Galactic sources of VHE gamma rays

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MPI Kernphysik, Heidelberg Humboldt Univ.
Berlin Ruhr-Univ. Bochum Univ. Hamburg LSW
Heidelberg Univ. Tübingen Ecole Polytechnique,
Palaiseau APC Paris Univ. Paris VI-VII Paris
Observatory, Meudon LAPP Annecy LAOG
Grenoble LPTA Montpellier CEA Saclay CESR
Toulouse Durham Univ. Dublin Inst. for Adv.
Studies Charles Univ., Prague Yerewan Physics
Inst. North-West Univ., Potchefstroom Univ. of
Namibia, Windhoek
VHE Gamma Ray Astronomy with the High Energy
Stereoscopic System Highlights W. Hofmann MPIK
Heidelberg
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MPI Kernphysik, Heidelberg Humboldt Univ.
Berlin Ruhr-Univ. Bochum Univ. Hamburg LSW
Heidelberg Univ. Tübingen Ecole Polytechnique,
Palaiseau APC Paris Univ. Paris VI-VII Paris
Observatory, Meudon LAPP Annecy LAOG
Grenoble LPTA Montpellier CEA Saclay CESR
Toulouse Durham Univ. Dublin Inst. for Adv.
Studies Charles Univ., Prague Yerewan Physics
Inst. North-West Univ., Potchefstroom Univ. of
Namibia, Windhoek
VHE Gamma Ray Astromony with the High Energy
Stereoscopic System Highlights W. Hofmann MPIK
Heidelberg
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Four telescopes, 107 m2 mirror area each 960
PMT cameras, field of view 5o Observation in
moonless nights, 1000 h / year Each night
several objects are tracked and 300 images
recorded per second
First analysis (almost) online in the same night
on PC cluster in Namibia Final analysis and
calibration in Europe Energy threshold 100
GeV Sensitivity 1 Crab in 25 h
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• H.E.S.S. Highlights
• Galactic sources
• Galactic plane survey
• Supernova remnants
• Pulsar wind nebulae
• Binaries
• The Galactic Center
• Extragalactic sources
• Details physics discussion in parallel sections

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H.E.S.S. HighlightGalactic Plane Survey
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H.E.S.S. HighlightGalactic Plane Survey
? S. Funk, OG 23 ? A. Lemiere, OG 23
15 new TeV sources 3 known
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Ensemble characteristics
Most sources are extended (size resolved if gt
23)
Spectra measured for all sources relatively hard
, ltGgt 2.3
Photon index
Source size
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What are they ?
(smoothed image)
5 sources could be associated with SNR, e.g.
HESS J1834-087 3 could be pulsar wind nebulae,
typically displaced from the pulsar some
coincide with EGRET, ASCA, unidentified
sources 3 have no counterpart known to us
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HESS J1813-178 now identified
(smoothed image)
HESS J1813-178
White et al. 2005 Brogan et al. 2005 20 cm
VLA Ubertini et al., 2005 Integral
Beam
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HESS J1614-518, J1708-410 no counterpart (yet)
(smoothed image)
(smoothed image)
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H.E.S.S. Highlight Resolved
Supernova-Remnants
SNR as cosmic particle accelerators Predicted
power law spectrum dN/dE E-22.2 Efficiency
10-50 Imaged using secondary gamma rays created
in interactions with ambient medium
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H.E.S.S. Highlight Resolved
Supernova-Remnants
? D. Berge, OG 22
RX J1713-3946
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Spectra
Preliminary
? Acceleration of primary particles in SNR shock
to well beyond 100 TeV

• Index 2.1 2.2
• Little variation across SNR
• Cutoff or break at high energy

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H.E.S.S. Gamma rays
ASCA X-rays
NANTEN CO at 1 kpc
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Primary population e or p ?
Electron model B 10 mG

• Need about 10 mG B field to match flux ratios
• Simplest electronic models dont work well

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RX J0852.0-4622 Vela Junior
Flux Crab Index 2.1 0.1
? N. Komin, OG 22
Feb. 2004 (3.2 h)
New 04/05 data
3D-Analysis Preliminary
ROSAT contours
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H.E.S.S. HighlightPulsar Wind Nebulae
Blondin et al. ApJ 563 (2001) 806

