LAES POWERED BY AGN AND THEIR IMPACTS ON COSMIC REIONIZATION - PowerPoint PPT Presentation

LAES POWERED BY AGN AND THEIR IMPACTS ON COSMIC REIONIZATION SUNGHYE BAEK (SNS, ITALY) COLLABORATION WITH ANDREA FERRARA SKA IN EAST ASIA 2013 NAGOYA UNIVERSITY 5-7 JUNE 2013 2013 MNRAS 432L 6B

THE 21 CM SIGNAL AND THE 21 CM SIGNAL AND REIONIZATION REIONIZATION MOST PROMISING PROBE OF THE DARK AGES AND • REIONIZATION SIGNAL REDSHIFTED TO METER WAVE (50-200 MHZ), • DETECTABLE WITH SKA THE INTENSITY OF THE 21CM DEPENDS ON THE • TEMPERATURE OF THE IGM : WE CAN CONSTRAIN SOURCE PROPERTIES (X-RAYS) USING THE 21 CM POWER SPECTRUM X-RAYS HEATING → INCREASE GAS TEMPERATURE (IGM) → REDUCE THE INTENSITY OF THE 21 CM SIGNAL

X-RAYS AND THE IGM X-RAYS AND THE IGM TEMPERATURE TEMPERATURE BAEK+2010

POWER SPECTRUM OF POWER SPECTRUM OF Δ T T B B BAEK+2010

X-RAY SOURCE CANDIDATE AT X-RAY SOURCE CANDIDATE AT HIGH-Z HIGH-Z QSO : THE MOST RECENT RECORD AT Z=7.1 HOSTING 10 9 • M SOL BH THEIR PROGENITORS Z > 7 : AGN HOSTING MINI OR • INTERMEDIATE BH WHERE X-RAY INTENSITY UNDER DETECTION LIMIT THE ROLE OF MINI(INTERMEDIATE) BH IN ACTIVE NUCLEUS • GALAXY : ALTERNATIVE SOURCE FOR LYMAN ALPHA? WHAT IS THE PROPERTIES OF SUCH LAE POWERED BY AGN • WITH RESPECT TO THE ONE POWERED BY STARBURST?

LYMAN APHA EMITTERS LYMAN APHA EMITTERS A PROMINENT LY α (N=2 → N=1 : • 1216 Å) LINE EMITTING GALAXIES (EW ≥ 20 Å) HIGH REDSHIFT, STARBURST • GALAXIES, HIGH HI DENSITY (Z ≅ 2-7) STAR FORMATION → IONIZING • UV → RECOMBINATION → EMITTING LY α SOURCES OF REIONIZATION •

ORIGINS OF LYMAN PHOTON ORIGINS OF LYMAN PHOTON RECOMBINATION • IN THE IONIZED GAS • STAR FORMING HIGH DENSE REGION • STRONG UV FIELD, SHORT RECOMBINATION TIME • VERY EFFICIENT PROCESS • EXCITATION - DEEXCITATION • IN THE NEUTRAL GAS • STELLAR WIND VIA COOLING (LYMAN ALPHA BLOB) • X-RAYS •

MOTIVATION MOTIVATION Galaxies at high redshift (z>6) are compact and contains plenty of neutral gas. When AGN in LAE is faint (X-rays flux under detection limit) and obscured (no broaden emission), How can we distinguish and identify them from LAE powered by starburst?

LAE WITH AGN LAE WITH AGN X-rays detection on LAE • Gawiser et al. 2006 at z~3 • Zheng et al. 2010 at z~4.5 • Broaden emission line • Ouchi et al. 2008 at z~3-4, 800 candidates • 1 % contains AGN • Brightest LAEs with Log(L α ) > 43.4-43.6 erg s -1 • Variable photometry • Shibuya et al. 2012 at z~7.3 • Temporal luminosity enhancement • Shibuya et al. 2012 associated with a QSO, an AGN, or SN

NUMERICAL SIMULATION NUMERICAL SIMULATION Hydrodynamics Gadget2 • Consider both ISM 2 X 512 3 DM and baryon • and IGM to DM : 6.68 X 10 5 M sol • modeling LAE at Baryon : 1.32 X 10 5 M sol • z=6.6 UV, X-ray RT with LICORICE • A Point source at the center • Ly α RT with LICORICE • 10 cMpc/h Source from every cell where • Log(L α ) > 37 [erg s -1 ]

3 MODELS - DIFFERENT SED 3 MODELS - DIFFERENT SED 1. Starburst model STARBURST99 : 0.02 Z sol , Salpeter IMF, 1-100 M sol cut off Continuous SFR : 10 M sol /yr 2. The Compton thick AGN (Shang et al. 2011) UV and X-rays confined in a cone with opening θ =45° 3. The Compton thin AGN Isotropically emitted for X-rays 100eV < h ν < 500eV AGN composite spectra Normalized to have the same X-rays photoionization rate ˙ Q = 3 × 10 54 s − 1 A halo with M h =1.17X10 11 M sol

TOTAL INTRINSIC LYA TOTAL INTRINSIC LYA X-rays Recombination Lya production : X-rays ➘ ➘ with time • Recombination ➚ ➚ with time • Early : X-ray dominated ★ Later : Recombination ★ dominated

Neutral fraction Ly α radiative transfer Ly α production UV, X-rays RT 1 st post processing Ly α Surface Brightness Ly α RT 60 pkpc/h 2 nd post processing

Nature of LAE powered by AGN

1. Evolution of skewness S w Early phase Later phase

Lower skewness z~5.7 Ouchi et al. 2008

2. Evolution of the SB profile (the SB map) Early phase or X-ray effect dominates Later phase or recombination dominates

Skewness vs. FWHM of SB Starburst can not make Parametrized curves with time t = 0.02, 0.04, 0.06, 0.08, 1.00 • Myr from left to right The shaded area denotes AGN-powered LAE identification • criterion S w < 0 and FWHM ≥ 1.5”

Summary Alternative X-ray/Lya source for high-z (z>6) • High redshift (z>6) LAE probably contains obscured and • less powerful AGN For given Q, X-rays can boost Ly α luminosity with several • orders when there is plenty of neutral gas (e.g. when AGN just turns on or large amount of accreting gas) Nature of LAE powered by AGN • The lower skewness S w < 0 • Extended SB profile, having FWHM greater than FWHM • of PSF(seeing size) FWHM ≥ 1.5”