Related papers: The first stars: Where did they form?
We study star formation history and stellar metallicity distribution in galaxies in a Lambda cold dark matter universe using a hydrodynamic cosmological simulation. Our model predicts star formation rate declining in time exponentially from…
The empirical model of Lu et al. 2014 is updated with recent data and used to study galaxy star formation and assembly histories. At $z > 2$, the predicted galaxy stellar mass functions are steep, and a significant amount of star formation…
Formation process(es) of galactic bulges are not yet clarified although several mechanisms have been proposed. In a previous study, we suggested one possibility that galactic bulges have been formed from the cold gas inflowing through…
The formation of the first galaxies at redshifts z~10-15 signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding their assembly process with…
Cosmic objects with magnetic fields (quasars, radiogalaxies) are observed at redshifts $z\geq 7$ (Wang et al., 2021, Fan et al., 2023, Yang et al., 2024) and more (for instance, for $z = 10.073\pm 0.002$, Goulding et al., 2023) indicates…
The earliest stars to form in the Universe were the first sources of light, heat and metals after the Big Bang. The products of their evolution will have had a profound impact on subsequent generations of stars. Recent studies of primordial…
The emergence of the first sources of light at redshifts of z ~ 10-30 signaled the transition from the simple initial state of the Universe to one of increasing complexity. We review recent progress in our understanding of the formation of…
The star formation rate history of the Milky Way is derived using the chromospheric age distribution for 552 stars in the solar neighborhood. The stars sample birthsites distributed over a very large range of distances because of orbital…
The formation of the first galaxies at redshifts z ~ 10-15 signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding their assembly process…
The first stars in the Universe form when chemically pristine gas heats as it falls into dark matter potential wells, cools radiatively due to the formation of molecular hydrogen, and becomes self-gravitating. We demonstrate with…
Understanding the formation of the first stars is one of the frontier topics in modern astrophysics and cosmology. Their emergence signaled the end of the cosmic dark ages, a few hundred million years after the Big Bang, leading to a…
In popular cold dark matter cosmological scenarios, stars may have first appeared in significant numbers around a redshift of 10 or so, as the gas within protogalactic halos with virial temperatures in excess of 20,000 K (corresponding to…
Our current understanding of the star formation histories of early-type galaxies is reviewed, in the context of recent observational studies of their ultra-violet (UV) properties. Combination of UV and optical spectro-photometric data…
Despite the huge amount of photometric and spectroscopic efforts targetting the Galactic bulge over the past few years, its age distribution remains controversial owing to both the complexity of determining the age of individual stars and…
I review recent progress in understanding the formation of the first stars and quasars. The initial conditions for their emergence are given by the now firmly established model of cosmological structure formation. Numerical simulations of…
The first dwarf galaxies, which constitute the building blocks of the collapsed objects we find today in the Universe, had formed hundreds of millions of years after the big bang. This pedagogical review describes the early growth of their…
The first generation of stars were born a few hundred million years after the big bang. These stars synthesized elements heavier than H and He, that are later expelled into the interstellar medium, initiating the rise of metals. Within this…
A number of years ago the estimates of astronomers and astrophysicists were that the earliest galaxies took about 2.5 to 3 billion years to form, that is, that they did not appear until 2.5 to 3 billion years after the Big Bang. Those…
The first stars in the Universe are predicted to have been much more massive than the Sun. Gravitational condensation accompanied by cooling of the primordial gas due to molecular hydrogen, yields a minimum fragmentation scale of a few…
The gas accretion and star-formation histories of galaxies like the Milky Way remain an outstanding problem in astrophysics. Observations show that 8 billion years ago, the progenitors to Milky Way-mass galaxies were forming stars 30 times…