TY - JOUR
T1 - Growth of First Galaxies
T2 - Impacts of Star Formation and Stellar Feedback
AU - Yajima, Hidenobu
AU - Nagamine, Kentaro
AU - Zhu, Qirong
AU - Khochfar, Sadegh
AU - Vecchia, Claudio Dalla
N1 - Funding Information:
The numerical simulations were performed on the computer cluster, Draco, at the Frontier Research Institute for Interdisciplinary Sciences of Tohoku University and Pluto in the Theoretical Astrophysics Group at Osaka University. This work is supported in part by the MEXT/JSPS KAKENHI Grant Number 15H06022 (H.Y.) and JP26247022 (K.N.). C.D.V. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under the 2015 Severo Ochoa program SEV-2015-0548, and grants AYA2014-58308 and RYC-2015-18078.
Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved.
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Recent observations have detected galaxies at high-redshift z ∼ 6-11, and revealed the diversity of their physical properties, from normal star-forming galaxies to starburst galaxies. To understand the properties of these observed galaxies, it is crucial to understand the star formation (SF) history of high-redshift galaxies under the influence of stellar feedback. In this work, we present the results of cosmological hydrodynamic simulations with zoom-in initial conditions, and investigate the formation of the first galaxies and their evolution toward observable galaxies at z ∼ 6. We focus on three different galaxies that end up in halos with masses Mh 2.4 ×1010h-1Mo(Halo-10), 1.6 × 1011 h-1 Mo (Halo-11), and 0.7 × 1012 h-1 Mo (Halo-12) at z = 6. Our simulations also probe the impacts of different subgrid assumptions, i.e., SF efficiency and cosmic reionization, on SF histories in the first galaxies. We find that SF occurs intermittently due to supernova (SN) feedback at z ≳ 10, and then it proceeds more smoothly as the halo mass grows at lower redshifts. Galactic disks are destroyed due to SN feedback, while galaxies in simulations with no feedback or lower SF efficiency models can sustain a galactic disk for long periods ≳ 10 Myr. The expulsion of gas at the galactic center also affects the inner dark matter density profile for a short period. Our simulated galaxies in Halo-11 and Halo-12 reproduce the SF rates and stellar masses of observed Lyα emitters at z ∼ 7-8 fairly well given the observational uncertainties.
AB - Recent observations have detected galaxies at high-redshift z ∼ 6-11, and revealed the diversity of their physical properties, from normal star-forming galaxies to starburst galaxies. To understand the properties of these observed galaxies, it is crucial to understand the star formation (SF) history of high-redshift galaxies under the influence of stellar feedback. In this work, we present the results of cosmological hydrodynamic simulations with zoom-in initial conditions, and investigate the formation of the first galaxies and their evolution toward observable galaxies at z ∼ 6. We focus on three different galaxies that end up in halos with masses Mh 2.4 ×1010h-1Mo(Halo-10), 1.6 × 1011 h-1 Mo (Halo-11), and 0.7 × 1012 h-1 Mo (Halo-12) at z = 6. Our simulations also probe the impacts of different subgrid assumptions, i.e., SF efficiency and cosmic reionization, on SF histories in the first galaxies. We find that SF occurs intermittently due to supernova (SN) feedback at z ≳ 10, and then it proceeds more smoothly as the halo mass grows at lower redshifts. Galactic disks are destroyed due to SN feedback, while galaxies in simulations with no feedback or lower SF efficiency models can sustain a galactic disk for long periods ≳ 10 Myr. The expulsion of gas at the galactic center also affects the inner dark matter density profile for a short period. Our simulated galaxies in Halo-11 and Halo-12 reproduce the SF rates and stellar masses of observed Lyα emitters at z ∼ 7-8 fairly well given the observational uncertainties.
KW - galaxies: ISM
KW - galaxies: evolution
KW - galaxies: formation
KW - galaxies: high-redshift
KW - methods: numerical
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U2 - 10.3847/1538-4357/aa82b5
DO - 10.3847/1538-4357/aa82b5
M3 - Article
AN - SCOPUS:85029088528
SN - 0004-637X
VL - 846
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 30
ER -