Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey

Autor: Eros Vanzella, Lucia Guaita, Laura Pentericci, Marusa Bradac, Kasper B. Schmidt, Tucker Jones, Ricardo Amorín, Alaina Henry, Adriano Fontana, Tommaso Treu, Austin Hoag, Michele Trenti, Matthew A. Malkan, Charlotte Mason, Louis E. Abramson
Rok vydání: 2019
Předmět:
Cosmology and Nongalactic Astrophysics (astro-ph.CO)
astro-ph.GA
Astrophysics::High Energy Astrophysical Phenomena
first stars
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
Astronomy & Astrophysics
01 natural sciences
0103 physical sciences
Emission spectrum
dark ages
010303 astronomy & astrophysics
Reionization
evolution [galaxies]
Astrophysics::Galaxy Astrophysics
Galaxy cluster
Photometric redshift
Luminosity function (astronomy)
Physics
010308 nuclear & particles physics
Astronomy and Astrophysics
Astrophysics - Astrophysics of Galaxies
Redshift
Galaxy
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
astro-ph.CO
reionization
intergalactic medium
Lyman-break galaxy
high-redshift [galaxies]
Astronomical and Space Sciences
Astrophysics - Cosmology and Nongalactic Astrophysics
Zdroj: Monthly Notices of the Royal Astronomical Society, vol 485, iss 3
Mason, Charlotte A; Fontana, Adriano; Treu, Tommaso; Schmidt, Kasper B; Hoag, Austin; Abramson, Louis; et al.(2019). Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey. Monthly Notices of the Royal Astronomical Society, 485(3), 3947-3969. doi: 10.1093/mnras/stz632. UC Davis: Retrieved from: http://www.escholarship.org/uc/item/58n3m7q1
ISSN: 1365-2966
0035-8711
DOI: 10.1093/mnras/stz632
Popis: Detections and non-detections of Lyman alpha (Ly$\alpha$) emission from $z>6$ galaxies ($ 7, where Ly$\alpha$ redshifts to near infra-red wavelengths. Here we present a search for z > 7.2 Ly$\alpha$ emission in 53 intrinsically faint Lyman Break Galaxy candidates, gravitationally lensed by massive galaxy clusters, in the KMOS Lens-Amplified Spectroscopic Survey (KLASS). With integration times of ~7-10 hours, we detect no Ly$\alpha$ emission with S/N>5 in our sample. We determine our observations to be 80% complete for 5$\sigma$ spatially and spectrally unresolved emission lines with integrated line flux $>5.7\times10^{-18}$ erg s$^{-1}$ cm$^{-2}$. We define a photometrically selected sub-sample of 29 targets at $z=7.9\pm0.6$, with a median 5$\sigma$ Ly$\alpha$ EW limit of 58A. We perform a Bayesian inference of the average intergalactic medium (IGM) neutral hydrogen fraction using their spectra. Our inference accounts for the wavelength sensitivity and incomplete redshift coverage of our observations, and the photometric redshift probability distribution of each target. These observations, combined with samples from the literature, enable us to place a lower limit on the average IGM neutral hydrogen fraction of $> 0.76 \; (68\%), \; > 0.46 \; (95\%)$ at z ~ 8, providing further evidence of rapid reionization at z~6-8. We show that this is consistent with reionization history models extending the galaxy luminosity function to $M_\textrm{UV} \lesssim -12$, with low ionizing photon escape fractions, $f_\textrm{esc} \lesssim 15\%$.
Comment: Accepted for publication in MNRAS
Databáze: OpenAIRE
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