by Chris Peterson » Mon Sep 05, 2022 5:21 pm
VictorBorun wrote: ↑Mon Sep 05, 2022 5:12 pm
Chris Peterson wrote: ↑Mon Sep 05, 2022 5:05 pm
Sa Ji Tario wrote: ↑Mon Sep 05, 2022 3:28 pm
I counted 8, there is one to the left of the letter "C" of CSA
I spent about 10 minutes and got 25 definite or probable galaxies.
_
CarinaCliffs_Webb_2000_gal.jpg
Do they count as
dust-piercing infrared light has enabled it to capture fascinating details in the dust, hundreds of previously hidden stars, and even some galaxies far in the distance
?
Or just the one in the middle does?
Well, every background object in this image is shining through dust, it's just a question of how thick the dust is (in optical light, even the area on top is nearly opaque). It's tricky finding galaxies in the dust because the dust is colored similarly and contains fine structure, both of which serve to obscure them to casual examination. The way to identify them is to push a single channel through a tool like SExtractor, which is very good at separating stars from galaxies given their different profiles (stars being fit to a Moffat distribution, but not galaxies). I'm sure such an approach would pull quite a few more galaxies out from the dustier areas.
[quote=VictorBorun post_id=325617 time=1662397933 user_id=145500]
[quote="Chris Peterson" post_id=325614 time=1662397507 user_id=117706]
[quote="Sa Ji Tario" post_id=325612 time=1662391687]
I counted 8, there is one to the left of the letter "C" of CSA
[/quote]
I spent about 10 minutes and got 25 definite or probable galaxies.
_
CarinaCliffs_Webb_2000_gal.jpg
[/quote]
Do they count as
[i]dust-piercing infrared light has enabled it to capture fascinating details in the dust, hundreds of previously hidden stars, and even some galaxies far in the distance[/i]
?
Or just the one in the middle does?
[/quote]
Well, every background object in this image is shining through dust, it's just a question of how thick the dust is (in optical light, even the area on top is nearly opaque). It's tricky finding galaxies in the dust because the dust is colored similarly and contains fine structure, both of which serve to obscure them to casual examination. The way to identify them is to push a single channel through a tool like SExtractor, which is very good at separating stars from galaxies given their different profiles (stars being fit to a Moffat distribution, but not galaxies). I'm sure such an approach would pull quite a few more galaxies out from the dustier areas.