Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 25 November 1966:
Vol. 154. no. 3752, pp. 1000 - 1002
DOI: 10.1126/science.154.3752.1000
Prev | Table of Contents | Next

Articles

Energy Spectra of a Number of Celestial X-Ray Sources in the Energy Range from 2 to 60 Kiloelectron Volts

K. G. McCracken 1

1 Southwest Center for Advanced Studies, Dallas, Texas

The emission of 20 to 60 kev x-rays by an astronomical object in the constellation of Cygnus has been observed with a balloon-borne x-ray telescope flown from Hyderabad, India. The balloon data, used in conjunction with data pertaining to the flux in the wavelength range from 2 to 10 Å can be fitted by a power law in photon energy varying as (hv)-1.7. The Cygnus object is the brightest object in the sky in the hard x-ray wavelength range and has the hardest spectrum of all observed objects that emit x-rays. The astronomical object should be capable of accelerating protons up to energies of the order of 1018 electron volts. Upper limits to the hard x-ray fluxes from Sco XR-1, Cyg XR-2, Oph XR-1, and Ser XR-1 are established; it is shown that the Sco XR-1 spectrum is very soft.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Relativistic Astrophysics.
S. P. Maran and A. G. W. Cameron (1967)
Science 157, 1517-1524
   PDF »
Distribution and Variability of Cosmic X-Ray Sources.
H. Friedman, E. T. Byram, and T. A. Chubb (1967)
Science 156, 374-378
   Abstract »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)