Chandra Observations Of Ulirg Iras 19254-7245 (the Superantennae)
Abstract
We present a Chandra observation of IRAS 19254-7245, a nearby ULIRG also known as the Superantennae. The high spatial resolution of Chandra allows us to disentangle for the first time the diffuse starburst emission from the embedded Compton-thick AGN. The 2-10 keV spectrum of the AGN emission is fit well by a flat power-law (Γ=1.3) and a He-like Fe Kα line, consistent with previous XMM-Newton and Suzaku observations. We fit the spectrum of the extended emission within 25" radius from the AGN and excluding the AGN and other bright point sources. The diffuse emission requires two components, which when fit with thermal models give temperatures of 0.7 keV and 6.3 keV. An ionized Fe Kα line is marginally detected in the diffuse emission with an apparently high EW, suggesting either high abundances or non-thermal contributions to the line. An ultra-luminous X-ray source is detected 9\arcsec south of the southern nucleus. The 0.3-10keV luminosity of this ULX is 9e+40 erg/s if this source is associated with the Superantennae. We acknowledge support from Chandra grant GO9-0091X.
- Publication:
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AAS/High Energy Astrophysics Division #12
- Pub Date:
- September 2011
- Bibcode:
- 2011HEAD...12.3517J