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1201. ATLASGAL-selected massive clumps. Chemistry of PDR
ID:
ivo://CDS.VizieR/J/A+A/644/A160
Title:
ATLASGAL-selected massive clumps. Chemistry of PDR
Short Name:
J/A+A/644/A160
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study ten molecular transitions obtained from an unbiased 3mm molecular line survey using the IRAM 30m telescope toward 409 compact dust clumps identified by the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) to better understand the photodissociation regions (PDRs) associated with these clumps. The main goal of this study is to investigate whether the abundances of the selected molecules show any variations resulting from the PDR chemistry in different clump environments. We selected HCO, HOC^+^, C_2_H, c-C_3_H_2_, CN, H^13^CN, HC^15^N, and HN^13^C as PDR tracers, and H^13^CO^+^ and C^18^O as dense gas tracers. By using estimated optical depths of C_2_H and H^13^CN and assuming optically thin emission for other molecular transitions, we derived the column densities of those molecules and their abundances. To assess the influence of the presence and strength of ultra- violet radiation, we compare abundances of three groups of the clumps: HII regions, infrared bright non-HII regions, and infrared dark non-HII regions. We detected C^18^O, H^13^CO^+^, C_2_H, c-C_3_H_2_, CN, and HN^13^C toward most of the observed dust clumps (detection rate >94%), and H^13^CN is also detected with a detection rate of 75%. On the other hand, HCO and HC^15^N show detection rates of 32% and 39%, respectively, toward the clumps, which are mostly associated with HII region sources: Detection rates of HCO and HC^15^N toward the HII regions are 66% and 79%. We find that the abundances of HCO, CN, C_2_H, and c-C_3_H_2_ decrease as the H_2_ column density increases, indicating high visual extinction, while those of high-density tracers (i.e., H^13^CO^+^ and HC^15^N) are constant. In addition, N(HCO)/N(H^13^CO^+^) ratios significantly decrease as H_2_ column density increases, and, in particular, 82 clumps have X(HCO)>=10^-10^ and N(HCO)/N(H^13^CO^+^)>~1, which are indications of far-ultraviolet (FUV) chemistry. This suggests the observed HCO abundances are likely associated with FUV radiation illuminating the PDRs. We also find that high N(c-C_3_H_2_)/N(C_2_H) ratios found for HII regions that have high HCO abundances (>~10^-10^) are associated with more evolved clumps with high L_bol_/M_clump_. This trend might be associated with gain-surface processes, which determine the initial abundances of these molecules, and time-dependent effects in the clumps corresponding to the envelopes around dense PDRs and HII regions. In addition, some fraction of the measured abundances of the small hydrocarbons of the HII sources may be the result of the photodissociation of PAH molecules.
1202. ATLAS 1.4GHz Data Release 2
ID:
ivo://CDS.VizieR/J/MNRAS/441/2555
Title:
ATLAS 1.4GHz Data Release 2
Short Name:
J/MNRAS/441/2555
Date:
21 Oct 2021
Publisher:
CDS
Description:
This is the first of two papers describing the second data release (DR2) of the Australia Telescope Large Area Survey at 1.4GHz, which comprises deep wide-field observations in total intensity, linear polarization, and circular polarization over the Chandra Deep Field-South and European Large Area Infrared Space Observatory Survey-South 1 regions. DR2 improves upon the first data release by maintaining consistent data reductions across the two regions, including polarization analysis, and including differential number counts in total intensity and linear polarization. Typical DR2 sensitivities across the mosaicked multipointing images are 30{mu}Jy/beam at approximately 12"x6" resolution over a combined area of 6.4deg^2^. In this paper we present detailed descriptions of our data reduction and analysis procedures, including corrections for instrumental effects such as positional variations in image sensitivity, bandwidth smearing with a non-circular beam, and polarization leakage, and application of the BLOBCAT source extractor. We present the DR2 images and catalogues of components (discrete regions of radio emission) and sources (groups of physically associated radio components). We describe new analytic methods to account for resolution bias and Eddington bias when constructing differential number counts of radio components.
1203. ATLAS 1.4GHz Data Release 3
ID:
ivo://CDS.VizieR/J/MNRAS/453/4020
Title:
ATLAS 1.4GHz Data Release 3
Short Name:
J/MNRAS/453/4020
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the third data release from the Australia Telescope Large Area Survey. These data combine the observations at 1.4GHz before and after upgrades to the Australia Telescope Compact Array reaching a sensitivity of 14{mu}Jy/beam in 3.6 deg^2^ over the Chandra Deep Field South (CDFS) and of 17{mu}Jy/beam in 2.7 deg^2^ over the European Large Area ISO Survey South 1 (ELAIS-S1). We used a variety of array configurations to maximize the uv coverage resulting in a resolution of 16 by 7-arcsec in CDFS and of 12 by 8-arcsec in ELAIS-S1. After correcting for peak bias and bandwidth smearing, we find a total of 3034 radio source components above 5{sigma} in CDFS, of which 514 (17 per cent) are considered to be extended. The number of components detected above 5{sigma} in ELAIS-S1 is 2084, of which 392 (19 per cent) are classified as extended. The catalogues include reliable spectral indices ({Delta}{alpha}<0.2) between 1.40 and 1.71GHz for ~350 of the brightest components.
1204. ATLAS 2.3GHz observations of ELAIS-S1 and CDF-S
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).
1205. ATLAS 5.5GHz survey of Chandra Deep Field South
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.
1206. Atlas of HI absorption toward HII regions in SGPS I
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.
1207. Atlas of HST STIS spectra of Seyfert galaxies
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 .
1208. Atlas of 840-880nm spectral region
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.
1209. Atlas of Optical Spectral Classification OB Stars
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.
1210. Atlas of Peculiar Galaxies
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.

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