TYC 2839-969-1 , the SIMBAD biblio

2007AJ....134.1019O - Astron. J., 134, 1019-1036 (2007/September-0)

The cold gaseous halo of NGC 891.


Abstract (from CDS):

We present H I observations of the edge-on galaxy NGC 891. These are among the deepest ever performed on an external galaxy. They reveal a huge gaseous halo, much more extended than seen previously and containing almost 30% of the H I. This H I halo shows structures on various scales. On one side, there is a filament extending (in projection) up to 22 kpc vertically from the disk. Small (M_HI_≳106 M) halo clouds, some with forbidden (apparently counterrotating) velocities, are also detected. The overall kinematics of the halo gas is characterized by differential rotation lagging with respect to that of the disk. The lag, more pronounced at small radii, increases with height from the plane. There is evidence that a significant fraction of the halo is due to a galactic fountain. Accretion from intergalactic space may also play a role in building up the halo and providing the low angular momentum material needed to account for the observed rotation lag. The long H I filament and the counterrotating clouds may be direct evidence of such accretion.

Abstract Copyright:

Journal keyword(s): Galaxies: Halos - Galaxies: Individual: NGC Number: NGC 891 - Galaxies: ISM - Galaxies: Kinematics and Dynamics - Galaxies: Structure

CDS comments: Fig. 1 : star A is 2MASS J02225405+4218401, star B is 2MASS J02222169+4223472.

Simbad objects: 17

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