TY - JOUR
T1 - The Lx-Luv-Lradio relation and corona-disc-jet connection in optically selected radio-loud quasars
AU - Zhu, S. F.
AU - Brandt, W. N.
AU - Luo, B.
AU - Wu, Jianfeng
AU - Xue, Y. Q.
AU - Yang, G.
N1 - Funding Information:
We appreciate the help of Mark Lacy in measuring the VLA Sky Survey fluxes. We thank Tracy Clarke for her effort in checking the VLA Low-band Ionosphere and Transient Experiment data of our radio-loud quasars. We thank Ari Laor for his comments that greatly improved the clarity of this paper. We also have benefitted from the help of Brendan Miller and discussions with Mike Eracleous. We thank the referee, Giovanni Zamorani, for his constructive review. SFZ and WNB acknowledge support from CXC grant AR8-19011X, NASA ADAP grant 80NSSC18K0878, and the Penn State ACIS Instrument Team Contract SV4-74018 (issued by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060). The Chandra ACIS team Guaranteed Time Observations (GTO) utilized were selected by the ACIS Instrument Principal Investigator, Gordon P. Garmire, currently of the Huntingdon Institute for X-ray Astronomy, LLC, which is under contract to the Smithsonian Astrophysical Observatory via Contract SV2-82024. BL acknowledges financial support from the National Natural Science Foundation of China grants 11673010 and 11991053 and National Key R&D Program of China grant 2016YFA0400702. YQX acknowledges support from NSFC-11890693, NSFC-11421303, the CAS Frontier Science Key Research Program (QYZDJ-SSW-SLH006), and the K.C. Wong Education Foundation. This research has made use of data obtained from the Chandra Data Archive and the Chandra Source Catalog. Based on observations obtained with XMM–Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA.
Publisher Copyright:
© 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2020/6/11
Y1 - 2020/6/11
N2 - Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray-optical/UV relation (i.e. L Lγ) for radio-quiet quasars (RQQs). The excess X-ray emission depends on the radio-loudness parameter (R) and radio spectral slope (αr). We construct a uniform sample of 729 optically selected RLQs with high fractions of X-ray detections and αr measurements. We find that steep-spectrum radio quasars (SSRQs; αr ≤-0.5) follow a quantitatively similar L Lγ relation as that for RQQs, suggesting a common coronal origin for the X-ray emission of both SSRQs and RQQs. However, the corresponding intercept of SSRQs is larger than that for RQQs and increases with R, suggesting a connection between the radio jets and the configuration of the accretion flow. Flat-spectrum radio quasars (FSRQs; αr >-0.5) are generally more X-ray luminous than SSRQs at given Luv and R, likely involving more physical processes. The emergent picture is different from that commonly assumed where the excess X-ray emission of RLQs is attributed to the jets. We thus perform model selection to compare critically these different interpretations, which prefers the coronal scenario with a corona-jet connection. A distinct jet component is likely important for only a small portion of FSRQs. The corona-jet, disc-corona, and disc-jet connections of RLQs are likely driven by independent physical processes. Furthermore, the corona-jet connection implies that small-scale processes in the vicinity of supermassive black holes, probably associated with the magnetic flux/topology instead of black hole spin, are controlling the radio-loudness of quasars.
AB - Radio-loud quasars (RLQs) are more X-ray luminous than predicted by the X-ray-optical/UV relation (i.e. L Lγ) for radio-quiet quasars (RQQs). The excess X-ray emission depends on the radio-loudness parameter (R) and radio spectral slope (αr). We construct a uniform sample of 729 optically selected RLQs with high fractions of X-ray detections and αr measurements. We find that steep-spectrum radio quasars (SSRQs; αr ≤-0.5) follow a quantitatively similar L Lγ relation as that for RQQs, suggesting a common coronal origin for the X-ray emission of both SSRQs and RQQs. However, the corresponding intercept of SSRQs is larger than that for RQQs and increases with R, suggesting a connection between the radio jets and the configuration of the accretion flow. Flat-spectrum radio quasars (FSRQs; αr >-0.5) are generally more X-ray luminous than SSRQs at given Luv and R, likely involving more physical processes. The emergent picture is different from that commonly assumed where the excess X-ray emission of RLQs is attributed to the jets. We thus perform model selection to compare critically these different interpretations, which prefers the coronal scenario with a corona-jet connection. A distinct jet component is likely important for only a small portion of FSRQs. The corona-jet, disc-corona, and disc-jet connections of RLQs are likely driven by independent physical processes. Furthermore, the corona-jet connection implies that small-scale processes in the vicinity of supermassive black holes, probably associated with the magnetic flux/topology instead of black hole spin, are controlling the radio-loudness of quasars.
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U2 - 10.1093/mnras/staa1411
DO - 10.1093/mnras/staa1411
M3 - Article
AN - SCOPUS:85088559995
SN - 0035-8711
VL - 496
SP - 245
EP - 268
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -