- ID:
- ivo://nasa.heasarc/sdssunuqsr
- Title:
- Sloan Digital Sky Survey Unusual Quasars Catalog
- Short Name:
- SDSSUNUQSR
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Large spectroscopic surveys have discovered very peculiar and hitherto unknown types of active galactic nuclei (AGN). Such rare objects may hold clues to the accretion history of the supermassive black holes at the centres of galaxies. The authors aim to create a sizeable sample of unusual quasars from the unprecedented spectroscopic database of the Sloan Digital Sky Survey (SDSS). This table contains a catalog of 1005 quasars with unusual spectra in the redshift interval from 0.6 to 4.3. [HEASARC Note: the redshifts in this table actually range from 0.497 to 4.771]. The quasars were selected from the Sloan Digital Sky Survey Data Release 7 (Abazajian et al., 2009, ApJS, 182, 543) by means of Kohonen self-organising maps. The spectra are dominated by either broad absorption lines (42%), unusual red continua (27%), weak emission lines (18%), or conspicuously strong optical and/or UV iron emission (11%). This large sample provides a useful resource for both studying properties and relations of/between different types of unusual quasars and selecting particularly interesting objects, even though the compilation is not aimed at completeness in a quantifiable sense. The spectra are grouped into seven types. The catalogue contains the redshift, the absolute magnitude, the spectral type, the radio loudness parameter, a peculiarity index, and some comments on peculiar spectral features. This table was created by the HEASARC in May 2012 based on CDS table J/A+A/541/A77 file table3.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/agnsdssxmm
- Title:
- Sloan Digital Sky Survey/XMM-Newton AGN Spectral Properties Catalog
- Short Name:
- AGNSDSSXMM
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Bright XMM-Newton data are combined with the Chandra Deep Field South observations to explore the behavior of the intrinsic AGN absorption, as a function of redshift and luminosity. The sample consists of 359 sources selected in the hard 2 - 8 keV band, spanning the flux range from 6 x 10<sup>-16</sup> - 3 x 10<sup>-13</sup> erg/cm<sup>2</sup>/s with a high rate of spectroscopic or photometric redshift completeness (100 and 85 percent for the Chandra and XMM-Newton data, respectively). The authors derive the column density values using X-ray spectral fits. They find that the fraction of obscured AGN falls with increasing luminosity in agreement with previous findings. The fraction of obscured AGN shows an apparent increase at high redshifts (z > 2). Simulations show that this effect can most probably be attributed to the fact that at high redshifts the column densities are overestimated. This table contains the subset of 153 brighter hard X-ray sources in the XMM-Newton/Sloan Digital Sky Survey (SDSS) sample which have 2-8 keV fluxes > 3 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, excluding a number of sources with extended optical morphology and blue colors, as well as 4 sources with X-ray to optical fluxes < 0.1 which are fit better with stellar rather than QSO templates. Much more information on the SDSS is available at the project's web site at <a href="http://www.sdss.org/">http://www.sdss.org/</a>. This table was created by the HEASARC in July 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/459/693">CDS Catalog J/A+A/459/693</a> file table2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/agnsdssxm2
- Title:
- Sloan Digital Sky Survey/XMM-Newton Type1 AGN X-Ray and Radio Properties Catalog
- Short Name:
- AGNSDSSXM2
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- X-ray emission from active galactic nuclei (AGN) is dominated by the accretion disk around a supermassive black hole. The radio luminosity, however, has not such a clear origin except in the most powerful sources where jets are evident. The origin (and even the very existence) of the local bi-modal distribution in radio-loudness is also a debated issue. By analyzing X-ray, optical and radio properties of a large sample of type 1 AGN and quasars (QSOs) up to z > 2, where the bulk of this population resides, the authors aim to explore the interplay between radio and X-ray emission in AGN, in order to further our knowledge on the origin of radio emission, and its relation to accretion. They analyze a large (~800 sources) sample of type 1 AGN and QSOs selected from the 2XMMi XMM-Newton X-ray source catalog, cross-correlated with the SDSS DR7 spectroscopic catalog, covering a redshift range from z ~ 0.3 to z ~ 2.3. Supermassive black hole masses are estimated from the Mg II emission line, bolometric luminosities from the X-ray data, and radio emission or upper limits from the FIRST catalog. Most of the sources accrete close to the Eddington limit and the distribution in radio-loudness does not appear to have a bi-modal behavior. This study confirms that radio-loud AGN are also X-ray loud, with an X-ray-to-optical ratio up to twice that of radio-quiet objects, even excluding the most extreme strongly jetted sources. By analyzing complementary radio-selected control samples, the authors find evidence that these conclusions are not an effect of the X-ray selection, but are likely a property of the dominant QSO population. The authors of this catalog conclude that their findings are best interpreted in a context where radio emission in AGN, with the exception of a minority of beamed sources, arises from