The structures of distant galaxies – III. The merger history of over 20 000 massive galaxies at z < 1.2

By Christopher J. Conselice, Cui Yang, A. Bluck. 2008

148 citations recorded by the source corpus.

Utilizing deep Hubble Space Telescope imaging from the two largest field galaxy surveys, the Extended Groth Strip and the Cosmic Evolution Survey (COSMOS), we examine the structural properties, and derive the merger history for 21 902 galaxies withM∗ > 10 10 Matz 10 10 M� , the merger fraction can be parametrized by f m = f 0 × (1 + z) m with the power-law slope m = 2.3 ± 0.4. By using the best available z = 0 prior the slope increases to m = 3.8 ± 0.2, showing how critical the measurement of local merger properties is for deriving the evolution of the merger fraction. We furthermore show that the merger fraction derived through structure is roughly a factor of 3-6 higher than pair fractions. Based on the latest cosmological simulations of mergers, we show that this ratio is predicted, and that both methods are likely tracing the merger fraction and rate properly. We calculate, utilizing merger time-scales from simulations and previously published merger fractions within the Hubble Deep and Ultra Deep Fields, that the merger rate of galaxies with M∗ > 10 10 Mincreases linearly between z = 0.7 and 3. Finally, we show that a typical galaxy with a stellar mass of M∗ > 10 10 Mundergoes between 1 and 2 major mergers at z < 1.2.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/9392561e7e7d723bde18682e2c16f9512c87aa19

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Citations in the corpus

Early type galaxies have been the predominant morphological class for massive galaxies since only z~1 (2011, background): “This latter fact agrees with merging becoming more important in massive galaxy evolution at increasing redshift (Conselice et al. 2009, Bluck et al. 2009, 2011).”
MERGERS IN ΛCDM: UNCERTAINTIES IN THEORETICAL PREDICTIONS AND INTERPRETATIONS OF THE MERGER RATE (2010, background): “…are in mergers – strongly morphologically disturbed or in “major” similar-mass pairs about to merge (at small scales and small relative velocities) (Bridge et al. 2007, 2010; Kartaltepe et al. 2007; Conselice et al. 2009; Jogee et al. 2009; Lotz et al. 2008b; Lin et al. 2008; Robaina et al. 2010).”
The Evolution of Galaxy Structure Over Cosmic Time (2014, methodology): “Using the merger time scale, the merger rate per galaxy is thereby defined by the param- eter Γ (e.g. Bluck et al. 2009; Conselice et al. 2009), Γ(M∗, z) = τm fgm .”
CAN MINOR MERGING ACCOUNT FOR THE SIZE GROWTH OF QUIESCENT GALAXIES? NEW RESULTS FROM THE CANDELS SURVEY (2011, background): “Several authors have inferred merger rates from morphological signatures (e.g., Lotz et al. 2008a, Conselice et al. 2009, Bridge et al. 2010).”
MERGERS AND BULGE FORMATION IN ΛCDM: WHICH MERGERS MATTER? (2009, methodology): “In particular, the observations using a calibration of Gini-M20 or CAS pecifically matched to high-resolution hydrodynamic major merger simulations (e.g. Lotz et al. 2008b; Conselice et al. 2009) agree reasonably well with the predictedµgal > 1/3 fractions.”
Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions (2011, background): “…the mechanism that causes this transition will be the subject of future work, but it appears unlikely that mergers play a dominant role at these moderate redshifts, given the low merger fraction (∼ 5 per cent or less) observed at low redshift by e.g. Conselice et al. (2009) and Lotz et al. (2011).”
The effects of gas on morphological transformation in mergers: implications for bulge and disc demographics (2009, background): “…in a shorter time than the duration of the merger itself, and correcting for the expected duty cycles/lifetimes of these events, a large fraction of these low-mass galaxies should have experienced a violent event in the last ∼10 Gyr (Hopkins et al. 2007; Lotz et al. 2008a; Conselice et al. 2009).”
THE MAJOR AND MINOR GALAXY MERGER RATES AT z < 1.5 (2011, methodology): “Conselice et al. (2009) computed asymmetry fractions for galaxies at 0.2 < z < 1.2 selected from the COSMOS (Scoville et al. 2007 ), GEMS (Rix et al. 2004), GOODS (Giavalisco et al. 2004) and AEGIS (Davis et al. 2007) HST surveys.”