- 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.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/652/A59
- Title:
- SDSS Solar System Objects
- Short Name:
- J/A+A/652/A59
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The populations of small bodies of the Solar System (asteroids, comets, Kuiper-Belt objects) are used to constrain the origin and evolution of the Solar System. Both their orbital distribution and composition distribution are required to track the dynamical pathway from their regions of formation to their current locations. We aim at increasing the sample of Solar System objects that have multi-filter photometry and compositional taxonomy. We search for moving objects in the archive of the Sloan Digital Sky Survey. We attempt at maximizing the number of detections by using loose constraints on the extraction. We then apply a suite of filters to remove false-positive detections (stars or galaxies) and mark out spurious photometry and astrometry. We release a catalog of 1542522 entries, consisting of 1036322 observations of 379714 known and unique SSOs together with 506200 observations of moving sources not linked with any known SSOs. The catalog completeness is estimated to be about 95% and the purity to be above 95% for known SSOs.
- ID:
- ivo://CDS.VizieR/J/ApJS/253/20
- Title:
- SEAMBHs XII. Reberberation mapping for 15 PG QSOs
- Short Name:
- J/ApJS/253/20
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we present the first results of the long-term high-cadence spectroscopic monitoring of 15 PG quasars with relatively strong FeII emission, as a part of a broader reverberation mapping campaign performed using the Calar Alto Observatory's 2.2m telescope. The V-band, 5100{AA} continuum, and H{beta} broad emission line light curves are measured for a set of quasars for periods ranging from dozens to more than a hundred epochs between 2017 May and 2020 July. Accurate time lags between the variations of the H{beta} broad-line fluxes and the optical continuum strength are obtained for all 15 quasars, ranging from 17.0_-3.2_^+2.5^ to 95.9_-23.9_^+7.1^ days in the rest frame. The virial masses of the central supermassive black holes are derived for all 15 quasars, ranging between 0.50_-0.19_^+0.18^ and 19.17_-2.73_^+2.98^ in units of 10^7^M_{sun}_. For 11 of the objects in our sample, this is the first reverberation analysis to be published. Of the rest, two objects have been the subject of previous reverberation studies, but we determine time lags for these that are only half as long as those found in the earlier investigations, which had only been able to sample much more sparsely. The remaining two objects have previously been monitored with high sampling rates. Our results here are consistent with the earlier findings, in the sense that the time lag and the line width vary inversely, consistent with virialization.
- 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/J/A+AS/146/169
- Title:
- Secondary UBVRI-CCD standard stars
- Short Name:
- J/A+AS/146/169
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Table 4 contains astrometric (alpha, delta) and photometric (UBVRI) data for 681 secondary standard stars in the neighbourhood of several Landolt standard stars. Several columns contain information related to the origin and quality of the photometry. Cross-identifications with USNO-A2.0 catalogue (<I/252>) are given. Further cross-identifications are given in notes.
- ID:
- ivo://CDS.VizieR/J/ApJ/716/30
- Title:
- SED of Fermi bright blazars
- Short Name:
- J/ApJ/716/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have conducted a detailed investigation of the broadband spectral properties of the {gamma}-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS, Cat. J/ApJ/700/597). By combining our accurately estimated Fermi {gamma}-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/{gamma}-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, {alpha}_ro_, and optical to X-ray, {alpha}_ox_, spectral slopes) and from the {gamma}-ray spectral index. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are detected in the LBAS sample, only less than 13% of known bright broad-lined flat spectrum radio quasars (FSRQs) and LBL BL Lacs are included. This suggests that the latter sources, as a class, may be much fainter {gamma}-ray emitters than LBAS blazars, and could in fact radiate close to the expectations of simple synchrotron self-Compton (SSC) models. We categorized all our sources according to a new physical classification scheme based on the generally accepted paradigm for Active Galactic Nuclei and on the results of this SED study.
