Photo Agency - Astronomy - Space - Nature
> Hickson Compact Group 87
Hickson Compact Group 87
author: Nasa/Hubble heritage team/Novapix
reference: a-amg02-00200
Image Size 300 DPI: 12 * 12 cm
Group of interacting galaxies located at about 400 million light-years. The largest galaxy member (HCG 87a), which is actually disk-shaped, but tilted so that we see it nearly edge-on and its elliptically shaped nearest neighbor (87b) have active galactic nuclei which are believed to harbor black holes that are consuming gas. A third group member, the nearby spiral galaxy 87c, may be undergoing a burst of active star formation. These three galaxies are so close to each other that gravitational forces disrupt their structure and alter their evolution.Â
From the analysis of its spectra, the small spiral near the center of the group could either be a fourth member or perhaps an unrelated background object. The HST image was made by combining images taken in four different color filters in order to create a three-color picture. Regions of active star formation are blue (hot stars) and also pinkish if hot hydrogen gas is present. The complex dark bands across the large edge-on disk galaxy are due to interstellar dust silhouetted against the galaxy's background starlight. A faint tidal bridge of stars can be seen between the edge-on and elliptical galaxies.
From the analysis of its spectra, the small spiral near the center of the group could either be a fourth member or perhaps an unrelated background object. The HST image was made by combining images taken in four different color filters in order to create a three-color picture. Regions of active star formation are blue (hot stars) and also pinkish if hot hydrogen gas is present. The complex dark bands across the large edge-on disk galaxy are due to interstellar dust silhouetted against the galaxy's background starlight. A faint tidal bridge of stars can be seen between the edge-on and elliptical galaxies.
Contact : Stéphane Aubin +33-(0)9-51-26-53-76
© Novapix - All rights reserved