High-z Massive Star Cluster
Search by [OIII] observation
with ALMA
Hiroshi Matsuo (NAOJ)
Akio Inoue (Osaka Sangyo Univ.)
with helps of Kasai and Kubo (Toho Univ.)
High-z universe beyond
redshift 8

To probe the period of Re-Ionization.
 Interstellar space should be already
contaminated by heavy elements from Pop III.
 High UV field prevent formation of dust,
hence low extinction.
 Massive stars are formed in clusters, nearby
counter parts are R136 in 30Dor, LMC.
 SFG and GRB can trace massive star clusters.
FIR SED of
Starburst galaxies

OI, OIII
 NII, NIII
 CII
Fischer et al. (1999)
FIR atomic fine structure lines

OI
– 63.185mm
– 145.54mm




OIII 35.1eV
– 51.815mm
– 88.356mm
NII 14.5eV
– 121.80mm
– 205.30mm
NIII 29.6eV
– 57.330mm
CII 11.3eV
– 157.68mm
4.745THz
2.060THz
5.0×105 cm-3
1.5×105 cm-3
5.786THz
3.393THz
3.4×103 cm-3
5.0×102 cm-3
2.461THz
1.460THz
2.8×102 cm-3
4.5×101 cm-3
5.229THz
3×103 cm-3
1.901THz
2.7×103 cm-3
Carina Nebula by ISO LWS
[CII]
Mizutani, Onaka, Shibai. (2002)
AKARI [O III] 88mm in Carina Nebula
[OIII] 88 mm (3.4 GHz)
I = 1.4e-5 W/m2/sr
R = 1 arcmin
W= 2.7e-7 sr
3.7 pW/m2
TB = 110 K
(Dv=3km/s)
30Dor region and
R136
300 Mo stars
[OIII] 88mm is
observed widely
distributed around
R136
Contour: MIPS 24mm
Kawada et al. (2011)
Observation with ALMA

Primordial Massive Star-Forming Region
 [OIII] 52um, 88um (ion potential 35 eV)
– Probe of electron density and UV radiation

Z > 8 observation of SFGs and GRBs
 Site of Cosmic Re-ionization
Example of [OIII] observations
in submillimeter-wave
~ 10 -18 W/m2
Ferkinhoff (2010)
High-z Star-Forming Galaxies
M82
Line Intensity W/m2
10-17
[NeII]
[SiIII]
z=0.1
[OI] [OIII] [CII]
[OIII]
ALMA Bands
10 9
8
7
6
Herschel
z=0.2
10-18
z=0.5
10-19
SPICA
z=1
10-20
z=2
z=3
10-21
z=5
z=8
z=10
10 um
100 um
Wavelength
1 mm
[OIII] 88 mm line intensities

Single massive cluster
– 1 ×10-5 W/m2/sr
from Carina
– 10 arcmin in diameter @ 50 kpc from 30 Dor
7 × 10-11 W/m2 at z=10-5
2 × 10-22 W/m2 at z=8
1.7 mJy for 10 km/s @ 350 GHz
angular diameter 10 milli-arcsec
[OIII]88 flux estimation
Assumption 1:
Assumption 2:
𝐿[OIII]88
𝐿Hβ
𝐿Hβ
𝜈UV 𝐿ν UV
1. Cloudy calculations
(Z=1/5Zsun, log10U=-1.0, log10nH=0.0)
2. Kawada et al. (2011) 30 Dor in LMC obs.
≈2
=
𝐹Hβ
𝜈obs 𝐹ν obs
≈ 0.01
𝜈obs = 𝜈UV /(1 + 𝑧)
SFR conversion laws (~100Myr constant SF):
𝐿Hβ = 1.6 × 1041 erg s−1
𝑆𝐹𝑅
𝑀sun yr −1
𝑆𝐹𝑅
𝜈UV 𝐿𝜈
= 1.4 × 1043 erg s−1
UV
𝑀sun yr −1
For Z=1/5Zsun (Inoue 2011)
For Z=Zsun (Kennicutt 1998)
Therefore, we obtain
𝐹[OIII]88
≈ 0.02
𝜈obs 𝐹ν obs
𝜈obs = 𝜈UV /(1 + 𝑧)
NOTE: we may need to correct F_obs(UV) for dust extinction.
A. Inoue (2011)
Expected Brightness

Gravitational lensed sources
– 25-26 mag at H160
– 10 mJy Dv=100km/s
– Limited redshift information

HUDF sources (Dec. -28deg)
– 27-28 mag at H160
– 2 mJy Dv=100km/s
– Many candidates at z~8
Redshift probability
distributions
Z=8.11 for [OIII] 88um
Z=8.74
High-z universe beyond
redshift 8

To probe the period of Re-Ionization.
 Interstellar space should be already
contaminated by heavy elements from Pop III.
 High UV field prevent formation of dust,
hence low extinction.
 Massive stars are formed in clusters, nearby
counter parts are R136 in 30Dor, LMC.
 SFG and GRB can trace massive star clusters.
宇宙背景放射観測の現状



宇宙赤外線背景放射（CIB） ＝ 観測値 ー 前景放射
前景放射： 太陽系（黄道光）、銀河系（星、星間ダスト放射）
近赤外域には銀河の重ねあわせでは説明できない超過成分
黄道光（前景放射）
背景放射
CMB
系外銀河 第一世代の星
の重ねあわせ
Ly-?
From
S. Matsuura
（SUBARU, HST, Spitzer, BLAST）
19
Carinae Nebula at 2.3 kpc

International Workshop on Japanese Art and Culture: The 6th EU