- ID:
- ivo://CDS.VizieR/J/A+A/636/A97
- Title:
- SDSS-IV/SPIDERS X-ray PS Spectroscopic Catalog
- Short Name:
- J/A+A/636/A97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We look to provide a detailed description of the SPectroscopic IDentification of ERosita Sources (SPIDERS) survey, an SDSS-IV programme aimed at obtaining spectroscopic classification and redshift measurements for complete samples of sufficiently bright X-ray sources. We describe the SPIDERS X-ray Point Source Spectroscopic Catalogue, considering its store of 11092 observed spectra drawn from a parent sample of 14759 ROSAT and XMM sources over an area of 5129deg^2^ covered in SDSS-IV by the eBOSS survey. This programme represents the largest systematic spectroscopic observation of an X-ray selected sample. A total of 10970 (98.9%) of the observed objects are classified and 10849 (97.8%) have secure redshifts. The majority of the spectra (10070 objects) are active galactic nuclei (AGN), 522 are cluster galaxies, and 294 are stars. The observed AGN redshift distribution is in good agreement with simulations based on empirical models for AGN activation and duty cycle. Forming composite spectra of type 1 AGN as a function of the mass and accretion rate of their black holes reveals systematic differences in the H-beta emission line profiles. This study paves the way for systematic spectroscopic observations of sources that are potentially to be discovered in the upcoming eROSITA survey over a large section of the sky.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/201/10
- Title:
- SDSS quasar catalog with Swift observations
- Short Name:
- J/ApJS/201/10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled a catalog of optically selected quasars with simultaneous observations in UV/optical and X-ray bands by the Swift Gamma-ray Burst Explorer. Objects in this catalog are identified by matching the Swift pointings with the Sloan Digital Sky Survey Data Release 5 quasar catalog. The final catalog contains 843 objects, among which 637 have both Ultraviolet Optical Telescope (UVOT) and X-Ray Telescope (XRT) observations and 354 of which are detected by both instruments. The overall X-ray detection rate is ~60% which rises to ~85% among sources with at least 10ks of XRT exposure time. We construct the time-averaged spectral energy distribution (SED) for each of the 354 quasars using UVOT photometric measurements and XRT spectra. From model fits to these SEDs, we find that the big blue bump contributes about ~0.3 dex to the quasar luminosity. We re-visit the {alpha}_ox_-L_2500_{AA} relation by selecting a clean sample with only Type 1 radio-quiet quasars; the dispersion of this relation is reduced by at least 15% compared with studies that use non-simultaneous UV/optical and X-ray data.
823. SDSS-ROSAT AGN data
- ID:
- ivo://CDS.VizieR/J/AJ/130/387
- Title:
- SDSS-ROSAT AGN data
- Short Name:
- J/AJ/130/387
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a sample of 228 optically selected active galactic nuclei (AGNs) in the 0.01-6.3 redshift range with a high fraction of X-ray detections (81%-86%), we study the relation between rest-frame UV and soft X-ray emission and its evolution with cosmic time. The majority of the AGNs in our sample (155 objects) have been selected from the Sloan Digital Sky Survey (SDSS) in an unbiased way, rendering the sample results representative of all SDSS AGNs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/2551
- Title:
- SDSS/3XMM X-ray-selected LINERs
- Short Name:
- J/MNRAS/455/2551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A sample of 576 X-ray-selected LINERs was constructed by combining data from the 3XMM-DR4 and SDSS-DR7 catalogues. The sample was used to investigate the fraction of galaxies hosting a LINER, finding that the fraction is a strong function of both stellar mass and black hole mass (increasing as f_LINER_{prop.to}M*^1.6+/-0.2^ and f_LINER_{propto}M_BH_^0.6+/-0.1^, respectively) and that it rises close to unity at the highest black hole masses and lowest X-ray luminosities. After obtaining radio flux densities from the FIRST survey, the sample was also used to investigate the Fundamental Plane of black hole activity - a scale-invariant relationship between black hole mass, X-ray luminosity and radio