6 th Rencontres du Vietnam: Particle Astrophysics Very High Energy (VHE) γ-ray Astronomy: Status & Future Rene A. Ong University of California, Los Angeles
OUTLINE Scientific Motivation Origin of cosmic rays A new Astronomy Beyond Standard Models. Experimental Technique Latest results from around the world Where do we go now? Next few years. Next decade. Conclusions Rene A. Ong (UCLA) Page 2
Cosmic Ray Origin 90 year old mystery! Galactic? Enormous E range Mostly charged particles E density ~ 1 ev/cm 3 Extragalactic? New component? Neutral messengers γ, ν required to directly observe cosmic accelerators. Diffuse, all particle spectrum (ν astronomy: DeYoung, Hoffman, Vernin, Weiler) Rene A. Ong (UCLA) Page 3
Galactic TeVatrons and PeVatrons Microquasars Pulsars Supernova Remnants (SNRs) Standard picture of SNRs: SN explodes into ISM. Diffusive shock acceleration. E, power-law form satisfied. Galactic Center Pulsar Nebulae But, no unambiguous evidence so far. Rene A. Ong (UCLA) Page 4
The VHE Sky 1995 3 sources Mrk421 Mrk501 Crab Pulsar Nebula SNR AGN Other, UNID R.A.Ong Aug 2005 Rene A. Ong (UCLA) Page 5
The VHE Sky - 2003 12 sources Mrk421 H1426 M87 Mrk501 1ES1959 Cas A 1ES 2344 TeV 2032 RXJ 1713 GC Crab PKS 2155 Pulsar Nebula SNR AGN Other, UNID R.A.Ong Aug 2005 Rene A. Ong (UCLA) Page 6
The VHE Sky - 2005 30 sources Mrk421 H1426 1ES 1218 1ES1959 Cas A 1ES 2344 Cygnus Diffuse TeV 2032 Mrk501 SNR G0.9 LS 5039 PKS 2155 Pulsar Nebula M87 RXJ 1713 GC H2356 PSR B1259 MSH 15-52 PKS 2005 AGN 1ES 1101 RXJ 0852 Vela X HessJ1303 Crab + 8-15 add. sources in galactic plane. SNR Other, UNID R.A.Ong Aug 2005 Rene A. Ong (UCLA) Page 7
Present Time: August 2006 35+ sources G. Hermann Rene A. Ong (UCLA) Page 8
Source Counts Source Type* Pulsar Wind Nebula (e.g. Crab, MSH 15-52 ) Supernova Remnants (e.g. Cas-A, RXJ 1713 ) Binary Pulsar (B1259-63) Micro-quasar (LS 5039, LSI +61 303) Diffuse (Cygnus region) AGN (e.g. Mkn 421, PKS 2155 ) Unidentified TOTAL * Includes likely associations of HESS unid sources. 2003 1 2 0 0 0 7 2 12 2006 6 6 1 2 1 13 6 35 Explosion in the number of VHE sources. Rene A. Ong (UCLA) Page 9
A New Astronomy New view of the Universe Many Surprises M87 Jet One example: Active Galactic Nuclei MAGIC Mrk 501 Central BH Supermassive BHs Jets beamed towards us Remarkable variability Rene A. Ong (UCLA) Page 10
Extragalactic Background Light (EBL) 2.7K M. Beilicke Determine cosmic IR/UV background Red shifted stellar light Red shifted dust light Rene A. Ong (UCLA) Page 11
Searching for Dark Matter Galactic Center Enhanced WIMP density in certain locations. WIMP annihilation γ, ν ν,ν γ continuum γ lines χ+χ p e d + Galactic Halo Galactic Satellites Extragalactic Sources Point back to source Search for excess components in cosmic rays (DIFUSION) γ-ray yields Rene A. Ong (UCLA) Page 12
Experimental Technique Rene A. Ong (UCLA) Page 13
HE and VHE γ-ray Detectors Satellite Detector Air Shower Detector Rene A. Ong (UCLA) Page 14
Cherenkov Telescopes γ ray θ ~ 1.5 o Rene A. Ong (UCLA) Page 15
MILAGRO Experimental World STACEE MAGIC TIBET MILAGRO CACTUS STACEE TACTIC TIBET ARGO-YBJ CACTUS PACT GRAPES TACTIC VERITAS HESS CANGAROO III Rene A. Ong (UCLA) Page 16
