Scientific Highlights from AGN Observations with the MAGIC Telescope Robert Marcus WAGNER Max-Planck-Institut für Physik, München on behalf of the MAGIC COLLABORATION
MAGIC Major Atmospheric Gamma-ray Imaging Cerenkov Telescope 17m diameter Imaging Air Cerenkov Telescope: currently largest single-dish instrument 3.5 diameter FOV photomultiplier camera with 576 enhanced-qe PMTs Trigger threshold: 50 GeV 60 GeV at zenith Sensitivity: 1.6% Crab Nebula in 50 hours above E=270 GeV (enhanced by timing information from new 2 GSample/s FADC) γ-psf is about 0.1 Enhanced duty cycle (moon +twilight observations) R. Scientific Highlights from MAGIC Observations R. M. M.Wagner: Wagner: Scientific Highlights fromagn MAGIC AGN Observations
TeV Blazars Extragalactic VHE! -ray sources Blazars: Jets viewed under small angle Strong nonthermal radiation High variability at all wavelenghts High Doppler factors expected: Jets may attain high luminosities γ-rays are messenger particles, may allow to probe properties of: Leptonic acceleration in the jets Hadronic acceleration } (E!>0 GeV) 21 n4 Mk 180 kn + M 1 1 71 + 6 071 S5 50 9+6 195 142 6+4 28 24 6+5 080 +180 o M 01 155 04 8+3 121 e ma W Co 496 5 kn o M8 7 279 ) 3C 0.536 (z= 13 3+1 32 1-2 1 o 14 4+5 L Lac 234 B -180 200 00 9+2 022 215 5-3 23 Objects 054 22 8-3 04 121 7034 17 2+0 015 89 5-4 6-3 235 09-90o 13 detected by MAGIC 6 first-time detections Recent additions discussed here: 2008-06-24 - Up-to-date plot available at http://www.mppmu.mpg.de/~rwagner/sources/ 3C 279, 1ES 11+496, S5 0716+714 hadronic model Kino et al. Inverse synchrotron peak Buckley 99 Compton peak 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Redshift z Active Galactic Nuclei: Extragalactic objects Small fraction of observed galaxies Harbor supermassive black holes of 6 solar masses Rotating accretion disk Emission of collimated, relativistic jets +90
Northern Blazar Multi-Wavelength Campaigns Simultaneous Multifrequency Observations SEDs spanning over > 15 orders of magnitude VHE: HESS, MAGIC X-ray: Suzaku, Swift Optical: KVA Multi-Wavelength Campaigns in 2006/7 on Mkn 421 April 06: clear detection in all instruments Mkn 501 July 06: lowest VHE state ever observed (MAGIC, Suzaku, KVA) 1ES 1218+304, 1H 1426+428: significant X-ray variability, VHE still under study PG 1553+113 July 06: No significant variability, first MWL campaign, VHE compatible with earlier measurements Multi-Wavelength campaings successfully conducted Analyses of 1ES 1218+304 and 1H 1426+428 finished soon Further campaigns organized SED Mkn 501 lowest VHE state ever
1ES1959+650: Suzaku, Swift, & MAGIC Tagliaferri et al. + MAGIC ApJ 679 (2008) 29 Multi-Wavelength campaign in May 2006 Swift-XRT nights, Suzaku 2 nights Suzaku/Swift in good agreement Relatively high X-ray/optical flux, X-ray peak: shifts with increasing flux 14.3h VHE data: among lowest VHE flux (60% of low flux measured by MAGIC 2004) Spectral Energy Distribution γ-ray light curve MAGIC Modeling: One-zone SSC w.r.t. 2002-SED: similar parameters source slightly more compact (7.3 x 15 cm), magnetic field slightly lower (0.25 G) Doppler factor identical (D=18) Differential Energy Spectrum
