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Blue Cloud in visible light
2497 Origem: Wikipédia, a encyclopediaJump para: navegação, pesquisa IC 2497 dados de observação
Época J2000.0 [1]
Constelação Leo Minor [2]
Ascensão reta 09h 41m 04.076s [1]
Declinação +34 ° 43 '58,57 "[1]
Dimensão aparente (V) 0,390 "× 0,320" [1]
astrometria
Redshift 0.051633 [1]
outras denominações
IC 2497, LEDA 165538, IRAS 09380 +3457, 2MASX J09410407 3443585
IC 2497 é uma galáxia espiral [3] perto de Voorwerp a nuvem intergaláctica Hanny. [1]
IC 2497 é uma ex-quasar, cuja luz iluminava Voorwerp Hanny, que agora é um eco de luz do quasar que se extinguiu. [4] Está a 45,000-70,000 anos-luz (14,000-21,000 pc) distante de Voorwerp de Hanny. [5 ] o quasar "se desligou" em algum momento dos últimos 70.000 anos. [6] Isto revisa as teorias atuais de operação dos quasares, como o quasar é quiescient, fechando muito mais rápido do que se imaginava possível, [7] e é muito mais frio do que o previsto. [5 ] a galáxia é atualmente de 100 a 10.000 vezes menor do que era quando seu quasar queimava em Voorwerp Hanny. [8]Este quasar é atualmente o mais próximo quasar conhecido, sendo 730 milhões de anos-luz de distância, e aquele com a melhor vista da sua galáxia anfitriã [8]. O próximo quasar 3C 273 é ativo,estando a 1,7 bilhões de anos luz mais longe. [9]
Fonte Wikipedia
tradução Google translator e Gustavo Detthow
Blue Cloud
Credit http://www.sky-map.org/ Posted by Gustavo Detthow
2497
From Wikipedia, the free encyclopedia
| Observation data Epoch J2000.0 [1] | |
|---|---|
| Constellation | Leo Minor [2] |
| Right ascension | 09h 41m 04.076s [1] |
| Declination | +34° 43′ 58.57″ [1] |
| Apparent dimension (V) | 0.390' × 0.320' [1] |
| Astrometry | |
| Redshift | 0.051633 [1] |
| Other designations | |
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
Galaxy formation is significantly modulated by energy output from supermassive black holes at the centers of galaxies which grow in highly efficient luminous quasar phases. The timescale on which black holes transition into and out of such phases is, however, unknown. We present the first measurement of the shutdown timescale for an individual quasar using X-ray observations of the nearby galaxy IC 2497, which hosted a luminous quasar no more than 70,000 years ago that is still seen as a light echo in "Hanny's Voorwerp," but whose present-day radiative output is lower by at least two, and more likely by over four, orders of magnitude. This extremely rapid shutdown provides new insight into the physics of accretion in supermassive black holes and may signal a transition of the accretion disk to a radiatively inefficient state.
Credit Wikipedia and http://iopscience.iop.org/2041-8205/724/1/L30/
Kevin Schawinski1,2,18, Daniel A. Evans3,4,5, Shanil Virani1,2,6, C. Megan Urry1,2,6, William C. Keel7,19, Priyamvada Natarajan1,2,6, Chris J. Lintott8,9, Anna Manning7,19, Paolo Coppi1,2,6, Sugata Kaviraj8,10, Steven P. Bamford11, Gyula I. G. Józsa12,13, Michael Garrett12,14,15, Hanny van Arkel12, Pamela Gay16 and Lucy Fortson17
Hanny's Voorwerp (English pronunciation: /ˈhɑːn.nis ˈvoʊr.wærp/), Dutch for Hanny's object,[1] is an astronomical object of unknown nature. It was discovered in 2007 by Dutch school teacher Hanny van Arkel, while she was participating as an amateur volunteer in the Galaxy Zoo project. Photographically, it appears as a bright blob close to spiral galaxy IC 2497 in the constellation Leo Minor.
Hanny's Voorwerp and IC 2497
Star birth is occurring in the region of the object that faces IC 2497. Radio observations indicate that this is due to an outflow of gas arising from the IC 2497's core which is interacting with a small region of Hanny's Voorwerp to collapse and form stars. The youngest stars are several million years old.[2]
A picture of the object appeared on the Astronomy Picture of the Day website[3] in data taken by Dan Smith (Liverpool John Moores University), Peter Herbert (University of Hertfordshire) and Chris Lintott (University of Oxford) on the 2.5 metre Isaac Newton Telescope.
One hypothesis suggests that it consists of remnants of a small galaxy showing the impact of radiation from a bright quasar event that occurred in the center of a nearby galaxy, IC 2497 about 100,000 years previously.[4] The quasar event is thought to have stimulated the bright emission that characterizes the voorwerp. The quasar may have switched off in the last 200,000 years,[2] and is not visible in the available images.
One possible explanation for the missing light-source is that illumination from the assumed quasar was a transient phenomenon. In this case, its effects on the voorwerp would be still visible because of the distance of several tens of thousands of light years between the voorwerp and the quasar in the nearby galaxy: the voorwerp would show a "light echo" or "ghost image,"[5] of events that are older than those currently seen in the galaxy.
On 17 June 2010, a group of researchers at the European Very Long Baseline Interferometry Network (EVN) and the UK’s Multi-Element Radio Linked Interferometer Network (MERLIN), proposed another related explanation.[6] They hypothesized that the light comes from two sources: a supermassive black hole at the center of IC 2497, and light produced by an interaction of an energetic jet from that black hole and the gas surrounding IC 2497.
The voorwerp and the neighboring galaxy are the object of active astrophysical research.[7] Observations of IC 2497 with the XMM-Newton[3] and Suzaku X-ray space telescopes to probe the current activity of the supermassive black hole have been arranged.[8]
Contents[hide] |
[edit] Description
The object, now referred to as a "voorwerp", is about the size of our Milky Way galaxy and has a huge central hole over 16,000 light years across. In the image, the voorwerp is colored green, a false color that is standardly used to represent the presence of several luminous emission lines of glowing oxygen. It has been shown to be at the same distance from Earth as the adjacent galaxy, both about 650 million light-years away.Star birth is occurring in the region of the object that faces IC 2497. Radio observations indicate that this is due to an outflow of gas arising from the IC 2497's core which is interacting with a small region of Hanny's Voorwerp to collapse and form stars. The youngest stars are several million years old.[2]
A picture of the object appeared on the Astronomy Picture of the Day website[3] in data taken by Dan Smith (Liverpool John Moores University), Peter Herbert (University of Hertfordshire) and Chris Lintott (University of Oxford) on the 2.5 metre Isaac Newton Telescope.
[edit] Hypotheses
One possible explanation for the missing light-source is that illumination from the assumed quasar was a transient phenomenon. In this case, its effects on the voorwerp would be still visible because of the distance of several tens of thousands of light years between the voorwerp and the quasar in the nearby galaxy: the voorwerp would show a "light echo" or "ghost image,"[5] of events that are older than those currently seen in the galaxy.
On 17 June 2010, a group of researchers at the European Very Long Baseline Interferometry Network (EVN) and the UK’s Multi-Element Radio Linked Interferometer Network (MERLIN), proposed another related explanation.[6] They hypothesized that the light comes from two sources: a supermassive black hole at the center of IC 2497, and light produced by an interaction of an energetic jet from that black hole and the gas surrounding IC 2497.
The voorwerp and the neighboring galaxy are the object of active astrophysical research.[7] Observations of IC 2497 with the XMM-Newton[3] and Suzaku X-ray space telescopes to probe the current activity of the supermassive black hole have been arranged.[8]
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