Observations of the unidentified gamma-ray source TeV J2032+4130 by veritas

Abstract

TeV J2032+4130 was the first unidentified source discovered at very high energies (VHEs; E > 100 GeV), with no obvious counterpart in any other wavelength. It is also the first extended source to be observed in VHE gamma rays. Following its discovery, intensive observational campaigns have been carried out in all wavelengths in order to understand the nature of the object, which have met with limited success. We report here on a deep observation of TeV J2032+4130 based on 48.2 hr of data taken from 2009 to 2012 by the Very Energetic Radiation Imaging Telescope Array System experiment. The source is detected at 8.7 standard deviations (σ) and is found to be extended and asymmetric with a width of 9.′5 ± 1.′2 along the major axis and 4.′0 ± 0.′5 along the minor axis. The spectrum is well described by a differential power law with an index of 2.10 ± 0.14 stat ± 0.21sys and a normalization of (9.5 ± 1.6stat ± 2.2sys) × 10-13 TeV-1 cm-2 s-1 at 1 TeV. We interpret these results in the context of multiwavelength scenarios which particularly favor the pulsar wind nebula interpretation. © 2014. The American Astronomical Society. All rights reserved..