Galactic TeV TeV Gamma Gamma- -Ray Sources Ray Sources Galactic & & Cosmic- -Ray Origin Ray Origin Cosmic Kyoto University Department of Physics Toru Tanimori (CANGAROO Collaboration) Introduction � SNR � Pulsar & Nebulae � Tokyo-Adelaide Joint W ork Shop 2003 、 Jan.
1999 7m φ The first 10m telescope 10m telescope 2000 10m φ 0.4TeV Focal length 8m Parabola 114 (57m 2 ) 80cm CFRP mirrors Number of 552 (1/2 ” ) PMTs FOV ~ 3 ° (4 ° ) Electronics TDC & ADC 0.20 ° (FWHM) Point image 1992 3.8m φ size (< 0.15 ° ) (1.2TeV)
Galactic Targets in CANGAROOII � SNR: e(Synch.+IC) or proton? SN006, RX J1713-3946, RCW86, RX J0852-4622, � Pulsar/nebula: Non-pulsed, Young pulsar + synchrotron nebula IC with 2.7K or SSC by e ± Crab, PSR1706, Vela Pulsar, PSR1509, PSR1259, PSRJ1420(EGRET UN ID) � Others: SS433, Galactic Center � No source due to proton acceleration??
Origin of Cosmic Rays (Galactic) Energetics of Cosmic Rays(<10 16 eV) � Required Energy Supply ~10 40 erg/s ( τ ~ 10 6~7 yrs, ρ CR ~ 1 eV/cm) Unique Candidate SNR E max ＜～ 10 15 eV Extra Galactic Origin (>10 18 eV) � E max ~10 20 eV Spectrum Index -2.5 ~ -3.0 � Shock Acceleration Ion Acceleration Mainly Proton � Widely believed, but little observational � evidences (Whipple No detection from 6SNR)
Process of TeV Gamma-Ray Emission − ∝ E 1 . 6 − ∝ E 2 . 2 − ∝ E 2 . 2 − ∝ E 1 . 6 dE 4 c σ 2 γ = − ∝ E 2 . 2 U photon dt T max 3 I.C. − ∝ E 2 . 2 2 dE B 4 2 σ c γ = dt T max 3 2 Sync
Mechanism of TEV Gamma Emission � π 0 decay induced by Proton Inverse Compton Scattering � of H.E. electrons with h υ scattering +Synchrotron (Radio to X-ray) Index of Gammaray spectrum Flatter spectra than those of similar to that of progenitor progenitor electrons (~ 1.6 ) proton (~ 2.2 for Shock Acceleration) � Bremsstrahlung Low energy cut off (70MeV) In high density region (~ 2.2 for Shock Acceleration) + thermal X-ray emission + emission line (neutral Iron 6.4keV)
Observation by ASCA/SIS Koyama et al.1995 `Power-law Synchrotron Rad. Dominant Power law from NE rim � Pointed out the possibility TeV � Gamma-Ray Emission Several Peaks: Thermal Emission
Significance map 10m result(~ 7 σ） PSF ~ 0.25 deg radius. 3.8m result.(~ 7 σ）
Multi band Spectrum & Fitting Durham S = -2.2 � B ~ 4 μ G � E max ~ 50TeV � E B = max synchro. Spec . 101 μ TeV G Naito et al. Astron. Nach. 320, 1999
SN1006 (electron acceleration) Differential flux(3.8m + 10m) Optical (H α ) Image Winkler et al. astro-ph/0208415
Recent X-ray Observation TeV γ Emission Region XMM-Newton 2-10keV 1keV 0.2keV Chandra SN1006 NE Rim
X-ray & Gamma-Ray Observations of RXJ1713.7-3946 Synch. X-ray Emission(ASCA) TeV-Gamma 3.8m Tele. Tomida, Ph.D., Slane et al, ApJ, 525,1999 1999 Muraishi et al., A&Ap 354, 2000 E γ > ~ 1.5TeV (E –2.5 ) Distance ~ 1kpc or 6kpc ?
