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Ngc 4178
NGC 4178 is a rather odd barred spiral in northern Virgo some 33 to 55 million light-years distant. Redshift puts it at 33 million light-years but the mean of Tully Fisher measurements puts it at 55 million light-years. Most agree it is a true member of the Virgo Cluster thus making the Tully Fisher distance most likely the more accurate. Members of the cluster often show high velocities, some so high they are blue shifted. Also the detail seen not only in my image but those of major scopes is consistent with the greater distance. NED shows it classified as SB(rs)dm HII. With the low redshift H alpha emission would be within the passband of my filter. I intended to take at least one image to see if I'd pick it up in the blue star clouds but weather never cooperated so that didn't happen.
Edit: The galaxy is rather unique in that it is the home of the smallest known supermassive black hole. See this link http://www.universetoday.com/98168/a...ve-black-hole/ for more information. The galaxy has a long central bar and no real central bulge. Only a hint of a spiral arm comes off the southern end of the bar while a weak on comes from the northern bar. Much of its disk is rather featureless with very little spiral structure. The only structure being provided by what appear to be randomly placed star clouds. The galaxy was discovered by John Herschel on April 11, 1825. It is also shows as discovered three quarters of a century later on September 6, 1900 by the German astronomer, Arnold Schwassmann, and listed as IC 3042. Being quite flat with little central bulge it made the 2 Micron Flat Galaxy Catalog as 2MFGC 09611. To the southeast is a "small" face on spiral about a billion light-years distant. Thus it is really quite large, about 145,000 light-years across in fact. It's only its great distance that makes it appear small. I've marked a star-like object as Q? in the annotated image that is south and a bit west of NGC 4178. NED's position has a 10 second error bar for a 21st magnitude quasar. This object is the only thing I see about 21st magnitude (20.7 by my reading) in the area. Certainly nothing else is in the area that is about that brightness. But it is about 18 seconds from the position shown for the quasar so not in the 10 second error bar. Checking the Sloan image shows nothing within the error bar's range down to 24th magnitude so I've marked the only possible candidate. Still the entire object may be erroneous so I've labeled it with a question mark for its identification being questionable. A quasar candidate (QC) is noted only about 1.5 billion light-years distant west of NGC 4178. It's PSF is that of a small disk galaxy not a quasar. The Sloan image shows a bright core in the center of a faint rather featureless disk galaxy same as my PSF indicates. One catalog at NED does say it is a galaxy, two a quasar and one an Ultra violet source. It certainly is some type of AGN but the quasar seems dim for one at that close distance. Four asteroids snuck into the image. Details are on the annotated image. One was moving very slowly making a very short trail in 40 minutes indicating it was caught just as it was changing from prograde motion to retrograde motion. 14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME http://www.spacebanter.com/attachmen...2&d=1416552923 http://www.spacebanter.com/attachmen...3&d=1416552938 http://www.spacebanter.com/attachmen...4&d=1416552947 Rick Last edited by WA0CKY : December 21st 14 at 06:50 AM. Reason: Additional information |
#2
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Ngc 4178
There is definately a problem with this post.
