Mon. Not. R. Astron. Soc., 407, 1674-1688 (2010/September-3)
NGC765 - a disturbed HI giant.
PORTAS A.M., BRINKS E., FILHO M.E., USERO A., DYKE E.M. and BELLES P.-E.
Abstract (from CDS):
We present Hi spectral line and radio-continuum Very Large Array (VLA) data of the galaxy NGC765, complemented by optical and Chandra X-ray maps. NGC765 has the largest Hi-to-optical ratio known to date of any spiral galaxy and one of the largest known Hi discs in absolute size with a diameter of 240 kpc measured at a surface density of 2x1019 atom/cm2. We derive a total Hi mass of, a dynamical mass of Mdyn∼ 5.1x1011M☉ and an Hi mass-to-luminosity ratio of MHI/LB= 1.6, making it the nearest and largest `crouching giant'. Optical images reveal evidence of a central bar with tightly wound low surface brightness spiral arms extending from it. Radio-continuum (L1.4GHz= 1.3x1021 W/Hz) and X-ray (LX~ 1.7x1040 erg/s) emission is found to coincide with the optical core of the galaxy, compatible with nuclear activity powered by a low-luminosity active galactic nucleus. We may be dealing with a galaxy that has retained in its current morphology traces of its formation history. In fact, it may still be undergoing some accretion, as evidenced by the presence of Hi clumps the size (<10 kpc) and mass (108-109M☉) of small (dIrr) galaxies in the outskirts of its Hi disc and by the presence of two similarly sized companions.
© 2010 The Authors. Journal compilation © 2010 RAS
galaxies: evolution - galaxies: individual: NGC765 - galaxies: individual: UGC1453 - galaxies: interactions - galaxies: kinematics and dynamics - galaxies: structure
Table 3: [PBF2010] A (Nos A-D). Table B1: [PBF2010] N (Nos 1-8). Table C1: [PBF2010] XN (Nos X1-X6).
NGC 765a is AGC 113836 in Simbad. [GH83] 024 is LGG 41 in Garcia 1993.
View the reference in ADS
To bookmark this query, right click on this link: simbad:2010MNRAS.407.1674P and select 'bookmark this link' or equivalent in the popup menu