Hubble watches baby galaxy in bloom

[tom_hobbes]

A nearby galaxy has been revealed to be an exceptionally late bloomer by the Hubble Space Telescope - forming its first stars billions of years after its peers. The galaxy's sluggish growth rate suggests it was born as a wispy gas cloud in a barren region of space, shortly after the big bang.<br /><br />Full story:<br /><br />http://www.newscientist.com/news/news.jsp?id=ns99996748 <div class="Discussion_UserSignature"> <p><font size="2" color="#339966"> I wish I could remember<br /> But my selective memory<br /> Won't let me</font><font size="2" color="#99cc00"> </font><font size="3" color="#339966"><font size="2">- </font></font><font size="1" color="#339966">Mark Oliver Everett</font></p><p> </p> </div>

 

[Maddad]

There are at least a dozen articles on the net about I Zwicky 18, but I stopped reading. The text of most of them is the same, so someone's passing a press release out to a bunch of different organizations.<br /><br />This galaxy is a puzzle. We know that it is no more than 500 million years old because of two observations: we see no stars in it that are older than that, and we see almost no elements heavier than helium in the interstellar gas. Why did the primordial gas cloud wait more than 13,000 million years before it collapsed into a star burst of creation? Whatever the answer, then why did it do it now?<br /><br />A galaxy like I Zwicky 18 ought to be way out on the edge of the observable universe, but insted it is only 45 million light-years away. That's sort of like deciding to go deer hunting and finding the buck standing on your front porch staring you in the face when you open your front door.<br /><br />The reason that I was reading all the stories on I Zwicky 18 is that I wanted to get an idea of how massive this irregular dwarf galaxy is. I had suspected that it was much smaller than our own Milky Way, and one side did confirm that in a picture captioin. I still though don't know how small is small. A million stars? A billion? *Shrugs* Anyone find out?

 

[alkalin]

I Zwicky 18 may not be very unusual, if we stop trying to think everything out there is somehow associated with big bang. There are many sorts of clusters in galaxies that have any sorts of ‘metalissity’ you can imagine.<br /><br />I hope you sense this article implies this galaxy started near the time of big bang. Does this bode well for the much larger and older galaxies? Just pretend they cannot exist because there is not enough time for them. So back to the math board!!<br />

 

[tom_hobbes]

Mad,<br /><br />It is a puzzle. Have you got any theories?<br /><br />If the galactic cloud was so nebulous that it took this long to begin forming stars, could there be others which simply dissipated over time? In this case would there have to have been some nearby, as yet unknown event which catalysed star formation?<br /><br />Could there be many more galaxies like this, yet to light up? (As noted this one is only five hundred million years into star formation and population III stars at that!). <div class="Discussion_UserSignature"> <p><font size="2" color="#339966"> I wish I could remember<br /> But my selective memory<br /> Won't let me</font><font size="2" color="#99cc00"> </font><font size="3" color="#339966"><font size="2">- </font></font><font size="1" color="#339966">Mark Oliver Everett</font></p><p> </p> </div>

 

[tom_hobbes]

I agree Steve, Hubble is still producing amazing results. It's a great shame. <div class="Discussion_UserSignature"> <p><font size="2" color="#339966"> I wish I could remember<br /> But my selective memory<br /> Won't let me</font><font size="2" color="#99cc00"> </font><font size="3" color="#339966"><font size="2">- </font></font><font size="1" color="#339966">Mark Oliver Everett</font></p><p> </p> </div>