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- ID:
- ivo://CDS.VizieR/III/280
- Title:
- Astron low resolution UV spectra
- Short Name:
- III/280
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astron was a Soviet spacecraft launched on 23 March 1983, and it was operational for eight years as the largest ultraviolet space telescope during its lifetime. Astron's payload consisted of an 80 cm ultraviolet telescope Spica and an X-ray spectroscope. We present 159 low resolution spectra of stars obtained during the Astron space mission (Tables 4, 5; hereafter table numbers in Boyarchuk et al. 1994 are given). Table 4 (observational log, logs.dat) contains data on 142 sessions for 90 stars (sorted in ascending order of RA), where SED was obtained by scanning method, and then data on 17 sessions for 15 stars (also sorted in ascending order of RA), where multicolor photometry was done. Kilpio et al. (2016, Baltic Astronomy 25, 23) presented results of the comparison of Astron data to the modern UV stellar data, discussed Astron precision and accuracy, and made some conclusions on potential application areas of these data. Also 34 sessions of observations of 27 stellar systems (galaxies and globular clusters) are presented. Observational log was published in Table 10 and data were published in Table 11, respectively. Also 16 sessions of observations of 12 nebulae (Table 12 for observational log and Table 13 for data themselves) are presented. Background radiation intensity data (Table 14) are presented in Table 15. At last, data on comets are presented in different forms. We draw your attention that observational data for stars, stellar systems, nebulae and comets are expressed in log [erg/s/cm^2/A], while for comets data 10E-13 erg/s/cm^2/A units are used, hydroxyl band photometric data for comets are expressed in log [erg/s/cm^2], and for the background data it is radiation intensity expressed in log [erg/s/cm^2/A/sr]. Scanned (PDF version of) Boyarchuk et al. (1994) book is available at http://www.inasan.ru/~astron/astron.pdf
- ID:
- ivo://CDS.VizieR/J/A+AS/137/351
- Title:
- A supergiants UV and visible spectra
- Short Name:
- J/A+AS/137/351
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the first of a series whose aim is to perform a systematic study of A-type supergiant atmospheres and winds. Here we present a spectral atlas of 41 A-supergiants observed by us in high and medium resolution in the visible and ultraviolet. The atlas consists of profiles of the H{alpha}, H{beta}, H{gamma}, H{delta}, H{epsilon}, Ca II (H and K), Na I (D1 and D2), Mg II_4481_, Mg II [uv1] and Fe II [uv1, uv2, uv3, uv62, uv63, uv161] lines for 41 stars with spectral types ranging from B9 to A9 and luminosity classes Ia, Iab and Ib, and provides the basic data for a thoughtful study of these stars. The overall characteristics of the sample as well as the data reduction procedures are described. We also present some examples of spectral variability.
- ID:
- ivo://CDS.VizieR/J/A+A/397/1035
- Title:
- Atlas of B6-A2 hyper- and supergiants
- Short Name:
- J/A+A/397/1035
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of spectra of 5 emission-line stars: the low-luminosity luminous blue variables (LBVs) HD 168625 and HD 160529, the white hypergiants (and LBV candidates) HD 168607 and AS 314, and the supergiant HD 183143. The spectra were obtained with 2 echelle spectrometers at the 6-m telescope of the Russian Academy of Sciences in the spectral range 4800 to 6700{AA}, with a resolution of 0.4{AA}. We have identified 380 spectral lines and diffuse interstellar bands within the spectra. Specific spectral features of the objects are described.
