Key Extragalactic Sciences with SPICA: a brief

Key Extragalactic
Sciences with SPICA:
a brief overview of MRD
October 19, 2009
Hideo Matsuhara(ISAS/JAXA) & SPICA SWG
SPICA Mission Requirement
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]
[2]
[3]
銀河の誕生と
進化過程の解明
Resolution of
Birth and
Evolution of
Galaxies
銀河星間空間における
物質輪廻の解明
The Transmigration of
Dust
in the Universe
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
Resolution of Birth and Evolution of Galaxies
Birth of 1st Stars
Cosmic Re-ionization
SPICA
Formation/Evolution of
Cluster of Galaxies
Formation/Evolution of Stars & Super-Massive
Blackholes in Galaxies
Credit: NASA
contributors

Objective 1:


Objective 2:


Tohru Nagao (Ehime U.), Toru Yamada (Tohoku U.)
Objective 4:


Mai Shirahata, Shuji Matsuura, Hideo Matsuhara (ISAS), Mitsunobu
Kawada (Nagoya U.)
Objective 3:


Eiichi Egami (U. Arizona), Kimiaki Kawara (U. Tokyo), Takashi
Ichikawa (Tohoku U.), Motoki Saito (Ehime U.)
Masa Imanishi (NAOJ), Shinki Oyabu (ISAS), Masayuki Akiyama
(Tohoku U.)
Objective 5:

Yusei Koyama, Taddy Kodama (NAOJ), Toshinobu Takagi (ISAS)
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 starforming 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
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 10. Is dust obscuration
playing any role?
Strong PAH emitter search upto z~10
PAH luminous galaxies @z=0.6
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 z~10 @ R~20 is enough with SAFARI
• Low-R spectroscopy enables to overcome the confusion limit
• How large / deep should we survey with SAFARI??
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!
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 farinfrared 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 farinfrared 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
Resolving capability of the
Cosmic Infrared Background (CIB)
With an ideal pointsource sensitivity limited
by source confusion as a
function of telescope
diameter
(Dole et al. 2004)
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, miniquasars(AGN), etc.), it may form the
far-infrared background.
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
(0.03-0.3MJy/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.
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
One example of SPICA’s
outstanding capability :
BLISS
MIR-FIR
metalicity diagnostics!
Why metallicity at 0 < z < 3 ?
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
Possible caveat: selection bias
~ using “rest-frame optical” diagnostics
 observing only “un-obscured” galaxies
~ how about “obscured” galaxies??
Maiolino, Nagao, et al. (2008)
Application to ISO data (only few low-z galaxies)
metallicity diagnostics
physical properties
M82, CenA, NGC1068, Antennae show consistent line ratios.
AGN effects are negligible? (should be checked…)
Data: Colbert+99, Unger+00, Fischer+96, Spinoglio+05
Feasibility
SAFARI GOAL
BLISS
• [NIII] 57mm
– M82 (dwarf SB) :
detectable out to z~1 with
BLISS
– ULIRGs are detectable out
to z~2 with SAFARI
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 supermassive 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
Optically (X-ray)
selected AGN
Buried AGN
5-35 mm spectra of ULIRGs
Active Sturburst
Buried AGN
Starburst + AGN
PAH
PAH
18um
9.7um
18um
9.7um
9.7um
PAH
PAH
18um
9.7um
9.7um
18um
9.7um
With PAH
Spitzer
& AKARI, only 24
micron-very-bright
ULIRGs (biased sample)
PAH
weak Silicate abs. strong
strong
could be studied at z > 1: SPICA enables us to go to z > 3 and to
general ULIRGs at z > 1 !!
Evolution of galaxies and the growth of
super-massive blackholes
z=0.7-1.0
z=1.0-1.5
4000A break strength
z=0.2-0.7
Obs. limit
log( Stellar mass (M_sun))
Contours : the galaxy distribution in SXDF
Blue filled (spec-z) and open (phot-z) circles : X-ray sources (AGN)
At z=1.0-1.5, AGN are associated with massive star-forming galaxies, while at z=0.2-0.7, 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 )
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
“Wide-field” is powerful !
z = 30
z=5
z=3
JWST/MIRI
MIRACLE
z=2
z=1
MIRACLE
z=0
MIRACLE
MIRACLE
M=6×10^14 Msun, 20Mpc×20Mpc (co-moving)
Yahagi et al. (2005)
MIR galaxies in the transition region
MIR fraction
MIR galaxies prefer cluster outskirts, but avoid cluster centre
: 15um
source
AKARI
log (density)
Koyama
et al. (2008)
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
RDCS0910 @z=1.1  16um
RDCS1252 @z=1.24  17um
(Tanaka et al. 2007, 2008 )
Summary
Understand the role of environment along the cosmic time
through wide-field cluster study with SPICA
SF activity
(SFR, SSFR, etc)
Field
Group
Cluster
?
?
z
?
WHAT’S SPICA MISSION?
IN SYNERGY WITH HERSHEL,
JWST, TMT, ALMA?
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
ALMA will be available soon
commission from 2012
• Overwhelming spatial resolution in the submm
• Star-forming galaxies with SFR~100 Mo/yr @ 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
Then, JWST will come!!
To be launched in 2014
• Extreme sensitivity @0.6-5mm
– Re-ionization sources @ z>7 may be identified and
studied
• Suprime spatial resolution (68mas@2mm)
– Origin of galaxies’ morphology may be answered
etc. etc.
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)

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

Uniqueness of SPICA

Overwhelming Imaging Sensitivity at 20-100 mm
(MIRACLE, SAFARI)



Overwhelming mapping speed !!
MIRACLE should have large FoV as much as
possible
Capability of spectro-imaging at 35-210mm
(SAFARI)
 Overwhelming Spectroscopic sensitivity at
20 – 400 mm (MIRMES, SAFARI, BLISS)
 High-dispersion spectroscopy at 4-8, 12-18mm
Sensitivity for spectral lines
(1 hour, 5)
IRSx0.1
BLISS
1.5-2 orders better than Herschel
Better than JWST @20mm
35
36
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?
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
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

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