Overview of Flaw Assessment Methods in the RSE-M Code

Delliou, Patrick Le; Sermage, Jean-Philippe; Barthelet, B.

doi:10.1115/pvp2004-2728

Cited by 10 publications

(10 citation statements)

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“…This is at the lower end of being consistent with our z = 3 measurements, and should the same escape fraction hold at z = 0.3, would also be consistent with our estimates in the nearby universe. However, the Le Delliou et al (2005) escape fraction is highly inconsistent with our estimates at higher redshift. These semi-analytical models, using the prescription of Baugh et al (2005), categorized star-formation as occurring in two discrete modes, with a normal Salpeter IMF (α = −1.35) assigned to quiescent star-formation and a flat IMF (α = 0) for bursting systems.…”

Section: Comparison With the Literaturecontrasting

confidence: 99%

“…Adopting a similar method of LF scaling by luminosity, Le Delliou et al (2005) found that an escape fraction of 2 % was sufficient to match observed Lyα LFs with their predictions based upon semi-analytical models between z = 2 and 6, with the same machinery able to predict the clustering properties of Lyα emitters (Orsi et al 2008). This is at the lower end of being consistent with our z = 3 measurements, and should the same escape fraction hold at z = 0.3, would also be consistent with our estimates in the nearby universe.…”

Section: Comparison With the Literaturementioning

confidence: 99%

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ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES

Hayes

Schaerer

Östlin

et al. 2011

ApJ

271

342

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The Lyα emission line has been proven a powerful tool by which to study evolving galaxies at the highest redshifts. However, in order to use Lyα as a physical probe of galaxies, it becomes vital to know the Lyα escape fraction (f Lyα esc ). Unfortunately, due to the resonant nature of Lyα, f Lyα esc may vary unpredictably and requires empirical measurement. Here we compile Lyα luminosity functions between redshift z=0 and 8 and, combined with Hα and ultraviolet data, assess how f Lyα esc evolves with redshift. We find a strong upwards evolution in f Lyα esc over the range z = 0.3 − 6, which is well-fit by the power-law f LyαThis predicts that f Lyα esc should reach unity at z = 11.1. By comparing f Lyα esc and E B−V in individual galaxies we derive an empirical relationship between f Lyα esc and E B−V , which includes resonance scattering and can explain the redshift evolution of f Lyα esc between z = 0 and 6 purely as a function of the evolution in the dust content of galaxies. Beyond z ≈ 6.5, f Lyα esc drops more substantially; an effect attributed to either ionizing photon leakage, or an increase in the neutral gas fraction of the intergalactic medium. While distinguishing between those two scenarios may be extremely challenging, by framing the problem this way we remove the uncertainty of the halo mass from Lyα-based tests of reionization. We finally derive a new method by which to estimate the dust content of galaxies based purely upon the observed Lyα and UV LFs. These data are characterized by an exponential with an e-folding redshift of ≈ 3.5.

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Section: Comparison With the Literaturecontrasting

confidence: 99%

Section: Comparison With the Literaturementioning

confidence: 99%

ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES

Hayes

Schaerer

Östlin

et al. 2011

ApJ

271

342

View full text Add to dashboard Cite

show abstract

“…Since the interaction between dark energy and dark matter modifies the growth rate of the density perturbation of dark matter compared with baryon which is not expected to have direct interaction with dark energy, the overdensity of dark matter and baryon collapse with different rate in coupled dark energy models. As a result, the ratio of baryon density to dark matter density in the clusters is influenced by the interaction between dark energy and dark matter [58,59]. However, to avoid the complexities of the collapsing processes, we do not consider this influence and ignore baryon in our consideration similar to the analysis in [27,53].…”

Section: Evolution Equationsmentioning

confidence: 99%

Spherical collapse and cluster number counts in dark energy models disformally coupled to dark matter

2018

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We investigate the effects of a disformal coupling between dark energy and dark matter in the predictions of the spherical collapse and its signatures in galaxy cluster number counts.We find that the disformal coupling has no significant effects on spherical collapse at high redshifts, and in particular during matter domination epoch. However, at lower redshifts, the extrapolated linear density contrast at collapse close to redshift z 1 and overdensity at virialization can be strongly suppressed by a disformal coupling between dark energy and dark matter. We also find that disformal coupling can have different imprints on cluster number counts compared with conformal coupling, such that the disformal coupling can strongly suppress the predicted number of clusters per redshift interval at z > 0.1 while enhance the number of cluster at z < 0.05. Using the specifications of eROSITA survey, we find that the disformal coupling between dark energy and dark matter can be tightly constrained by cluster number counts.

