Firstly, to fully appreciate the depth achieved in this image, make sure you turn up the brightness on your phone, or ideally view on a computer monitor in a dimly lit room and adjust/increase your screen brightness appropriately,
this grey scale can help. Please enjoy a surf around any of the Full Resolution versions linked to below.
Ultra Deep image of M83
This is an extremely deep image of the southern spiral galaxy M83 and immediate surrounds, in Hydra and is perhaps (?) even the deepest, as far as revealing extended diffuse features, that has ever been compiled of this galaxy, while also displaying the full dynamic range of the scene and in colour? The image shows a wealth of detail** across the galaxy disc and main spiral arms and both Halpha and OIII data have been included in the image to better reveal the extensive star forming regions across the galaxy. Generally considered an intermediate sized spiral, an extensive outer halo, that envelopes the galaxy out to over 24 arc min in diameter, has been revealed, this is approximately double the normally referenced apparent size of 12.5 X 10 arc min, for the galaxy. At the distance of M83, this apparent size equates to an actual diameter of over 110,000 light years. Not previously seen this clearly, subtle contrast enhancement applied to this halo has revealed it to be comprised of a number of very faint but distinctly separate, long spiral arms, that wrap around and envelope the galaxy. Also seen and first revealed by Malin and Hadley (1997) in deep amplified photographic plates, taken with the UK Schmidt Telescope at the Australian Optical Observatory, is a very faint outer stellar stream (bottom left), whose curve is closely concentric with and located somewhat distant from and north west of the galaxy.
**NB: No Blur Exterminator or other AI based sharpening was used on this data.
The data for this image was collected over six nights during April, May and June and on all but one of those nights, when the seeing bloated out for a couple of hours (not even good enough for RGB!), the seeing was most excellent, with the raw FWHM of the Lum frames, as measured in MaximDL, consistently ranging between 1.5" and 1.8" over the more than 27 hours of data collection, which is very helpful in preserving detail and acheive my goal of revealing some actual stellar resolution in the galaxy arms. I am convinced I need a finer image scale than 0.84"/pix, in order to take better advantage of such conditions...fingers crossed I can get some smaller pixels in the light path some day, for the good nights
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See the image on:
Astrobin
Pbase galleries
Flickr
This
high contrast stretch, reveals the full extent of the galaxy halo and confirms that the outer halo is likely also physically connected to the distant north west stellar stream.
Here is a link to an annotated version identifying the many peculiar star clusters and stellar nurseries found straying way out in the galaxy halo
Here is a composite of some of the many distant galaxies around M83
This paper by Barnes et al. provides some interesting insights into the structure and formation of M83 and the nature of the north west stellar stream.
Hope you enjoy
Mike