GeV-TeV Gamma-ray Astronomy - PowerPoint PPT Presentation

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GeV-TeV Gamma-ray Astronomy

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International Workshop on Extremely High Energy Cosmic Rays, March 22-23, 2001, Kashiwa GeV-TeV Gamma-ray Astronomy Masaki Mori ICRR, Univ. Tokyo – PowerPoint PPT presentation

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Title: GeV-TeV Gamma-ray Astronomy


1
GeV-TeV Gamma-ray Astronomy
International Workshop on Extremely High Energy
Cosmic Rays, March 22-23, 2001, Kashiwa
  • Masaki Mori
  • ICRR, Univ. Tokyo

http//icrhp9.icrr.u-tokyo.ac.jp
2
Gamma-ray astronomy short history
  • Prediction of nuclear gamma-rays Hayakawa 1952
    Morrison 1958
  • Ground-based Cherenkov Jelly (1953), Chudakov
    (1960-)
  • Prediction of emission from the Crab nebula
    Cocconi 1959 nuclear Gould 1965 inverse
    Compton
  • Satellites OSO-3 (1967-68), SAS-2 (1972-73),
    COS-B (1975-82)
  • Compton Gamma Ray Observatory EGRET/COMPTEL/OSSE/B
    ATSE (1991-2000)
  • Imaging Cherenkov Whipple, CANGAROO, HEGRA
    (1980s-1990s)

3
Gamma-ray emission mechanisms
  • Gamma-rays are produced in inherently non-thermal
    processes!

p matter
e? B
e? matter
e? h?
4
CGRO/EGRET
  • Apr 1991 Jun 2000
  • 30 MeV 30 GeV
  • ?675.85?(100 MeV/E)0.534

5
EGRET Allsky Map
6
EGRET observed intensity
Galactic longitude
Galactic latitude
7
EGRET diffuse emission model
8
EGRET sources observed - model
9
Diffuse gamma-ray spectrum
  • Flatter than expected (E -2.75) why?? Flatter
    proton/electron spectrum??

Nishimura et al.
EGRET
JACEE
?0
Whipple
Brems
uniform
IC


S. Hunter, Heidelberg WS, 2000
10
Third EGRET catalog
R.C. Hartman et al., ApJS, 1999
11
EGRET point source summary
R.C. Hartman et al., ApJS, 1999
12
Pulsars
Radio Princeton catalog (706 pulsars), 1995
MeV only
(GeV candidates 1046-58, 065614, J02184232)
GeV Thompson, Heidelberg WS, 2000
13
Pulsars radio vs gamma-ray
Thompson, Heidelberg WS, 2000
14
Gamma-ray pulsar light curves
GLAST proposal
15
BL Lacs and EGRET AGNs
RED EGRET 3rd catalog AGNs Green Padovani
Giommi MN 1995
TeV Whipple, HEGRA, CAT, 7TA, Durham
16
Gamma-ray blazars
H(igh freq. peaked) BL ? X(-ray selected)
BL L(ow-freq. peaked) BL ? R(adio-selected) BL
  • Mostly FSRQ and BL Lacs

Lin et al. ApJ 1999
Mukherjee et al. ApJ 1997
17
Multiwavelength spectrum of AGNs
  • Double-peaked structure synchrotron inverse
    Compton

Kataoka, Ph.D 2000
Mrk 421 (z0.03, XBL)
PKS0528134 (z2.1, FSRQ)
? ?IC ?2?sync
? ?sync
Kubo et al. ApJ 1998
18
EGRET unidentified sources
  • Low vs High latitude
  • Persistent vs Variable
  • Geminga-like pulsars?
  • SNRs?
  • OB associations?
  • Gould belt?

I. Grenier, GeV-TeV WS, 1999
19
EGRET unIDs and SNRs
RED EGRET 3rd catalog unID Green D.A. Greens
catalog
TeV CANGAROO
TeV HEGRA
GeV Esposito et al. ApJ 461, 1996
20
Extragalactic diffuse gamma-rays
  • Single power-law E 2.10?0.03 (30 MeV-100 GeV)
  • Unresolved point sources (ex. Blazars
    etc.)?Upscattered CMB?

