Sökning: "Reionization"

Visar resultat 1 - 5 av 14 avhandlingar innehållade ordet Reionization.

  1. 1. Galaxies in the epoch of reionization : Investigating the high-redshift galaxy population through simulations and observations

    Författare :Christian Binggeli; Erik Zackrisson; Sofia Ramstedt; Martin Sahlén; Stephen Wilkins; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxies: high-redshift; galaxies: ISM; galaxies: evolution; reionization; Lyman continuum; Astronomy; Astronomi;

    Sammanfattning : The cosmic reionization is the last major gas phase transition in cosmic history, yet it remains poorly understood. Current constraints indicate that early star-forming galaxies drove the reionization process through producing and releasing large numbers of ionizing photons into the intergalactic medium. LÄS MER

  2. 2. Tomographic studies of the 21-cm signal during reionization : Going beyond the power spectrum

    Författare :Sambit K. Giri; Garrelt Mellema; Benoît Semelin; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; reionization; non-gaussianity; first stars; image processing; Astronomy; astronomi;

    Sammanfattning : The formation of the first luminous sources in the Universe, such as the first generation of stars and accreting black holes, led to the ionization of hydrogen gas present in the intergalactic medium (IGM). This period in which the Universe transitioned from a cold and neutral state to a predominantly hot and ionized state is known as the Epoch of Reionization (EoR). LÄS MER

  3. 3. Simulations of Cosmic Reionization : Shapes & Sizes of H II regions around Galaxies and Quasars

    Författare :Martina M. Friedrich; Garrelt Mellema; Jonathan Pritchard; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

    Sammanfattning : After the era of recombination, roughly 360 000 years after the big bang (redshift 1100), the universe was neutral, continued to expand and eventually the first gravitationally collapsed structures capable of forming stars, formed. Observations show that approximately 1 billion years later (redshift 6), the Universe had become highly ionized. LÄS MER

  4. 4. Simulating observational probes of reionization

    Författare :Hannes Jensen; Garrelt Mellema; Adam Lidz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; astronomi;

    Sammanfattning : The time in the history of the Universe when the first stars and galaxies formed and ionized the gas in the intergalactic medium is known as the Epoch of Reionization. This transformative time period, which took place within the first billion years after the Big Bang, is still relatively unexplored due to the significant difficulties associated with observing so far back in time. LÄS MER

  5. 5. Molecular gas and ionizing radiation in star-forming galaxies

    Författare :Johannes Puschnig; Matthew Hayes; Göran Östlin; Amélie Saintonge; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrophysics; galaxies; star formation; starburst; interstellar medium; Lyman continuum; Lyman alpha; reionization; gravitational instability; molecular gas; clump formation; Astronomy; astronomi;

    Sammanfattning : In cosmic history, some of the major changes such as reionization were driven by baryons (i.e. the stars and gas in galaxies), despite the fact that they contribute only few percent to the total mass-energy budget in the Universe. LÄS MER