Results from Galactic Source Observations with VERITAS Amanda

Results from Galactic Source Observations with VERITAS Amanda Weinstein for the VERITAS Collaboration Moriond, Feb. 4, 2009 A. Weinstein 4 Feb 2009 – Moriond

Outline q Introduction to VERITAS q VERITAS Galactic Science Program Overview Highlight results q Summary and future prospects A. Weinstein 4 Feb 2009 – Moriond 2

VERITAS at Whipple Observatory Data, October 2007 -June 2008: ● Good weather, 4 -telescopes ~800 hours ● Moonlight ~100 hrs → ~35% moonlight data this fall T 2 109 m Fall 2006 Since March 2006 85 m T 3 82 m 35 m T 4 T 1 April 2007 ● FLWO, Mt. Hopkins, Az (1268 m asl) Specifications: ● Angular resolution ● Energy resolution A. Weinstein ~ 0. 1° ~ 15 -20 % 4 Feb 2009 – Moriond Sensitivity: ● 1% Crab @ 5 s ● 5% Crab @ 5 s ~ 47 hrs ~ 2. 5 hrs 3

VERITAS Galactic Science Program SNR/PWN Key Science Project Composite and shell-type SNR Strategy: search for Te. V PWN associated with pulsars E/d 2 > 1 x 1035 ergs/s/kpc 2 Cygnus Region Sky Survey (Key Science Project) e. g. HMXBs, LMXBs, magnetars (microquasars) Combination of dedicated and serendipitous observations (objects in FOV of other targets, survey) Galactic Compact Objects A. Weinstein 4 Feb 2009 – Moriond Dark accelerators… Unidentified Objects 4

Galactic Science LSI 61+303 MGRO J 1908+06 AGILE 2021+4024 PSR J 1740+1000 PSR J 0205+6449 IC 443 Geminga PSR J 0631+1036 Crab Cas A A. Weinstein 4 Feb 2009 – Moriond 5

Cas A q Young (330 yrs) SNR at a distance of ~3. 4 kpc q Massive star progenitor q 5’ (4. 5 pc) diameter (comparable to Te. V angular resolution) q Discovered in Te. V by HEGRA (232 hrs, 5 s), confirmed by MAGIC (47 hrs, 5. 3 s) Flux ~ 3. 3 % Crab above 1 Te. V Power-law index of 2. 3 ± 0. 2 stat ± 0. 2 sys q Well studied SNR in a relatively clean environment q Extensive modeling of cosmic-ray acceleration and gamma-ray production exists A. Weinstein 4 Feb 2009 – Moriond q VERITAS: wobble-mode observations, 0. 5º offset, during Oct/Nov 2007 with 4 telescopes q Exposure: 20. 3 hr: 9. 8 s detection q Flux: ~ 3% Crab q Consistent with a point source 6

IC 443 q Middle-aged SNR ~ few – 10 kyr q SNR shell / molecular cloud interaction (beam dump) q PWN (southern edge): spin-down luminosity uncertain (1036 erg/s – 5 x 1037 erg/s) • Green – Radio • Red – Optical • Blue – X-rays VERITAS position PR EL IM IN A R Y q Co-discovered (MAGIC/VERITAS) in Te. V in 2007 q Observed (wobble, 0. 5º offset) during two epochs, for 37. 1 hrs total livetime: Feb / Mar 2007 with 3 telescopes, PWN location Oct / Nov 2007 with 4 telescopes Ø Center of Feb/Mar hot spot: Ø 06 16. 9 +22 33 PWN A. Weinstein 4 Feb 2009 – Moriond q Flux ~3% Crab q 8. 2σ peak significance pre-trials 7

IC 443 2 -D Gaussian profile fit Centroid: 06 16. 9 +22 32. 4 ± 0. 03º(stat) ± 0. 07º(syst) Extension: σ ~ 0. 17º ± 0. 02º(stat) ± 0. 04º(syst) q. Not coincident w/radio/optical shell to northeast q. Overlap with CO indicating molecular cloud along line of sight q. Maser emission suggests SNR shock interacting with cloud q. Te. V emission could be CR-induced pion production in cloud(1, 2) associated with the pulsar wind nebula to the south (3) – Moriond A. Weinstein 4 Feb 2009 (relic electrons? ) (1) Zhang, L. and Fang, J. Ap. J. 675 L 21 (2008). (2) Torres, D. F. et al. ar. Xiv: 0804. 2526. (3) Bartko, H. and Bednarek, W. ar. Xiv: 0712. 2964. Elongation along cloud 8

LSI 61+303 J. Casares et al (MNRAS 360, 1105 (2005)) MW: Fermi ~25 hrs ~21 hrs Microquasar? ~45 hrs 50% moonlight data VERITAS: phases 0. 2 -0. 9 MW: Swift/RXTE MW: Swift, RXTE Binary pulsar? A. Weinstein 4 Feb 2009 – Moriond 9

LSI+61 303: 2006 -2008 RXTE(2 -10 ke. V) SWIFT(0. 2 -10 ke. V) 2006 -2007 -2008 7. n 3σ tio ec de te ct σ io n 4 8. A. Weinstein 4 Feb 2009 – Moriond 10

