Hubble Space Telescope multi-color ACS mosaic of M51,
the Whirlpool Galaxy

Home | Download data | README file | AAS poster and full text | Browse page

In January 2005, the Hubble Heritage Team obtained a large 4-color mosaic image of the Whirlpool Galaxy NGC 5194 (M51), and its companion NGC 5195, with the Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST). See HST observing program 10452 (PI: Steven V. W. Beckwith) for details:

A six-pointing ACS WFC mosaic of the galaxy pair M51 was obtained in four filters: B, V, I, and H-alpha.

To the right is the six-pointing ACS mosaic overlay on the DSS image of M51 from the Digitized Sky Survey.

The resulting color composite image was released to the community on April 25, 2005 to celebrate Hubble's 15th anniversary. Since the M51 mosaics produced by the Hubble Heritage Team represent a significant investment of expert processing beyond the standard archival products, these drizzle-combined FITS have been released simultaneously as a High-Level Science Product via the Multimission Archive at Space Telescope (MAST).

We provide a list of downloadable FITS files and some associated preview GIF images. We also provide a browse page with another set of browse by "pointing" (mosaic tile). This browse option is not directly related to the FITS files. For a few weeks, we provide the _flt HST pipeline products for each filter: F435W; F555W; F658N; F814W.

A very complete text-only README file has been provided which describes key aspects of the observing program, the standard pipeline processing, and the post-pipeline combination of these images into complete mosaics. The details of the data processing will be also be presented as a poster at the AAS Meeting in Minneapolis, May 30-31, 2005. See the displayed poster, and the full text handout (essentially an updated and illustrated version of the README file). Please reference this poster paper (Mutchler et al., 2005, AAS Vol 37 No 2) if you utilize these mosaics for scientific analysis.

Data may be downloaded via your web browser from the list of FITS files mentioned above or via anonymous ftp. FTP to archive.stsci.edu logging on as anonymous then cd /pub/hlsp/m51. The FITS files are contained in the directory "version1". The preview gif files in the directory "previews". The HST pipeline products are grouped in directories by filter (f435w, f555w, f658n, f814w).