Starship Asterisk*

Ann wrote:

Dustin wrote:Thanks for today's image.
The vast symmetry of that galaxy makes my jaw drop.

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:
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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:
Ann

rstevenson wrote:

• The faint inner dust lanes may be tilted somewhat in relation to the overall plane of the galaxy, since the "top" of the galaxy appears to be dished somewhat yet the faint inner dust lanes can be easily seen below the near edge of the main dust ring. It looks to me as if those inner dust lanes are low in the near-left quandrant while being higher in the far-right quadrant.

rstevenson wrote:

owlice wrote:Rob, thanks for your image! Is it available in a larger size? If so, I'd like to see it. The Sombrero Galaxy usually looks more like a ring galaxy than a spiral to me; your reprocessing makes it look more like a spiral to me.

Here's a much larger one.

M104-ext-lg.jpg

This time I watched while I did the deed, and it's clear I'm losing a lot of the outer-most ring -- all of the darkest outer ring just disappears. That's because I'm dragging the brightness slider down to -100 (on a scale of 0 to 100) and the contrast slider to +50. Extreme, as I said. But it seems the only way to make those inner dust lanes come clear, at least it is if I start with the Hubble image as published. I suppose I might get better results if I worked on the original single-filter-at-a-time files, but I have no knowledge of how to do that or even where I might find the files to work with. Also, of course, different filters used to image the galaxy might be much better at revealing the dust while not being washed out by the glare of that central bulge.

Rob

nehushtan wrote:TMBG, famous for science in their music, has an oblique song which I believe is about this galaxy:

NoelC wrote:It's a gorgeous image of M104, but how many times does it really need a repeat showing? This one dates back to 2003. Yes, I see that the full-sized version is a little larger than it was back then.

Amateur (and even professional) astronomers from around the world are preparing new and uncommonly beautiful astroimages and submitting them for consideration as APOD. Why re-run any old images at all?

-Noel

Q4: Have some APOD pictures been run more than once?
A4: Yes. Many of our readers have been with us less than a year and are unaware of some really spectacular or important astronomy pictures. New information about old pictures is becoming available over the WWW. The text and links for rerun pictures will make use of this newly available information. So although the picture might be old, some of the text and links of each APOD will be new. Also, more web surfers have larger bandwidth connections, which allows us to post higher-resolution image files that can be transferred conveniently. Software to handle more sophisticated image file formats has also become more common, so the picture's size and/or format might be new. Lastly, rerunning APODs saves us time and helps us update our archive. In general, our rerun policy currently is to only rerun APODs more than one year old to keep the pictures relatively "new" to new APOD viewers. We will almost never rerun more than two pictures in any given week. So when you load the current APOD,it is still, most probably, a new picture.

hpfeil wrote:Infrared view of the dust lanes (spooky red eyes in larger images).
http://www.spitzer.caltech.edu/images/1 ... r-Sombrero

rstevenson wrote:Here's a much larger one.

hpfeil wrote:Infrared view of the dust lanes (spooky red eyes in larger images).
http://www.spitzer.caltech.edu/images/1 ... r-Sombrero

Dustin wrote:Thanks for today's image.
The vast symmetry of that galaxy makes my jaw drop.

neufer wrote:

'They usually come in pairs.'

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owlice wrote:Rob, thanks for your image! Is it available in a larger size? If so, I'd like to see it. The Sombrero Galaxy usually looks more like a ring galaxy than a spiral to me; your reprocessing makes it look more like a spiral to me.

• The dust lanes pile up near the outer edge, being much thinner the further in towards the center you go.
• The faint inner dust lanes may be tilted somewhat in relation to the overall plane of the galaxy, since the "top" of the galaxy appears to be dished somewhat yet the faint inner dust lanes can be easily seen below the near edge of the main dust ring. It looks to me as if those inner dust lanes are low in the near-left quandrant while being higher in the far-right quadrant.
• Developing (or dissipating) spokes can be seen in the far-right quadrant of the inner dust lanes.
• The thickest part of the main dust ring seems to be outside of the thickest part of the huge central bulge, almost as if the dust is gradually being pushed out. Or is it being drawn in?