AGILE AGN Working Group S.Mereghetti - on behalf of the AGILE Team

Transcription

1 AGILE Scientific Program and S. Mereghetti on behalf of the AGILE team Data Rights

2 AGILE Science Management Plan High level document issued in February 2004 Defines: Scientific Management of the mission Guidelines for Pointing Program High level project organization and share of responsibilities for ground segment Scientific Programs and Data Rights Policies

3 Basics of AGILE Ground Segment

4 Basics of AGILE data flow TM data received at ASDC on a contact by contact basis (= every 95 minutes) Processed by automatic pipelines developed at ASDC by combining software packages developed by AGILE Team Quick Look Analysis at ASDC and AGILE Team labs. (automatic and interactive) High level GRID data products (event files, etc..) distributed to users Results of Super-AGILE analysis made by AT+ASDC available through WWW

5 Basics of GRID data processing

6 AGILE Scientific Program Pointing Plan defined a priori to optimize sky coverage, multi wavelength programs, etc. Data allocation instead of Time allocation SuperAGILE (20-40 kev) publicly available RESULTS (no SuperAGILE data distributed) GRID data (30 MeV 50 GeV) AGILE Team Projects Guest Observers Program AO document in preparation

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8 Meeting 15/2/2006

9 High energy charged particles constitute the vast majority of background events ~ 0.1 particles /cmq/s/sr at E>10 MeV 10 khz in GRID

10 Background S.Mereghetti Rejection: - behalf of the AGILE Team Albedo photons

11 Earth Albedo Photons Albedo photons are high energy photons, physically indistinguishable from celestial photons A simplified track reconstruction is done on board to cut albedo photons

12 Meeting 15/2/2006 Kalman filter attempts to find two tracks consistent with pair production from a high energy photons (failing that, one track only) µ but: wonly projection information wmultiple Scattering wnoise hits

13 Complete simulation SW includes: -Geant Montecarlo -Electrical noise simul. -On board data handling Used for HW design, SW development and testing, derivation of instrument response, etc.. Calibration data: - characterize baseline for ground-based analysis -necessary for response matrix calculation - small sample calibrates extensive MC and DH Simulations

14 DHSIM has been used to optimize on board background rejection

15 Preprocessing = direct translation from raw telemetry into FITS (LV1) Correction checks and updates FITS files (COR). Corrected event files contain in tabular form physical GRID events that have passed the onboard filters. At ~10 Hz, ~100 times more background events (particles + albedo photons) than celestial photon events

16 Kalman Filter Few operations required (find, fit) Takes into account the MS Produces : photon direction quality factor

17 Basics of GRID Scientific Analysis WCS: ARC projection Rectangular coords unsuitable if celestial pole in FOV Counts maps Inputs: photon event files Exposure maps Inputs: instrument log files, effective area files Diffuse emission maps Diffuse model, Point spread dispersion files

18 Event Files simulated data

19 Counts maps The value in each bin (default 0.25x0.25 ) is the number of photons detected within that bin in the given time within the given energy range Automatically finds relevant event files by consulting index file

20 Counts map simulated data, multiple pointings

21 Counts map S.Mereghetti True - on behalf photons!! of the AGILE Team (calibration data, on axis source)

22 nts maps Standard FITS headers with WCS keywords mean one can use FTOOLS such as fv, ds9, saoimage for quicklook display ximage for quicklook source detection

23 ximage Multiple pointings

24 Exposure maps The exposure map gives for each direction the product of the sky pixel solid angle and the instrument effective area integrated over the live time as a function of energy Exposure varies over time due to instrument pointing, occultation, background fluctuations, etc. Automatic lookup of log files through log file index Projection information identical to counts maps

25 Exposure maps

26 Diffuse Gamma-ray Emission Produced by high energy cosmic rays interacting with interstellar matter and radiation Cosmic rays from theoretical SNR distribution + diffusion Matter density HI from 21 cm radio H 2 from CO line HII from radio pulsar dispersion ISRF from CMB, COBE, MAP, theoretical models

27 2-D + rotation curve = 3-D Velocity km/s R (kpc)

28 Meeting 15/2/2006 Diffuse Emission - HI Leiden-Dwingeloo and Leiden-Argentine-Bonn 21cm radio surveys

29 3-D HI map

30 Diffuse emission -H 2 Harvard-Columbia CO survey (Dame et al.)

31 Diffuse Emission: ISRF

32 AGILE Diffuse BKG Model II Galactic Quadrant

33 e Emission Map Diffuse model is convolved with point spread function summed over energy weighted by spectrum binned according to projection used by counts and exposure maps

34 Point Source S.Mereghetti Detection - behalf of the AGILE Team & Flux Measurement Maximum Likelihood Cumulative probability of counts map given model and Poisson statistics Model includes Diffuse (galactic) emission * exposure Isotropic ( extragalactic ) emission exposure Inactive sources and particle background (fixed) Active source Each analysis task iterations over a simpler task multiple srcs source loc TS, flux ln L

35 Point source location Comparison with EGRET

36 Simulation of multiple sources detection and analysis

37 Energy Reconstruction Information from different methods/components Mini-calorimeter Track length Multiple scattering Goodness of fit vs. opening angle

38 Energy Meeting 15/2/2006 reconstruction from multiple scattering analysis Based on Moliere formula and taking into account bremsstrahlung energy losses Energy response matrix (true vs. derived energy in MeV)

39 Example of spectral results F(>100 MeV)= ph/cmq/s = 0.07 Crab