J/A+A/708/A56 Accretion and jet radiation mechanisms (Ye+, 2026)
Linking Fermi blazars and radio galaxies through accretion and jet radiation
mechanisms.
Ye X.-H., Baldi R.D., Yang W.-X., Zhu J.-T., Bastieri D., Bachev R.S.,
Strigachev A.A., Fan J.-H.
<Astron. Astrophys. 708, A56 (2026)>
=2026A&A...708A..56Y 2026A&A...708A..56Y (SIMBAD/NED BibCode)
ADC_Keywords: BL Lac objects; Galaxies, radio ; Accretion
Keywords: radiation mechanisms: non-thermal - galaxies: active -
BL Lacertae objects: general - galaxies: jets
Abstract:
Based on the classical unification, blazars, namely BL Lacertae
objects (BL Lacs) and flat-spectrum radio quasars (FSRQs), are
believed to correspond with radio galaxies when observed at small jet
viewing angles.
In this paper, we aim to compile a sample of Fermi blazars [redshift,
z∈(0.002-4.313)] and radio galaxies [z∈(0.001-1.048)] to
provide new insights towards a unified accretion and ejection scenario
between aligned and misaligned radio-loud active galactic nuclei
(AGNs), by considering their optical emission-line classifications
(low- and high-excitation radio galaxies, LERGs, HERGs), which are
more representative of their accretion states.
We adopted statistical analyses of accretion properties and
high-energy beaming patterns for both Fermi blazars and radio galaxies
to investigate a unified accretion-ejection scenario. In the
gamma-ray luminosity-photon index plane, HERGs populate the region
of higher luminosities and softer photon indices, akin to FSRQs,
whereas LERGs occupy lower luminosities with harder photon indices,
analogous to BL Lacs. This parallel segregation indicates that LERGs
and HERGs represent the misaligned counterparts of BL Lacs and FSRQs,
respectively. The unified picture is further supported by the Compton
dominance-photon index diagram, where FSRQs and HERGs dominated by
external Compton (EC) emissions are distinctly separated from BL Lacs
and LERGs governed by synchrotron self-Compton (SSC) emissions.
Similarly, the diagram of accretion rate versus gamma-ray photon index
reveals two distinct accretion-ejection states: a low-accretion-rate
branch (BL Lacs and LERGs) associated with the SSC model, and a
high-accretion-rate branch (FSRQs and HERGs) linked to the EC model.
These results strongly support a unified accretion and ejection
paradigm between blazars and radio galaxies into two distinct states.
Description:
Table 1 presents the basic physical parameters for 1622 Fermi blazars
used in this work.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 61 1621 Physical parameters of Fermi blazars
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See also:
IX/67 : Incremental Fermi LAT 4th cat. (4FGL-DR3)
(Fermi-LAT col., 2022)
J/ApJS/253/46 : Optical spectroscopy of Fermi blazars (Paliya+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- 4FGL 4FGL source name (JHHMM.m+DDMM)
14- 18 F5.3 --- z Redshift
20- 25 A6 --- Class Classification
27- 30 F4.2 --- Gammagamma gamma-ray photon index
32- 36 F5.2 [10-7W] logLgamma Logarithm of gamma-ray luminosity
(in erg/s)
38- 43 F6.2 [10-7W] logLbol ? Logarithm of bolometric luminosity
(in erg/s)
45- 51 F7.2 --- CD ? Compton dominance
53- 57 F5.2 --- log(Lbol/Lgamma) ? Accretion rate
59- 61 A3 --- Ref [P21 ] Reference for both the Compton
dominance and the accretion rate (1)
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Note (1): Reference as follows:
P21 = Paliya et al., 2021ApJS..253...46P 2021ApJS..253...46P, Cat. J/ApJS/253/46
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Acknowledgements:
Xu-Hong Ye, xuhong.ye(at)phd.unipd.it
(End) Patricia Vannier [CDS] 16-Feb-2026