New Image Reveals M33 is Bigger Than Thought (and it's Headed Our Way)
Written by Anne Minard
Image credit: NASA/JPL-Caltech/University of Arizona
NASA's Spitzer Space Telescope has captured this new image of M33, also known as the Triangulum Galaxy, and released it as part of the "Around the World in 80 Telescopes" event for the International Year of Astronomy.
Besides the pretty colors, the new image reveals something else about M33: it's more than meets the eye.
M33 is located about 2.9 million light-years away in the constellation Triangulum. It is a member of what's known as our Local Group of galaxies. Along with our own Milky Way and Andromeda, the group of about 50 galaxies travels together in the universe, bound to one another by gravity. In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space is expanding, causing most galaxies in the universe to grow farther and farther apart.
The new image reveals M33 to be surprising large – bigger than its visible-light appearance would suggest. With its ability to detect cold, dark dust, Spitzer can see emission from cooler material well beyond the visible range of M33's disk. Exactly how this cold material moved outward from the galaxy is still a mystery, but winds from giant stars or supernovas may be responsible.
The image is a three-color composite showing infrared observations from two of Spitzer instruments. Stars appear as glistening blue gems (several of which are actually foreground stars in our own galaxy), while dust rich in organic molecules glows green. The diffuse orange-red glowing areas indicate star-forming regions, while small red flecks outside the spiral disk of M33 are probably distant background galaxies.
As for the technical details, the blue parts of the image represents combined 3.6- and 4.5-micron light, and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.
Source: NASA's Spitzer site
Filed under: Astronomy, Spitzer, galaxies
Related stories on Universe Today
Comment policy: Be nice and brief. Don't advertise your stuff, or promote your personal theories. We'll delete any comments that break these policies. Click here for more details.
April 6th, 2009 at 8:41 am
M33 / NGC 598 * has a heliocentric radial velocity of -179+/-3 km.s^-1. In apparent diameter the size is roughly 71×42 arcmin or about 1.3×0.7 degrees. I think this is the infra-size. This visual size is about 66×38 arcmin. c.1.1×0.6 degrees – so the difference isn't that much different as the original press release implies. (A common problem these days in dumbing down all information as much as possible. Annoying none-the-less!)
Of course the flow models of this galaxy does not really apply, because the expansion is negligible at such proximity.
It is interesting to compare this with the cool images of the outer region from the same site at; http://www.nasa.gov/mission_pages/spitzer/multimedia/spitzerB-20090403.html
This shows the distribution of the dust referred too – and the regions beyond the visible disk at about 45K temperature (shown as a blue haze)
According to the J.L. Hinz et.al, article "Energy Sources of the Far-Infrared Emission of M33"; Astrophysical Journal Supplement Series, 154, 259 (Sep 2004) – the knowledge presented is therefore fairly old. (The original was presented on the 12th November 2001 – meaning it took another 2.5 years to get to print!!
Distance in this article comes from Freedman et.al. in 1991, giving 840 kiloparsecs from us. I think there are more recent estimates, but the radial velocity measured hasn't really changed since the 1980s. (Earlier studies before 2004 were made in 1984.)
Yet the most interesting thing to be determined is to find the source of how the dust is being heated – either by the more likely cosmic rays or as yet unobserved magnetic fields by polarimetry.
(Pity M33 is invisible to the telescopes in Antarctica, given in an earlier article in Universe Today last month.) Also in 2007 P.R. Tabatsabael, et.al. found "that the radio emissions is mostly non-thermal" beyond the central 5 kiloparsec core at 3.6cm and 20cm wavelengths. This makes this the most recent paper connected to the Spitzer image described here.)
Thanks for the lovely image though.
* Classification type of M33 the galaxy us SA(s)cd in classification.
April 6th, 2009 at 8:42 am
The source of the actual 2004 article that is mentioned above is at;
http://www.iop.org/EJ/article/0067-0049/154/1/259/60332.web.pdf?request-id=80fbbbfe-1348-401c-9742-dccf2b521a43
Cheers.
April 6th, 2009 at 9:32 am
Solacious B FRAUD…
You aren't the only one who can use Google or follow source links.
April 6th, 2009 at 9:38 am
Mr.Oblivious Says:
April 6th, 2009 at 9:32 am
"You aren’t the only one who can use Google or follow source links."
Oh dear. Can't you just say anything original?
Let's see, anything of your own to say, eh? No.
April 6th, 2009 at 12:43 pm
Mr.Oblivious Says:
"You aren’t the only one who can use Google or follow source links."
At least I can read.
