ppt

Fermi_HEAPA_2013-03.ppt
Fermi衛星による
最新成果と今後の展望
Mar. 04, 2013@金沢
(高宇連研究会)
T. Mizuno
(広島大学宇宙科学センター)
On behalf of the Fermi-LAT
collaboration
T. Mizuno et al.
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Fermi_HEAPA_2013-03.ppt
Recent Results by
Fermi-LAT and Future
Prospects
Mar. 04, 2013@Kanazawa
(Annual meeting of HEAPA)
T. Mizuno
(Hiroshima Astrophysical
Science Center)
On behalf of the Fermi-LAT
collaboration
T. Mizuno et al.
2 /33
Fermi_HEAPA_2013-03.ppt
Fermi Gamma-ray Space Telescope
• Fermi = LAT + GBM
• LAT = GeV Gamma-ray Space Telescope
(20 MeV ~ >300 GeV; All-Sky Survey )
2008.06 launch
2008.08 Sci. Operation
3c454.3
Cape Canaveral,
Florida
T. Mizuno et al.
1873 sources
Nolan+ 2012, ApJS 199, 31
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Fermi_HEAPA_2013-03.ppt
Fermi-LAT Performance
• New Dataset and Response (Pass7, 2011.08-)
– Improved Aeff in low Energy (E<200 MeV)
– In-orbit calibration of PSF
http://www.slac.stanford.edu/exp/glast/groups/canda/lat_Performance.htm
Effective Area (P7)
Ackermann+12, ApJS 203, 70
(CA: Baldini, Charles, Rando)
T. Mizuno et al.
PSF
good enough for MW analysis
of X-ray sources
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Fermi_HEAPA_2013-03.ppt
Fermi-LAT Performance
• New Dataset and Response (Pass7, 2011.08-)
– Improved Aeff in low Energy (E<200 MeV)
– In-orbit calibration of PSF
http://www.slac.stanford.edu/exp/glast/groups/canda/lat_Performance.htm
Old Aeff (P6)
T. Mizuno et al.
Big improvement over the old
P6 response in E<200 MeV
If you want to analyze data by yourself, please visit
Fermi Science Support Center
http://fermi.gsfc.nasa.gov/ssc/
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Fermi_HEAPA_2013-03.ppt
Fermi-LAT Publications
• Publications by Fermi-LAT members
(Cat I+II+III, as of Dec. 2012)
2008
2009
2010
2011
2012
~300 papers
already published
6-7 papers/month
2FGL catalog paper
is the most cited
paper in 2012
(in astrophysics)
T. Mizuno et al.
http://www-glast.stanford.edu/cgi-bin/pubpub
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Fermi_HEAPA_2013-03.ppt
Introduction: Gamma-Ray Astrophysics
g-rays = CRs x ISM (or ISRF)
Cosmic-rays
Interstellar
Medium
Fermi-LAT (2008-present)
2.4p sr, 20 MeV-300 GeV
• known ISM distribution => CRs
• those “measured” CRs => ISM
A powerful probe to study CRs and ISM in distant locations
T. Mizuno et al.
7 /33
Fermi_HEAPA_2013-03.ppt
Origin and Propagation of Galactic CRs
• uCR~1 eV/cm3 at the solar system
• Vgal=1067-68 cm3, tesc~107 yr
PCR~1041 erg/s
• ESN~1051 erg, FSN~1/30 yr
• If h~0.1
Pinj~1041 erg/s
g-ray
sun
To test this SNR paradigm of CRs,
we need to observe
• CR distribution outside of the solar system
• CRs accelerated at SNRs
T. Mizuno et al.
8 /33
Fermi_HEAPA_2013-03.ppt
Origin and Propagation of Galactic CRs
• uCR~1 eV/cm3 at the solar system
• Vgal=1067-68 cm3, tesc~107 yr
PCR~1041 erg/s
• ESN~1051 erg, FSN~1/30 yr
• If h~0.1
Pinj~1041 erg/s
g-ray
sun
This talk will cover Fermi-LAT obs. of
• diffuse gama-rays
• SNRs
This talk will also cover
• local group galaxies, star-forming galaxies
• extragalactic gamma-ray background
• (+ISM)
T. Mizuno et al.
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Fermi_HEAPA_2013-03.ppt
ISM Component not Visible by Standard Tracers
• ISM has been mapped by radio surveys (HI by 21 cm,
H2 by 2.6 mm CO)
• Fermi revealed a component of ISM not measurable by
those standard tracers
Chamaeleon Molecular Cloud
g-rays w/ CO contour
Residual g-rays when fitted by N(HI)+CO
Ackermann+12, ApJ 755, 22
(CA: Hayashi, TM)
T. Mizuno et al.
10 /33
Fermi_HEAPA_2013-03.ppt
ISM Component not Visible by Standard Tracers
• ISM has been mapped by radio surveys (HI by 21 cm,
H2 by 2.6 mm CO)
• Fermi revealed a component of ISM not measurable by
those standard tracers, confirming an earlier claim based on
EGRET study (Grenier+05)
Residual gas inferred by dust
Residual g-rays when fitted by N(HI)+CO
See also Abdo+10 (ApJ 710, 133), Ackermann+11 (ApJ 726, 81)
and Ackermann+12 (ApJ 756, 4)
