Observations of the core of the Pleiades with the Chandra X-ray observatory.
KRISHNAMURTHI A., REYNOLDS C.S., LINSKY J.L., MARTIN E. and GAGNE M.
Abstract (from CDS):
We present results from a 36 ks observation of the core of the Pleiades open cluster using ACIS-I on the Chandra X-Ray Observatory. We have detected 57 sources, most of which do not have previously known optical counterparts. Follow-up photometry indicates that many of the detections are likely to be active galactic nuclei, in accordance with extragalactic source counts, but some of the sources may be previously undiscovered low-mass members of the Pleiades. We discuss our data set and our findings about X-ray emission from early-type stars, as well as very late-type stars. In particular, the large X-ray fluxes, lack of variability, and hardness ratios of the four Pleiades B6 IV-F4 V stars suggest a tentative conclusion that Pleiades stars in this spectral type range are intrinsic X-ray sources rather than previously unknown binaries in which the X-ray emission is from a late-type companion. Also, the sensitivity of Chandra allowed us to detect nonflare X-ray emission from late M stars.
Galaxy: Open Clusters and Associations: Individual: Name: Pleiades - Stars: Activity - Stars: Early-Type - Stars: Low-Mass, Brown Dwarfs
VizieR on-line data:
<Available at CDS (J/AJ/121/337): table1.dat table2.dat>