Does the Milky have a QSO? What is the observational evidence concerning QSOs?

[betzalel]

There is a confusing article in the August, 2012 Scientific America concerning the recent discovery of a massive gamma radiation emission from the Milky Way galaxy, from the very recent past. As our solar system is one of the many members of the Milky Way this is an interesting subject.

If viewed from a distance galaxy, say M31, this massive gamma radiation emission would appear to be a Quasar, a QSO, a quasi-stellar object. As there are no QSOs in the local universe this presents an interesting puzzle. Why are there no QSOs in the local universe and how the heck can there be a QSO in the Milky Way?

To have an intelligent conversation concerning the Milky Way's hypothesized QSO it is necessary to review the observational evidence concerning QSOs. i.e. One can compare the toy model for QSOs to the observations and see if the observations match what is observed.


http://arxiv.org/pdf/1205.5852v1.pdf

Evidence for Gamma Ray Jets in the Milky Way
Although accretion onto supermassive black holes in other galaxies is seen to produce powerful jets in X-ray and radio, no convincing detection has ever been made of a kpc-scale jet in the Milky Way. The recently discovered pair of 10 kpc tall gamma-ray bubbles in our Galaxy may be signs of earlier jet activity from the central black hole. In this paper, we identify a gamma-ray cocoon feature in the southern bubble, a jet-like feature along the cocoon’s axis of symmetry, and another directly opposite the Galactic center in the north. Both the cocoon and jet-like feature have a hard spectrum with spectral index _ −2 from 1 to 100 GeV, with a cocoon total luminosity of (5.5 ± 0.45) × 10^35 and luminosity of the jet-like feature of (1.8 ± 0.35) × 10^35 erg/s at 1 − 100 GeV. If confirmed, these jets are the first resolved gamma-ray jets ever seen.

The mechanism by which jets turn on and off is one of the major puzzles in high energy astrophysics, and may be connected to star formation (Antonuccio-Delogu & Silk 2008). The relativistic jets inject significant amounts of energy into the medium within which they propagate, creating an extended, under-dense and hot cocoon. After decades of study, we still lack a complete understanding of the main mechanism launching, accelerating, and collimating jets, with limited knowledge of the energy content, the composition, and the particle acceleration mechanisms of the jets (Blandford & Znajek 1977; Blandford & Payne 1982)...

...The SMBH at the center of the Milky Way (MW) is surrounded by clusters of young stars and giant molecular clouds (Morris & Serabyn 1996). Although there are indications of past activity (Sunyaev et al. 1993), the SMBH is currently in a quiescent state. Despite the abundant observational evidence of large-scale jets in other galaxies, it was not expected that the Milky Way’s SMBH would produce such a relativistic collimated structure, given its current quiescence. However, the MW must have undergone phases of nuclear activity in the past in order for the SMBH to grow, and it is plausible that signs of past activity are still visible.

 

[Chalnoth]

There is a confusing article in the August, 2012 Scientific America concerning the recent discovery of a massive gamma radiation emission from the Milky Way galaxy, from the very recent past. As our solar system is one of the many members of the Milky Way this is an interesting subject.

If viewed from a distance galaxy, say M31, this massive gamma radiation emission would appear to be a Quasar, a QSO, a quasi-stellar object. As there are no QSOs in the local universe this presents an interesting puzzle. Why are there no QSOs in the local universe and how the heck can there be a QSO in the Milky Way?

Quasars are active galactic nuclei (AGN's). The nucleus of the Milky Way is not currently active. We do see the jets from previous activity, however.

I believe it is generally expected that the nuclei of galaxies become active when they first form, and when the galaxy undergoes a large disruption such as a merger with another galaxy.

And by the way, there are quite a few AGN's that are relatively close-by. The nearest is the nucleus of Centaurus-A, a mere 10-16 million light years away.

 

[betzalel]

Quasars are active galactic nuclei (AGN's). The nucleus of the Milky Way is not currently active. We do see the jets from previous activity, however.

I believe it is generally expected that the nuclei of galaxies become active when they first form, and when the galaxy undergoes a large disruption such as a merger with another galaxy.

And by the way, there are quite a few AGN's that are relatively close-by. The nearest is the nucleus of Centaurus-A, a mere 10-16 million light years away.

Thank-you for the correction.

Centaurus-A is also a gamma emitting AGN and is located 10 to 16 million light years away.

Very high energy gamma-rays from the radio galaxy Centaurus A

http://www.obspm.fr/actual/nouvelle/mar09/cena-f1.jpg

http://www.obspm.fr/actual/nouvelle/mar09/cena.en.shtml

 

[betzalel]

These are the papers I was thinking of. High luminosity quasars are no longer found in the local universe. This was assumed to be due to a difference in the feeding of the quasar due to a change in the environment from high redshift to the present.

As these two papers indicate. That belief is not correct.

The super massive black holes that power Quasars have down sized. At high redshift the most massive super massive BH is roughly 10^10 solar masses. In the local universe the most massive super massive black hole is 10^7 solar masses.

Our Milky Way super massive black holes is a growing baby massive object with an estimated mass of 3.6 10^6 solar masses.

It is interesting how our Milky Way super massive black hole and the other super massive BH holes in the local universe reach their plateau.

