GRB Spectrum simulating a transient source

1. GRB Spectrumsimulating a transient source Status Report Nicola Omodei Johann Cohen-Tanugi 1 Nicola Omodei - Pisa - 18/02/02

2. The activities… • FluxSvc • General Design • GRBSpectrum • GRBTest • Some results (presented as picture gallery) • Scientific Group Activities 2 Nicola Omodei - Pisa - 18/02/02

3. Flux Svc • Selection of different particle for the simulation • Different Sources • Primary and secondary Galactic Cosmic Rays: protons and electrons • Albedo gammas • Gammas for testing resolution • Galactic gamma point sources • Galactic diffuse sources • Transient sources-> GRB Spectrum • The satellite is illuminated in the correct way • Given the position of the source FluxSvc computes the incident photon’s angle depending on the orbit of GLAST. 3 Nicola Omodei - Pisa - 18/02/02

4. GRB simulation • We’ve started from a plausible astrophysical source model (Fireball Model) that describes the temporal behavior of a typical Gamma Ray Burst • Rapid variable signal (ms) • Non thermal emission (Synchrotron & Inverse Compton Scattering) • XML description not yet available • Dictionary of spectra implemented for look up • Many parameters -> might be clumsy • Chance to have a ‘real’ simulator (also for the sources) Written Entirely in C++ 4 Nicola Omodei - Pisa - 18/02/02

5. How does the model work ? 5 Nicola Omodei - Pisa - 18/02/02

6. FluxSvc What does GRBSim do ? 6 Nicola Omodei - Pisa - 18/02/02

7. Light Curves Short Bursts & Long Bursts Complex Shapes The harder peaks are shorter and peak before 7 Nicola Omodei - Pisa - 18/02/02

8. Contour Plot <- Synchrotron Time (sec) Log(energy) Time (sec) Synchrotron & IC -> Log(energy) 8 Nicola Omodei - Pisa - 18/02/02

9. Spectrum Different Emission processes are included. The Shape of the spectrum will be a key study to understand the nature of this phenomenon. 9 Nicola Omodei - Pisa - 18/02/02

10. Waves, Mountains ? No GRBs !! 10 Nicola Omodei - Pisa - 18/02/02

11. “Root Plot” It plots a certain number of events Extracted from a Flux of the source library. An already existing test executable is capable to use GRB 11 Nicola Omodei - Pisa - 18/02/02

12. “To do list” about the SW… • Clean Up the code (as always)… • Include different HE emission processes (  annihilation) • Study the surrounding Media • Precursor plerionic activity in the SN model of GRB: “External Compton” (Inoue, Guetta & Pacini) • Documentation (Doxigenation !!!) • Extensive use of ROOT !! • Graphical User Interface ? • Validation Procedure (also with ROOT) • Spectral & Temporal analysis: • The spike duration depends on the energy band of the light curve (harder spikes are shorter) • Variation of the spectral indexes in the time • Collect data of the MC response: • Database ? • Starting the analysis… 12 Nicola Omodei - Pisa - 18/02/02

13. EC: A nice signature… We compute the Photon Distribution @ 95 min after the burst (Inoue, Guetta & Pacini) Remember the 18 GeV Photon Detected by EGRET !! For the SSC Model… …& for the EC Model 13 Nicola Omodei - Pisa - 18/02/02

14. …Scientific Working Groups • Group V (GRB & Solar Flares) • Set up a web page to organize the activity of the Group, collect ideas, graphs, data, give visibility to the activity of the Group… organize the work! • Cooperation with other W.G. • The GRB Simulator is a good example for describing a transient source and use it in the Gaudi framework. The basic structure could be extended to other astrophysical sources: AGN simulator, high energy emission from microquasars (Arcetri). • Preparation to the Collaboration Meeting • Scientific Analysis Tools 14 Nicola Omodei - Pisa - 18/02/02