Low-redshift Lyman continuum leaking galaxies with high [O III]/[O II] ratios
- We present observations with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope of five star-forming galaxies at redshifts z in the range 0.2993-0.4317 and with high emission-line flux ratios O-32 = [O III]lambda 5007/[O II]lambda 3727 similar to 8-27 aiming to detect the Lyman continuum (LyC) emission. We detect LyC emission in all galaxies with the escape fractions f(esc)(LyC) in a range of 2-72 per cent. A narrow Ly alpha emission line with two peaks in four galaxies and with three peaks in one object is seen in medium-resolution COS spectra with a velocity separation between the peaks V-sep varying from similar to 153 to similar to 345 km s(-1). We find a general increase of the LyC escape fraction with increasing O-32 and decreasing stellar mass M-star, but with a large scatter of f(esc)(LyC). A tight anticorrelation is found between f(esc)(LyC) and V-sep making V-sep a good parameter for the indirect determination of the LyC escape fraction. We argue that one possible source driving the escape of ionizingWe present observations with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope of five star-forming galaxies at redshifts z in the range 0.2993-0.4317 and with high emission-line flux ratios O-32 = [O III]lambda 5007/[O II]lambda 3727 similar to 8-27 aiming to detect the Lyman continuum (LyC) emission. We detect LyC emission in all galaxies with the escape fractions f(esc)(LyC) in a range of 2-72 per cent. A narrow Ly alpha emission line with two peaks in four galaxies and with three peaks in one object is seen in medium-resolution COS spectra with a velocity separation between the peaks V-sep varying from similar to 153 to similar to 345 km s(-1). We find a general increase of the LyC escape fraction with increasing O-32 and decreasing stellar mass M-star, but with a large scatter of f(esc)(LyC). A tight anticorrelation is found between f(esc)(LyC) and V-sep making V-sep a good parameter for the indirect determination of the LyC escape fraction. We argue that one possible source driving the escape of ionizing radiation is stellar winds and radiation from hot massive stars.…
| Author details: | Y. I. Izotov, Gábor WorseckORCiD, Daniel SchaererORCiD, N. G. Guseva, T. X. Thuan, K. J. Fricke, Anne Verhamme, I. Orlitova |
|---|---|
| DOI: | https://doi.org/10.1093/mnras/sty1378 |
| ISSN: | 0035-8711 |
| ISSN: | 1365-2966 |
| Title of parent work (English): | Monthly notices of the Royal Astronomical Society |
| Publisher: | Oxford Univ. Press |
| Place of publishing: | Oxford |
| Publication type: | Article |
| Language: | English |
| Date of first publication: | 2018/05/25 |
| Publication year: | 2018 |
| Release date: | 2021/10/27 |
| Tag: | dark ages, reionization, first stars; galaxies: ISM; galaxies: abundances; galaxies: dwarf; galaxies: fundamental parameters; galaxies: starburst |
| Volume: | 478 |
| Issue: | 4 |
| Number of pages: | 15 |
| First page: | 4851 |
| Last Page: | 4865 |
| Funding institution: | NASANational Aeronautics & Space Administration (NASA) [NAS 5-26555]; NASA through the Space Telescope Science InstituteSpace Telescope Science Institute [HST-GO-14635.002-A]; National Academy of Sciences of Ukraine [0116U003191]; Program of Fundamental Research of the Department of Physics and Astronomy [0117U000240]; Deutsches Zentrum fur Luft-und Raumfahrt (DLR)Helmholtz AssociationGerman Aerospace Centre (DLR) [50OR1720]; Czech National Foundation [GACR 14-20666P, 17-06217Y]; Alfred P. Sloan FoundationAlfred P. Sloan Foundation; National Science FoundationNational Science Foundation (NSF); U.S. Department of Energy Office of ScienceUnited States Department of Energy (DOE) |
| Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
| DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
| Peer review: | Referiert |
| Publishing method: | Open Access / Bronze Open-Access |
