Free Republic
Browse · Search
General/Chat
Topics · Post Article

Skip to comments.

WEBB Telescope Discovers Mysterious “LITTLE RED DOTS” at Cosmic Dawn
The Debrief ^ | July 2, 2024 | AVI LOEB

Posted on 07/03/2024 9:53:50 AM PDT by Red Badger

One of the surprising discoveries of the Webb telescope involves an early population of compact red galaxies at redshift above 7, a time when the Universe was 20 times younger than it is today. The galaxies are redder than expected from their cosmological redshift, indicating additional reddening by a layer of dust.

Some of these galaxies contain as much mass in evolved stars as our own Milky Way galaxy. Nevertheless, they are a hundred times smaller in radius, of an order of a few hundred light years. These compact galaxies manifest an increase by a factor of a million in the number of stars per unit volume relative to the Milky Way.

If we were to reside in such a galaxy, the solar system’s Oort cloud would have been stripped to a percent of its current size by the gravitational tide of passing stars. These tiny red rubies in the sky are commonly dubbed ‘little red dots.’

The mass in stars needed to light up these red galaxies requires, in the context of the expected abundance of galaxies in the standard cosmological model, that they convert nearly all their gas into stars rapidly over the hundreds of millions of years available to them after the Big Bang. Such full conversion is unlikely, suggesting that a significant fraction of their light is contributed by a central supermassive black hole.

The existence of a black hole in the little red dots is supported by spectroscopic detection of broad emission lines, representing outflows of gas with a speed of up to a percent of the speed of light, thousands of kilometers per second, as expected if the outflow originated from the immediate vicinity of a black hole.

Nevertheless, no X-rays have been detected as of yet from these galaxies, as typically observed from quasars. The required mass of the black hole is above expectations based on the correlation between the mass of stars and black holes in the present-day universe. What could be the possible origin of these little red galaxies, which might be pregnant with overmassive black holes in their bellies?

On the day that I arrived at Harvard University thirty years ago, a brilliant young student from the Physics department named Daniel Eisenstein showed up in my office and asked whether I would accept him as a graduate student. I promptly agreed and defined a research project for the two of us to explore. It involved a new idea that I had about the origin of quasars, the most massive black holes at the centers of galaxies. Back then, in 1993, the earliest quasars were observed from the ‘young adult’ Universe at a third of its current age.

My idea for seeding quasars in the infant Universe stemmed from the realization that the size of galaxies is dictated by their spin. The smaller the spin is, the more compact their final disk, where cold gas is held against gravity by rotation. The amount of rotation is derived from the tide the galaxies experience as their matter turns around from cosmic expansion and starts to collapse into a gravitationally bound system. Since different galaxies are born in different environments, their level of spin would be different, reflecting variations in the external tide.

These variations result in a probability distribution of galactic spins that Daniel and I calculated in a 1995 paper. We showed that this spin distribution is almost independent of galaxy mass or formation time. In a follow-up paper, we argued that a low-spin galaxy from the tail of the spin distribution would naturally host a compact disk of gas with less angular momentum than a typical galaxy. The gas from this compact disk would drain more efficiently towards the sink of a central black hole, seeding a quasar.

In addition, because of its small size, the gaseous disk in a low-spin galaxy would form stars more rapidly. We, therefore, suggested that low-spin galaxies could be the progenitors of quasar black holes.

When my bright postdoc, Fabio Pacucci, alerted me to the puzzling properties of the little red dots discovered by the Webb telescope, I was immediately reminded of my papers with Daniel. Fabio and I plan to explore the connection between the little red dots and low-spin galaxies more thoroughly in a future paper.

The scientific literature is vast, and I do not expect my colleagues to remember a paper written thirty years ago. Those of us with a long scientific memory must continue to connect the dots, literally speaking in this context of the ‘little red dots.’

In the grand scheme of academia, most papers are forgotten. But the most rewarding aspect of pursuing scientific knowledge is that data from nature eventually leads us to the truth even if the underlying ideas were proposed decades ago and are forgotten by now.

==============================================================

Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s – Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011-2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos,” both published in 2021. His new book, titled “Interstellar,” was published in August 2023.


TOPICS: Astronomy; History; Science; Society; Weird Stuff
KEYWORDS: astronomy; jwst; physics; science; stringtheory
Navigation: use the links below to view more comments.
first previous 1-2021-27 last
To: Red Badger

Must be lots of college kids pointing their laser pens at each other...


21 posted on 07/03/2024 2:31:21 PM PDT by SuperLuminal ( Where is Samuel Adams when we so desperately need him)
[ Post Reply | Private Reply | To 2 | View Replies]

To: Dead Corpse

“The Universe is far older than the current models imply.”

We don’t even know for sure if there was a “beginning” as we understand it.

The universe may be stranger than we can imagine.

Time may not play by human rules.


22 posted on 07/03/2024 2:33:56 PM PDT by cgbg ("Our democracy" = Their Kleptocracy)
[ Post Reply | Private Reply | To 6 | View Replies]

To: mlo

The goal posts keep moving as the telescope sees more and more....

It is time for the scientists to tell the truth, the whole truth, and nothing but the truth:

“We don’t know the answer.”


23 posted on 07/03/2024 2:35:27 PM PDT by cgbg ("Our democracy" = Their Kleptocracy)
[ Post Reply | Private Reply | To 19 | View Replies]

To: Red Badger

“ WEBB Telescope Discovers Mysterious “LITTLE RED DOTS” at Cosmic Dawn”

Webb telescope must have had a few too many on a really wild night out.


24 posted on 07/03/2024 3:14:09 PM PDT by Redcitizen
[ Post Reply | Private Reply | To 1 | View Replies]

To: Red Badger
WEBB Telescope Discovers Mysterious “LITTLE RED DOTS” at Cosmic Dawn

Possibly they've discovered the FIRST CASE of SPACE MEASLES!

25 posted on 07/03/2024 3:26:56 PM PDT by VideoDoctor
[ Post Reply | Private Reply | To 1 | View Replies]

To: Hot Tabasco

#15 We are on a microscope slide in a laboratory.
Or in a tub in Lisa’s bedroom....

The Simpsons - The Genesis Tub
https://www.youtube.com/watch?v=hISNhmvcEt8

Lutherans were created.
https://youtu.be/hISNhmvcEt8?t=95


26 posted on 07/03/2024 10:17:01 PM PDT by minnesota_bound (Need more money to buy everything now)
[ Post Reply | Private Reply | To 15 | View Replies]

To: alexander_busek

THANK YOU!!

The innumeracy shown by so many “writers” is grating.


27 posted on 07/04/2024 11:15:56 AM PDT by Don W (When blacks riot, neighborhoods and cities burn. When whites riot, nations and continents burn)
[ Post Reply | Private Reply | To 7 | View Replies]


Navigation: use the links below to view more comments.
first previous 1-2021-27 last

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
General/Chat
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson