1. 1 VERY ENERGETIC RADIATION IMAGING TELESCOPE ARRAY SYSTEM VERITAS Mark Lang, National University of Ireland, Galway

2. 2 VERITAS Organization Teaming Agreement Collaborators Teaming Agreement Collaborators Iowa State University Adler Planetarium Iowa State University Adler Planetarium Leeds University Barnard College Leeds University Barnard College McGill University DePauw University McGill University DePauw University National University of Ireland, Dublin Grinnell College National University of Ireland, Dublin Grinnell College Purdue University U.C. Santa Cruz Purdue University U.C. Santa Cruz Smithsonian Astrophysical Observatory U. Mass. Smithsonian Astrophysical Observatory U. Mass. University of California, Los Angeles N.U.I., Galway University of California, Los Angeles N.U.I., Galway University of Chicago Cork I.T. University of Chicago Cork I.T. University of Utah Galway-Mayo I.T. University of Utah Galway-Mayo I.T. Washington University, Saint Louis Argonne National Lab. Washington University, Saint Louis Argonne National Lab. Funding from NSF/DOE/Smithsonian/PPARC/SFI/NSERC The VERITAS Collaboration Project Office: Whipple Observatory, SAO (Managing Organization)

3. 3 VERITAS – UK Leeds: Stella Bradbury, Michael Hillas, Johannes Knapp, Jeremy Lloyd-Evans, Joachim Rose Oxford: (Associate) Ignacio de la Calle Perez

4. 4 VERITAS – Ireland UCD: John Quinn NUI Galway: Gary Gillanders, Mark Lang Galway-Mayo Inst. Tech.: Pat Moriarty Cork Inst. Tech.: Josh Reynolds

5. 5 VERITAS – Ireland Data Acquisition Software Data Analysis Software Optical alignment Sky-clarity monitoring 10m AGN monitoring

6. 6 Whipple Base camp site 1967-8 InIn

7. 7 VERITAS 2007 VERITAS 2007 Instrument: ● Four 12-m telescopes ● 500-pixel cameras (3.5° FoV) ● FLWO, Mt. Hopkins, Az (1268 m) ● Completed Spring, 2007

8. 8 Specifications: ● Energy threshold ~ 150 GeV ● Source location < 0.05° ● Energy resolution~ 10-20 % ● Sensitivity (crab)~ 31  hr -½

9. 9 Kitt Peak Site (Horseshoe Canyon).

10. 10

11. 11

12. 12 85 m 109 m 85 m 35 m T1 Fall 2006 January 2007 T4 T2 T3 Since January 2006 VERITAS-4 at the Whipple Observatory

13. 13 Crab Signal as seen in VERITAS in real time VERITAS: 31 sigma in one hour of data taking

14. 14 Sources detected by VERITAS (as of November, 2007) GALACTIC GALACTIC Crab Nebula (plerion) Crab Nebula (plerion) LSI +61 303 (binary)* LSI +61 303 (binary)* IC433 (SNR) IC433 (SNR) Cas A (SNR) Cas A (SNR) MGRO J1908 (dark) MGRO J1908 (dark) EXTRAGALACTIC EXTRAGALACTIC Mrk 421 (blazar) Mrk 421 (blazar) Mrk 501 (blazar) Mrk 501 (blazar) H1426+42 (blazar) H1426+42 (blazar) 1ES2344 (blazar) 1ES2344 (blazar) 1ES1218 (blazar) 1ES1218 (blazar) M87 (radio galaxy)* M87 (radio galaxy)* RGB0152+017 (blazar) RGB0152+017 (blazar)

15. 15 LS I +61 303: Binary

16. 16 VERITAS Detection of LS I+61 303: 40.8 hr of data: Oct. ’06 – Jan. ’07 Two/three telescopes Significance = +8.6 σ Mean rate = 0.24 +/- 0.03 γ/min

17. 17 Active X-ray Regions Active TeV regions VERITAS

18. 18 44 h of 3-telescope observations elevations from 55 o to 71 o 5.1 σ, Rate of ~0.1 γ/min ~1.7% of Crab Nebula flux (E>250 GeV)

19. Tubac, April 27, 2007 TeV Variability of M87 VERITAS HESS constant flux fit: χ 2 = 21.4/22

20. 20 X-ray/TeV gamma-ray

21. 21 VERITAS Observing Program Allocation of time Allocation of time Key Science Projects (50%) Key Science Projects (50%) Scheduled by TAC (35%) Scheduled by TAC (35%) Director’s Discretionary (15%) ToO and Engineering Director’s Discretionary (15%) ToO and Engineering Key Projects: Key Projects: Sky Survey (130 hours) Sky Survey (130 hours) AGN (110 hours) AGN (110 hours) SNR (100 hours) SNR (100 hours) Dark Matter (60 hours) Dark Matter (60 hours) Guest Observer Program Guest Observer Program Strong Associates Program Strong Associates Program No formal GI program No formal GI program

22. 22

23. 23 End