NASA | MSFC | SAO | Chandra X-ray Observatory | 2016 Aug 10
[img3="Credits: X-ray: NASA/CXC/ETH Zurich/L.Sartori et al, Optical: NASA/STScI"]http://chandra.harvard.edu/photo/2016/ic2497/ic2497.jpg[/img3][hr][/hr]Two cosmic structures show evidence for a remarkable change in behavior of a supermassive black hole in a distant galaxy. Using data from NASA’s Chandra X-ray Observatory and other telescopes, astronomers are piecing together clues from a cosmic “blob” and a gas bubble that could be a new way to probe the past activity of a giant black hole and its effect on its host galaxy.
The Green Blob, a renowned cosmic structure also called “Hanny’s Voorwerp” (which means “Hanny’s object” in Dutch), is located about 680 million light years from Earth. This object was discovered in 2007 by Hanny van Arkel, at the time a school teacher, as part of the citizen science project called Galaxy Zoo.
Astronomers think that a blast of ultraviolet and X-radiation produced by a supermassive black hole at the center of the galaxy IC 2497 (only 200,000 light years away) excited the oxygen atoms in a gas cloud, giving the Green Blob its emerald glow. At present the black hole is growing slowly and not producing nearly enough radiation to cause such a glow.
However, the distance of the Green Blob from IC 2497 is large enough that we may be observing a delayed response, or an echo of past activity, from a rapidly growing black hole. Such a black hole would produce copious amounts of radiation from infalling material, categorizing it as a “quasar.” ...
Extended X-ray Emission in the IC 2497 – Hanny's Voorwerp System:
Energy Injection in the Gas around a Fading AGN - Lia F. Sartori et al
- Monthly Notices of the RAS 457(4):3629 (2016 Apr 21) DOI: 10.1093/mnras/stw230
arXiv.org > astro-ph > arXiv:1601.07550 > 27 Jan 2016