NuSTAR Observations of the Norma Arm Region
Abstract
One of the Galactic regions being surveyed by NuSTAR covers a 2 degree x 0.8 degree region of the Norma Arm that was observed with Chandra in 2011. This region was selected because its recent star formation and large number of OB associations make it a good place to search for and study X-ray sources associated with massive stars, such as high-mass X-ray binaries (HMXBs) and colliding wind binaries (CWBs). For the vast majority of sources in this region, the Chandra data are insufficient for constraining their individual spectral parameters and identifying their physical nature, but combining NuSTAR and Chandra data provides strong constraints on their X-ray properties. Roughly a third of the area surveyed by Chandra has been observed with NuSTAR to date, and we present preliminary results identifying the hard X-ray sources observed by both telescopes. We have obtained near-infrared spectra of the counterparts of some of these X-ray sources, which also facilitate their identifications. Although our analysis is ongoing, a significant fraction of sources appear to be intermediate polars, some are likely CWBs and HMXBs, and one may be a black hole binary.
- Publication:
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AAS/High Energy Astrophysics Division #14
- Pub Date:
- August 2014
- Bibcode:
- 2014HEAD...1411701F