Energy-Delayed Flare Mkn 501 MAGIC Collab. ApJ 669, 892 & arxiv:0708.2889 Observed 2 flares in July 2005 from bright blazar Mkn 501, 4-Crab level (Albert+07a) 2005 July 9: Delayed observation of high energies in the flare Quantification of the Delay: ECF: Maximize intrinsic power of flare (Albert+07b) Likelihood Function Fit (Martinez & Errando 2008) Measured delay: (0.030±0.012) s/gev Zero-delay probability P=0.026, effect marginal Interpretation of the Observed Delay: 150-250 GeV 250-600 GeV 1. Gradual inefficient acceleration of electrons acceleration efficiency: ξ -5 (Albert+07) 2. Gradually-accelerated blob model clear prediction for GLAST+IACT MWL 3. Extrinsic propagation effect attributed to Lorentz invariance violation Poster #45: RMW & Bednarek 600-1200 GeV delay implies QG energy scale 0.4 x 18 GeV but delay marginal: probing the Planck mass scale MQG > 0.21 x 18 GeV (95% CL) > 1200 GeV
M87: A Giant in Our Backyard Peculiar VHE source: Radio galaxy, non-blazar Misaligned Blazar Jet seen under an angle of 30 Jet clearly visible, resolved jet morphology. Close! Only 16 Mpc away. Source of UHECR? VHE Detections by HEGRA, H.E.S.S., VERITAS /s) ( -9 /m 2 Φ >730GeV 20 HEGRA 15 5 0 H.E.S.S. VERITAS 2000 2002 2004 2006 2008 Acciari+08 Radio VLBA 8 GHz HST-1 Harris+07 nucleus knot D knot A X-rays Chandra X-rays: HST-1 sometimes brighter than nucleus Poster #156: Fast variability Knot A as VHE source excluded Beilicke et al. Collaborative VERITAS/MAGIC/H.E.S.S. monitoring aiming at good TeV coverage, Organized schedule, Data exchange, Chandra & Swift coverage, 120h in 2008
M87: Strong Flaring in M87 Beginning of 2008: Nucleus bright in X-rays (at all-time high), while HST-1 rather dim (courtesy D. Harris) 8 σ on 2008 Feb 1: Trigger issued to H.E.S.S./VERITAS 150-350 GeV 9.9 σ in overall sample (22.8 h) 2008 Jan 30-Feb 11, including moon and twilight data VHE Flux variable 3%-15% Crab, Apparent & high variability >350 GeV Confirming day-scale variability (5.6 σ) Compatibility with const. 150 350 GeV Marginal: spectral hardening? constant flux MAGIC Collab. ApJL subm., arxiv: 0806.0988 Poster #137: Mazin,RMW et al. (Crab nebula) >350 GeV α= 2.2 α= 2.6 day-scale : 5.6 σ
Do Optical Triggers Work? Regular optical monitoring of candidate sources, e.g.: Mkn 180 Trigger point MAGIC Collab., ApJ 648 (2006) L5, ApJ 667 (2007) L21 March 2006 MAGIC 12.1 h S=5.5 σ Optical light curves: KVA telescope, La Palma 1ES 11+496 Trigger point MAGIC 2006 MAGIC 2007 MAGIC 18.7 h S=6.2 σ March-May 07 Soft spectrum: Γ=3.3 after EBL deabsorption % Crab at 200 GeV No significant variability 3 σ in 2006 data. If 2006 signal genuine, then 50% lower flux than in 2007 1ES 11+496 From the optical spectrum we determined the redshift to be z = 0.212 ± 0.02 Third-most distant VHE γ-ray source
A Continuing Success Story... MAGIC Collab., Atel #1500 Optical light curve: KVA telescope, La Palma S5 0716+714 MAGIC PRELIMINARY KVA R-band optical Significance 6.8 σ Known blazar with unknown redshift October/November 2007: X-ray outburst, detected by Swift April 17, 2008: Optical flux doubled within three nights April 22, 2008: MAGIC observations commence Optical trigger on S5 0716+714: MAGIC observations in 2008 April 2.6h of data, clear signal (6.8 σ): discovery! April 28: Swift reports F(0.3- kev) = 4x -11 erg/cm²/s, about 50% larger than that observed in 2007 Apr 29: ATel #1500, MAGIC reports 6.8σ discovery Apr 23-25 F(>400 GeV) -11 ph/cm²/s ( 25% Crab) 3rd low-peaked VHE Blazar after BL Lac & W Comae Host galaxy detected: z=0.31±0.08 (Nilsson+08) Have taken further data analysis in progress Poster #25: Lindfors & Mazin
