English
Related papers

Related papers: Zero metallicity stellar sources and the reionizat…

200 papers

Early results from the JWST observations have reported a surprisingly high number of UV-bright galaxies at $z \geq 10$, which appears to challenge the theoretical predictions from standard galaxy formation models in the $\Lambda$CDM…

Astrophysics of Galaxies · Physics 2024-07-30 Anirban Chakraborty , Tirthankar Roy Choudhury

We find that the amount and nature of the assumed ionizing background can strongly affect galaxy formation and evolution. Galaxy evolution simulations typically incorporate an ultraviolet background which falls off rapidly above z=3; e.g.,…

Astrophysics of Galaxies · Physics 2014-11-20 D. Clay Hambrick , Jeremiah P. Ostriker , Thorsten Naab , Peter H. Johansson

We study the influence of gas metallicity, turbulence, and non-equilibrium chemistry on the evolution of the two-phase interstellar medium (warm and cold atomic phases), and thereby constrain the initial conditions for star formation…

Astrophysics of Galaxies · Physics 2015-05-27 S. Walch , R. Wuensch , A. Burkert , S. Glover , A. Whitworth

The physical origin of low escape fractions of ionizing radiation derived from massive star-forming galaxies at $z\sim3$-$4$ is not well understood. We perform idealised disc galaxy simulations to understand how galactic properties such as…

Astrophysics of Galaxies · Physics 2020-10-21 Taehwa Yoo , Taysun Kimm , Joakim Rosdahl

Massive stars played a key role in the early evolution of the Universe. They formed with the first halos and started the re-ionisation. It is therefore very important to understand their evolution. In this review, we first recall the effect…

Astrophysics · Physics 2009-11-13 R. Hirschi , C. Chiappini , G. Meynet , A. Maeder , S. Ekstrom

Low-metallicity star formation poses a central problem of cosmology, as it determines the characteristic mass scale and distribution for the first and second generations of stars forming in our Universe. Here, we present a comprehensive…

Astrophysics of Galaxies · Physics 2014-07-02 Thomas Peters , Dominik R. G. Schleicher , Rowan J. Smith , Wolfram Schmidt , Ralf S. Klessen

Photoheating associated with reionization suppressed star formation in low-mass galaxies. Reionization was inhomogeneous, however, affecting different regions at different times. To establish the causal connection between reionization and…

Population III star formation during the dark ages shifted from minihalos (~10^6 Msun) cooled via molecular hydrogen to more massive halos (~10^8 Msun) cooled via Ly-alpha as Lyman-Werner backgrounds progressively quenched molecular…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Michele Trenti

An analysis of some properties of stellar models as a function of metallicity Z (and helium content Y) is presented, with special attention to those stars with metallicities higher than twice or three times solar. It is shown that the…

Astrophysics · Physics 2007-05-23 N. Mowlavi , G. Meynet , A. Maeder , D. Schaerer , C. Charbonnel

Stellar evolutionary tracks for $0.12 \le M/M_\odot \le 1.0$ have been computed for each of several variations in the abundances of C, N, and O, assuming mass-fraction helium abundances $Y = 0.25$ and $0.29$, and 11 metallicities in the…

Solar and Stellar Astrophysics · Physics 2022-11-30 Don A. VandenBerg

Observations of the explosions of Population III (Pop III) stars have the potential to teach us much about the formation and evolution of these zero-metallicity objects. To realize this potential, we must tie observed emission to an…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Chris L. Fryer , Daniel J. Whalen , Lucille Frey

Star-forming galaxies in the early universe provide us with perhaps the most natural way of explaining the reionization of the universe. Current observational results are sufficiently comprehensive, as to allow us to approximately calculate…

Astrophysics of Galaxies · Physics 2016-01-27 Rychard J. Bouwens

The abundance patterns of metal-poor stars provide us a wealth of chemical information about various stages of cosmic chemical evolution. In particular, these stars allow us to study the formation and evolution of the elements, and the…

Astrophysics of Galaxies · Physics 2015-03-17 Anna Frebel

We present a new set of zero metallicity models in the range 13-80 $\rm M_\odot$ together to the associated explosive nucleosynthesis. These models are fully homogeneous with the solar metallicity set we published in Limongi & Chieffi…

Solar and Stellar Astrophysics · Physics 2015-06-04 M. Limongi , A. Chieffi

We argue that extreme metal-poor stars show a high dispersion in metallicity, because their abundances are the outcome of very few supernova events. Abundance anomalies should appear because of the discrete range of progenitor masses. There…

Astrophysics · Physics 2009-10-28 Jean Audouze , Joseph Silk

We investigate the evolution of low-mass metal-free Population III stars. Emphasis is laid upon the question of internal and external sources for CNO-elements, which - if present in sufficient amounts in the hydrogen-burning regions - lead…

Astrophysics · Physics 2007-05-23 A. Weiss , S. Cassisi , H. Schlattl , M. Salaris

We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 < z < 6.0 (<z> = 4.8) in…

While most simulations of the epoch of reionization have focused on single-stellar populations in star-forming dwarf galaxies, products of binary evolution are expected to significantly contribute to emissions of hydrogen-ionizing photons.…

Astrophysics of Galaxies · Physics 2021-09-08 Elizabeth Berzin , Amy Secunda , Renyue Cen , Alexander Menegas , Ylva Götberg

Understanding the radii of massive stars throughout their evolution is important to answering numerous questions about stellar physics, from binary interactions on the main sequence to the pre-supernova radii. One important factor…

Solar and Stellar Astrophysics · Physics 2022-10-05 Chengcheng Xin , Mathieu Renzo , Brian D. Metzger

We present a new, on-the-fly photon flux and absorption tracer algorithm designed to directly measure the contribution of different source populations to the metagalactic UV background and to the ionisation fraction of gas in the Universe.…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Harley Katz , Taysun Kimm , Martin Haehnelt , Debora Sijacki , Joakim Rosdahl , Jeremy Blaizot