Galaxy Merger Fractions in Two Clusters at z similar to 2 Using the Hubble Space Telescope Academic Article uri icon


  • 2019. The American Astronomical Society. All rights reserved.. We measure the fraction of galaxy-galaxy mergers in two clusters at z ,F ,F2 using imaging and grism observations from the Hubble Space Telescope. The two galaxy cluster candidates were originally identified as overdensities of objects using deep mid-infrared imaging and observations from the Spitzer Space Telescope, and were subsequently followed up with HST/WFC3 imaging and grism observations. We identify galaxy-galaxy merger candidates using high-resolution imaging with the WFC3 in the F105W, F125W, and F160W bands. Coarse redshifts for the same objects are obtained with grism observations in G102 for the z ,F ,F1.6 cluster (IRC0222A) and G141 for the z ,F ,F2 cluster (IRC0222B). Using visual classifications as well as a variety of selection techniques, we measure merger fractions of in IRC0222A and in IRC0222B. In comparison, we measure a merger fraction of for field galaxies at z ,F ,F2. Our study indicates that the galaxy-galaxy merger fraction in clusters at z ,F ,F2 is enhanced compared to the field population, but note that more cluster measurements at this epoch are needed to confirm our findings.

published proceedings


altmetric score

  • 7.58

author list (cited authors)

  • Watson, C., Tran, K., Tomczak, A., Alcorn, L., Salazar, I. V., Gupta, A., ... Willmer, C.

citation count

  • 15

complete list of authors

  • Watson, Courtney||Tran, Kim-Vy||Tomczak, Adam||Alcorn, Leo||Salazar, Irene V||Gupta, Anshu||Momcheva, Ivelina||Papovich, Casey||van Dokkum, Pieter||Brammer, Gabriel||Lotz, Jennifer||Willmer, Christopher NA

publication date

  • March 2019