Publicación: Predicting the observability of population III stars with ELT-HARMONI via the helium 1640 Å emission line
Fecha
2021-01-08
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Editor
Oxford Academics: Oxford University Press
Resumen
Population III (Pop. III) stars, as of yet, have not been detected, however as we move into the era of extremely large telescopes this is likely to change. One likely tracer for Pop. III stars is the He IIλ1640 emission line, which will be detectable by the HARMONI spectrograph on the European Extremely Large Telescope (ELT) over a broad range of redshifts (2 ≤ z ≤ 14). By post-processing galaxies from the cosmological, AMR-hydrodynamical simulation NEWHORIZON with theoretical spectral energy distributions (SED) for Pop. III stars and radiative transfer (i.e. the Yggdrasil Models and CLOUDY look-up tables, respectively) we are able to compute the flux of He IIλ1640 for individual galaxies. From mock 10 h observations of these galaxies we show that HARMONI will be able to detect Pop. III stars in galaxies up to z ∼ 10 provided Pop. III stars have a top heavy initial mass function (IMF). Furthermore, we find that should Pop. III stars instead have an IMF similar to those of the Pop. I stars, the He IIλ1640 line would only be observable for galaxies with Pop. III stellar masses in excess of 107M⊙, average stellar age <1Myr at z = 4. Finally, we are able to determine the minimal intrinsic flux required for HARMONI to detect Pop. III stars in a galaxy up to z = 10.
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This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
Palabras clave
Stars, Population III, Galaxy: structure, Cosmology: observations
Citación
Monthly Notices of the Royal Astronomical Society 501(4): 5517–5537(2021)