1. Akio K. INOUE (Osaka Sangyo University) Kousai, K. (Tohoku U), Iwata, I. (NAOJ), Matsuda, Y. (Caltech), Nakamura, E. (Tohoku U), Horie, M. (Tohoku U), Hayashino, T. (Tohoku U), Tapken, C. (MPIA), Akiyama, M. (Tohoku U), Noll, S. (U Innsbruck), Yamada, T. (Tohoku U), Burgarella, D. (OAMP), Nakamura, Y. (Tohoku U) First Stars IV at Kyoto 20121

2. Contents Finding Lyman continuum emitting LAEs with Subaru Extreme strength of Lyman continuum of the LAEs A new SED model with the Lyman limit ‘bump’ An interpretation of the LAEs’ nature: Galaxies with massive Pop III or EMP stellar population? First Stars IV at Kyoto 20122

3. Subaru Lyman continuum search z=3—4 is the unique (translucent) window to observe Lyman continuum from ground-based large telescopes. Subaru/Suprime-Cam + custom-made narrowband filter which captures Lyman continuum (~900 A) of galaxies in a proto-cluster at z=3.1 (SSA22 field). Iwata, Inoue, et al. 2009, ApJ, 692, 1287 Hubble Ultra Deep Field (NASA) time Neutral universe Big Bang (ionized) Recombination Ionized universe Reionization redshift ~6~1000 Earth’s atmosphereIGM attenuation (Inter-Galactic Medium) z=3-4 First Stars IV at Kyoto 20123

4. Subaru Lyman continuum search Iwata, Inoue, et al. 2009, ApJ, 692, 1287 We pre-selected LAEs at z=3.1 by NB497 and confirmed their Ly-alpha by spectroscopy (i.e. all our sample LAEs have spec-z), then we observe their Lyman continuum by NB359. First Stars IV at Kyoto 20124 NB359 NB497 V R i’

5. Lyman continuum emitting LAEs ~10% LAEs are detected in NB359 (rest~900A) NB359 (900A) NB359 (900A) R (1500A) R (1500A) ACS 814 (2000A) ACS 814 (2000A) Iwata, Inoue, et al. 2009, ApJ, 692, 1287 First Stars IV at Kyoto 20125

6. Some show offset of Ly-A and Ly-C ＶＬＴ／ ＶＩＭＯＳ ＡＧＮ ３ arcsec Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 20126

7. Strong Lyman continuum Observed LAEs ● ： LAE with LyC (No LyA offset) ○ ： LAE with LyC （ LyA offset ） ■ ： LBG with LyC Pop. Synth. model (fesc=1) Constant SFR ▽： Normal Pop I/II （Ｓａｌｐｅｔｅｒ ＩＭＦ， Ｚ＝１ / ５０，１ / ５ Ｚｏ） Instantaneous １Ｍ ｙｒ △： Normal Pop I/II × ： Top-heavy Ｉ ＭＦ ＊： Massive ＥＭ Ｐ ◇： Massive Pop III Stronger Ly-C Inoue et al. 2011, MNRAS, 411, 2336 Very young (~1 Myr) Normal Pop I/II + median IGM + dust NB359 is affected by IGM First Stars IV at Kyoto 20127 fesc=1

8. Strong Lyman continuum Observed LAEs ● ： LAE with LyC (No LyA offset) ○ ： LAE with LyC （ LyA offset ） ■ ： LBG with LyC Pop. Synth. model (fesc=1) Constant SFR ▽： Normal Pop I/II （Ｓａｌｐｅｔｅｒ ＩＭＦ， Ｚ＝１ / ５０，１ / ５ Ｚｏ） Instantaneous １Ｍ ｙｒ △： Normal Pop I/II × ： Top-heavy Ｉ ＭＦ ＊： Massive ＥＭ Ｐ ◇： Massive Pop III Stronger Ly-C Inoue et al. 2011, MNRAS, 411, 2336 Massive Pop III + median IGM + dust NB359 is affected by IGM First Stars IV at Kyoto 20128 fesc=1

9. Escape of Nebular Continuum Nebular Lyman continuum may escape if stellar Lyman continuum escapes from galaxies! Recombination process produces Lyman continuum. Photon-bounded nebula neutral ionized No escape both of stellar and nebular Lyman continua Matter-bounded nebula neutral ionized Both of stellar and nebular Lyman continua can escape Inoue 2010, MNRAS, 401, 1325 First Stars IV at Kyoto 20129 fesc=0 0<fesc<1

