Major merging history in CANDELS. I. Evolution of the incidence of massive galaxy–galaxy pairs from z = 3 to z ∼ 0

Mantha, Kameswara Bharadwaj; McIntosh, Daniel H.; Brennan, Ryan; Ferguson, Henry C.; Kodra, Dritan; Newman, Jeffrey A.; Rafelski, Marc; Somerville, Rachel S.; Conselice, Christopher J.; Cook, Joshua S.; Hathi, Nimish P.; Koo, David C.; Lotz, Jennifer M.; Simmons, Brooke D.; Straughn, Amber N.; Snyder, Gregory F.; Wuyts, Stijn; Bell, Eric F; Dekel, Avishai; Kartaltepe, Jeyhan; Kocevski, Dale D.; Koekemoer, Anton M.; Lee, Seong-Kook; Lucas, Ray A.; Pacifici, Camilla; Peth, Michael A.; Barro, Guillermo; Dahlen, Tomas; Finkelstein, Steven L.; Fontana, Adriano; Galametz, Audrey; Grogin, Norman A.; Guo, Yicheng; Mobasher, Bahram; Nayyeri, Hooshang; P�rez-Gonz�lez, Pablo G.; Pforr, Janine; Santini, Paola; Stefanon, Mauro; Wiklind, Tommy

Abstract

The rate of major galaxy–galaxy merging is theoretically predicted to steadily increase with redshift during the peak epoch of massive galaxy development (1 ≤ z ≤ 3). We use close-pair statistics to objectively study the incidence of massive galaxies (stellar M1 > 2 × 1010 M⊙) hosting major companions (1 ≤ M1/M2 ≤ 4; i.e. 4:1) companions at z > 1. We show that these evolutionary trends are statistically robust to changes in companion proximity. We find disagreements between published results are resolved when selection criteria are closely matched. If we compute merger rates using constant fraction-to-rate conversion factors (Cmerg,pair = 0.6 and Tobs,pair = 0.65 Gyr), we find that MR rates disagree with theoretical predictions at z > 1.5. Instead, if we use an evolving Tobs,pair(z) ∝ (1 + z)−2 from Snyder et al., our MR-based rates agree with theory at 0 < z < 3. Our analysis underscores the need for detailed calibration of Cmerg,pair and Tobs,pair as a function of redshift, mass, and companion selection criteria to better constrain the empirical major merger history.

Citation

Mantha, K. B., McIntosh, D. H., Brennan, R., Ferguson, H. C., Kodra, D., Newman, J. A., …Wiklind, T. (2018). Major merging history in CANDELS. I. Evolution of the incidence of massive galaxy–galaxy pairs from z = 3 to z ∼ 0. Monthly Notices of the Royal Astronomical Society, 475(2), https://doi.org/10.1093/mnras/stx3260

• Journal Article Type: Article
• Acceptance Date: Dec 13, 2017
• Online Publication Date: Dec 20, 2017
• Publication Date: Apr 1, 2018
• Deposit Date: May 14, 2018
• Publicly Available Date: May 14, 2018
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 475
• Issue: 2
• DOI: https://doi.org/10.1093/mnras/stx3260
• Keywords: galaxies: evolution, galaxies: high-redshift, galaxies: interactions, galaxies: statistics
• Public URL: https://nottingham-repository.worktribe.com/output/922760
• Publisher URL: https://doi.org/10.1093/mnras/stx3260