11h39m01.721s, −-37° 44′ 18.60″| NGC 3783 | |
|---|---|
Hubble Space Telescope image of NGC 3793
| |
| Observation data (J2000 epoch) | |
| Constellation | Centaurus |
| Right ascension | 11h39m 01.721s[1] |
| Declination | –37° 44′ 18.60″[1] |
| Redshift | 0.008506 ± 0.000100[2] |
| Heliocentric radial velocity | +2,817[3] km/s |
| Distance | 135.7 Mly (41.60[4] Mpc) |
| Grouporcluster | NGC 3783 group |
| Apparent magnitude (V) | 13.43 |
| Characteristics | |
| Type | SBa[5] |
| Apparent size (V) | 1′.9 × 1′.7[5] |
| Notable features | Seyfert 1 |
| Other designations | |
| MCG -06-26-004, PGC 36101[6] | |
NGC 3783 is a barred spiral galaxy located about 135[4] million light years away in the constellation Centaurus.[7] It is inclined by an angle of 23° to the line of sight from the Earth along a position angle of about 163°. The morphological classification of SBa[5] indicates a bar structure across the center (B) and tightly-wound spiral arms (a).[8] Although not shown by this classification, observers note the galaxy has a luminous inner ring surrounding the bar structure. The bright compact nucleus is active and categorized as a Seyfert 1 type. This nucleus is a strong source of X-ray emission and undergoes variations in emission across the electromagnetic spectrum.[5]
The source of the activity in this galaxy is a rapidly rotating supermassive black hole, which is located at the core and is surrounded by an accretion disk of dust.[9] The estimated mass of this black hole, from reverberation mapping, is about 2.8 million times the mass of the Sun.[10] Interferometric observations yield an inner radius of 0.52 ± 0.16 ly (0.16 ± 0.05 pc) for the orbiting torus of dust.[11]
This is a member of a loose association of 47 galaxies known as the NGC 3783 group. Located at a mean distance of 117 million light-years (36 Mpc), the group is centered at coordinates α = 11h37m12s, δ = –37° 30′ 57.6″: equivalent to about 870×10^3 ly (267 kpc) from NGC 3783. The NGC 3783 group has a mean velocity of 2,903 ± 26 km/s with respect to the Sun and a velocity dispersion of 190 ± 24 km/s. The diffuse X-ray emission of the group is roughly centered on the galaxy NGC 3783.[12] The NGC 3783 group is located in the Hydra-Antlia region of the Hydra-Centurus Supercluster.[13][14]
