132 citations · 827 across the 18 of their papers we have counts for
18 papers
The variability patterns of the TeV blazar PG 1553+113 from a decade of MAGIC and multi-band observations
MAGIC Collaboration, H. Abe, S. Abe +264
PG 1553+113 is one of the few blazars with a convincing quasi-periodic emission in the gamma-ray band. The source is also a very high-energy (VHE; >100 GeV) gamma-ray emitter. To b…
The circum-galactic medium of quasars: transverse and line-of-sight absorptions
Angela Sandrinelli, Renato Falomo, Aldo Treves +2
Quasar projected pairs (QPPs) can be used for investigating the circumgalactic medium of quasars through the study of intervening absorption lines in the spectrum of the background…
Looking at Blazar Light Curve Periodicities with Gaussian Processes
Stefano Covino, Marco Landoni, Angela Sandrinelli +1
Temporal analysis of blazar flux is a powerful tool to draw inferences about the emission processes and physics of these sources. In the most general case, the available light curv…
Do BL Lac Objects and FR I radiogalaxies inhabit the same galaxy environment?
A. Sandrinelli, R. Falomo, A. Treves
We investigate the environments of galaxies around BL Lac objects and FR I radiogalaxies, the alleged parent populations of misaligned sources. We compare the environment of a samp…
Gamma-ray quasi-periodicities of blazars. A cautious approach
Stefano Covino, Angela Sandrinelli, Aldo Treves
The availability of about a decade of uninterrupted sky monitoring by the Fermi satellite has made possible to study long-term quasi-periodicities for high-energy sources. It is th…
Pulsar Timing Constraints on the Fermi Massive Black-Hole Binary Blazar Population
A. Miguel Holgado, Alberto Sesana, Angela Sandrinelli +4
Blazars are a sub-population of quasars whose jets are nearly aligned with the line-of-sight, which tend to exhibit multi-wavelength variability on a variety of timescales. Quasi-p…
Detection of persistent VHE gamma-ray emission from PKS 1510-089 by the MAGIC telescopes during low states between 2012 and 2017
MAGIC Collaboration, V. A. Acciari, S. Ansoldi +165
PKS 1510-089 is a flat spectrum radio quasar strongly variable in the optical and GeV range. We search for low-state VHE gamma-ray emission from PKS 1510-089. We aim to characteriz…
Quasi-periodicities of BL Lac Objects
Angela Sandrinelli, Stefano Covino, Aldo Treves +4
We review the reports of possible year-long quasi-periodicities of BL Lac objects in the -ray and optical bands, and present a homogeneous time analysis of the light curves of P…
Overdensity of galaxies in the environment of quasar pairs
Angela Sandrinelli, Renato Falomo, Aldo Treves +2
We report on a study of the galaxy environments of low redshift physical quasars pairs. We selected 20 pairs having projected separation 0.5 Mpc and difference of systemic velo…
Quasi-Periodicities at Year Time Scales in Blazars
Stefano Covino, Angela Sandrinelli, Aldo Treves
We examine the 2008-2016 gamma-ray and optical light curves of a number of bright Fermi blazars. In a fraction of them, the periodograms show possible evidence of quasi-periodiciti…
Gamma-ray and Optical Oscillations of 0716+714, MRK 421, and BL Lac
A. Sandrinelli, S. Covino, A. Treves +12
We examine the 2008-2016 -ray and optical light curves of three bright BL Lac objects, 0716+714, MRK 421, BL Lac, which exhibit large structured variability. We searched for per…
Gamma-ray and optical oscillations in the blazar PKS 0537-441
Angela Sandrinelli, Stefano Covino, Aldo Treves
We have considered the \textit{Fermi} -ray light curve of the blazar PKS 0537-441 during a high state extending from 2008/08/10 to 2011/08/27. The periodogram exhibits a peak at…
Quasi-periodicities at year-like timescales in Blazars
Angela Sandrinelli, Stefano Covino, Massimo Dotti +1
We searched for quasi-periodicities on year-like timescales in the light curves of 6 blazars in the optical - near infrared bands and we made a comparison with the high energy emis…
Short Timescale Photometric and Polarimetric Behavior of two BL Lacertae Type Objects
S. Covino, M. C. Baglio, L. Foschini +20
Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general pict…
Quasi-periodicities of PKS 2155-304
Angela Sandrinelli, Stefano Covino, Aldo Treves
We have searched for periodicities in our VRIJHK photometry of PKS 2155-304, which covers the years 2005-2012. A peak of the Fourier spectrum with high significance is found at T$\…
The environment of low redshift quasar pairs
Angela Sandrinelli, Renato Falomo, Aldo Treves +2
We investigate the properties of the galaxy environment of a sample of 14 low redshift (z 0.85) quasar physical pairs extracted from SDSS DR10 archives. The pairs have a system…
MAGIC gamma-ray and multifrequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012
MAGIC Collaboration, J. Aleksić, S. Ansoldi +218
Among more than fifty blazars detected in very high energy (VHE, E>100GeV) gamma-rays, only three belong to the subclass of Flat Spectrum Radio Quasars (FSRQs). MAGIC observed FSRQ…
Long and short term variability of seven blazars in six near-infrared/optical bands
Angela Sandrinelli, Stefano Covino, Aldo Treves
Context. We present the light curves of six BL Lac objects, PKS 0537-441, PKS 0735+17, OJ 287, PKS 2005-489, PKS 2155-304, W Comae, and of the flat spectrum radio quasar PKS 1510-0…