1 / 14

Wide Field of View surveying in Next Generation GeV/TeV Observatories

Wide Field of View surveying in Next Generation GeV/TeV Observatories. D. Kieda University of Utah. Milagro Cygnus Arm Detection. Significance is 5.5  (Crab is 5.9) Source extent is ~5 o Implied source flux is several Crab.

kairos
Download Presentation

Wide Field of View surveying in Next Generation GeV/TeV Observatories

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wide Field of View surveying in Next Generation GeV/TeV Observatories D. Kieda University of Utah UCLA Gamma Ray Workshop

  2. Milagro Cygnus Arm Detection • Significance is 5.5  (Crab is 5.9) • Source extent is ~5o • Implied source flux is several Crab R. Atkins et al, 22nd Texas Symposiumon Astrophysics, Stanford (2004) UCLA Gamma Ray Workshop

  3. Whipple Follow-up • No Strong point source evident (given # of trials) • Typical point source flux limit~300 mCrab • Quoted for E > 400 GeV , angular resolution ~ 0.05o. • Milagro source diameter >> f.o.v. of Whipple camera G. Walker, Ph.D Thesis, U of Utah (2004) UCLA Gamma Ray Workshop

  4. Source Detectability Source Size < Angular resolution = Point Sources: Crab AGN M87 constant UCLA Gamma Ray Workshop

  5. Source Detectability Source Size > Angular Resolution = Diffuse Sources: SNR Tibet-Milagro UID Molecular Cloud n.b. if Source has internal structure you will do better UCLA Gamma Ray Workshop

  6. HESS Diffuse Sources Many sources appear to have internal structure: Ability to resolve a diffuse source is a key to determining its astrophysical processes (HESS , 2005) UCLA Gamma Ray Workshop

  7. Source Resolvability Source Size > Angular Resolution Just need some factor >1 more S/N to resolve internal source structure UCLA Gamma Ray Workshop

  8. Source Resolvability Source Size < Angular resolution As F increases, tails of Gaussian become detectable->resolve source size UCLA Gamma Ray Workshop

  9. Source Detect/Resolve • Increased Milagro sensitivity • for extended source • longer exposure • Wider fov • Excellent Point Source sensitivity • of IACT does not help here • Note that this plot neglects energy • threshold benefits of IACTs X Detected Milagro only Detected (both) Whipple UCLA Gamma Ray Workshop

  10. Newer Arrays Extended Sources: Molecular clouds SNR Point Sources: AGN Pulsar Diffuse Sources: Galactic Plane Galactic Arm Next Gen is 1 km2 IACT, 5 deg f.o.v, 1 mCrab/50 hours UCLA Gamma Ray Workshop

  11. Larger Sources Imaging Source diameters > IACT f.o.v requires multiple pointing 4 pointings: 200 hours: about the most one can do per year Larger areas require reduced time/pointing, thereby reducing sensitivity Intersect at (Fx, x) UCLA Gamma Ray Workshop

  12. Larger Sources vs. Wider f.o.v IACTs H=Hawk N=Next Gen Typical UCLA Gamma Ray Workshop

  13. Summary • Source sensitivity depends on source diameter • If Cyg Arm is truly diffuse source, it is barely accessible to current IACT • Next Gen area 100 x HAWC can compensate for 10% on-time efficiency • Next Gen ( 1 km2) IACT superior for • Next Gen needs fov > 100 in order to resolve 250 diffuse sources • Next Gen better for resolving sources, point sources, looking deeper • HAWC-type better for large diffuse sources (ignoring energy threshold differences) UCLA Gamma Ray Workshop

  14. Strategy • HAWC All-sky: Monitor + large scale structure • Large IACT Next Gen looks deep, low E (followup), spectral/time evolution • Limited energy range above 10 TeV-200 TeV: probe with km2 array of small (1 m class) dedicated imagers • Study/design phase: Next year? • Pursue Modular design: • quick test/low cost • allow deploy/test subsystem at high altitude? • Site testing? • Easy final deployment, cheaper fabrication/maintenence UCLA Gamma Ray Workshop

More Related