E 2.10?0.03
P. Sreekumnar et al., ApJ 1998
21
Imaging Cherenkov technique
22
Image parameters
?
(Simulation)
D.J. Fegan, J.Phys.G, 1997
23
Example of image cut analysis
  • Hadron rejection power 100

Whipple
CANGAROO (Vela)
M. Punch et al., Nature, 1992
T. Yoshikoshi et al., ApJ, 1997
24
TeV catalog 2000
Classification Object Group Remark
Grade A (gt5s,multiple) Crab PSR1706-44 Mrk 421 Mrk 501 Many CANGAROO, Durham Many Many Plerion Plerion AGN (BL Lac) AGN (BL Lac)
Grade B (gt5s) SN1006 Vela RXJ1713.7-3946 PKS2155-304 1ES1959650 BL Lac CANGAROO CANGAROO CANGAROO Durham Utah7TA Crimea SNR Plerion SNR AGN (BL Lac) AGN (BL Lac) AGN (BL Lac)
Grade C (strong but with somequalifications) Cas A Cen X-3 1ES2344514 3C66A Geminga B1509-58 HEGRA CT Durham Whipple Crimea Crimea CANGAROO SNR X-ray binary AGN (BL Lac) AGN (z0.44) Pulsar Plerion
T.C. Weekes, Heidelberg WS, 2000
25
TeV sky 2000
26
TeV observations of Plerions
S. Fegan, astro-ph/0102324
27
Crab nebula
  • Unpulsed spectrum

Aharonian Atoyan, astro-ph/9803091 / Heidelberg
WS, 2000
synchrotron
IC
28
Crab pulsar spectrum where is the cutoff?
Musquere, 26th ICRC, 1999
29
TeV observations of shell-type SNRs
S. Fegan, astro-ph/0102324
30
Supernova remnant SN1006
T. Naito
31
SNR SN1006 - interpretation
Naito et al. Astron. Nach. 320, 1999
  • SynchIC
  • Only IC?
  • No pro-tons?

32
TeV observations of AGNs
(Detection of 1ES1426428 (z0.13) is claimed by
Whipple but not published)
Krennrich, astro-ph/0101120
33
AGN Mrk 421 variability
  • Time scale lt a few hours
  • Correlation with X-ray flux

Takahashi et al. ApJ 542, 2000
Gaidos et al., Nature, 383, 1996
34
AGN Mrk 421 spectrum
z0.031
  • Synchrotron inverse Comptonmodel workswell?
    e? origin
  • Proton modelstill possible

Takahashi et al. ApJ 542, 2000
synchrotron
inverse Compton
One-zone SSC model d14, B0.14G
35
AGN TeV gamma-ray absorption by IR background
Mean free path for ee- pair production
IR Background
Protheroe et al. astro-ph/0005349
36
AGN Mrk 501 spectrum
z0.033
Crisis??
Protheroe et al. astro-ph/0005349
Aharonian et al. AAp 349, 1999
37
Next generation projects
  • SatellitesMeV INTEGRAL 15keV-10MeV, 2002-
    ACT (Advanced Compton Telescope) 300keV-20MeV,
    2008?GeV AGILE 30MeV-50GeV, 2003- GLAST
    20MeV-300GeV, 2005?
  • Ground-basedCANGAROO-III 4?10m, Australia,
    2000-2004-MAGIC 1?17m, Canary Island, 2001-HESS
    4?12m, Namibia, 2002-VERITAS 7?10m, Arizona,
    2004-

38
Sensitivity of future detectors
39
Summary
Gamma-ray observation maps the non-thermal
Universe!
  • Plerions (pulsar nebula)Inverse Compton? ?
    synchrotron origin?
  • PulsarsCutoff in pulse component? ? polar
    cap/outer gap
  • SNRsp0 contribution? ? cosmic ray origin
  • AGNsGamma-ray source e or p?Intergalactic IR
    ? cosmology
  • EGRET unIDs, Neutralinos, GRBs,
    QG,Galactic/extragalactic diffuse,, and more?
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