F.Fuschino, F.Longo et al AGILE view on TGF F. Fuschino, F. Longo, M. Marisaldi, C. Labanti, M. Galli, G. Barbiellini on behalf of the AGILE team

F.Fuschino, F.Longo et al Outline The AGILE satellite –Brief introduction The AGILE Mini Calorimeter (MCAL) –Burst Trigger Mode –Gamma-ray Burst detection Terrestrial Gamma Flashes –Detection by AGILE-MCAL The AGILE first photon – May 10, 2007

F.Fuschino, F.Longo et al AGILE

AGILE AGILE

F.Fuschino, F.Longo et al Detection Technique

F.Fuschino, F.Longo et al AGILE instrument

F.Fuschino, F.Longo et al AGILE: inside the cube… ANTICOINCIDENCE INAF-IASF-Mi (F.Perotti) HARD X-RAY IMAGER (SUPER-AGILE) INAF-IASF-Rm (E.Costa, M. Feroci) GAMMA-RAY IMAGER SILICON TRACKER INFN-Trieste (G.Barbiellini, M. Prest) (MINI) CALORIMETER INAF-IASF-Bo, Thales- Alenia Space (LABEN) (G. Di Cocco, C. Labanti)

F.Fuschino, F.Longo et al Sriharikota launch base (India) PSLV-C8 launch, April 23, 2007 The AGILE instrument

F.Fuschino, F.Longo et al Vela, Geminga, Crab PSR timing Monitoring of many Galactic hard X-ray sources Blazar detections –3C 279 –3C 273 –3C (repeated gamma-ray flares) –PKS – –W Comae, Mkn 421 Several GRBs detected by SuperAGILE and MCAL (MCAL detects ~ 1/week) Discovery of transient gamma-ray sources in the Galactic plane. AGILE results

F.Fuschino, F.Longo et al C Cygnus region AGILE gamma-ray sky: 22 Nov. 2007

F.Fuschino, F.Longo et al AGILE view of the sky

F.Fuschino, F.Longo et al The AGILE MCAL

F.Fuschino, F.Longo et al The Mini-Calorimeter (MCAL)‏ 30 CsI(Tl) bars with Photodiode readout 1400 cm 2 geometrical area ~360 cm 2 effective 1 MeV 330 keV – 100 MeV energy range 14% energy resolution 1.3 MeV 2 ms timing accuracy in photon-by-photon mode Clever, fully-programmable GRB trigger logic 40 cm

F.Fuschino, F.Longo et al On Board AGILE Trigger BURST -GRB SEARCH -SA IMAGE DECONVOLUTION TELEMETRYTELEMETRY The AGILE instrument

F.Fuschino, F.Longo et al MCAL Trigger Logic MCAL Burst Search logic: 1ms, 16ms, 64ms, 256ms, 1.024s, 8.192s Search Integration Time (SIT) 4 spatial zones and 3 energy ranges ( 1400 keV)‏ static and dinamic thresholds for start and stop generation dedicated look-up tables to accept/reject triggers very flexible: more than 2000 parameters for full configuration Configured in November 2007, steadily active since February 2008

F.Fuschino, F.Longo et al MCAL GRB search testing (Tortona, June 2006) The AGILE instrument

F.Fuschino, F.Longo et al MCAL and its partners in space 49 cosmic GRBs detected by AGILE-MCAL between 22 nd June ' th June. '08. Most of them confirmed by other InterPlanetary Network (IPN) spacecrafts Detectors with spectral capabilities in the MeV range Detector with photon-by-photon microsecond timing accuracy in the MeV range Detector with superposition > 80% with the MCAL sample and good spectral capabilities: cross- calibration activity ongoing A warm welcome to GLAST-GBM!

F.Fuschino, F.Longo et al Latest news: GRB s long, bright GRB, multipeaked, out of FOV

F.Fuschino, F.Longo et al Latest news: GRB ms short/hard, very bright

F.Fuschino, F.Longo et al Terrestrial Gamma Flashes by AGILE

F.Fuschino, F.Longo et al Terrestrial Gamma-ray Flashes (TGF)‏ Gamma-ray flashes with incoming direction compatible with the Earth surface. Few millisecond typical duration; hard spectrum (detected up to 20 MeV) ‏ Discovered by BATSE (1994) and confirmed by RHESSI (2006) ‏ Possibly associated to lightning during thunderstorms by means of correlation with VLF spheric waves detection on ground Serendipitous detection of candidate TGF by MCAL after the onset of the onboard trigger logic Undetectable without small “search integration times” (<=64 ms) and photon-by-photon data download About 20 candidates in 5 months operation

F.Fuschino, F.Longo et al MCAL candidate TGF 10 ms trigger date and time temporal bin: 100  s! time scale: < 5 ms

F.Fuschino, F.Longo et al TGF energy/position distribution AGILE position at trigger time AGILE pointing at trigger time FOV Candidate TGF on :03: 42 UT Light curves in 2 energy bands Events distribution in 2 energy bands The position distribution pattern is compatible with incoming direction from the Earth surface Earth

F.Fuschino, F.Longo et al TGF energy/position distribution AGILE position at trigger time AGILE pointing at trigger time Earth Candidate TGF on 25/3/08 15:00:02 Light curves in 3 energy bands Events distribution in 3 energy bands The position distribution pattern is compatible with incoming direction from the Earth surface

F.Fuschino, F.Longo et al Geographycal distribution

F.Fuschino, F.Longo et al Energetics Are the observed MCAL events compatible with RHESSI spectra? Smith et al Considering RHESSI and MCAL effective area ~12 counts/ms are expected in MCAL in the 500 – 700 keV band ~16 counts/ms are found: quite good agreement, refinement are expected with better calibration possibly selection effect toward bright events due to the trigger time window (64ms): expected improvements with <=16ms time windows

F.Fuschino, F.Longo et al Conclusions AGILE-MCAL is the 3 rd instrument (after BATSE and RHESSI) that observed TGF from space. Serendipity: from astrophysics to geophysics! Observation of such fast events is only possible thanks to the clever trigger logic (~ms time scale) and photon-by- photon data download with ms time resolution. The energetics of observed events is compatible with that reported by RHESSI. Definitive proof needed: search for spheric waves correlation Calibration activity ongoing: better spectral characterization Last week: enabling <16 ms time window: new discovery space opening! HW trigger 1, 16 ms  s (<1 ms)

F.Fuschino, F.Longo et al The end thank you !

F.Fuschino, F.Longo et al BackUp Slides

F.Fuschino, F.Longo et al BATSE TGF ~ 70 TGF detected on 9 life-Years typically 100 counts/TGF On-Board Trigger Logic performances: Shorter timescale => 64ms Significance => 40 sigma above the background on two separate detector Fishman et al Ostgaard et al. 08

F.Fuschino, F.Longo et al RHESSI TGF TGF Distribution with lighting frequency per km 2 per Year Continuous time-tagged event list NO ON-BOARD TRIGGER LOGIC 10– 20 TGF per month Typically counts/TGF Distribution of average energy for the RHESSI TGFs (histogram) along with a simulated brehmstrahlung spectra. Smith et al. 2005