very close to the accretion disk and is therefore heavily linked to X-ray emission. They also speculate that the radio-loud/radio-quiet dichotomy might either be an evolutionary effect that developed well after the QSO peak epoch, or an effect of incompleteness in small samples. Basic information and derived properties are presented for the sample of X-ray selected type 1 AGN (as well as for the 11 X-ray undetected type 1 AGN in the "control sample"): coordinates, redshift, X-ray and radio fluxes, optical magnitudes, from the SDSS, 2XMMi, and FIRST catalogs; continuum luminosities at 3000 Angstroms and in the X-ray band, black hole masses, bolometric luminosities, Eddington ratios; for the sources falling in the FIRST field, optical fluxes at 2500 and 4400 Angstroms, X-ray-to-optical index, radio classification, and the ratios between the radio and the UV, optical, and X-ray fluxes. This table was created by the HEASARC in October 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/545/A66">CDS Catalog J/A+A/545/A66</a> files table3.dat, table4.dat and table5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smc1400mhz
- Title:
- Small Magellanic Cloud ATCA and Parkes 1400-MHz Source Catalog
- Short Name:
- SMC1400MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a new catalog of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). This catalog contains 1560 radio-continuum sources detected at 1400 MHz (lambda = 20 cm) from a set of new high-resolution radio-continuum mosaic images of the SMC created by combining observations from ATCA and Parkes (Wong et al. 2011, SerAJ, 182, 43). The 20 cm mosaic image (Fig. 2 in above reference)was created by combining data from ATCA project C1288 (Mao et al. 2008, ApJ, 688, 1029) with data obtained for a Parkes radio-continuum study of the SMC (Filipovic et al. 1997, A&AS, 121, 321). This image had a beam size of 17.8 x 12.2 arcseconds and an rms noise of 0.7 mJy/beam. The MIRIAD task 'imsad' was used to detect sources in the 20-cm image, requiring a fitted Gaussian flux density > 5 sigma (3.5 mJy). All sources were then visually examined to confirm that they were genuine point sources, excluding extended emission, bright side lobes, etc. This table was created by the HEASARC in September 2014 based on CDS Catalog J_other/Ser/183.103/ file tablea2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smc8640mhz
- Title:
- Small Magellanic Cloud ATCA 8640-MHz Source Catalog
- Short Name:
- SMC8640MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a new catalog of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). This catalog contains sources found at 8640 MHz (lambda = 3 cm) by combining data from various Australia Telescope Compact Array (ATCA) projects that covered the SMC. Some 457 sources have been detected at 3 cm in the new high-sensitivity and resolution radio-continuum image of the SMC from Crawford et al. (2011, SerAJ, 183, 95). The 3 cm map has a resolution of 20 arcseconds, and a sensitivity of 0.8 mJy/beam. The field size of the image used in this study covered from 00<sup>h</sup> 26<sup>m</sup> to 01<sup>h</sup> 27<sup>m</sup> in RA (J2000.0) and from -70<sup>o</sup> 35' to -75<sup>o</sup> 21' in Dec (J2000.0). The MIRIAD task 'imsad' was used to detect sources in the 3 cm image, requiring a fitted Gaussian flux density > 5 sigma (3.5 mJy). All sources were then visually examined to confirm that they are genuine point sources, excluding extended emission, bright side lobes, etc. This table was created by the HEASARC in September 2014 based on CDS Catalog J_other/Ser/184.93/ file tablea1.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smc4800mhz
- Title:
- Small Magellanic Cloud ATCA 4800-MHz Source Catalog
- Short Name:
- SMC4800MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a new catalog of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). This catalog contains sources found at 4800 MHz (lambda = 6 cm) by combining data from various Australia Telescope Compact Array (ATCA) projects that covered the SMC. Some 601 sources have been detected at 6 cm in the new high-sensitivity and resolution radio-continuum image of the SMC from Crawford et al. (2011, SerAJ, 183, 95). The 6 cm map has a resolution of 30 arcseconds, and a sensitivity of 0.7 mJy/beam. The field size of the image used in this study covered from 00<sup>h</sup> 26<sup>m</sup> to 01<sup>h</sup> 28<sup>m</sup> in RA (J2000.0) and from -70<sup>o</sup> 29' to -75<sup>o</sup> 29' in Dec (J2000.0). The MIRIAD task 'imsad' was used to detect sources in the 6 cm image, requiring a fitted Gaussian flux density > 5 sigma (3.5 mJy). All sources were then visually examined to confirm that they are genuine point sources, excluding extended emission, bright side lobes, etc. This table was created by the HEASARC in September 2014 based on CDS Catalog J_other/Ser/184.93/ file tablea2.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smcradio
- Title:
- Small Magellanic Cloud ATCA Radio Continuum Sources
- Short Name:
- SMCRadio
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the classification of 717 radio-continuum sources from the Australia Telescope Compact Array (ATCA) Catalog of the Small Magellanic Cloud (SMC). All 717 sources have been categorised into one of three groups: supernova remnants (SNRs), HII regions and background sources. In total, 71 sources are named as HII regions (or candidates) and 21 sources are named as SNRs (or candidates). Six sources are named as either HII regions or background sources and two are candidate radio planetary nebulae. One source is coincident with an X-ray binary. 616 objects are classified as background sources and their statistics are presented in the published paper II from which this table is taken. This table was created by the HEASARC in March 2005 based on CDS table J/MNRAS/355/44/table2.dat . This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smcdfscxo
