The Small Magellanic Cloud (SMC) is an irregular dwarf galaxy, which is located ~200000 light years away. The SMC is thought to have once been a barred spiral galaxy but it has been disrupted and shaped by interactions with it’s neighbours, the Large Magellanic Cloud and the Milky Way galaxy. These interactions result in intense ram pressures and gravitational tidal shocks which have stripped and re-distributed material from the SMC forming an extended envelope of ionised gas. This ionised gas is located in an extended halo but also in a number of large, faint ionised structures. One structure is the SMC tail and the Magellanic bridge, which connects the SMC to the LMC, and this was formed from an interaction which occurred ~200 million years ago. The other main structure is the Magellanic stream, a giant cloud of gas which extends over 100 degrees from the SMC and LMC towards the Milky Way. When starting the project, my aim was to try to capture a deep image of the SMC and to try to show some of this extended halo.
I produced a heavily stretched starless Ha false colour image highlighting the extended emission halo structures. You can see the SMC tail/bridge extending to the top right, and faint filaments towards the bottom of the frame which appear to extend towards the Magellanic stream. At the top left, there are two faint emission objects (circled white on the Astrobin image) in the outer halo, and I believe this is the first image to clearly show these faint objects.
To get an idea of the extent of the ionised halo, I aligned and overlayed my Ha falsecolour map with the Ha emission map detected by the Wisconsin Ha Mapper (WHAM) as published by Smart et al, 2019. WHAM is a 0.6m scope with a Fabry-Perot spectrometer designed to investigate the warm interstellar medium. It’s design allows it to record a spectrum from a 1 degree area of sky, allowing WHAM to detect extremely faint emission albeit at a low spatial resolution. In this image you can see the WHAM Ha emission extending even further to the right into the Magellanic bridge and downwards into the Magellanic stream.
In my image you can also just discern some of the faint outer stellar halo of the SMC, which appears to give the SMC a slightly unfamiliar shape. Low surface brightness stellar halos and stellar streams are predicted in hierarchical galaxy formation models as a result of a succession of merger events with lower mass systems. To check this halo, I created an outline of the outer SMC halo from a stellar density map of the SMC made with Gaia DR2 sources as published in Mart ́ınez-Delgado 2019. I have overlaid this halo outline on a similarly aligned crop of my image, and you can see the stellar density halo outline closely matches that in my image.
Yes that's yet another crackerjack image from you Matthew!
I've been privy to some discussions on AB from pixel peepers about the star shapes in your previous images, but these appear to have been resolved now.
Yey again a brilliant reference image of the region for us all to enjoy, well done!
Cool (and very deep) presentation of this area Mathew, very nice work
Love that setup
Mike
Thanks Mike! Hope your new obs is progressing nicely, looks to be an amazing spot 😀
Quote:
Originally Posted by Andy01
Yes that's yet another crackerjack image from you Matthew!
I've been privy to some discussions on AB from pixel peepers about the star shapes in your previous images, but these appear to have been resolved now.
Yey again a brilliant reference image of the region for us all to enjoy, well done!
Thanks Andy! Hopefully the pixel peeps will be happier, and can appreciate the forest as well as the trees 😂
Quote:
Originally Posted by Dave882
Mate this is absolutely stunning …and a lot of research in your presentation there to chew through too. Thanks so much for sharing!!
Cheers David, glad you liked it and thanks for the feedback 👍
One thing - I'm always curious, but to me it seems just a little wide for a 400mm lens on a full-frame (36x24mm) sensor. Is it a 2 panel mosaic, or was a reducer used, or 300mm 2.8, or ...?
Yep, this is stunning. Amazing presentation. Art and science, you're a master. Nice one, Matthew!
Wow, thanks Adam!
Quote:
Originally Posted by gregbradley
A terrific image Matthew. Great colour depth.
Greg.
Thanks Greg, appreciate it 😀
Quote:
Originally Posted by Camelopardalis
Beautiful shot Mathew
Thanks Dunk!
Quote:
Originally Posted by JA
That's a superb image Mat - Well done
One thing - I'm always curious, but to me it seems just a little wide for a 400mm lens on a full-frame (36x24mm) sensor. Is it a 2 panel mosaic, or was a reducer used, or 300mm 2.8, or binning, or ...?
Best
JA
Cheers JA 👍 You are quite correct-this is a 3 panel mosaic. I had originally planned 2 panels but decided it looked a bit unbalanced without 47 Tuc being visible so added the extra panel. There is some cropping given the rotation between panels. I have to say processing the mosaic was a real challenge and I ended up having success with the excellent Mosaic by Coordinates and Photometric Mosaic scripts in Pixinsight.
Cheers JA �� You are quite correct-this is a 3 panel mosaic.
That's good - I'm not going nuts.
May I ask which version Nikkor 400/2.8 you use - is it the MF-AIS, AF, AF-I, AF-S, AF-S FL, or...? I have the old school AIS version, yet to be set to task.
May I ask which version Nikkor 400/2.8 you use - is it the MF-AIS, AF, AF-I, AF-S, AF-S FL, or...? I have the old school AIS version, yet to be set to task.
Best
JA
I have the Nikon 400mm f/2.8E FL version 👍
Cheers, Mat
Thanks for another great image Matt and an excellent write up. I did also note the switch to the 400mm lens and it looks like you have this performing well.
great framing, very nice integration. i usually find it hard to get excited about ultra widefield images, but something twitched with this one. great depth and contrast with ngc 346 and eso 51-20 at this fl.
Thanks for another great image Matt and an excellent write up. I did also note the switch to the 400mm lens and it looks like you have this performing well.
Thanks Rodney! I wanted to get a bit more resolution than with the 200mm and so switched to the 400mm. So far it’s going well, still have a few minor tweaks and some optimising to do. Cheers, Mat
Quote:
Originally Posted by AG Hybrid
Brilliant. If you submit it - your image has got to be in a shout for APOD.
Thanks Adrian, not sure about an APOD but glad you liked it 👍
Quote:
Originally Posted by Addos
great framing, very nice integration. i usually find it hard to get excited about ultra widefield images, but something twitched with this one. great depth and contrast with ngc 346 and eso 51-20 at this fl.
nice
Thanks Adam! I think the 400mm fl does suit this, I had to look up eso 51-20 which does look like a nice small cluster😀 Cheers, Mat