As this paper notes, as high redshift quasars must be very distant objects as they have high redshifts, then they must have a very massive super massive BH to produce the extraordinary high luminosity.

Those super large BH disappear and are no longer found in the local universe.

The spectral emissions of the Quasar curiously does not evolve with redshift.

As this paper notes, the authors of the paper do not know of any mechanism by which a super massive BH can lose significant mass, yet it appears based on observations that must have lost mass based on the assumptions and observations.


http://arxiv.org/abs/0902.3151v1

• Why have the masses of the observed central BHs decreased during cosmic epochs, from initial . 10^9.5 M⊙ to their present-day 10^7M⊙, as shown by the statistics of the SDSSurvey (fig.4, Vestergaard et al 2008)? • How could some of the most massive ones already form within . 0.8 Gyr after the Big Bang? • Why do their masses scale as 10^−2.85 times their bulge masses (Marconi and Hunt 2003)? • How do they blow their gigantic winds, and why have those winds the chemistry of ashes from excessive nuclear burning, being & 10^2-fold metal enriched (upto Fe)? • How do they generate their extremely hard spectra, (occasionally) peaking at &TeV energies, even recorded (from PKS 2155-304) as minute-sharp, hour-scale bursts (Weekes 2007), whilst accreting black holes radiating at their Eddington rates are predicted to shine with blackbody temperatures of KeV(M⊙/M)1/4? • Why are some of them distinctly underluminous? • Why does their high g -ray compactness not prevent them from forming jets, in the (10%) cases of their radio-loud subpopulation, via inverse-Compton losses?

• And, if all the astrophysical jet sources are generated by a universal type of engine – whose powerhouses are newly forming stars (like our Sun, in its past), forming (binary)white dwarfs, binary neutron stars, and AGN – this universal type of engine looks like a rotating magnet, not like a BH (Kundt and Krishna 2004).


FIGURE 4. (Estimated) mass distribution of 14,584 quasar central engines (CEs) with z ≥ 0.2, as functions of redshift z, from the Sloan Digital Sky Survey Data Release 3, within an effective sky area of 1644 deg2, taken from Vestergaard et al (2008). Squares denote median masses in each redshift bin. The dashed curve indicates faint SDSS flux limits.

An independent signature of the BD character of Sgr A* is its gigantic wind, seen to blow radial tails from the windzones of & 8 nearby stars, at distances . lyr, and mapped in the redshifted light of extended Br, and in the blueshifted light of Br, of mass rate some 10−2.5M⊙/yr, and speed . 103Km/s, (Kundt 1990). No hole can expel more matter than you dump on it.

http://iopscience.iop.org/1674-4527/12/3/002

On the non-evolution of the dependence of black hole masses on bolometric luminosities for QSOs

The main conclusion of our analysis is that both the mass and the Eddington ratio of the black holes for a QSO with a given luminosity do not evolve with redshift. Or in other words, the luminosity of a QSO does not evolve with redshift for a given mass. More precisely and considering systematic uncertainties _ 0:20:3 dex in the estimation of masses and luminosities, we conclude that the evolution in redshift, if any, is very small compared to the change in mean luminosity of the population of QSOs at low redshift with respect to such a population at high redshifts.

This implies an important result on the nature of QSOs, i.e. local QSOs are intrinsically less massive than QSOs at high redshift. Labita et al. (2009a) derived that the maximum mass of a black hole in a QSO is a function of the redshift: log10MBH = (0:34z + 8:99) M_ up to redshift 1.9, or proportional to (1 + z)^1:64 if extended up to a redshift of 4 (Labita et al. 2009b). This lack of the signature of active massive AGN black holes in the local Universe cannot be related with a possible decline in the rate of formation of QSOs (this would affect the density of QSOs but not their average mass; and indeed there is evidence for the change in the comoving density of QSOs of a given mass; Steinhardt & Elvis 2011, fig. 3), but because of some mechanism for the formation of huge black holes which took place in the past in the Universe, which is absent in the present Universe.

NOTE: Do not confuse the non-evolution of the black hole mass-luminosity ratio (the result of this paper) with the non-evolution of mechanisms which produce such black holes. Evidently, as said in the introduction, some evolution in the birth of new QSOs must take place in order to explain the absence of very bright QSOs at low redshift.

The existence of very massive black holes is only at high z. Perhaps it could be related with the higher ratio of mergers and then star formation in the past. We wonder whether it might have something to do with the excess of very massive galaxies at high-z, which is still not completely understood within semianalytical hierarchical _CDM models (e.g., Fontana et al. 2009). Indeed, the mass of the black hole has remained proportional to the stellar mass of their host galaxies for at least the last 9 Gyr (Jahnke et al. 2009). Or perhaps it has something to do with the larger average density of the Universe, or the angular momentum of some components of the galaxies (at high z, the black holes rotate faster; Netzer
2010).

However, where are the black holes with masses larger than 10^10 M_ which were frequent in the past? We do not know any mechanism by which black holes can reduce its mass.

 

[Chalnoth]

These are the papers I was thinking of. High luminosity quasars are no longer found in the local universe. This was assumed to be due to a difference in the feeding of the quasar due to a change in the environment from high redshift to the present.

As these two papers indicate. That belief is not correct.

