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14531. 160 square degree ROSAT survey
ID:
ivo://CDS.VizieR/J/ApJ/594/154
Title:
160 square degree ROSAT survey
Short Name:
J/ApJ/594/154
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the revised catalog of galaxy clusters detected as extended X-ray sources in the 160 Square Degree ROSAT Survey, including spectroscopic redshifts and X-ray luminosities for 200 of the 201 members. The median redshift is z_median_=0.25, and the median X-ray luminosity is L_X,median_=4.2x10^43^h_50_^2^erg/s (0.5-2.0keV). This is the largest high-redshift sample of X-ray-selected clusters published to date. There are 73 objects at z>0.3 and 22 objects at z>0.5 drawn from a statistically complete flux-limited survey with a median object flux of 1.4x10^-13^erg/cm^2^/s. We describe the optical follow-up of these clusters with an emphasis on our spectroscopy, which has yielded 155 cluster redshifts, 110 of which are presented here for the first time. These measurements, combined with 45 from the literature and other sources, provide near-complete spectroscopic coverage for our survey. We discuss the final optical identifications for the extended X-ray sources in the survey region and compare our results to similar X-ray cluster searches.
14532. Square Kilometre Array Science Data Challenge 1
ID:
ivo://CDS.VizieR/J/MNRAS/500/3821
Title:
Square Kilometre Array Science Data Challenge 1
Short Name:
J/MNRAS/500/3821
Date:
21 Oct 2021
Publisher:
CDS
Description:
As the largest radio telescope in the world, the Square Kilometre Array (SKA) will lead the next generation of radio astronomy. The feats of engineering required to construct the telescope array will be matched only by the techniques developed to exploit the rich scientific value of the data. To drive forward the development of efficient and accurate analysis methods, we are designing a series of data challenges that will provide the scientific community with high-quality datasets for testing and evaluating new techniques. In this paper we present a description and results from the first such Science Data Challenge (SDC1). Based on SKA MID continuum simulated observations and covering three frequencies (560MHz, 1400MHz and 9200MHz) at three depths (8h, 100h and 1000h), SDC1 asked participants to apply source detection, characterization and classification methods to simulated data. The challenge opened in November 2018, with nine teams submitting results by the deadline of April 2019. In this work we analyse the results for 8 of those teams, showcasing the variety of approaches that can be successfully used to find, characterise and classify sources in a deep, crowded field. The results also demonstrate the importance of building domain knowledge and expertise on this kind of analysis to obtain the best performance. As high-resolution observations begin revealing the true complexity of the sky, one of the outstanding challenges emerging from this analysis is the ability to deal with highly resolved and complex sources as effectively as the unresolved source population.
14533. Srg tidal tails red giants properties
ID:
ivo://CDS.VizieR/J/A+A/597/A54
Title:
Srg tidal tails red giants properties
Short Name:
J/A+A/597/A54
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim to measure the metallicity distribution and velocity distribution of red giant branch (RGB) stars along the Sagittarius dwarf galaxy (Sgr) streams. Thanks to the large number of stars of the Sloan Digital Sky Survey (SDSS) sample, we can study the properties of streams as a function of the {LAMBDA}s from the Sgr core. Using the ~22000 RGB stars from the ninth data release of SDSS, we selected 1100 RGB stars belonging to the streams of the Sgr. As compared with red horizontal branch stars (Shi et al., 2012, Cat. J/ApJ/751/130) the RGB stars constitute a large sample size and extend to a metal-poor component of [Fe/H]~-3.0dex. In particular, this RGB sample has a significant number of stars in the second wrap of the leading stream of the Sgr (leading arm 2), and thus provides a good opportunity to understand the properties of the leading stream.
