OSRILQXRAY - Optically Selected Radio-Intermediate and Loud Quasars X-ray Emission Catalog

Overview

This catalog contains some of the results of an investigation into the X-ray properties of radio-intermediate and radio-loud quasars (RIQs and RLQs, respectively). The authors have combined large, modern optical (e.g., SDSS) and radio (e.g., FIRST) surveys with archival X-ray data from Chandra, XMM-Newton, and ROSAT to generate an optically selected sample that includes 188 RIQs and 603 RLQs. This sample is constructed independently of X-ray properties but has a high X-ray detection rate (85%); it provides broad and dense coverage of the luminosity-redshift (l-z) plane, including at high redshifts (22% of the objects have z = 2-5), and it extends to high radio-loudness R_L values (33% of objects have R_L = log(L_r/L_o) = 3 - 5), where L_r and L_o are the rest-frame monochromatic luminosities at 5 GHz and 2500 Angstroms, respectively). The authors measure the "excess" X-ray luminosity of RIQs and RLQs relative to radio-quiet quasars (RQQs) as a function of radio loudness and luminosity, and parametrize the X-ray luminosity of RIQs and RLQs both as a function of optical/UV luminosity and also as a joint function of optical/UV and radio luminosity. RIQs are only modestly X-ray bright relative to RQQs; it is only at high values of radio loudness (R_L >~ 3.5) and radio luminosity that RLQs become strongly X-ray bright.

This HEASARC table contains the primary sample from the reference paper. The authors consider three categories of quasars in this work: RQQs, RIQs, and RLQs (rather than just RQQs and RLQs), where the define RIQs to consist of objects with 1 <= R_L < 2; consequently, the objects they classify as RLQs satisfy R_L >= 2. The primary sample contained herein consists of 654 optically selected RIQs and RLQs with SDSS/FIRST observations and high-quality X-ray coverage from Chandra (171), XMM-Newton (202), or ROSAT (281). The primary sample is split nearly evenly between spectroscopic (312) and high-confidence photometric (342) quasars. Most (562) of the primary sample objects possess serendipitous off-axis X-ray coverage, while the remainder (92) were targeted in the observations used in this sample. The X-ray detection fraction for the primary sample is 84%; the detection fraction for those objects with Chandra/XMM-Newton/ROSAT coverage is 95%/92%/70% (typical ROSAT observations are comparatively less sensitive and have higher background).

The authors adopt a standard cosmology with H₀ = 70 km s^-1 Mpc^-1, Omega_M = 0.3, and Omega_Lambda = 0.7 throughout their study.

Catalog Bibcode

2011ApJ...726...20M

References

X-ray emission from optically selected radio-intermediate and radio-loud
quasars.
    Miller B.P., Brandt W.N., Schneider D.P., Gibson R.R., Steffen A.T., Wu J.
   <Astrophys. J., 726, 20 (2011)>
   =2011ApJ...726...20M

Provenance

This table was created by the HEASARC in October 2012 based on CDS Catalog J/ApJ/726/20 file table1.dat.

Parameters

Name
The designation of the quasar as given in the SDSS DR5 for spectroscopic quasars or as in SDSS DR6 for photometric quasars, e.g., 'SDSS JHHMMSS.ss+DDMMSS.s'.

RA
The Right Ascension of the quasar in the selected equinox. This was constructed by the HEASARC from the name field and thus is based on the J2000.0 equatorial coordinate given to a (truncated) precision of 0.01 seconds of time.

Dec
The Declination of the quasar in the selected equinox. This was constructed by the HEASARC from the name field and thus is based on the J2000.0 equatorial coordinate given to a (truncated) precision of 0.1 arcseconds.

LII
The Galactic Longitude of the quasar.

BII
The Galactic Latitude of the quasar.

Redshift
The redshift of the quasar, spectroscopic if available from SDSS-DR5 or NED (such cases have sdss_flag = 'S'), otherwise photometric from the SDSS DR6 quasar catalog of Richards et al. (2009, ApJS, 180, 67: such cases have sdss_flag = 'P').

Imag
The SDSS PSF i-band magnitude of the quasar corrected for Galactic absorption.

Delta_Ig_Color
The (g-i) color of the quasar corrected for Galactic absorption minus the median SDSS quasar color at its redshift.

Log_LR
The logarithm of the monochromatic radio luminosity L_r of the quasar at (rest-frame) 5 GHz, in erg s^-1 Hz^-1. The radio luminosity L_r_is calculated from both core and lobe components as described in Section 3.2 of the reference paper, while the core radio luminosity L_(r,core) is for the core only.

Log_Lo
The logarithm of the monochromatic optical/UV luminosity L_o of the quasar at (rest-frame) 2500 Angstroms, in erg s^-1 Hz^-1.

Log_Lx_Limit
This flag parameter is set to '<' if the quasar was not X-ray detected, i.e., the quoted X-ray luminosity is a 95% confidence upper limit rather than a detection.

Log_Lx
The logarithm of the monochromatic X-ray luminosity L_x of the quasar at (rest-frame) 2 keV, in erg s^-1 Hz^-1.

Log_Lr_Lo
The radio loudness R_L of the quasar, defined as R_L = log(L_r/L_o), where L_r and L_o are the quasar's rest-frame monochromatic luminosities at 5 GHz and 2500 Angstroms, respectively

Alpha_Ox_Limit
This flag parameter is set to '<' if the quasar was not X-ray detected, i.e., the quoted X-ray luminosity is a 95% confidence upper limit rather than a detection.

Alpha_Ox
The optical/UV-to-X-ray slope of the spectrum of the quasar defined as alpha_ox = 0.384 * log(L_x/L_o).

Alpha_R
The radio spectral slope of the quasar, alpha_r, calculated between 1.4 and 5 GHz where Green Bank fluxes are available, and otherwise based on low-frequency (Texas and Westerbork) surveys; zero-valued entries indicate a lack of multi-frequency radio data.

Log_Lr_Core_Limit
This flag parameter is set to '<' to indicates that the core is not in the FIRST catalog, else is left blank. The upper limits for the core radio luminosities are calculated assuming 1 mJy upper limits to the 1.4-GHz flux densities in such cases.

Log_Lr_Core
The logarithm of the core radio luminosity L_(r,core) of the quasar at (rest-frame) 5 GHz, in erg s^-1 Hz^-1.

SDSS_Flag
This flag parameter indicates the source of the redshift for the quasar: 'S' means spectroscopic, i.e., taken from the SDSS-DR5 or NED, 'P' means photometric, i.e., taken from the SDSS DR6 quasar catalog of Richards et al. (2009, ApJS, 180, 67).

Xray_Obs_Flag
This parameter indicates the source of the X-ray data for the quasar:

      C = taken from the Chandra Source Catalog;
      X = taken from the XMM-Newton Serendipitous Catalog;
      CO= taken from the authors' own Chandra measurement;
      XO= taken from the authors' own XMM-Newton measurement;
      RO= taken from the authors' own ROSAT measurement.

Contact Person

Questions regarding the OSRILQXRAY database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:32:42 EDT