- ID:
- ivo://CDS.VizieR/VIII/54
- Title:
- Atlas of Galactic Neutral Hydrogen
- Short Name:
- VIII/54
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Leiden/Dwingeloo HI survey mapped the 21-cm spectral line emission over the entire sky above declinations of -30 degrees using a grid spacing of ~ 0.5 degree and a velocity sampling of ~ 1.03 km/s. The useful velocity (V_lsr) range is from -450 to +400 km/s. The Atlas presents calibrated spectra in units of brightness temperature. Using interpolation and averaging, the authors have placed their data on an evenly-spaced grid in Galactic coordinates (l,b). A detailed discussion of the instrument and calibration procedures is provided in the published Atlas. The average sensitivity level of the survey is 0.07 K (1-sigma, rms). This sensitivity level depends critically on the success of the stray-radiation correction as discussed in Hartmann et al. (1996A&AS..119..115H). In that discussion, several caveats are offered regarding the removal of stray radiation, in particular that component which might be due to reflection from the ground. Some instances have been found where there are residuals which are clearly larger than the mean accuracy quoted as representative of the Leiden/Dwingeloo survey. Users of the data are reminded that the stray-radiation correction was applied conservatively, ensuring that no overestimate was calculated and removed, thereby yielding spurious negative intensities. A specific example of remaining spurious emission is evident towards the North Galactic Pole, a direction notoriously difficult to observe. All spectra taken towards b=+90 degrees should, of course, be identical, no matter the longitude or the orientation of the telescope with respect to the ground or to the meridian. Because the sky was sampled in 5x5 degree boxes, a spectrum was recorded at b=+90 degrees for every Nx5 degrees (N=0..72) in longitude. The spectra in the final dataset were interpolated between these measured spectra to yield a 0.5x0.5 degree grid. So, only every 10th spectrum at this extreme latitude corresponds to an observed spectrum. Comparing all spectra at b=+90 reveals differences which are larger than expected. The origin of this discrepancy is currently unknown. There is also an instrumental effect which reveals itself as correlated noise, showing a pattern which alternates sign at adjacent channels when the very lowest levels of intensity are examined. This effect is due to an offset in the DAS autocorrelator used as the backend in the Leiden/Dwingeloo survey. The presence of this artifact becomes noticeable only after averaging 50 or more spectra. Although a Hanning convolution of the data would eliminate this effect, it would also degrade the velocity resolution; as the correlated noise is noticeable only at very low levels (about 15 mK), well below the mean rms sensitivity of the survey itself, the original spectra have not been Hanning smoothed. Excepted are those spectra which suffered from sinc interference. These spectra were Hanning smoothed to enable the elimination of the interference spike. Dr. Lloyd Higgs has compared the HI spectra made with the DRAO 26-m telescope in support of the Canadian Galactic Plane Survey with those of the Leiden Dwingeloo Survey, and has pointed out what are evidently calibration problems in a small number of isolated LDS spectra. Either Hartmann, Burton, or Higgs could provide additional information. The Leiden/Dwingeloo HI survey is intended primarily for studies of the interstellar gas associated with our own Galaxy. There are, however, a small number of spectra in which 'contaminating' signatures from known external galaxies are present. Detections of roughly 50 such external galaxies were made; refer to table 4 of the Atlas for a list. The HI spectra from the Leiden/Dwingeloo survey are archived as 721 files. Each file is in FITS image format, and maps the 21-cm brightness temperature at a fixed Galactic longitude for an evenly-spaced rectangular grid of (Galactic latitude, velocity) points. There is one FITS file for every 0.5 degree in Galactic longitude in the "fits" subdirectory. In addition to the 721 (b,v) FITS files, there is an (l,b) FITS image named TOTAL_HI.FIT, which contains the integrated intensity map over the velocity range -450 km/s <= V_lsr <= +400 km/s. The map units are in [K.km/s] and the FITS header contains comments regarding the conversion to column densities. Included as a visual aid is the GIF image file total_hi.gif, which depicts the velocity-integrated map. The data were originally distributed on a CD-ROM enclosed with the Atlas of Galactic Neutral Hydrogen (reference given above). The CD also contains animations of velocity slices through the data cube.
- ID:
- ivo://CDS.VizieR/VII/74A
- Title:
- Atlas of Peculiar Galaxies
- Short Name:
- VII/74A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This electronic version of Arp's 1966 "Atlas of Peculiar Galaxies" contains only its Table 2 published in the Astrophysical Journal Supplement.
- ID:
- ivo://CDS.VizieR/J/ApJS/158/139
- Title:
- Atlas of warm AGN and starbursts
- Short Name:
- J/ApJS/158/139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a set of 180 active galactic nucleus (AGN) candidates based on color selection from the IRAS slow-scan deep observations, with color criteria broadened from the initial Point Source Catalog (Cat. <II/125>) samples so as to include similar objects with redshifts up to z=1 and allowing for two-band detections. Spectroscopic identifications have been obtained for 80 (44%); some additional identifications are secure based on radio detections or optical morphology, although yet unobserved spectroscopically. These spectroscopic identifications include 13 type-1 Seyfert galaxies, 17 type-2 Seyferts, 29 starburst galaxies, 7 LINER systems, and 13 emission-line galaxies so heavily reddened as to remain of ambiguous classification.
