Soft x-ray observations of pre-main sequence stars in the Chamaeleon dark cloud

Technical Report · Tue Sep 01 04:00:00 EDT 1987

OSTI ID:5776677

Feigelson, E D; Kriss, G A

Einstein IPC observations of the nearby Chamaeleon I star forming cloud show 22 well-resolved soft x-ray sources in a 1x2 deg region. Twelve are associated with H-alpha emission line pre-main sequence (PMS) stars, and four with optically selected PMS stars. Several x-ray sources have two or more PMS stars in their error circles. Optical spectra were obtained at CTIO of possible stellar counterparts of the remaining x-ray sources. They reveal 5 probable new cloud members, K7-MO stars with weak or absent emission lines. These naked x-ray selected PMS stars are similar to those found in the Taurus-Auriga cloud. The spatial distributions and H-R diagrams of the x-ray and optically selected PMS stars in the cloud are very similar. Luminosity functions indicate the Chamaeleon stars are on average approximately 5 times more x-ray luminous than Pleiad dwarfs. A significant correlation between L sub x and optical magnitude suggests this trend may continue within the PMS phase of stellar evolution. The relation of increasing x-ray luminosity with decreasing stellar ages is thus extended to stellar ages as young as 1 million years.

• Research Organization: Pennsylvania State Univ., University Park (USA). Davey Lab.
• OSTI ID: 5776677
• Report Number(s): N-88-11579; NASA-CR-181457; NAS-1.26:181457
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AGE DEPENDENCE
BALMER LINES
DATA
DISTRIBUTION
EMISSION SPECTRA
EQUIPMENT
EXPERIMENTAL DATA
IMAGE PROCESSING
INFORMATION
LUMINOSITY
MAIN SEQUENCE STARS
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
PROCESSING
RADIATION SOURCES
SPATIAL DISTRIBUTION
SPECTRA
STARS
X-RAY EQUIPMENT
X-RAY SOURCES