%0 Generic %1 bian2017lyman %A Bian, Fuyan %A Fan, Xiaohui %A McGreer, Ian %A Zheng, Cai %A Jiang, Linhua %D 2017 %K escape fraction galaxy low mass %T High Lyman Continuum Escape Fraction in a Lensed Young Compact Dwarf Galaxy at $z=2.5$ %U http://arxiv.org/abs/1702.06540 %X We present the HST WFC3/F275W UV imaging observations of A2218-Flanking, a lensed compact dwarf galaxy at redshift $z\approx2.5$. The stellar mass of A2218-Flanking is $łog(M/M_ødot=9.14$ and SFR is 12.5~$M_ødot$~yr$^-1$ after correcting the magnification. This galaxy has a young galaxy age of 127~Myr and a compact galaxy size of $r_1/2=2.4$~kpc. The HST UV imaging observations cover the rest-frame Lyman continuum (LyC) emission ($\sim800$\AA) from A2218-Flanking. We firmly detect ($14\sigma$) the LyC emission in A2218-Flanking in the F275W image. Together with the HST F606W images, we find that the absolute escape fraction of LyC is $f_\rm abs,esc>28-57\%$ based on the flux density ratio between 1700\AA and 800\AA ($f_1700/f_800$). The morphology of the LyC emission in the F275W images is extended and well follows the morphology of the UV continuum morphology in the F606W images, suggesting that the $f_800$ is not from foreground contaminants. We find that the region with a high star formation rate surface density has a lower $f_1700/f_800$ (higher $f_800/f_1700$) ratio than the diffused regions, suggesting that LyC photons are more likely to escape from the region with the intensive star-forming process. We compare the properties of galaxies with and without LyC detections and find that LyC photons are easier to escape in low mass galaxies.

@misc{bian2017lyman, abstract = {We present the HST WFC3/F275W UV imaging observations of A2218-Flanking, a lensed compact dwarf galaxy at redshift $z\approx2.5$. The stellar mass of A2218-Flanking is $\log(M/M_{\odot}=9.14$ and SFR is 12.5~$M_\odot$~yr$^{-1}$ after correcting the magnification. This galaxy has a young galaxy age of 127~Myr and a compact galaxy size of $r_{1/2}=2.4$~kpc. The HST UV imaging observations cover the rest-frame Lyman continuum (LyC) emission ($\sim800${\AA}) from A2218-Flanking. We firmly detect ($14\sigma$) the LyC emission in A2218-Flanking in the F275W image. Together with the HST F606W images, we find that the absolute escape fraction of LyC is $f_{\rm abs,esc}>28-57\%$ based on the flux density ratio between 1700{\AA} and 800{\AA} ($f_{1700}/f_{800}$). The morphology of the LyC emission in the F275W images is extended and well follows the morphology of the UV continuum morphology in the F606W images, suggesting that the $f_{800}$ is not from foreground contaminants. We find that the region with a high star formation rate surface density has a lower $f_{1700}/f_{800}$ (higher $f_{800}/f_{1700}$) ratio than the diffused regions, suggesting that LyC photons are more likely to escape from the region with the intensive star-forming process. We compare the properties of galaxies with and without LyC detections and find that LyC photons are easier to escape in low mass galaxies.}, added-at = {2017-02-23T10:55:26.000+0100}, author = {Bian, Fuyan and Fan, Xiaohui and McGreer, Ian and Zheng, Cai and Jiang, Linhua}, biburl = {https://www.bibsonomy.org/bibtex/246f49d147da79a617e6d7648af8aeacd/miki}, description = {[1702.06540] High Lyman Continuum Escape Fraction in a Lensed Young Compact Dwarf Galaxy at $z=2.5$}, interhash = {5a6f97c5bfa056766ef4b5320b8372ae}, intrahash = {46f49d147da79a617e6d7648af8aeacd}, keywords = {escape fraction galaxy low mass}, note = {cite arxiv:1702.06540Comment: 5 pages, 2 figures, accepted by ApJL}, timestamp = {2017-02-23T10:55:26.000+0100}, title = {High Lyman Continuum Escape Fraction in a Lensed Young Compact Dwarf Galaxy at $z=2.5$}, url = {http://arxiv.org/abs/1702.06540}, year = 2017 }