- ID:
- ivo://CDS.VizieR/J/other/RAA/11.924
- Title:
- Atmospheric parameters for 771 stars
- Short Name:
- J/other/RAA/11.9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way. Their exploitation requires reliable automated methods and softwares to measure the fundamental parameters of the stars. Adopting the ULySS package, we have tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effective temperature Teff, surface gravity logg, and metallicity [Fe/H]). We show that ULySS is reliable to determine these parameters with medium-resolution spectra (R~2000). Then, we applied the method to measure the parameters of 771 stars selected in the commissioning database of the Guoshoujing Telescope (GSJT). The results were compared with the SDSS/SEGUE Stellar Parameter Pipeline (SSPP), and we derived precisions of 167K, 0.34dex, and 0.16dex for Teff, logg and [Fe/H] respectively. Furthermore, 120 of these stars are selected to construct the primary stellar spectra template library (Version 1.0) of GSJT, and will be deployed as basic ingredients for the GSJT automated parametrization pipeline.
- ID:
- ivo://CDS.VizieR/J/A+A/525/A71
- Title:
- Atmospheric parameters for 1273 stars
- Short Name:
- J/A+A/525/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Empirical libraries of stellar spectra play an important role in different fields. For example, they are used as reference for the automatic determination of atmospheric parameters, or for building synthetic stellar populations to study galaxies. The CFLIB (Coude-feed library, Indo-US) database is at present one of the most complete libraries, in terms of its coverage of the atmospheric parameters space (Teff, logg and [Fe/H]) and wavelength coverage 3460-9464{AA} at a resolution of ~1{AA} FWHM. Although the atmospheric parameters of most of the stars were determined from detailed analyses of high-resolution spectra, for nearly 300 of the 1273 stars of the library at least one of the three parameters is missing. For the others, the measurements, compiled from the literature, are inhomogeneous. In this paper, we re-determine the atmospheric parameters, directly using the CFLIB spectra, and compare them to the previous studies. Methods. We use the ULySS program to derive the atmospheric parameters, using the ELODIE library as a reference. Based on comparisons with several previous studies we conclude that our determinations are unbiased. For the 958 F,G, and K type stars the precision on Teff, logg, and [Fe/H] is respectively 43K, 0.13dex and 0.05dex. For the 53 M stars they are 82K, 0.22dex and 0.28dex. And for the 260 OBA type stars the relative precision on Teff is 5.1%, and on logg, and [Fe/H] the precision is respectively 0.19 dex and 0.16 dex. These parameters will be used to re-calibrate the CFLIB fluxes and to produce synthetic spectra of stellar populations.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A143
- Title:
- Atmospheric parameters of stars for UV models
- Short Name:
- J/A+A/538/A143
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spectral predictions of stellar population models are not as accurate in the ultra-violet (UV) as in the optical wavelength domain. One of the reasons is the lack of high-quality stellar libraries. The New Generation Stellar Library (NGSL), recently released, represents a significant step towards the improvement of this situation. To prepare NGSL for population synthesis, we determined the atmospheric parameters of its stars, we assessed the precision of the wavelength calibration and characterised its intrinsic resolution. We also measured the Galactic extinction for each of the NGSL stars. For our analyses we used ULySS, a full spectrum fitting package, fitting the NGSL spectra against the MILES interpolator. We find that the wavelength calibration is precise up to 0.1pix, after correcting a systematic effect in the optical range. The spectral resolution varies from 3{AA} in the UV to 10{AA} in the near-infrared (NIR), corresponding to a roughly constant reciprocal resolution R~1000 and an instrumental velocity dispersion 130km/s. We derived the atmospheric parameters homogeneously. The precision for the FGK stars is 42K, 0.24 and 0.09dex for Teff, logg and [Fe/H], respectively. The corresponding mean errors are 29K, 0.50 and 0.48dex for the M stars, and for the OBA stars they are 4.5 percent, 0.44 and 0.18dex. The comparison with the literature shows that our results are not biased.
