Dr
Daniela Huppenkothen
(New York University)
12/8/16, 9:00 AM
HAP Workshop
Oral
Virtually all astronomical sources are variable on some time scale, making studies of variability across different wavelengths a major tool in pinning down the underlying physical processes, for example accretion onto compact objects and cataclysmic explosions like gamma-ray bursts. The new telescopes currently starting operations or coming online in the coming years, including the Square...
Mr
Ioannis Liodakis
(University of Crete, FORTH)
12/8/16, 9:30 AM
HAP Workshop
Oral
Blazars are known to show periods of quiescence followed by extreme outbursts seen throughout the electromagnetic spectrum. We present a novel maximum likelihood approach to capturing this bimodal behavior by examining blazar radio variability in the flux-density domain. We separate quiescent and flaring components of a source's light curve by modeling its flux-density distribution as a series...
Dr
Guillaume Belanger
(European Space Agency)
12/8/16, 9:50 AM
HAP Workshop
Oral
Time domain astronomy and astrophysics are concerned with studying the temporal characteristics of the light from distant astrophysical sources that our instruments detect. Consequently, time domain studies are aimed at the detection and characterisation of variability: periodic variability, aperiodic or stochastic variability, and transient events. In this presentation, I propose to introduce...
Dr
Arti Goyal
(Astronomical observatory of the Jagiellonian University)
12/8/16, 10:10 AM
HAP Workshop
Oral
The typical shape of blazar lightcurves' power spectra is a power-law, $P(f) = A f^{-\beta}$, where A is the normalization and $\beta$ is the slope, indicating that the variability is generated by the underlying $\it stochastic$ processes which is of colored noise type (i.e., $\beta \simeq 1-3$). Here we present the results of power spectral analysis of 5 blazars utilizing the $\it Fermi$-LAT...
Walter Max-Moerbeck
(Max-Planck-Institut für Radioastronomie)
12/8/16, 11:45 AM
HAP Workshop
Oral
I will discuss our efforts to determine the location of the gamma-ray emission site in blazars with the ongoing OVRO 40 meter telescope blazar monitoring program. This program started in 2008 and is currently monitoring about 1800 blazars at 15 GHz with twice a week cadence for a sample including most of the bright blazars north of declination -20 degrees. A summary of previous findings and...
Dr
Nachiketa Chakraborty
(Max Planck Institute for Nuclear Physics)
12/8/16, 12:05 PM
HAP Workshop
Oral
Despite intensive research over a few decades facilitated by highly sensitive multiwavelength (MWL) telescopes, fundamental characteristics of active galactic nuclei (AGNs) are still open. With respect to physics of individual AGNs, the location and mechanisms of particle acceleration, their connection to flaring, relative importance of hadronic and leptonic processes in specific sources and...
Dr
Tim Ruhe
(TU Dortmund)
12/8/16, 12:25 PM
HAP Workshop
Oral
Obtaining energy spectra of incident particles such as neutrinos or gamma-rays is a common challenge in neutrino- and Air-Cherenkov astronomy, as the particle's energy cannot be observed directly but has to be inferred from other observables e.g. energy losses of secondary particles utilized for detection. The task is further made difficult by the fact that the production of secondaries, e.g....
