Messier 104 : Sombrero Galaxy Ultradeep imaging
Updated: Jun 20, 2021
Messier 104, a lenticular galaxy located 28 million light-years away in the constellation Virgo, now has a new chapter in its story — an extended halo of metal-rich stars with barely a sign of the expected metal-poor stars that have been observed in the halos of other galaxies. We captured this deep view from Insight observatory which host's 16" Dream Instrument with 16803 CCD FLI PL.
The Sombrero Galaxy occupies an area 8.7 X 3.5 arc minutes in apparent size, and its linear diameter is about 50,000 light years. The galaxy is inclined at an angle of only 7 degrees to our line of sight and appears edge-on. It is visible in binoculars and small telescopes, but only appears as a small patch of light. 4-inch telescopes may hint at the galaxy’s dark dust lane under exceptionally good conditions, but the dust lane usually requires a 10-inch or 12-inch telescope. The galaxy’s bulge and disk are visible in 8-inch and larger telescopes.
Messier 104 has an incredibly bright nucleus, an unusually large central bulge, and a conspicuous dark dust lane in its disk. The appearance of the galactic bulge and the dust lane that crosses in front of it have earned M104 the name Sombrero. The dust lane has the shape of a symmetrical ring around the bulge. The ring contains most of M104’s cold hydrogen gas and dust and is the primary site of starburst activity within M104.
The Sombrero Galaxy’s large bulge and supermassive black hole at its core make the galaxy a popular target for study.
The galaxy was previously believed to have a small, light halo, typical for a spiral, but observations with the Spitzer Space Telescope have revealed a considerably larger and more massive halo, commonly seen in giant elliptical galaxies. The Sombrero Galaxy’s vast halo may extend for 10,000 light years beyond the spiral structure.
Interesting feature of Messier 104
If Messier 104 is photographed long enough then it would reveal a faint halo and tidal stream, These Streams were discovered by Dr. David Malin who is also considered the father of Modern Astrophotography.
What is a Tidal Stream? A stellar stream is an association of stars orbiting a galaxy that was once a globular cluster or dwarf galaxy that has now been torn apart and stretched out along its orbit by tidal forces. There are several galaxies which show such phenomenon like the hamburger galaxy , NGC 5907 .
In the 1990s, a research group led by John Kormendy demonstrated that a supermassive black hole is present within the Sombrero Galaxy. Using spectroscopy data from both the CFHT and the Hubble Space Telescope, the group showed that the speed of revolution of the stars within the center of the galaxy could not be maintained unless a mass 1 billion times that of the Sun, 109M☉, is present in the center. This is among the most massive black holes measured in any nearby galaxy.
Processing Messier 104
Messier m104 is not an easy galaxy to process as there is not much subject area to work with and in adding the core is quite bright making it hard for fellow imagers to capture a nice view of this galaxy now here I made natural high dynamic range image which is combination of several images in to one which means that I made several versions of the galaxy specially with Luminance and combined into one to give a natural view of the subject. Majority of the images of internet do not show these streams or if they do, then the images are poorly over-stretched ultimately destroying the beauty of the region, however its all about choice how one wants his images to look like but to make a final natural looking image we have to work hard.
Post-Processing was mainly done in Pixinsight and Photoshop CC
RGB were combined in Pixinsight using Channel combination.
Photometric Color calibration was used with G2V so we can get a good balance of colors.
After the non-linear data was color calibrated, I went on stretching it using masked stretch as it helps us in preserving the core detail, however our Luminance data's core was bit saturated as we went for 300sec 1x1 subs, FLI 16803 has a great dynamic range but still it could not manage the brightness of core but I was able to manage it.
I stretched the RGB image and saved it.
I had to deal with some gradients in Luminance as the galaxy was quite close to horizon while imaging so Dynamic Background Extraction took care of it I kept tolerance level to 0.700.
Stretching
After clearing out the gradients I made a super luminance version of Messier 104 as it would help me in pulling the extremely faint structure, I removed all the stars carefully then my own techniques of blending in Photoshop I made a HDR which showed the Streams and the background levels was balanced to.
Sharpening
After I created a super stretched version it lacked the overall look of the messier m104 so I made an extremely sharp version of Messier 104 which was made very carefully and then I blended into the super stretched image.
I kept on sharpening carefully until I felt its adding the noise and then I would revert back and apply it to the final image.
RGB+L
My Luminance was ready my color version was ready so now I had to combine both into one, I used luminosity mode In Photoshop to combine the luminance into RGB as I have much more control during the process. Since the luminance data is superior in majority of the cases we apply a bit of saturation to the image as its would make it look washed out.
My LRGB version was prepared and was looking quite nice but still lacked the colors sharpness, so I went on with my color techniques to bring out some nice colors in the image. Rest of the tweaks were made in PI and finally back in PS to make a good final adjust.
Technical Information ATEO 16" F3.7 dream scope Astrograph Newtonian Telescope
Paramount MEII
FLI PL 16803 CCD
Badder LRGB
Luminance: 56 images at 300 sec (4.6 hours) 1x1 binning
RGB: 20 for each filter at 300 sec (1.6 hours each filter, 4.8 hours total RGB) Binning 1x1. This image is Awarded Astrobin Image of the day My instagram : @mr_deepsky
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