LSI+61 303: 2006 -2008 2006 -2007 only 2007 -2008 Consistent with MAGIC Consistent with 2006 -2007 spectrum • Γ=2. 40± 0. 16 (stat) ± 0. 2 (sys) A. Weinstein 4 Feb 2009 – Moriond • Γ=2. 6± 0. 6 (stat) ± 0. 2 (sys) Phase-resolved (0. 5 -0. 8) 11

LSI 61+303 2008 -2009 2007 -2008 I EL PR apastron 2006 -2007 Y AR IN M 5σ 4. N o de st ng n te de io ro ct 4σ te 8. ss ce ex n io ct periastron σ). 6 (2 IM EL PR 6 3. Y AR ls ia -tr e pr IN σ A. Weinstein 4 Feb 2009 – Moriond Strong indication of orbit-to-orbit variability 12

Nov 2008 In Context Fermi data (Dubois, AAS, 2009) detects the source continuously Nov. 2008 data part of a MWL campaign: Emission peaks at periastron I EL PR Y AR IN M orbit-orbit variability(? ) Sees clear periodicity VERITAS data: 99% upper flux limit: F(E>500 Ge. V)< 1. 26 x 10 -12 cm-2 s-1 (2. 1% Crab) A. Weinstein ? 4 Feb 2009 – Moriond Apastron, 2006 -2007 13

VERITAS Sky Survey q. Partial survey of Cygnus region -1 < b < 4 and 67 < l < 82 q Completed this fall (along with a small/moderate amount of followup) At least 6 hrs acceptance-corrected exposure at each point in the survey Survey analysis ongoing (release pending observations in April) A. Weinsteinadditional 4 Feb 2009 – Moriond 14

MGROJ 1908+06 / HESS J 1908+063 EL IM IN AR Y q. Needed a test case for Sky Survey extended source search, chose MGRO J 1908+06/HESS J 1908+063 PR MGRO unidentified source Ø 80% of Crab Nebula Flux, <2. 6° diam. extension at 20 Te. V Significance Map (smoothed) Detected in HESS galactic plane survey Ø 14% Crab flux > 300 Ge. V Ø Source extension 0. 21°± 0. 07° (stat) ± 0. 05°(sys) q VERITAS Data taken under aegis of sky survey ~22 h of 4 -telescope data 4. 85σ detection ~0. 19°± 0. 04° extension position in agreement with HESS J 1908+063 A. Weinstein 4 Feb 2009 – Moriond 15

AGILE 2021+4024 q Observations (initially under moonlight) triggered by AGILE atels q 7 hour exposure q 99% upper limit at 2% Crab flux above 300 Ge. V. A. Weinstein 4 Feb 2009 – Moriond 16

Future prospects q A new guide: q new Fermi pulsars, or sources w/PWNe associations → PWN searches, searches for pulsed emission from gamma-ray loud pulsars (if cutoff is favorable), new Fermi XRBs q Ge. V-Te. V connection → disentangling nature of object, emission (e. g LSI, IC 443…) q Coordinated Ge. V-Te. V observations A. Weinstein 4 Feb 2009 – Moriond 17

Summary q VERITAS Galactic science program in first 2 years has been fruitful SNR/PWN detections: Crab, Cas. A, IC 443 Un. ID detections: MGRO J 1908+06/HESS J 1908+063 Long-term observations (+MWL) of LSI 61+303 have contained some suprises Expect: updated analyses of SNR detections (Cas A, IC 443) Expect a number of new results by summer, including the Sky Survey q Moving T 1 will improve our sensitivity to galactic sources q Fermi data and VERITAS Sky Survey results will likely modify our observing strategy for the coming year A. Weinstein 4 Feb 2009 – Moriond 18

EXTRA/ BACKUP A. Weinstein 4 Feb 2009 – Moriond 19

The Crab: A Standard Candle 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 (but mirror reflectivity now degraded) A. Weinstein 4 Feb 2009 – Moriond MAGIC ~2% Crab in 50 hours 20

Geminga q VERITAS Observations: 13. 3 hours at high elevation q Upper Limit to steady emission(>300 Ge. V): <2 x 10 -8 γ/m 2/s (~1% Crab flux) q Upper Limit to pulsed emission(>300 Ge. V): <1 x 10 -8 γ/m 2/s (~0. 5% of Crab flux) A. Weinstein 4 Feb 2009 – Moriond 21

IC 443 • Green – Radio • Red – Optical • Blue – X-rays A. Weinstein 4 Feb 2009 – Moriond 22

IC 443 q Middle-aged SNR ~ few – 10 kyr q SNR shell / molecular cloud interaction (beam dump) q PWN (southern edge): spin-down luminosity uncertain (1036 erg/s – 5 x 10 1037 erg/s) PR EL IM IN A R Y q Co-discovered (MAGIC/VERITAS) in Te. V in 2007 q Observed (wobble, 0. 5º offset) during two epochs, for 37. 1 hrs total livetime: Feb / Mar 2007 with 3 telescopes, PWN location Oct / Nov 2007 with 4 telescopes Ø Center of Feb/Mar hot spot: Ø 06 16. 9 +22 33 PWN A. Weinstein 4 Feb 2009 – Moriond q Flux ~3% Crab q 8. 2σ peak significance pre-trials 23