10. escaping stellar + nebular intrinsic stellar intrinsic nebular Lyman limit ‘bump’ <= Energy re-distribution by nebulae (assumed to be independent of  NB359 V R i’ Inoue 2010, MNRAS, 401, 1325 First Stars IV at Kyoto 201210

11. Normal (Salpeter IMF), young (1 Myr) Pop II (Z=0.0004) Inoue et al. 2011, MNRAS, 411, 2336 The sequence is a function of fesc. First Stars IV at Kyoto 201211 Cumulative probability of the IGM attenuation

12. Massive (~100 Msun), young (1 Myr) Pop II (Z=0.0004) Inoue et al. 2011, MNRAS, 411, 2336 The sequence is a function of fesc. First Stars IV at Kyoto 201212 Cumulative probability of the IGM attenuation

13. Massive (~100 Msun), young (1 Myr) EMP Inoue et al. 2011, MNRAS, 411, 2336 The sequence is a function of fesc. First Stars IV at Kyoto 201213 Cumulative probability of the IGM attenuation

14. Massive (~100 Msun), young (1 Myr) Pop III Inoue et al. 2011, MNRAS, 411, 2336 The sequence is a function of fesc. First Stars IV at Kyoto 201214 Cumulative probability of the IGM attenuation

15. LAEs emitting Lyman continuum 3 LAEs without Ly-A offset They are probably ‘real’ Lyman continuum emitters. Even if we adopt the Lyman ‘bump’ model, these objects still favor massive (~100 Msun) and young (~1 Myr) Pop III, EMP, or Pop II galaxies with fesc~0.5. For the Pop II case, very massive IMF is required at Z~1/50 Zsun which is much higher than that expected for the IMF transition. 5 LAEs with Ly-A offset Possibly the NB359 source is different from Ly-A emitting source: we may have a few foreground contaminations. However, it is statistically difficult that all the 5 are foreground: P<1% These objects require massive (~100 Msun) and young (~1 Myr) Pop III galaxies along a transparent line-of-sight even with the Lyman ‘bump’ model of fesc~0.5. Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 201215

16. Pop III + normal: Two components? Normal Pop II with dust + Pop III (Lyman ‘bump’) Blue: no dust for Pop II Cyan: E(B-V) = 0.1 Green: E(B-V) = 0.2 Red: E(B-V) = 0.3 Pop III of 0.1-10% in the stellar mass is enough. LAEs seem to have more Pop III than LBGs. Late Pop III at z=3! Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 201216

17. Conclusion Lyman continuum emitting LAEs at z=3 possibly have a significant amount of the ‘primordial’ stellar population. Stellar mass fraction is ~1% (0.1-10%). In future, we hope to obtain a more robust signature by spectroscopy. [OIII]/H-beta ratio can be an indicator (Inoue 2011). Near-infrared spectroscopy with TMT? We will enlarge the sample with Subaru/Hyper-Suprime- Cam (HSC) which has 10 times larger FOV than the current S-Cam. First Stars IV at Kyoto 201217

18. First Stars IV at Kyoto 201218

19. NIR spectroscopy to constrain Z [OIII]/H  < 0.1  Z < 1/1000 Zsun Inoue 2011, MNRAS, 415, 2920

20. Close-up of a “bluest” LAE NB359(880A) R (1600A) u (930A) i (1900A) z (2200A) NB497-BV (Ly  ) Only one strong emission line at 4986 A suggests that this is an object at z=3.1! FWHM of the line in medium-resolution spectrum is 300 km/s. Spatially extended line image (1.”3 against 1.”0 PSF) First Stars IV at Kyoto 201220

21. SED of a “bluest” LAE Lyman limit “bump”!? ＮＢ４９７ ＮＢ３５９ ｕＢＶ Ｒ ｉ’ｉ’ ｚ’ｚ’ c First Stars IV at Kyoto 201221

22. A possible scenario Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 201222

23. A possible scenario Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 201223

24. A possible scenario Inoue et al. 2011, MNRAS, 411, 2336 First Stars IV at Kyoto 201224