Search: onr:"swepub:oai:DiVA.org:su-203961" >
The synchrony of pr...
The synchrony of production and escape : half the bright Lyα emitters at z ≈ 2 have Lyman continuum escape fractions ≈50 per cent
-
Naidu, Rohan P. (author)
-
Matthee, Jorryt (author)
-
Oesch, Pascal A. (author)
-
show more...
-
Conroy, Charlie (author)
-
Sobral, David (author)
-
Pezzulli, Gabriele (author)
-
- Hayes, Matthew J. (author)
- Stockholms universitet,Institutionen för astronomi,Oskar Klein-centrum för kosmopartikelfysik (OKC)
-
Erb, Dawn (author)
-
Amorín, Ricardo (author)
-
Gronke, Max (author)
-
Schaerer, Daniel (author)
-
Tacchella, Sandro (author)
-
Kerutt, Josephine (author)
-
Paulino-Afonso, Ana (author)
-
Calhau, João (author)
-
Llerena, Mario (author)
-
Rottgering, Huub (author)
-
show less...
-
(creator_code:org_t)
- 2021-12-11
- 2022
- English.
-
In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 510:3, s. 4582-4607
- Related links:
-
https://scholarlypub...
-
show more...
-
https://urn.kb.se/re...
-
https://doi.org/10.1...
-
show less...
Abstract
Subject headings
Close
- The ionizing photon escape fraction [Lyman continuum (LyC) fesc] of star-forming galaxies is the single greatest unknown in the reionization budget. Stochastic sightline effects prohibit the direct separation of LyC leakers from non-leakers at significant redshifts. Here we circumvent this uncertainty by inferring fesc using resolved (R > 4000) Lyman α (Lyα) profiles from the X-SHOOTER Lyα survey at z = 2 (XLS-z2). With empirically motivated criteria, we use Lyα profiles to select leakers (fesc>20 per centfesc>20 per cent) and non-leakers (fesc<5 per centfesc<5 per cent) from a representative sample of >0.2L* Lyman α emitters (LAEs). We use median stacked spectra of these subsets over λrest ≈ 1000–8000 Å to investigate the conditions for LyC fesc. Our stacks show similar mass, metallicity, MUV, and βUV. We find the following differences between leakers versus non-leakers: (i) strong nebular C IV and He II emission versus non-detections; (ii) [O III]/[O II] ≈ 8.5 versus ≈3; (iii) Hα/Hβ indicating no dust versus E(B − V) ≈ 0.3; (iv) Mg II emission close to the systemic velocity versus redshifted, optically thick Mg II; and (v) Lyα fesc of ≈50 per cent≈50 per cent versus ≈10 per cent≈10 per cent. The extreme equivalent widths (EWs) in leakers ([O III]+Hβ≈1100Hβ≈1100 Å rest frame) constrain the characteristic time-scale of LyC escape to ≈3–10 Myr bursts when short-lived stars with the hardest ionizing spectra shine. The defining traits of leakers – extremely ionizing stellar populations, low column densities, a dust-free, high-ionization state interstellar medium (ISM) – occur simultaneously in the fesc>20 per centfesc>20 per cent stack, suggesting they are causally connected, and motivating why indicators like [O III]/[O II] may suffice to constrain fesc at z > 6 with the James Webb Space Telescope (JWST). The leakers comprise half of our sample, have a median LyCfesc≈50 per centfesc≈50 per cent (conservative range: 20−55 per cent20−55 per cent), and an ionizing production efficiency log(ξion/Hz erg−1)≈25.9log(ξion/Hz erg−1)≈25.9 (conservative range: 25.7–25.9). These results show LAEs – the type of galaxies rare at z ≈ 2, but that become the norm at higher redshift – are highly efficient ionizers, with extreme ξion and prolific fesc occurring in sync.
Subject headings
- NATURVETENSKAP -- Fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences (hsv//eng)
Keyword
- galaxies: evolution
- galaxies: high-redshift
- intergalactic medium
- dark ages
- reionization
- first stars
- cosmology: observations
- ultraviolet: galaxies
Publication and Content Type
- ref (subject category)
- art (subject category)
Find in a library
To the university's database
- By the author/editor
-
Naidu, Rohan P.
-
Matthee, Jorryt
-
Oesch, Pascal A.
-
Conroy, Charlie
-
Sobral, David
-
Pezzulli, Gabrie ...
-
show more...
-
Hayes, Matthew J ...
-
Erb, Dawn
-
Amorín, Ricardo
-
Gronke, Max
-
Schaerer, Daniel
-
Tacchella, Sandr ...
-
Kerutt, Josephin ...
-
Paulino-Afonso, ...
-
Calhau, João
-
Llerena, Mario
-
Rottgering, Huub
-
show less...
- About the subject
-
- NATURAL SCIENCES
-
NATURAL SCIENCES
-
and Physical Science ...
- Articles in the publication
-
Monthly notices ...
- By the university
-
Stockholm University