Science with SPICA

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Science withSPICA
Presented by H. Matsuhara, M. Imanishi, T.
Onaka, K. Enya on behalf of SPICA Science
Working Group 2006.11.2
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Activities in JapanSPICA Science Working Group
(SSWG)

• 1. Cosmic History
• 1.1. Galaxy Formation and Evolution
• Nishi, Susa, Kodama, Yamada, Matsuhara, Yoshida,
  Omukai, etc.
• 1.2. Active Galactic Nuclei
• Imanishi, Nakagawa, etc.
• 2. Star Formation and Evolution
• Tamura, Hayashi, Pyo, Okamoto, Sugitani, Nagata,
  Inutsuka, Imanishi, Kamaya, Aikawa
• 3. Very Low-Mass Stars star Death
• 3.1. Very Low-Mass Stars
• Nakajima, Tamura
• 3.2. Star Death
• Izumiura, Yamamura, Onaka, Miyata, Kawabata
• 4. Planet Formation and Evolution
• Tamura, Ida, Fukagawa, Hirao, Honda, Kokubo
• 5. Solar System
• Watanabe, Hasegawa, Kawakita, Furusyo, Sato,
  Sekiguchi, Kasuga, Otsubo

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First Stars and Re-ionization

• SPICA can detect z10 star forming galaxies
  (SFGs) via detecting Ha lines.
• SPICA can also detect STFGs via detecting H2 line
  emissions if the first stars at z3 exist.
• 10-30mm region
• Z20 STFGs too difficult

Star formations at zero metal.
SFR 100 MSUN yr-1 No extinction
Nishi
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Forming Galaxies

• From the Era of discovery
• To the era of Unveiling their nature !!
• Also
• even z3-5 is very important !!
• (10-30 of stars in z3-4 LBGs LAEs are
  primordial stars
• Jimenez Heiman (2006) Nature)

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Lyman a Emitter z6.96(World record so far)
Iye et al. (2006) Nature

• By using NB973 of Subaru/S-cam
• LAE search _at_ z6.94-7.11? 2 candidates

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LAE cluster _at_z6 (SXDS)

• 515 LAEs
• 2 proto-clusters

Ouchi et al. (2005) ApJL
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Lyman a Blobextended Lya Emitter
25 190 kpc
Z3.1
z3.1 LBG
Broad-band NB composite
Subaru/S-cam image (Matsuda et al. 2004) of SSA22
Blob1 (Steidel et al. 2000)
LyaEmitter only
Yamada
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Lyman a Blobs diversity in their nature

• Energy source (Nilsson et al. 2006)
• 1) hidden AGNs
• 2) Star-formation super-winds
• 3) Cold accretion of primordial gas onto the
  dark-matter halo?
• Key observations are
• Mid Far-IR Spectroscopy of Ha, H2, and many
  metal lines
• Mid-IR morphology unveiling the morphology
  of stellar population (if exist)
• SPICA 3.5m can have such capabilities!