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“…prior to processing of the line through the IGM) is the same at z = 6.5 as at z = 5.7. More realistic models, based on the hierarchical growth of structures, combined with Lyman α line processing by gas and dust interior to the galaxies, predict that the number of emitters were smaller at earlier epochs (Haiman and Spaans 1999; Le Delliou et al 2004), which would strengthen the limits on x HI below.…”

Section: An Upper Limit From the Abundance Of Lyman α Emittersmentioning

confidence: 99%

Finding the First Generation of Stars and Black Holes

Haiman¹

2005

Prog. Theor. Phys. Suppl.

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The first stars and black holes that formed in the Universe are likely too faint for a direct detection. However, by ionizing most of the intergalactic medium (IGM), they left an indirect clue that reveals their existence. We discuss currently available observational constraints on the reionization history of IGM, and the extent to which accreting black holes (BHs) and stars can help account for these observations. We argue, based on the combined statistics of Lyman α and β absorption in quasar spectra, that the IGM contains a significant amount of neutral hydrogen with n HI/nH ∼ > 0.1. On the other hand, we argue, based on the lack of a strong evolution in the observed abundance of Lyman α emitting galaxies beyond z ∼ 5.5, that the mean neutral hydrogen fraction cannot exceed n HI/nH ≈ 0.3 at the same redshift. We conclude that the IGM is experiencing rapid ionization at redshift z ∼ 6.We find that quasar BHs, including faint ones that are individually below the detection thresholds of existing optical and X-ray surveys, are unlikely to drive the evolution of the neutral fraction around this epoch, because they would over-produce the present-day soft X-ray background. On the other hand, the seeds of the z ∼ 6 quasar BHs likely appeared at much earlier epochs (z ∼ 20), and produced hard ionizing radiation by accretion. These early BHs are promising candidates to account for the high redshift (z ∼ 15) ionization implied by the recent cosmic microwave anisotropy data from WMAP.Using a model for the growth of BHs by accretion and mergers in a hierarchical cosmology, we suggest that the early growth of quasars must include a super-Eddington growth phase, and that, although not yet optically identified, the FIRST radio survey may have already detected several thousand > 10 8 M BHs at z > 6. §1. Black holes, stars, and reionizationThe recent discovery 5), 13), 66) of the Gunn-Peterson (GP) troughs in the spectra of z > 6 quasars in the Sloan Digital Sky Survey (SDSS), has suggested that the end of the reionization process occurs at a redshift near z ∼ 6. On the other hand, the high electron scattering optical depth, τ e = 0.17 ± 0.04, measured recently by the Wilkinson Microwave Anisotropy Probe (WMAP) experiment (Spergel et al. 2003) suggests that ionizing sources were abundant at a much higher redshift, z ∼ 15. These data imply that the reionization process is extended and complex, and is probably driven by more than one population of ionizing sources (see, e.g., Haiman 2003 19) for a recent review).The exact nature of the ionizing sources remains unknown. Natural candidates to account for the onset of reionization at z ∼ 15 are massive, metal-free stars that form in the shallow potential wells of the first collapsed dark matter halos. 6), 24), 67) The completion of reionization at z ∼ 6 could then be accounted for by a normal population of less massive stars that form from the metal-enriched gas in more massive dark matter halos present at z ∼ 6.The most natural alternative cause for reionization is the ionizing rad...

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Overview of Flaw Assessment Methods in the RSE-M Code

Cited by 10 publications

References 0 publications

ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES

ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES

Spherical collapse and cluster number counts in dark energy models disformally coupled to dark matter

Finding the First Generation of Stars and Black Holes

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