AGILE observation of Galactic sources Andrea Giuliani Istituto Astrofisica Spaziale e Fisica Cosmica, Milano ( INAF ) on behalf of the AGILE Team
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
The AGILE Mission only ~100 kg of Payload only ~100 W of PL absorbed power only 350 kg of satellite
The AGILE Mission AGILE combines a gamma-ray imager (30 MeV- 30 GeV) with a hard X-ray imager (18-60 kev) both with large FOVs (1-3 sr) and optimal angular resolution
AGILE performances Field of view: ~ 3 sr 2 times better than EGRET
AGILE: 1.5 years in orbit April 23rd, 2007 : Launch from Sriharikota (India) Dec. 1st, 2007 : Starts the Cycle-1 Guest Observer Program Dec. 1st, 2008 : Starts the Cycle-2 Guest Observer Program Feb 2009 : ~ 9300 orbits
The AGILE gamma-ray sky (E > 100 MeV)
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
Why to study the γ ray interstellar emission? As noise : source identification and analysis.
Why to study the γ ray interstellar emission? As signal : probe of CR, IS Matter, ISRF
Why to study the γ ray interstellar emission? As signal : probe of CR, IS Matter, ISRF Origin of GeV excess (if confirmed!) Electronic harder spectrum? Protonic harder spectrum? Galactic vs local electronic spectrum Inhomogeneous gamma emissivity? X ratio value and variation in Galaxy IC contribution to diffuse emission Galactic vs Extragalactic diffuse emission CR sources SNR Stellar associations?
Gamma-Ray Emission of the Interstellar Medium Cosmic rays (p and e-) Interstellar Matter Neutral Hydrogen (60 %, 21 cm line) Molecular Clouds (40 %, CO emission, X ratio) InterStellar Radiation Field (stars, dust, CBM)
Gamma ray emission of the ISM Cosmic e- Cosmic p HI regions σbr Fe nhi σpp Fp nhi Mol. Clouds σbr Fe nco Xratio σpp Fp nco Xratio ISRF σic Fe Uph Proton-proton collisions Bremsstrahlung Inverse Compton
Gamma Ray Spectrum S E = 1 4π [ q pp r, E n r qbr r, E n r q IC r, E U r ] drd Gamma Ray Intensity [ ph cm-2 s-1 sr-1 MeV-1 ] Electron Bremsstrahlung πo decay Inverse Compton 100 1000 Gamma-Ray energy [MeV]
Radio Data deprojection Galactic rotation curve Clemens 1985 Radio Data Gas density
The neutral Hydrogen (HI) Two phase medium in pressure balance 2. Cold (100 K) Mass Dense sheet No grav. Bound n = 20 60 cm-3 3. Warm (6000 K) 30 60 % volume
The neutral Hydrogen (HI) Ground level of neutral hydrogen (12S1/2) is split into two sublevels F = J + I = 0,1 Tiny energy separation (t = 1.1 107 years) Radio emission at 1420.4 MHz or 21 cm Spin temperature TS
Neutral Hydrogen Survey Leidn-ArgentineBonn (LAB) survey of galactic HI at 21 cm (Kalberla et al 2005) Spatial resolution: 30 Velocity resolution: 1.03 km/s Velocity range: -450,400 km/s Sensitivity: 0.07 K
The molecular clouds Concentrated in Giant Clouds (104 108 Msol) self graviting with n > 103 cm-3 Optically thick (dust, H2) Along spirala arms Small scale thickness (120 pc)
The molecular clouds H2 is homopolar No vibrational or rotational emission CO is the abundant molecule after H2 CO emits strong line radiation at 2.6 mm (J 1 0) CO tracer of H2 nh2 proportional to LCO
CO Survey (Dame et al. 2001) CO observation (J 1 0 115 GHz) 31 survey combined Spatial resolution: 12 or more Velocity resolution: 0.65 km/s Sensitivity: 0.62 K X = nhi/nco = 1.8 1020 cm-2 K-1 km-1 s
Hydrogen distribution H mean density (averaged on b < 5 )
Interstellar Radiation Field Model of the ISFR: Far Infrared Near Infrared Optical/UV + CBR
Cosmic-Rays Trying with different cosmic ray models Physical models GALPROP Sources, diffusion and energy loss simulated GALPROP (Strong & Moskalenko) Fichtel 91
HI The γ-ray emission model (I quadrant) ISRF H2
The γ-ray emission model (I quadrant)
The γ-ray emission model (-90 < l < 90)
AGILE Observations (-90 < l < 90)
AGILE Observations vs Model (-90 < l < 90)
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
The first AGILE Bright Sources Catalog http://www.asdc.asi.it/agilebrightcat/
The first AGILE Bright Sources Catalog 8 Blazars 9 Pulsars IC 443 LSI +61 303 ~ 20 UnID
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
November 2008: 11 detections >3 sigma. New GammaRay Pulsars Pellizzoni et al., 2009, in press
A new variable millisecond gamma-ray pulsar in a globular cluster EROT= 2.2x1036 erg/s P = 3 ms d = 4.9 kpc
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
SNR IC 443
IC 443 SNR and Molecular Clouds From Dickman et al. 1992
IC 443 SNR and Molecular Clouds
TeV source (MAGIC,VERITAS) EGRET source (Hartman et al. 1999)
IC 443 Gev Source TeV Source see also : Torres et al. MNRAS, 387, 2008 Aharonian & Atoyan, A&A, 309, 1996
IC 443 Fit: αp = αe = 2.25 20 Msol see also Gaisser et al., 1998
Summary of the Presentation The AGILE Mission The diffuse emission model Galactic Sources Pulsars IC 443 Unidentified Sources
Not only pulsars?
Center 0 330 Norma 31 Scutum 315 Crux 51 Sagittarius 285 Carina 80 Cygnus 260 Vela Anticenter
The Cygnus Region 3EG J2022+4317 (WR 140) Gamma Cygni? Cyg OB 2? TeV 2032+4130? Cyg X-3? PSR J2021+3651! (Halpern et al., ApJ, 2008) 3EG J2022+4317
The Carina Region Westerlund 2? Eta Carinae? PSR J1016-5857!
Identification of counterparts Source confusion Resolution ~ N. Counts More observations for better positioning --> Cycle 2
Conclusions and Future prospects Very exciting time for gamma-ray astrophysics AGILE performances are improving ~ t Cygnus and Carina regions deep covered during Cycle 2
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