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We investigate the star formation and chemical evolution in the early universe by considering the merging history of the Galaxy in the {\Lambda}CDM scenario according to the extended Press-Schechter theory. We give some possible constraints…

Astrophysics of Galaxies · Physics 2015-05-19 Yutaka Komiya , Asao Habe , Takuma Suda , Masayuki Y. Fujimoto

The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the…

Astrophysics of Galaxies · Physics 2015-12-09 Michela Mapelli , Alessia Gualandris

We investigate how radiative feedback from the first stars affects the assembly of the first dwarf galaxies. We perform cosmological zoomed SPH simulations of a dwarf galaxy assembling inside a halo of virial mass 10^9 solar at z = 10. The…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-22 Andreas H. Pawlik , Milos Milosavljevic , Volker Bromm

In the framework of an ESO Large Programme high quality spectra of 70 very metal-poor dwarfs and giants were obtained with the VLT-UVES combination. This paper reports the detailed analyses of the 35 giants of the sample. At the exception…

Dwarf galaxy star formation histories are theoretically expected to be bursty, potentially leaving distinct imprints on their chemical evolution. We propose that episodic starbursts with quiescent periods longer than $\sim$100 Myr should…

Astrophysics of Galaxies · Physics 2025-01-20 Yuan-Sen Ting , Alexander P. Ji

We apply the spectral energy distribution (SED) fitting code ProSpect to multiwavelength imaging for $\sim$7,000 galaxies from the GAMA survey at $z<0.06$, in order to extract their star formation histories. We combine a parametric…

We present uniformly measured star formation histories (SFHs) of 60 nearby (D~4Mpc) dwarf galaxies based on CMDs of resolved stellar populations from images taken with HST as part of the ACS Nearby Galaxy Survey Treasury program (ANGST).…

The epoch of reionization and formation of first stars are inter-linked topics that are of considerable interest. We use a simplified approach for studying formation of stars in collapsed haloes, and the resulting ionization of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 J. S. Bagla , Girish Kulkarni , T. Padmanabhan

Motivated by the recently improved knowledge on the kinematic and chemical properties of the Galactic metal-poor stars, we present the numerical simulation for the formation of the Galactic stellar halo to interpret the observational…

Astrophysics · Physics 2009-10-31 Kenji Bekki , Masashi Chiba

The first stars fundamentally transformed the early Universe through their production of energetic radiation and the first heavy chemical elements. The impact on cosmic evolution sensitively depends on their initial mass function (IMF),…

Astrophysics · Physics 2009-11-13 Anna Frebel , Jarrett L. Johnson , Volker Bromm

We present the results of VLT-MUSE integral field spectroscopy of SECCO1, a faint, star-forming stellar system recently discovered as the stellar counterpart of an Ultra Compact High Velocity Cloud (HVC274.68+74.0), very likely residing…

Clusters of galaxies allow a direct estimate of the metallicity and metal production yield on the largest scale so far. It is argued that cluster metallicity ($\sim 1/3$ solar) should be taken as representative of the low-$z$ universe as a…

Astrophysics · Physics 2007-05-23 Alvio Renzini

Initial conditions are set by Big bang nucleosynthesis from which we know that 90 per cent of baryons are dark and have essentially unknown chemical composition. In our own Galaxy, there are many clues from individual stars in different…

Astrophysics · Physics 2007-05-23 B. E. J. Pagel

The massive First Stars (the first ones to contribute to the chemical enrichment of the Universe due to their short lifetimes) are long dead, and even though efforts to directly observe them in high redshift galaxies are underway, a step…

Astrophysics of Galaxies · Physics 2013-01-10 Gabriele Cescutti , Cristina Chiappini

In this paper, the first in a series on galaxy formation before reionization, we focus on understanding what determines the size and morphology of stellar objects in the first low mass galaxies, using parsec- scale cosmological simulations…

Astrophysics of Galaxies · Physics 2016-11-15 Massimo Ricotti , Owen H. Parry , Nickolay Y. Gnedin

The star formation main sequence (SFMS) is a tight relation between the galaxy star formation rate (SFR) and its total stellar mass ($M_\star$). Early-type galaxies (ETGs) are often considered as low-SFR outliers of this relation. We study,…

Astrophysics of Galaxies · Physics 2019-07-17 J. Mendez-Abreu , S. F. Sanchez , A. de Lorenzo-Caceres

We investigate the chemo-dynamical effects of multiple supernova explosions in the central region of primordial galaxies using three-dimensional hydrodynamical simulations of the inhomogenous interstellar medium down to parsec-scales. We…

Astrophysics · Physics 2009-11-07 K. Wada , A. Venkatesan

This paper reviews recent abundance results of local dSph giants. All dSph systems seem to show evidence of slow star formation rates, compared to the Milky Way, based on the most metal-rich stars exhibiting low [even-Z/Fe] ratios and high…

Astrophysics · Physics 2007-05-23 Matthew Shetrone

Theories of thick disk formation can be differentiated by measurements of stellar elemental abundances. We have undertaken a study of metal-poor stars selected from the RAVE spectroscopic survey of bright stars to establish whether or not…

Aim: We establish the mean metallicity from high-resolution spectroscopy for the recently found dwarf spheroidal galaxy Bootes I and test whether it is a common feature for ultra-faint dwarf spheroidal galaxies to show signs of…

Astrophysics of Galaxies · Physics 2009-12-08 S. Feltzing , K. Eriksson , J. Kleyna , M. I. Wilkinson