تقرير
SILVERRUSH. IV. Ly$\alpha$ Luminosity Functions at $z = 5.7$ and $6.6$ Studied with $\sim$ 1,300 LAEs on the $14-21$ deg$^2$ Sky
| العنوان: | SILVERRUSH. IV. Ly$\alpha$ Luminosity Functions at $z = 5.7$ and $6.6$ Studied with $\sim$ 1,300 LAEs on the $14-21$ deg$^2$ Sky |
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| المؤلفون: | Konno, Akira, Ouchi, Masami, Shibuya, Takatoshi, Ono, Yoshiaki, Shimasaku, Kazuhiro, Taniguchi, Yoshiaki, Nagao, Tohru, Kobayashi, Masakazu A. R., Kajisawa, Masaru, Kashikawa, Nobunari, Inoue, Akio K., Oguri, Masamune, Furusawa, Hisanori, Goto, Tomotsugu, Harikane, Yuichi, Higuchi, Ryo, Komiyama, Yutaka, Kusakabe, Haruka, Miyazaki, Satoshi, Nakajima, Kimihiko, Wang, Shiang-Yu |
| سنة النشر: | 2017 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We present the Ly$\alpha$ luminosity functions (LFs) at $z=$5.7 and 6.6 derived from a new large sample of 1,266 Ly$\alpha$ emitters (LAEs) identified in total areas of 14 and 21 deg$^2$, respectively, based on the early narrowband data of the Subaru/Hyper Suprime-Cam (HSC) survey. Together with careful Monte-Carlo simulations that account for the incompleteness of the LAE selection and the flux estimate systematics in the narrowband imaging, we have determined the Ly$\alpha$ LFs with the unprecedentedly small statistical and systematic uncertainties in a wide Ly$\alpha$ luminosity range of $10^{42.8-43.8}$ erg s$^{-1}$. We obtain the best-fit Schechter parameters of $L^{*}_{{\rm Lya}}=1.6^{+2.2}_{-0.6} (1.7^{+0.3}_{-0.7}) \times10^{43}$ erg s$^{-1}$, $\phi^{*}_{{\rm Lya}}=0.85^{+1.87}_{-0.77}\ (0.47^{+1.44}_{-0.44})\times10^{-4}$ Mpc$^{-3}$, and $\alpha=-2.6^{+0.6}_{-0.4}\ (-2.5^{+0.5}_{-0.5})$ at $z=5.7$ ($6.6$). We confirm that our best-estimate Ly$\alpha$ LFs are consistent with the majority of the previous studies, but find that our Ly$\alpha$ LFs do not agree with the high number densities of LAEs recently claimed by Matthee/Santos et al.'s studies that may overcorrect the incompleteness and the flux systematics. Our Ly$\alpha$ LFs at $z=5.7$ and $6.6$ show an indication that the faint-end slope is very steep ($\alpha \simeq -2.5$), although it is also possible that the bright-end LF results are enhanced by systematic effects such as the contribution from AGNs, blended merging galaxies, and/or large ionized bubbles around bright LAEs. Comparing our Ly$\alpha$ LF measurements with four independent reionization models, we estimate the neutral hydrogen fraction of the IGM to be $x_{\rm HI}=0.3\pm0.2$ at $z=$6.6 that is consistent with the small Thomson scattering optical depth obtained by Planck 2016. Comment: 21 pages, 14 figures, accepted for publication in PASJ special issue |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/pasj/psx131 |
| URL الوصول: | http://arxiv.org/abs/1705.01222 |
| رقم الأكسشن: | edsarx.1705.01222 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/pasj/psx131 |
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