Fast γ-Ray Variability in Blazars beyond Redshift 3
Abstract
High-redshift blazars are one of the most powerful sources in the universe and γ-ray variability carries crucial information about their relativistic jets. In this work we present results of the first systematical temporal analysis of Fermi-LAT data of all known seven γ-ray blazars beyond redshift 3. Significant long-term γ-ray variability is found from five sources in monthly γ-ray light curves, in which three of them are reported for the first time. Furthermore, intraday γ-ray variations are detected from NVSS J053954-283956 and NVSS J080518+614423. The doubling variability timescale of the former source is limited as short as ≲1 hr (at the source frame). Together with variability amplitude over one order of magnitude, NVSS J053954-283956 is the most distant γ-ray flaring blazar so far. Meanwhile, intraday optical variability of NVSS J163547+362930 is found based on an archival PTF/iPTF light curve. Benefiting from the multi-wavelength activity of these sources, constraints on their Doppler factors, as well as the locations of the γ-ray radiation region and indications for the SDSS high redshift jetted active galactic nuclei deficit are discussed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 2018
- DOI:
- 10.3847/1538-4357/aaa3fb
- arXiv:
- arXiv:1710.02904
- Bibcode:
- 2018ApJ...853..159L
- Keywords:
-
- galaxies: active;
- galaxies: high-redshift;
- galaxies: jets;
- gamma rays: galaxies;
- quasars: general;
- radiation mechanisms: non-thermal;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 25 pages, 8 figures, 2 tables, ApJ in press