Scientific Highlights I. HESS Galactic Plane survey. Discovery of many new sources, many unidentified. II. III. IV. Detailed studies of Galactic sources: Supernova remnants. Pulsars and pulsar wind nebulae. Binary systems microquasars. Diffuse sources. Extragalactic Sources. AGN and Radio Galaxies (M87). New constraints on EBL. Dark Matter Searches: Galactic Center and dwarf satellites. Rene A. Ong (UCLA) Page 17
HESS Survey Gal. Centre 30 0 359 330 330 RX J1713.7-3946 Rene A. Ong (UCLA) Page 18
HESS Survey: New Sources HESS J1837-069 HESS J1825-137 HESS J1834-087 HESS J1813-178 HESS J1804-216 G0.9+0.1 Gal. Centre 30 0 359 330 330 Sources > 6 sigma (9 new, 11 total) HESS J1640-485 HESS J1614-518 RX J1713.7-3946 HESS J1616-508 Rene A. Ong (UCLA) Page 19
HESS Survey: New Sources HESS J1837-069 HESS J1825-137 HESS J1834-087 HESS J1813-178 HESS J1804-216 G0.9+0.1 Gal. Centre 30 0 LS 5039 HESS J1745-303 HESS J1713-381 HESS J1702-420 HESS 1632-478 HESS J1708-410 HESS J1634-472 359 330 Sources > 6 sigma (9 new, 11 total) Sources > 4 sigma (7 new) HESS J1640-485 HESS J1614-518 RX J1713.7-3946 HESS J1616-508 Rene A. Ong (UCLA) Page 20
Supernova Remnants RXJ 1713-3946 3946 SNR RXJ 1713-3946 RX J1713.7-3946 Berezkho & Völk astro/ph-0602177 ~B 2 d = 1 kpc E = 1.8. 10 51 erg M = 3.5 M ρ(r) = 0.01 10 /cm 3 B ~ 10 µg e/p = 10-4 HESS Image ASCA (X-ray) contours Good fit for this proton model but electron models are still possible. (U. Schwanke, parallel sessions) Rene A. Ong (UCLA) Page 21
Pulsar Wind Nebulae: Vela Region W. Hofmann Chandra X-rays Vela (Rosat) Vela X PWN Vela Junior d 200 pc age 700 y Rene A. Ong (UCLA) Page 22
µ Quasars: LSI +61 303 0.7 0.5 0.4 AU 0.9 0.3 To observer µ-quasar model 0.1 0.2 MAGIC High mass XRB @ 2kpc. Eccentric orbit, probably NS. Radio, X-rays modulated by orbital period of 26.5d. Compact jets resolved. MAGIC: Pt-like source, bright at phase [0.5,0.7]. Rene A. Ong (UCLA) Page 23
LS I +61 303: the movie Albert et al. 2006 Q: Are we seeing the jet or the disk? J. Rico Rene A. Ong (UCLA) Page 24
J. Hinton Diffuse VHE Sources Galactic Center and Cygnus HESS Galactic Center 1 degree H.E.S.S. 2004 50 hours Milagro Cygnus Region EGRET GeV Map underlay Preliminary Contours of CS emission (molecular tracer) Subtracted Image G. Sinnis TeV emission along Gal. plane. CRs interacting with molecular clouds. Evidence for new source of diffuse TeV radiation. CR interactions! Rene A. Ong (UCLA) Page 25
Extragalactic TeV Sources Now 12 known AGN (& M87) AGN are Blazars relativistic jet beamed to us 2 peak spectra Highly variable! MAGIC Mrk 421 and model fit. Looking out further in redshift. Rene A. Ong (UCLA) Page 26
Extragalactic Background Light upper limits X measurements X HESS limits lower limits from galaxy counts Reference shape Universe is more transparent! Rene A. Ong (UCLA) Page 27
Dark Matter I? DM annihilation 10-11 HESS Galactic Center. Results also from MAGIC. E 2 F(E) [TeV/cm 2 s] 10-12 10-13 20 TeV Neutralino 20 TeV KK particle 0,1 1 10 E [TeV] Astrophysics dominates but we don t know what it is! Rene A. Ong (UCLA) Page 28
Dark Matter II New result from STACEE (preliminary) Draco Dwarf Satellite CACTUS (2005) Claim evidence for 100 GeV γ-rays from Draco. 2.4 hr data. Large γ-ray excess. 10.2 hr data, Apr-Jun 2006. No γ-ray signal. Rate, R < 0.085 γ/min (95%). Flux (>200 GeV) < 1.9 x 10-11 /cm 2 /s CACTUS also now sees no signal. (Tripathi, ICHEP 2006) Rene A. Ong (UCLA) Page 29
