The
morphological classification of NGC 1068 in the
De Vaucouleurs system is (R)SA(rs)b,[5] where the '(R)' indicates an outer ring-like structure, 'SA' denotes a non-barred spiral, '(rs)' means a transitional inner ring/spiral structure, and 'b' says the spiral arms are moderately wound.[9] Ann
et al. (2015) gave it a class of SAa,[10] suggesting tightly wound arms. However,
infrared images of the inner part of the galaxy reveal a prominent bar not seen in visual light,[11] and for this reason it is now considered a barred spiral.[12]
Messier 77 is an
active galaxy with an
active galactic nucleus (AGN), which is obscured from view by astronomical dust at visible wavelengths. The diameter of the molecular disk and hot plasma associated with the obscuring material was first measured at radio wavelengths by the
VLBA and
VLA. The hot dust around the nucleus was subsequently measured in the mid-infrared by the
MIDI instrument at the
VLTI. It is the brightest[13] and one of the closest and best-studied[12] type 2
Seyfert galaxies,[3] forming a prototype of this class.[12]
M77 Type II Supernova, November 2018
X-ray source 1H 0244+001 in Cetus has been identified as Messier 77.[14] Only one
supernova has been detected in Messier 77. The supernova, named SN 2018ivc, was discovered on 24 November 2018 by the DLT40 Survey. It is a
type II supernova, and at discovery it was 15th magnitude and brightening.[15]
It has a radio jet consisting of a northeast and a southwest region, caused by interactions with the interstellar medium.[16]
In February 2022 the European Southern Observatory found a cloud of cosmic dust at the centre of Messier 77 hiding a
supermassive black hole.[17]
In November 2022, the
IceCube collaboration announced the detection of a
neutrino source emitted by the active galactic nucleus of Messier 77.[18][19] It is the second detection by IceCube after
TXS 0506+056, and only the fourth known source including
SN1987A and
solar neutrinos.
NGC 1106 Another galaxy with an active galactic nucleus.
References
^
abSkrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; Beichman, Charles A.; Capps, Richard W.; Chester, Thomas; Elias, Jonathan H.; Huchra, John P.; Liebert, James W.; Lonsdale, Carol J.; Monet, David G.; Price, Stephan; Seitzer, Patrick; Jarrett, Thomas H.; Kirkpatrick, J. Davy; Gizis, John E.; Howard, Elizabeth V.; Evans, Tracey E.; Fowler, John W.; Fullmer, Linda; Hurt, Robert L.; Light, Robert M.; Kopan, Eugene L.; Marsh, Kenneth A.; McCallon, Howard L.; Tam, Robert; Van Dyk, Schuyler D.; Wheelock, Sherry L. (1 February 2006).
"The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183.
Bibcode:
2006AJ....131.1163S.
doi:10.1086/498708.
ISSN0004-6256.
S2CID18913331.
^Thronson, Harley A. Jr.; et al. (1 August 1989), "Near-infrared image of NGC 1068 - Bar-driven star formation and the circumnuclear composition", Astrophysical Journal, Part 1, 343: 158–168,
Bibcode:
1989ApJ...343..158T,
doi:
10.1086/167693.
^
abcAlexander, Tal; Lutz, Dieter; Sturm, Eckhard; Genzel, Reinhard; Sternberg, Amiel; Netzer, Hagai (June 2000), "Infrared Spectroscopy of NGC 1068: Probing the Obscured Ionizing AGN Continuum", The Astrophysical Journal, 536 (2): 710–717,
arXiv:astro-ph/0002107,
Bibcode:
2000ApJ...536..710A,
doi:
10.1086/308973,
S2CID15617708.