Talk:Quasar/Archive for 2011

Quasar size

"This implies that they are small (Solar System sized or less) because an object cannot change faster than the time it takes light to travel from one end to the other;"

Seems contradictory to me, because of:

1. Relativity of simultaneity (we can simultaneously observe very time-diverse actions)
2. Superluminous scissors (since "object changes" is not a signal propagation)
   Imagine a radiating parabola with focus of 1 light year. We are on the focal line between the arcs. When something "changes" in the focus, the subsequent changes will be both happening and seen on surface only one year after, though we will see them all-at-once.
   Dlazerka (talk) 19:35, 3 January 2011 (UTC)

I deleted this contradictory phrase. Dlazerka (talk)

Intrinsic Red Shift Controversy

• Quasar red shift is observed to be quantized. This means the Earth must be at the center of the universe in order for the Big Bang model to be true. Quantization is shown to be related to the harmonic 0.062 in quasar and galactic red shift. This harmonic finding has never been refuted to my knowledge. Arp notes that quantization becomes evident when a quasar cluster's red shift is transformed into the rest frame of the galaxy of origin.

• Quasars brightness does not correlate to their observed red shift as it does with galaxies. This refutes the notion of “expanding space” and the big bang. High red shift quasars can be well accounted for with known properties of light acting in the plasma vacuum of space.

Intrinsic Redshifts in Quasars and Galaxies Arp H., et al, Max-Planck-Institut fÄur Astrophysik, preprint 2010

Six Peaks Visible in the Redshift Distribution of 46,400 SDSS Quasars Agree with the Preferred Redshifts Predicted by the Decreasing Intrinsic Redshift Model Bell, M. B.; McDiarmid, D. The Astrophysical Journal, Volume 648, Issue 1, pp. 140-147. —Preceding unsigned comment added by 158.61.151.200 (talk) 19:58, 1 March 2011 (UTC)

Redshift periodicity in quasar number counts from Sloan Digital Sky Survey arXiv:0712.3833v2 [astro-ph]

The nature of QSO redshifts Stockton, A. ,ApJ, Part 1, vol. 223, p. 747-751, 753-757, 1 August 1978

Two emission line objects with z>0.2 in the optical filament apparently connecting the Seyfert galaxy NGC 7603 to its companion Lopez-Corredoira M. , Gutierrez C. M. ,Astron.Astrophys. 390 L15, 2002

Evidence for Intrinsic Redshifts in Normal Spiral Galaxies Russel D. G. ,Astrophys. & Space Sci.,Vol.298, No. 4, pp. 577-602, August 2005

Further Evidence for Intrinsic Redshifts in Normal Spiral Galaxies Russell D. G. ,Astrophys. & Space Sci.,Vol. 299, No. 4,pp. 387-403, October 2005

Discrete Intrinsic Redshifts from Quasars to Normal Galaxies Bell M. B ,arXiv:astro-ph/0211091v1 5 Nov 2002

Dynamic Multiple Scattering, Frequency Shift and Possible Effects on Quasar Astronomy Roy S. ,et al. ,arXiv:astro-ph/0701071v, January 2007

Propagation of light in low-pressure ionized and atomic hydrogen: application to astrophysics Moret-Bailly, J. IEEE Transactions on Plasma Science, 10.1109/TPS.2003.821476

--158.61.151.200 (talk) 20:05, 1 March 2011 (UTC)

Redshift quantization is very much a fringe view, and has been quite thoroughly refuted by modern surveys, such as the SDSS. In fact, the Redshift quantization page does a decent job covering this, though it could stand to be cleaned up. Suffice it to say, redshifts are not quantized, and the standard view that quasars are powered by accreting supermassive black holes in a Universe described by Lambda-CDM cosmology works just fine. Parejkoj (talk) 03:40, 3 March 2011 (UTC)

What Perjkoj said. The "quantization" is an artefact of the filament structure of the universe. Headbomb {talk / contribs / physics / books} 04:50, 3 March 2011 (UTC)

Can someone please explain this to me?

