- ID:
- ivo://CDS.VizieR/III/188
- Title:
- IUE Atlas of B-Type Stellar Spectra
- Short Name:
- III/188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The IUE Atlas of B-type Stellar Spectra is an atlas of B-type spectra consisting of short-wavelength, high-resolution data from the International Ultraviolet Explorer archive, designed to complement the widely used O-star atlas from the same source (Walborn, Nichols-Bohlin, & Panek 1985, NASA Reference Publication 1155, catalog <III/115>). The atlas presented here completes the OB natural group, i.e., to spectral type B3 for the main sequence and giants, type B5 at class Ib, and B8 at Ia, which is also the most relevant domain for stellar-wind effects among normal B-type spectra.
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- ID:
- ivo://CDS.VizieR/III/115
- Title:
- IUE Atlas of O-Type Stellar Spectra
- Short Name:
- III/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The International Ultraviolet Explorer Atlas of O-Type Spectra From 1200 to 1900 A (Walborn et el. 1985) lists normalized fluxes and flux quality factors, splice points, and identifying information (star name/number, spectral type, SWP number, and name of the principal investigator) on 101 spectrograms of 98 O-type stars. The primary purpose of this work is to investigate the existence of systematic trends in the ultraviolet line spectra of the O stars, including the prominent stellar wind features, and the degree to which they correlate with the optical spectral classifications. A subsidiary objective is to identify ultraviolet features which may themselves prove useful as classifications criteria.
- ID:
- ivo://CDS.VizieR/J/ApJS/119/207
- Title:
- IUE echelle spectra of hot white dwarfs
- Short Name:
- J/ApJS/119/207
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper summarizes the results obtained from a comprehensive analysis of all of the SWP echelle spectra of the white dwarf stars contained in the IUE Final Archive. A total of 209 NEWSIPS spectra of 55 degenerate stars of various types have been systematically reduced and analyzed. These include, in addition to conventional white dwarfs, several examples of the hot planetary nebula central stars such as NGC 246, which represent the initial stages of He-rich degenerate evolution. A representative summary of the stellar, circumstellar, and interstellar features found to be present in these spectra is presented. For 33 of the 55 stars, multiple spectra of sufficient quality exist so that co-added spectra with improved signal-to-noise ratio can be constructed. Much previously unrecognized detail and many new features are evident in these data. In addition, it was found necessary to apply several corrections to the NEWSIPS extracted spectra. These corrections, involving the wavelength scale and flux uncertainty vector, are described.
- ID:
- ivo://CDS.VizieR/J/ApJS/147/145
- Title:
- IUE low-dispersion spectra of white dwarfs
- Short Name:
- J/ApJS/147/145
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have produced an archive of the ultraviolet low-dispersion spectra for the full set of white dwarf stars observed with the International Ultraviolet Explorer (IUE) satellite over the course of its 18-yr mission. This archive contains the spectra of 322 individual degenerate stars which have been processed to optimize the signal-to- noise for each star. In particular, all spectra have been corrected for residual temporal and thermal effects and placed on the Hubble Space Telescope Faint Object Spectrograph absolute flux scale using procedures described by Massa & Fitzpatrick (2000ApJS..126..517M). Wherever possible, multiple observations of individual stars have been co-added to further enhance signal-to-noise and have been combined into a single spectrum including the full 1150 to 3150{AA} wavelength region observed by IUE. The contents of this spectral archive are described and the details of data reduction procedures are provided. The electronic files of the processed spectra are available, in FITS and ASCII formats, with the associated log file, at http://vega.lpl.arizona.edu/newsips/low/
- ID:
- ivo://CDS.VizieR/J/A+AS/133/221
- Title:
- Library of ELODIE spectra (F5-K7 stars)
- Short Name:
- J/A+AS/133/221
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A library of 211 echelle spectra taken with ELODIE at the Observatoire de Haute-Provence is proposed. It provides a set of spectroscopic standards covering the full range of gravities and metallicities in the effective temperature interval [4000K, 6300K]. The spectra are straightened, wavelength calibrated, cleaned of cosmic ray hits, bad pixels and telluric lines. They cover the spectral range [440nm, 680nm] with an instrumental resolution of 42000. For each star, basic data were compiled from the Hipparcos catalogue (Cat. <I/239>) and the Hipparcos Input Catalogue (Cat. <I/196>) (Table 1). Radial velocities with a precision better than 100m/s are given. Atmospheric parameters Teff, logg, [Fe/H] from the literature are discussed. Because of scattered determinations in the bibliography, even for the most well-known stars, these parameters were adjusted by an iterative process which takes account of common or different spectral features between the standards, using our homogeneous set of spectra. Revised values of effective temperature, gravity and metallicity are proposed in Table 1. They are still consistent with the literature, and also lead to the self-consistency of the library, in the sense that similar spectra have similar atmospheric parameters. This adjustment was performed by using step by step a method based on the least square comparison of carefully prepared spectra, which was originally developed for the on-line estimation of the atmospheric parameters of faint field stars (Katz et al., 1998A&A...338..151K. Paper I.).