T. Mizuno et al.
11 /33
Fermi_HEAPA_2013-03.ppt
CRs outside the Solar System (1)
Mid-high lat. region in 3rd quadrant
• small contamination of IC and
molecular gas
• correlate g-ray intensity with N(HI)
LAT data
model from the LIS
nucleon-nucleon
electronbremsstrahlung
T. Mizuno et al.
• Local CR spectra ~ those
directly measured at the Earth
(uCR~1 eV/cm3)
Abdo+09, ApJ 703, 1249
(CA: TM)
12 /33
Fermi_HEAPA_2013-03.ppt
CRs outside the Solar System (2)
Data
Model
• on average, local CR
spectra ~ those
measured at the Earth
(uCR~1 eV/cm3)
Casandjian+ in prep.
T. Mizuno et al.
13 /33
Fermi_HEAPA_2013-03.ppt
CRs on Galactic Scale
No single model to reproduce the all-sky
data, but overall agreement is good
Outer Galaxy
Diffuse model
(total)
Local
pi0
ebrems.
T. Mizuno 1GeV
et al.
IC
10
Inner Galaxy
100
Ackermann+12, ApJ 750, 3
(CA: Johannesson, Porter, Strong)
14 /33
Fermi_HEAPA_2013-03.ppt
CR Luminosity inferred from a model
• PCR=(6-8)x1040 erg/s and Lg=(7-10)x1038 erg/s
are inferred by (particular) set of models
• MW is electron calorimeter if IC is included
Luminosity of MW
CR p
CR a
Radio
Halo size: 2kpc 4
10
2kpc 4
Models by numerical calculation,
Strong+10 (ApJ 722, L58)
T. Mizuno et al.
g-ray
CR eCR e+
10
Diffusive Reacceleration, zh=4kpc
15 /33
Fermi_HEAPA_2013-03.ppt
SNRs seen by Fermi-LAT
• ten 2FGL sources are now identified as, or associated with SNR
(# of possible association ~60)
• Hadronic scenario is usually favored
T. Mizuno et al.
16 /33
Fermi_HEAPA_2013-03.ppt
SNRs seen by Fermi-LAT
• ten 2FGL sources are now identified as, or associated with SNR
(# of possible association ~60)
• Hadronic scenario is usually favored
T. Mizuno et al.
17 /33
Fermi_HEAPA_2013-03.ppt
IC443 Image and Spectrum
5-10 GeV g-ray image
w/ radio contour
g-ray spectrum w/ pi0-decay
dominated model
2-10
2-10GeV
GeV
PSF
PSF
EGRET
Fermi
MAGIC
VERITAS
Hadronic scenario gives Wp=1x1049 erg
(ECR>500 MeV)
Abdo+10, ApJ 712, 459
(CA: Giordan, Kamae, Rodriguez, Torres)
T. Mizuno et al.
18 /33
Fermi_HEAPA_2013-03.ppt
W44 Image and Spectrum
Deconvolved g-ray image
w/ Spitzer 4.5um contour
(tracer of shocked H2)
g-ray spectrum w/ pi0-decay
dominated model
2-10 GeV
Wp=6x1049 erg, We=1x1048 erg
(ECR>100 MeV)
T. Mizuno et al.
Abdo+10, Science 327, 1103
(CA: Tajima, Tanaka, Uchiyama)
19 /33
Fermi_HEAPA_2013-03.ppt
Pion-Decay Bump in LowE Spectrum
• Spectrum below 200 MeV clearly deviates from
bremsstrahlung and agrees well with a hadronic scenario
IC443
W44
WSN
1x1051 erg
5x1051 erg
WCR
4x1049 (n/20cm-3)-1erg
4x1049 (n/100cm-3)-1erg
Convincing evidence of proton acceleration,
Ackermann+13, Science
ESNh=WCR~1050 erg
T. Mizuno et al.
339, 807
(CA: Funk, Tanaka, Uchiyama)
