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Full-Text Articles in Other Astrophysics and Astronomy

A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, P. T. Reynolds, Et Al Feb 2016

A Search For Brief Optical Flashes Associated With The Seti Target Kic 8462852, P. T. Reynolds, Et Al

Physical Sciences Publications

The F-type star KIC 8462852 has recently been identified as an exceptional target for search for extraterrestrial intelligence (SETI) observations. We describe an analysis methodology for optical SETI, which we have used to analyze nine hours of serendipitous archival observations of KIC 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately , is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.


Exceptionally Bright Tev Flares From The Binary Ls I+61 Degrees 303, P. T. Reynolds, Et Al Jan 2016

Exceptionally Bright Tev Flares From The Binary Ls I+61 Degrees 303, P. T. Reynolds, Et Al

Physical Sciences Publications

The TeV binary system LS I +61° 303 is known for its regular, non-thermal emission pattern that traces the orbital period of the compact object in its 26.5 day orbit around its B0 Ve star companion. The system typically presents elevated TeV emission around apastron passage with flux levels between 5% and 15% of the steady flux from the Crab Nebula (>300 GeV). In this article, VERITAS observations of LS I +61° 303 taken in late 2014 are presented, during which bright TeV flares around apastron at flux levels peaking above 30% of the Crab Nebula flux were detected. …


Shock Study In Fully Relativistic Isothermal Flows. Ii, Ruixin Yang, Menas Kafatos Jan 1995

Shock Study In Fully Relativistic Isothermal Flows. Ii, Ruixin Yang, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

The isothermal shocks and their stabilities in fully relativistic accretion wedge flows onto black holes are studied. The jump condition across the shock is modified by the relativistic effects when the sound speed is comparable to the speed of light. With a new kind of instability analysis, it is found that only one of the two possible shocks is stable. The results are applied to the QPO behavior in galactic black hole candidates such as Cygnus X-1.