by Ann » Sun Jan 12, 2020 5:44 pm
TheOtherBruce wrote: ↑Sun Jan 12, 2020 4:32 pm
Leon1949Green wrote: ↑Sat Jan 11, 2020 3:12 pm
I have a similar question to ptahhotep: for so many galaxies to be in this line of sight, are they in another cluster? and/or along one of the strings even of the Local Group, or at least the Virgo Supercluster?
I was thinking the picture is "zoomed in" enough for us to start seeing far background objects, which are pretty much everywhere in every direction. Look at the various Hubble Deep Field pictures; those are of apparently empty patches of sky, in between local stars and not-so-distant galaxies.
Take a look at the galaxies and judge for yourself.
Are the galaxies of similar sizes? Are their colors similar, i.e., do they seem to have the same amount of "redshift reddening" from the expansion of the Universe? Are their "textures" similar?
There are two galaxies very close to each other (apparently touching) (at 10 o'clock) which are of similar sizes, but very different colors. One is whitish and one is orange. Yes, they could be actual neighbours, and one could simply be so full of star formation that its intrinsic color is quite different from its orange neighbour. Or one could just just by chance be very much more dust-reddened than the other one. But I wouldn't bet on it. It is possible that the orange one is much farther into the background than the white one and that it is interacting with the orange galaxy to its lower right, not with the white one.
Also take a look at the very fluffy galaxy at 1 o'clock. It is so fluffy that it looks more like a flattened globular cluster than a galaxy, at least its outer parts. My guess is that this is a small, relatively low-mass galaxy (or just possibly a globular cluster) that is much closer than almost all the other background galaxies.
But you should be able to detect many galaxies that seem to belong together because they are of similar sizes and colors, and also they are close together int he sky. My guess is that these galaxies are actual neighbours in space.
Ann
[quote=TheOtherBruce post_id=298725 time=1578846727 user_id=144738]
[quote=Leon1949Green post_id=298699 time=1578755526]
I have a similar question to ptahhotep: for so many galaxies to be in this line of sight, are they in another cluster? and/or along one of the strings even of the Local Group, or at least the Virgo Supercluster?
[/quote]
I was thinking the picture is "zoomed in" enough for us to start seeing far background objects, which are pretty much everywhere in every direction. Look at the various Hubble Deep Field pictures; those are of apparently empty patches of sky, in between local stars and not-so-distant galaxies.
[/quote]
Take a look at the galaxies and judge for yourself.
Are the galaxies of similar sizes? Are their colors similar, i.e., do they seem to have the same amount of "redshift reddening" from the expansion of the Universe? Are their "textures" similar?
There are two galaxies very close to each other (apparently touching) (at 10 o'clock) which are of similar sizes, but very different colors. One is whitish and one is orange. Yes, they could be actual neighbours, and one could simply be so full of star formation that its intrinsic color is quite different from its orange neighbour. Or one could just just by chance be very much more dust-reddened than the other one. But I wouldn't bet on it. It is possible that the orange one is much farther into the background than the white one and that it is interacting with the orange galaxy to its lower right, not with the white one.
Also take a look at the very fluffy galaxy at 1 o'clock. It is so fluffy that it looks more like a flattened globular cluster than a galaxy, at least its outer parts. My guess is that this is a small, relatively low-mass galaxy (or just possibly a globular cluster) that is much closer than almost all the other background galaxies.
But you should be able to detect many galaxies that seem to belong together because they are of similar sizes and colors, and also they are close together int he sky. My guess is that these galaxies are actual neighbours in space.
Ann