Astronomers find first evidence of heavy black hole seeds in the early universe

[Admin]

The way in which supermassive black holes grew to tremendous sizes in the early universe has been a mystery for astronomers, but the puzzle could soon be solved.

Astronomers find first evidence of heavy black hole seeds in the early universe : Read more

 

[rod]

Very interesting reading. IMO, it still looks like SMBH in the early universe, remain challenging to explain using what we see operating in nature today, a very different nature operating *in the beginning*

I read another recent review on this OBG at the arxiv.org site.

Radio Emission From a z= 10.3 Black Hole in UHZ1, https://arxiv.org/abs/2308.03837

"The recent discovery of a 4 × 10^7 M⊙ black hole (BH) in UHZ1 at z= 10.3, just 450 Myr after the big bang, suggests that the seeds of the first quasars may have been direct-collapse black holes (DCBHs) from the collapse of supermassive primordial stars at z∼ 20. This object was identified in James Webb Space Telescope (JWST) NIRcam and Chandra X-ray data, but recent studies suggest that radio emission from such a BH should also be visible to the Square Kilometer Array (SKA) and the next-generation Very Large Array (ngVLA). Here, we present estimates of radio flux for UHZ1 from 0.1 - 10 GHz, and find that SKA and ngVLA could detect it with integration times of 10 - 100 hr and just 1 - 10 hr, respectively. It may be possible to see this object with VLA now with longer integration times. The detection of radio emission from UHZ1 would be a first test of exciting new synergies between near infrared (NIR) and radio observatories that could open the era of z∼ 5 - 15 quasar astronomy in the coming decade."

The space.com reported "Potentially, heavy black hole seeds are black holes with masses around 40 million time that of our sun. They are believed to form from the direct collapse of a massive cloud of gas, unlike your typical black hole that's born when a massive star reaches the end of its life and collapses under its own gravity. Galaxies theorized to host such heavy black hole seeds are referred to as Outsize Black Hole Galaxies (OBGs)."

My note. *Direct collapse of a massive cloud of gas* is a different mechanism used than the other arxiv.org report where possible direct collapse of massive stars with redshifts near 20 is considered. These would likely be a massive Population III star, something not observed in nature, like the seed used in the space.com report, *a massive cloud of gas* to start forming SMBH seen and documented today.

Using Ned Wright cosmology calculator, https://lambda.gsfc.nasa.gov/toolbox/calculators.html

z=10.3, "The age at redshift z was 0.459 Gyr." "The light travel time was 13.263 Gyr." "The comoving radial distance, which goes into Hubble's law, is 9719.9 Mpc or 31.702 Gly."

At the comoving radial distance from Earth today, space is expanding 2.2371032E+00 or more than 2.2x c velocity using H0 = 69 km/s/Mpc.

 

[Unclear Engineer]

So, do they believe that gas clouds can collapse into black holes without igniting fusion and causing a star to form? Or does a star form, but inside an event horizon so we cannot see it? A big enough ball of gas could still be quite cold when it becomes a black hole, at least in theory. Does that seem to work out, practically, given the density fluctuations apparent in the CMBR?

 

[Torbjorn Larsson]

@Unclear Engineer: It's in the paper.

"Heavy seed models, on the other hand, propose the formation of 10^4 − 10^5 M⊙ seeds in several possible ways. First, heavy seeds could result from the direct collapse of pre-galactic gas disks (Loeb & Rasio 1994; Volonteri & Rees 2005; Lodato & Natarajan 2006; Begelman et al. 2006; Lodato & Natarajan 2007) leading on to growth transiting through the OBG stage (Agarwal et al. 2013). A second pathway involves rapid, amplified early growth of originally light seeds that may end up in conducive cosmic environments, such as gas-rich, dense nuclear star clusters (Alexander & Natarajan 2014). Additionally, rapid mergers of light remnants in the early nuclear star clusters could also lead to the formation of heavy seeds at high redshifts as proposed by Devecchi & Volonteri (2009) as well as the runaway collapse of nuclear star clusters as proposed by (Davies et al. 2011). In addition to these more conventional theoretical seeding models, primordial black holes (PBHs, Hawking 1971) that form in the infant Universe have also been explored as potential candidates to account for the origin of initial seeds for SMBHs in the very early Universe (see Cappelluti et al. 2022 and references therein)."

The primordial black hole model directly from the weak cosmic background fluctuations are AFAIU disfavored by modern observations of the background as well as by microlensing (and other) observations not finding any.

 

[billslugg]

Sounds like a big enough cloud of primordial gas can collapse to a Black Hole without passing through the star stage, despite the outward pressure of the heat of compression.

 

[Unclear Engineer]

I understand that you saw an elliptically shaped, shiny silvery object. You believe that the sun glinting off a commercial jet aeroplane somehow was modified by a layer of moist air near you to create the appearance of a solid object.

Your explanation is certainly possible, and it is a good example of how atmospheric conditions can sometimes play tricks on our eyes. However, it is also possible that you saw something else entirely.
And in my experience, I know that I saw an actual thing not a UAP phenomenon I saw it very clearly and at that time of the night there were no jets or any aircraft flying around it was a clear dark night. I believe I saw something not made by a human.

Sounds like a big enough cloud of primordial gas can collapse to a Black Hole without passing through the star stage, despite the outward pressure of the heat of compression.

It seems like it would depend on how well separated the cloud became from other clouds, other masses. A not very dense but dimensionally immense gas cloud could be a black hole without collapsing. So if it eventually collapsed, those of us on the outside would not be able to witness it happen.

So, the question becomes is it realistic for a cloud to be dense enough, big enough, and separate enough to do that in the environment theorized for the universe following the release of the CMBR?

 

[Unclear Engineer]

Bill,

I think you accidentally quoted from 2 different threads when you replied to me here, then replied to each quoted subject in 2 successive posts in this thread.

The stuff about UAP observations belongs in the thread in the Astronomy Section https://forums.space.com/threads/a-night-of-wonder-my-unforgettable-ufo-encounter.62661/

 

[billslugg]

I see what happened. At 3:46PM y ou quoted Spacetime and inadvertantly included a UAP qoute to which I responded. I'll just delete my comment.