Galaxies, an asterism and a gravitational lens

[wimvb]

Yesterday I reprocessed an image from november 2021. It features ngc 672, ic 1727, some smaller galaxies, and an asterism. With the new Xterminator tools, I was able to pull out more detail. Afterwards I researched the objects in the image, and found an article describing a gravitational lens which was in the field of view.

The galaxy tagged as J0150+2725 is the lensing galaxy. The galaxy itself is approximately 4.5 billion light years distant. It acts as a gravitational lens for one or several galaxies that are three times as far away. A study with the Hubble Telescope has shown that the lensed galaxy has a red shift of 1.08. The lensed galaxy is of course not visible in this image. Or is it? Some of the red fuzzy patches around J0150+2725 are indicated in the mentioned study. But it's not clear to me if these are in fact lensed galaxies.
https://iopscience.iop.org/article/10.3847/1538-4365/ab5f13/pdf
Near the top of the image is the faintest and most distant galaxy cluster I have ever captured. In the yellow circle is galaxy cluster RM J014914.9+273706.1. The galaxies in this cluster have a red shift of 0.506, which puts them at 6.8 billion light years distant. The light that was captured for this image, left those galaxies when what would become our sun, was still a cloud of hydrogen atoms, slowly growing denser and hotter.
There are several quasars in this image, I have only tagged the ones with a red shift of approximately 2 and higher. Several others with red shifts between 1.2 - 1.6 are strewn across the field of view.
J014947.9+271728 is a candidate subdwarf star. Subdwarf stars are hot, blue stars that are less luminous than main sequence blue stars. These stars are burning Helium.
"To end up on the EHB, stars have to lose almost their entire hydrogen envelopes in the red-giant phase, most likely via binary mass transfer. Consequently, hot subdwarfs have turned out to be important objects to study close binary interactions and their companions can be substellar objects such as brown dwarfs, all kinds of main sequence stars, white dwarfs, and maybe even neutron stars or black holes." 
https://www.aanda.org/articles/aa/full_html/2019/01/aa34236-18/aa34236-18.html
 

Here's the annotated version

 

Technical details:

145 x 4 minutes RGB exposures (580 minutes total), taken with my 190MN and ASI294MM

Processed in PixInsight.

Next season I'll revisit this area and collect more data, including H-alpha. i think that both the larger galaxies have H-alpha knots that would really make this image even more interesting.

Edited May 1, 2023 by wimvb

[Saganite]

Superb image, just beautiful.

  The tiniest Galaxy ( bottom right corner , I think ) to the ones in the foreground bring out, for me,   the bitter sweet  feelings for the immense Cosmos. 

[wimvb]

6 hours ago, Saganite said:

Superb image, just beautiful.

  The tiniest Galaxy ( bottom right corner , I think ) to the ones in the foreground bring out, for me,   the bitter sweet  feelings for the immense Cosmos. 

Thank you, Steve. That small galaxy isn't even catalogued, but guessing from its size in the image, and information on similar galaxies, I'd say that it's between 300 and 500 Mly distant. That is not as far away as the galaxy tagged as J0150+2725. That galaxy is more than 4 billion light years distant. Four billion years ago, the solar system was in its infancy.

The galaxies that are furthest away and still identifiable in my image, are near the top edge. A small galaxy cluster that is just visible as red diffuse patches is 6.8 billion light years distant. When the light that is recorded in the image left that cluster, what would eventually become the sun was still a cloud of hydrogen. The cloud slowly increased in density and temperature, until a star was born. Truly mind boggling.

Edited May 1, 2023 by wimvb

[wimvb]

I've had a closer look at the objects in this image, and found a few interesting facts. I edited the original post and added references