14534. SSA22 Field Chandra X-Ray Point Source Catalog
ID:
ivo://nasa.heasarc/ssa22cxo
Title:
SSA22 Field Chandra X-Ray Point Source Catalog
Short Name:
SSA22CXO
Date:
09 May 2025
Publisher:
NASA/GSFC HEASARC
Description:
This table contains the main X-ray point-source catalog for a deep ~400-ks Chandra ACIS-I (Advanced CCD Imaging Spectrometer) exposure of the SSA22 field. The observations were centred on a z = 3.09 protocluster, which is populated by Lyman break galaxies (LBGs), Lyman-alpha emitters (LAEs) and extended Lyman-alpha-emitting blobs (LABs). The survey reached ultimate (3 count) sensitivity limits of ~5.7 x 10<sup>-17</sup> and ~3.0 x 10<sup>-16</sup> erg cm<sup>-2</sup> s<sup>-1</sup> for the 0.5-2 and 2-8 keV bands, respectively (corresponding to L(2-10 keV) ~ 5.7 x 10<sup>42</sup> erg s<sup>-1</sup> and L(10-30 keV) ~ 2.0 x 10<sup>43</sup> erg s<sup>-1</sup> at z = 3.09, respectively, for an assumed photon index of Gamma = 1.4). These limits make SSA22 the fourth deepest extragalactic Chandra survey yet conducted, and the only one focused on a known high-redshift structure. In total, the authors detect 297 X-ray point sources and identify one obvious bright extended X-ray source (not included in the current table) over a ~330 arcmin<sup>2</sup> region. In addition to the X-ray data, the authors provide all available optical spectroscopic redshifts and near-infrared and mid-infrared photometry available for their sources. The basic X-ray and infrared properties of their Chandra sources indicate a variety of source types, although absorbed active galactic nuclei (AGN) appear to dominate. In total, they have identified 12 X-ray sources (either via optical spectroscopic redshifts or LAE selection) at z = 3.06 - 3.12 that are likely to be associated with the SSA22 protocluster. These sources have X-ray and multiwavelength properties that suggest they are powered by AGN with 0.5 - 8 keV luminosities in the range of ~ 10<sup>43</sup> - 10<sup>45</sup> erg s<sup>-1</sup>. The authors have analysed the AGN fraction of sources in the protocluster as a function of local LAE source density and find suggestive evidence for a correlation between AGN fraction and local LAE source density (at the ~96 per cent confidence level), implying that supermassive black hole growth at z ~3 is strongest in the highest density regions. This table was created by the HEASARC in February 2010 based on the electronic version of Table 2 from the reference paper which was obtained from the Monthly Notices web site. This is a service provided by NASA HEASARC .
14535. SSA 22 field NIR imaging
ID:
ivo://CDS.VizieR/J/PASJ/53/653
Title:
SSA 22 field NIR imaging
Short Name:
J/PASJ/53/653
Date:
21 Oct 2021
Publisher:
CDS
Description:
Deep narrow- and broad-band near-infrared imaging observations of the central 2'x2' region of the SSA 22 field were made with the near-infrared camera (CISCO) attached to the Subaru Telescope. Using a narrow-band filter centered at 2.033{mu}m, [O III] {lambda}5007 emitters at z~3.06+/-0.02 were searched to examine star-forming activities in an over-density region where a clustering of Lyman Break Galaxies (LBGs) and Lyman {alpha} emitter candidates around z=3.09 was reported, though the targeted redshift is slightly different from that of the peak of the over-density region. Although one emitter candidate at z=3.06 was detected, it is likely to be located at a redshift of between 1 and 2 judged based on multi-band photometry. Another emission-line object was detected in another narrow-band filter (``off band'' filter) centered at 2.120{mu}m, which is identified with a galaxy at z=0.132 (the emission line is Paschen {alpha}). The K'-band imaging data revealed the presence of 12 Extremely Red Objects (EROs) with I_814_-K'>=4. The distribution of the EROs does not seem to coincide with that of Lyman Break Galaxies or Lyman {alpha} emitters at z~3. The magnitudes and colors of the EROs are not consistent with those of passively evolving massive elliptical galaxies at z~3. Candidates for counterparts of the submm sources detected with SCUBA are found; no EROs around the submm sources are found in our magnitude limit.
14536. (S+S) binary galaxies BVRI photometry
ID:
ivo://CDS.VizieR/J/A+A/379/54
Title:
(S+S) binary galaxies BVRI photometry
Short Name:
J/A+A/379/54
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present multicolour broad band (BVRI) photometry for a sample of 33 spiral-spiral (S+S) binary galaxies drawn from the Karachentsev Catalogue of Isolated Pairs of Galaxies (KPG, Cat. <VII/77>). The data is part of a joint observational programme devoted to systematic photometric study of one of the most complete and homogeneous pair samples available in the literature. We present azimuthally averaged colour and surface brightness profiles, colour index (B-I) maps, B band and sharp/filtered B band images as well as integrated magnitudes, magnitudes at different circular apertures and integrated colours for each pair. Internal and external data comparisons show consistency within the estimated errors. Two thirds of the sample have total aperture parameters homogeneously derived for the first time. After reevaluating morphology for all the pairs, we find a change in Hubble type for 24 galaxies compared to the original POSS classifications. More than half of our pairs show morphological concordance which could explain, in part, the strong correlation in the (B-V) colour indices (Holmberg Effect) between pair components. We find a tendency for barred galaxies to show grand design morphologies and flat colour profiles. The measurements will be used in a series of forthcoming papers where we try to identify and isolate the main structural and photometric properties of disk galaxies at different stages of interaction.
