%0 Generic %1 shapley2016q1549c25 %A Shapley, Alice E. %A Steidel, Charles C. %A Strom, Allison L. %A Bogosavljević, Milan %A Reddy, Naveen A. %A Siana, Brian %A Mostardi, Robin E. %A Rudie, Gwen C. %D 2016 %K detection direct escape fraction %T Q1549-C25: A Clean Source of Lyman-Continuum Emission at $z=3.15$ %U http://arxiv.org/abs/1606.00443 %X We present observations of Q1549-C25, an ~L* star-forming galaxy at z=3.15 for which Lyman-continuum (LyC) radiation is significantly detected in deep Keck/LRIS spectroscopy. We find no evidence for contamination from a lower-redshift interloper close to the line of sight in the high signal-to-noise spectrum of Q1549-C25. Furthermore, the morphology of Q1549-C25 in V_606, J_125, and H_160 Hubble Space Telescope (HST) imaging reveals that the object consists of a single, isolated component within 1". In combination, these data indicate Q1549-C25 as a clean spectroscopic detection of LyC radiation, only the second such object discovered to date at z~3. We model the spectral energy distribution (SED) of Q1549-C25, finding evidence for negligible dust extinction, an age (assuming continuous star formation) of ~1 Gyr, and a stellar mass of M_*=7.9x10^9 M_sun. Although it is not possible to derive strong constraints on the absolute escape fraction of LyC emission, f_esc(LyC), from a single object, we use simulations of intergalactic and circumgalactic absorption to infer f_esc(LyC)>=0.42 at 95% confidence. The combination of deep Keck/LRIS spectroscopy and HST imaging is required to assemble a larger sample of objects like Q1549-C25, and obtain robust constraints on the average f_esc(LyC) at z~3 and beyond.

@misc{shapley2016q1549c25, abstract = {We present observations of Q1549-C25, an ~L* star-forming galaxy at z=3.15 for which Lyman-continuum (LyC) radiation is significantly detected in deep Keck/LRIS spectroscopy. We find no evidence for contamination from a lower-redshift interloper close to the line of sight in the high signal-to-noise spectrum of Q1549-C25. Furthermore, the morphology of Q1549-C25 in V_606, J_125, and H_160 Hubble Space Telescope (HST) imaging reveals that the object consists of a single, isolated component within 1". In combination, these data indicate Q1549-C25 as a clean spectroscopic detection of LyC radiation, only the second such object discovered to date at z~3. We model the spectral energy distribution (SED) of Q1549-C25, finding evidence for negligible dust extinction, an age (assuming continuous star formation) of ~1 Gyr, and a stellar mass of M_*=7.9x10^9 M_sun. Although it is not possible to derive strong constraints on the absolute escape fraction of LyC emission, f_esc(LyC), from a single object, we use simulations of intergalactic and circumgalactic absorption to infer f_esc(LyC)>=0.42 at 95% confidence. The combination of deep Keck/LRIS spectroscopy and HST imaging is required to assemble a larger sample of objects like Q1549-C25, and obtain robust constraints on the average f_esc(LyC) at z~3 and beyond.}, added-at = {2016-06-03T10:24:44.000+0200}, author = {Shapley, Alice E. and Steidel, Charles C. and Strom, Allison L. and Bogosavljević, Milan and Reddy, Naveen A. and Siana, Brian and Mostardi, Robin E. and Rudie, Gwen C.}, biburl = {https://www.bibsonomy.org/bibtex/2093b6ca2bf9356b6da42ca9e87bb2c3c/miki}, description = {[1606.00443] Q1549-C25: A Clean Source of Lyman-Continuum Emission at $z=3.15$}, interhash = {6943c45bb45803530194fcb51d90a3de}, intrahash = {093b6ca2bf9356b6da42ca9e87bb2c3c}, keywords = {detection direct escape fraction}, note = {cite arxiv:1606.00443Comment: 6 pages, 5 figures, submitted to ApJ Letters}, timestamp = {2016-06-03T10:24:44.000+0200}, title = {Q1549-C25: A Clean Source of Lyman-Continuum Emission at $z=3.15$}, url = {http://arxiv.org/abs/1606.00443}, year = 2016 }