Einstein X-ray survey of the Pleiades - the dependence of X-ray emission on stellar age

Journal Article · Wed May 01 04:00:00 EDT 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163143· OSTI ID:6060620

Micela, G; Sciortino, S; Serio, S; Vaiana, G S; Bookbinder, J; Golub, L; Harnden, JR, F R; Rosner, R

The data obtained with two pointed observations of 1 deg by 1 deg fields of the Pleiades region have been analyzed, and the results are presented. The maximum-likelihood X-ray luminosity functions for the Pleiades G and K stars in the cluster are derived, and it is shown that, for the G stars, the Pleiades X-ray luminosity function is significantly brighter than the corresponding function for Hyades G dwarf stars. This finding indicates a dependence of X-ray luminosity on stellar age, which is confirmed by comparison of the same data with median X-ray luminosities of pre-main sequence and local disk population dwarf G stars. It is suggested that the significantly larger number of bright X-ray sources associated with G stars than with K stars, the lack of detection of M stars, and the relatively rapid rotation of the Pleiades K stars can be explained in terms of the onset of internal differential rotation near the convective envelope-radidative core interface after the spin-up phase during evolution to the main sequence. 48 references.

• Research Organization: Osservatorio Astronomico, Palermo, Italy; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA
• OSTI ID: 6060620
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 292; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CATALOGS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DOCUMENT TYPES
DWARF STARS
LUMINOSITY
MOTION
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
ROTATION
STAR CLUSTERS
STARS