Sorry about the title typo. Arp 152 is the correct designation.

Arp 152 is one of the most famous Arp galaxies and often in the news. Here's a link to such a current news item. http://www.universetoday.com/2009/07...d-astronomers/ It has one of the universe's largest fireworks going off in its core, powered by a giant black hole. This creates the jet. It is the jet that put it in Arp's catalog of course. While we only think of M87 when galactic jets are mentioned Arp has 4 of them in his catalog. Two were well placed this spring and I hoped to image them along with M87 but thanks to the perpetual clouds this didn't happen. I've attached 3 different processing version of this one image; one processed normally except the core has been reduced to show the jet, one a closeup 2x enlargement of the core and jet region processed just for the jet and one that is annotated to show other galaxies in the field. The last is made from a very differently processed image to hold down bandwidth.

M87 is one of the anchor galaxies of the Virgo cluster. It's mass along with that of a couple other super massive elliptical galaxies seem to define the center of this cluster. One of these M49 was in a previous update. I've reduced the brightness of M87 considerably to allow the jet to be seen. I believe but can't prove that many of the star-like points around and within the the galaxy that make it appear to be in a faint star cluster are really some of its many globular star clusters.

The 2x enlargement of M87's core region is at 0.5" per pixel. The core is the star like point and the jet the linear feature pointing back to the core. Suspected globulars are seen in the enlargment, some quite oval others just irregular in shape. Some may be distant galaxies or field stars.

The field is rather interesting as it contains members of the Virgo cluster and many background galaxies. See the annotated image to identify the various galaxies. All with NGC or IC numbers as well as PGC41495 are members of the Virgo cluster and are thus about 50 to 60 million light years away. Many of the galaxies I have identified that are not cluster members have no red shift data that I was able to find. Those that do are listed below.

UGC7652 is a pair of galaxies. Not how red they are. They shine right through the stars of M87. This pair is 1.1 billion light years away.

The most distant galaxy in the image is SDSS J123013.96+122230.0 at 2.9 billion light years.

SDSS J123152.76+122824.9 which looks little different from the above galaxy is only one third as far away at 0.93 billion light years.

PGC 169454 1.4 billion light years
PGC 139910 1.2 billion light years
PGC 41285 1.1 billion light years
PGC 169422 1.5 billion light years

The rest of the PGC galaxies have no red shift data that I was able to find.

Arp's image of the jet with the 200" scope is at:
http://nedwww.ipac.caltech.edu/level...ig_arp152.jpeg

This was a processing nightmare for me. I've been working on it for weeks now. Getting the core, galaxy and possible globulars to all show in one smooth image was difficult. I had to make three images, one for each feature and then layer them in so the seams didn't show. Thank goodness for all of Photoshop's layering options, I think I used most of them.

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Rick

Attached Images

	ARP152M87L4X10rgb2x10r3-8.jpg (144.2 KB, 24 views)
	ARP152M87L4X10rgb2x10r3crop2x.jpg (86.8 KB, 26 views)
	ARP152M82L4X10RGB2X10R-ID.jpg (107.0 KB, 15 views)

Hi Rick, You did Awesome in combineing all the data into one beautiful masterpiece. Very impressive image. Clear Skies my friend.

That's pretty hardcore!

I assume the spiel at the bottom is the detail of your photography. So that was taken with a 14" telescope? You must know what you're doing.

777 geek,

After over 50 years of doing this I hope I have some idea of what I'm doing.

Today's digital equipment has completely change the "rules" of astrophotography. When I was a kid they were just building the 200" Palomar telescope which cost only 6 million dollars in depression era dollars. When completed in 1949 it was 4 times larger in light collecting area than the next largest scope and was to answer "every" astronomical question thanks to its big eye. When I finished my 6" scope in 1954 I remember dreaming of what it must be like to use the 200" telescope. Things are very different today. Now for less than the cost of most of the pontoon boats seen on my lake you can take images that rival those of the 200" back in that era that so enthralled the public, and me, back then when published in magazines like Life and National Geographic. Thanks to today's technology I'm able to live that dream I had some 55 years ago and at a tiny fraction of the cost. Of course the big scopes now use the same technology so are again far ahead but as far as "pretty pictures" are concerned we are still pretty equal. I just need far more exposure time than they do.

The key today isn't so much in taking the image but in processing the data you do get. A computer screen can only reproduce a very limited brightness range that is divided into only 256 levels. A monitor has difficulty even reproducing all of these. So you have to process an image that may range in brightness from 8th to 21st magnitude, a range of about 160,000 times into those 256 levels. I've still got a lot to learn about that and about color balance of an image.

The bottom line just tells the telescope and that it was used at its native f/10 rather than use a compressor as is commonly done with such a long focal length scope, next is the exposures used, 4 luminosity images of 10 minutes each and two of similar duration for each of the three primary colors; red, green and blue so the image consists of 40 minutes of luminosity data (used for detail) and an hour of color data (colorizes the luminosity image). You could forgo the luminosity data and just use color data but that means far more exposure time. Since only 1/3rd the light gets through a color filter you need 3 times the exposure to go as deep as an unfiltered luminosity image so I'd need 2 hours per filter or a total of 6 hours to do what I do using a luminosity layer in only 100 minutes and achieve the same signal to noise ratio. During that extended time the atmosphere will tend to distort the image so the end result will often be worse due to all the time the atmosphere has to mess me up. Major observatories are usually located where seeing is far above average. I don't have that luxury. The next field is just the sensor used and lastly the mount the telescope is on. This is usually far more important than the telescope. Since you have to track the object across the sky and do so with extreme precision for 100 minutes in my case, longer with a smaller telescope, the quality of the mounting is of "paramount" importance. I fought average mounts into submission for decades, it was no fun. I was always wanting to do more than the mount was capable of doing. I finally had enough and got this mounting. Still my total cost is about that of a basic new car, less than my wife's Honda CRV. So I drive a pickup with 245,000 miles on it but have my observatory. We all have to have our priorities!

Rick

Edited thread name to Arp 152: The universe's largest roman candle?

__________________
Insanity: doing the same thing over and over again and expecting different results.
Albert Einstein

Thanks, my brain was in neutral when I typed the subject line originally. I was told by another moderator not long ago that changing this was impossible even for him. There is a way after all.

Rick

Thank you Mr J!
Most enchanting listening to you.

Thank you too for the Arps. Lovely Arpworks.

__________________
clear skies

If you want to make an apple pie from scratch, you must first create the universe. CARL SAGAN

Mak: Pass the pepperoni please.
Fazor: "Hail, Bautainia! We pledge our hearts to thee! Science and woo, some babbling too, and astron-oh-meee!"
slang: And it made ash out of yew and tree.