This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Share this

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – brightrecruits.com can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today

Blog

How do supermassive black holes form?

greaves-495px.jpg
A supermassive black hole could look like this: but how did it form? (Courtesy: NASA)

By Hamish Johnston at the AAS meeting in Seattle

The universe is full of supermassive black holes (SBHs). Indeed, they make up the core of just about every galaxy. These monstrosities can be a billion times more massive than the Sun. But despite their size and ubiquity, astrophysicists don’t really understand how they are formed.

That was the topic of a fascinating talk by Mitch Begelman of the University of Colorado, who is an expert on SBH formation.

According to Begelman there are two competing theories – the small seed that takes a long time to grow, and the large seed that grows quickly.

The small seed refers to the collapse of a massive star of about 100–1000 solar masses to form a black hole that grows slowly by sucking in surrounding gas and merging with other structures until it is an SBH.

The large seed refers to the direct collapse of a huge cloud of gas to create a supermassive star that could be heavy as a billion Suns. According to Begelman, such stars would be very fragile and would only last a few million years until their cores collapsed to create a black hole.

But instead of exploding in a supernova like much smaller stars, the remaining matter would puff out to become a “quasistar” – resembling a red giant. This surrounding matter is rapidly sucked in and what remains is a black hole that Begelman believes could be as large as one million solar masses. This is around the lower limit of an SBH, and it could keep growing.

Sounds great, but is there any chance of seeing a supermassive star or quasistar?

Unlikely for supermassive stars, says Begelman, because they would be very hard to distinguish from clusters of hot stars. He is a bit more hopeful about quasistars, because they could stand out in the optical and infrared wavelengths. However, he concedes that this would be a tough job, even with the upcoming launch of the James Webb Space Telescope.

To paraphrase Begelman’s conclusion, SBH formation models are getting more sophisticated but the problem has not yet been solved.

This entry was posted in AAS January Meeting 2011. Bookmark the permalink.
View all posts by this author  | View this author's profile

One comment to How do supermassive black holes form?

  1. The bagless vacuums are the future in vacuuming
    your carpets and floors. One model that has defended the by-line of those
    with allergy, and has had individuals gushing about it
    is the Pisces S5280 Royal Blue Canister Vacuum Cleaner.
    You could place a larger rug in your main room; it
    could match the smaller one at the door or match the color of your walls or furniture.

Leave a comment

Your e-mail address will not be published. Required fields are marked *

Guidelines

  • Comments should be relevant to the article and not be used to promote your own work, products or services.
  • Please keep your comments brief (we recommend a maximum of 250 words).
  • We reserve the right to remove excessively long, inappropriate or offensive entries.

Show/hide formatting guidelines

Tag Description Example Output
<a> Hyperlink <a href="http://www.google.com">google</a> google
<abbr> Abbreviation <abbr title="World Health Organisation" >WHO</abbr> WHO
<acronym> Acronym <acronym title="as soon as possible">ASAP</acronym> ASAP
<b> Bold <b>Some text</b> Some text
<blockquote> Quoted from another source <blockquote cite="http://iop.org/">IOP</blockquote>
IOP
<cite> Cite <cite>Diagram 1</cite> Diagram 1
<del> Deleted text From this line<del datetime="2012-12-17"> this text was deleted</del> From this line this text was deleted
<em> Emphasized text In this line<em> this text was emphasised</em> In this line this text was emphasised
<i> Italic <i>Some text</i> Some text
<q> Quotation WWF goal is to build a future <q cite="http://www.worldwildlife.org/who/index.html">
where people live in harmony with nature and animals</q>
WWF goal is to build a future
where people live in harmony with nature and animals
<strike> Strike text <strike>Some text</strike> Some text
<strong> Stronger emphasis of text <strong>Some text</strong> Some text
WordPress Appliance - Powered by TurnKey Linux