Open AccessPossible formation scenarios for the giant H i envelope around the NGC 4490/4485 system
Author(s) -
Clemens M. S.,
Alexander P.,
Green D. A.
Publication year - 1998
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1998.01510.x
Subject(s) - physics , astrophysics , galaxy , astronomy , supernova , galactic plane , outflow , meteorology
We present observations of H i in the nearby interacting galaxies NGC 4490 and 4485 made with the VLA in both C and D arrays. The galaxies are embedded in an extensive envelope of neutral hydrogen which is elongated in a direction approximately perpendicular to the plane of NGC 4490, with an extent of about 56 kpc. We argue that this distribution of neutral hydrogen can best be explained by a galactic‐scale bipolar outflow of H i driven by supernovae in NGC 4490. The flow from the disc appears to be reasonably well collimated and has probably persisted for approximately 6 × 10 8 yr. The implications for galaxy evolution when such mass loss occurs are briefly discussed.