Results from VERITAS Tel 4 Tel 2 Tel

Results from VERITAS Tel 4 Tel 2 Tel 3 New Opportunities at the interface between particle physics and astronomy VERITAS Tel 1 Frank Krennrich*, for the VERITAS Collaboration (*Iowa State University)

Outline • VERITAS Instrument Performance • Northern Sky seen in the first year • Extragalactic science • Summary

E ~ 100 Ge. V - 50 Te. V Aarea ~ 105 m 2 ang. Res. ~ 3’ - 6’ Energy Res. ~ 15% FOV ~ 3. 50 Very Energetic Radiation Imaging Telescope Array System

VERITAS Collaboration U. S. Adler Planetarium Argonne Nat. Lab. Barnard College De. Pauw U. Grinnell College Iowa State U. Purdue U. Smithsonian UCLA UCSC U. Of Chicago U. of Delaware Univ. of Iowa U. of Massachusetts U. of Utah Washington U. Canada Mc. Gill U. K. Leeds U. Ireland Cork Inst. Tech. Galway-Mayo Inst. N. U. I. , Galway U. College Dublin + 25 Associates Supported by: SI, NSF & DOE (US), PPARC (UK), NSERC (Canada), SFI (Ireland) VERITAS-4 Construction funded in 2003

VERITAS Observatory T 2 Spring 2006 T 3 Fall 2006 T 4 Spring 2007 T 1 Jan 2005

Te. V Monitoring capability 7 km

VERITAS Telescope Co Ro ntr om ol Davies-Cotton f/1. 0 Optics. Total area=110 m 2

VERITAS Telescope Co Ro ntr om ol Davies-Cotton f/1. 0 Optics. Total area=110 m 2

Stereoscopic Events

Angular Resolution o Courtesy Asif Imran

VERITAS Sensitivity 5σ Detection Sensitivity 1% Crab in 47 hours 5% Crab in 2. 5 hours • Measured sensitivity to the Crab Nebula at high elevation (>65°) • HESS ~ 1% Crab in 25 hours • MAGIC ~ 2% Crab in 50 hours

Te. V -ray Sky W Comae Mrk 421 1 ES 1218+304 Mrk 501 M 87 1 ES 0806+524 LSI +61 303 IC 443 Crab Nebula Cas A 1 ES 2344+514

Key Science Questions • Origin of Cosmic rays - galactic/Extragalactic • Relativistic Jets & Black holes - leptonic vs. hadronic jets • Dark Matter - Neutralino Annihil. Signature - LHC - direct detection - Storage • Te. V beam in extragalactic space - test dispersion relation of light - Q. G. - how far do we see? Opacity? - Probe Cosmic Infrared Background

Science Program Observations: ~ 800 hrs / year + ~ 200 hrs / year moonlight Bulk Program (40%) Science Groups: Astroparticle Physics Blazars Dark Matter Extragal. Sources Galactic Compact Galactic Diffuse GRB’s PWN & SNR’s Unidentifieds Discretionary (10%) To. O’s GRB’s (priority) etc. Key Science Projects (50%) Sky Survey (Cygnus region) BLAZARS SNRs/PWN Dark Matter

Extragalactic Science recent discoveries Multiwavelen Science EBL

1 ES 0806+524 ATEL#1415 r a in Pr m i l e y - “best candidate” Te. V BL Lacs (Costamante & Ghisellini 2002) - HBL - z = 0. 138 - 5. 8 in ~ 40 hours - flux ~ 0. 01 Crab - weakest VERITAS blazar P. Cogan, in preparation

W Comae ATEL#1422 - radio 1971, X-ray 1980 - IBL (between LBL- HBL) - seen by EGRET: 0. 1 -10 (27) Ge. V - z = 0. 102 - 4. 9 in ~ 40 hours - outburst March 08 (> 8 detection) - Quasi-simulataneous Courtesy of M. Beilicke X-ray data (Swift)

W Comae Courtesy of M. Beilicke

W Comae Courtesy of M. Beilicke

W Comae Courtesy of M. Beilicke

W Comae - one-zone SSC/ weak B-field - EC model/ B ~ 0. 3 G - Ge. V/Te. V obs. critical Quasi-simultaneous data March 14/15 2008 from AAVSO, UVOT, XRT, VERITAS

