Advanced search
1 file | 3.19 MB

The pair faction of massive galaxies at 0 ≤ z ≤ 3

Author
Organization
Abstract
Using a mass-selected (M-star >= 10(11) M-circle dot) sample of 198 galaxies at 0 <= z <= 3.0 with Hubble Space Telescope/NICMOS H-160-band images from the COSMOS survey, we find evidence for the evolution of the pair fraction above z similar to 2, an epoch in which massive galaxies are believed to undergo significant structural and mass evolution. We observe that the pair fraction of massive galaxies is 0.15 +/- 0.08 at 1.7 <= z <= 3.0, where galaxy pairs are defined as massive galaxies having a companion of flux ratio from 1:1 to 1:4 within a projected separation of 30 kpc. This is slightly lower but still consistent with the pair fraction measured previously in other studies, and the merger fraction predicted in halo-occupation modeling. The redshift evolution of the pair fraction is described by a power law F(z) = (0.07 +/- 0.04) x (1 + z)(0.6 +/- 0.5). The merger rate is consistent with no redshift evolution; however it is difficult to constrain due to the limited sample size and the high uncertainties in the merging timescale. Based on the merger rate calculation, we estimate that a massive galaxy undergoes on average 1.1 +/- 0.5 major mergers from z = 3 to 0. The observed merger fraction is sufficient to explain the number density evolution of massive galaxies, but insufficient to explain the size evolution. This is a hint that mechanism(s) other than major merging may be required to increase the sizes of the massive, compact quiescent galaxies from z similar to 2 to 0.
Keywords
STAR-FORMING GALAXIES, HUBBLE-SPACE-TELESCOPE, GOODS NICMOS SURVEY, SIZE, EVOLUTION, ELLIPTIC GALAXIES, MERGER RATE, QUIESCENT GALAXIES, REDSHIFT, SURVEY, LAMBDA-CDM, FIELD GALAXIES, galaxies: evolution, galaxies: formation, galaxies: high-redshift

Downloads

  • The Pair Fraction of Massive Galaxies at 0 <= z <= 3.pdf
    • full text
    • |
    • open access
    • |
    • PDF
    • |
    • 3.19 MB

Citation

Please use this url to cite or link to this publication:

Chicago
Man, Allison WS, Sune Toft, Andrew W Zirm, Stijn Wuyts, and Arjen van der Wel. 2012. “The Pair Faction of Massive Galaxies at 0 ≤ z ≤ 3.” Astrophysical Journal 744 (2).
APA
Man, A. W., Toft, S., Zirm, A. W., Wuyts, S., & van der Wel, A. (2012). The pair faction of massive galaxies at 0 ≤ z ≤ 3. ASTROPHYSICAL JOURNAL, 744(2).
Vancouver
1.
Man AW, Toft S, Zirm AW, Wuyts S, van der Wel A. The pair faction of massive galaxies at 0 ≤ z ≤ 3. ASTROPHYSICAL JOURNAL. 2012;744(2).
MLA
Man, Allison WS, Sune Toft, Andrew W Zirm, et al. “The Pair Faction of Massive Galaxies at 0 ≤ z ≤ 3.” ASTROPHYSICAL JOURNAL 744.2 (2012): n. pag. Print.
@article{8575192,
  abstract     = {Using a mass-selected (M-star >= 10(11) M-circle dot) sample of 198 galaxies at 0 <= z <= 3.0 with Hubble Space Telescope/NICMOS H-160-band images from the COSMOS survey, we find evidence for the evolution of the pair fraction above z similar to 2, an epoch in which massive galaxies are believed to undergo significant structural and mass evolution. We observe that the pair fraction of massive galaxies is 0.15 +/- 0.08 at 1.7 <= z <= 3.0, where galaxy pairs are defined as massive galaxies having a companion of flux ratio from 1:1 to 1:4 within a projected separation of 30 kpc. This is slightly lower but still consistent with the pair fraction measured previously in other studies, and the merger fraction predicted in halo-occupation modeling. The redshift evolution of the pair fraction is described by a power law F(z) = (0.07 +/- 0.04) x (1 + z)(0.6 +/- 0.5). The merger rate is consistent with no redshift evolution; however it is difficult to constrain due to the limited sample size and the high uncertainties in the merging timescale. Based on the merger rate calculation, we estimate that a massive galaxy undergoes on average 1.1 +/- 0.5 major mergers from z = 3 to 0. The observed merger fraction is sufficient to explain the number density evolution of massive galaxies, but insufficient to explain the size evolution. This is a hint that mechanism(s) other than major merging may be required to increase the sizes of the massive, compact quiescent galaxies from z similar to 2 to 0.},
  articleno    = {85},
  author       = {Man, Allison WS and Toft, Sune and Zirm, Andrew W and Wuyts, Stijn and van der Wel, Arjen},
  issn         = {0004-637X},
  journal      = {ASTROPHYSICAL JOURNAL},
  keywords     = {STAR-FORMING GALAXIES,HUBBLE-SPACE-TELESCOPE,GOODS NICMOS SURVEY,SIZE,EVOLUTION,ELLIPTIC GALAXIES,MERGER RATE,QUIESCENT GALAXIES,REDSHIFT,SURVEY,LAMBDA-CDM,FIELD GALAXIES,galaxies: evolution,galaxies: formation,galaxies: high-redshift},
  language     = {eng},
  number       = {2},
  pages        = {7},
  title        = {The pair faction of massive galaxies at 0 ≤ z ≤ 3},
  url          = {http://dx.doi.org/10.1088/0004-637X/744/2/85},
  volume       = {744},
  year         = {2012},
}

Altmetric
View in Altmetric
Web of Science
Times cited: