New X-ray Detections of WNL Stars

Details New X-ray Detections of WNL Stars New X-ray Detections of WNL Stars

2012-03-22

arxiv.org/abs/1203.5098v1

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

20 pages, 5 figures

Scientific paper

Previous studies have demonstrated that putatively single nitrogen-type Wolf-Rayet stars (WN stars) without known companions are X-ray sources. However, almost all WN star X-ray detections so far have been of earlier WN2 - WN6 spectral subtypes. Later WN7 - WN9 subtypes (also known as WNL stars) have proved more difficult to detect, an important exception being WR 79a (WN9ha). We present here new X-ray detections of the WNL stars WR 16 (WN8h) and WR 78 (WN7h). These new results, when combined with previous detections, demonstrate that X-ray emission is present in WN stars across the full range of spectral types, including later WNL stars. The two WN8 stars observed to date (WR 16 and WR 40) show unusually low X-ray luminosities (Lx) compared to other WN stars, and it is noteworthy that they also have the lowest terminal wind speeds (v_infty). Existing X-ray detections of about a dozen WN stars reveal a trend of increasing Lx with wind luminosity Lwind = (1/2) M_dot v_infty^2, suggesting that wind kinetic energy may play a key role in establishing X-ray luminosity levels in WN stars.

Affiliated with

Also associated with

No associations

Rating

New X-ray Detections of WNL Stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with New X-ray Detections of WNL Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and New X-ray Detections of WNL Stars will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-382520