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ASTRO: Most fantastic Arp yet -- 143
Arp's catalog of strange galaxies is, of course, full of them but Arp
143 may be the strangest of all. It is listed in the NGC as two galaxies NGC 2444, above, and 2245 being the lower one. Most sources show 2444 as a S0 galaxy while 2445 is an irregular Magellan class galaxy. Arp however classed this as "material emanating from elliptical galaxies". Most consider this a colliding pair. NGC 2445 is the most distorted with what appears to be a rather normal spiral galaxy core surrounded by a soup of massive star formation and star clusters. I should have taken some H alpha data as I expect it would "light up" in that frequency. There's still time this year so I might give it a try if the snow ever stops. Red shift data shows them to be about 190 million light years away. Two other galaxies at that distance are also in the frame. To the east (left) is SDKs J074814.67+390244.8 which oddly enough is also classed as an irregular though it appears to me to be a barred spiral seen nearly edge on. To the right (west) is LEAD 21754 (CGCG 206-022). NED gives no classification for this obvious spiral while SIMBAD says it is simply a low surface brightness spiral. All of these appear to be members of the same group and may have interacted in the distant past. There are also three QSO's in the image. I've attached a second image marking them with their distance per NED (5 year WMAP data) in light travel time. An old photo of ARP 143 by the 200" Palomar scope is at: http://nedwww.ipac.caltech.edu/level...res/arp143.gif This field seems to contain more faint galaxies than any image I've ever taken. A search of the NED data base turned up 1700 galaxies brighter than my limiting magnitude within 15 arc minutes of the center of my image. My image is about 22x33 or about 80% of that size. So there are likely about 1300 galaxies in this image. Most are very faint and some may appear only on the raw FITS files. Any "star" you see that isn't nice and round is a galaxy and some that are round are as well, especially if the golden color of distant reddened galaxies. At the top a bit east (left) of center is a string of galaxies that range down below 22nd magnitude and are located over 2 billion light years away according to NED redshift data. Nearly all have a reddish color. This is most likely due to dust reddening as at that distance the light has passed through billions of light years of space. Above this chain is a faint fuzzy galaxy. It is far closer at only a couple hundred million light years as is the far brighter one directly west (right) of it. If I'd have realized there were so many faint fuzzies in this image I'd have used more exposure time. Even with my limited exposure this is, to me, the most fantastic image I've taken to date. Maybe not coffee table pretty, my flats were awful, but it sure blows my mind thinking about what all it contains. 14" LX200R @ f/10, L=4x10' RGB=2x10'. STL-11000XM, Paramount ME Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
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ASTRO: Most fantastic Arp yet -- 143
Rick,
this is a most interesting object indeed. And I like the "string" of galaxies near the top. Stefan "Rick Johnson" schrieb im Newsbeitrag ster.com... Arp's catalog of strange galaxies is, of course, full of them but Arp 143 may be the strangest of all. It is listed in the NGC as two galaxies NGC 2444, above, and 2245 being the lower one. Most sources show 2444 as a S0 galaxy while 2445 is an irregular Magellan class galaxy. Arp however classed this as "material emanating from elliptical galaxies". Most consider this a colliding pair. NGC 2445 is the most distorted with what appears to be a rather normal spiral galaxy core surrounded by a soup of massive star formation and star clusters. I should have taken some H alpha data as I expect it would "light up" in that frequency. There's still time this year so I might give it a try if the snow ever stops. Red shift data shows them to be about 190 million light years away. Two other galaxies at that distance are also in the frame. To the east (left) is SDKs J074814.67+390244.8 which oddly enough is also classed as an irregular though it appears to me to be a barred spiral seen nearly edge on. To the right (west) is LEAD 21754 (CGCG 206-022). NED gives no classification for this obvious spiral while SIMBAD says it is simply a low surface brightness spiral. All of these appear to be members of the same group and may have interacted in the distant past. There are also three QSO's in the image. I've attached a second image marking them with their distance per NED (5 year WMAP data) in light travel time. An old photo of ARP 143 by the 200" Palomar scope is at: http://nedwww.ipac.caltech.edu/level...res/arp143.gif This field seems to contain more faint galaxies than any image I've ever taken. A search of the NED data base turned up 1700 galaxies brighter than my limiting magnitude within 15 arc minutes of the center of my image. My image is about 22x33 or about 80% of that size. So there are likely about 1300 galaxies in this image. Most are very faint and some may appear only on the raw FITS files. Any "star" you see that isn't nice and round is a galaxy and some that are round are as well, especially if the golden color of distant reddened galaxies. At the top a bit east (left) of center is a string of galaxies that range down below 22nd magnitude and are located over 2 billion light years away according to NED redshift data. Nearly all have a reddish color. This is most likely due to dust reddening as at that distance the light has passed through billions of light years of space. Above this chain is a faint fuzzy galaxy. It is far closer at only a couple hundred million light years as is the far brighter one directly west (right) of it. If I'd have realized there were so many faint fuzzies in this image I'd have used more exposure time. Even with my limited exposure this is, to me, the most fantastic image I've taken to date. Maybe not coffee table pretty, my flats were awful, but it sure blows my mind thinking about what all it contains. 14" LX200R @ f/10, L=4x10' RGB=2x10'. STL-11000XM, Paramount ME Rick -- Correct domain name is arvig and it is net not com. Prefix is correct. Third character is a zero rather than a capital "Oh". |
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