April 6th, 2009 at 12:51 pm
As I understand it M33 is not credited with having a so-called "black hole" at it's center.
ScienceDaily reported on the lack of a "black hole".
Why did the reporter fail to mention this salient and supposed unique aspect of M33?
According to the hypothesis nearly all galaxies have "black holes", why would M33 not have a "black hole"?
Also, non-thermal radiation is detected as radio emissions, per: "Also in 2007 P.R. Tabatsabael, et.al. found “that the radio emissions is mostly non-thermal” beyond the central 5 kiloparsec core at 3.6cm and 20cm wavelengths."
Non-thermal radiation is also known as synchrotron radiation, a product of ultrarelativistic electrons spiralling through a magnetic field, aka, an electric current.
April 6th, 2009 at 2:55 pm
Salacious B. Crumb Says:
M33 is always my favorite and I thank you for getting me closer to the true size of this awesomely beautiful object.
April 6th, 2009 at 4:53 pm
You can also check out M 33 at many wavelengths at this site:http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/m33.html . Interesting to see how the appearance of a spiral galaxy changes drastically with wavelength.
April 6th, 2009 at 5:17 pm
Jon Hanford Says:
I thought I had much about M33, however the link you provided is awesome, thank you very much for the link!!!!!
April 6th, 2009 at 6:04 pm
Anaconda Says:
April 6th, 2009 at 12:51 pm
"As I understand it M33 is not credited with having a so-called “black hole” at it’s center.
ScienceDaily reported on the lack of a “black hole”.
Why did the reporter fail to mention this salient and supposed unique aspect of M33?"
Are you attempting to imply that the author somehow finds this possibility distasteful and chose to omit it, based upon an irrational drive to suppress the truth which is that gravity does not exist as it is currently understood? Gathering more evidence for proof of 'the great scientific cover-up' eh? Seriously – there are about a million interesting things you could say about this galaxy. Clearly they can't all be said in a 20 line blog post. Most people's interest in astronomy is a wee bit wider than your 'there must be something other than gravity' obsession.
"Non-thermal radiation is also known as synchrotron radiation, a product of ultrarelativistic electrons spiralling through a magnetic field, aka, an electric current."
Yeah – so? Synchrotron radiation is detected all over the place. That is not new – it has been known since the first radio telescopes were brought to bear on the sky. It seems that you feel that scientists deny that there is any form of electric current flowing in the universe at all. Of course this is not the case – any charged particle in motion can be thought of as an electric current, and hence any net motion of a group of charged particles is equally an electric current. Again – this is not new or surprising; there is an entire field called plasma astrophysics that deals with such things. I have worked with plenty of people at university who have studied such matters.
So electric currents exist in space. Every physicist/astronomer knows this. So again – so what? Your claim is that somehow these electric currents provide a net attractive force that either replaces or compliments gravity – an entirely different kettle of fish. And one that the mere presence of synchrotron radiation doesn't seem to support nor refute – i.e. it has little to do with it unless you can tie some particular property of the radiation in question to your theory and say "my theory quantitatively predicts this will happen, and it we see that it does." Then repeat with every observable aspect of our universe, and if your theory makes it through unscathed – you will win the Nobel!
April 6th, 2009 at 6:31 pm
@ Anaconda, what is your source or paper that claims that most galaxies in the universe have a Black Hole (I presume you are referring to Supermassive Black Holes) at their center? Dwarf galaxies are thought to be the most common type of galaxy in the universe, yet I know of NONE containing a SMBH. What about irregular galaxies? Some of them don't contain a nucleus at all. Cetainly SMBHs exist at the center of some galaxies, but what are your references?
April 7th, 2009 at 5:37 pm
@ Astrofiend:
You and the rest of the readers are free to draw your own conclusions.
I simply pointed out the fact and linked to a report to back up my statement.
Do you deny that it's significant that no so-called "black hole" is present in M33?
@ Jon Hanford:
Here is my reference.
Back to astrofiend — well, you acknowledge electric currents in space, which has been a lot more than many have been willing to admit — that's a start.
April 7th, 2009 at 6:39 pm
Is there a way to find out when Spitzer took this (and other) images? Would like to know when the photos originated.
April 8th, 2009 at 5:54 am
Solacious…
Anyone can read. It takes talent to post relevant original thoughts and conduct your own research.
BTW, research does not mean finding other peoples work and posting it.
April 8th, 2009 at 6:30 am
Oh Dear. the same dreary and irrelevant Oblivious is at it again!
Why is it I do all the saying and you say nothing by criticise.
You contribute zero, hence what you say means zero.
So either put up or shut up!