14537. SS(77) Catalogue: new H-alpha em* in Milky Way
ID:
ivo://CDS.VizieR/III/180
Title:
SS(77) Catalogue: new H-alpha em* in Milky Way
Short Name:
III/180
Date:
21 Oct 2021
Publisher:
CDS
Description:
Data on 455 H-{alpha} emission stars found in all parts of the Milky Way, virtually all previously unpublished, are tabulated, with newly measured coordinates usually accurate to better than 2". A half-dozen stars appear to have been published previously with erroneous coordinates, or to have been published but omitted from the general catalog by Wackerling (1970MmRAS..73..153W). Included among the new stars are known OB stars of the Luminous Stars in the Northern Milky Way survey, from the Hamburg zones, which were originally searched for H{alpha} emission at slightly lower spectral resolution than we have used. The stars are in general of early spectral type, and are mostly fainter than the limits of the DM catalogs. The objective-prism plates covered the entire Milky Way within about 10deg of the galactic equator, at a spectral dispersion of about 1000{AA}/mm at H-alpha.
14538. SSDF survey: IRAC catalogs
ID:
ivo://CDS.VizieR/J/ApJS/209/22
Title:
SSDF survey: IRAC catalogs
Short Name:
J/ApJS/209/22
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Spitzer South Pole Telescope Deep Field (SSDF) is a wide-area survey using Spitzer's Infrared Array Camera (IRAC) to cover 94deg^2^ of extragalactic sky, making it the largest IRAC survey completed to date outside the Milky Way midplane. The SSDF is centered at ({alpha},{delta})=(23:30, -55:00), in a region that combines observations spanning a broad wavelength range from numerous facilities. These include millimeter imaging from the South Pole Telescope (SPT), far-infrared observations from Herschel/SPIRE, X-ray observations from the XMM XXL survey, near-infrared observations from the VISTA Hemisphere Survey, and radio-wavelength imaging from the Australia Telescope Compact Array, in a panchromatic project designed to address major outstanding questions surrounding galaxy clusters and the baryon budget. Here we describe the Spitzer/IRAC observations of the SSDF, including the survey design, observations, processing, source extraction, and publicly available data products. In particular, we present two band-merged catalogs, one for each of the two warm IRAC selection bands. They contain roughly 5.5 and 3.7 million distinct sources, the vast majority of which are galaxies, down to the SSDF 5{sigma} sensitivity limits of 19.0 and 18.2 Vega mag (7.0 and 9.4uJy) at 3.6 and 4.5um, respectively.
14539. SSRS groups of galaxies redshift neighbourhood
ID:
ivo://CDS.VizieR/J/A+A/312/745
Title:
SSRS groups of galaxies redshift neighbourhood
Short Name:
J/A+A/312/745
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Southern Sky Redshift Survey (SSRS) includes 13 groups of 5 or more members with velocities >=2000km/s. By measuring redshifts and accumulating data from the literature, we increase the total number of known group members from 89 to 218. We also measured new redshifts for 59 foreground/background galaxies superimposed on the group neighborhoods. The velocity dispersions of the groups are remarkably stable.
