Object name: NGC7448

Designation(s): NGC7448, ARP13, NGC7463, NGC7464, NGC7465, UGC12313,

Arp 013/NGC 7448 is in Arp's class of galaxies with detached segments. Since all of its spiral structure is composed of many detached pieces of arm structure I'm not sure which pieces or all of them he is referring too. Or is he referring to the large star clusters in the northwestern part of the galaxy that are about as bright as the core? His only comment is that this is a high surface brightness galaxy so that is of no help.

The galaxy is about 84 million light-years distant by redshift and is located in Pegasus just outside the southwest corner of the Great Square. It anchors what is known as the NGC 7448 group. I originally took this galaxy in late 2008 with it centered in the field. This missed all other members of the group. Conditions weren't all that good, especially for blue data. Also my processing back then wasn't all that great either, for color especially. This is a retake of it with Arp 13 moved to the very western edge of the field so I could pick up 4 more interesting members of the group on the eastern edge of my image. They are UGC 12313, NGC 7463, 4 and 5. All show signs of interaction, likely with each other. I've noted their redshift distance and NED classification on the annotated image. While the redshift distances vary between 70 and 91 million light-years they are all likely about the same actual distance from us.

UGC 12313 is a very low surface brightness galaxy that looks somewhat like a spiral with a core region but is classed as irregular which usually has no recognizable core. It has what appear to be plumes at both ends though the one to the northwest is most obvious. The trio of NGC 7463-5 is very interesting with all sorts of plumes. NGC 7465 appears the most interesting appearing nearly face on to us with two outer partial rings of stars whose centers don't match the location of the barred galaxy's core. This is a very unusual structure yet I found little on it in the literature. NGC 7463 is a more edge-on spiral with arms that appear to have been drawn outward by tidal interactions with others in the group. Caught in the middle (apparently) is NGC 7464. A highly distorted elliptical galaxy that is surprisingly blue for an elliptical. In fact, it is bluer than NGC 7463 which is about the normal blue for an Sb galaxy. I'd expect elliptical galaxies to be rather red as normally star formation is usually hidden from our view being isolated to the core region. That doesn't appear the case here.

NGC 7463 and 7465 were discovered by William Herschel on October 16, 1784. Neither are in either of the Herschel 400 observing programs. NGC 7464 was discovered by Heinrich d'Arrest on August 27, 1864.

NED has no other information on the field but for one quasar below this group at nearly 10 million light-years. I see a lot of interesting background galaxies but I can't find much on any of them other than the few NED includes are 2MASS galaxies and thus very bright in far IR radiation.

Arp's image of Arp 13:

14" LX200R @ f/10, L=4x10' RGB=2x10', STL-11000XM, Paramount ME

Related Designation(s):

1RXS J230200.8+155757, 1WGA J2302.0+1557, 2MASS J23000360+1558489, 2MASS J23000361+1558516, 2MASS J23015195+1558547, 2MASS J23015204+1558546, 2MASS J23015355+1558232, 2MASS J23015371+1558255, 2MASS J23020095+1557533, 2MASX J23000358+1558493, 2MASX J23015197+1558546, 2MASX J23015371+1558256, 2MASX J23020095+1557535, 2MASXi J2300035+155849, 2MASXi J2301519+155854, 2MASXi J2301537+155825, 2MASXi J2302009+155753, 2PBC J2302.1+1558, AKARI J2300039+155843, AKARI J2302009+155752, ARK 573, ARP 013, ARP13, CGCG 2257.6+1542, CGCG 2259.3+1542, CGCG 2259.3+1543, CGCG 2259.5+1542, CGCG 453-042, CGCG 453-048, CGCG 453-049, CGCG 453-050, CXO J230200.9+155753, CXO J230200.97+155753.2, HDCE 1227 NED001, HDCE 1227 NED003, HDCE 1227 NED004, HIPASS J2300+15, HOLM 802A, HOLM 802B, HOLM 802C, IRAS 22575+1542, IRAS 22595+1541, IRAS F22575+1542, IRAS F22594+1542, KUG 2257+157, KUG 2259+156, KUG 2259+157A, KUG 2259+157B, KUV 22576+1543, LCSB S2741O, LDCE 1553 NED001, LDCE 1553 NED003, LDCE 1553 NED004, LGG 469:[G93] 001, LGG 469:[G93] 003, LGG 469:[G93] 006, LGG 469:[G93] 007, LQAC 345+015 004, MCG +03-58-018, MCG +03-58-021, MCG +03-58-022, MCG +03-58-023, MCG +03-58-024, MRK 0313, NGC 7448, NGC 7463, NGC 7464, NGC 7465, NGC 7465:[L2011a] X0001, NGC 7465:[LB2005] X01, NGC7448, NGC7463, NGC7464, NGC7465, NSA 150440, NSA 150494, NSA 150497, NSA 150498, NSA 150499, NVSS J230003+155851, NVSS J230200+155751, PG 2259+156, PG 2259+157, PGC 070213, PGC 070285, PGC 070291, PGC 070292, PGC 070295, PRC D-42, RSCG 83:[WBJ2013] A, RSCG 83:[WBJ2013] B, RSCG 83:[WBJ2013] C, SDSS J230003.60+155848.8, UGC 12294, UGC 12313, UGC 12315, UGC 12316, UGC 12317, UGC12313, USGC U830 NED03, USGC U830 NED04, USGC U830 NED05, USGC U830 NED07, UZC J230003.7+155850, UZC J230151.9+155855, UZC J230153.6+155826, UZC J230200.9+155753, WBL 695-001, WBL 695-002, WBL 695-003, [HDL96] 453-005, [HDL96] 453-011, [HDL96] 453-012, [M98j] 253 NED01, [M98j] 253 NED03, [M98j] 253 NED04, [M98j] 253 NED05, [MHH96] J230200+155756, [RHM2006] SFGs 141, [TCW2007] 191, [VCV2001] J230201.0+155753, [VCV2006] J230201.0+155753, [WGB2006] 225918+15430_a, [WGB2006] 225918+15430_b, [WGB2006] 225918+15430_c,