CONSTRAINTS ON THE MINIMUM ELECTRON LORENTZ FACTOR AND MATTER CONTENT OF JETS FOR A SAMPLE OF BRIGHT FERMI BLAZARS

Journal Article · Sat Nov 01 04:00:00 EDT 2014 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/215/1/5· OSTI ID:22340143

Kang, Shi-Ju; Wu, Qingwen ^[1]; Chen, Liang ^[2]

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1. School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)
2. Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

We fit (quasi-)simultaneous multi-waveband spectral energy distributions for a sample of low-synchrotron-peaked (LSP) blazars with a one-zone leptonic model. The seed photons that predominantly come from the broad line region (BLR) and infrared (IR) molecular torus are considered in the context of an external Compton process. We find that modeling with IR seed photons is systematically better than that with BLR photons based on a χ{sup 2} test, which suggests that γ-ray-emitting regions are most likely found outside the BLR. The minimum electron Lorentz factor, γ{sub min}, is constrained from the modeling of these LSP blazars with good soft X-ray data (ranging from 5 to 160 with a median value of 55), which plays a key role in jet power estimation. Assuming a one-to-one ratio of protons to electrons, we find that the jet power for LSP blazars is systematically higher than that of FR II radio galaxies at a 151 MHz radio luminosity, L {sub 151} {sub MHz} even though FR IIs are regarded as the same as LSP blazars in a unification scheme except at the jet viewing angle. A possible reason for this is that there are some e {sup ±} pairs in the jets of these blazars. If this is the case, we find that the number density of e {sup ±} pairs should be several times higher than that of e {sup –}-p pairs by assuming the jet power is the same for LSP blazars and FR IIs at the given L {sub 151} {sub MHz}.

• OSTI ID: 22340143
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 1 Vol. 215; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BL LACERTAE OBJECTS
ELECTRONS
ENERGY SPECTRA
JETS
LIMITING VALUES
LORENTZ TRANSFORMATIONS
LUMINOSITY
MHZ RANGE
PAIR PRODUCTION
PHOTONS
PROTONS
QUASARS
RADIO GALAXIES
SOFT X RADIATION