Multi wavelength Spectrum of synchrotron-I.C Model (RJX1713) Naito et al 2001(CANGAROO) 2 µ G I .C. Rad. 3 µ G I.C. 3.8m 5 µ G Synchrotron Rad. 10 µ G 20 µ G 1TeV
RX J1713-3946 Spectrum Enomoto et al, Nature, 416, 823 2002 − ∝ E 2 . 8 ∆θ ∆θ =0 o .24(rms) X-ray Infra. Red TeV γ
Proximity of RXJ1713.7-3946 Slane et al, ApJ, 525,1999 Galactic plane CO Image Dist. ~6kpc Density in SNR <<1atom/cm -3 Radio Image @843MHz
Multi wavelength spectrum with Proton Model Nature 416, 823 (2002) Bremsstrahlung 3 µ G I.C. X I.C. 15 µ G Bremsstrahlung X proton from X-ray spectrum Dist. 6kpc -> ~ 10 times of the Crab
0.8 o Counterarguments ∆θ ∆θ =0 o .24 O.Reimer & M.Pohl A&A, 390, L43, 2002 M.Butt et al., Nature 418, 489, 2002
Cas.A X-ray Non-thermal Spectra Bremss. + Synchro . Emission Line X-ray (6.4 keV) From neutral Iron Chandra Image Cas.A 3.4kpc. 5.9’x5.9’
•Supernova remnant: Cas A (HEGRA) Goret et al. 26 th ICRC OG2.2.18, 1999 ● HEGRA 2000
X-ray Synchrotron SNR RCW86 RX J0852-4622 Dist. a few Kpc Dist > 1kpc? Type II ASCA Results Bamba et al. 2000 Slane et al. 2001
RCW86 Chandra Data J .Rho et al., Astro-ph/0208013 Red : 0.5-1 keV, Green :1-2 keV, Blue : 2-8 keV
Keplar non thermal component From whole the SNR
Other characters � Free expansion X-ray remnant ( Hughes 1999 ) � Expanding rate of the remnant ( Hughes 1999 ) X-ray >> radio >> optical X-ray Flux by RXTE (>10 keV ) � × 1/2 � × 10 –2 (Petre et al. 1999) � Hard tail Kepler’s SN1006 (Index ~ 2.5) Brighter than SN1006 ( × 2) � In a dense region? (Bergh et al. 1977, White et al. 1983, and Hughes et al. 1985) Photon Energy (keV)
CANGAROO-III (Stereo Observation) � Array of four 10m telescopes(~2004) � Full Imaging: Angular Res. ~0.1 deg. � Energy Threshold: ~100GeV
PSR1706 Pulsar Nebulae Chandra Images ～ 10arcsec=0.087pc PSR1509 Crab Vela ～ 60arcsec=0.58pc ～ 200arcsec=4.3pc ～ 60arcsec=0.15pc
Pulsar nebulae with highest spin down luminosity (L) Name log L Distance Period log Age (erg s -1 ) (kpc) (ms) (yr) Crab 38.65 2.0 33 3.10 PSR1509-58 37.25 4.4 150 3.19 Vela 36.84 0.5 89 4.05 PSR1706-44 36.53 1.8 102 4.24 ? PSR1706-44 Vela Crab PSR1509-58
Pulsar Nebula Nebula e - Synchrotron X ray B Blackbody NASA/CXC/SAO Inverse Compton Gamma ray 2.7 K CMB Light Cylinder photon
Crab nebula(unpulsed) Aharonian & Atoyan, astro-ph/9803091 SSC Model OK! Max. of acceleration energy ? ~20 TeV or >100 TeV
Crab Nebula
Observation of Crab nebula (Highest Energy) 3.8m Tel. (70TeV) 0. o 1 10mCANGAROO Tel. 10hrs, Observation 5.9 σ 2TeV ~ 20TeV
