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arXiv · 1808.04132

The Enigmatic compact radio source coincident with the energetic X-ray pulsar PSR J1813$-$1749 and HESS J1813$-$178

Sergio A. Dzib·Luis F. Rodríguez·Ramesh Karupussamy·Laurent Loinard·Sac-Nicté X. Medina
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Abstract

New VLA detections of the variable radio continuum source VLA J181335.1$-$174957, associated with the energetic X-ray pulsar PSR~J1813$-$1749 and the TeV source HESS J1813-178, are presented. The radio source has a right circular polarization of $\sim50\%$, and a negative spectral index of $-1.3\pm0.1$, which show that it is non-thermal. The radio pulses of the pulsar are not detected from additional Effelsberg observations at 1.4~GHz made within one week of a VLA detection. This result would appear to support the idea that the continuum radio emission detected with the VLA does not trace the time-averaged emission pulses, as had previously been suggested. We discuss other possible origins for the radio source, such as a pulsar wind, magnetospheric emission, and a low-mass star companion. However, observations made at higher frequencies by Camilo et al. (in preparation) show that the VLA source is in fact the time-averaged pulsed emission and that the detection of the pulses had not been achieved because this is the most scattered pulsar known.

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Sergio A. Dzib, Luis F. Rodríguez, Ramesh Karupussamy, Laurent Loinard, Sac-Nicté X. Medina. 2018-08-13. The Enigmatic compact radio source coincident with the energetic X-ray pulsar PSR J1813$-$1749 and HESS J1813$-$178. https://doi.org/10.3847/1538-4357%2Faada07

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