2015ApJ...801...49B -
Astrophys. J., 801, 49 (2015/March-1)
A first look at the X-ray population of the young massive cluster VVV CL077.
BODAGHEE A., TOMSICK J.A., FORNASINI F., RAHOUI F. and BAUER F.E.
Abstract (from CDS):
Multi-wavelength analysis of the young massive cluster VVV CL077 is presented for the first time. Our Chandra survey of this region enabled the detection of three X-ray emitting stellar members of the cluster, as well as a possible diffuse X-ray component that extends a few arcseconds from the cluster core with an intrinsic flux of (9±3)x10–14 erg/cm2/s in the 0.5-10 keV band. Infrared spectra we obtained for two of these X-ray point sources show absorption lines typical of the atmospheres of massive O stars. The X-ray spectrum from the visible extent of VVV CL077 i.e., a 15'' radius around the cluster, can be modeled with an absorbed power law with NH= (6–3+4) x 1022/cm2 and Γ = 2±1. In addition, the X-ray core of VVV CL077 coincides with diffuse emission seen in the infrared band and with a local maximum in the radio continuum map. A possible association with a neighboring H II region would place VVV CL077 at a distance of around 11 kpc, on the far side of the Norma Arm. At this distance, the cluster is 0.8 pc wide with a mass density of (1-4)x103 M☉/pc3.
Abstract Copyright:
∼
Journal keyword(s):
infrared: stars - open clusters and associations: individual: VVV CL077 - stars: early-type - X-rays: stars
Simbad objects:
17
View the references in ADS