%0 Generic %1 price2016reconstructing %A Price, Layne C. %A Trac, Hy %A Cen, Renyue %D 2016 %K escape fraction reionisation %T Reconstructing the redshift evolution of escaped ionizing flux from early galaxies with Planck and HST observations %U http://arxiv.org/abs/1605.03970 %X While galaxies at $6 z 10$ are believed to dominate the epoch of cosmic reionization, the escape fraction of ionizing flux $f_esc$ and the photon production rate $n_\gamma$ from these galaxies must vary with redshift to simultaneously match CMB and low-redshift observations. We constrain $f_esc(z)$ and $n_\gamma(z)$ with Planck 2015 measurements of the Thomson optical depth $\tau$, recent low multipole E-mode polarization measurements from Planck 2016, SDSS BAO data, and $3 z 10$ galaxy observations. We compare different galaxy luminosity functions that are calibrated to HST observations, using both parametric and non-parametric statistical methods that marginalize over the effective clumping factor $C_HII$, the LyC production efficiency $\xi_ion$, and the time-evolution of the UV limiting magnitude $dM_SF/dz$. Using a power-law model, we find $f_esc łesssim 0.5$ at $z=8$ with slope $2.0$ at $68\%$ confidence with little dependence on the galaxy luminosity function or data, although there is non-negligible probability for no redshift evolution $0$ or small escape fraction $f_esc 10^-2$. A non-parametric form for $f_esc(z)$ evolves significantly with redshift, yielding $f_esc 0.2, 0.3, 0.6$ at $z=6,9,12$, respectively. However, a model-independent reconstruction of $n_\gamma(z)$ predicts a suppressed escaped photon production rate at $z=9$ for the latest Planck data compared to the other models, implying a quicker period of reionization. We find evidence for redshift evolution in the limiting magnitude of the galaxy luminosity function for empirical models of the galaxy luminosity function.

@misc{price2016reconstructing, abstract = {While galaxies at $6 \lesssim z \lesssim 10$ are believed to dominate the epoch of cosmic reionization, the escape fraction of ionizing flux $f_\mathrm{esc}$ and the photon production rate $\dot n_\gamma$ from these galaxies must vary with redshift to simultaneously match CMB and low-redshift observations. We constrain $f_\mathrm{esc}(z)$ and $\dot n_\gamma(z)$ with Planck 2015 measurements of the Thomson optical depth $\tau$, recent low multipole E-mode polarization measurements from Planck 2016, SDSS BAO data, and $3 \lesssim z \lesssim 10$ galaxy observations. We compare different galaxy luminosity functions that are calibrated to HST observations, using both parametric and non-parametric statistical methods that marginalize over the effective clumping factor $C_\mathrm{HII}$, the LyC production efficiency $\xi_\mathrm{ion}$, and the time-evolution of the UV limiting magnitude $dM_\mathrm{SF}/dz$. Using a power-law model, we find $f_\mathrm{esc} \lesssim 0.5$ at $z=8$ with slope $\beta \gtrsim 2.0$ at $68\%$ confidence with little dependence on the galaxy luminosity function or data, although there is non-negligible probability for no redshift evolution $\beta \sim 0$ or small escape fraction $f_\mathrm{esc} \sim 10^{-2}$. A non-parametric form for $f_\mathrm{esc}(z)$ evolves significantly with redshift, yielding $f_\mathrm{esc} \sim 0.2, 0.3, 0.6$ at $z=6,9,12$, respectively. However, a model-independent reconstruction of $\dot n_\gamma(z)$ predicts a suppressed escaped photon production rate at $z=9$ for the latest Planck data compared to the other models, implying a quicker period of reionization. We find evidence for redshift evolution in the limiting magnitude of the galaxy luminosity function for empirical models of the galaxy luminosity function.}, added-at = {2016-05-16T09:55:33.000+0200}, author = {Price, Layne C. and Trac, Hy and Cen, Renyue}, biburl = {https://www.bibsonomy.org/bibtex/2bcc6c31b8e0f7a445d451832bca1ad04/miki}, description = {[1605.03970] Reconstructing the redshift evolution of escaped ionizing flux from early galaxies with Planck and HST observations}, interhash = {6edc853660f5a5535202585e2b10e6f3}, intrahash = {bcc6c31b8e0f7a445d451832bca1ad04}, keywords = {escape fraction reionisation}, note = {cite arxiv:1605.03970Comment: 12 pages, 6 figures, 2 tables}, timestamp = {2016-05-16T09:55:33.000+0200}, title = {Reconstructing the redshift evolution of escaped ionizing flux from early galaxies with Planck and HST observations}, url = {http://arxiv.org/abs/1605.03970}, year = 2016 }