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Table · dataset · 2020

LARS XI. Turbulence Driven Lyman Alpha Escape

Listed in IVOA Registry (Virtual Observatory)

We study the global dust and (molecular) gas content in the Lyman Alpha Reference Sample (LARS), i.e. 14 local star-forming galaxies.

Description

We characterize their interstellar medium and relate newly derived properties to quantities relevant for Ly{alpha} escape. We observed LARS galaxies with Herschel/PACS, SOFIA/FIFI-LS, the IRAM 30m telescope and APEX, targeting far-infrared (FIR) continuum and emission lines of [CII]158um, [OI]63um, [OIII]88um and low-J CO lines.

Using Bayesian methods we derive dust model parameters and estimate total gas masses for all LARS galaxies, taking into account a metallicity-dependent gas-to-dust ratio. Star formation rates were estimated from FIR, [CII]158um and [OI]63um luminosities. LARS covers a wide dynamic range in the derived properties, with FIR-based star formation rates from ~0.5-100M_{sun}/yr, gas fractions between ~15-80% and gas depletion times ranging from a few hundred Myr up to more than 10Gyr.

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The distribution of LARS galaxies in the {SIGMA}_gas_ vs. {SIGMA}_SFR_ (Kennicutt-Schmidt plane) is thus quite heterogeneous. However, we find that LARS galaxies with the longest gas depletion times, i.e. relatively high gas surface densities ({SIGMA}_gas_) and low star formation rate densities ({SIGMA}_SFR_ have by far the highest Ly{alpha} escape fraction. A strong [Math Processing Error]linear relation is found between Ly{alpha} escape fraction and the total gas (HI+H_2_) depletion time.

We argue that the Ly{alpha} escape in those galaxies is driven by turbulence in the star-forming gas that shifts the Ly{alpha} photons out of resonance close to the places where they originate. We further report on an extreme [CII]158um excess in LARS 5, corresponding to ~14+/-3% of the FIR luminosity, i.e. the most extreme [CII]-to-FIR ratio observed in a non-AGN galaxy to date.

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Catalogue records · 2

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Stated by source
Infrared · Millimeter
Provenance · 1 source records, 9 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/a+a/644/a1013 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:infraredsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:millimetersource · IVOA Registryconnector:ivoa_registry@1.0.0
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0