20 /33
Fermi_HEAPA_2013-03.ppt
Local Group/Starburst Galaxies
• Study CR/ISM interaction in wide range of samples
• Contribution to EGB
LMC
M82
N253
M31
T. Mizuno et al.
SMC
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Fermi_HEAPA_2013-03.ppt
Energy Spectrum
• Starburst -- Hard spectrum by Fermi+IACT (G~2)
• Local Group -- Softer spectrum (G>2.5)
– Escape limited in MW. Short diffusion length in LMC
MW(+) & LMC(+)
M82
G=2.2
Abdo+10, ApJL709, 152
(CA: Bechtol, Dermer, Reimer,
T. Mizuno et al. Rodriguez, Torres)
G=2.7
Abdo+10, A&A 512, A7
22 /33
(CA: Jean, Knodlseder, Porter)
Fermi_HEAPA_2013-03.ppt
SFR-Lg Relation
• A sample of 69 is examined: quasi-linear relation between
star-formation rate and Lg (Lg∝LIR1.0-1.2)
• SFR-Lg relation and hard spectrum implies hadron calorimetry
N1068
N4945
M31
M82
N253
MW
LMC
SMC
Ackermann+12, ApJ 755, 164
T. Mizuno et al. (CA: Bechtol, Cillis, Funk, Torres)
23 /33
Fermi_HEAPA_2013-03.ppt
SFR-Lg Relation
• A sample of 69 is examined: quasi-linear relation between starstar-formation rate and Lg (Lg∝LIR1.0-1.2)
• SFR-Lg relation and hard spectrum implies hadron calorimetry
– NB MW is escape limited
N1068
N4945
M31
M82
N253
MW
LMC
SMC
Ackermann+12, ApJ 755, 164
T. Mizuno et al. (CA: Bechtol, Cillis, Funk, Torres)
24 /33
Fermi_HEAPA_2013-03.ppt
Extragalactic g-ray Background
• GeV gamma-ray sky
= Point sources + Gal. Diffuse gs +
ExtraGal. Diffuse gs
Vela
Geminga
Crab
3c454.3
Fermi-LAT 1 year all-sky map
T. Mizuno et al.
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Fermi_HEAPA_2013-03.ppt
Extragalactic g-ray Background (EGB)
T. Mizuno et al.
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Fermi_HEAPA_2013-03.ppt
Why is EGB Important?
• The EGB may encrypt the signature of the most powerful
processes in astrophysics
Star forming galaxies,
etc.
Blazars contribute
20-100% of the
EGB
Annihilation of
Cosmological
Dark Matter
Particles
accelerated in
Intergalactic shocks
Markevitch+05
T. Mizuno et al.
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Fermi_HEAPA_2013-03.ppt
EGB of EGRET Era
• “Cosmic” Extragalactic Gamma-ray Background (EGB)
– known since 1970s (SAS-2)
E2 x Flux
G ~ 2.1
CXB
(resolved into AGNs)
GeV background
(EGRET)
Sreekumar+98
keV
T. Mizuno et al.
MeV
GeV
28 /33
Fermi_HEAPA_2013-03.ppt
The Fermi EGB
• Fermi data + improved diffuse model
– new EGB spectrum in 0.2-100 GeV
0.1
T. Mizuno et al.
1 GeV
10
+
100
(CA: Ackermann, Porter, Sellerholm)
+”EGB”
point
Instrumental
sources
BG
Abdo+10, PRL 104, 101101
+
gal.
diffuse
G ~ 2.4
=
LAT sky
Featureless PL
softer than EGRET result
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Contribution of Blazars
Fermi_HEAPA_2013-03.ppt
• >70% of resolved high-lat. sources are blazars
• Unresolved Blazars account for 23+/-5(stat)+/12(sys)% of the EGB
logN-logS:
Most of un-associated sources
are likely to be blazars
Fermi EGB vs.
source contribution
0.1
Abdo+10, ApJ 720, 435
T. Mizuno et al.
(CA: Ajello, Tramacere)
1 GeV
10
100
30 /33
Fermi_HEAPA_2013-03.ppt
Contribution of Star-forming Galaxies
• Use Lg-LIR scaling to estimate contribution
• Star-forming galaxies account for 4-23% of the EGB
(~60% at the maximum if we add Blazars and SFGs)
Ackermann+12, ApJ 755, 164
(CA: Bechtol, Cillis, Funk,
Torres)
• Radio galaxies can account for ~25% (e.g., Inoue+11).
Still some room for other source type or truly diffuse
31 /33
T. Mizuno emission.
et al.
Fermi_HEAPA_2013-03.ppt
Future Prospects
• Detailed modeling of Galactic CRs
– CR density gradient, CR density variation (e.g., Ackermann+11, ApJ
726, 81; Ackermann+12, ApJ 755, 22)
• Injection of CRs to the interstellar space
– Detailed observation of SNRs and other accelerators, Cygnus Cocoon
and other star-forming regions (e.g., Ackermann+11, Science 334,
1103)
• New event classification (Pass8)
– Further improvement of acceptance
Cygnus Cocoon
(g-ray excess)
T. Mizuno et al.
Pass 8
(new IRF)
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Fermi_HEAPA_2013-03.ppt
Summary
• Fermi衛星により宇宙線の探査が大きく進んできた(広が
ったガンマ線放射, 宇宙線源候補, 星生成銀河)
–
–
–
–
太陽系は「特別」ではない
SNR起源説で概ね説明可能
星生成銀河はCR p Calorimeter (天の川銀河はescape limited)
系外ガンマ線放射に対する点源の寄与を定量評価
• 宇宙線の注入, 伝播, 分布を調べることが重要
– 宇宙線分布の詳細観測
– SNRほか加速源の詳細観測 (花畑講演も参照)
• 触れられなかった話題：AGN, GRB, PSR/PWN, DM探査
など
Thank you for your Attention
T. Mizuno et al.
33 /33

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