Yes it is quite correct. The supposed discrepancies claimed by these papers are pretty trivially explained by two effects:
1. Selection: extremely massive black holes are going to be most visible when they are most luminous, i.e. at high redshift.
2. Volume: there is vastly more observable universe at high redshift than at low redshift, so that any exceptional regions in the universe are more likely to be at high redshift than low redshift.

 

[betzalel]

Yes it is quite correct. The supposed discrepancies claimed by these papers are pretty trivially explained by two effects:
1. Selection: extremely massive black holes are going to be most visible when they are most luminous, i.e. at high redshift.
2. Volume: there is vastly more observable universe at high redshift than at low redshift, so that any exceptional regions in the universe are more likely to be at high redshift than low redshift.

Chalnoth,

The explanation is not selection.

The mass of the central galactic BH can also be estimated by the size of the spiral galaxy bulge as there is a tight relation of the size of the spiral galaxy bulge to the mass of the central BH.

The anomaly is not only that high redshift quasars are more luminous.

The galaxy central BH get smaller with redshift (10^10 solar masses down to 10^7 solar masses). Downsizing of the central galaxy BH mass with redshift is anomalous, as there is no known mechanism by which a BH can lose significant mass. i.e. A 10^10 solar mass BH that formed at high redshift should be 10^10 or larger at in the local universe which is not observed. The 10^10 solar mass BH downsizes to 10^7 solar masses.

As the paper notes the spectral energy distribution of the quasar does not change with redshift which is also curious.

Metallicity also does not change with redshift which is also anomalous. One would expect metallicity should decrease with redshift. It does not.

http://arxiv.org/abs/0902.3151v1

• Why do their masses (bezalel: Galaxy central BH mass) scale as 10^−2.85 times their bulge masses (Marconi and Hunt 2003)?

 

[Chalnoth]

Chalnoth,

The explanation is not selection.

The mass of the central galactic BH can also be estimated by the size of the spiral galaxy bulge as there is a tight relation of the size of the spiral galaxy bulge to the mass of the central BH.

Extrapolating a poorly-understood empirical relationship with substantial variance far beyond where it is empirically-measured is not convincing.

The anomaly is not only that high redshift quasars are more luminous.

The galaxy central BH get smaller with redshift (10^10 solar masses down to 10^7 solar masses). Downsizing of the central galaxy BH mass with redshift is anomalous, as there is no known mechanism by which a BH can lose significant mass. i.e. A 10^10 solar mass BH that formed at high redshift should be 10^10 or larger at in the local universe which is not observed. The 10^10 solar mass BH downsizes to 10^7 solar masses.

I don't think you're getting it. Of course the higher-luminosity ones are going to be visible earlier: they're brighter! More dense regions will also form more quickly, and turn off more quickly. One of the things we're learning about quasars now is that they can very rapidly push away the material that would otherwise support their growth, and that means that if they are to get any significant amount of mass, it has to be done very quickly.

As the paper notes the spectral energy distribution of the quasar does not change with redshift which is also curious.

Metallicity also does not change with redshift which is also anomalous. One would expect metallicity should decrease with redshift. It does not.

The spectral energy distribution of AGN's varies dramatically from AGN to AGN. And their emission also tends to vary in time rather rapidly. The take away is just that AGN's are extremely variable objects, so that any apparent evolution of AGN environments is buried in the noise.

And these statements also don't surprise me at all, considering that AGN's aren't going to form until there's been a good amount of star formation in the area first.

 

[betzalel]

Extrapolating a poorly-understood empirical relationship with substantial variance far beyond where it is empirically-measured is not convincing.

The spectral energy distribution of AGN's varies dramatically from AGN to AGN. And their emission also tends to vary in time rather rapidly. The take away is just that AGN's are extremely variable objects, so that any apparent evolution of AGN environments is buried in the noise.

And these statements also don't surprise me at all, considering that AGN's aren't going to form until there's been a good amount of star formation in the area first.

You may be confusing variation in quasar luminosity with distribution of quasar spectral energy by frequency. QSO luminosity does very quickly and cyclically however the QSO spectral energy distribution continues to follow a power law.

The X-ray spectrum of QSOs shows a very simple spectral shape in the form of a power law, S υ = υ^- α where α≈ 0.7. The pattern of the QSO spectral energy distribution vs frequency is how Hawkins has able to show that QSOs do not show time dilation with redshift. This is the third paper that Hawkins has published that shows that QSOs do not show time dilation with redshift.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2010.16581.x/abstract
http://arxiv.org/abs/1004.1824

One of the quasar puzzles is how to generate jets, x-rays and gamma radiation that has spectral energy vs frequency that follows a power law, from an accreting disk and how to get the jet, x-ray and gamma radiation mechanism to turn on and off.

