J/ApJ/893/L20 Proton synchrotron gamma-rays in blazars (Liodakis+, 2020)
Proton synchrotron gamma-rays and the energy crisis in blazars.
Liodakis I., Petropoulou M.
<Astrophys. J., 893, L20 (2020)>
=2020ApJ...893L..20L 2020ApJ...893L..20L (SIMBAD/NED BibCode)
ADC_Keywords: Gamma rays ; Active gal. nuclei ; BL Lac objects ; Magnetic fields
Keywords: blazars - relativistic jets - radiative processes -
non-thermal radiation sources - neutrino astronomy -
supermassive black holes - black hole physics
Abstract:
The origin of high-energy emission in blazars jets (i.e., leptonic
versus hadronic) has been a longstanding matter of debate. Here, we
focus on one variant of hadronic models where proton synchrotron
radiation accounts for the observed steady γ-ray blazar
emission. Using analytical methods, we derive the minimum jet power
(Pj,min) for the largest blazar sample analyzed to date (145
sources), taking into account uncertainties of observables and jet's
physical parameters. We compare Pj,min against three characteristic
energy estimators for accreting systems, i.e., the Eddington
luminosity, the accretion disk luminosity, and the power of the
Blandford-Znajek process, and find that Pj,min is about 2 orders of
magnitude higher than all energetic estimators for the majority of our
sample. The derived magnetic field strengths in the emission region
require either large amplification of the jet's magnetic field (factor
of 30) or place the γ-ray production site at sub-pc scales. The
expected neutrino emission peaks at ∼0.1-10EeV, with typical peak
neutrino fluxes ∼10-4 times lower than the peak γ-ray fluxes.
We conclude that if relativistic hadrons are present in blazar jets,
they can only produce a radiatively subdominant component of the
overall spectral energy distribution of the blazar's steady emission.
Description:
Parameter estimates for the sources in our sample.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 150 145 Parameter estimates for the sources in our sample
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Name Name (4FGLJHHMM.m+DDMM)
18- 28 A11 --- Oname Alternative name
30- 36 F7.4 GeV Eh Peak energy of high energy component
38- 42 F5.2 [10-7W] logLumh Peak luminosity of high energy component
(erg/s)
44- 50 F7.2 gauss Bem Magnetic field strength
52- 58 F7.2 gauss E_Bem Upper uncertainty on
magnetic field strength
60- 66 F7.2 gauss e_Bem Lower uncertainty on
magnetic field strength
68- 72 F5.2 [10-7W] logPjmin Minimum jet power, erg/s
74- 78 F5.2 [10-7W] E_logPjmin Upper uncertainty on minimum jet power
(erg/s)
80- 83 F4.2 [10-7W] e_logPjmin Lower uncertainty on minimum jet power
(erg/s)
85- 88 F4.2 [Msun] logMBH ? Black hole mass, solar units
90- 93 F4.2 [Msun] e_logMBH ? Uncertainty on black hole mass
95- 99 F5.2 [10-7W] logLumd ? Accretion disk luminosity (erg/s)
101-104 F4.2 [10-7W] e_logLumd ? Uncertainty on accretion disk luminosity
(erg/s)
106-110 F5.2 [10-7W] logPBZ Blandford-Znajek jet power (erg/s)
112 I1 --- f_logPBZ [1/2] Type of Blandford-Znajek jet power
estimate (1)
114-117 F4.2 [10-7W] e_logPBZ Uncertainty on Blandford-Znajek jet power
(erg/s)
119-122 F4.2 [TeV] logEpk Peak energy of muon neutrinos
124-127 F4.2 [TeV] E_logEpk Upper uncertainty on peak energy of
muon neutrinos
129-132 F4.2 [TeV] e_logEpk Lower uncertainty on peak energy of
muon neutrinos
134-139 F6.2 [TeV/cm2/s] logFpk Peak flux of muon neutrinos
141-145 F5.2 [TeV/cm2/s] E_logFpk Upper uncertainty on peak flux of
muon neutrinos
147-150 F4.2 [TeV/cm2/s] e_logFpk Lower uncertainty on peak flux of
muon neutrinos
--------------------------------------------------------------------------------
Note (1): Type of Blandford-Znajek jet power estimate as follows:
1 = estimate derived from core-shift measurements
2 = estimate derived without core-shift measurement
--------------------------------------------------------------------------------
Acknowledgements:
Ioannis Liodakis, ilioda(at)stanford.edu
(End) I. Liodakis [KIPAC, Stanford Univ. USA], P. Vannier [CDS] 29-Apr-2020