Detalles de publicación
PP 011049
Detection of Infalling Hydrogen in transfer between between the interacting galaxies NGC 5426 and NGC5427
1. IAC, (2) Dept. Astrofísica ULL (3) CSIC, (4) UNAM, México DF. (5) Lab. d'Astrophysique Toulouse-Tarbes. (6) CNRS, IRAP, Toulouse. (7) Dept. Astronomy. U.Stockholm, (8) Oscar Klein Centre, Stockholm., (9) Dept. Physique et Astronomie,U. Montreal. (10). Dept. Astronomy, U. Cape Town (11) UNAM, Ensenada,
(12).Dept. Fis. Teorica y del Cosmos, U. Granada., (13). Dept Física, Escuela Sup. Fis. Mat. IPN, UP Adolfo Lopez Mateos. México.
Using velocity tagging we have detected hydrogen from NGC 5426 falling onto its
interacting partner NGC 5427. Our observations, with the GHaFaS Fabry-Perot
spectrometer, produced maps of the two galaxies in Hα surface brightness and radial
velocity. We found emission with the range of velocities associated with NGC 5426
along lines of sight apparently emanating from NGC 5427, superposed on the
velocity map of the latter. After excluding instrumental effects we assign the
anomalous emission to gas pulled from NGC 5426 during its passage close to NGC
5427. Its distribution, more intense between the arms and just outside the disk of
NGC 5427, and weak, or absent, in the arms, suggests that the infalling gas is behind
the disk., ionized by Lyman continuum photons escaping from NGC 5427. Modeling
this, we estimate the distances of these gas clouds- behind the plane: a few hundred pc
to a few kpc. We also estimate the mass of the infalling (ionized plus neutral) gas,
finding an infall rate of 10 M per year, consistent with the high measured SFR across
the disk of NGC 5427 and with the detected circumnuclear galactic wind.
interacting partner NGC 5427. Our observations, with the GHaFaS Fabry-Perot
spectrometer, produced maps of the two galaxies in Hα surface brightness and radial
velocity. We found emission with the range of velocities associated with NGC 5426
along lines of sight apparently emanating from NGC 5427, superposed on the
velocity map of the latter. After excluding instrumental effects we assign the
anomalous emission to gas pulled from NGC 5426 during its passage close to NGC
5427. Its distribution, more intense between the arms and just outside the disk of
NGC 5427, and weak, or absent, in the arms, suggests that the infalling gas is behind
the disk., ionized by Lyman continuum photons escaping from NGC 5427. Modeling
this, we estimate the distances of these gas clouds- behind the plane: a few hundred pc
to a few kpc. We also estimate the mass of the infalling (ionized plus neutral) gas,
finding an infall rate of 10 M per year, consistent with the high measured SFR across
the disk of NGC 5427 and with the detected circumnuclear galactic wind.