1. Key Extragalactic Sciences with SPICA: a brief overview of MRD
October 19, 2009
Hideo Matsuhara(ISAS/JAXA) & SPICA SWG

2. SPICA Mission Requirement

3. Approaches to perform SPICA Scientific Objectives
〈銀河誕生のドラマ〉
をさぐる
〈惑星系のレシピ〉
をさぐる
[ 1 ]
銀河の誕生と
進化過程の解明
Resolution of Birth and Evolution of Galaxies
[ 2 ]
銀河星間空間における 物質輪廻の解明
The Transmigration of Dust in the Universe
[ 3 ]
惑星系形成過程の
総合理解
Thorough Understanding of Planetary System Formation
遠方宇宙／初期宇宙
Distant/Early Universe
近傍宇宙（恒星系）
Local Universe/Stellar system

4. Resolution of Birth and Evolution of Galaxies
Birth of 1st Stars　
Cosmic Re-ionization
SPICA
（図の説明）約１３０億年と言われる宇宙の歴史の中で、最初に生まれた星－現在の銀河を形作る星とは全く異なる星が存在した可能性が、宇宙背景放射やガンマ線バーストなどの観測的研究から示唆されている。この第一世代の星の最有力な証拠である水素分子スペクトル線は、SPICAでしか観測できない赤外線波長に存在する。SPICAは他に並ぶものの全くない超高感度なスペクトル線による撮像観測を行い、宇宙のいつ、どこにこのような第一世代の星たちが存在したのか、という謎の解明に挑む。
Formation/Evolution of Cluster of Galaxies
Formation/Evolution of Stars & Super-Massive Blackholes in Galaxies
Credit: NASA 4

5. contributors Objective 1: Objective 2: Objective 3: Objective 4:
Eiichi Egami (U. Arizona), Kimiaki Kawara (U. Tokyo), Takashi Ichikawa (Tohoku U.), Motoki Saito (Ehime U.)
Objective 2:
Mai Shirahata, Shuji Matsuura, Hideo Matsuhara (ISAS), Mitsunobu Kawada (Nagoya U.)
Objective 3:
Tohru Nagao (Ehime U.), Toru Yamada (Tohoku U.)
Objective 4:
Masa Imanishi (NAOJ), Shinki Oyabu (ISAS), Masayuki Akiyama (Tohoku U.)
Objective 5:
Yusei Koyama, Taddy Kodama (NAOJ), Toshinobu Takagi (ISAS)

6. Extragalactic Science ：Objective #1
Nature of re-ionization sources
Objective
We will discover active star-forming galaxies at re-ionization epoch, and reveal their nature with SPICA’s unique capability.
Target
We will search for redshifted ionized H lines, H2 lines and dust emission band (z>4) from active star-forming galaxies at z>4 with mid-& far-IR spectroscopy. We also search for star-forming galaxies at z>4 by using flux magnification due to cluster gravitational lens, and dust-cocooned Gamma Ray Bursts at z>4.
SAFARI　　BLISS MIRACLE

7. Tracing the Cosmic Star Formation History at 4<z<10
Bouwens et al. (2008)
Rest-frame UV-selected galaxies show a steep decline of star
formation rate density from z~4 to Is dust obscuration
playing any role?

8. Strong PAH emitter search upto z~10
PAH luminous
z~2 SMG
(Pope+ 2008)
7.7um PAH luminosity of z~2 SMGs: ~5e1010 L for the most luminous ones (Pope et al. 2008)  Requires a flux sensitivity of ~10-19 Wm-2 to detect up to R~20 is enough with SAFARI
Low-R spectroscopy enables to overcome the confusion limit
How large / deep should we survey with SAFARI??

9. Probing Early Universe with hyper-luminous H2 Emission Lines
Egami et al.
(2006)
Do they already exist beyond z=4?
Pure rotational lines S(1), S(2) from Zw3146　（LIRG with ~1010MSUN warm H2 gas) class galaxy at z=6-7 can be detected with BLISS.
SPICA/BLISS is unique observatory to do H2 line science of early Universe!

10. Extragalactic Science ：Objective #2
Origin of Cosmic IR Background
Objective
We will resolve the cosmic far-infrared background light into individual objects, and reveal the origin of the cosmic far-infrared background residual brightness and fluctuations.
Target
We will resolve the cosmic far-infrared background light into individual far-infrared objects with 3 times or more higher spatial resolution than that of AKARI. We then evaluate far-infrared background residual brightness and its fluctuations after removal of the individual objects, and reveal its origin through detailed analysis such as multi-wavelength correlation.
SAFARI　　BLISS MIRACLE

11. Resolving capability of the Cosmic Infrared Background (CIB)
With an ideal point-source sensitivity limited by source confusion as a function of telescope diameter (Dole et al. 2004)

12. Motivation: The near-infrared background
IRTS & COBE found excess emissions which cannot be nearby galaxies
Proto-galaxies (e.g. pop-III stars, mini-quasars) at z~10?
Measuring the anisotropy is powerful to identify them.
If substantial fraction of the energy of the NIR background is converted to dust emissions (IGM dusts, mini-quasars(AGN), etc.), it may form the far-infrared background.