- ID:
- ivo://CDS.VizieR/J/AJ/155/104
- Title:
- MEGaSaURA. I. The sample and the spectra
- Short Name:
- J/AJ/155/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce Project MEGaSaURA: the Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas. MEGaSaURA comprises medium-resolution, rest-frame ultraviolet spectroscopy of N=15 bright gravitationally lensed galaxies at redshifts of 1.68<z<3.6, obtained with the MagE spectrograph on the Magellan telescopes. The spectra cover the observed-frame wavelength range 3200<{lambda}_o_<8280{AA}; the average spectral resolving power is R=3300. The median spectrum has a signal-to- noise ratio (S/N)=21 per resolution element at 5000{AA}. As such, the MEGaSaURA spectra have superior S/N and wavelength coverage compared to what COS/HST provides for starburst galaxies in the local universe. This paper describes the sample, the observations, and the data reduction. We compare the measured redshifts for the stars, the ionized gas as traced by nebular lines, and the neutral gas as traced by absorption lines; we find the expected bulk outflow of the neutral gas, and no systemic offset between the redshifts measured from nebular lines and the redshifts measured from the stellar continuum.
- ID:
- ivo://CDS.VizieR/J/A+A/617/A83
- Title:
- MIDI atlas of low- and intermediate-mass YSOs
- Short Name:
- J/A+A/617/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Protoplanetary disks show large diversity regarding their morphology and dust composition. With mid-infrared interferometry the thermal emission of disks can be spatially resolved, and the distribution and properties of the dust within can be studied. Our aim is to perform a statistical analysis on a large sample of 82 disks around low- and intermediate-mass young stars, based on mid-infrared interferometric observations. We intend to study the distribution of disk sizes, variability, and the silicate dust mineralogy. Archival mid-infrared interferometric data from the MIDI instrument on the Very Large Telescope Interferometer are homogeneously reduced and calibrated. Geometric disk models are used to fit the observations to get spatial information about the disks. An automatic spectral decomposition pipeline is applied to analyze the shape of the silicate feature. We present the resulting data products in the form of an atlas, containing N band correlated and total spectra, visibilities, and differential phases. The majority of our data can be well fitted with a continuous disk model, except for a few objects, where a gapped model gives a better match. From the mid-infrared size-luminosity relation we find that disks around T Tauri stars are generally colder and more extended with respect to the stellar luminosity than disks around Herbig Ae stars. We find that in the innermost part of the disks (r<~1au) the silicate feature is generally weaker than in the outer parts, suggesting that in the inner parts the dust is substantially more processed. We analyze stellar multiplicity and find that in two systems (AB Aur and HD 72106) data suggest a new companion or asymmetric inner disk structure. We make predictions for the observability of our objects with the upcoming Multi-AperTure mid- Infrared SpectroScopic Experiment (MATISSE) instrument, supporting the practical preparations of future MATISSE observations of T Tauri stars.
- ID:
- ivo://CDS.VizieR/J/ApJS/201/11
- Title:
- Mid-infrared spectral variability atlas of YSOs
- Short Name:
- J/ApJS/201/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The atlas presents medium-resolution mid-infrared spectra of low- and intermediate mass pre-main sequence objects obtained by the ISOPHOT-S spectrophotometer of the Infrared Space Observatory (ISO) and the Infrared Spectrograph (IRS) of the Spitzer Space Telescope.
- ID:
- ivo://CDS.VizieR/J/ApJS/190/147
- Title:
- Mid-IR galaxy morphology from S^4^G
- Short Name:
- J/ApJS/190/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spitzer Space Telescope Infrared Array Camera imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6um band, which is the best Spitzer waveband for galactic stellar mass morphology owing to its depth and its reddening-free sensitivity mainly to older stars. For this purpose, we have prepared classification images for 207 galaxies from the Spitzer archive, most of which are formally part of the Spitzer Survey of Stellar Structure in Galaxies (S^4^G), a Spitzer post-cryogenic ("warm") mission Exploration Science Legacy Program survey of 2331 galaxies closer than 40Mpc. For the purposes of morphology, the galaxies are interpreted as if the images are blue light, the historical waveband for classical galaxy classification studies. We find that 3.6um classifications are well correlated with blue-light classifications, to the point where the essential features of many galaxies look very similar in the two very different wavelength regimes. We present an atlas of all of the 207 galaxies analyzed here and bring attention to special features or galaxy types, such as nuclear rings, pseudobulges, flocculent spiral galaxies, I0 galaxies, double-stage and double-variety galaxies, and outer rings, that are particularly distinctive in the mid-IR.
- ID:
- ivo://CDS.VizieR/J/A+A/531/A165
- Title:
- MILES atmospheric parameters
- Short Name:
- J/A+A/531/A165
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Empirical libraries of stellar spectra are used to classify stars and synthetize stellar populations. MILES is a medium spectral-resolution library in the optical domain covering a wide range of temperatures, surface gravities and metallicities. We redetermine the atmospheric parameters of these stars in order to improve the homogeneity and accuracy. We build an interpolating function that returns a spectrum as a function of the three atmospheric parameters, and finally we characterize the precision of the wavelength calibration and stability of the spectral resolution. We used the ULySS program with the ELODIE library as a reference and compared the results with those in the literature. Results. We obtain precisions of 60K, 0.13, and 0.05dex, respectively, for Teff, logg, and [Fe/H] for the FGK stars. For the M stars, the mean errors are 38K, 0.26, and 0.12dex and 3.5%, 0.17, and 0.13dex for the OBA. We construct an interpolator that we test against the MILES stars themselves. We test it also by measuring the atmospheric parameters of the CFLIB stars with MILES as reference and find it to be more reliable than the ELODIE interpolator for the evolved hot stars, like those of the blue horizontal branch in particular.
