Why do starburst galaxies 'burst'? ALMA sees super stellar nurseries at heart of sculptor galaxy

Why do starburst galaxies 'burst'?
What is the recipe for starburst? Astronomers studied NGC 253 with ALMA to find out. These new ALMA data reveal a diffuse envelope of carbon monoxide gas (shown in red), which surrounds stellar nurseries -- regions of active star formation (in yellow). By dissecting these regions with ALMA, astronomers are uncovering clues to the processes and conditions that drive furious star formation. The ALMA data are superimposed on a Hubble image that covers part of the same region. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ); A. Leroy; STScI/NASA, ST-ECF/ESA, CADC/NRC/CSA

Starburst galaxies transmute gas into new stars at a dizzying pace - up to 1,000 times faster than typical spiral galaxies like the Milky Way. To help understand why some galaxies "burst" while others do not, an international team of astronomers used the Atacama Large Millimeter/submillimeter Array (ALMA) to dissect a cluster of star-forming clouds at the heart of NGC 253, one of the nearest starburst galaxies to the Milky Way.

"All stars form in of dust and gas," said Adam Leroy, an astronomer formerly with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Virginia, and now with The Ohio State University in Columbus. "Until now, however, scientists struggled to see exactly what was going on inside starburst that distinguished them from other star-forming regions."

ALMA changes that by offering the power to resolve individual star-forming structures, even in distant systems. As an early demonstration of this capability, Leroy and his colleagues mapped the distributions and motions of multiple molecules in clouds at the core of NGC 253, also known as the Sculptor Galaxy.

Sculptor, a disk-shape galaxy currently undergoing intense starburst, is located approximately 11.5 million light-years from Earth, which is remarkably nearby for such an energetic star factory. This proximity makes Sculptor an excellent target for detailed study.

"There is a class of galaxies and parts of galaxies, we call them starbursts, where we know that gas is just plain better at forming stars," noted Leroy. "To understand why, we took one of the nearest such regions and pulled it apart - layer by layer - to see what makes the gas in these places so much more efficient at ."

ALMA's exceptional resolution and sensitivity allowed the researchers to first identify ten distinct inside the heart of Sculptor, something that was remarkably hard to accomplish with earlier telescopes, which blurred the different regions together.

Why do starburst galaxies 'burst'?
ALMA image of starbursting clouds inside NGC 253. The red region is the lower density CO gas surrounding higher density star-forming regions in yellow. Credit: B. Saxton (NRAO/AUI/NSF); ALMA (NRAO/ESO/NAOJ); A. Leroy

The team then mapped the distribution of about 40 millimeter-wavelength "signatures" from different molecules inside the center of the galaxy. This was critically important since different molecules correspond to different conditions in and around star-forming clouds. For example, carbon monoxide (CO) corresponds to massive envelopes of less dense gas that surround stellar nurseries. Other molecules, like hydrogen cyanide (HCN), reveal dense areas of active star formation. Still rarer molecules, like H13CN and H13CO+, indicate even denser regions.

By comparing the concentration, distribution, and motion of these molecules, the researchers were able to peel apart the star-forming clouds in Sculptor, revealing that they are much more massive, ten times denser, and far more turbulent than similar clouds in normal spiral galaxies.

These stark differences suggest that it's not just the number of stellar nurseries that sets the throttle for a galaxy to create new stars, but also what kind of stellar nurseries are present. Because the star-forming clouds in Sculptor pack so much material into such a small space, they are simply better at forming stars than the clouds in a galaxy like the Milky Way. Starburst galaxies, therefore, show real physical changes in the star-formation process, not just a one-to-one scaling of star formation with the available reservoir of material.

"These differences have wide-ranging implications for how galaxies grow and evolve," concluded Leroy. "What we would ultimately like to know is whether a starburst like Sculptor produces not just more stars, but different types of than a galaxy like the Milky Way. ALMA is bringing us much closer to that goal."

These results are accepted for publication in the Astrophysical Journal and are being presented February 15, 2015, at a news conference at the American Association for the Advancement of Science (AAAS) meeting in San Jose, California.


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Image: Hubble sees a swirl of star formation

Journal information: Astrophysical Journal

Citation: Why do starburst galaxies 'burst'? ALMA sees super stellar nurseries at heart of sculptor galaxy (2015, February 15) retrieved 21 October 2019 from https://phys.org/news/2015-02-starburst-galaxies-alma-super-stellar.html
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Feb 15, 2015
Why do starburst galaxies 'burst'?


Because the Birkeland currents which feed them are not static, the charge density fluctuates and can cause instabilities. The galactic "starburst" is equivalent to solar flares but on a much larger scale. No new physics need be required just a better understanding of the scalability of plasma processes.