You are saying that: Applying Hubble's law to these redshifts, it can be shown that they are between 780 million and 28 billion light-years away
But the Universe's age is 13.7billion years. So this is a little paradox, how the light could travel 28billion years, if the light exists only 13.7billion years? Thats like Chuck Norris, who impregnated his own mother and built his own birthplace, isn't it? I don't say that it is not possible to exist so far, but we cannot see them, can we? And if we cannot see them, we cannot have the proof to prove that they are there, so we should use a word like PROPABLY.
95.105.216.200 (talk) 17:54, 12 April 2011 (UTC)

That is why the words proper distance are linked in that sentence. The "proper distance" is, roughly, where the objects in question are _now_, not where they were when they emitted the light we're presently seeing. --Christopher Thomas (talk) 18:51, 12 April 2011 (UTC)

Should be easier to understand

I know this is VERY scientific stuff, but can it be more.. easier to understand? After reading it, I still have no idea what a quasar is... PS: how come is says the size of it is 10-10000 the size of black holes? Saw from National Geographic channel that said black holes have a volume so small it is basicly 0... 10000 x 0 = still 0... so quasars are really small too? —Preceding unsigned comment added by 207.6.197.52 (talk) 23:56, 9 February 2011 (UTC)

The article actually says that the size is 10-10,000 times the Schwarzchild radius. The

Schwarzchild radius would be considerably larger than the actual radius of the black hole.--174.34.41.239 (talk) 22:27, 11 June 2011 (UTC)J28

Open questions and problems

1. "The highest redshift known for a quasar (as of December 2007) is 6.43, which corresponds to a proper distance of approximately 28 billion light-years from Earth"

It is an open problem, because age of the universe is approximately 15 billion years.

2. "and since quasars cannot continue to feed at high rates for 10 billion years, after a quasar finishes accreting the surrounding gas and dust, it becomes an ordinary galaxy"

It is very controversial thought. How this compact object (quasar) becomes an galaxy without explosion as Supernovas? — Preceding unsigned comment added by Prihod1 (talk • contribs) on 13:29, 25 April 2011

Both of these are already answered, very clearly, in the article. In addition, the distance quetion is answered in the thread right above this one. To briefly answer these again:

1. The distance given is the "proper distance". That's (roughly) where the quasars are now due to the expansion of the universe, which is farther away than where they were when the light was emitted. Light from them was coming towards us, while they were moving farther away from us. End result: More than 15 billion light-years away.

1. Quasars are not stars. They are active galactic nuclei - the glowing accretion disc and outflowing jets around a young galaxy's central black hole. A young galaxy has a lot of matter falling into the hole, so these features glow very brightly. When the galaxy settles down, much less matter is falling in, and the core of the galaxy is no longer a quasar.

The purpose of the talk page is to discuss how articles should be improved, not to answer questions that are already clearly explained in the article. Please bring further quetions to Wikipedia:Reference desk/Science instead of here. --Christopher Thomas (talk) 19:05, 25 April 2011 (UTC)

Artist's conception as first image

I think it is somewhat unsatisfying to have an artist's fantasy about a quasar as the first image. I might move it down further below in the article and set in a real image such as this one from the Hubblesite as first image: http://hubblesite.org/newscenter/archive/releases/1996/35/image/a/format/web_print/ Agge1000 (talk) 13:46, 20 November 2011 (UTC)

Some close-up quasars?

Uhh, are not relatively close-by galaxies such as M87 and Centaurus A (NGC 5128) now recognized as quasars? If so, would not that make necessary a reasonable number of changes to the article? Old_Wombat (talk) 11:00, 22 November 2011 (UTC)

No, although they do contain supermassive black holes (SMBH), those SMBH are not accreting a enough material to make them luminous enough to be called quasars. Not by many orders of magnitude. - Parejkoj (talk) 15:15, 22 November 2011 (UTC)

Hmmm. Let me get a couple of other expert opinions and I'll get back to you. Old_Wombat (talk) 06:25, 23 November 2011 (UTC)

Quasars have luminous accretion disks: radio galaxies like Cen A and M87 don't. There is an article on active galactic nuclei that discusses the nomenclature... Mhardcastle (talk) 07:45, 23 November 2011 (UTC)

Yes, agree with you on both counts. Suspect that my information may have been correct at the time but is now clearly outdated. Old_Wombat (talk) 07:42, 28 November 2011 (UTC)