The stringent upper limit on jet power in the persistent soft state source 4U~1957+11
Abstract
We present extremely deep upper limits on the radio emission from 4U~1957+11, an X-ray binary that is generally believed to be a persistently accreting black hole that is almost always in the soft state. We discuss a more comprehensive search for Type I bursts than in past work, revealing a stringent upper limit on the burst rate, bolstering the case for a black hole accretor. The lack of detection of this source at the 1.07 Jy/beam noise level indicates jet suppression that is stronger than expected even in the most extreme thin disk models for radio jet production -- the radio power here is 1500--3700 times lower than the extrapolation of the hard state radio/X-ray correlation, with the uncertainties depending primarily on the poorly constrained source distance. We also discuss the location and velocity of the source and show that it must have either formed in the halo or with a strong asymmetric natal kick.
Keywords
Cite
@article{arxiv.2007.00834,
title = {The stringent upper limit on jet power in the persistent soft state source 4U~1957+11},
author = {Thomas J. Maccarone and Arlo Osler and James C. A. Miller-Jones and P. Atri and David M. Russell and David L. Meier and Ian M. McHardy and Penelope A. Longa-Peña},
journal= {arXiv preprint arXiv:2007.00834},
year = {2020}
}
Comments
6 page, 2 figures, accepted to Monthly Notices of the Royal Astronomical Society Letters