luminosity that is believed to hold across at least nine orders of magnitude of mass. There are key advantages in using only LINERs for the derivation as these are the counterparts of the 'low-hard' X-ray binaries for which the relationship is tightest. The Fundamental Plane was found to be log(L_R_/(erg/s)) = 0.65(+/-0.07)log(L_X_/(10^42^erg/s)) + 0.69(+/-0.10)log(M_BH_/10^8^M_{sun}_) + 38.35(+/-0.10). The scatter around the plane was 0.73+/-0.03dex, too large to suggest that the Fundamental Plane can be used as a tool to estimate black hole mass from the observables of X-ray and radio luminosity. The black hole mass scaling is sensitive to the slope of the mass - velocity dispersion relation and, in order to achieve consistency with X-ray binaries, the analysis favours a steep gradient for this relationship, as found in recent research.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/1
- Title:
- SEAMBHs. XI. Mrk 142 X-ray to optical light curves
- Short Name:
- J/ApJ/896/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We performed an intensive accretion disk reverberation mapping campaign on the high accretion rate active galactic nucleus Mrk142 in early 2019. Mrk 142 was monitored with the Neil Gehrels Swift Observatory for four months in X-rays and six different UV/optical filters. Ground-based photometric monitoring was obtained from the Las Cumbres Observatory, the Liverpool Telescope, and the Dan Zowada Memorial Observatory in ugriz filters, as well as from the Yunnan Astronomical Observatory in V. Mrk 142 was highly variable throughout, displaying correlated variability across all wavelengths. We measure significant time lags between the different wavelength lightcurves. In the UV and optical, we find that the wavelength-dependent lags, {tau}({lambda}), generally follow the relation {tau}({lambda}){propto}{lambda}^4/3^, as expected for the T{propto}R^-3/4^ profile of a steady-state, optically thick, geometrically thin accretion disk, though they can also be fit by {tau}({lambda}){propto}{lambda}^2^, as expected for a slim disk. The exceptions are the u and U bands, where an excess lag is observed, as has been observed in other active galactic nuclei and attributed to continuum emission arising in the broad-line region. Furthermore, we perform a flux-flux analysis to separate the constant and variable components of the spectral energy distribution, finding that the flux dependence of the variable component is consistent with the f{nu}{propto}{nu}^1/3^ spectrum expected for a geometrically thin accretion disk. Moreover, the X-ray to UV lag is significantly offset from an extrapolation of the UV/optical trend, with the X-rays showing a poorer correlation with the UV than the UV does with the optical. The magnitude of the UV/optical lags is consistent with a highly super-Eddington accretion rate.
- ID:
- ivo://CDS.VizieR/J/A+A/460/695
- Title:
- Search for Associations Containing Young stars
- Short Name:
- J/A+A/460/695
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report results from a high-resolution optical spectroscopic survey aimed to search for nearby young associations and young stars among optical counterparts of ROSAT All-Sky Survey (<IX/10> and <IX/29>, X-ray sources in the Southern Hemisphere. We selected 1953 late-type (B-V>=0.6), potentially young, optical counterparts out of a total of 9574 1RXS sources for follow-up observations. At least one high-resolution spectrum was obtained for each of 1511 targets. This paper is the first in a series presenting the results of the SACY survey. Here we describe our sample and our observations. We describe a convergence method in the (UVW) velocity space to find associations. As an example, we discuss the validity of this method in the framework of the Beta Pic Association.
- ID:
- ivo://CDS.VizieR/IX/2
- Title:
- Second Ariel X-Ray Catalogue (2A)
- Short Name:
- IX/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains 107 sources in the energy range 2-18 keV, galactic latitude |b|>10{deg}. It results from the sky survey conducted by the Leiscester Sky Survey Instrument on Ariel V. The file "2a.dat" is the electronic version of the table 1 of the original paper, prepared by G. Share (Naval Research Laboratory). It contains 2 sources more than the original paper.
