Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994aj....108..844m&link_type=abstract
The Astronomical Journal, vol. 108, no. 3, p. 844-850
Astronomy and Astrophysics
Astronomy
27
Dwarf Galaxies, Elliptical Galaxies, Galactic Nuclei, Galactic Structure, H I Regions, Interacting Galaxies, Radio Astronomy, Color, Data Processing, Image Reconstruction, Imaging Techniques, Interstellar Matter, Star Formation, Tables (Data), X Rays
Scientific paper
We present new U, B, R, and H I imagery of the Virgo Cluster giant elliptical galaxy NGC 4472 and its interacting dwarf companion galaxy UGC 7636. Using a composite image reconstruction technique, we show that a trail of debris approx. 5 arcmin in length and approx. 1 arcmin in width (30x6 kpc for a Virgo cluster distance of 20 Mpc) is projected northward from the dwarf galaxy. A cloud of H I is projected along the northwest edge of the debris between the dwarf and gE. The dwarf's nuclear morphology is irregular and bow-shaped on what appears to be its leading edge. Apart from a number of isolated blue regions, most of of the trailing debris is similar in color to the dwarf's nucleus. Only a modest enhancement of star formation appears to have been induced by the interaction. Although separated by 15 kpc, the H I and stellar morphologies are remarkably similar. The stars and H I appear to have been tidally distorted in situ, prior to the cloud's removal by ram pressure. If the H I has maintained its shape by magnetic support, a magnetic field strength an order of magnitude larger than the galaxy's is required. Ram pressure deceleration due to the cloud's motion through NGC 4472's x-ray-emitting interstellar medium should be sufficient for the cloud to become gravitationally bound to NGC 4472. The H I cloud is not self-gravitating and may fragment and be destroyed in the interaction. UGC 7636 will probably be disrupted by NGC 4472's strong tidal forces; the stellar debris will disperse into the Virgo cluster or become bound to NGC 4472's halo on eccentric orbits. The debris captured in the collision will have a negligible impact on NGC 4472's stellar and gaseous content. On the other hand, if similar interactions are common in giant elliptical galaxies, they could alter or deplete surrounding dwarf galaxy populations, fuel bursts of nuclear activity, and perhaps provide a source of magnetic energy to their interstellar media.
Henning Patricia A.
Junor William
McNamara Brian R.
Sancisi Renzo
No associations
LandOfFree
A violent interaction between the dwarf galaxy UGC 7636 and the giant elliptical galaxy NGC 4472 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A violent interaction between the dwarf galaxy UGC 7636 and the giant elliptical galaxy NGC 4472, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A violent interaction between the dwarf galaxy UGC 7636 and the giant elliptical galaxy NGC 4472 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1787338