Dustin wrote:Thanks for today's image.
The vast symmetry of that galaxy makes my jaw drop.
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
The extreme symmetry of M104 is in itself proof that this galaxy is "quiet" as far as star formation goes.
Take a look at this SDSS image of basically "red and dead" galaxy NGC 4314 by David Hogg:
This regrettably small image shows you an almost all-yellow galaxy with a perfectly straight yellow bar, an oval bulge, a well-formed ring surrounding the bulge and two symmetrical spiral arms. Everything is perfectly symmetrical, and there is no trace of star formation anywhere in this galaxy except in a small ring around the nucleus.
Compare the symmetry of basically all "red and dead" NGC 4314 with the lack of symmetry in massively starforming large spiral galaxies M61, M99 and M101:
Not very symmetrical, richly starforming spiral M61. Credit: Adam Block.
Not very symmetrical, richly starforming galaxy M99. Credit: Donald P Waid.
Not very symmetrical, richly starforming galaxy M101. Credit: Jean-Charles Cuillandre.
In M104, by contrast, there is very little star formation, which is why the galaxy is so symmetrical. Even the dust lane is "quiet". In another edge-on galaxy with a lot more star formation, the dust lane is bubbling with "fountains", which are likely the remnants of supernovae or very strong stellar winds from young stellar clusters:
Credit: Jean-Charles Cuillandre.
Compare the dust lane in NGC 891 with the dust lane in M104 in Rob's image a few posts above mine.
Ann
[quote="Dustin"]Thanks for today's image.
The vast symmetry of that galaxy makes my jaw drop. :!:[/quote]
The extreme symmetry of M104 is in itself proof that this galaxy is "quiet" as far as star formation goes.
Take a look at this SDSS image of basically "red and dead" galaxy NGC 4314 by David Hogg:
[img]http://www.deepfly.org/TheNeighborhood/BarredSpiral-NGC-4314.jpg[/img]
This regrettably small image shows you an almost all-yellow galaxy with a perfectly straight yellow bar, an oval bulge, a well-formed ring surrounding the bulge and two symmetrical spiral arms. Everything is perfectly symmetrical, and there is no trace of star formation anywhere in this galaxy except in a small ring around the nucleus.
Compare the symmetry of basically all "red and dead" NGC 4314 with the lack of symmetry in massively starforming large spiral galaxies M61, M99 and M101:
[img2]http://astronomycentral.co.uk/wp-content/uploads/2010/01/M61.jpg[/img2]
Not very symmetrical, richly starforming spiral M61. Credit: Adam Block.
[img2]http://www.waid-observatory.com/images/m/M99-2003-03-07LRGB-Labeled-3.jpg[/img2]
Not very symmetrical, richly starforming galaxy M99. Credit: Donald P Waid.
[img2]http://apod.nasa.gov/apod/image/0303/m101_cfht.jpg[/img2]
Not very symmetrical, richly starforming galaxy M101. Credit: Jean-Charles Cuillandre.
In M104, by contrast, there is very little star formation, which is why the galaxy is so symmetrical. Even the dust lane is "quiet". In another edge-on galaxy with a lot more star formation, the dust lane is bubbling with "fountains", which are likely the remnants of supernovae or very strong stellar winds from young stellar clusters:
[img2]http://images.astronet.ru/pubd/2002/07/03/0001177614/ngc891_cfht.jpg[/img2]
Credit: Jean-Charles Cuillandre.
Compare the dust lane in NGC 891 with the dust lane in M104 in Rob's image a few posts above mine.
Ann