H i Streamers around M82: Tidally Disrupted Outer Gas Disk
Abstract
Our new VLA observations of M82 reveals a triangular central concentration of neutral atomic gas (1.9 x 10^8^ M_sun_) and several ~>10 kpc long tidal streamers originating from M82 itself. The coincidence of the beginning of the tidal streamer with the flaring of the optical disk as well as the smooth continuation of the disk velocity field into the H I streamer strongly suggest the tidal disruption of the disk of M82, contrary to the widely proposed scenario of tidal stripping and gas accretion from its neighbor M81. The velocity characteristics of H I within M82 are that of disk rotation as seen in CO. The gas kinematics appear complex because of large velocity dispersions that may be due to a tidally induced bar potential and the interaction between the disk gas and the nuclear wind. Closer to the nucleus, the H I features are associated with both optical filaments and dust lanes, and it is suggested that these H I clouds are the sites of reflection and scattering of the light originating from the nuclear region. The extinction characteristics of the dust associated with the H I gas are similar to the Galactic dust and argue against an intergalactic origin for this H I gas.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1993
- DOI:
- Bibcode:
- 1993ApJ...411L..17Y
- Keywords:
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- Interstellar Gas;
- Irregular Galaxies;
- Starburst Galaxies;
- Galactic Nuclei;
- Galactic Rotation;
- Very Large Array (Vla);
- Astrophysics;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M81;
- GALAXIES: INDIVIDUAL MESSIER NUMBER: M82;
- GALAXIES: INTERACTIONS;
- GALAXIES: IRREGULAR;
- GALAXIES: SPIRAL;
- GALAXIES: STARBURST