 2004 March to monitor changes in emission and absorption as the UV photoexciting fluxes from {eta} Car drop and later reappear. We compare changes in the wind profiles seen against the star and the CS absorptions to gain knowledge of the properties of the extended wind and the ejecta. Complete spectra, in the wavelength region 2424-2706{AA}, with line identifications are available in the electronic edition of this paper.
1859. O and B type stars in W3: first results
ID:
ivo://CDS.VizieR/J/ApJ/813/42
Title:
O and B type stars in W3: first results
Short Name:
J/ApJ/813/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the first results from our survey of the star-forming complex W3, combining VRI photometry with multiobject spectroscopy to identify and characterize the high-mass stellar population across the region. With 79 new spectral classifications, we bring the total number of spectroscopically confirmed O- and B-type stars in W3 to 105. We find that the high-mass slope of the mass function in W3 is consistent with a Salpeter IMF, and that the extinction toward the region is best characterized by an R_V_ of approximately 3.6. B-type stars are found to be more widely dispersed across the W3 giant molecular cloud (GMC) than previously realized: they are not confined to the high-density layer (HDL) created by the expansion of the neighboring W4 H ii region into the GMC. This broader B-type population suggests that star formation in W3 began spontaneously up to 8-10 Myr ago, although at a lower level than the more recent star formation episodes in the HDL. In addition, we describe a method of optimizing sky subtraction for fiber spectra in regions of strong and spatially variable nebular emission.
1860. O, B and Be stars equivalent widths
ID:
ivo://CDS.VizieR/J/A+A/384/473
Title:
O, B and Be stars equivalent widths
Short Name:
J/A+A/384/473
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an atlas of spectra of O- and B-type stars, obtained with the Short Wavelength Spectrometer (SWS) during the Post-Helium program of the Infrared Space Observatory (ISO). This program is aimed at extending the Morgan & Keenan (1973ARA&A..11...29M) classification scheme into the near-infrared. Later type stars will be discussed in a separate publication. The observations consist of 57 SWS Post-Helium spectra from 2.4 to 4.1{mu}m, supplemented with 10 spectra acquired during the nominal mission with a similar observational setting. For B-type stars, this sample provides ample spectral coverage in terms of subtype and luminosity class. For O-type stars, the ISO sample is coarse and therefore is complemented with 8 UKIRT L'-band observations. In terms of the presence of diagnostic lines, the L'-band is likely the most promising of the near-infrared atmospheric windows for the study of the physical properties of B stars. Specifically, this wavelength interval contains the Br{alpha}, Pf{gamma}, and other Pfund lines which are probes of spectral type, luminosity class and mass loss. Here, we present simple empirical methods based on the lines present in the 2.4 to 4.1{mu}m interval that allow the determination of i) the spectral type of B dwarfs and giants to within two subtypes; ii) the luminosity class of B stars to within two classes; iii) the mass-loss rate of O stars and B supergiants to within 0.25dex.

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