Spiral Galaxy NGC 5792 with Distant Background Quasars (updated)

[SkyViking]

Hi All,

I actually only took this image as a fill-in during some early evenings while waiting for another target to rise. However, this galaxy turned to be surprisingly photogenic and the background is littered with distant galaxies and an incredible 14 quasars! From my location this galaxy now disappears behind a hill very early in the evening, so I'll have to return next year for more data because it definitely deserves it. In the meantime here is what I got so far.

Large image (75% scale, 1MB): http://www.pbase.com/rolfolsen/image/144749889/original
Large image with 14 quasars marked (75% scale, 1MB): http://upload.pbase.com/rolfolsen/image/144749892/original

Image details:
Date: 17 June, 6th 7th 8th and 10th July 2012
Exposure: LRGB: 310:30:30:22.5m, total 6hrs 32.5mins @ -30C
Telescope: 10" Serrurier Truss Newtonian f/5
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

Here is a stretched view of the galaxy alone to illistrate what it might look like from above. It bears some resemblance to NGC 1365 in Fornax, but also contains what looks like an inner ring structure which is possibly caused by the two spiral arms being wound twice around the core:
http://www.pbase.com/rolfolsen/image/144781667/original

About the image:
NGC 5792 is a barred galaxy about 83 million light-years away in the constellation Libra. The bright red star at the lower edge of the galaxy is a red dwarf in our own Milky Way. This is in fact the most common type of star in the universe. The galaxy itself is fairly dim with an overall magnitude of 12.1. Since it is relatively large in size (6'.8 x 1'.7) the surface brightness is also low. The spiral arms that originate from the centre appears to almost form a continuous outer ring around the galaxy. This structure appears similar to that of NGC 1365 in Fornax, but is seen close to edge-on here. In the distant background behind NGC 5792 a wealth of faint galaxies dot the area and even 14 quasars lie within this narrow field of view.

Hope you enjoy. Personally I was pleasantly surprised by this galaxy. Comments and critique welcome as always.

Regards,
Rolf

[RickS]

Nice image and an intriguing little galaxy, Rolf! What focal length are you imaging at?

Cheers,
Rick.

[jsmoraes]

Very impressive image and well identified the quasars, since they look like stars.

[alocky]

As usual, a great image, but made even more interesting by the research that you've done on the object. Is that an unusually large number of quasars in the field of view, or is it typical of images that deep?
regards,
Andrew.

[gregbradley]

What a beautiful shot!

Spectacular Rolf!

I haven't seen an image of NGC5792 before.

Greg.

[Stevec35]

Excellent work Rolf!

Cheers

Steve

[iceman]

That's a beautiful galaxy, well done Rolf!

[allan gould]

Rolf, excellent data and image which is made more interesting by the identification of the quasars. Really well done.
Allan

[strongmanmike]

Excellent Rolf :thumbsup:

The galaxy NGC 5792 sure could be NGC 1365 simply lying over on its side more huh?

Your stars look better, did you tweak something?

Mike

[Paul Haese]

Very nice work Rolf. Lovely detail and very smooth.

[atalas]

Love the ring structure!nice work.

[Ross G]

A great galaxy photo Rolf.

The level of detail is amazing.

Ross.

[SkyViking]

Thanks for the comments everyone, I have updated the annotated image to include redshifts for the quasars that I could find data for.
I have also made a stretched image of NGC5792 itself to see what it might look like if we were able to see it from above: http://www.pbase.com/rolfolsen/image/144781667/original


Thank you Rick, it's an f/5, I have updated the image details now :)


Thanks very much Jorge. I used SIMBAD to find them.


Thank you Andrew, I was thinking that it might be a bit unusual to have that many quasars in such a narrow FOV. I recall from when I was looking for globulars around M104 (http://www.iceinspace.com.au/forum/showthread.php?t=92183) that there weren't a single quasar in sight, so they are definitely not evenly distributed at least.


Thanks a lot Greg, yeah it's not one that is often imaged to say the least. I could hardly find any info on it at all.


Thank you Steve :)


Thanks Mike, yeah I just had to give it a bit more time when I got the first frames and saw how nice this galaxy looked.


Thanks very much Allan, I'm glad you liked it.


Thank you Mike, I made this little image to show how it might look from above: http://www.iceinspace.com.au/forum/showthread.php?t=92183

Re the stars, I adjusted the collimation a bit, as you'll notice I have chopped a bit off the left and right edges in the image, it's about 75% of full frame. My flats are slightly off now because I played with the collimation, so it didn't look too good near the extreme edges. I have a new set of flats ready for the next image though :)


Thanks very much Paul. I didn't push the data so much this time, so yes the noise is kept in check.


Thank you Louie, it's an interesting galaxy for sure.


Thank you Ross, I'm glad you enjoyed it :)

[multiweb]

Terrific work again Rolf. Great read too. :thumbsup:

[stevous67]

Rolf, the results from your unique scope are excellent. This is simple beautiful. This is the scale I love the most.

Steve

[Rex]

Beautiful shot Rolf, and great information too.