The galaxies in this image — also known as NGC 4038 and NGC 4039 — are locked in a deadly embrace. Once normal, sedate spiral galaxies like the Milky Way, the pair have spent the past few hundred million years sparring with one another. This clash is so violent that stars have been ripped from their host galaxies to form a streaming arc between the two. In wide-field images of the pair the reason for their name becomes clear — far-flung stars and streamers of gas stretch out into space, creating long tidal tails reminiscent of antennae.
This new image of the Antennae Galaxies shows obvious signs of chaos. Clouds of gas are seen in bright pink and red, surrounding the bright flashes of blue star-forming regions — some of which are partially obscured by dark patches of dust. The rate of star formation is so high that the Antennae Galaxies are said to be in a state of starburst, a period in which all of the gas within the galaxies is being used to form stars. This cannot last forever and neither can the separate galaxies; eventually the nuclei will coalesce, and the galaxies will begin their retirement together as one large elliptical galaxy.
Image:
Details:
All data was taken by Hubble’s Advanced Camera for Surveys from the following proposal: https://archive.stsci.edu/proposal_search.php?mission=hst&id=10188.
Red: hst_10188_10_acs_wfc_f814w, hst_10188_10_acs_wfc_f658n
Green: hst_10188_10_acs_wfc_f550m
Blue: hst_10188_10_acs_wfc_f435w, hst_10188_10_acs_wfc_f658nProcessing:
- Subtract broadband from narrowband to just get emission
- integrate broadband to create lum
- Combine and color calibrate broadband
- add Ha to lum and broadband
- stretch lum and broadband
- LRGB combination
- photoshop to remove artifacts
- Multiscale processing using MMT and curves
- Curves transformation
- exponential transformation