| NGC 7609 | |
|---|---|
 Hubble Space Telescope image of NGC 7609, the brightest galaxy located right | |
| Observation data | |
| Constellation | Pegasus |
| Right ascension | 23h 19m 30.05s |
| Declination | +09d 30m 29.6s |
| Redshift | 0.039624 |
| Heliocentric radial velocity | 11,879km/s |
| Distance | 554Mly (170Mpc) |
| Group orcluster | Hickson 95 |
| Apparent magnitude (V) | 15.23 |
| Characteristics | |
| Type | E3, E |
| Size | 207,000ly |
| Notable features | Interacting galaxy |
| Other designations | |
| 2MASX J23193006+0930295,PGC 71076,HCG 095A,SDSS J231930.07+093029.8, VV 20a,CGCG 406-065,MCG +01-59-047,ARP 150, NSA 151130, WISEA J231930.04+093029.9, V1CG 625 NED01 | |
NGC 7609 or known asArp 150 andHCG 95A, is a largeelliptical galaxy located inPegasus.[1][2] Itsspeed relative to thecosmic microwave background is 11,879 km/s, which corresponds the galaxy to be located 554 millionlight-years away fromEarth (169.7Mpc).[3] NGC 7609 was discovered on October 5, 1864, byAlbert Marth[4] and included inHalton Arp's,Atlas of Peculiar Galaxies in galaxies that produces jets.[5]
With asurface brightness ofapparent magnitude 14.59, NGC 7609 is classified as alow surface brightness galaxy (LSB).[6] LSB galaxies are diffuse galaxies with surface brightness that is one less magnitude, of thenight sky.
ASDSS survey image and from theHubble Space Telescope, showed that NGC 7609 isinteracting with nearby galaxy, PGC 71077 (HCG 95C) whosespiral arms is currently being absorbed by the larger entity.[7] A double-nuclei is present in HCG 95C, which is considered a merger remanent of twodisk galaxies.[7] Twotidal tails[8] are also found in NGC 7609 and HCG 95C region, which seems to connect together,[9] and there is a linear bridge between two galaxies indicating nuclear activity is taking place in HCG 95C.[10] From the study written from Vilchez & Iglesias-Paramo in 1998, Hα emission is detected in thenuclei of both galaxies and also the larger tidal tails (the eastern tail).[11]
A long slit spectra of NGC 7609 shows, it exhibits red-shiftedH-alpha +[N II] and [S II]emission lines that is indicative to aLINER-type AGN (Active Galactic Nucleus).[10]
From the spatial profiles, this indicates non-nuclearstarburst activity triggered bytidal forces while nuclear spectrum indicates nonthermal activity. From the further IUE observations of HCG 95C, it presents a featurelesscontinuum with transient outburst captured in one observation, showing galactic emission ofred-shifted N v (1240 A) and C IV (1550 A). This result depicts HCG 95C is in the early stages ofmerging with NGC 7609.[10]
According to another study, it is suggested that adwarf galaxy might have been created at the tip of the northern tidal tails.[12]
NGC 7609 is a member ofHickson Compact Group 95.[13][14] There are total of fourgalaxies in the group, in which the members are PGC 71074, PGC 71077 and PGC 71080.[15][16] Of all the four galaxies, PGC 71080 (HCG 95B) is a foreground galaxy, as its line-of-sightvelocity of 8000km/s significantly differs from the velocity of the other members per published by Hickson et al.[17]
A study mentions there is a detection of 89 candidateultra-diffuse galaxies (UDGs), around NGC 7609 and HCG 95, in which one is linked with. It is a gas-rich galaxy with H i mass 1.1 x 10M⊙, detected byVery Large Array, and has astellar mass of M 1.8 x 10M⊙.[18] This indicates that UDGs partially overlap with population of nearlydark galaxies found in deep H I surveys. The results show high abundance of blue UDGs in the HCG 95 field is favored by the poorgalaxy cluster environment residing in H I-richlarge-scale structures.[18]
Onesupernova has been observed in NGC 7609. SN 1973M (type unknown, mag. 19) was discovered byCharles Kowal on 8 June 1973.[19][20]