论文标题
HSC-SSP中的大量早期型星系：潮汐特征的通量分数和合并率
Massive Early-Type Galaxies in the HSC-SSP: Flux Fraction of Tidal Features and Merger Rates
论文作者
论文摘要
在这里，我们介绍了关于大型早期型星系（ETG）围绕潮汐特征的统计研究。利用2649 ETG的潮汐特征（$ f _ {\ rm tidal} $）的潮汐分数（HSC-SSP）的2649 ETG中，具有恒星质量$ $ $ $ M _*> 10> 10^{11} m _ {\ odot $ z的$ sss $055555555555。 HSC-SSP的宽层达到$ \ sim 28.5 $ mag arcsec $^{ - 2} $ in $ i $ band。在此表面亮度极限下，我们发现这些星系中约有28％具有$ f _ {\ rm tidal}> 1 \％$的突出潮汐功能，其中ETG的数量呈$ f _ {\ rm tidal} $，并带有$ f _ {\ rm tidal} $，并带有logarithmic Slope logarithmic slope $ $ \ sim100 $ \ sim100 $。在我们进行探测的恒星质量范围内，我们注意到$ f _ {\ rm tidal} $从$ m _*\ oft10^{11} m _ {\ odot} $增加到2倍，达到$ m _ {\ odot} $ to $ m _**\ of10^\ oft10^{12} {12} m _ {\ odot} $。我们还执行配对以估计这些大规模ETG的合并速率。将合并费率与$ f _ {\ rm tidal} $相结合，我们估计潮汐功能的典型寿命为$ \ sim $ 3 Gyr，与以前的研究一致。
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 $0.05<z<0.15$ using automated techniques. The Wide-layer of HSC-SSP reaches a depth of $\sim 28.5$ mag arcsec$^{-2}$ in $i$-band. Under this surface brightness limit, we find that about 28 % of these galaxies harbor prominent tidal features with $f_{\rm tidal}>1\%$, 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.
