Radio emission from the X-ray pulsar Her X-1: a jet launched by a strong magnetic field neutron star? [HEAP]

http://arxiv.org/abs/1711.01971


Her X-1 is an accreting neutron star in an intermediate-mass X-ray binary. Like low-mass X-ray binaries (LMXBs), it accretes via Roche-lobe overflow, but similar to many high-mass X-ray binaries containing a neutron star, Her X-1 has a strong magnetic field and slow spin. Here, we present the discovery of radio emission from Her X-1 with the Very Large Array. During the radio observation, the central X-ray source was partially obscured by a warped disk. We measure a radio flux density of $38.7 \pm 4.8$ $\mu$Jy at $9$ GHz but can not constrain the spectral shape. We discuss possible origins of the radio emission, and conclude that coherent emission, a stellar wind, shocks and a propeller outflow are all unlikely explanations. A jet, as seen in LMXBs, is consistent with the observed radio properties. We consider the implications of the presence of a jet in Her X-1 on jet formation mechanisms and on the launcing of jets by neutron stars with strong magnetic fields.

Read this paper on arXiv…

J. Eijnden, N. Degenaar, T. Russell, et. al.
Tue, 7 Nov 17
111/118

Comments: 5 pages, 2 figures; accepted for publication in MNRAS Letters