Spectacular Trailing Streamers near LMC X-1: The First Evidence of a Jet?

Abstract

We report VIMOS integral field spectroscopy of the N159F nebula surrounding LMC X-1. Our observations reveal a rich, extended system of emission line filaments lining the boundary of a large conical cavity identified in Spitzer mid-IR imaging. We find that X-ray photoionization cannot be solely responsible for the observed ionization structure of N159F. We propose that the extended filamentary emission is produced primarily by ionization from a shock driven by a presently unobserved jet from LMC X-1. We infer a shock velocity of v_s ~ 90 km/s and conclude that the jet responsible for the bow shock is presently undetected because it has switched off, rather than because it has a low surface brightness. This interpretation is consistent with the present soft X-ray spectral state of LMC X-1 and suggests the jet is intermittent.

Accepted for publication in The Astrophysical Journal Letters. Hi-res figure available at http://www.physics.usyd.edu.au/~kuncic/LMCX1/Cooke_etal_fig1.eps.gz