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1 HETE-II Catalogue HETE-II Catalogue Filip Münz, Elisabetta Maiorano and Graziella Pizzichini and Graziella Pizzichini for HETE team Burst statistics in
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French Gamma-ray Telescope (FREGATE): 5-400 keV; ~π FOV no localization gamma-ray detector French Gamma-ray Telescope (FREGATE): 5-400 keV; ~π FOV no localization Wide-Field X-ray Monitor (WXM): 2-25 keV; ~5’-10’ localizations Soft X-ray Cameras (SXC): 2-10 keV; ~40” localizations small eff. surface / sensitivity position sensitive instruments Wide-Field X-ray Monitor (WXM): 2-25 keV; ~5’-10’ localizations Soft X-ray Cameras (SXC): 2-10 keV; ~40” localizations small eff. surface / sensitivity direct alert transmission through simple VHF stations along the equatorial trajectory High Energy Transient Experiment – II very small scale mission mass: 123 kg size: 89 x 66 cm (launch size) Pisa, May 2009
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HETE-II GRB Catalogue Detector response FREGATE large FoV implies high background (with Earth occultation of sources due to fixed pointing ) WXM extension to lower energies with complicated response matrix (1-D coded masks) 1292 GCN alerts 173 bursts 143 localized (110 within 1 hour) Pisa, May 2009
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GRB – SN connection (030329A) HETE Highlights HETE X-ray (Chandra) optical first short burst OT (050709) Pisa, May 2009
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Catalog content 284 bursts (some cancelled later) results of analysis of different groups more concerning position reconstruction Pisa, May 2009
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Checking the catalogue correlation of different variables (160 entries) looking for outliers Pisa, May 2009
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GRB entry All links on one page to general catalogue to GCN notices to literature custom notes Pisa, May 2009
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Catalogue structure Database (mySQL) with object interface (and web replication ) Numerical Python, Django, JQuery light-curve profiles in ASCII/FITS procedures to load and subtract background Burst (trigger info) Alert (time of distribution) Spectral fits Band (X/gamma) Peak (times,fluence) Literature refer. Afterglow measures GCN notices Position info Pisa, May 2009
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Afterglows Many bursts have good coverage of optical afterglows Combining with analysis of prompt lightcurves Pisa, May 2009
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Success of followups The anti-solar HETE pointing was friendly for ground observers and the frequency of GRB alerts was lower at the time of HETE detections. (until 2007) Pisa, May 2009
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HETE-2 Observations of GRB021211 Crew et al. (2003) first HETE localization after 33 sec., OT reported by Fox & Price (GCN 1731) after 53’17”. Pisa, May 2009
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GRB021211: Afterglow Light Curve Relative to Those of Other GRBs The optical afterglow of some bursts is much fainter (~ 3 mag) than those previously observed: without HETE’s prompt localization, this GRB would very likely have been listed as “dark”, instead of “dim”. But it proves that at t < 10 min even “dim” afterglows may be bright (m ~ 13). This was very promising for Swift. Pisa, May 2009
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Amati relation revisited Amati relation extended to X-Ray Rich GRBs and to X-Ray Flashes Pisa, May 2009 Amati relation extended to X-Ray Rich GRBs and to X-Ray Flashes
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Pisa, May 2009 Lightcurve analysis trying to extract information besides T90/fluence developing methods for identification of peaks need for sampling independent parameters
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Lightcurve parade Pisa, May 2009
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Work in progress make catalogue ready for public checking outliers linking the literature polishing the interface prompt emission studies more detailed statistics comparison with other datasets (BATSE, Swift) need for robust peak-analysis technique better pseudo-redshift indicator Pisa, May 2009
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Alert distribution IASF-BO people E. Morelli F. Gianotti P. Ferrero F. Munz G. Pizzichini equatorial orbit @ 625 km
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HETE catalog completing, verifying, mining …
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Correlations Extension of Amati relation Classification of XRR / XRF / GRBs
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HETE classification
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Prompt emission FREGATE analysis in 4 spectral bands 7-40 keV 7-80 keV 30-400 keV >400 keV time sampling at cca 0.1 s conversion to physical units using off-axis angle and spectral shape spectrum fitted in 69 cases
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Lightcurve analysis Sometimes the main structure comes with considerable delay (no background information after the burst)
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Peak separation dissecting those that fall bellow the background fluctuation (on both sides) no assumptions on the peak shape can check the residuals (succesful background subtraction) band1234567 7-408435231341 7-8074512213 30-40081332061 >400234211 2-51221 5-1085 10-1893 18-251041
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Peak parameters
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Peak width evolution
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Hardness evolution 26 bursts 14 bursts with spectra (11 with pseudo-redsift)
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Peak lags 30 bursts 77 peaks
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Peak lags correlation 0.39 spearman rank 0.37
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Lightcurve analysis in some cases the baseline level is not evident at all! aim is to verify the catalogued values and deepen the understanding of X-ray rich events
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