14540. S254-S258 Star-Forming Region Chandra X-Ray Point Source Catalog
ID:
ivo://nasa.heasarc/s254258cxo
Title:
S254-S258 Star-Forming Region Chandra X-Ray Point Source Catalog
Short Name:
S254258CXO
Date:
09 May 2025
Publisher:
NASA/GSFC HEASARC
Description:
The aim of this study was to find an explanation for the remarkable morphology of the central part of the S254-S258 star forming complex. The authors performed a deep Chandra X-ray observation of the S254-S258 region in order to efficiently discriminate young stars (with and without circumstellar matter) from the numerous older field stars in the area. They detected 364 X-ray point sources in a 17&#39; x 17&#39; (~ 8 x 8 pc) field. This X-ray catalog provides, for the first time, a complete sample of all young stars in the region down to about 0.5 M_{sun}_. A clustering analysis identifies three significant clusters: the central embedded cluster S255-IR and two smaller clusterings in S256 and S258. Sixty-four X-ray sources can be classified as members in one of these clusters. After accounting for X-ray background contaminants, this implies that about 250 X-ray sources constitute a widely scattered population of young stars, distributed over the full field-of-view of the X-ray image. This distributed young stellar population is considerably larger than the previously known number of non-clustered young stars selected by infrared excesses. Comparison of the X-ray luminosity function with that of the Orion Nebula Cluster suggests a total population of ~ 2000 young stars in the observed part of the S254-S258 region. The S254-S258 complex was observed (PI: Preibisch) in November 2009 with the Imaging Array of the Chandra Advanced CCD Imaging Spectrometer (ACIS-I). ACIS-I provides a field of view of 17&#39; x 17&#39; on the sky. At the 1.6 kpc distance of S254-S258 this corresponds to 7.9 x 7.9 pc. The aimpoint of the observation was RA(J2000) = 06h12m54.0s, Dec(J2000) = +17d 59&#39; 24&quot;. The observation was performed in the standard &#39;Timed Event, Faint&#39; mode (with 3 x 3 pixel event islands). The total net exposure time of 74725 s (20.76 h) was split into two parts, separated by about 4 days. The details of these two observation parts are given in Table 1 of the reference paper. The authors first employed the wavdetect algorithm (Freeman et al. 2002, ApJS, 138, 185, a CIAO mexican-hat wavelet source detection tool) for locating X-ray sources in the merged image, and used a rather low detection threshold of 10&lt;sup&gt;-5&lt;/sup&gt;. This step was performed in three different energy bands, the total band (0.5 - 8.0 keV), the soft band (0.5 - 2.0 keV), and the hard band (2.0 - 8.0) keV, and with wavelet scales between 1 and 16 pixels. They also performed a visual inspection of the images and added some 30 additional candidates to the merged catalog from the wavelet analysis, resulting in a final catalog of 511 potential X-ray sources. To clean this catalog from spurious sources, they then performed a detailed analysis of each individual candidate source with the ACIS Extract (AE hereafter) software package (Broos et al. 2010, ApJ, 714, 1582). The Poisson probability (P&lt;sub&gt;B&lt;/sub&gt;) associated with the &quot;null hypothesis&quot;, i.e. that no source exists and the extracted events are solely due to Poisson fluctuations in the local background, was computed for each source using AE. All candidate sources with P&lt;sub&gt;B&lt;/sub&gt; &gt; 0.01 were rejected as background fluctuations. After 8 iterations of this pruning procedure the final catalog consisted of 364 sources. It contains 344 primary sources with P&lt;sub&gt;B&lt;/sub&gt; &lt; 0.003, and 20 tentative sources with 0.003 &lt; P&lt;sub&gt;B&lt;/sub&gt; &lt; 0.01. To obtain an estimate of the intrinsic, i.e. extinction-corrected, X-ray luminosity for sources that are too weak for a detailed spectral analysis, the authors used the XPHOT software, developed by Getman et al. (2010, ApJ, 708, 1760). XPHOT is based on a non-parametric method for the calculation of fluxes and absorbing X-ray column densities of weak X-ray sources. X-ray extinction and intrinsic flux are estimated from the comparison of the apparent median energy of the source photons and apparent source flux with those of high signal-to-noise spectra that were simulated using spectral models characteristic of much brighter sources of similar class previously studied in detail. This method requires at least 4 net counts per source (in order to determine a meaningful value for the median energy) and can thus be applied to 255 of the 364 sources in this table. To calculate luminosities, a distance of 1.6 kpc was assumed. The resulting intrinsic X-ray lumonosities range from 10&lt;sup&gt;29.4&lt;/sup&gt; to 10&lt;sup&gt;32.3&lt;/sup&gt; erg s&lt;sup&gt;-1&lt;/sup&gt;. This table was created by the HEASARC in October 2011 based on &lt;a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/533/A121"&gt;CDS Catalog J/A+A/533/A121&lt;/a&gt; files table2.dat, table3.dat and table5.dat. This is a service provided by NASA HEASARC .

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