Atomic Gas in the Ring Galaxy Arp 143
November 4, 2003
A composite image of the optical light (green and yellow) and cold atomic hydrogen gas (blue) in the "Ring Galaxy" Arp 143 (a.k.a. NGC 2444/5). The atomic hydrogen observations, taken with the VLA in its C and D-array configurations, shows a suprising gaseous tidal tails reaching far to the north of this galaxy, to a total distance of 175 kpc or 570,000 light years in length (for Ho=75 km/s/Mpc). There was no hint of this tidal tail in previous optical images. Deeper optical imaging may show a hint of starlight associated with the tail, but it is mostly a gaseous structure. Notice gas also associated with the classical grand-design spiral galaxy to the right.
Topics: Barred spiral galaxies, Spiral galaxies, Local Group, NGC, Atlas of Peculiar Galaxies, Messier objects, Galaxy, Milky Way