Feb 15, 2015
Ok look, cantdrive 6 high votes just 40 minutes after making the comment. Blatant vote manipulation, which is really pathetic on a website where it doesn't matter.

Feb 15, 2015
I almost always have at least 3 votes shortly after I post a comment, see Cap'n Stupid, Viet killer, and baraklovin. I've got stalker trolls as well as my troll army. Go figure.

https://sciencex....5/?v=act

If you check out my rating it is obvious I could care less about it, contrary to my stalker trolls who think it has some meaning.

Feb 15, 2015
This isn't a popularity contest either. I'm far from high school.
The mainstreamers are convienced hot gas and gravity hold thd key, while others and myself, see something else that is scalable and reproduced in an actual laboratory. We don't rely on computer simulations and ad hoc mumbo jumbo.

Feb 16, 2015
Ok look, cantdrive 6 high votes just 40 minutes after making the comment. Blatant vote manipulation, which is really pathetic on a website where it doesn't matter.

And if you didn't notice, from the one who claims it doesn't matter, there is the pathetic gIMP's downvote...

Feb 16, 2015
This comment has been removed by a moderator.

Feb 16, 2015
If you check out my rating it is obvious I could care less about it,

Yeah. Erm. A slew of profiles, all registered within minutes of each other, and all without a single comment to their own name.

Uh huh. Riiiight. You don't care about the votes. Suuure. You may be fooling your own little brain, but I may have to break this to you: no one else is fooled.

Oh man. You are beyond pathetic.

Feb 16, 2015
Why do starburst galaxies 'burst'?


Because the Birkeland currents which feed them are not static, the charge density fluctuates and can cause instabilities. The galactic "starburst" is equivalent to solar flares but on a much larger scale. No new physics need be required just a better understanding of the scalability of plasma processes.

What is the source of said currents? You realise you need quite a powerful source - either electrical or secondary. Where is it and how does it look like?

Birkeland currents are usually given by solar winds and a magnetic field. The Sun is a secondary source of currents, as its main output is light.

Feb 16, 2015
So cantdrive? You're gonna do what all the others did (GhostOfOtto, Zephyr, ...) undermine your already non-existent credibility with a deliberate show of pettyness by mass sock-puppet voting?

Think that's gonna work better for you than it did for them? Really?
Well, at least it's a (not very original) method of admitting defeat on the issues on your part.

Meh. Whatever floats your boat: knock yourself out.

Feb 16, 2015
Why do starburst galaxies 'burst'?


Because the Birkeland currents which feed them are not static, the charge density fluctuates and can cause instabilities. The galactic "starburst" is equivalent to solar flares but on a much larger scale. No new physics need be required just a better understanding of the scalability of plasma processes.

What is the source of said currents? You realise you need quite a powerful source - either electrical or secondary. Where is it and how does it look like?

Birkeland currents are usually given by solar winds and a magnetic field. The Sun is a secondary source of currents, as its main output is light.

These currents are expected being the Universe consists of 99.999% plasma. A better understanding of the nature of plasma will do you right.
http://www.plasma...ratt.pdf

Feb 16, 2015
So cantdrive? You're gonna do what all the others did (GhostOfOtto, Zephyr, ...) undermine your already non-existent credibility with a deliberate show of pettyness by mass sock-puppet voting?

Think that's gonna work better for you than it did for them? Really?
Well, at least it's a (not very original) method of admitting defeat on the issues on your part.

Meh. Whatever floats your boat: knock yourself out.

Why am I not surprised you would fall for this obvious attempt of obfuscation by one of your fellow cheerleaders. This has Cap'n Stupid written all over it.

Feb 16, 2015

These currents are expected being the Universe consists of 99.999% plasma. A better understanding of the nature of plasma will do you right.
http://www.plasma...ratt.pdf

If two regions of plasma move nearby, then I think the currents will be induced near their boundaries. But if the plasma clouds are very large, they will attract gravitationally and run one into another. Then the kinetic effect may be larger than the one from the induced currents.

Do plasma jets from galactic cores induce currents that give rise to stars nearby?

Feb 16, 2015
This has Cap'n ...written all over it
@CD
why would i downvote AA_P, a PhD who has demonstrated a knowledge of physics, astrophysics and more, or another poster IMP who has repeatedly demonstrated a knowledge of astrophysics and both have presented factual arguments and supported their positions with links/references from reputable peer reviewed sources in the past?

and i would never upvote a known fallacious comment, especially when supported by a PSEUDOSCIENCE site

Nor would i report the posts and sockpuppets (like i already have, and suggest everyone else do) to admin because they can see IP addresses of the socks

It seems you are in collusion with ZEPHIR for sockpuppet army upvotes skewing the actual science, downvoting anything that is provable while upvoting the pseudoscience

this is just another typical attempt by pseudoscience acolytes to try to validate their religious like belief in their fallacies

period


Feb 16, 2015
Why am I not surprised you would fall for this obvious attempt of obfuscation by one of your fellow cheerleaders. This has Cap'n Stupid written all over it.

