THE EVOLUTION OF LYMAN LIMIT ABSORPTION SYSTEMS TO REDSHIFT SIX

By A. Songaila, L. Cowie. 2010

175 citations recorded by the source corpus.

We have measured the redshift evolution of the density of Lyman limit systems (LLSs) in the intergalactic medium over the redshift range 0 < z < 6. We have used two new quasar samples to (1) improve coverage at z ∼ 1, with GALEX grism spectrograph observations of 50 quasars with 0.8 < zem < 1.3, and (2) extend coverage to z ∼ 6, with Keck ESI spectra of 25 quasars with 4.17 < zem < 5.99. Using these samples together with published data, we find that the number density of LLS per unit redshift, n(z), can be well fit by a simple evolution of the form n(z) = n3.5[(1 + z)/4.5]γ with n3.5 = 2.80 ± 0.33 and γ = 1.94+0.36−0.32 for the entire range 0 < z < 6. We have also reanalyzed the evolution of damped Lyα systems (DLAs) in the redshift range 4 < z < 5 using our high-redshift quasar sample. We find a total of 17 DLAs and sub-DLAs, which we have analyzed in combination with published data. The DLAs with } 20.3$?> show the same redshift evolution as the LLS. When combined with previous results, our DLA sample is also consistent with a constant ΩDLA = 9 × 10−4 from z = 2 to z = 5. We have used the LLS number density evolution to compute the evolution in the mean free path (mfp) of ionizing photons. We find a smooth evolution to z ∼ 6, very similar in shape to that of Madau et al. but about a factor of two higher. Recent theoretical models roughly match to the z < 6 data but diverge from the measured power law at z>6 in different ways, cautioning against extrapolating the fit to the mfp outside the measured redshift range.

Subfields: Astronomy and Astrophysics, Instrumentation, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/159c8a5afecc2a888b2e14fcb7ff6c45c71fa86c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

