Chandra X-ray Observatory - HomeAbout The ChandraEducational MaterialsField GuidePhoto AlbumPress RoomResources
Chandra X-ray Observatory - HomeChandra Resources - You are here
ObservatoryMultimediaImages and IllustrationsAnimations and VideoChandra Special FeaturesChandra PodcastsPresentationsVirtual PostcardsHandouts and ActivitiesDesktop ImagesScreen SaversAudioQ&AGlossaryAcronym GuideFurther Reading
Web Site ToolsVisit the Chandra ChroniclesEmail NewsletterSite MapNew & NoteworthyImage Use PolicyQuestions & AnswersGlossaryDownload Guide

Q&A: Supernova Remnants and Neutron Stars



Q:

I saw the photo of the remnants of Cassiopeia A which exploded some 300 years ago (from our frame of reference). How can the gases still be at 50 million degrees? Wouldn't the density of the gas have decreased to a point that the temperature dropped significantly?

A:

It's the low density of the gas in supernova remnants that results in its slow cooling. Cooling processes like collisions act faster with high density gas, and slower with low density gas.

Back | Index | Next
separator line
CXC Home | Search | Help | Site Map | Image Use Policy | Privacy & Accessibility | Downloads & Plugins
Latest Images | New & Noteworthy | Multimedia | Flash Ecards | Glossary | Q&A | Guestbook


RSS Feed RSS Feed | Podcast Podcast | Blog Blog

[News by email: Chandra Digest]
[Contact us: cxcpub@cfa.harvard.edu]
NASA's Home Page Smithsonian's Home Page CXC Home Page Image Map for NASA's, Smithsonian and Chandra's Home Pages
Harvard-Smithsonian Center for Astrophysics
60 Garden Street, Cambridge, MA 02138 USA
Phone: 617.496.7941 Fax: 617.495.7356


Text Size:
normal font large font larger font
Chandra X-ray Center, Operated for NASA by the Smithsonian Astrophysical Observatory
This site was developed with funding from NASA under Contract NAS8-03060.
Revised: August 31, 2005