- ID:
- ivo://CDS.VizieR/J/A+A/544/A38
- Title:
- ATLAS 2.3GHz observations of ELAIS-S1 and CDF-S
- Short Name:
- J/A+A/544/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Australia Telescope Large Area Survey (ATLAS) aims to image a 7deg^2^ region centred on the European Large Area ISO Survey - South 1 (ELAIS-S1) field and the Chandra Deep Field South (CDF-S) at 1.4GHz with high sensitivity (up to {sigma}~10uJy) to study the evolution of star-forming galaxies (SFGs) and Active Galactic Nuclei (AGN) over a wide range of cosmic time. We present here ancillary radio observations at a frequency of 2.3GHz obtained with the Australia Telescope Compact Array (ATCA). The main goal of this is to study the radio spectra of an unprecedented large sample of sources (~2000 observed, ~600 detected in both frequencies).
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- ID:
- ivo://CDS.VizieR/J/MNRAS/426/2342
- Title:
- ATLAS 5.5GHz survey of Chandra Deep Field South
- Short Name:
- J/MNRAS/426/2342
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Star-forming galaxies are thought to dominate the sub-mJy radio population, but recent work has shown that low-luminosity active galactic nuclei (AGNs) can still make a significant contribution to the faint radio source population. Spectral indices are an important tool for understanding the emission mechanism of the faint radio sources. We have observed the extended Chandra Deep Field South at 5.5GHz using a mosaic of 42 pointings with the Australia Telescope Compact Array. Our image reaches an almost uniform sensitivity of ~12Jy rms over 0.25deg^2^ with a restoring beam of 4.9"x2.0", making ATLAS 5.5GHz survey one of the deepest 6cm surveys to date. We present the 5.5GHz catalogue and source counts from this field. We take advantage of the large amount of ancillary data in this field to study the 1.4 to 5.5GHz spectral indices of the sub-mJy population.
- 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/J/ApJS/211/29
- Title:
- Atlas of HI absorption toward HII regions in SGPS I
- Short Name:
- J/ApJS/211/29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a complete catalog of H I emission and absorption spectrum pairs, toward H II regions, detectable within the boundaries of the Southern Galactic Plane Survey (SGPS I), a total of 252 regions. The catalog is presented in graphical, numerical, and summary formats. We demonstrate an application of this new data set through an investigation of the locus of the Near 3kpc Arm.
- ID:
- ivo://CDS.VizieR/J/ApJS/107/281
- Title:
- Atlas of hot, luminous stars at 2 microns
- Short Name:
- J/ApJS/107/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 2um (K band) spectra of 180 well-studied, optically visible, luminous stars. Most of the stars are of OB spectral type, but we have also included a number of Oe and Be stars, OBN and OBC stars, cool hypergiant stars, and high-mass X-ray binary stars. Our aim in studying normal OB stars is to develop an empirical relationship between 2um spectral features of these massive stars and their stellar temperature and luminosity. We find the system of lines between 2.0 and 2.2um is particulary good for differentiating the early- and mid-O type stars. In the late-O and early-B stars, differentiation becomes more difficult, as the features show only moderate changes. We have developed a spectral classification system for the K band to be used to estimate effective temperatures of O and early-B stars. We demonstrate that K-band spectroscopy is superior in estimating the temperature of hot, luminous stars than the traditional methods of using infrared or even optical photometric colors alone. The only requirements are that adequate resolution (R>1000) and signal-to-noise (S/N~70) be achieved. With our classification system, stars behind large amounts of visible extinction, such as young, heavily reddened H II regions throughout our Galaxy, may be identified and studied for the first time through 2um spectroscopy. Emission lines are commonly seen in the K-band spectra of supergiant stars, however, the OBN supergiants, which have a higher ratio of some processed materials at their surface, may be more likely to show line emission, especially the He I singlet transition at 2.058um. This has led us to propose an evolutionary scenario for some of the Galactic center He I emission-line stars, which evokes rotational mixing (Maeder 1987A&A...178..159M; Langer 1992A&A...265L..17L) to explain both the strong line emission and high luminosity of these mysterious sources. We have compared our spectroscopic database with the most recent stellar atmosphere models. We are encouraged by the good match between the model line profiles at 2um of Schaerer et al. (1996A&A...312..475S) and those observed in OB stars. Finally, we include a thorough discussion of the observational and reduction methods employed to obtain the spectra shown in this atlas for the benefit of those wishing to obtain similar, classification-quality, near-infrared spectra.
- ID:
- ivo://CDS.VizieR/J/ApJS/166/498
- Title:
- Atlas of HST STIS spectra of Seyfert galaxies
- Short Name:
- J/ApJS/166/498
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a compilation of spectra of 101 Seyfert galaxies obtained with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS), covering the UV and/or optical spectral range. Information on all the available spectra have been collected in a Mastertable, which is a very useful tool for anyone interested in a quick glance at the existent STIS spectra for Seyfert galaxies in the HST archive, and it can be recovered electronically. Nuclear spectra of the galaxies have been extracted in windows of 0.2" for an optimized sampling (as this is the slit width in most cases) and combined in order to improve the signal-to-noise ratio and provide the widest possible wavelength coverage. These combined spectra are also available electronically, at http://www.if.ufrgs.br/~pat/atlas.htm .
- ID:
- ivo://CDS.VizieR/III/217
- Title:
- Atlas of 840-880nm spectral region
- Short Name:
- III/217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This Atlas illustrates the behavior of stars of all spectral types in the near infrared 8400-8800 Angstrom spectral region with a resolution of about one Angstrom. The spectra have been obtained at the Observatoire de Haute-Provence at a dispersion of 33{AA}/mm. A total of 130 spectra (76 of early-type stars published in Paper I, and 54 of late-type stars published in Paper II) are available. They cover the spectral range O to M and different luminosity classes. The Atlas includes also spectra of stars with spectral peculiarities: 19 from Paper I and 11 from Paper II.
- ID:
- ivo://CDS.VizieR/III/183
- Title:
- Atlas of 837.5-877nm spectral region I.
- Short Name:
- III/183
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/III/195
- Title:
- Atlas of Optical Spectral Classification OB Stars
- Short Name:
- III/195
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Atlas provides digital spectra to assist the classification of OB spectra for 78 standard objects in the wavelength range 395.0-475.0 nm. Spectral types range from O3 - B3 (-B8 at Ia). The Atlas provides contemporary digital data comparable to the earlier printed Atlasses by Morgan et al. (1943), Abt et al. (1968), Yamashita et al. (1977) and Morgan et al. (1978). The digital data were obtained with the Shectman/Heathcote two- dimensional, photon-counting detector on the Casegrain spectrograph at the CTIO 1-meter telescope during October 1988 and March 1989. The 3-pixel resolution is 1.5 Angstroem, and the full wavelength coverage is 3800-5000 A. The data were extracted and rectified by using a uniform template followed by a low-order spine fit.
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