arXiv subjects

Dingrong Xiong

Publications and source records attributed to Dingrong Xiong.

40 records · Page 3Linked to original sources

arXiv2015

The jets-accretion relation, mass-luminosity relation in Fermi blazars

A sample of 111 Fermi blazars each with a well-established radio core luminosity, broad-line luminosity, bolometric luminosity and black hole mass has been compiled from the literatures.We present a significant correlation between radio core and broad-line emission luminosities that supports a close link between accretion processes and relativistic jets. Analysis reveals a relationship of $\rm{LogL_{BLR}\sim(0.81\pm0.06)LogL_{R}^{C}}$ which is consistant with theoretical predicted coefficient and supports that blazar jets are powered by energy extraction from a rapidly spinning Kerr black hole through the magnetic field provided by the accretion disk. Through studying the correlation between the intrinsic bolometric luminosity and the black hole mass, we find a relationship of $\rm{{Log}\frac{L_{in}}{L_{\odot}}=(0.95\pm0.26){Log}\frac{M}{M_{\odot}}+(3.53\pm2.24)}$ which supports mass-luminosity relation for Fermi blazars derived in this work is a powerlaw relation similar to that for main-sequence stars. Finally, evolutionary sequence of blazars is discussed.

astro-ph.HE↗

arXiv2015

Black hole mass, jet power and accretion in AGN

We study the relation between accretion, black hole mass and jet power in AGN, by using a large group of blazars detected by the Fermi Large Area Telescope and radio galaxies. Our main results are as follows. (i) The jet power of FSRQs and FRII-HEG depends on the black hole mass, which suggests that the FSRQs and FRII-HEG are in Radiation-Pressure Dominated regime. The jet power of BL Lacs and FRI-LEG depends on the accretion, which suggests that the BL Lacs and FRI-LEG are in the Gas-Pressure Dominated regime. (ii) We find that most of FSRQs and BL Lacs have $\rm{P_{jet}>L_{BZ}^{max}}$, which suggests that the Blandford-Znajek mechanism is insufficient to explain the jet power of these objects. (iii) The FSRQs are roughly separated from BL Lacs by the Ledlow-Owen's dividing line in the $\rm{\log P_{jet}-\log M}$ plane, which supports the unified scheme of AGN. (iv) The FSRQs and BL Lacs have a clear division at $\rm{L_{bol}/L_{Edd}\sim0.01}$, and the distribution of Eddington ratios of BL Lacs and FSRQs exhibits a bimodal nature, which imply that the accretion mode of FSRQs may be different from that of BL Lacs. (v) We find a significant correlation between broad line luminosity and jet power, which supports a direct tight connection between jet power and accretion.

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arXiv2015

Basic properties of Fermi blazars and the "blazar sequence"

By statistically analyzing a large sample which includes blazars of Fermi detection (FBs) and non-Fermi detection (NFBs), we find that there are significant differences between FBs and NFBs for redshift, black hole mass, jet kinetic power from "cavity" power, broad-line luminosity, and ratio of core luminosity to absolute V-band magnitude ($R_{\rm v}$), but not for ratio of radio core to extended flux ($R_{\rm c}$) and Eddington ratio. Compared with NFBs, FBs have larger mean jet power, $R_{\rm c}$ and $R_{\rm v}$ while smaller mean redshift, black hole mass, broad-line luminosity. These results support that the beaming effect is main reason for differences between FBs and NFBs, and that FBs are likely to have a more powerful jet. For both Fermi and non-Fermi blazars, there are significant correlations between jet power and the accretion rate (traced by the broad-emission-lines luminosity), between jet power and black hole mass; for Fermi blazars, the black hole mass does not have significant influence on jet power while for non-Fermi blazars, both accretion rate and black hole mass have contributions to the jet power. Our results support the "blazar sequence" and show that synchrotron peak frequency ($ν_{\rm peak}$) is associated with accretion rate but not with black hole mass.

astro-ph.HE↗

arXiv2014

Intrinsic $γ$-ray luminosity, black hole mass, jet and accretion in Fermi blazars

We have analyzed a large sample of clean blazars detected by Fermi Large Area Telescope (LAT). Using literature and calculation, we obtained intrinsic $γ$-ray luminosity excluding beaming effect, black hole mass, broad-line luminosity (used as a proxy for disk luminosity), jet kinetic power from "cavity" power and bulk Lorentz factor for parsec-scale radio emission, and studied the distributions of these parameters and relations between them. Our main results are as follows. (i) After excluding beaming effect and redshift effect, intrinsic $γ$-ray luminosity with broad line luminosity, black hole mass and Eddington ratio have significant correlations. Our results confirm the physical distinction between BL Lacs and FSRQs. (ii) The correlation between broad line luminosity and jet power is significant which supports that jet power has a close link with accretion. Jet power depends on both the Eddington ratio and black hole mass. We also obtain $LogL_{\rm BLR}\sim(0.98\pm0.07)Log P_{\rm jet}$ for all blazars, which is consistent with the theoretical predicted coefficient. These results support that jets are powered by energy extraction from both accretion and black hole spin (i.e., not by accretion only). (iii) For almost all BL Lacs, $P_{\rm jet}>L_{\rm disk}$; for most of FSRQs, $P_{\rm jet}<L_{\rm disk}$. The "jet-dominance" (parameterized as $\frac{P_{\rm jet}}{L_{\rm disk}}$) is mainly controlled by the bolometric luminosity. Finally, the radiative efficiency of $γ$-ray and properties of TeV blazars detected by Fermi LAT were discussed.

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