M 87 HST M 87 - Giant elliptical Galaxy - D ~ 16 Mpc - Misaligned jet (<20 o) - First non-blazar VHE source outside galaxy - Candidate UHE cosmic ray accelerator - Synch. X-ray source -> E >10 Te. V electrons - close up view of a jet! 4 evidence (HEGRA 03)

M 87 - UHE cosmic rays? - Synchr. Proton Blazar? p π g 0 g + - Synchr. Self Compton - inv. Compton in kpc jet (no time variations) - annihilation of SS dark matter - Where do Te. V photons originate?

M 87 - M 87 under the “microscope” in radio-optical-X-ray - variable in X-rays - Te. V “image” is not resolved 15 “ 80 pc

M 87 - M 87 under the “microscope” in radio-optical-X-ray - variable in X-rays - Te. V “image” is not resolved 15 “ 80 pc

M 87 VHE/X-ray Long-Term Correlation Acciari et al. (VERITAS collaboration), Ap. J, 679, 1427 (2008) VHE/X-ray Short-Term Correlation Hui et al 2008 (VERITAS collaboration), in preparation

M 87 VHE/X-ray Long-term Light Curve � Joint campaign HESS/MAGIC/VERITAS > 120 h in 2008 Stay tuned! � Hui et al 2008 (VERITAS collaboration)

1 ES 2344+514 - HBL - z = 0. 044 - discovered 1995 by Whipple - 0. 07 Crab - VERITAS Observations Oct. 07 - Jan. 08 - 20. 5 detection - Swift: highest known X-ray flux on Dec. 8 07 - VHE flux on Dec. 6/7 07: 0. 41 Crab

Mrk 421 - HBL - z = 0. 031 - “old faithful” - Early 2008: 0. 3 - 10 Crab - Te. V monitor of transients ATEL#1506

1 ES 1218+30. 4 Courtesy of P. M. Fortin Beilicke z=0. 182

Probing Cosmology Blazar: DN/DE ~ E-2 E ~ 1 Te. V Absorption: exp (- (E�� )) e+ e- Measured Spectrum: d. N/d. E ~ E-2 exp(- (E�� )) Nikishov, JETP, 14, 2 (1962) Gould & Schreder, Phys. Rev. 155, 1408 (1967) Stecker, de Jager & Salamon, Ap. J, 390, L 42 (1992) ~ 1 e. V

Te. V Data - blazars with sufficient redshift - good spectral data - sensitive to near and/or mid-IR VERITAS 1 ES 1218+30. 4 (HBL) Z = 0. 182 E ~ 0. 2 - 1. 5 Te. V 3 o HESS Aharonian et al. 2006, 2007. 1 ES 1101 -232 (HBL) Z = 0. 186 E ~ 0. 2 - 2. 9 Te. V 1 ES 0229+200 (HBL) Z = 0. 1396 E ~ 0. 5 - 11. 2 Te. V

Constraints to Intrinsic Spectra New Lower limit from galaxy counts Taking into account Fuzzy fringes of galaxies Levenson & Wright 2008 For a given measured Blazar spectrum a Higher EBL implies a Harder intrinsic spectra! Slope of EBL spectrum is Critical for constraining Intrinsic spectrum! Levenson & Wright, ar. Xiv: 0802. 1239 v 2

Constraints to Intrinsic Spectra

Constraints to Intrinsic Spectra

Constraints to Intrinsic Spectra

Constraints to Intrinsic Spectra

EBL Lower Limits & Blazar Spectra Te. V blazars seem to exhibit extremely hard spectra d. N/d. E ~ E-1. 28+-0. 20 or harder! FK, Dwek & Imran, submitted to Ap. J

Summary • VERITAS Performs well! 0. 01 Crab (47 hr); ang. Res. ~ 0. 1 deg. • Seen ~ dozen sources in the Northern Sky • Broad Science program • Detailed studies of M 87 • Discovery of W Comae; study of IBLs • Hard spectra of distant blazars • EBL studies