- ID:
- ivo://CDS.VizieR/IX/8
- Title:
- Second Catalogue of X-ray Sources
- Short Name:
- IX/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of X-ray sources containing 677 objects known as of 1979 September. X-ray data for 677 sources are the result of X-ray sky surveys by rockets, balloons, and satellites during 1964-1979. The sky survey is practically complete to X-ray intensities of nearly 4 micro-Jy in the 2-6 keV range. The current version does not include the investigation by HEAO 2. The catalog includes source names, positions of the maximum probability densities, date of the measurements, the type of measuring systems, the ranges at which the measurement was performed, maximum intensities for constant sources, and ratio of the maximum observed value of intensity to the minimum one for variable sources. The catalog is an update of the publication, by the same authors, in 1979ApJS...41..327A
- ID:
- ivo://CDS.VizieR/J/ApJ/662/224
- Title:
- Second CIZA subsample
- Short Name:
- J/ApJ/662/224
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the latest results of the Clusters in the Zone of Avoidance (CIZA) survey, which is mapping large-scale structures behind the Milky Way by performing the first systematic search for galaxy clusters at low Galactic latitudes. The survey's approach, which uses X-ray emission to locate cluster candidates, minimizes the problems faced by optically selected cluster surveys, which have traditionally avoided this region of the sky due to the severe extinction present along the Galactic plane. We here present the second flux-limited CIZA cluster catalog, containing 57 X-ray-selected galaxy clusters, of which 88% are new discoveries. We use this sample to examine the degree to which known large-scale structures extend into the zone of avoidance and highlight newly discovered structures that have previously gone unnoticed.
- ID:
- ivo://CDS.VizieR/IX/35
- Title:
- Second EUVE Catalogues
- Short Name:
- IX/35
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Extreme Ultraviolet Explorer satellite was launched on June 7, 1992 from Cape Canaveral, Florida on a Delta II rocket. The payload contains three EUV scanning telescopes equipped with imaging detectors as well as a Deep Survey Spectrometer instrument which divides the light from a fourth telescope between an imaging detector and three EUV spectrometers. The wavelength range is 10-60nm, corresponding to an energy range of 20-120eV, in the 4 bands: 10nm : Lexan/Boron, 58-174{AA}, 89{AA}peak DS: Lexan/Boron, 67-178{AA}, 91{AA}peak (Deep Survey) 20nm : Al/Ti/C, 156-234{AA}, 171{AA}peak DS: Al/C, 157-364{AA}, 171{AA}peak (Deep Survey) 40nm : Ti/Sb/Ti/Al, 368-590{AA}, 405{AA}peak 60nm : Sn/SiO, 519-742{AA}, 555{AA}peak More details about the EUVE performances may be found in the paper by Sirk et al. (1997ApJS..110..347S) The EUVE Source Catalog published in 1996 paper is made of three source tables, plus a list of associations for each table: - survey.dat lists the 514 objects detected during the all-sky survey. - deepsurv.dat lists the 35 sources detected by the deep survey of half the ecliptic plane; three deep survey objects are also detected in the all-sky survey. - detect.dat lists 188 sources that have been detected in other ways, principally by deep exposures with the scanner telescopes as part of the Right Angle Program through 24 December 1994 (later RAP detections are reported in the 1999 paper) The corresponding association tables are idsurvey, iddeepsu.dat and iddetect.dat respectively, in which one EUVE source may by associated to 0, one or more counterparts. In nearly all cases the associated objects lie within 1arcmin of the actual source position. The all-sky catalog of faint EUV sources published in 1997 lists the faint sources detected jointly by EUVE and ROSAT WFC. The 1999 paper lists the detections made from the observations since the first EUVE RAP catalog (1994 January) and covers 17% of the sky.