There appears to be connected, structured anomalies concerning the explanation of what is observed in this picture.

http://www.obspm.fr/actual/nouvelle/mar09/cena.en.shtml

This thread starts with the observation that the Milky Way super massive BH in the very recent past created gamma ray excited jets similar to this picture. The puzzle is the Milky Way is not merging with another galaxy. Why would the Milky Way in the recent past produce gamma ray exited jets?

http://arxiv.org/pdf/1205.5852v1.pdf

Evidence for Gamma Ray Jets in the Milky Way
Although accretion onto supermassive black holes in other galaxies is seen to produce powerful jets in X-ray and radio, no convincing detection has ever been made of a kpc-scale jet in the Milky Way. The recently discovered pair of 10 kpc tall gamma-ray bubbles in our Galaxy may be signs of earlier jet activity from the central black hole. In this paper, we identify a gamma-ray cocoon feature in the southern bubble, a jet-like feature along the cocoon’s axis of symmetry, and another directly opposite the Galactic center in the north. Both the cocoon and jet-like feature have a hard spectrum with spectral index _ −2 from 1 to 100 GeV, with a cocoon total luminosity of (5.5 ± 0.45) × 10^35 and luminosity of the jet-like feature of (1.8 ± 0.35) × 10^35 erg/s at 1 − 100 GeV. If confirmed, these jets are the first resolved gamma-ray jets ever seen.

The mechanism by which jets turn on and off is one of the major puzzles in high energy astrophysics, and may be connected to star formation (Antonuccio-Delogu & Silk 2008). The relativistic jets inject significant amounts of energy into the medium within which they propagate, creating an extended, under-dense and hot cocoon. After decades of study, we still lack a complete understanding of the main mechanism launching, accelerating, and collimating jets, with limited knowledge of the energy content, the composition, and the particle acceleration mechanisms of the jets (Blandford & Znajek 1977; Blandford & Payne 1982)...

...The SMBH at the center of the Milky Way (MW) is surrounded by clusters of young stars and giant molecular clouds (Morris & Serabyn 1996). Although there are indications of past activity (Sunyaev et al. 1993), the SMBH is currently in a quiescent state. Despite the abundant observational evidence of large-scale jets in other galaxies, it was not expected that the Milky Way’s SMBH would produce such a relativistic collimated structure, given its current quiescence. However, the MW must have undergone phases of nuclear activity in the past in order for the SMBH to grow, and it is plausible that signs of past activity are still visible.

As the Chandra x-ray paper notes the quasar x-ray spectrum does not evolve with redshift. The following is Kundt’s thoughts has to how to generate x-ray and gamma radiation that follows a power law.

• And, if all the astrophysical jet sources are generated by a universal type of engine – whose powerhouses are newly forming stars (like our Sun, in its past), forming (binary) white dwarfs, binary neutron stars, and AGN – this universal type of engine looks like a rotating magnet, not like a BH (Kundt and Krishna 2004).

http://arxiv.org/pdf/astro-ph/0503301v1.pdf

X-RAY LIGHTHOUSES OF THE HIGH-REDSHIFT UNIVERSE. II. FURTHER SNAPSHOT OBSERVATIONS OF THE MOST LUMINOUS Z ∼ > 4 QUASARS WITH Chandra
There is no indication of any significant evolution in the X-ray properties of quasars between redshifts zero and six, suggesting that the physical processes of accretion onto massive black holes have not changed over the bulk of cosmic time.

 

[Chalnoth]

You may be confusing variation in quasar luminosity with distribution of quasar spectral energy by frequency. QSO luminosity does very quickly and cyclically however the QSO spectral energy distribution continues to follow a power law.

No, I'm absolutely not mistaking the two. There is substantial variance in the actual emission spectra of quasars. See here:
https://www.google.com/search?q=qua...HJKea0QHPx4HwAw&ved=0CCAQsAQ&biw=1199&bih=626

The X-ray spectrum of QSOs shows a very simple spectral shape in the form of a power law, S υ = υ^- α where α≈ 0.7. The pattern of the QSO spectral energy distribution vs frequency is how Hawkins has able to show that QSOs do not show time dilation with redshift. This is the third paper that Hawkins has published that shows that QSOs do not show time dilation with redshift.

That's a different beast, because it's driven by the physics of the accretion disk. And I think you're really misunderstanding what that paper shows: redshift itself is time dilation. Hawkins was instead looking for time dilation due to the motion of the matter in the accretion disk. I'd have to look more into it to see what it implies about AGN's.

One of the quasar puzzles is how to generate jets, x-rays and gamma radiation that has spectral energy vs frequency that follows a power law, from an accreting disk and how to get the jet, x-ray and gamma radiation mechanism to turn on and off.

Right. AGN's are complicated beasts, and there's still a lot we don't know about them.

This thread starts with the observation that the Milky Way super massive BH in the very recent past created gamma ray excited jets similar to this picture. The puzzle is the Milky Way is not merging with another galaxy. Why would the Milky Way in the recent past produce gamma ray exited jets?

The Milky Way is currently merging with the Small and Large Magellanic clouds.

 

[twofish-quant]

As there are no QSOs in the local universe this presents an interesting puzzle. Why are there no QSOs in the local universe and how the heck can there be a QSO in the Milky Way?

I don't see the puzzle here. There is a supermassive black hole in the middle of the Milky Way. At some earlier time, that massive black hole was getting matter dumped into into producing massive amounts of gamma and X-rays. Now that the black hole has eaten up most of the gas, there's nothing left to produce a quasar.

A quasar is just an early phase of a normal galaxy.

One can compare the toy model for QSOs to the observations and see if the observations match what is observed.

As far as I can tell, it fits pretty well. Young galaxies have massive amounts of gas and dust at the core. This generates a continuous stream of radiation. As the galaxy eats up the gas, the radiation goes down. At some relatively recent time, a gas cloud got dumped into the black hole in the Milky Way generating a "last gasp" of gamma rays.

