NuSTAR, Chandra, and VLBA Monitoring of the X-ray Binary Population in NGC 253
Abstract
We present results from simultaneous NuSTAR, Chandra, and VLBA monitoring of the X-ray binary population in local star-forming galaxy NGC 253. Given the relatively high specific star-formation rate of NGC 253, we expect the X-ray binary population in NGC 253 to be primarily high-mass X-ray binaries (HMXBs) in contrast to the low-mass X-ray binary dominant population in the Milky Way. Our monitoring consisted of three observational periods, each including 165 ks with NuSTAR, 20 ks with Chandra, and 28 ks with the VLBA. The monitoring was designed to (1) sensitively isolate the locations of X-ray binaries, (2) determine the nature of the accreting compact objects via their 0.5-30 keV spectral properties, and (3) identify interesting flaring X-ray/radio sources as they make spectral state transitions due to variability in their accretion. Thanks to the advanced imaging resolution and throughput unique to NuSTAR, we now have the first ever resolved X-ray image of NGC 253 at energies out to ~30 keV, which is critical for determining the nature of the accreting compact object. In this poster, we highlight initial results from our monitoring observations and focus on the unique constraints related to the handful of sources detected by NuSTAR at 7-30 keV.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22124422L