akarsh
July 12th, 2021, 06:23 AM
Abell 2063
RA (J2000): 15:23:02
Dec (J2000): +08:38:22
Redshift (z): 0.035
I recently learned of this incredible galaxy cluster in Serpens Caput from Steve Gottlieb. Sometimes considered to be a member of the Hercules Supercluster (which usually includes Abell 2147, 2151 and 2152) [1], the estimated light-travel time to this object is about 460 Mly. The brightest galaxy in the cluster (BCG) is designated MCG +02-39-020, and the interesting fact about this cluster is that the BCG is not at the gravitational center of the cluster [1,3], suggesting a recent merger [3].
Several references list both IC 1116 and NGC 5920 as members of the cluster (e.g. [2] which lists the latter as a member of "ACO2063B"), in which case they would be the next in brightness. Other references [3] only conclude that the cluster Abell 2063 is interacting with the NGC 5920 group, also known as MKW 3s. I am not clear from my skimming of the papers, whether this interaction with MKW3s is the recent merger that has been hypothesized to explain the offset of the BCG from the gravitational center.
This is really a sprawling cluster! If one includes the NGC 5920 group, it spans over a degree in diameter. Here is a color DSS image to show the major galaxies and regions of the cluster, where the white square box is 1° x 1° in size for scale:
4384
(Image is not north up)
I studied the MCG +02-39-020 part of this cluster during my last observing session at "Shot Rock Vista", a site at about 7600 feet (2300m) elevation in the Sierra Nevada mountains of eastern California, formerly frequented by Alvin Huey! The skies there are somewhat light polluted, especially in the west and north-east, but still dark enough for such observations. Besides I enjoyed some good seeing, limited largely by wind currents and the astigmatism in my mirror support. I spent about 1 hour 15 minutes on this region, using a 6mm Delos on my 18" f/4.5 to observe this cluster (350x). Below is an annotated POSSII image where I've put a star on every galaxy I've logged. I managed to spot 22 galaxies (counting an unresolved pair once) within this region. The one marked with a '?' may have not met the "three flashes to log" criterion because I thought it was a star.
4385
(This image is north up)
I missed both the region around IC 1116 (which is ~20' away from the BCG) and the NGC 5920 group, but I'm sure someone else here has done a more comprehensive survey of this cluster. I wonder what is the total number of galaxies one can see in this cluster if one exhaustively searched it with large aperture. I'm sure there are at least 5--6 more within the reach of an 18".
As always,
give it a go and let us know!
[1] https://doi.org/10.1017/S1743921304001061
[2] https://arxiv.org/pdf/0903.2360.pdf
[3] http://adsabs.harvard.edu/pdf/1999AcA....49..403K
RA (J2000): 15:23:02
Dec (J2000): +08:38:22
Redshift (z): 0.035
I recently learned of this incredible galaxy cluster in Serpens Caput from Steve Gottlieb. Sometimes considered to be a member of the Hercules Supercluster (which usually includes Abell 2147, 2151 and 2152) [1], the estimated light-travel time to this object is about 460 Mly. The brightest galaxy in the cluster (BCG) is designated MCG +02-39-020, and the interesting fact about this cluster is that the BCG is not at the gravitational center of the cluster [1,3], suggesting a recent merger [3].
Several references list both IC 1116 and NGC 5920 as members of the cluster (e.g. [2] which lists the latter as a member of "ACO2063B"), in which case they would be the next in brightness. Other references [3] only conclude that the cluster Abell 2063 is interacting with the NGC 5920 group, also known as MKW 3s. I am not clear from my skimming of the papers, whether this interaction with MKW3s is the recent merger that has been hypothesized to explain the offset of the BCG from the gravitational center.
This is really a sprawling cluster! If one includes the NGC 5920 group, it spans over a degree in diameter. Here is a color DSS image to show the major galaxies and regions of the cluster, where the white square box is 1° x 1° in size for scale:
4384
(Image is not north up)
I studied the MCG +02-39-020 part of this cluster during my last observing session at "Shot Rock Vista", a site at about 7600 feet (2300m) elevation in the Sierra Nevada mountains of eastern California, formerly frequented by Alvin Huey! The skies there are somewhat light polluted, especially in the west and north-east, but still dark enough for such observations. Besides I enjoyed some good seeing, limited largely by wind currents and the astigmatism in my mirror support. I spent about 1 hour 15 minutes on this region, using a 6mm Delos on my 18" f/4.5 to observe this cluster (350x). Below is an annotated POSSII image where I've put a star on every galaxy I've logged. I managed to spot 22 galaxies (counting an unresolved pair once) within this region. The one marked with a '?' may have not met the "three flashes to log" criterion because I thought it was a star.
4385
(This image is north up)
I missed both the region around IC 1116 (which is ~20' away from the BCG) and the NGC 5920 group, but I'm sure someone else here has done a more comprehensive survey of this cluster. I wonder what is the total number of galaxies one can see in this cluster if one exhaustively searched it with large aperture. I'm sure there are at least 5--6 more within the reach of an 18".
As always,
give it a go and let us know!
[1] https://doi.org/10.1017/S1743921304001061
[2] https://arxiv.org/pdf/0903.2360.pdf
[3] http://adsabs.harvard.edu/pdf/1999AcA....49..403K