IC 2497
IC 2497 is a spiral galaxy[3] close to the intergalactic cloud Hanny's Voorwerp.[1]
IC 2497 is a former quasar, whose light lit up Hanny's Voorwerp, which is now a light echo of that extinct quasar.[4] It is about 45,000–70,000 light-years (14,000–21,000 pc) away from Hanny's Voorwerp.[5] The quasar shut down sometime in the last 70,000 years.[6] This revises current theories of quasar operation, as the quasar is quiescient, shutting down much faster than was thought possible,[7] and is much cooler than predicted.[5] The galaxy is currently 100 to 10,000 times dimmer than it was when its quasar burned into Hanny's Voorwerp.[8] It is currently the nearest known quasar, being 730 million light years away, and the one with the best view of its host galaxy.[8] The nearest active quasar is 3C 273, 1.7 billion light years further away.[9]
References
- ^ a b c d e f SIMBAD, "IC 2497" (accessed 2010-11-11)
- ^ Sky Factory, "IC 2497", Davide De Martin, 2007 (accessed 2010-11-11)
- ^ BBC News, "Teacher finds new cosmic object", Paul Rincon, 5 August 2008 (accessed 2010-11-11)
- ^ ScienceDaily, "Cosmic Curiosity Reveals Ghostly Glow of Dead Quasar", 6 November 2010 (accessed 2010-11-10)
- ^ a b Softpedia, "Shut Down Quasar Found Close By", Tudor Vieru, 3 November 2010 (accessed 2010-10-11)
- ^ Universe Today, "What Hanny’s Voorwerp Reveals About Quasar Deaths", Jon Voisey, 3 November 2010 (accessed 2010-11-11)
- ^ ECN Magazine, "Cosmic Curiosity Reveals Ghostly Glow of Dead Quasar", Yale University, 3 November 2010 (accessed 2010-11-11)
- ^ a b Wired, "Rare Dead Quasar Found in Nearby Galaxy", Lisa Grossman, 2 November 2010 (accessed 2010-11-11)
- ^ PhysOrg, "'Cosmic ghost' discovered by volunteer astronomer", Yale University, 5 August 2008 (accessed 2010-10-11)
Further reading
- Astrophysical Journal Letters, "The Sudden Death of the Nearest Quasar", Kevin Schawinski, Daniel A. Evans, Shanil Virani, et al., Volume 724, Number 1, Page L30, 1 November 2010, doi:10.1088/2041-8205/724/1/L30 , arXiv:1011.0427v1
- Astronomy and Astrophysics, "Hanny's Voorwerp - Evidence of AGN activity and a nuclear starburst in the central regions of IC 2497", Rampadarath, H.; Garrett, M. A.; Józsa, G. I. G.; et al., Volume 517, L8, July 2010, doi:10.1051/0004-6361/201014782 , Bibcode: 2010A&A...517L...8R
- Astronomy and Astrophysics, "Revealing Hanny's Voorwerp: radio observations of IC 2497", Józsa, G. I. G.; Garrett, M. A.; Oosterloo, T. A.; et al., Volume 500, Issue 2, 2009, pp. L33-L36, June 2009, doi:10.1051/0004-6361/200912402 , Bibcode: 2009A&A...500L..33J , arXiv:0905.1851