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Einstein X-ray survey of the Pleiades - The dependence of X-ray emission on stellar ageThe 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.
Document ID
19850053267
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Micela, G. (Osservatorio Astronomico Palermo, Italy)
Sciortino, S. (Osservatorio Astronomico Palermo, Italy)
Serio, S. (Osservatorio Astronomico Palermo, Italy)
Vaiana, G. S. (Osservatorio Astronomico, Palermo, Italy; Harvard-Smithsonian Center for Astrophysics, Cambridge MA, United States)
Bookbinder, J. (Osservatorio Astronomico Palermo, Italy)
Golub, L. (Osservatorio Astronomico Palermo, Italy)
Harnden, F. R., Jr. (Osservatorio Astronomico Palermo, Italy)
Rosner, R. (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Date Acquired
August 12, 2013
Publication Date
May 1, 1985
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 292
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAG8-445
CONTRACT_GRANT: NAS8-30751
CONTRACT_GRANT: NAGW-112
Distribution Limits
Public
Copyright
Other