NGC 520 from Hubble

Update 9/7/2021: This image has been chosen as and APOD by NASA! You can view their write-up here: https://apod.nasa.gov/apod/ap210907.html.

This galaxy is just so bizarre that I had to process it! NGC 520 is the product of a collision between two disc galaxies that started 300 million years ago. It exemplifies the middle stages of the merging process: the discs of the parent galaxies have merged together, but the nuclei have not yet coalesced. It features an odd-looking tail of stars and a prominent dust lane that runs diagonally across the centre of the image and obscures the galaxy.

Image:

Processing details:

Data was taken by Hubble’s Advanced Camera for Surveys (ACS) from the following proposal: https://archive.stsci.edu/proposal_search.php?mission=hst&id=9735

Red: hst_9735_11_acs_wfc_f814w
Green: hst_9735_11_acs_wfc_f555w
Blue: hst_9735_11_acs_wfc_f435w

Processing:

• Crop
• Histogram transformation to clip bad data
• Combine Channels
• Color calibration
• ArcsinH stretch for RGB
• Masked stretch and histogram transformation for L
• LRGB combination
• In photoshop, get rid of charge bleeds, hot pixels, and artifacts
• Curves transformation
• Multiscale processing using Curves, MMT, HDRMT, and Atrous wavelets transform
• Histogram transformation
• Curves transformation
• Saturation adjustment