Quasars Don't Show Time Dilation

Interesting.

My initial thought is that the brightness fluctuations of quasars is random, and I'm not sure how anyone can quantify this randomness enough to expect different signatures of randomness from near vs far away quasars. There may even be a fractal quality to this randomness, so that it would appear to be the same no matter what the relative speeds of the quasars are and no matter how much 'time dilation' may occur.

The article talks about light pulses. Quasars have 2 jets, like pulsars. It would seem that the quasar would have to rotate so that the jets would point to us at regular intervals to cause light flashes. I don't think I have heard of that.

"It would seem that the quasar would have to rotate so that the jets would point to us at regular intervals to cause light flashes. I don't think I have heard of that."

Haven't heard of that either. It is postulated that the quasars have intrinsic oscillations in light output, which are caused by gas/dust falling into the 'monstrous' central black hole. This process is however poorly understood, quite understandably if we consider the distances and rather small number of quasars observed so far.

I rather like Hawkins' idea of micro-lensing, perhaps caused by small primordial black holes created during the BB. Because of the movement of the Solar system, the quasar light might be dimmed and brightened as the small BHs move between us and the quasars, relatively speaking.

What's more, the brightness variations seem to be compatible with the number of small BHs needed to provide all the dark matter required by cosmology...

Wouldn't that be super cool?

-J

I saw the sentence about the light taking the same time to reach earth from the two distances, but didn't want to point it until comments were made.

It is postulated that the quasars have intrinsic oscillations in light output, which are caused by gas/dust falling into the 'monstrous' central black hole.

From the comments made, I think it's not a rotational pulse, but what you said above. The growth of the quasar could compensate for the time dilation. As for micro-lensing, dimming the light periodically with another black hole rotating around each of the 800 quasars seems to be a big stretch to me, but that may not be what he meant.

Does a black hole qualify as dark matter? I think you said it had to be non-barionic and transparent. Maybe matter would lose all qualities in that state, and would no longer be barionic.

"As for micro-lensing, dimming the light periodically with another black hole rotating around each of the 800 quasars seems to be a big stretch to me, but that may not be what he meant."

AFAIK, the majority of micro/mini black holes that could fluctuate quasar light intensity must essentially be in halo-orbits around our own Galaxy. Our movement relative to them will cause quasars to fluctuate in brightness.

"Maybe matter would lose all qualities in that state, and would no longer be barionic."

Primordial black holes that formed after inflation, but before nucleosynthesis happened, do qualify as dark matter, I think. If density fluctuations were "just right", ultra-hot (compressed) plasma/energy could have formed small black holes.

-J

Seems like every new discovery from deep space requires some tweaking of the Standard Cosmological Model. Some are not-so-minor tweaks. I suspect, as time goes on, we will eventually have to either revert to the old "shell within a shell" model, or come up with some new way of explaining observations more consistent with what is really out there...

The link is physicstoday.org, and the article is The echo of a dying quasar.

The physorg article is a relatively poor summary, containing at least one major blunder ("But even though the distant quasars were more strongly redshifted than the closer quasars, there was no difference in the time it took the light to reach Earth"); so it casts the story into a rather 'shadowy light'.

Nevertheless, here are the conclusions from the actual M. R. S. Hawkins paper:

"In this paper we have used Fourier power spectrum analysis of over 800 quasar light curves to measure timescales of variation at different redshifts. The expected effects of time dilation are absent, the SEDs [Spectral Energy Distributions] at high and low redshift being essentially identical. There seems to be no explanation for this within the conventional cosmological framework, and so various other possibilities are considered. These include the idea that the effects of time dilation are exactly offset by an increase in timescale of variation associated with black hole growth. Alternatively, the observed variations could be caused by microlensing, in which case time dilation would not be expected."

I suspect that there may perhaps be some problems with the spectral analysis or statistical techniques as well...

-J

Hi SG, I've resisted adding to your post as my knowledge of the subject is not all that good, but certain features catch my attention, and my input is inclined to be outside the box? I liked the idea that a black hole deteriorates into dark mater, something raised in the following artical. I am also attracted to the fact that quasars have long jets that extending out into pace, as a young man working as a marine engineer, I had the occasion to observe the odd behaviour of clouds. Sitting on deck with a clear blue sky overhead and a calm ocean, out of nowhere a cloud would start to appear over head, and shortly after disappear only to reappear on the horizon, with close observation one could see a thin line of a jet stream connecting them? That raised the idea in my head do you think that dark mater is bipolar?

"I liked the idea that a black hole deteriorates into dark mater, something raised in the following artical."

I don't think that's what your reference said. The apparent dark matter is smeared out over a large are near the center of the collision-cluster - the blue region in the picture of the ref. AFAIK, there is no evidence of black holes there.

Further, normal black holes are classified as baryonic (normal) matter, because they originated from massive stars that died. Dark matter does not fit into the baryonic matter 'budget', because not enough could have been made during the nucleosynthesis phase of the B/Bang. It had to be created before nucleosynthesis, but that is a long story, of which I only understand the barest essentials...

-J

I understand what you are saying about before nucleosynthesis, but...

Further, normal black holes are classified as baryonic (normal) matter, because they originated from massive stars that died.

I can't agree based on this and this.

"I can't agree based on this and this."

The problem they discuss is how to classify black holes because of the "no hair theorem". One can't check what 'went in' after the fact.

My point has more to do with black holes that formed from normal matter/energy and those that didn't (the potentially primordial stuff). The latter is a candidate for the dark matter, while the prior isn't - not enough could have been around, if theory is anywhere near correct.

-J

I've resisted adding to your post as my knowledge of the subject is not all that good

None of us know that much about quasars (or anything else in the heavens). Your comments will always be welcome. Thanks for the article. It said that " a mysterious "dark matter core" has been discovered in the aftermath of a massive galaxy cluster collision." That was not necessarily a result of the collision, but could have contributed if black holes qualify as dark matter. I liked this part:

Normally, they would have expected to find a little dark matter hanging around after the shake-up, clinging to the leftover galaxies. Instead they discovered an immense "dark core" that defies scientific theory. The majority of the galaxies had quickly moved away in opposite directions after the collision, but their dark matter remained..."This result is a puzzle," said astronomer James Jee of the University of California, Davis, leader of the Hubble study, according to the statement. "Dark matter is not behaving as predicted, and it's not obviously clear what is going on."

What a surprise. A thing that we know nothing about is not behaving as predicted. It could be that there are two (or more) types of dark matter. I get the impression that this one is repelling the galaxies, or at least not attracted to them.

I have one other observation. Dark matter I believe is considered to exist to explain why the planets on the outer edge of a galaxy hold their position, relative to other planetary systems, do not fly off into space due to their velocity, dark matter being used to explain a gravitational force to prevent that happening? as against a force that is causing the universe to expand holding them back in? or a combination of both?

My observation is, Galaxy's rotate on a plane made up of dark matter, a disk, and this disk is on a plane that is random when compared to other Galaxy's, why? If the universe was created by the Big Bang? would you not think that the plains that Galaxy's rotate about would be a lot more consistent? With regard to each other. This of cause assumes that the disk does not wobble, which if I push that idea further could be the reason why black holes flash at regular intervals?

Regards JD.

Galaxy rotation may be explained by here.