I don't see the mystery.

 

[twofish-quant]

The mass of the central galactic BH can also be estimated by the size of the spiral galaxy bulge as there is a tight relation of the size of the spiral galaxy bulge to the mass of the central BH.

1) I need to see references for this

2) I'd be extremely skeptical at extrapolating relations from one set of galaxies to another. If you can show references that show that there is a relationship between one set of galaxies, there's no particular reason why it should apply to early quasars.

As the paper notes the spectral energy distribution of the quasar does not change with redshift which is also curious.

I don't see any reason why it should. The spectral energy distribution is controlled by accretion disk physics and as long as you are feeding stuff in near the Eddington limit, you'd expect the spectral energy distribution to stay the same.

Metallicity also does not change with redshift which is also anomalous. One would expect metallicity should decrease with redshift. It does not.

Standard explanation is population III stars.

 

[twofish-quant]

One of the quasar puzzles is how to generate jets, x-rays and gamma radiation that has spectral energy vs frequency that follows a power law, from an accreting disk and how to get the jet, x-ray and gamma radiation mechanism to turn on and off.

The jet is a puzzle. The accretion disk, power law, and the energy generation mechanism aren't.

The puzzle is the Milky Way is not merging with another galaxy. Why would the Milky Way in the recent past produce gamma ray exited jets?

You dump in a large gas cloud into Sagattarius A.

• And, if all the astrophysical jet sources are generated by a universal type of engine – whose powerhouses are newly forming stars (like our Sun, in its past), forming (binary) white dwarfs, binary neutron stars, and AGN – this universal type of engine looks like a rotating magnet, not like a BH (Kundt and Krishna 2004).

1) First of all, the mystery is the jet. We don't have a good simple model for jets, and that's likely because we don't understand magnetic fields. People are working on this. We do have nice models for the disc and overall energy generation mechanism.

2) Black holes can generate rotating magnetic fields.

3) What you are describing is pretty standard. One thing that we are finding is that there is a lot of shared physics. You have a gravitational object, you dump stuff into that object. That object then emits jets and disks. You then have basically the same physics whether the central object is a star, a white dwarf, a neutron star, a stellar sized black hole, or a mega-black hole.

All of this stuff is "standard day at the office" stuff, and I'm not seeing where the mystery is.

 

[twofish-quant]

One other thing is that journal papers are terrible for trying to background knowledge. Journal articles assume that you already know the background for the thing that they are talking about.

The standard textbook for this sort of thing is...

http://www.cambridge.org/gb/knowledge/isbn/item1158688/?site_locale=en_GB

Also, I'm sure that is some good review paper out there that describes what the current state of research is, and if someone can point me do it, I'd be appreciative.

 

[betzalel]

I don't see the puzzle here. There is a supermassive black hole in the middle of the Milky Way. At some earlier time, that massive black hole was getting matter dumped into into producing massive amounts of gamma and X-rays. Now that the black hole has eaten up most of the gas, there's nothing left to produce a quasar.

A quasar is just an early phase of a normal galaxy.

As far as I can tell, it fits pretty well. Young galaxies have massive amounts of gas and dust at the core. This generates a continuous stream of radiation. As the galaxy eats up the gas, the radiation goes down. At some relatively recent time, a gas cloud got dumped into the black hole in the Milky Way generating a "last gasp" of gamma rays.

I don't see the mystery.

There are structured anomalies. A suite of mysteries.

Look at the SMBH mass' variance with redshift. Observationally it has been found that SMBH mass have a maximum mass at high redshift of 10^10 solar masses. The SMBH mass starts to down size at around z=2.5 and in the local universe the most massive SMBH is 10^7 solar masses. The question to answer is where did the SMBH mass go? (i.e. The galaxies we are observing at z less than 2.5 were formed when the universe was formed also.) SMBHs cannot based on their assumed nature loss significant mass.

A related issue is why do quasars' spectrum not exhibit time dilation with redshift? Super nova exhibit time dilation with redshift. (Could someone explain time dilation and why is occurs in the standard cosmological model, i.e. an expanding universe.)

As this paper also notes there are quasars with a SMBH mass of 10^10 solar masses 1 billion years after the formation of the universe. A basic back of the envelop calculation indicates even with accretion at the maximum theoretically possible that is not possible.
http://arxiv.org/pdf/0902.3151v1.pdf

See page 9 of the above paper link that has a copy of the graph from Vestergaard et al 2008 which from shows the SMBH (super massive Black hole) mass downsizes with redshift from 10^10 solar masses to 10^7 solar masses in the local universe. SMBH are not in allowed in the standard model to loss significant mass. Observationally, however, they do.
FIGURE 4. (Estimated) mass distribution of 14,584 quasar central engines (CEs) with z ≥ 0.2, as functions of redshift z, from the Sloan Digital Sky Survey Data Release 3, within an effective sky area of 1644 deg2, taken from Vestergaard et al (2008). Squares denote median masses in each redshift bin. The dashed curve indicates faint SDSS flux limits.

The AGN bulge scales at roughly 10^-3 to the SMBH mass. The better relationship SMBH mass to the velocity distribution of the AGN bulge.

Critical Thoughts on Cosmology Wolfgang Kundt

• Why have the masses of the observed central BHs decreased during cosmic epochs, from initial 10^9.5 M⊙ to their present-day 10^7M⊙, as shown by the statistics of the SDSSurvey (fig.4, Vestergaard et al 2008)?

