NGC 383 gx chain in Pisces
Posted 12 November 2013 - 04:52 PM
Posted 13 November 2013 - 01:51 AM
Here is my drawing of this area with a 13 inch Newtonian at 100X, so the field of view is larger, but at this lower power I did not pick out the fainter galaxies. Lots of fun.
Posted 16 November 2013 - 02:35 PM
The Arp 331 group and nearby NGC 507 group nytecam showcased Nov 9. These two groups are a minor part of what Adventures in Deep Space http://astronomy-mal...ce/agcintro.htm capsules as, ‘One of the largest known structures in the universe is the Perseus - Pisces Supercluster. This huge filament of galaxy clusters extends from the Perseus Cluster (Abell 426) through Abell 347 and Abell 262 in Andromeda into the NGC 507 and NGC 383 galaxy groups in northern Pisces. Even at a distance of 250 million light years, this chain of galaxy clusters extends more than 40 degrees across the winter sky.’
It’s noteworthy that the linear chain we discern in nytecam and Steve’s images is a real gravitational feature. It lies perpendicular to the plane of the filamentary ridge from which the entire Perseus-Pisces Supercluster has formed. See PDF page 5 (p.36) of the 1994 paper above for an informative map of the properties of the chain. Similar linear-weighted alignments occur in the next-door NGC 507 group from IC 1689 to NGC 512, and from CGC 710 to 712 in the further-off Abell 262 group. Michael Vlasov’s ‘Deep Sky Hunter’ http://www.deepskywa...psky-atlas.html atlas (#36) shows at these alignments in charts we can print out for use at the eyepiece. These seemingly contrary perpendicular features originate when large galaxy clusters form in filamentary clumps from cold gas infalling along the plane of an enormous proto-galactic wall. The Perseus-Pisces Supercluster is one such wall, and is one of the two largest in the nearby universe. Cold gas falls in pretty much perpendicular to the gravitational well of the wall itself. That induces chains of galaxy formation in filaments. In larger galaxy clusters like Abell 262 these are smoothed into round shapes as the clusters stabilize gravitationally. Small-mass clusters like NGC 383 don’t have enough gravity to ‘virialize’ themselves—meaning their total outward kinetic energy is less than the total energy acting on them from outside—so they retain the chain-like shape of their primordial formation.
And to think, all this congealed immensity came out of nytecam’s two recent images and Steve Coe’s helpful eyepiece sketch. Kudos to all.
Posted 17 November 2013 - 01:58 AM