Studying the Physical Properties of Tidal Features I. Extracting Morphological Substructure in CANDELS Observations and VELA Simulations

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 which 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 tool's ability to measure the surface brightness and improve the qualitative identification of a variety of common residual features (disk structures, spiral substructures, plausible tidal features, and strong gravitational arcs). We test our method on synthetic $HST$ observations of a $z\sim 1.5$ 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 $z\sim 3$ major merger, we find that James Webb Space Telescope NIRCam observations can probe high-redshift tidal features with considerable advantage over existing $HST$ capabilities. Further quantitative analysis of plausible tidal features extracted with our new software hold promise for the robust identification of hallmark merger signatures and corresponding improvements to merger rate constraints.

18 pages, 11 Figures, and accepted for publication in MNRAS. The data products discussed in this paper along with the software are publicly available at https://github.com/AgentM-GEG/residual_feature_extraction

References in corpus (26)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• 3D-HST+CANDELS: The Evolution of the Galaxy Size-Mass Distribution since $z=3$
• Compaction and Quenching of High-z Galaxies in Cosmological Simulations: Blue and Red Nuggets
• The role of stellar feedback in the formation of galaxies
• Sunrise: Polychromatic Dust Radiative Transfer in Arbitrary Geometries
• Stellar masses from the CANDELS survey: the GOODS-South and UDS fields
• The Redshift Evolution of Wet, Dry, and Mixed Galaxy Mergers from Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey
• The Structures of Distant Galaxies I: Galaxy Structures and the Merger Rate to z~3 in the Hubble Ultra-Deep Field
• A calibration of the relation between the abundance of close galaxy pairs and the rate of galaxy mergers
• The Structures of Distant Galaxies - III: The Merger History of over 20,000 Massive Galaxies at z < 1.2
• Ongoing Assembly of Massive Galaxies by Major Merging in Large Groups and Clusters from the SDSS
• GALAPAGOS: From Pixels to Parameters
• Galaxy And Mass Assembly (GAMA): Galaxy close-pairs, mergers, and the future fate of stellar mass
• From Tidal Dwarf Galaxies to Satellite Galaxies
• High-redshift major mergers weakly enhance star formation
• A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at $z<3.5$
• Massive Close Pairs Measure Rapid Galaxy Assembly in Mergers at High Redshift
• An automatic taxonomy of galaxy morphology using unsupervised machine learning
• Major Merging History in CANDELS. I. Evolution of the Incidence of Massive Galaxy-Galaxy Pairs from z=3 to z~0
• Late-stage galaxy mergers in COSMOS to z~1
• Deep learning for galaxy surface brightness profile fitting
• The Bulge-Disk Decomposed Evolution of Massive Galaxies at 1<z<3 in CANDELS
• The MUSE Hubble Ultra Deep Field Survey. IX. Evolution of galaxy merger fraction since z~6
• Galaxy Mergers at z>1 in the HUDF: Evidence for a Peak in the Major Merger Rate of Massive Galaxies
• Star Formation and Clumps in Cosmological Galaxy Simulations with Radiation Pressure Feedback
• The zCOSMOS redshift survey : Influence of luminosity, mass and environment on the galaxy merger rate

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