• How could some of the most massive ones already form within 0.8 Gyr after the Big Bang?

• Why do their masses scale as 10^−2.85 times their bulge masses (Marconi and Hunt 2003)? Labita et al. (2009a) derived that the maximum mass of a black hole in a QSO is a function of the redshift: log10MBH = (0:34z + 8:99) M up to redshift 1.9, or proportional to (1 + z)1:64 if extended up to a redshift of 4 (Labita et al. 2009b). This lack of the signature of active massive AGN black holes in the local Universe cannot be related with a possible decline in the rate of formation of QSOs (this would affect the density of QSOs but not their average mass; and indeed there is evidence for the change in the comoving density of QSOs of a given mass; Steinhardt & Elvis 2011, fig. 3), but because of some mechanism for the formation of huge black holes which took place in the past in the Universe, which is absent in the present Universe.

NOTE: Do not confuse the non-evolution of the black hole mass-luminosity ratio (the result of this paper) with the non-evolution of mechanisms which produce such black holes. Evidently, as said in the introduction, some evolution in the birth of new QSOs must take place in order to explain the absence of very bright QSOs at low redshift.

 

[betzalel]

The observation that the quasar spectrum does not exhibit time dilation with redshift appears to be a paradox. The following is the third paper published by Hawkins which supports that conclusion. The paper includes possible solutions to solve the paradox.
http://arxiv.org/abs/1004.1824

On time dilation in quasar light curves
In this paper we set out to measure time dilation in quasar light curves. In order to detect the effects of time dilation, sets of light curves from two monitoring programmes are used to construct Fourier power spectra covering time-scales from 50d to 28yr. Data from high- and low-redshift samples are compared to look for the changes expected from time dilation. The main result of the paper is that quasar light curves do not show the effects of time dilation. Several explanations are discussed, including the possibility that time dilation effects are exactly offset by an increase in time-scale of variation associated with black hole growth, or that the variations are caused by microlensing in which case time dilation would not be expected.

1 INTRODUCTION
Time dilation (the stretching of time by a factor of (1 + z)) is a fundamental property of an expanding universe. Given the success of the the currently accepted cosmological model, which certainly implies expansion, it is perhaps surprising that more attention has not been paid to making direct measures of time dilation. This must surely be due in part to the fact that measures of time dilation can tell little or nothing about cosmological parameters within the framework of a Big Bang universe, but only whether or not the Universe is expanding. Also, it turns out to be surprisingly hard to formulate a conclusive test for time dilation. What is needed is an event or fluctuation of known rest frame duration which can be observed at sufficiently high redshift with an accuracy which enables the predicted stretching by a factor of (1 + z) to be observed.

5 INTERPRETATION OF RESULTS
The results of Section 4 provide strong evidence that the effects of time dilation are not seen in quasar light curves. This clearly runs against expectations based on a conventional cosmological viewpoint, and so in this section we examine ways in which the results may be understood.

http://arxiv.org/abs/astro-ph/0105073v1


This is the link to the 2001 paper that noted that quasars do not exhibit time dilation.
http://arxiv.org/abs/1009.3265v2

 

[Chalnoth]

http://arxiv.org/abs/astro-ph/0105073v1

The fact that this paper was never published and never cited should cause you pause (well, technically, it was cited once in a paper, but that appears to be a mistake because the reference in the text is no longer there).

This is the link to the 2001 paper that noted that quasars do not exhibit time dilation.
http://arxiv.org/abs/1009.3265v2

There is no mention of time dilation here.

 

[betzalel]

The fact that this paper was never published and never cited should cause you pause (well, technically, it was cited once in a paper, but that appears to be a mistake because the reference in the text is no longer there).


There is no mention of time dilation here.

Hi Chalnoth,
Perhaps my links were not correct. The following is a complete set of links both to the pre-print and to the published papers.

Hawkins is a quasar specialist. It seems he has proven unequivocally that quasars do not exhibit time dilation. That appears to be a paradox.

It is interesting to look at the downsizing of the quasar SMBH from high redshift where they are 10^10 solar masses to low redshift where they are 10^7 solar masses and to simultaneously think about the observation that quasars do not exhibit time dilation. There are two connected paradoxes. The lack of any redshift evolution of metallicity in the quasar spectrum is a third paradox. The inability to form a 10^10 solar mass SMBH when the universe was only 800 million years old is a fourth paradox.

It is very, very, unusual for a field of science that has sets of connected paradoxes in published papers. The quality of analysis of the observational data due to multi spectral analysis and surveys is outstanding in this field. It appears all or most of the observational data and analysis required to solve the problem is available. It is very, very, rare that a researcher has an opportunity to make multiple breakthroughs.

It is truly astonishing that someone has not written a review paper that connects the paradoxical observations as a set laying out the completing logical paths.

The observations (see other thread this forum) indicate that quasars are not turned on by mergers. Our own galaxy SMBH has turned on in the very recent past. Both of those observations indicate a galaxy's SMBH can turn on at all redshifts (The reason why SMBH are turning on is not known and needs an explanation.) The paradox (for the current quasar mechanism) is there are no observed 10^10 solar mass SMBH less than z=2. The SMBH mass can be determined both by luminosity of the quasar and by the velocity distribution of the AGN's bulge stars.