13. The far-infrared background measurement with SPICA
AKARI found :
1) Excess brightness around 100um
Corresponding to
>10^10 gals/sr for S<100 uJy
Proto-galaxies?
2) Large-scale fluctuations at 10’-30’
~5% of the mean CIRB level
Very red foreground galaxies?
Objective: detection of spectral features (hot dust, silicate absorption, etc.) and fluctuations of the far-infrared background of dust emissions from proto-galaxies at z>10.
To resolve the excess background and the large-scale clustering, the detection limit of ~100uJy (5) and ~1mJy (5) is required, respectively.
To measure the FIR background at similar levels to the NIR background ~1-10 nW/m2/sr ( MJy/sr at 100um), the detection limit of ~150uJy (5) is required.
Angular power spectrum of the fluctuations to ~1 degree (FOV >2x2 sq.deg) is required to discriminate proto-galaxies with distinctive spectrum.

14. MIRMES MIRACLE SAFARI BLISS
SPICA Mission Requirement Document
Extragalactic Science: Objective #3
Diagnostics of distant IR galaxies
Objective
We will reveal physical & chemical condition of high-z galaxies with precise correction for dust attenuation, based on understanding of interstellar environment and dust emission.
Target
We will reveal interstellar environment and dust emission characteristics of high-redshift galaxies out to z~3 through PAH emission as well as atomic and molecular emission lines with broad-band mid- & far-IR moderate resolution spectroscopy. These observations allow us to reveal the physical & chemical conditions of dusty galaxies in the early universe (up to 9 Gyr ago) with precise correction for dust attenuation.
MIRMES　MIRACLE SAFARI　　BLISS
One example of SPICA’s outstanding capability :
MIR-FIR metalicity diagnostics!

15. Why metallicity at 0 < z < 3 ?
Maiolino, Nagao, et al. (2008)
Tight relation between galaxy
mass and metallicity (M-Z rel.)
~ constraints on galaxy
evolutionary models
Mass-dependent evolution
in the M-Z relation
~ chemical version of the
“down-sizing” evolution
Mass – metallicity relation obtained by rest-frame optical spectroscopy. Interestingly dwarfs rapidly evolving in metalicity, while the massive galaxies are evolving slower - so called down- sizing also seen in metallicity
Possible caveat: selection bias
~ using “rest-frame optical” diagnostics
 observing only “un-obscured” galaxies
~ how about “obscured” galaxies??

16. Application to ISO data (only few low-z galaxies)
metallicity diagnostics
physical properties
These are example of low-redshift measurement vertical in [OIII]/ [NII] measred for M82 etc. [N II]/[N III]
Since [OIII] line ration is not sensitive to ionizing parameter U
M82, CenA, NGC1068, Antennae show consistent line ratios.
AGN effects are negligible? (should be checked…)
Data: Colbert+99, Unger+00, Fischer+96, Spinoglio+05

17. SAFARI GOAL
BLISS
Feasibility
[NIII] 57mm
M82 (dwarf SB) : detectable out to z~1 with BLISS
ULIRGs are detectable out to z~2 with SAFARI

18. Extragalactic Science ：Objective #4
Super-Massive Black-Hole growth history
Objective
In order to understand the role of supper-massive black holes (SMBHs) in the galaxy evolution, we will make a survey for the forming SMBHs, that may not be observed easily in other methods due to the obscuration by dust, from the present to the early universe.
Target
We will make infrared imaging & spectroscopic observations of approx. 1,000 candidates in search for the forming super-massive black holes (SMBHs), that can not be observed easily in other methods due to the obscuration of dust, from the present to the early universe. Supplementing these results with the results of observations for the galaxy formation history, we will understand the role of SMBHs in the galaxy evolution.
MIRACLE MIRMES SAFARI 　　　

19. 5-35 mm spectra of ULIRGs Active Sturburst Buried AGN Starburst + AGN
Optically (X-ray)
selected AGN
Buried AGN
5-35 mm spectra of ULIRGs
Active Sturburst
Buried AGN
Starburst + AGN
9.7um
18um
PAH
With Spitzer & AKARI, only 24 micron-very-bright ULIRGs (biased sample)
could be studied at z > 1: SPICA enables us to go to z > 3 and to
general ULIRGs at z > 1 !!
PAH strong
PAH weak　Silicate abs. strong

