Examining the Growth of Black Holes in the Protocluster Environment at z = 3.1: The HST WFC3 IR View of Galaxies in the SSA22 Protocluster
Abstract
The well-studied z ~ 3 protocluster in the SSA22 field has been shown to exhibit an elevated fraction of activity by Active Galactic Nuclei (AGN) compared to fields at similar redshifts. This activity may be fueled by an increased merger rate, either past or present, among protocluster members. High resolution near-infrared (NIR) imaging can be used to characterize the distribution of stellar mass among the protocluster members, and may detect the disturbed galaxy morphologies associated with mergers. We have obtained new Hubble WFC3 F160W (~1.6 µm) observations of the SSA22 field centered on previously-identified protocluster AGN (Lehmer et al. 2009). In this work we use GALFIT and Gini-M20 analysis of galaxies detected in new and archival F160W images to characterize the NIR morphologies of SSA22 protocluster galaxies. We compare the extracted morphologies to galaxies elsewhere in the SSA22 field and to a sample of Lyman-Break Galaxies (LBGs) in HDF-N via a GALFIT catalog produced by van der Wel et al. (2012). We find no statistically significant difference in the NIR morphologies of protocluster galaxies and their field counterparts. To characterize the distribution of stellar masses in the protocluster, we fit SEDs to protocluster LBGs using broadband UV-NIR photometry. We present a new, publicly available catalog for the SSA22 field, containing our extracted morphologies as well as archival photometry and spectroscopic redshifts, where available. Finally, we discuss possible sources of the observed enhancement of AGN activity in the context of our results.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23537119M