- Title:
- Small Magellanic Cloud Deep Fields X-Ray Point Source Catalog
- Short Name:
- SMCDFSCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results of a pair of 100 ks Chandra observations of the Small Magellanic Cloud (SMC) to survey high-mass X-ray binaries (HMXBs), stars, and low-mass X-ray binaries (LMXBs)/cataclysmic variables down to L<sub>X</sub> = 4.3 x 10<sup>32</sup> erg s<sup>-1</sup>. The two SMC Deep Fields (DFs) are located in the most active star-forming region of the SMC bar, with Deep Field-1 positioned at the most pulsar-rich location identified from previous surveys. Two new pulsars were discovered in outburst, CXOU J004929.7-731058 (P = 892 s) and CXOU J005252.2-721715 (P = 326 s), and three new HMXB candidates were identified. Of the 15 Be-pulsars now known in the field, 13 were detected, with pulsations seen in 9 of them. Ephemerides demonstrate that 6 of the 10 pulsars known to exhibit regular outbursts were seen outside their periastron phase, and quiescent X-ray emission at L<sub>X</sub> = 10<sup>(33-34)</sup> erg s<sup>-1</sup> is shown to be common. Comparison with ROSAT, ASCA, and XMM-Newton catalogs resulted in positive identification of several previously ambiguous sources. Bright optical counterparts exist for 40 of the X-ray sources, of which 33 are consistent with early-type stars (M<sub>V</sub> < -2, B-V < 0.2), and are the subject of a companion paper to the reference paper. The results point to an underlying HMXB population density up to double that of active systems. The full catalog of 394 point sources is presented in this table; detailed analyses of the source timing and spectral properties are available in the reference paper. The aim-points for these Chandra observations were as follows: DF1 had J2000.0 coordinates of 00 53 34.50 -72 26 43.2 and DF2 had J2000.0 coordinates of 00 50 41.40 -73 16 10.3. This table was created by the HEASARC in August 2010 based on the electronic version of Table 2 from the reference paper which was obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smc843mhz
- Title:
- Small Magellanic Cloud MOST 843-MHz Source Catalog
- Short Name:
- SMC843MHZ
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a new catalog of radio-continuum sources in the field of the Small Magellanic Cloud (SMC). This catalog contains 1689 radio-continuum sources detected at 843 MHz (lambda = 36 cm) from a radio survey of 36 square degrees containing the SMC (Turtle et al. 1998, PASA, 15, 280) conducted using the Molonglo Observatory Synthesis Telescope (MOST). These observations had a beam size of ~ 45 arcseconds and an rms noise of 0.7 mJy/beam. The MIRIAD task 'imsad' was used to detect sources in the 36-cm images, requiring a fitted Gaussian flux density > 5 sigma (3.5 mJy). All sources were then visually examined to confirm that they were genuine point sources, excluding extended emission, bright side lobes, etc. This table was created by the HEASARC in September 2014 based on CDS Catalog J_other/Ser/183.103/ file tablea3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/smcwingcxo
- Title:
- Small Magellanic Cloud Wing Survey Chandra X-Ray Point Source Catalog
- Short Name:
- SMCWINGCXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have detected 523 X-ray sources in a survey of the Small Magellanic Cloud (SMC) Wing with the Chandra X-ray Observatory. By cross-correlating the X-ray data with optical and near-infrared catalogs, they have found 300 matches. Using a technique that combines X-ray colors and X-ray to optical flux ratios, they have been able to assign preliminary classifications to 265 of the objects. The identifications include 4 pulsars, 1 high-mass X-ray binary (HMXB) candidate, 34 stars and 185 active galactic nuclei (AGN). In addition, the authors have classified 32 sources as hard AGN which are likely absorbed by local gas and dust, and 9 soft AGN whose nature is still unclear. Considering the abundance of HMXBs discovered so far in the Bar of the SMC the number that have been detected in the Wing is low. Observations in the Wing of the SMC were made from 2005 July to 2006 March with Chandra. The survey consisted of 20 fields, with exposure times ranging from 8.6 - 10.3 ks. X-ray parameters for 523 sources detected in the Wing of the SMC with Chandra are presented. For each source equatorial coordinates, positional error, net counts (total counts minus background counts) in the 0.5 - 8.0 keV band, signal-to-noise of the detection and source flux in the 0.5 - 8.0 keV band are given. The median, compressed median and normalized quartile ratio of the photon energy distribution, determined using quantile analysis, are given for sources with three or more counts. For the sources that have optical counterparts the V- and R-band magnitudes, B-V color, X-ray to optical flux ratios based on the V- and R-band magnitudes, and a preliminary classification for the sources are given. This table was created by the HEASARC in June 2008 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/383/330">CDS Catalog J/MNRAS/383/330</a> file table2.dat. This is a service provided by NASA HEASARC .
