Ongoing growth of the brightest cluster galaxies via major dry mergers in the last similar to 6 Gyr

	Ongoing growth of the brightest cluster galaxies via major dry mergers in the last similar to 6 Gyr
	Liu, F. S.1,2; Lei, F. J.2,3; Meng, X. M.3; Jiang, D. F.2
刊名	MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
	2015-02-21
卷号	447 期号:2 页码:1491-1497
关键词	galaxies: clusters: general galaxies: elliptical and lenticular, cD galaxies: photometry
英文摘要	Brightest cluster galaxies (BCGs) might have been assembled relatively late (z < 1) via mergers. By exploiting the high-resolution HST/ACS imaging, we find four BCGs (COSMOS-P 125516, 102810, 036694 and 089357) in major dry merging in 29 X-ray clusters at 0.3 <= z <= 0.6 in the Cosmological Evolutionary Survey (COSMOS). These BCGs show prominent but quiescent double nuclei with a magnitude difference of delta m < 1.5 and a projected separation of r(p) < 10 kpc. Clear signatures of interaction such as extended plumes and/or significant asymmetries are also observed in their residual images. We infer a major merger rate of 0.55 +/- 0.27 merger per Gyr at z similar to 0.43 assuming the merger time-scale estimate of Kitzbichler & White. This inferred rate is significantly higher than the rate in the local Universe (0.12 +/- 0.03 at z similar to 0.07) presented by Liu et al. We estimate that present-day BCGs increase their luminosity (mass) by similar to 35 +/- 15 per cent (f(mass)/0.5) via major dry mergers since z = 0.6, where f(mass) is the mean mass fraction of companion galaxies accreted on to the central ones. Although the statistical uncertainty due to our small sample size is relatively large, our finding is consistent with both recent observational and theoretical results. Furthermore, in conjunction with our previous findings by Liu et al., the discovery of these intermediate-redshift merging BCGs is clear evidence of ongoing assembly of BCGs via major dry mergers over the last similar to 6 Gyr.
收录类别	SCI
语种	英语
WOS记录号	WOS:000350272900040
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/5733]
专题	国家天文台_空间科学研究部
作者单位	1.Shenyang Normal Univ, Ctr Theoret Phys & Astrophys, Shenyang 110034, Peoples R China 2.Shenyang Normal Univ, Coll Phys Sci & Technol, Shenyang 110034, Peoples R China 3.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
推荐引用方式 GB/T 7714	Liu, F. S.,Lei, F. J.,Meng, X. M.,et al. Ongoing growth of the brightest cluster galaxies via major dry mergers in the last similar to 6 Gyr[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2015,447(2):1491-1497.
APA	Liu, F. S.,Lei, F. J.,Meng, X. M.,&Jiang, D. F..(2015).Ongoing growth of the brightest cluster galaxies via major dry mergers in the last similar to 6 Gyr.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,447(2),1491-1497.
MLA	Liu, F. S.,et al."Ongoing growth of the brightest cluster galaxies via major dry mergers in the last similar to 6 Gyr".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 447.2(2015):1491-1497.