| NGC 1266 | |
|---|---|
 Hubble image of NGC 1266 | |
| Observation data (J2000epoch) | |
| Constellation | Eridanus |
| Right ascension | 03h 16m 00.7s[1] |
| Declination | −02° 25′ 38″[1] |
| Redshift | 0.007238 ± 0.000017[2] |
| Heliocentric radial velocity | 2170 ± 5 km s−1[2] |
| Distance | 29.9Mpc[2] |
| Characteristics | |
| Type | S0[2] |
| Half-light radius (physical) | 2.96kpc |
| Half-light radius (apparent) | 20.4"[2] |
| Notable features | AGN, molecular outflow, suppressedSFR |
| Other designations | |
| PGC 12131 | |
NGC 1266 is alenticular galaxy in the constellationEridanus. Although not currentlystarbursting, it has undergone a period of intense star formation in the recent past, ceasing only ≈500 Myr ago.[3] The galaxy is host to an obscuredactive galactic nucleus.[4]
A massive molecular outflow, with 2.4 × 107 M of hydrogen, is present from the nucleus of the galaxy,[4] at a rate of 110 M yr−1.[5] Less than 2% of the gas (2 M yr−1) is escaping the galaxy. Momentum coupling to the jet of the AGN is likely driving the outflow.[5]
The current observedstar-formation rate (SFR) of ~0.87 M yr−1 is significantly lower than expected for a galaxy of its properties, suppressed by a factor of 50 to 150. Authors have put forth several hypotheses to explain these observations. The most likely scenario is that the AGN-driven molecular outflow is injecting turbulence into the nuclear regions, preventinggravitational collapse ofmolecular clouds.[5] NGC 1266 is the first known intermediate-mass galaxy to show AGN-driven suppression of star formation.
Two hypotheses exist to explain NGC 1266's nuclear activity and excessivefar-IR emission. Either a heavily obscured ultracompact starburst is present in the nuclear regions, or a powerful buried AGN is present, beyond what has been inferred from other observations. Neither scenario is without problems. The black hole at the center of the galaxy is likely growing according to theM–sigma relation, and eventually the outflow will result in the removal of the majority of the gas from the nucleus.[5]
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