دورية
Galaxy morphologies revealed with Subaru HSC and super-resolution techniques. I. Major merger fractions of LUV∼ 3–15 L*UVdropout galaxies at z∼ 4–7†
| العنوان: | Galaxy morphologies revealed with Subaru HSC and super-resolution techniques. I. Major merger fractions of LUV∼ 3–15 L*UVdropout galaxies at z∼ 4–7† |
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| المؤلفون: | Shibuya, Takatoshi, Miura, Noriaki, Iwadate, Kenji, Fujimoto, Seiji, Harikane, Yuichi, Toba, Yoshiki, Umayahara, Takuya, Ito, Yohito |
| المصدر: | Publications of the Astronomical Society of Japan; February 2022, Vol. 74 Issue: 1 p73-91, 19p |
| مستخلص: | We perform a super-resolution analysis of the Subaru Hyper Suprime-Cam (HSC) images to estimate the major merger fractions of z∼ 4–7 dropout galaxies at the bright end of galaxy UV luminosity functions (LFs). Our super-resolution technique improves the spatial resolution of the ground-based HSC images, from ∼1″ to $\lesssim \!\!{0{^{\prime \prime }_{.}}1}$, which is comparable to that of the Hubble Space Telescope, allowing us to identify z∼ 4–7 bright major mergers at a high completeness value of $\gtrsim \!\!90\%$. We apply the super-resolution technique to 6412, 16, 94, and 13 very bright dropout galaxies at z∼ 4, 5, 6, and 7, respectively, in a UV luminosity range of LUV∼ 3–$15\, L_{\rm UV}^*$corresponding to −24 ≲ MUV≲ −22. The major merger fractions are estimated to be $f_{\rm merger}\sim 10\%$–$20\%$at z∼ 4 and $\sim 50\%$–$70\%$at z∼ 5–7, which shows no fmergerdifference compared to those of a control faint galaxy sample. Based on the fmergerestimates, we verify contributions of source blending effects and major mergers to the bright-end of double power-law (DPL) shape of z∼ 4–7 galaxy UV LFs. While these two effects partly explain the DPL shape at LUV∼ 3–$10\, L_{\rm UV}^*$, the DPL shape cannot be explained at the very bright end of $L_{\rm UV}\gtrsim 10\, L_{\rm UV}^*$, even after the AGN contribution is subtracted. The results support scenarios in which other additional mechanisms such as insignificant mass quenching and low dust obscuration contribute to the DPL shape of galaxy UV LFs. |
| قاعدة البيانات: | Supplemental Index |
| تدمد: | 00046264 2053051X |
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| DOI: | 10.1093/pasj/psab111 |