Publications (10)
Active Galactic Nuclei: The TeV Challenge
R. Blandford, W. East, K. Nalewajko +2
Jets associated with Active Galactic Nuclei (AGN) have been observed for almost a century, initially at optical and radio wavelengths. They are now widely accepted as "exhausts" pr…
Extreme Plasma Astrophysics
D. Uzdensky, M. Begelman, A. Beloborodov +22
This is a science white paper submitted to the Astro-2020 and Plasma-2020 Decadal Surveys. The paper describes the present status and emerging opportunities in Extreme Plasma Astro…
Insights into Supermassive Black Hole Mergers from the Gravitational Wave Background
C. M. F. Mingarelli, L. Blecha, T. BogdanoviÄ +9
At the Kavli Institute for Theoretical Physics, participants of the rapid response workshop on the gravitational wave background explored discrepancies between experimental results…
Search for Periodic Variability in -ray Blazars Using \textit{Fermi}-LAT
P. Peñil, M. Ajello, S. Buson +5
Blazars are known to exhibit variability across a broad range of timescales. This behavior can include periodicity in their -ray emission, whose clear detection remains an ongo…
Two years of non-thermal emission from the binary neutron star merger GW170817: rapid fading of the jet afterglow and first constraints on the kilonova fastest ejecta
A. Hajela, R. Margutti, K. D. Alexander +27
We present Chandra and VLA observations of GW170817 at ~521-743 days post merger, and a homogeneous analysis of the entire Chandra data set. We find that the late-time non-thermal…
A Decline in the X-ray through Radio Emission from GW170817 Continues to Support an Off-Axis Structured Jet
K. D. Alexander, R. Margutti, P. K. Blanchard +17
We present new observations of the binary neutron star merger GW170817 at days post-merger, at radio (Karl G. Jansky Very Large Array; VLA), X-ray (Chandra X-r…
The Binary Neutron Star event LIGO/VIRGO GW170817 a hundred and sixty days after merger: synchrotron emission across the electromagnetic spectrum
Raffaella Margutti, K. D. Alexander, X. Xie +17
We report deep Chandra, HST and VLA observations of the binary neutron star event GW170817 at d after merger. These observations show that GW170817 has been steadily bright…
Multiwavelength Analysis of Fermi-LAT Blazars with High-Significance Periodicity: Detection of a Long-Term Rising Emission in PG 1553+113
P. Peñil, J. R. Westernacher-Schneider, M. Ajello +6
Blazars display variable emission across the entire electromagnetic spectrum, with timescales that can range from a few minutes to several years. Our recent work has shown that a s…
The Optical Afterglow of GW170817: An Off-axis Structured Jet and Deep Constraints on a Globular Cluster Origin
Wen-fai Fong, P. K. Blanchard, K. D. Alexander +25
We present a revised and complete optical afterglow light curve of the binary neutron star merger GW170817, enabled by deep Hubble Space Telescope (HST) F606W observations at $\app…
Evidence for X-ray Emission in Excess to the Jet Afterglow Decay 3.5 yrs After the Binary Neutron Star Merger GW 170817: A New Emission Component
A. Hajela, R. Margutti, J. S. Bright +34
For the first years after the binary neutron star merger event GW 170817 the radio and X-ray radiation has been dominated by emission from a structured relativistic off-axi…