by Ann » Mon May 17, 2021 12:44 pm
NGC 891. Photo: Massimo Tuninetti.
What, the Color Commentator is posting a picture of NGC 4565 in black and white? Yes, because I wanted to emphasize how extremely long and thin the disk of this galaxy really is. Compare it with the similarly edge-on galaxy NGC 891, whose disk looks (and is, I'm sure) much smaller. Admittedly, the pictures aren't directly comparable, because they have been taken with different cameras, filters and exposure times, and they have been processed differently. Even so, the disk of NGC 4565 really
is very flat and extensive!
NGC 4565 seems extremely "calm and undisturbed" to me. Nothing much is bothering this galaxy, which is why its disk has been able to grow so vast. And nothing much is happening "from within", either. There is not a lot of star formation going on in this "island universe". Compare the appearance of NGC 4565 with that of starburst galaxy NGC 4631. The difference is certainly striking!
There is the slightest hint of a warp in the huge disk of NGC 4565. That reminds me of a few other galaxies with warped disks:
So here we have both the Needle galaxy (NGC 4565) and the Twisted Sister (ESO 510-G13). So let's listen to "A needle pulling thread" from Sound of Music, and.... Well, I couldn't find anything I liked by Twisted Sister. Sorry!
Click to play embedded YouTube video.
Sew, a needle pulling thread.
Ann
[float=left][img3="NGC 4565. Source: https://spacepix.wordpress.com/2015/08/25/ngc-4565-needle-galaxy-april-15-2015/"]https://spacepix.files.wordpress.com/2015/05/3-17-2015-ngc-4565.jpg?w=479&h=311[/img3][/float][float=right][attachment=0]NGC 891 MassimoTuninetti.png[/attachment][c][size=85][color=#0040FF]NGC 891. Photo: Massimo Tuninetti.[/color][/size][/c][/float]
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What, the Color Commentator is posting a picture of NGC 4565 in black and white? Yes, because I wanted to emphasize how extremely long and thin the disk of this galaxy really is. Compare it with the similarly edge-on galaxy NGC 891, whose disk looks (and is, I'm sure) much smaller. Admittedly, the pictures aren't directly comparable, because they have been taken with different cameras, filters and exposure times, and they have been processed differently. Even so, the disk of NGC 4565 really [i][b]is[/b][/i] very flat and extensive!
[float=left][img3="NGC 4565, an edge on galaxy with little star formation. Photo: Ken Crawford. "]https://upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Needle_Galaxy_4565.jpeg/1024px-Needle_Galaxy_4565.jpeg[/img3][/float][float=right][img3="Starburst edge on galaxy NGC 4631. Photo: R. Jay GaBany."]https://www.cosmotography.com/images/gabany-small_NGC4631_with_stream_and_new_satellites.jpg[/img3][/float]
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NGC 4565 seems extremely "calm and undisturbed" to me. Nothing much is bothering this galaxy, which is why its disk has been able to grow so vast. And nothing much is happening "from within", either. There is not a lot of star formation going on in this "island universe". Compare the appearance of NGC 4565 with that of starburst galaxy NGC 4631. The difference is certainly striking!
There is the slightest hint of a warp in the huge disk of NGC 4565. That reminds me of a few other galaxies with warped disks:
[float=left][img3="ESO 510-G13, a 'twisted sister galaxy' of the Milky Way. Photo: Hubble."]https://www.universetoday.com/wp-content/uploads/2011/04/twisted-sister-galaxy.jpg[/img3][/float][float=right][img3="Twisted Milky Way. I think they borrowed the bulge of NGC 4565 to serve as a a proxy for the bulge of the Milky Way. Maybe they used the disk of NGC 4565 too, and just twisted it a little? Illustration: OGLE/Warsaw University."]https://ichef.bbci.co.uk/news/976/cpsprodpb/122C1/production/_108133447_de27.jpg[/img3][/float]
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So here we have both the Needle galaxy (NGC 4565) and the Twisted Sister (ESO 510-G13). So let's listen to "A needle pulling thread" from Sound of Music, and.... Well, I couldn't find anything I liked by Twisted Sister. Sorry!
[float=left][youtube]https://www.youtube.com/watch?v=1RW3nDRmu6k[/youtube][c][size=85]Sew, a needle pulling thread.[/size][/c][/float] [float=right][img3="Twisted Sister. Sorry, they've been censored."]http://www.oif.ala.org/oif/wp-content/uploads/2018/04/censored-1726364_1280.jpg[/img3][/float]
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Ann