- ID:
- ivo://CDS.VizieR/J/ApJ/729/22
- Title:
- SEDs of galaxy cluster members
- Short Name:
- J/ApJ/729/22
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a study of AGNs and their host galaxies found in low-redshift galaxy clusters. We fit model spectral energy distributions (SEDs) to the combined visible and mid-infrared (MIR) photometry of cluster members and use these model SEDs to determine stellar masses and star formation rates (SFRs). We identify two populations of AGNs, the first based on their X-ray luminosities (X-ray AGNs) and the second based on the presence of a significant AGN component in their model SEDs (IR AGNs). We find that the two AGN populations are nearly disjoint; only 8 out of 44 AGNs are identified with both techniques.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/11
- Title:
- SEDs of Spitzer YSOs in the Gould Belt
- Short Name:
- J/ApJS/220/11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the full catalog of Young Stellar Objects (YSOs) identified in the 18 molecular clouds surveyed by the Spitzer Space Telescope "cores to disks" (c2d) and "Gould Belt" (GB) Legacy surveys. Using standard techniques developed by the c2d project, we identify 3239 candidate YSOs in the 18 clouds, 2966 of which survive visual inspection and form our final catalog of YSOs in the GB. We compile extinction corrected spectral energy distributions for all 2966 YSOs and calculate and tabulate the infrared spectral index, bolometric luminosity, and bolometric temperature for each object. We find that 326 (11%), 210 (7%), 1248 (42%), and 1182 (40%) are classified as Class 0+I, Flat-spectrum, Class II, and Class III, respectively, and show that the Class III sample suffers from an overall contamination rate by background Asymptotic Giant Branch stars between 25% and 90%. Adopting standard assumptions, we derive durations of 0.40-0.78Myr for Class 0+I YSOs and 0.26-0.50Myr for Flat-spectrum YSOs, where the ranges encompass uncertainties in the adopted assumptions. Including information from (sub)millimeter wavelengths, one-third of the Class 0+I sample is classified as Class 0, leading to durations of 0.13-0.26Myr (Class 0) and 0.27-0.52Myr (Class I). We revisit infrared color-color diagrams used in the literature to classify YSOs and propose minor revisions to classification boundaries in these diagrams. Finally, we show that the bolometric temperature is a poor discriminator between Class II and Class III YSOs.
- ID:
- ivo://CDS.VizieR/J/ApJ/759/6
- Title:
- SEDs of type I AGN in COSMOS. I. XMM-COSMOS
- Short Name:
- J/ApJ/759/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The "Cosmic Evolution Survey" (COSMOS) enables the study of the spectral energy distributions (SEDs) of active galactic nuclei (AGNs) because of the deep coverage and rich sampling of frequencies from X-ray to radio. Here we present an SED catalog of 413 X-ray (XMM-Newton)-selected type 1 (emission line FWHM>2000km/s) AGNs with Magellan, SDSS, or VLT spectrum. The SEDs are corrected for Galactic extinction, broad emission line contributions, constrained variability, and host galaxy contribution. We present the mean SED and the dispersion SEDs after the above corrections in the rest-frame 1.4GHz to 40keV, and show examples of the variety of SEDs encountered. In the near-infrared to optical (rest frame ~8{mu}m-4000{AA}), the photometry is complete for the whole sample and the mean SED is derived from detections only. Reddening and host galaxy contamination could account for a large fraction of the observed SED variety.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A63
- Title:
- Semi-sinusoidal variability with CoRoT
- Short Name:
- J/A+A/555/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To date, the CoRoT space mission has produced more than 124471 light curves. Classifying these curves in terms of unambiguous variability behavior is mandatory for obtaining an unbiased statistical view on their controlling root-causes. The present study provides an overview of semi-sinusoidal light curves observed by the CoRoT exo-field CCDs. We selected a sample of 4206 light curves presenting well-defined semi-sinusoidal signatures. The variability periods were computed based on Lomb-Scargle periodograms, harmonic fits, and visual inspection.