The standard model for BHs does not allow the SMBH to lose significant mass.

This is a link to the published 2001 paper.

http://iopscience.iop.org/1538-4357/553/2/L97/fulltext/015104.text.html

This is a link to the preprint of the published 2010 paper.

http://arxiv.org/abs/1004.1824

This the link to the published 2010 paper.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2966.2010.16581.x/abstract

On time dilation in quasar light curves
In this paper we set out to measure time dilation in quasar light curves. In order to detect the effects of time dilation, sets of light curves from two monitoring programmes are used to construct Fourier power spectra covering time-scales from 50d to 28yr. Data from high- and low-redshift samples are compared to look for the changes expected from time dilation. The main result of the paper is that quasar light curves do not show the effects of time dilation. Several explanations are discussed, including the possibility that time dilation effects are exactly offset by an increase in time-scale of variation associated with black hole growth, or that the variations are caused by microlensing in which case time dilation would not be expected.

1 INTRODUCTION
Time dilation (the stretching of time by a factor of (1 + z)) is a fundamental property of an expanding universe. Given the success of the the currently accepted cosmological model, which certainly implies expansion, it is perhaps surprising that more attention has not been paid to making direct measures of time dilation. This must surely be due in part to the fact that measures of time dilation can tell little or nothing about cosmological parameters within the framework of a Big Bang universe, but only whether or not the Universe is expanding. Also, it turns out to be surprisingly hard to formulate a conclusive test for time dilation. What is needed is an event or fluctuation of known rest frame duration which can be observed at sufficiently high redshift with an accuracy which enables the predicted stretching by a factor of (1 + z) to be observed.


5 INTERPRETATION OF RESULTS
The results of Section 4 provide strong evidence that the effects of time dilation are not seen in quasar light curves. This clearly runs against expectations based on a conventional cosmological viewpoint, and so in this section we examine ways in which the results may be understood.

 

[Chalnoth]

I see. That's a bit better. But there's basically no conceivable way this interpretation, that there is no time dilation, is accurate. The broadening of atomic spectral lines itself is proof positive of time dilation.

 

[Jonathan Scott]

I see. That's a bit better. But there's basically no conceivable way this interpretation, that there is no time dilation, is accurate. The broadening of atomic spectral lines itself is proof positive of time dilation.

Hawkins' paper describes observational results which very interestingly appear to contradict the expected result that quasar variability should show a time scale which correlates with the time dilation implied by the quasar's redshift, as there is no evidence of such correlation. Hawkins offers potential explanations such as the idea that the variation is caused by nearby effects in the line of observation, but this does not work very well and does not for example explain the observation that the variation of brighter quasars seems to be significantly slower than that of dimmer quasars, which suggests that the variation rate depends on the quasar's properties.

You can choose between the explanations offered by Hawkins, or you can offer your own, or you can question the results and methods used to obtain the observations, but I don't think that simply denying the content of the paper is a valid scientific approach!

I'd agree that broadening of atomic spectral lines is evidence of time dilation, but it does not prove that the time dilation is cosmological.

 

[Chalnoth]

Hawkins' paper describes observational results which very interestingly appear to contradict the expected result that quasar variability should show a time scale which correlates with the time dilation implied by the quasar's redshift, as there is no evidence of such correlation. Hawkins offers potential explanations such as the idea that the variation is caused by nearby effects in the line of observation, but this does not work very well and does not for example explain the observation that the variation of brighter quasars seems to be significantly slower than that of dimmer quasars, which suggests that the variation rate depends on the quasar's properties.

Or how about: AGN's are extremely variable sources whose properties are still pretty poorly-understood, and Hawkins is essentially just fitting to noise.

I'd agree that broadening of atomic spectral lines is evidence of time dilation, but it does not prove that the time dilation is cosmological.

That doesn't even make sense.

Edit: let me issue a correction, however. I did not mean broadening. Broadening is an entirely different effect that is usually due to local motions, but can also be caused by intervening plasma. I was merely talking about the redshifting of spectral lines.

 

[betzalel]

Hawkins' 2010 quasar time dilation paper has ten additional years of quasar data as compared to his 2001 quasar time dilation paper. Hawkins analysis methodology is standard. Hawkins is a senior quasar specialist.

Hawkins’ 2010 paper conclusion is that quasars do not exhibit time dilation which is a paradox. There are three other paradoxical observations noted in this thread that also support the assertion quasars do not exhibit time dilation.

The following is an explanation of the methodology and reasoning of Hawkins’ paper.

The quasar spectral energy distribution changes by a power law when the frequency of luminosity variation is plotted again power of the emission. Hawkins finds the power law by analyzing the data in the frequency domain which is a standard analytical technique. Hawkins’ finding is not new. The same finding is noted in textbooks. Hawkins finds, low redshift quasars when analyzed in the frequency domain tightly follow the power law.

Due to the expansion of the universe, there is a velocity difference between cosmologically distant objects and Earth based observers or any other distant observer. The velocity difference must - by general relativity - cause an observed slowing of events that occur on the distant object from the perspective of the Earth based distant observer.

Hawkins adjusted the distant quasar data in the frequency domain as appropriate to adjust for the time dilation phenomena that must occur for each high redshift quasar appropriately for the redshift of the quasar in question.

