HST Observing Program Description:

The HST component of GOALS involves a Cycle 14 program (Evans et al., Program #10592) consisting of ACS/WFC imaging of the complete set of 88 LIRGs and ULIRGs with LIR > 1011.4 L in the IRAS Revised Bright Galaxy Sample (RBGS: i.e., 60 μm flux density > 5.24 Jy). This sample is ideal not only in its completeness and sample size, but also in the proximity and brightness of the galaxies. The superb sensitivity, resolution, and field of view of ACS/WFC on HST enables a unique opportunity to study the detailed structure of galaxies that sample all stages of the merger process. Images obtained in the F439W and F814W filters (B and I-band) are being analyzed. This HST survey bridges the wavelength gap between our Spitzer imaging survey (covering seven bands in the 3.6 – 160 μm range) and IRS spectroscopy, and GALEX UV imaging of these galaxies, but resolves complexes of star clusters and multiple nuclei at a resolution well beyond the capabilities of Spitzer and GALEX.

Our primary goals are to examine, as a function of both luminosity and merger state:

  • The evidence at optical wavelengths of star formation and AGN activity and the manner in which instabilities (bars and bridges) in the galaxies may funnel material to these active regions;
  • The relationship between star formation and AGN activity;
  • The structural properties (AGN, bulge, and disk components) and fundamental parameters (effective radius and surface brightness) of LIRGs and ULIRGs and their similarity with putative evolutionary byproducts (elliptical, S0 and classical AGN host galaxies);
  • Perform a comprehensive analysis of super star clusters;
  • Search for correspondence between the properties of the galaxies at optical wavelengths; with properties measured in the infrared with Spitzer, in the ultraviolet with GALEX, and in X-rays with Chandra.

A tabulated target list of the HST imaging program is provided here.

Click here for the HST image gallery.
The high-resolution poster can be downloaded here (~60MB): poster_HST.pdf