|
|
Articles
ROSAT Detection of an X-ray Shadow in the 1/4-keV Diffuse Background in the Draco Nebula
1 Max-Planck-Institut für Extraterrestrische Physik, D-8046 Garching bei München, Federal Republic of Germany, and Department of Physics, University of Wisconsin, Madison, WI 53706
The detection by the Roentgen satellite (ROSAT) x-ray telescope of a shadow in the 1/4—kiloelectron volt (C band, 0.1 to 0.284 kiloelectron volt) cosmic diffuse background is reported. The location and morphology of the local minimum in x-rays are in clear agreement with a discrete H I cloud. The shadow is very deep with a minimum level at 50 percent of the surrounding emission; therefore, a minimum of 50 percent of the observed off-cloud flux must originate on the far side of the cloud. The analysis of H I velocity components links the cloud with the Draco nebula (distance Accepted on May 2, 1991
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
|
600 parsecs); it then follows that there is significant 1/4—kiloelectron volt x-ray emission at a large distance (>400 parsecs) from the galactic plane along this line of sight. The extent of the distant emission region is uncertain, and, if it indicates the existence of a hot galactic corona, it must be patchy in nature.Science. ISSN 0036-8075 (print), 1095-9203 (online)
News | Science Journals | Careers | Blogs and Communities | Multimedia | Collections | Help | Site Map | RSS
Subscribe | Feedback | Privacy / Legal | About Us | Advertise With Us | Contact Us
© 1991 American Association for the Advancement of Science. All Rights Reserved.
AAAS is a partner of HINARI, AGORA, PatientInform, CrossRef, and COUNTER.
You have reached the bottom of the page. Back to top