3C 279: A Famous Blazar Flat Spectrum Radio Quasar at z=0.536 Apparent luminosity 48 erg/s Brightest EGRET AGN (Wehrle+97,98) Gamma-ray flares in 1991 and 1996: High dynamical range in EGRET data Fast time variation: ΔT ~ 6hr in 1996 flare No strong emission lines: Appears like BL Lac during high optical epochs (Wehrle+98) R. M. Wagner: Scientific Highlights Highlights from MAGIC from AGN MAGIC Observations AGN Observations x0 MAGIC Observations: 2006 January April during WEBT campaign 9.7 hrs in nights Detection in 2 nights s -1 ] -2 Integral flux (0-500 GeV) [cm 0.6 0.5 0.4 0.3 0.2 0.1 0-0.1-9 Counts 140 120 0 80 60 40 20 0 MAGIC Collab. Science 320, 1752 23 Feb 2006 22 Feb 2006 6.2σ 2.2σ Flux incompatible with const.: 5.04 σ Contrib. Talk: Errando 180 ALPHA Plot 160 23 February 2006 166±28 Excess Events 6.2 Standard Deviations 0 20 30 40 50 60 70 80 90 ALPHA [deg] -0.2 760 770 780 790 800 8 820 830 Time (Julian Date 2453000)
νi 3C 279: Implications for the EBL EBL influences observed spectrum, resulting in an exponential decrease at high energies & cutoff We reconstruct intrinsic spectrum along EBL models Stecker+07, Primack+05, Kneiske Stecker fast-evolution: α*=0.5±1.2 Kneiske (tuned): α*=1.5 Primack: α*=2.9±0.9 High EBL difficult to reconcile with Blazar acceleration models Overall energetics 3C 279: No strong emission lines Assume α*=1.5 reasonable Infer gamma-ray horizon (Kneiske tuned) Allowed region for EBL rather small Probe back to z=0.536 HST and Spitzer may correctly estimate EBL Contrib. Talk: Errando s -1 ] cm -2-1 differential flux, dn/de [TeV probing 0.2-2μm ) -1 sr -2 (nw m ν -6-7 -8-9 - -11-12 2 α=4.1 fit to measured spectrum: -α dn/de = N E 0 200GeV - = (5.2 ± 1.7) [TeV N 0 α = 4.11 ± 0.68 1-1 1 MAGIC Collab. Science 320, 1752 3c279, measured systematic error band EBL-corrected, Primack, α* = 2.94 ± 0.91 EBL-corrected, Stecker (fast), α* = 0.49 ± 1-1 cm -2 s -1 ] 70 80 0 200 300 400 500 Energy, E [GeV] Stecker et al., 2006, (fast evolution) max-ebl (this work) Primack et al., 2005 Cosmic Microwave Background Mazin & Raue, upper limit 2007 HESS upper limit, 2006 2 3 λ (µm)
Summary & Conclusions There are now 23 AGNs observed in E>0 GeV γ-rays, mostly (18) high-peaked BL Lac objects Delay in a VHE flare in Mkn 501 Different models to explain delay Now reaching much further in redshift 3C 279 & S5 0716+714 Non-HBLs: BL Lac, S5 0716+714 (MAGIC), W Comae (VERITAS), 3C 279 (FSRQ, MAGIC 2006) First FSRQ in TeV gamma-rays: All source classes of the blazar sequence detected in VHE very distant, important input for EBL! and M87 (2008 shared HESS/VERITAS/MAGIC campaign) day-scale variability on the way to identifying the TeV engine in M87 Successful optical triggers lead to discovery of Mkn 180 (2006), and far-away 1ES11+496 (z=0.212, 2007) & S5 0716+704 (z=0.31±0.08, 2008) MWL on Northern TeV Blazars Mkn 501, Mkn 421, PG 1553+113, 1ES 1959+650 analyzed 1H 1426+428, 1ES 1218+304 under analysis
Outlook Novel trigger concept: Sum-trigger Further lower analysis threshold, also for AGNs Contrib. Talk: Schweizer MAGIC-II operational second half of 2008 (Inauguration 18 19 Sep 2008) Improvement of sensitivity (up to factor 3) Great time for AGN physics! MAGIC AGN-related contributions: - Errando 3C 279 (oral Tuesday) - Mazin+, Beilicke+ M 87 #156 - Lindfors+Mazin: Optical ToO #25 - Hadasch+ PKS 2155-304 #95 - Berger+ BL Lacertae #118