%0 Generic %1 izotov2016detection %A Izotov, Y. I. %A Schaerer, D. %A Thuan, T. X. %A Worseck, G. %A Orlitova, I. %A Verhamme, A. %D 2016 %K compact escape formation fraction low-z star %T Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies %U http://arxiv.org/abs/1605.05160 %X Following our first detection reported in Izotov et al. (2016), we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST). These galaxies, at redshifts of z~0.3, are characterized by high emission-line flux ratios OIII5007/OII3727 > 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ~6%-13%, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Lyalpha emission lines are detected in the spectra of all four galaxies, compatible with predictions for Lyman continuum leakers. We find escape fractions of Lyalpha, fesc(Lyalpha) ~60%-90%, among the highest known for Lyalpha emitters (LAEs). Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the center and exponential discs in the outskirts with disc scale lengths alpha in the range ~0.6-1.4 kpc. Our galaxies are characterized by low metallicity, ~1/8-1/5 solar, low stellar mass ~(0.2 - 4)e9 Msun, high star formation rates SFR~14-36 Msun/yr, and high SFR densities Sigma~2-35 Msun/yr/kpc^2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al. (2016), reveal that a selection for compact star-forming galaxies showing high OIII5007/OII3727 ratios appears to pick up very efficiently sources with escaping Lyman continuum radiation: all five of our selected galaxies are LyC leakers.

@misc{izotov2016detection, abstract = {Following our first detection reported in Izotov et al. (2016), we present the detection of Lyman continuum (LyC) radiation of four other compact star-forming galaxies observed with the Cosmic Origins Spectrograph (COS) onboard the Hubble Space Telescope (HST). These galaxies, at redshifts of z~0.3, are characterized by high emission-line flux ratios [OIII]5007/[OII]3727 > 5. The escape fractions of the LyC radiation fesc(LyC) in these galaxies are in the range of ~6%-13%, the highest values found so far in low-redshift star-forming galaxies. Narrow double-peaked Lyalpha emission lines are detected in the spectra of all four galaxies, compatible with predictions for Lyman continuum leakers. We find escape fractions of Lyalpha, fesc(Lyalpha) ~60%-90%, among the highest known for Lyalpha emitters (LAEs). Surface brightness profiles produced from the COS acquisition images reveal bright star-forming regions in the center and exponential discs in the outskirts with disc scale lengths alpha in the range ~0.6-1.4 kpc. Our galaxies are characterized by low metallicity, ~1/8-1/5 solar, low stellar mass ~(0.2 - 4)e9 Msun, high star formation rates SFR~14-36 Msun/yr, and high SFR densities Sigma~2-35 Msun/yr/kpc^2. These properties are comparable to those of high-redshift star-forming galaxies. Finally, our observations, combined with our first detection reported in Izotov et al. (2016), reveal that a selection for compact star-forming galaxies showing high [OIII]5007/[OII]3727 ratios appears to pick up very efficiently sources with escaping Lyman continuum radiation: all five of our selected galaxies are LyC leakers.}, added-at = {2016-05-18T10:18:15.000+0200}, author = {Izotov, Y. I. and Schaerer, D. and Thuan, T. X. and Worseck, G. and Orlitova, I. and Verhamme, A.}, biburl = {https://www.bibsonomy.org/bibtex/21192dfb858d37d222e464ebaf37116ec/miki}, description = {[1605.05160] Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies}, interhash = {ecb167a088ef4a9587f43b5c4b04e0e8}, intrahash = {1192dfb858d37d222e464ebaf37116ec}, keywords = {compact escape formation fraction low-z star}, note = {cite arxiv:1605.05160Comment: 21 pages, 14 figures, accepted for publication in MNRAS}, timestamp = {2016-05-18T10:18:15.000+0200}, title = {Detection of high Lyman continuum leakage from four low-redshift compact star-forming galaxies}, url = {http://arxiv.org/abs/1605.05160}, year = 2016 }