Growth of First Galaxies: Impacts of Star Formation and Stellar Feedback

Yajima, H.; Nagamine, Kentaro; Zhu, Qirong; Khochfar, Sadegh; Dalla Vecchia, C.
Referencia bibliográfica

The Astrophysical Journal, Volume 846, Issue 1, article id. 30, 13 pp. (2017).

Fecha de publicación:
9
2017
Descripción
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 {M}{{h}}=2.4× {10}10 {h}-1 {M}ȯ (Halo-10), 1.6× {10}11 {h}-1 {M}ȯ (Halo-11), and 0.7× {10}12 {h}-1 {M}ȯ (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.
Proyectos relacionados
Project Image
Astrofísica Numérica: Formación y Evolución de Galaxias

Entre las cuestiones fundamentales en Astronomía y Astrofísica están la formación y evolución de galaxias. Las escalas de tiempo y tamaño son tan astronómicas que su observación en galaxias individuales es imposible. Solo con el uso de simulaciones numéricas es posible entender la formación de estructuras cósmicas dentro del actual marco

Claudio
Dalla Vecchia
El andamiaje invisible del espacio
Cosmología con Trazadores de la Estructura a Gran Escala del Universo

El Fondo Cósmico de Microondas (FCM) contiene la información estadística de las semillas primigenias que han dado lugar a la formación de todas las estructuras en el Universo. Su contrapartida natural en el Universo local es la distribución de las galaxias que surgen como resultado del crecimiento gravitatorio de aquellas fluctuaciones de densidad

FRANCISCO SHU
KITAURA JOYANES