A SEARCH FOR PULSATIONS FROM GEMINGA ABOVE 100 GeV WITH VERITAS

Abstract

We present the results of 71.6 hr of observations of the Geminga pulsar (PSR J0633+1746) with the VERITAS very-high-energy gamma-ray telescope array. Data taken with VERITAS between 2007 November and 2013 February were phase-folded using a Geminga pulsar timing solution derived from data recorded by the XMM-Newton and Fermi-LAT space telescopes. No significant pulsed emission above 100 GeV is observed, and we report upper limits at the 95% confidence level on the integral flux above 135 GeV (spectral analysis threshold) of 4.0x10(-13) s(-1) cm(-2) and 1.7 x 10(-13) s(-1) cm(-2) for the two principal peaks in the emission profile. These upper limits, placed in context with phase-resolved spectral energy distributions determined from 5 yr of data from the Fermi-Large Area Telescope (LAT), constrain possible hardening of the Geminga pulsar emission spectra above similar to 50 GeV.

Description
Keywords
gamma rays: stars, pulsars: general, pulsars: individual (PSR J0633+1746, Geminga), TEV GAMMA-RAYS, LARGE-AREA TELESCOPE, HIGH-ENERGY EMISSION, FERMI-LAT OBSERVATIONS, CRAB PULSAR, GALACTIC SOURCES, VELA PULSAR, PG 1553+113, X-RAY, CATALOG, Astronomy & Astrophysics
Citation
Aliu, E., et al. (2015): A Search for Pulsations from Geminga above 100 GeV with VERITAS. The Astrophysical Journal, 800(1). DOI: http://dx.doi.org/10.1088/0004-637X/800/1/61