Upcoming Projects Rene A. Ong (UCLA) Page 30
VERITAS 12 m diameter reflector 499 PMT camera Event in Camera Steel OSS Control Room VERITAS Arizona, USA Similar to HESS: 4 x 12m Telescopes 500 element cameras, 3.5 o 500 MHz FADC on each pixel. Rene A. Ong (UCLA) Page 31
VERITAS: 2 Telescope Operation γ-rays VERITAS Event April 2006 Strong γ-ray signal: Mrk 421, 4 hr data, 30 σ, ~6 γ/min (not optimized) (Whipple 10m: 1.8 γ/min) Mrk 421 Image Rene A. Ong (UCLA) Page 32
VERITAS: Array Completion Tel 3 Tel 4 110m Tel 1 80m Tel 2 Telescope 4 July 2006 Whipple Base Camp July 2006 1350m, dark site Oct 2006: 3 Telescope operation: Science observations begin. Feb 2007: 4 Telescopes! Rene A. Ong (UCLA) Page 33
MAGIC II and HESS II MAGIC-I MAGIC-II II MAGIC-II (2007) 85m Second 17m telescope. High-QE camera. (F. Goebel, parallel session) HESS-II (2008) New 28m telescope. 2048 pixel camera. Lower energy ~50 GeV. (J.P. Tavernet, next talk) Rene A. Ong (UCLA) Page 34
GLAST Satellite Telescope GLAST LAT: Si strip tracker. CsI calorimeter. Energy range 0.03-300 GeV Simulated sky map from 1 year survey. Scheduled launch: Sept. 2007. GLAST will have a huge impact on the field. Rene A. Ong (UCLA) Page 35
Future Directions GLAST A. Konopeloko 10-100 GeV 100 GeV 10 TeV 10 100 TeV AGNs Pulsars & PWN Cosmology HESS, VERITAS CANGAROO III MAGIC SNRs Origin of cosmic rays Dark matter Better sensitivity! Wider FOV GRBs There is a wide variety of opinion on what direction(s) to pursue. Rene A. Ong (UCLA) Page 36
Future Concepts mini-hawc mini-hawc: Air shower detector: wide FOV and good duty cycle. Moderate sensitivity & resolution. Energy E > 500 GeV. minihawc: 841 PMTs (29x29) 5.0 m spacing Single layer with 4m depth Instrumented Area: 22,500 m 2 PMT spacing: 5.0 m Rene A. Ong (UCLA) Page 37
Future Concepts Large Cherenkov Tel. Arrays S. Fegan Field of view [π sr] Field of view [deg] Collecting Area [km 2 ] HE-ASTRO: 217 Telescopes (ø10m), 80m separation. 1.1 km 2 collection area & 12 o FOV. Challenging! Also, detailed work in Europe and Japan. Cherenkov Telescope Array (CTA) concept well underway. Rene A. Ong (UCLA) Page 38
The VHE γ-ray Science Program M. Martinez SNRs Origin of Cosmic Rays Pulsars Microquasars AGNs Cold Dark Matter cosmological γ-ray Horizon Test of the speed of light invariance GRBs Rene A. Ong (UCLA) Page 39
SUMMARY New generation of Cherenkov telescopes has yielded outstanding results many new sources discovered in last two years an unprecedented increase. Galactic Plane is rich in the number and type of VHE sources. Pulsar nebulae and SNRs are both firmly established in the TeV band. Origin of CR s is still an important question. New discoveries increase the number of known TeV blazars and push further out in redshift. Universe is more transparent than expected. No real evidence for DM from TeV γ-ray measurements, but technique is a key complement to direct and LHC. Upcoming experiments on ground (VERITAS) and in space (GLAST) should continue the rapid development of VHE astrophysics. Others will follow! Rene A. Ong (UCLA) Page 40
Acknowledgements Much thanks to: D. Driscoll, W. Hofmann, S. Fegan, A. Jarvis, A. Konopelko, R. Mirzoyan, M. Punch, G. Sinnis, J.P. Tavernet, M. Teshima, & M. Tripathi Rene A. Ong (UCLA) Page 41