April 8th, 2009 at 8:25 am
The link you gave was to a press release about the finding and was clearly mistaken in its statement concerning BHs and galaxies. But that's not peer reviewed evidence. The published article this press release is based upon does NOT make any statements about the majority of galaxies in our universe containing SMBHs at their center. The paper even concluded an Intermediate Mass Black Hole (IMBH) of about 3000 solar masses may exist at the center of M 33. So it may have a BH at its center, too. Still need a reference to your claim that most galaxies have BHs at their center. If you're right, that's news to me and many others. Good luck!
April 8th, 2009 at 9:24 am
Jon Hanford:
"Feb 2, 2009 … Virtually all of these galaxies contain a black hole at their centers, that is, … The biggest galaxies have big, fluffy, low-density centers. … in galaxies: the most luminous galaxies harbor the most massive black holes. … a single more massive black hole at the center of the combined galaxy. … "
See press release, Astronomers Discover Links Between Supermassive Black Holes and Galaxy Formation (McDonald Observatory) University of Texas.
Hanford, I have to say, that in an age where the "press release" has substituted in many ways for scientific papers (a very mixed blessing in my estimation), I find your claim that you've never heard of the idea that so-called "black holes" are claimed to be at the center of almost all galaxies surprising, if not disingenuous.
This claim flies around the internet at a million miles an hour.
If you truly haven't heard of it, then I can't help you and you need to do a little research on your own.
Good luck.
April 8th, 2009 at 9:29 am
The whole concept of so-called "black holes" is garbage. It's something only "modern" astronomers, who drank the Kool-Aid at post-graduate shcool and their chanting acolytes believe in.
Most other people think they're all gogga.
April 8th, 2009 at 6:24 pm
The article states: "In fact, M33 is one of the few galaxies that is moving toward the Milky Way despite the fact that space is expanding, causing most galaxies in the universe to grow farther and farther apart."
Which are these few galaxies (or how many) – apart from Andromeda – and does this mean a collision/merger of all of them? When? This should be quite an event – I haven't read about it yet
April 8th, 2009 at 10:14 pm
RE: Anaconda
The Troll's Brain and MEMORY
April 9th, 2009 at 7:16 am
Salacious B. Dumb…
I have contributed plenty. However, I don't have your rediculous need to rant about every subject, in a lame attempt to appear intelligent.
Oooh.. look at Slacious the Crumb… who has such fantastic Google skills, and excels at plagarising data. Pitty he has no true research skills. So sad he can't actually retain the important information without having to look it up. Indignant, that he is so psychologically damaged, he has a need to rant more than Anaconda and Oills put together.
April 9th, 2009 at 7:20 am
@ Anaconda: : "Hanford, I have to say, that in an age where the “press release” has substituted in many ways for scientific papers (a very mixed blessing in my estimation), I find your claim that you’ve never heard of the idea that so-called “black holes” are claimed to be at the center of almost all galaxies surprising, if not disingenuous.
This claim flies around the internet at a million miles an hour." Yes, I've seen many 'press releases' claiming most galaxies have BHs at their centers, but NO peer-reviewed published papers stating this fact. Your last link was to another 'Press release' where the original paper referred to in the release was linked, mentioned only SMBH in BCGs. No conclusion was drawn that most galaxies have BHs at their centers. You still need to present peer-reviewed papers to back up your claim.
If you truly haven’t heard of it, then I can’t help you and you need to do a little research on your own.
April 9th, 2009 at 8:35 am
Mr.Oblivious
Oh dear is that really the best you can do?
Get some real help mate.
April 9th, 2009 at 3:07 pm
@ Salacious B. Crumb, and @ Mr.Obvious,
Hey, you guys — COOL IT!
We have enough trouble already with the likes of Anaconda and OilIsMastery, et al., contradicting mainstream science — "white is black" and "black is white" — without you two bickering like a couple of kids in the schoolyard.
April 10th, 2009 at 2:35 am
VAN3MAN Says:
"@ Salacious B. Crumb, and @ Mr.Obvious,
Hey, you guys — COOL IT!
We have enough trouble already with the likes of Anaconda and OilIsMastery, et al., contradicting mainstream science — “white is black” and “black is white” — without you two bickering like a couple of kids in the schoolyard."
Agreed, but try to get Oblivious to listen. He has some weird vendetta over knowledge, something to do with his own inadequacies. Anything I say he attacks (probably even this!)
He wants me to go silent, but I'll take absolutely no notice.
April 15th, 2009 at 11:05 am
Not that I'm impressed a lot, but this is more than I expected when I stumpled upon a link on Delicious telling that the info is awesome. Thanks.