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arXiv · 2108.07125

The evolution of merger fraction of galaxies at z < 0.6 depending on the star formation mode in the AKARI NEP Wide field

Eunbin Kim·Ho Seong Hwang·Woong-Seob Jeong·Seong Jin Kim·Denis Burgarella·Tomotsugu Goto·Tetsuya Hashimoto·Young-Soo Jo·Jong Chul Lee·Matthew Malkan·Chris Pearson·Hyunjin Shim·Yoshiki Toba·Simon C. -C. Ho·Daryl Joe Santos·Hiroyuki Ikeda·Helen K. Kim·Takamitsu Miyaji·Hideo Matsuhara·Nagisa Oi·Toshinobu Takagi·Ting-Wen Wang
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Abstract

We study the galaxy merger fraction and its dependence on star formation mode in the5.4 square degrees of the North Ecliptic Pole-Wide field. We select 6352 galaxies withAKARI 9{\mu}m detections, and identify mergers among them using the Gini coefficientand M20derived from the Subaru/HSC optical images. We obtain the total infraredluminosity and star formation rate of galaxies using the spectral energy distributiontemplates based on one band, AKARI 9{\mu}m. We classify galaxies into three differentstar formation modes (i.e. starbursts, main sequence, and quiescent galaxies) andcalculate the merger fractions for each. We find that the merger fractions of galaxiesincrease with redshift atz<0.6. The merger fractions of starbursts are higher thanthose of main sequence and quiescent galaxies in all redshift bins. We also examinethe merger fractions of far-infrared detected galaxies which have at least one detectionfromHerschel/SPIRE. We find thatHerscheldetected galaxies have higher mergerfraction compared to non-Herscheldetected galaxies, and bothHerscheldetected andnon-Herscheldetected galaxies show clearly different merger fractions depending onthe star formation modes.

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Eunbin Kim, Ho Seong Hwang, Woong-Seob Jeong, Seong Jin Kim, Denis Burgarella, Tomotsugu Goto, Tetsuya Hashimoto, Young-Soo Jo, Jong Chul Lee, Matthew Malkan, Chris Pearson, Hyunjin Shim, Yoshiki Toba, Simon C. -C. Ho, Daryl Joe Santos, Hiroyuki Ikeda, Helen K. Kim, Takamitsu Miyaji, Hideo Matsuhara, Nagisa Oi, Toshinobu Takagi, Ting-Wen Wang. 2021-08-16. The evolution of merger fraction of galaxies at z < 0.6 depending on the star formation mode in the AKARI NEP Wide field. https://doi.org/10.1093/mnras/stab2090

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