TY - JOUR
T1 - Evolution of the mass, size, and star formation rate in high redshift merging galaxies
T2 - MIRAGE-A new sample of simulations with detailed stellar feedback
AU - Perret, V.
AU - Renaud, F.
AU - Epinat, B.
AU - Amram, P.
AU - Bournaud, F.
AU - Contini, T.
AU - Teyssier, R.
AU - Lambert, J. C.
N1 - Funding Information:
We thank the anonymous referee for the useful comments that greatly improved this paper. We thank the whole MASSIV team for encouraging this project with stimulating discussions. The simulations presented in this work were performed at the Très Grand Centre de Calcul of CEA under GENCI allocations 2012-GEN 2192 and 2013-GEN2192, and at the LRZ SuperMUC facility under PRACE allocation number 50816. F.R. and F.B. acknowledge funding from the EC through grant ERC-StG-257720. We thank J. Billing for distributing of the starscream code under the GPL license. Snapshots format conversions were managed using the UNSIO library ( http://projets.lam.fr/projects/unsio ).
PY - 2014/2
Y1 - 2014/2
N2 - Context. In Λ-CDM models, galaxies are thought to grow both through continuous cold gas accretion coming from the cosmic web and episodic merger events. The relative importance of these different mechanisms at different cosmic epochs is nevertheless not yet understood well. Aims. We aim to address questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1 < z < 2, an epoch that corresponds to the peak of cosmic star formation history. A significant fraction of Milky Way-like galaxies are thought to have undergone an unstable clumpy phase at this early stage. We focus on the behavior of the young clumpy disks when galaxies are undergoing gas-rich galaxy mergers. Methods. Using the adaptive mesh-refinement code RAMSES, we build the Merging and Isolated high redshift Adaptive mesh refinement Galaxies (MIRAGE) sample. It is composed of 20 mergers and 3 isolated idealized disks simulations, which sample disk orientations and merger masses. Our simulations can reach a physical resolution of 7 parsecs, and include star formation, metal line cooling, metallicity advection, and a recent physically-motivated implementation of stellar feedback that encompasses OB-type stars radiative pressure, photo-ionization heating, and supernovae. Results. The star formation history of isolated disks shows a stochastic star formation rate, which proceeds from the complex behavior of the giant clumps. Our minor and major gas-rich merger simulations do not trigger starbursts, suggesting a saturation of the star formation due to the detailed accounting of stellar feedback processes in a turbulent and clumpy interstellar medium fed by substantial accretion from the circumgalactic medium. Our simulations are close to the normal regime of the disk-like star formation on a Schmidt-Kennicutt diagram. The mass-size relation and its rate of evolution in the redshift range 1 < z < 2 matches observations, suggesting that the inside-out growth mechanisms of the stellar disk do not necessarily require cold accretion.
AB - Context. In Λ-CDM models, galaxies are thought to grow both through continuous cold gas accretion coming from the cosmic web and episodic merger events. The relative importance of these different mechanisms at different cosmic epochs is nevertheless not yet understood well. Aims. We aim to address questions related to galaxy mass assembly through major and minor wet merging processes in the redshift range 1 < z < 2, an epoch that corresponds to the peak of cosmic star formation history. A significant fraction of Milky Way-like galaxies are thought to have undergone an unstable clumpy phase at this early stage. We focus on the behavior of the young clumpy disks when galaxies are undergoing gas-rich galaxy mergers. Methods. Using the adaptive mesh-refinement code RAMSES, we build the Merging and Isolated high redshift Adaptive mesh refinement Galaxies (MIRAGE) sample. It is composed of 20 mergers and 3 isolated idealized disks simulations, which sample disk orientations and merger masses. Our simulations can reach a physical resolution of 7 parsecs, and include star formation, metal line cooling, metallicity advection, and a recent physically-motivated implementation of stellar feedback that encompasses OB-type stars radiative pressure, photo-ionization heating, and supernovae. Results. The star formation history of isolated disks shows a stochastic star formation rate, which proceeds from the complex behavior of the giant clumps. Our minor and major gas-rich merger simulations do not trigger starbursts, suggesting a saturation of the star formation due to the detailed accounting of stellar feedback processes in a turbulent and clumpy interstellar medium fed by substantial accretion from the circumgalactic medium. Our simulations are close to the normal regime of the disk-like star formation on a Schmidt-Kennicutt diagram. The mass-size relation and its rate of evolution in the redshift range 1 < z < 2 matches observations, suggesting that the inside-out growth mechanisms of the stellar disk do not necessarily require cold accretion.
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: high-redshift
KW - Galaxies: interactions
KW - Galaxies: star formation
KW - Methods: numerical
UR - http://www.scopus.com/inward/record.url?scp=84893374602&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893374602&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201322395
DO - 10.1051/0004-6361/201322395
M3 - Article
AN - SCOPUS:84893374602
SN - 0004-6361
VL - 562
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A1
ER -