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Related papers: Ionizing Photon Escape Fractions from High Redshif…

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We couple the DELPHI framework for galaxy formation with a model for the escape of ionizing photons to study both its variability with galaxy assembly and the resulting key reionization sources. In this model, leakage either occurs through…

Astrophysics of Galaxies · Physics 2023-06-28 Jonas Bremer , Pratika Dayal

We study the escape of Lyman continuum radiation from the disks of dwarf starburst galaxies, with and without supershells, by solving the radiation transfer problem of stellar radiation through them. We model disks with Md=10^8-10Msun, with…

Astrophysics · Physics 2009-11-07 Akimi Fujita , Crystal Martin , Mordecai-Mark Mac Low , Tom Abel

The contribution of stars in galaxies to cosmic reionisation depends on the star formation history in the Universe, the abundance of galaxies during reionisation, the escape fraction of ionising photons and the clumping factor of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jan-Pieter Paardekooper , Sadegh Khochfar , Claudio Dalla Vecchia

The reionization epoch concludes when ionizing photons reach every corner of the Universe. Reionization has generally been assumed to be limited primarily by the rate at which galaxies produce ionizing photons, but the recent measurement of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 Frederick B. Davies , Sarah E. I. Bosman , Steven R. Furlanetto , George D. Becker , Anson D'Aloisio

We demonstrate a new method for measuring the escape fraction of ionizing photons using Hubble Space Telescope imaging of resolved stars in NGC 4214, a local analog of high-redshift starburst galaxies that are thought to be responsible for…

Starlight from galaxies plays a pivotal role throughout the process of cosmic reionisation. We present the statistics of dwarf galaxy properties at z > 7 in haloes with masses up to 10^9 solar masses, using a cosmological radiation…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-08 John H. Wise , Vasiliy G. Demchenko , Martin T. Halicek , Michael L. Norman , Matthew J. Turk , Tom Abel , Britton D. Smith

In this paper we calculate the escape fraction ($f_{\rm esc}$) of ionizing photons from starburst galaxies. Using 2-D axisymmetric hydrodynamic simulations, we study superbubbles created by overlapping supernovae in OB associations. We…

Astrophysics of Galaxies · Physics 2015-05-14 Arpita Roy , Biman B. Nath , Prateek Sharma

Some Lyman continuum photons are likely to escape from most galaxies, and these can play an important role in ionizing gas around and between galaxies, including gas that gives rise to Lyman alpha absorption. Thus the gas surrounding…

The UV photon escape fraction from molecular clouds is a key parameter for understanding the ionization of the Interstellar Medium (ISM), and extragalactic processes, such as cosmic reionization. We present the ionizing photon flux and the…

Astrophysics of Galaxies · Physics 2017-01-12 Corey S. Howard , Ralph E. Pudritz , Ralf S. Klessen

Observations of the Lyman-alpha forest and of high-redshift galaxies at z~5-10 imply that there were just enough photons to maintain the universe in an ionized state at z~5-6, indicating a "photon-starved" end to reionization. The ionizing…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Marcelo A. Alvarez , Kristian Finlator , Michele Trenti

We present the escape fraction of hydrogen ionizing photons (f_esc) from a sample of 34 high-resolution cosmological zoom-in simulations of galaxies at z>5 in the Feedback in Realistic Environments project, post-processed with a Monte Carlo…

The Durham GALFORM semi-analytical galaxy formation model has been shown to reproduce the observed rest-frame 1500\AA\ luminosity function of galaxies well over the whole redshift range z=5-10. We show that in this model, this galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Milan Raičević , Tom Theuns , Cedric Lacey

In order to assess the contribution of Lyman break galaxies (LBGs) and Lyman alpha emitters (LAEs) at redshifts 3<z<7 to the ionization of intergalactic medium (IGM), we investigate the escape fractions of ionizing photons from…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Hidenobu Yajima , Masayuki Umemura , Masao Mori , Taishi Nakamoto

The Magellanic Stream and several high velocity clouds have now been detected in optical line emission. The observed emission measures and kinematics are most plausibly explained by photoionization due to hot, young stars in the Galactic…

Astrophysics · Physics 2009-10-31 J. Bland-Hawthorn , P. R. Maloney

Approximately 30% of all massive stars in the Galaxy are runaways with velocities exceeding 30 km/s. Their high speeds allow them to travel ~0.1-1 kpc away from their birth place before they explode at the end of their several Myr…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Charlie Conroy , Kaitlin Kratter

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

The Lyman continuum (LyC) flux escaping from high-z galaxies into the IGM is a fundamental quantity to understand the physical processes involved in the reionization epoch. We have investigated a sample of star-forming galaxies at z~3.3 in…

During the period of reionization the Universe was filled with a cosmological background of ionizing radiation. By that time a significant fraction of the cosmic gas had already been incorporated into collapsed galactic halos with virial…

Astrophysics · Physics 2009-10-31 Rennan Barkana , Abraham Loeb

We measure escape fractions, $f_{\rm esc}$, of ionizing radiation from galaxies in the SPHINX suite of cosmological radiation-hydrodynamical simulations of reionization, resolving halos with $M_{\rm vir} \gtrapprox 7.5 \times 10^7 \…

The escape of ultraviolet photons from the densest regions of the interstellar medium (ISM) --- Giant Molecular Clouds (GMCs) --- is a poorly constrained parameter which is vital to understanding the ionization of the ISM and the…

Astrophysics of Galaxies · Physics 2018-02-21 Corey S. Howard , Ralph E. Pudritz , Bill E. Harris , Ralf S. Klessen