Studying the physical properties of tidal features – I. Extracting morphological substructure in CANDELS observations and VELA simulations

作者：Kameswara Bharadwaj Mantha, Daniel H. McIntosh, Cody Ciaschi, Rubyet Evan, Henry C. Ferguson, Logan B. Fries, Yicheng Guo, Anton M. Koekemoer, Luther Landry, Elizabeth J. McGrath, Raymond C. Simons, Gregory F. Snyder, Scott Thompson, Eric F Bell, Daniel Ceverino, Nimish P. Hathi, Camilla Pacifici, Joel R. Primack, Marc Rafelski, Vicente Rodríguez-Gómez · 发表于：Monthly Notices of the Royal Astronomical Society · 年份：2019 · DOI：10.1093/mnras/stz872 · 被引用次数：21 · 研究领域：Galaxies: Formation, Evolution, Phenomena、Advanced Vision and Imaging、Adaptive optics and wavefront sensing

Abstract The role of major mergers in galaxy evolution remains a key open question. Existing empirical merger identification methods use non-parametric and subjective visual classifications that can pose systematic challenges to constraining merger histories. As a first step towards overcoming these challenges, we develop and share publicly a new python-based software tool that identifies and extracts the flux-wise and area-wise significant contiguous regions from the model-subtracted residual images produced by popular parametric light-profile fitting tools (e.g. galfit). Using Hubble Space Telescope (HST) H-band single-Sérsic residual images of 17 CANDELS galaxies, we demonstrate the tools ability to measure the surface brightness and improve the qualitative identification of a variety of common residual features (disc structures, spiral substructures, plausible tidal features, and strong gravitational arcs). We test our method on synthetic HST observations of a z ∼ 1.5 major merger from the VELA hydrodynamic simulations. We extract H-band residual features corresponding to the birth, growth, and fading of tidal features during different stages and viewing orientations at CANDELS depths and resolution. We find that the extracted features at shallow depths have noisy visual appearance and are susceptible to viewing angle effects. For a VELA z ∼ 3 major merger, we find that James Webb Space Telescope NIRCam observations can probe high-redshift tidal features with considerable...