In Statistical and Nonlinear Physics

Citations in the corpus

Inhomogeneous recombinations during cosmic reionization (2014, methodology): “Only the FULL run is consistent with observations at z ∼ 6, as well as the high redshift extrapolation of the empirically-calibrated formula provided in Songaila & Cowie (2010) λmfp = 50 ( 1 + z 4.5 )−4.44 pMpc , (18) which approximates the CDDF as a power law.”
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). V. Quasar Luminosity Function and Contribution to Cosmic Reionization at z = 6 (2018, methodology): “The effect of IGM absorption was modeled using the prescription of Worseck & Prochaska (2011) extended to higher redshifts with the data from Songaila & Cowie (2010), and was checked against the measurements of Songaila (2004) and Fan et al. (2006).”
CRITICAL STAR FORMATION RATES FOR REIONIZATION: FULL REIONIZATION OCCURS AT REDSHIFT z ≈ 7 (2012, methodology): “10−13 s−1, given in Table 3 of Haardt & Madau (2012), and the observed mean free path, λH i, at z = 5.5 may be closer to 6 proper Mpc (see Figure 10 of Songaila & Cowie 2010).”
The bolometric quasar luminosity function at z = 0–7 (2020, methodology): “(20) where we adopt αUV = 1.7 (Lusso et al. 2015) and ∆l912z=3.5 = 50 Mpc with a power-law index η = 4.44 for the redshift dependence of ∆l (Songaila & Cowie 2010).”
METALLICITY EVOLUTION OF DAMPED Lyα SYSTEMS OUT TO z ∼ 5 (2012, background): “…attenuates the quasar continuum at wavelengths shortward of Ly-α emission; i.e. at wavelengths where such DLAs would be located (Fan et al. 2006; Songaila & Cowie 2010) The new observations comprise a total of 6 nights (effectively 5 nights when considering the losses to poor weather) on ESI…”
Faint AGNs at z > 4 in the CANDELS GOODS-S field: looking for contributors to the reionization of the Universe (2015, background): “…than what required to keep the intergalactic medium highly ionized at z ∼ 6 despite the fact that each bright QSO is able to ionize its neighbourhood up to a distance of the order of e.g. 10 Mpc at z ∼ 5.5 (Prochaska, Worseck, & O’Meara (2009), Songaila & Cowie (2010), Worseck et al. (2014)).”
Evidence of patchy hydrogen reionization from an extreme Lyα trough below redshift six (2014, methodology): “We adopt c© 0000 RAS, MNRAS 000, 000–000 β = 1.3 (e.g., Songaila & Cowie 2010; Becker & Bolton 2013).”
New Measurements of the Ionizing Ultraviolet Background over 2 < z < 5 and Implications for Hydrogen Reionization (2013, methodology): “…to λ912(z) and nLLS(z) are shown as shaded regions in Figure 3.1 1 We note that despite the fact that we are consistent with the nLLS(z) values of Songaila & Cowie (2010), by design, and our best-fit value of βN is similar to the one used by those authors, c© 0000 RAS, MNRAS 000, 000–000 We…”
The ESO UVES advanced data products quasar sample: II. Cosmological evolution of the neutral gas mass density (2013, methodology): “The combined sample allows one to determine the number density of sub-DLAs and compare it with those for the DLAs and LLSs from the literature.”
The Neutral Hydrogen Cosmological Mass Density at z = 5 (2015, background): “Péroux et al. (2003), Guimarães et al. (2009) and Songaila & Cowie (2010) have all presented measurements of ΩHI at z > 4.5.”
Signatures of X-rays in the early Universe (2012, unknown): “We take Rmax = 40 Mpc, consistent with recent observations (e.g. Songaila & Cowie 2010) and theoretical estimates (e.g. McQuinn et al. 2011).”
THE z = 5 QUASAR LUMINOSITY FUNCTION FROM SDSS STRIPE 82 (2012, methodology): “We extend the model to higher redshifts by using the observed number densities of high column density systems from Songaila & Cowie (2010).”
Simulating cosmic reionization: how large a volume is large enough? (2013, background): “Another new element in the current radiative transfer simulations is that we also include an approximate treatment of the absorber systems which limit the mean free path of the ionizing photons during the late stages of reionization (Songaila & Cowie 2010).”
WHAT NEXT-GENERATION 21 cm POWER SPECTRUM MEASUREMENTS CAN TEACH US ABOUT THE EPOCH OF REIONIZATION (2013, methodology): “In this work, we explore a range of mean free paths from 3 to 80 Mpc, spanning the uncertainties in current measurements of the mean free path at z ∼ 6 (Songaila & Cowie 2010).”
NEW CONSTRAINTS ON COSMIC REIONIZATION FROM THE 2012 HUBBLE ULTRA DEEP FIELD CAMPAIGN (2013, background): “…redshiftsz = [4.0,4.2,5.0] inferred by Kuhlen & Faucher-Giguère (2012) from measurements by Faucher-Giguère et al. (2008), Prochaska et al. (2009), and Songaila & Cowie (2010), this maximum likelihood model with evolving fescrecovers similar values (ṅ = [3.3,3.5,4.7]× 1050 s−1 Mpc−3 at z =…”
Ingredients for 21 cm Intensity Mapping (2018, methodology): “In this plot we also indicate measurements from different observations (Zwaan & Prochaska 2006; Rao et al. 2006; Lah et al. 2007; Songaila & Cowie 2010; Martin et al. 2010; Noterdaeme et al. 2012; Braun 2012; Rhee et al. 2013; Delhaize et al. 2013; Crighton et al. 2015).”
The Giant Gemini GMOS survey of zem > 4.4 quasars – I. Measuring the mean free path across cosmic time (2014, methodology): “At the same redshift, the power-law fit to the LLS incidence by Songaila & Cowie (2010) yields λ912mfp 7 Mpc, but with an estimated uncertainty of ∼30 per cent due to the poorly constrained shape of f (NH I, z) at high redshift.”