NGC 1275 consists of two galaxies, a central
type-cD galaxy in the Perseus Cluster, and a so-called high velocity system (HVS) which lies in front of it. The HVS is moving at 3000 km/s[4] towards the dominant system, and is believed to be merging with the Perseus Cluster. The HVS is not affecting the cD galaxy as it lies at least 200 thousand light years from it.[5] However
tidal interactions are disrupting it and the
ram pressure produced by its interaction with the
intracluster medium of Perseus is stripping its gas as well as producing large amounts of star formation within it[6]
The central cluster galaxy contains a massive network of
spectral line emitting filaments,[7] which apparently are being dragged out by rising bubbles of
relativisticplasma generated by the central
active galactic nucleus.[8] Long gaseous filaments made up of threads of gas stretch out beyond the galaxy, into the multimillion-degree, X-ray–emitting gas that fills the cluster. The amount of gas contained in a typical thread is approximately one million times the mass of the
Sun. They are only 200 light-years wide, are often very straight, and extend for up to 20,000 light-years.[9]
The existence of the filaments poses a problem. As they are much cooler than the surrounding intergalactic cloud, it is unclear how they have existed for such a long time, or why they have not warmed, dissipated or collapsed to form stars.[10][11] One possibility is that weak magnetic fields (about one-ten-thousandth the strength of Earth's field) exert enough force on the
ions within the threads to keep them together.[10][11]
The presence of an active nucleus demonstrates that a
supermassive black hole is present in NGC 1275's center. The black hole is surrounded by a rotating disk of molecular gas.[14] High-resolution observations of the rotation of this disk obtained using
adaptive optics at the
Gemini North telescope indicate a central mass of approximately 800 million
Solar masses, including both the mass of the black hole and of the inner core of the gas disk.[15]
Two
supernovae have been observed in NGC 1275: SN 1968A (type unknown, mag. 15.5),[16] and SN 2005mz (
type Ia, mag. 18.2).[17]
^Ho, Luis C.; Filippenko, Alex V.; Sargent, Wallace L. W. (October 1997). "A Search for "Dwarf" Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies". Astrophysical Journal Supplement. 112 (2): 315–390.
arXiv:astro-ph/9704107.
Bibcode:
1997ApJS..112..315H.
doi:
10.1086/313041.
S2CID17086638.
^Minkowski R., 1957, in IAU Symp 4, Radio astronomy, p107
^Gallagher, John S. III; Lee, M.; Canning, R.; Fabian, A.; O'Connell, R. W.; Sanders, J.; Zweibel, E. (2010). "Dusty Gas and New Stars: Disruption of the High Velocity Intruder Galaxy Falling Towards NGC 1275". Bulletin of the American Astronomical Society. 42: 552.
Bibcode:
2010AAS...21536308G.
^Lim, Jeremy; Ao, Yi Ping; Dinh-v-Trung, Dinh-V-Trung (2008). "Radially Inflowing Molecular Gas in NGC 1275 Deposited by an X-Ray Cooling Flow in the Perseus Cluster". The Astrophysical Journal. 672 (1): 252–265.
arXiv:0712.2979.
Bibcode:
2008ApJ...672..252L.
doi:
10.1086/523664.
S2CID119249662.
^O'Connell, Robert (2007). "Star Formation in the Perseus Cluster Cooling Flow". HST Proposal ID #11207. Cycle 16: 11207.
Bibcode:
2007hst..prop11207O.