I see the three images decoded just fine, but I also get pieces of UUENCODE text in between the images. After examining the raw text, it appears a tail section of the encoded text got repeated somehow. If you look at the following image, I show the raw text and the decoded version side-by-side via screen captures. I am hosting the image on my own page to guarantee everyone being able to see the problem. Don't want your news clients trying to interpret the quoted code. I highlighted in orange the repeated text for clarity. http://www.skywise711.com/misc/WA0CKY-001.png It also happened to the second image in the post with about three times as many lines repeating. The last image does not have any repeat. BTW, WA0CKY/Rick, I really love the quality of your work, and the time you take to describe the images. Brian -- http://www.earthwaves.org/forum/index.php - Earth Sciences discussion http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Sed quis custodiet ipsos Custodes? |
#3
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Ngc 4178
Rick,
at first I thought "how could I have missed such a nice galaxy" until I noticed that it is at -20 degrees. Would have been in zenith in Namibia. Interesting to read about the "mystery object". Now if we could get Hubble to take a closer look... Stefan "WA0CKY" schrieb im Newsbeitrag ... NGC 4178 is a rather odd barred spiral in northern Virgo some 33 to 55 million light-years distant. Redshift puts it at 33 million light-years but the mean of Tully Fisher measurements puts it at 55 million light-years. Most agree it is a true member of the Virgo Cluster thus making the Tully Fisher distance most likely the more accurate. Members of the cluster often show high velocities, some so high they are blue shifted. Also the detail seen not only in my image but those of major scopes is consistent with the greater distance. NED shows it classified as SB(rs)dm HII. With the low redshift H alpha emission would be within the passband of my filter. I intended to take at least one image to see if I'd pick it up in the blue star clouds but weather never cooperated so that didn't happen. The galaxy has a long central bar and no real central bulge. Only a hint of a spiral arm comes off the southern end of the bar while a weak on comes from the northern bar. Much of its disk is rather featureless with very little spiral structure. The only structure being provided by what appear to be randomly placed star clouds. The galaxy was discovered by John Herschel on April 11, 1825. It is also shows as discovered three quarters of a century later on September 6, 1900 by the German astronomer, Arnold Schwassmann, and listed as IC 3042. Being quite flat with little central bulge it made the 2 Micron Flat Galaxy Catalog as 2MFGC 09611. To the southeast is a "small" face on spiral about a billion light-years distant. Thus it is really quite large, about 145,000 light-years across in fact. It's only its great distance that makes it appear small. I've marked a star-like object as Q? in the annotated image that is south and a bit west of NGC 4178. NED's position has a 10 second error bar for a 21st magnitude quasar. This object is the only thing I see about 21st magnitude (20.7 by my reading) in the area. Certainly nothing else is in the area that is about that brightness. But it is about 18 seconds from the position shown for the quasar so not in the 10 second error bar. Checking the Sloan image shows nothing within the error bar's range down to 24th magnitude so I've marked the only possible candidate. Still the entire object may be erroneous so I've labeled it with a question mark for its identification being questionable. A quasar candidate (QC) is noted only about 1.5 billion light-years distant west of NGC 4178. It's PSF is that of a small disk galaxy not a quasar. The Sloan image shows a bright core in the center of a faint rather featureless disk galaxy same as my PSF indicates. One catalog at NED does say it is a galaxy, two a quasar and one an Ultra violet source. It certainly is some type of AGN but the quasar seems dim for one at that close distance. Four asteroids snuck into the image. Details are on the annotated image. One was moving very slowly making a very short trail in 40 minutes indicating it was caught just as it was changing from prograde motion to retrograde motion. 14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME http://tinyurl.com/l7pkndd http://tinyurl.com/orvg7b6 http://tinyurl.com/p9hg4tm Rick -- WA0CKY |
#4
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Ngc 4178
"Skywise" schrieb im Newsbeitrag ... There is definately a problem with this post. It works fine in Outlook Express Maybe sometimes it is good to go with the mainstream ;-) Stefan |
#5
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Ngc 4178
"Stefan Lilge" wrote in :
"Skywise" schrieb im Newsbeitrag ... There is definately a problem with this post. It works fine in Outlook Express Maybe sometimes it is good to go with the mainstream ;-) I doubt it was my news client. I just deleted and redownloaded the post in question and it was fine. Anyway, it was the only time I personally had an issue, and it looks like it was just gremlims in the interwebz. Brian -- http://www.earthwaves.org/forum/index.php - Earth Sciences discussion http://www.skywise711.com - Lasers, Seismology, Astronomy, Skepticism Sed quis custodiet ipsos Custodes? |
#6
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Additional information added to the post I forgot to include originally.
Rick ____________ Quote:
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