Rene A. Ong (UCLA) 1The Universe Viewed in Gamma-Rays – Summary (2)Summary (2)Summary (2)Summary (2)The Universe Viewed in Gamma-RaysUniv. of Tokyo Workshop 2002Rene A. OngUniv. of California, Los AngelesRene A. Ong (UCLA) 2The Universe Viewed in Gamma-Rays – Summary (2)LOC, Mori, Yanagita, for inviting me.All speakers and contributing authors.Modern Computing … ?ThanksThanksThanksRene A. Ong (UCLA) 3The Universe Viewed in Gamma-Rays – Summary (2)Apologies, etc.Apologies, etc.Apologies, etc.Reviewing is not an easy business, so this talk will be far from perfect:• Mostly obs/exp - see also Summary(1).• Not comprehensive.• Subjective !• Concentrates on results presented here.Note: As many review talks as contributed papers. Will notredo all those nice presentations.But will try to go beyond a simple recap of meeting.Rene A. Ong (UCLA) 4The Universe Viewed in Gamma-Rays – Summary (2)OutlineOutlineOutline• Historical PerspectiveHow has the field changed recently?• Big ThemesWhere is the field going?• Selected New Results• Summary - Future• CommentsRene A. Ong (UCLA) 5The Universe Viewed in Gamma-Rays – Summary (2)Historical PerspectiveHistorical PerspectiveHistorical Perspective1990 1stsolid detection (Crab)1992 1stextragalactic (Mrk 421) TMACD I PalaiseauSuggestion – large TAs1993 TMACD II Calgary1994 TMACD III Tokyo (Kifune)1995 TMACD IV Padova1997 Mrk 501 FlaresTMACD V Kruger Park“Big Four” 3rdGen. DetectorsRene A. Ong (UCLA) 6The Universe Viewed in Gamma-Rays – Summary (2)Historical PerspectiveHistorical PerspectiveHistorical Perspective1999 TMACD VI Snowbird2002 KashiwaTMACD Conferences were important:• Marked separation of γ-rays from ICRC• Evolved - mix of reviews, theory/obs/detectorsIt would be nice to have a VHE γ-ray meeting every two years, whatever the name.Kashiwa Meeting has been in the spirit of this tradition. Consider trends since Snowbird. Also – see summary by Pohl at 27thICRC (Hamburg).Rene A. Ong (UCLA) 7The Universe Viewed in Gamma-Rays – Summary (2)Workshop Sub-Title IWorkshop SubWorkshop Sub--Title ITitle I(Towards a Major Atmospheric Cherenkov Detector VII)Not really this !Rene A. Ong (UCLA) 8The Universe Viewed in Gamma-Rays – Summary (2)Big ThemesBig ThemesBig Themes• Source Count increasing steadily.Rene A. Ong (UCLA) 9The Universe Viewed in Gamma-Rays – Summary (2)VHE Sky MapVHE Sky MapVHE Sky MapCas-AH1426+4281ES1959+65New Since 1999RX J1713-3946TeV J2032+4131NGC 253Rene A. Ong (UCLA) 10The Universe Viewed in Gamma-Rays – Summary (2)Source ListSource ListSource List1990-1999 1999-2002Solid (6) Crab H1426Mrk 421 1ES1959Mrk 501PSR 1706Likely (6) Vela Cas-A1ES2344 RXJ 1713SN1006 TeV J2032?? PKS 2155 NGC 253Cen X-33C 66ARene A. Ong (UCLA) 11The Universe Viewed in Gamma-Rays – Summary (2)Source NotesSource NotesSource Notes• At this meeting, CANGAROO reported a new source:NGC 253 (Starburst) – Itoh (S26)• And showed early evidence for possible sources:RCW 86 (SNR) – Watanabe (S32)RX J0852-4622 (SNR) – Katagiri (S19) Galactic Center – Tsuchiya (S17)• No confirmed detection of any SNR.• (Solid + Likely) = 12 Total VHE Sources.Rene A. Ong (UCLA) 12The Universe Viewed in Gamma-Rays – Summary (2)Hemisphere CountingHemisphere CountingHemisphere CountingQ: How does the S compare with the N?Hemisphere AGN Galactic UnknownN521S0 40• At present, statistics are still limited.• Future picture will look different:1. SNR detections will be confirmed.2. S Detectors improving dramatically.3. # of N Detectors is reducing.(TA, HEGRA, CAT…)Rene A. Ong (UCLA) 13The Universe Viewed in Gamma-Rays – Summary (2)Hemisphere CountingHemisphere CountingHemisphere CountingGalactic studies will gain in importance.SNRs, pulsars, EUIDs …Rene A. Ong (UCLA) 14The Universe Viewed in Gamma-Rays – Summary (2)Big ThemesBig ThemesBig Themes• Source Count increasing steadily.• S hemisphere will be increasingly importantfor field.• Multi-λ Approaches are essential.Spectral, temporal, spatial correlations.Rene A. Ong (UCLA) 15The Universe Viewed in Gamma-Rays – Summary (2)The X-ray - TeV γ ConnectionThe XThe X--ray ray --TeVTeVγγConnectionConnectionSNRs: Slane (01), Tanimori (02), Berezhko (03):• Importance of understanding the broadband SEDin SNRs and plerions. • SN 1006 – IC models look satisfactory.• In RX J1713 the situation is not clear at all.AGN: Coppi (07), Mukherjee (08):• In broad terms: x-ray and TeV data are correlated.Double-peaked SEDs, temporal relations.• Evidence for unified picture.• Look in detail: many complications. TeV blazars may be more tractable, interesting.Good time for X-ray work: Chandra, XMM/Newton, RXTE, (Astro 2E), etc.Rene A. Ong (UCLA) 16The Universe Viewed in Gamma-Rays – Summary (2)Allen 2000• Thermal electrons produce line-dominated x-ray spectrum withbremsstrahlung continuum• nonthermal electrons produce synchro-tron radiation over broad energy range• high energy tail of nonthermal electronsyields x-ray synchrotron radiation• nonthermal X-rays indicate presence of synchrotron nebula or high energyparticles accelerated in shock- either may be indicativeof potential γ-ray emissionSlaneRene A. Ong (UCLA) 17The Universe Viewed in Gamma-Rays – Summary (2)Allen 2000Slane• Spectrum of limb dominated bynonthermal emission- keV photons imply TeV 100≈eE• Chandra observations showdistinct shock structure in shell• Same region as TeV emissionSN 1006Rene A. Ong (UCLA) 18The Universe Viewed in Gamma-Rays – Summary (2)Allen 2000TanimoriSN 1006Naito et al. Astron. Nach. 320, 1999S = -2.2B ~ 4 µGEmax ~ 50TeVIC Modeling works!Rene A. Ong (UCLA) 19The Universe Viewed in Gamma-Rays – Summary (2)FSRQLBLHBLGrand Unified Blazar Scheme?=> L_x and L_gamma correlated!Add EGRETGamma-Ray Data …(synchrotron & Compton from SAME e+/e-?; 1?)peakLumγ−∝Donati et al. 2001(cf. Fossati el. 1998)CoppiRene A. Ong (UCLA) 20The Universe Viewed in Gamma-Rays – Summary (2)Allen 2000If electrons/pairs are primary particles, what is acceleration energy spectrum?Is the observed high energy cutoff in some objects intrinsic or simply due to photon-photon pair production (inside source or intergalactic)?What is the origin of the spectral breaks seen in X-rays/gamma-rays?What are seed photons for Compton upscattering??• Synchrotron Photons (SSC)• Accretion