Program of ground-based astronomy to complement Einstein observations. Annual scientific report, 1 October 1983-30 September 1984

Technical Report · Fri Nov 30 04:00:00 EST 1984

OSTI ID:5660373

Helfand, D J

The objective of the funded research is the formulation and execution of ground-based astronomical observations and interpretive studies complementary to the x-ray data accumulated with the Einstein satellite, to be used in addressing a number of questions of current astrophysical interest. During the past year, the program focussed on two main topics: the processes leading to high-energy emission in the winds and coronae of late-type stars, and the structure and evolution of supernova remnants and the neutron stars they may contain. The stellar work encompasses the development of a complete, x-ray flux-limited sample of stars which, when combined with a complete, magnitude-limited optical sample will provide the best available description of the distribution of coronal activity in stars of spectral types F through M. A principal corollary of this work is the determination of the contribution of coronally active M dwarfs to the diffuse x-ray background. Star-cluster studies are combined with the survey work toward the goal of specifying the critical factors governing the production and evolution of magnetically dominated coronae in late-type stars. The supernova remnant work concentrates on the twin problems of the evidence for and frequency of neutron-star formation in supernova explosions and the time development of the luminosity and size of the expanding supernova shock wave.

• Research Organization: Columbia Univ., New York (USA). Columbia Astrophysics Lab.
• OSTI ID: 5660373
• Report Number(s): AD-A-151111/2/XAB; CAL-1553
• 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
ATMOSPHERES
COSMIC RADIO SOURCES
EMISSION SPECTRA
ERUPTIVE VARIABLE STARS
GALAXIES
LUMINESCENCE
NEBULAE
NEUTRON STARS
NUCLEOSYNTHESIS
SHOCK WAVES
SPECTRA
STARS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR WINDS
SUPERNOVA REMNANTS
SUPERNOVAE
SYNTHESIS
VARIABLE STARS