• Pulsar winds have modest energetics
• compared to SN ejecta, but
• most of the energy is in electrons
• radiative loss time scales for e are a few 1000
  y, versus 107 y for p

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H.E.S.S. HighlightPulsar Wind Nebulae
? B. Khelifi, OG 22
Vela X hard spectrum G 1.9 or G 1.5 ?
cutoff extends to 50 TeV no emission from
vela pulsar detected
Vela pulsar
ROSAT contours
Preliminary
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Another pulsar wind MSH 15-52
? B. Khelifi, OG 22
Contours Rosat Greyscale Radio
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HESS J1825-137
X-rays Gaensler et al.
TeV
? O. de Jager, OG 22
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H.E.S.S. HighlightDistant and Close Binaries
Mar 04
Douglas Gies (CHARA, GSU) William Pounds
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PSR B1259-63first variable galactic TeV source
? S. Schlenker, OG 22
HESS J1303-631
PSR B1259-63
early March 04
Apr./May 04
Feb. 04
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Distant and Close Binaries
? M. de Naurois, OG 22
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Microquasar LS 5039first detection of TeV
emission from a microquasar

• compact 4 (?) M? object in eccentric 4 day orbit
  around 20-30 M? star
• closest approach 1012 cm or 2 stellar radii

fueled by wind accretion(?)
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Spectral energy distribution

• Expect strong attenuation of gammas in photon
  field of massive star
• Hadronic component ?
• Orbital modulation ??

Index 2.12 0.15
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The centerof ourGalaxy
SNR G0.90.1
PWN
Sgr A East SNR ? Black hole ? DM Annihilation ?
GC
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Sagittarius A
syst. error
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Gamma ray spectrum
? L. Rolland, OG 22

• Power law, index 2.3
• No significant variability
• on year scale
• on month scale
• on day scale
• on hour scale
• on minute scale
• (in 40 h obs. time
• distributed over 2 years)

Preliminary
Preliminary
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Dark matter annihilation ?
Preliminary
proposed based on early H.E.S.S. data
proposed before H.E.S.S. data
? J. Ripken, OG 22
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H.E.S.S. HighlightGalactic center region
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H.E.S.S. HighlightGalactic center region
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H.E.S.S. HighlightGalactic center region
? J. Hinton, OG 21
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Diffuse emission from the GC ridge
Spectral index 2.29 0.07 0.20 Implies
harder CR spectrum than in solar neighborhood ?
Proximity of accelerator and target
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(subtracted)
gamma rays
CS
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Extragalactic TeV astronomy

• Physics of AGN jets
• Density of cosmological extragalactic background
  light (EBL)

EBL
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H.E.S.S. HighlightNew distant blazar sources
1ES 1101-232 z 0.186 12 s
Preliminary
H 2356-309 z 0.165 10 s
? S. Pita, OG 23 ? M. Tluczykont, OG 23
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Spectra ExtragalacticBackgroundLight
1 ES 1101 G 2.90.2
H 2356 (x 0.1) G 3.10.2
Preliminary
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Spectra ExtragalacticBackgroundLight
Source spectrum
? Upper limit on EBL
too much EBL
1 ES 1101 G 2.90.2
H 2356 (x 0.1) G 3.10.2
Preliminary
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Spectra ExtragalacticBackgroundLight
UV EBL
Not really a solution add huge amount of UV
photons to EBL ? problems with source
energetics, X-ray/gamma-ray SED ratio
too much EBL
1 ES 1101 G 2.90.2
H 2356 (x 0.1) G 3.10.2
Preliminary
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X
X
X
?
?
X
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Spectra ExtragalacticBackgroundLight

• EBL resolved
• Universe more
• transparent

X
measure- ments
upper limits
X
lower limits from galaxy counts
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Conclusion

• First H.E.S.S. results demonstrate that latest
  generation Cherenkov instruments have reached the
  critical sensitivity threshold
• Lots of interesting stuff out there hard
  spectra and extended sources
• Were looking forward to explore this domain
  further, together with CANGAROO, MAGIC, VERITAS,
  MACE
• See talks and posters (OG 21, OG 22, OG 23, OG
  27) for details on H.E.S.S. results, also
• M87 detection, PSK 2005, 2155 spectra, Crab, Mkn
  421,
• SNR, pulsar, microquasar, NGC253, limits,