Browsing by Author "Ma, Chung-Pei"

Now showing items 1-7 of 7

    • An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations 

      Torrey, Paul; Wellons, Sarah; Machado, Francisco; Griffen, Brendan; Nelson, Dylan; Rodriguez-Gomez, Vicente; McKinnon, Ryan; Pillepich, Annalisa; Ma, Chung-Pei; Vogelsberger, Mark; Springel, Volker; Hernquist, Lars (Oxford University Press, 2015)
      We present an analysis of the evolving comoving cumulative number density of galaxy populations found in the Illustris simulation. Cumulative number density is commonly used to link galaxy populations across different ...

    • Mergers In {lambda}cdm: Uncertainties in Theoretical Predictions and Interpretations of the Merger Rate 

      Hopkins, Philip F.; Croton, Darren; Bundy, Kevin; Khochfar, Sadegh; Bosch, Frank van den; Somerville, Rachel S.; Wetzel, Andrew; Keres, Dusan; Hernquist, Lars; Stewart, Kyle; Younger, Joshua D.; Genel, Shy; Ma, Chung-Pei; Hopkins, Philip; Croton, Darren; Bundy, Kevin; Khochfar, Sadegh; Bosch, Frank; Somerville, Rachel; Wetzel, Andrew; Keres, Dusan; Hernquist, Lars; Stewart, Kyle; Younger, Joshua; Genel, Shy; Ma, Chung-Pei (American Astronomical Society, 2010)
      Different theoretical methodologies lead to order-of-magnitude variations in predicted galaxy-galaxy merger rates. We examine how this arises and quantify the dominant uncertainties. Modeling of dark matter and galaxy ...

    • The stellar mass assembly of galaxies in the Illustris simulation: growth by mergers and the spatial distribution of accreted stars 

      Rodriguez-Gomez, Vicente; Pillepich, Annalisa; Sales, Laura V.; Genel, Shy; Vogelsberger, Mark; Zhu, Qirong; Wellons, Sarah; Nelson, Dylan; Torrey, Paul; Springel, Volker; Ma, Chung-Pei; Hernquist, Lars Eric (Oxford University Press (OUP), 2016)
      We use the Illustris simulation to study the relative contributions of in situ star formation and stellar accretion to the build-up of galaxies over an unprecedentedly wide range of masses (M* = 109-1012 M⊙), galaxy types, ...

    • The diverse evolutionary paths of simulated high- z massive, compact galaxies to z = 0 

      Wellons, Sarah; Torrey, Paul; Ma, Chung-Pei; Rodriguez-Gomez, Vicente; Pillepich, Annalisa; Nelson, Dylan; Genel, Shy; Vogelsberger, Mark; Hernquist, Lars (Oxford University Press, 2016)
      Massive quiescent galaxies have much smaller physical sizes at high redshift than today. The strong evolution of galaxy size may be caused by progenitor bias, major and minor mergers, adiabatic expansion, and/or renewed ...

    • The effects of gas on morphological transformation in mergers: implications for bulge and disc demographics 

      Hopkins, Philip F.; Somerville, Rachel S.; Cox, Thomas J.; Hernquist, Lars; Jogee, Shardha; Kereš, Dusan; Ma, Chung-Pei; Robertson, Brant; Stewart, Kyle (Oxford University Press, 2009)
      Transformation of discs into spheroids via mergers is a well-accepted element of galaxy formation models. However, recent simulations have shown that the bulge formation is suppressed in increasingly gas-rich mergers. We ...

    • The formation of massive, compact galaxies at z = 2 in the Illustris simulation 

      Wellons, Sarah; Torrey, Paul; Ma, Chung-Pei; Rodriguez-Gomez, Vicente; Vogelsberger, Mark; Kriek, Mariska; van Dokkum, Pieter; Nelson, Erica; Genel, Shy; Pillepich, Annalisa; Springel, Volker; Sijacki, Debora; Snyder, Gregory; Nelson, Dylan; Sales, Laura; Hernquist, Lars (Oxford University Press, 2015)
      Massive, quiescent galaxies at high redshift have been found to be considerably more compact than galaxies of similar mass in the local universe. How these compact galaxies formed has yet to be determined, though several ...

    • The merger rate of galaxies in the Illustris simulation: a comparison with observations and semi-empirical models 

      Rodriguez-Gomez, Vicente; Genel, Shy; Vogelsberger, Mark; Sijacki, Debora; Pillepich, Annalisa; Sales, Laura V.; Torrey, Paul; Snyder, Greg; Nelson, Dylan; Springel, Volker; Ma, Chung-Pei; Hernquist, Lars (Oxford University Press, 2015)
      We have constructed merger trees for galaxies in the Illustris simulation by directly tracking the baryonic content of subhaloes. These merger trees are used to calculate the galaxy-galaxy merger rate as a function of ...