Multi-wavelength Model (PSR1706) PSR1706-44 unpulsed spectrum, from Nebula <Model> B ~3 µ G 3.8m Different size of Emission regions X -ray : r x < 30 arcsec B=20 µ G Gamma-ray: r γ < 0. ゜ 1 B= 3µ G IC model Sync with 2.7K MBR gamma -ray Aharonian,Atoyan and Kifune et al(1997) X -ray X ray : Spatial resolution Chandra Gamma ray: Energy range CANGAROO - II
Observations with Chandra (PSR1706) Archive Data � The High Resolution Camera (HRC-I) 2000 Feb 11: 46 ksec � Advanced CCD Imaging Spectrometer (ACIS-S) 2000 Aug 13 : 14 ksec ACIS radial profile Nebula 5 arcsec ～ 1 arcsec ( 8.7 × 10 -3 pc ) ～ 10arcsec HRC Image ACIS Image ACIS PSF 80%: ~1arcsec (0.7-9 keV) (0.08-10 keV)
Spectral Analysis(ACIS) N H ～ × 10 21 + 0 . 35 cm -2 5 . 9 － 0 . 25 Pulsar Nebula Index Γ + 0 . 39 + 0 . 34 2 . 0 1 . 4 － － 0 . 72 0 . 30 + 0 . 02 kT(keV) 0 . 14 ---- － 0 . 01 χ 2 /d.o.f 14.8/8 4.9/7 2 × 10 -4 2 × 10 -4 Pulsar Nebula Photon/cm 2 s keV r < 1.2” 1.2”< r < 6” Ｒ ＜ Black body+Power law Power law 2 10 2 Energy(keV) Energy(keV)
TeV Gamma-ray Spectrum Differential Flux Compilation of Integral Flux Statistic error only Alpha distribution Preliminary Durham(98) * Crab Flux E -3.2 (E -1.5 ) Alpha <15 ゜ 5.4 σ 628 ± 116 events
Multi-wavelength Spectrum of PSR 1706 electron Γ～ 2.2 Synch. IC. Model ?? TeV flux ： 10 × X ray flux Synchrotron cut off > 10keV OR B~ 20 µ G & E e ~400 TeV B~ 1mG & E e ~20TeV difficult to explain Sync-IC(2.7k CMB) model
Nebula Where is TeV Gamma ray from? X ray(Chandra) Synchrotron -IC model Size : small Magnetic field : weak Max electron energy: > 100TeV >100 TeV electrons escape quickly ～ 0.087pc without synchrotron energy loss Contradict CANGAROO ( ～ 1TeV) Optical(VLT) Near Pulsar V< 24.5 TeV gamma rays are absorbed by IR photons TeV γ + IR photon → e + e － Optical magnitude < 24.5 V=17.3 The effect of absorption is low Lundqvist et al(1999)
A Model of TeV Gamma-rayRadiation Curvature Radiation Spectrum Model of PSR 1706-44 10 -10 erg cm -2 s -1 × EGRET α inc =60 ° e ± → GeV gamma ray + IR photon J. Takata & S. Shibata(Yamagata Univ) (Curvature ) Infrared data → NO e ± + IR photon → TeV gamma ray (IC) Optical data → upper limit Estimated IR spectrum from X ray and radio data
Summary � VHE Gamma-Ray Sources: Pulsar Nebulae, AGN, SNR � Almost Sources due to electrons: I.C. Gamma Rays Where is Proton?? Where is Cosmic Origin?? ( SN1006 ) But, � One Convincing Candidate of Proton Acceleration Site; RXJ1713-3934 � Another Synch.X-ray SNRs ; RCW86 and RX J0852-4622 � TeV Gamma-rays from pulsars: Crab & PSR1706 synch. nebulae observed from almost gamma-ray pulsars, but acceleration in Nebula OK?
Recommend
More recommend
