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arXiv · 2207.14320

Massive Early-Type Galaxies in the HSC-SSP: Flux Fraction of Tidal Features and Merger Rates

Qifeng Huang·Lulu Fan
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Abstract

Here we present a statistical study on tidal features around massive early-type galaxies (ETGs). Utilizing the imaging data of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP), we measure the flux fraction of tidal features ($f_{\rm tidal}$) in 2649 ETGs with stellar mass $M_*>10^{11}M_{\odot}$ and redshift $0.05 1\%$, among which the number of ETGs decreases exponentially with $f_{\rm tidal}$, with a logarithmic slope of $\sim100$. Within the stellar mass range we probe, we note that $f_{\rm tidal}$ increases by a factor of 2 from $M_*\approx10^{11}M_{\odot}$ to $M_*\approx10^{12}M_{\odot}$. We also perform pair-count to estimate the merger rate of these massive ETGs. Combining the merger rates with $f_{\rm tidal}$, we estimate that the typical lifetime of tidal features is $\sim$ 3 Gyr, consistent with previous studies.

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Qifeng Huang, Lulu Fan. 2022-07-28. Massive Early-Type Galaxies in the HSC-SSP: Flux Fraction of Tidal Features and Merger Rates. https://doi.org/10.3847/1538-4365/ac85b1

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