That's gotta be the dumbest rationalisation, ever. I mean: even for you that's dumb.

Pray tell: what would be the point and purpose of Stumpy to do this? Sockpuppet downvoting me so I would think you're an idiot? if you haven't figured out by now that that is my (and by the looks of it pretty much everybody's) opinion of you since...well...forever.
And what, much more, would be the point of him sockpuppet-UPVOTING you?

This explanation I just gotta hear.

Feb 16, 2015

These currents are expected being the Universe consists of 99.999% plasma. A better understanding of the nature of plasma will do you right.
http://www.plasma...ratt.pdf

If two regions of plasma move nearby, then I think the currents will be induced near their boundaries. But if the plasma clouds are very large, they will attract gravitationally and run one into another. Then the kinetic effect may be larger than the one from the induced currents.

Do plasma jets from galactic cores induce currents that give rise to stars nearby?

Plasma will always respond to and be dominated by EM forces, gravity has little if any effect even on a large "cloud". The collective effects of plasma are scalable just as are all plasma phenomena.

Yes, instabilities can and do form in jets.
http://amrel.obsp...H111.gif

Feb 16, 2015
Why am I not surprised you would fall for this obvious attempt of obfuscation by one of your fellow cheerleaders. This has Cap'n Stupid written all over it.

That's gotta be the dumbest rationalisation, ever. I mean: even for you that's dumb.

Pray tell: what would be the point and purpose of Stumpy to do this? Sockpuppet downvoting me so I would think you're an idiot? if you haven't figured out by now that that is my (and by the looks of it pretty much everybody's) opinion of you since...well...forever.
And what, much more, would be the point of him sockpuppet-UPVOTING you?

This explanation I just gotta hear.

For exactly the reason you bring up, to question credibility. However, this is an anonymous public discussion forum, I could really careless whether anyone thinks I have any credibility or not. For some, all that is needed to engender new perspectives is a simple thought or idea. That is my only goal, others will stop at nothing obfuscate such a notion.

Feb 16, 2015
It seems you are in collusion with ZEPHIR for sockpuppet army upvotes skewing the actual science, downvoting anything that is provable while upvoting the pseudoscience


You are a moron, your silly little voting agenda nor your belief of conspiracy does nothing to skew science or pseudoscience. Clearly it is yourself who is the religious acolyte which clings to the theologically based BB cosmology.

Feb 17, 2015
I did some plasma cosmology reading and while the general idea is very entertaining (imagine huge currents going randomly through space, maybe one day hitting us), I don't find it realistic at all. A permanent current that runs for billions of years needs a source of voltage (or electric field) that runs for that much. Such a current would be seen as a huge electric arc in space, not just some light globules here and there; it would pinch all over its length. Or maybe its source would be alternating. Now plasma may generate currents, but plasma also has fluctuations which prevent the apparition of large scale stationary currents. You don't see a permanent lightning in plasma going on for a very long time.

On the other side, gravitation is not affected much by fluctuations, since it is a purely attractive force - as far as we came to know it. Gravitation would dominate on large scales, while electromagnetism would be strong on small scales, IMO.

Feb 17, 2015
A permanent current that runs for billions of years needs a source of voltage (or electric field) that runs for that much.

First, no one is claiming these currents as being permanent, however when plasma is scaled to galactic or stellar proportions so too must the time frame of these occurrences by scaled to galactic or stellar dimensions.
Such a current would be seen as a huge electric arc in space

Plasma operates in three modes depending on current density, arc mode such as lightning, glow mode such as aurora, and dark mode such as the Earth's Birkeland currents.
Now plasma may generate currents, but plasma also has fluctuations which prevent the apparition of large scale stationary currents.

Yet strangely, we have measured these currents...
http://arxiv.org/...97v3.pdf

And there is a physical aspect that is often overlooked...

http://www-pub.ia...p_17.pdf

Feb 17, 2015
@cantdrive

You picked a strange link(http://arxiv.org/...7v3.pdf) to support EU. The model proposed in that study concerns jets created by black holes and yet according to EU black holes don't exist.

How to do you spin yourself out of that?

Feb 17, 2015
For exactly the reason you bring up, to question credibility.

So let me get this straight: he upvotes you (which he didn't) BEFORE I even read/commented on the article in order to undermine your (nonexisten) credibilty with me?
That's insane. That's so far down insanity road that even you must see it.