Hawkins finds that if the high redshift quasar data is adjusted for time dilation it no longer follows the power law which is a paradox.


http://arxiv.org/abs/1004.1824v1

3.2 Magnitude effects

A striking feature of the three SEDs (Spectral Energy Distribution) is the difference in the power law indices at high frequencies. It appears that there is a very marked decrease in the amount of short timescale variation as quasars become more luminous. The analysis of this intriguing result is beyond the scope of the present paper, but we note it here because of its possible effect on the measurement of time dilation, and will discuss it further in Section 4.

In order to measure the effects of time dilation we split the quasar light curves into low and high redshift samples. The idea was to compare the resulting SEDs to look for the expected shift of the high redshift sample towards longer timescales relative to the low redshift sample. Fig. 4 shows the low and high redshift SEDs separately, and it can be seen that in spite of the restriction in luminosity the SEDs are well defined, with excellent agreement between the different datasets where they overlap. The data are well fitted by the function P(f) in Eq. 2, and the fit parameters of interest are given in Table 1.

5 INTERPRETATION OF RESULTS
The results of Section 4 provide strong evidence that the effects of time dilation are not seen in quasar light curves. This clearly runs against expectations based on a conventional cosmological viewpoint, and so in this section we examine ways in which the results may be understood.

5.1 Black hole growth
Perhaps the most straightforward way of explaining the absence of the effects of time dilation in quasar light curves is to postulate an increase in timescale of variation associated with the growth of the central supermassive black hole of the AGN. Thus higher redshift quasars would contain less massive black holes which would vary more quickly in such
a way as to offset the effects of time dilation. The problem with this picture is that there is a well-supported correlation between black hole mass and luminosity based on reverberation mapping (Kaspi et al. 2000). This means that, given the restricted magnitude range of our sample, there can be little difference in the average black hole mass of the high and low redshift samples. Even if we ignore the restriction on luminosity, it would be difficult to cancel out time dilation effects by assuming an increasing luminosity with redshift as it is clear from Fig. 3 that the whole shape of the SED changes with luminosity, especially the power law index to shorter timescales. This is not what is seen in Fig. 5, where the shape of the SEDs does not change between high and low redshift samples.

 

[Chalnoth]

Given a total of six citations for that paper (according to NASA ADS), no, Hawkins is clearly not a major player in the field. I'm not seeing a single follow-up study, and the interpretation of AGN's not experiencing time dilation is simply impossible (since the time dilation is observed in the redshift itself).

My money is on this being down to an error made by Hawkins during the analysis.

 

[betzalel]

Given a total of six citations for that paper (according to NASA ADS), no, Hawkins is clearly not a major player in the field. I'm not seeing a single follow-up study, and the interpretation of AGN's not experiencing time dilation is simply impossible (since the time dilation is observed in the redshift itself).

My money is on this being down to an error made by Hawkins during the analysis.

It is a valid question: Is Hawkins a careful researcher, a senior quasar specialist.

The following is an arXiv search of Mike Hawkins’ recent publications (22 recent papers). It appears the statement that Mike Hawkins is a senior quasar researcher can be supported.

http://vo.astronet.ru/arxiv/index.php?get_articles=1&author=Hawkins, M

Here is a 2012 review book on quasar research. The contributors are a who’s who in quasar research. Mike Hawkins is a contributor.

http://rd.springer.com/chapter/10.1007/978-3-642-27564-7_7

Quasars in the Cosmic Environment
Mauro D’Onofrio, Paola Marziani, Jack W. Sulentic, Deborah Dultzin, Gordon Richards, Johan Knapen, Isaac Shlosman, Raffaella Morganti, Renato Falomo, Mike Hawkins, Alfonso Cavaliere, Ross McLure, Greg Shields, Hagai Netzer, Daniel Proga, Alberto Franceschini, Xiaoui Fan, Martin Elvis

This is Hawkins’ 1968 book on quasars for the general public.

https://www.amazon.com/dp/0738200379/?tag=pfamazon01-20

The following are some of the older Hawkins papers.

http://aas.aanda.org/index.php?opti...=129&url=/articles/aas/pdf/2000/09/ds7931.pdf

http://www.nature.com/nature/journal/v366/n6452/abs/366242a0.html

http://www.nature.com/nature/journal/v301/n5902/abs/301688a0.html

http://www.nature.com/nature/journal/v303/n5916/abs/303406a0.html

http://iopscience.iop.org/1538-4357/553/2/L97/fulltext/015104.text.html

 

[Chalnoth]

It is a valid question: Is Hawkins a careful researcher, a senior quasar specialist.

The following is an arXiv search of Mike Hawkins’ recent publications (22 recent papers). It appears the statement that Mike Hawkins is a senior quasar researcher can be supported.

http://vo.astronet.ru/arxiv/index.php?get_articles=1&author=Hawkins, M

...most of which are single-author papers. This is not a good sign. It's starting to look like Hawkins was once a careful researcher, but has since gone off the deep end.

 

[Chronos]

The mechanism responsible for quasar variability is unknown, so, it seems premature to suggest the apparent lack of time dilation in their periodicity should be considered a serious challenge to modern comology. I think Hawkins research is thorough and competent, but, insufficient to call into question the vast amount of data supporting current cosmological models.