SIMBAD references

2010ApJ...708..364B - Astrophys. J., 708, 364-374 (2010/January-1)

The first detection of [O IV] from an ultraluminous X-ray source with Spitzer. II. Evidence for high luminosity in Holmberg II ULX.


Abstract (from CDS):

This is the second of two papers examining Spitzer Infrared Spectrograph observations of the ultraluminous X-ray source (ULX) in Holmberg II. Here, we perform detailed photoionization modeling of the infrared lines. Our analysis suggests that the luminosity and morphology of the [O IV] 25.89 µm emission line is consistent with photoionization by the soft X-ray and far ultraviolet (FUV) radiation from the accretion disk of the binary system and inconsistent with narrow beaming. We show that the emission nebula is matter-bounded both in the line-of-sight direction and to the east, and probably radiation-bounded to the west. A bolometric luminosity in excess of 1040 erg/s would be needed to produce the measured [O IV] flux. We use modeling and previously published studies to conclude that shocks likely contribute very little, if at all, to the high-ionization line fluxes observed in the Holmberg II ULX. Additionally, we find that the spectral type of the companion star has a surprisingly strong effect on the predicted strength of the [O IV] emission. This finding could explain the origin of [O IV] in some starburst systems containing black hole binaries.

Abstract Copyright:

Journal keyword(s): black hole physics - galaxies: individual: Holmberg II - infrared: ISM - X-rays: binaries

Simbad objects: 9

goto Full paper

goto View the reference in ADS

To bookmark this query, right click on this link: simbad:2010ApJ...708..364B and select 'bookmark this link' or equivalent in the popup menu


© Université de Strasbourg/CNRS

    • Contact