Title | The distribution and kinematics of H I in the active elliptical galaxy NGC 1052. |
Authors | van Gorkom, J. H.; Knapp, G. R.; Raimond, E.; Faber, S. M.; Gallagher, J. S. |
Bibcode | 1986AJ.....91..791V Search ADS ↗ |
Abstract | The H I distribution in the active elliptical galaxy NGC 1052 has been mapped at a resolution of 1 arcmin with the VLA. The H I structure is about three times the size of the optical galaxy and is roughly perpendicular to its major axis. The H I has a circular velocity of ̃ 200 km/s, roughly constant with radius; the mass of the galaxy is 1.5 × 1011 Msun at a radius of 16 kpc (D = 13.4 Mpc), and the mass to blue luminosity ratio at this radius is M /LB ̃ 15 Msun/Lsun. H I absorption is seen against the central radio continuum source, at both the systemic velocity and at redshifted velocities. The gas in NGC 1052, as in other ellipticals, has a rotation axis that is not aligned with the stellar rotation axis (the difference is 63°) and a mean specific angular momentum that is considerably larger than that of the stars. The H I distribution is unusually irregular. in the southwest region of the galaxy, the distribution shows what appears to be a tidal tail, suggesting that the H I may have been acquired about 109 years ago. The presence of dust associated with the H I and the distribution and kinematics of the H I are consistent with capture of gas from a gas-rich dwarf or spiral. in the inner regions of the galaxy (r <5 kpc) the H I velocity field shows evidence of noncircu1ar orbits and therefore possibly of a triaxial mass distribution for the galaxy. Alternatively the gas could be falling in toward the center. The redshifted absorption seen in this galaxy, and seen towards the nuclei of a few other early-type radio galaxies, suggests that the accretion of gas into the center might be a general phenomenon in radio galaxies. |
Objects | 9 Objects Search NED ↙ |