The image was created from Hubble data from proposals 10842: K. Cook (Lawrence Livermore National Laboratory), M. Gregg (University of California, Davis), L. Macri (National Optical Astronomy Observatories, AURA), J. Mould (University of Melbourne), P. Stetson (Dominion Astrophysical Observatory), and D. Welch (McMaster University); and 11956: K. Noll, Z. Levay, L. Frattare, C. Christian, F. Hamilton, and H. Bond (Hubble Heritage Team/STScI).
F450W (B), F606W (V), F673N (redshifted H-alpha), and F814W (I)
The image is a composite of separate exposures made by the ACS and WFPC2 instruments on the Hubble Space Telescope. Four filters were used to sample broad and narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
F673N (redshifted H-alpha) + F814W (I)