89 research outputs found
VERITAS detection of gamma-ray flaring activity from the BL Lac object 1ES 1727+502 during bright moonlight observations
During May 2013, a gamma-ray flare from the BL Lac object 1ES 1727+502
(z=0.055) has been detected with the VERITAS Cherenkov telescopes. This
detection represents the first evidence of very-high-energy (E>100 GeV)
variability from this blazar and has been achieved using a reduced-high-voltage
configuration which allows observations under bright moonlight. The integral
flux is about five times higher than the archival VHE flux measured by MAGIC.
The detection triggered additional VERITAS observations during standard
dark-time and multiwavelength observations from infrared to X-rays with the
FLWO 48" telescope and the Swift satellite. The results from this campaign are
presented and used to produce the first spectral energy distribution of this
object during gamma-ray flaring activity. The spectral energy distribution is
then fit with a standard synchrotron-self-Compton model, placing constraints on
the properties of the emitting region in the blazar.Comment: 8 pages, 3 figures; to appear in the Proceedings of the 34th
International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands.
This paper summarizes the results presented in ApJ, 808, 110
(arXiv:1506.06246
Leptonic and Hadronic Radiative Processes in Supermassive-Black-Hole Jets
Supermassive black holes lying in the center of galaxies can launch
relativistic jets of plasma along their polar axis. The physics of black-hole
jets is a very active research topic in astrophysics, owing to the fact that
many questions remain open on the physical mechanisms of jet launching, of
particle acceleration in the jet, and on the radiative processes. In this work
I focus on the last item, and present a review of the current understanding of
radiative emission processes in supermassive-black-hole jets.Comment: Invited review in Galaxies special issue "Jet Physics of Accreting
Super Massive Black Holes
A mixed lepto-hadronic scenario for PKS 2155-304
The models developed to describe the spectral energy distribution (SED) of
blazars can be divided into leptonic or hadronic scenarios, according to the
particles responsible for the high-energy component. We have developed a new
stationary code which computes all the relevant leptonic and hadronic
processes, permitting the study of both leptonic and hadronic scenarios in a
consistent way. Interestingly, mixed lepto-hadronic scenarios (in which both
components contribute to the high energy emission) naturally arise in this
framework. We present the first application to the well known BL Lac object PKS
2155-304.Comment: 4 pages, 1 figure; to appear in the proceedings of the Gamma 2012
conferenc
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