20. Evolution of galaxies and the growth of super-massive blackholesz= z= z=
4000A break strength
log( Stellar mass (M_sun))
Obs. limit
Contours : the galaxy distribution in SXDF
Blue filled (spec-z) and open (phot-z) circles : X-ray sources (AGN)
At z= , AGN are associated with massive star-forming galaxies, while at z= , the AGN number associated with massive red galaxies increases.
Do some X-ray AGN follow the track from star-forming to red, passive galaxies (and their activities are going to turn off)? How about dusty obscured AGN?.
SPICA/SAFARI broad-band imaging survey over ~100 sq. deg!!
Subaru XMM deep survey field (SXDS) (Akiyama et al.天文月報２００８年１月号 )

21. Extragalactic Science ：Objective #5
Cosmic SF & Mass Assembly History
Objective
We will reveal the star-formation & mass assembly history of galaxies in relation to the forming processes of the galaxy clusters and the large scale structures, as well as the environmental effect on the galaxy evolution.
Target
In the early universe where the star forming activities was at a peak, we will undertake imaging wide-area survey and observe the galaxy clusters and the large scale structures at infrared wavelength, to which the redshifted emitting energy shifts. The large survey area (corresponding to ~300 Mpc) can trace the large scale structures, and we will reveal the star formation history in the early universe (up to 9 Gyr ago) as well as the mass assembly history and its environmental effect on the galaxy evolution.
MIRACLE　　SAFARI　

22. “Wide-field” is powerful !
z = 30
z = 5
z = 3
JWST/MIRI
MIRACLE
MIRACLE
z = 2
z = 1
z = 0
MIRACLE
MIRACLE
Yahagi et al. (2005)
M=6×10^14 Msun, 20Mpc×20Mpc (co-moving)

23. MIR galaxies in the transition region
MIR galaxies prefer cluster outskirts, but avoid cluster centre
log (density)
MIR fraction
: 15um source
AKARI
Koyama et al. (2008)

24. Clusters at “cluster desert” (1<z<2)
The number of 1<z<2 known clusters is now increasing
SPICA + FMOS collaboration will be powerful
FMOS
MIRI
MIRI
 16um
 17um
(Tanaka et al. 2007, 2008 )

25. ? ? ? Summary z SF activity (SFR, SSFR, etc) Field Group Cluster
Understand the role of environment along the cosmic time through wide-field cluster study with SPICA ? ?
SF activity
(SFR, SSFR, etc) z
Field
Group ?
Cluster

26. What’s SPICA Mission? In Synergy with HERSHEL, JWST, TMT, ALMA?

27. Herschel launched !!! 14 May 2009 Deep FIR imaging :
3.5m aperture : confusion limit substantially improved but very limited cosmic volume
FIR & Submm spectroscopy – still limited to z<<1
Credit: ESA

29. ALMA will be available soon commission from 2012
Overwhelming spatial resolution in the submm
Star-forming galaxies with SFR~100 z>3 will be studied, though survey area may be limited to a few 100 arcmin2 (since FOV~20”)
coordination with LMT CCAT may give information on for unbiased sample of z>3 submm galaxies

30. Then, JWST will come!! To be launched in 2014
Extreme
Re-ionization z>7 may be identified and studied
Suprime spatial resolution
Origin of galaxies’ morphology may be answered
etc. etc.

31. TMT (Thirty Meter Telescope) aimed commission in 2018
Caltech/UC + Japan + Canada
Understanding the nature of 1st stars
Superior Spectroscopic sensitivity than JWST
Suprime spatial resolution with AO (30mas)

32. Remember Basic Concept of SPICA
3-m monolithic primary mirror, diffraction limited at 5mm
COOLED (<6K) telescope as well as focal plane instruments
Space Observatory mission, for mid- & far-IR astronomy

33. Uniqueness of SPICA
Overwhelming Imaging Sensitivity at mm (MIRACLE, SAFARI)
Overwhelming mapping speed !!
MIRACLE should have large FoV as much as possible
Capability of spectro-imaging at mm (SAFARI)
Overwhelming Spectroscopic sensitivity at 20 – 400 mm (MIRMES, SAFARI, BLISS)
High-dispersion spectroscopy at 4-8, 12-18mm

34. Sensitivity for spectral lines (1 hour, 5s)
IRSx0.1
BLISS

35. 1.5-2 orders better than Herschel
Better than

37. SPICA’s probe for re-ionization Era (z~10)
Probes free from the confusion limit
PAH Emitter
Cosmic Far-IR Background Fluctuations
Gravitational lens
H2 emitter
Dust-obscured hyper-luminous AGN
Dust-cocooned GRB afterglow
Evidence of Formation of dust / metals in the re-ionization era
ULIRGs at z~10 : if exit, how they are related to the 1st stars?

38. SPICA shall unveil invisible universe obscured by dust
Some Key Words expressing SPICA Mission Objective..
SPICA shall unveil invisible universe obscured by dust
1st MetaLs in Early Universe Cosmic SFH/BHGH Origin of our solar system

39. 중요한 것은 눈으로 보이지 않는다
大切なものは目で見えないんだよ。
l'essentiel est invisible pour les yeux
What is essential is invisible to the eye, but visible to SPICA’s HEART