2017MNRAS.470.2861S


C.D.S. - SIMBAD4 rel 1.7 - 2019.12.16CET10:51:50

2017MNRAS.470.2861S - Mon. Not. R. Astron. Soc., 470, 2861-2869 (2017/September-3)

High energy gamma-ray emission from PKS 1441+25.

SAHAKYAN N. and GASPARYAN S.

Abstract (from CDS):

We present the γ-ray observations of the flat-spectrum radio quasar PKS 1441+25 (z = 0.939), using the Fermi large Area Telescope data accumulated during 2015 January - December. A γ-ray flare was observed in January 24, when the flux increased up to (2.22 ± 0.38) x 10–6 photon cm–2 s–1 with the flux-doubling time-scale being as short as ∼1.44 d. The spectral analysis shows that from 2015 April 13 to April 28, the MeV-to-GeV photon index has hardened and changes in the range of Γ = (1.73 - 1.79) for most of the time. The hardest photon index of Γ = 1.54 ± 0.16 has been observed on MJD 57 131.46 with 11.8σ which is not common for flat-spectrum radio quasars. For the same period the γ-ray spectrum shows a possible deviation from a simple power-law shape, indicating a spectral cutoff at Ecut = 17.7 ± 8.9 GeV. The spectral energy distributions during quiescent and flaring states are modelled using one-zone leptonic models that include the synchrotron, synchrotron self Compton and external inverse Compton processes; the model parameters are estimated using the Markov Chain Monte Carlo method. The emission in the flaring states can be modelled assuming that either the bulk Lorentz factor or the magnetic field has increased. The modelling shows that there is a hint of hardening of the low-energy index (∼1.98) of the underlying non-thermal distribution of electrons responsible for the emission in 2015 April. Such hardening agrees with the γ-ray data, which pointed out a significant γ-ray photon index hardening on 2015 April 13 to 28.

Abstract Copyright: © 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

Journal keyword(s): radiation mechanisms: non-thermal - galaxies: active - gamma-rays: galaxies - quasars: individual: PKS1441+25 - quasars: individual: PKS1441+25

Simbad objects: 7

goto Full paper

goto View the reference in ADS

Number of rows : 7

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 QSO B0218+357 QSO 02 21 05.5 +35 56 14   20.0 20.0 19.60   ~ 489 3
2 IC 310 rG 03 16 42.9787725062 +41 19 29.629862447   14.3       ~ 220 2
3 LB 2136 QSO 11 53 24.46663282 +49 31 08.8301947   17.94 17.66     ~ 410 1
4 ICRF J115354.6+403652 Sy1 11 53 54.6587375253 +40 36 52.622760681   19.68 19.36 20.2   ~ 52 1
5 7C 1441+2514 QSO 14 43 56.89219806 +25 01 44.4907918   19.5   19.7   ~ 90 1
6 QSO J1512-0906 QSO 15 12 50.53292491 -09 05 59.8295878   16.74 16.54     ~ 1124 1
7 QSO B2155-304 BLL 21 58 52.0651817803 -30 13 32.120657891   13.36 13.09 12.62   ~ 1523 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2017MNRAS.470.2861S and select 'bookmark this link' or equivalent in the popup menu


2019.12.16-10:51:50

© Université de Strasbourg/CNRS

    • Contact