No. You just sockpuppeted and now you're caught in your own web of lies. You, sir, are really the pits.

For some, all that is needed to engender new perspectives is a simple thought or idea. That is my only goal,

Keep trying. Maybe you'll have one some day.
Or - god forbid - one of the innumerable good ideas in the published articles actually engender a new perspective in you? But I guess you're immune to your own method, aren't cha?

Feb 17, 2015
I could really careless whether anyone thinks I have any credibility or not
@CD
that is obvious considering that your typical response to ANY astrophysics claim is to post your eu pseudoscience
and then continually spread lies about the education of astrophysicists
(which you've never once been able to prove, and repeatedly been disproved & debunked)
to engender new perspectives is a simple thought or idea. That is my only goal
No, if this was your goal, you would not defend the non-defendable pseudoscience but support the proven science (di i need to bring up grand canyon, moon craters and dust devils again?)
others will stop at nothing obfuscate such a notion
And again, you get it wrong: there are some who will continually point out your pseudoscience
that is not obfuscation of new ideas, it is pointing out that you are promoting pseudoscience

you are beginning to think like Zephir now!

....imagine that....

Feb 17, 2015
your silly little voting agenda nor your belief of conspiracy does nothing to skew science or pseudoscience
@CD
so you are saying that promoting pseudoscience as legitimate like you do does nothing to undermine actual provable and real physics and science?
really?
there are plenty of people running around here that refute that theory when they post... believing in your pseudoscience blindly even though you still cannot connect the dots or comprehend why your own pseudoscience is physically impossible, or proven to be fallacious (case in point: Grand Canyon, Mon craters and dist devils... again)
Clearly it is yourself who is the religious acolyte
mainstream science is supported by evidence and experimentation, not religion
also, i follow the evidence
and that is one reason you've never been able to CONVERT me to your religious beliefs

even though you flood with plenty of pseudoscience links to your eu sites

Feb 17, 2015
one last point to CD
For exactly the reason you bring up, to question credibility
I've always supported science
by that i mean actual science and not pseudoscience
I would not downvote AA_P because he normally posts from a position of science
proven science

and i would never upvote pseudoscience
especially not you, because i do not agree with the spreading of false information

If you want to do that, start a church
that is what churches are for... belief in something without evidence and tenets that are used to control others regardless of how nonsensical they might seem
and THAT is the essence of your eu pseudoscience


Feb 17, 2015
So far astronomers have not seen the birth of at least one star. This is the reason why I am so surprised from the title of the article. Yes they can imagine some things, but it is more useful to their conscience to adhere to reality. At least for those who do not considered speculation as profession.
@ren
hypocrisy at its finest

this coming from a religious acolyte supporting creationist diatribe

funny, so far i've never seen a single religious person give proof or evidence that would hold up in court that their deity was real, either.

same rules apply to you that apply to your denigration of astrophysicists, you know!
but it is more useful to their conscience to adhere to reality.
epic failure

isn't lying a sin to your religion?
yet you continue to do it publicly when presented with scientific data...

interesting tactic

Feb 18, 2015
Such unnatural resistance to the truth speaks only for emotional immaturity.
@Ren
that's what i've been telling you
i am glad you realise it now... finally you can realise that SCIENCE will always trump religion!
thanks
when I have never witnessed such a process. Such a theory can not be confirmed by reality.
oops, i spoke too soon

-you've also never witnesessed the process by which your body turns food into fecal matter
-nor have you witnessed your skin cells shedding and replacing
-nor have you witnessed the microscopic forensic transfers of evidence between you and your environment that can actually trace your historical movements
-nor have you witnessed certain processes which can show how radiation can determine a lot of things (like where you've lived, grew up, died, etc etc etc)

ALL based on KNOWN physics
and demonstrated through science
PROVEN in courts
but denied by your religion and your pseudoscience beliefs

Feb 24, 2015
I didn't realize science was on trial...although there are likely alot of fraud charges pending against gravity...
@reset
since the point was lost on you (and you've not seen the original post which i discussed this with ren months ago) then i should explain that:
the point is that even the court system, taking the definition of "science" and "the scientific method" saw that there was NO SCIENCE in the creation "science"movement

the creationist dogma and tenets is nothing more than a repeat of the 7th day Adventist movement prophetess and another crackpot from early 1900 who pushed his agenda

the scientist PZ Myers explains it all here: https://www.youtu...jWkVKyRo

and i noticed that given your pseudoscience beliefs yourself, you came directly to the aid of another conspiracy theorist

your posts are more validation of this study: http://www.ploson...tion=PDF

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