1 HETE-II Catalogue HETE-II Catalogue Filip Münz, Elisabetta Maiorano and Graziella Pizzichini and Graziella Pizzichini for HETE team Burst statistics in

 French Gamma-ray Telescope (FREGATE): keV; ~π FOV no localization  gamma-ray detector French Gamma-ray Telescope (FREGATE): 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

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

GRB – SN connection (030329A) HETE Highlights HETE X-ray (Chandra) optical first short burst OT (050709) Pisa, May 2009

Catalog content 284 bursts (some cancelled later) results of analysis of different groups more concerning position reconstruction Pisa, May 2009

Checking the catalogue   correlation of different variables (160 entries)   looking for outliers Pisa, May 2009

GRB entry   All links on one page   to general catalogue   to GCN notices   to literature   custom notes Pisa, May 2009

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

Afterglows Many bursts have good coverage of optical afterglows Combining with analysis of prompt lightcurves Pisa, May 2009

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

HETE-2 Observations of GRB Crew et al. (2003) first HETE localization after 33 sec., OT reported by Fox & Price (GCN 1731) after 53’17”. Pisa, May 2009

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

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

Pisa, May 2009 Lightcurve analysis trying to extract information besides T90/fluence developing methods for identification of peaks   need for sampling independent parameters

Lightcurve parade Pisa, May 2009

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

Alert distribution IASF-BO people E. Morelli F. Gianotti P. Ferrero F. Munz G. Pizzichini equatorial 625 km

HETE catalog completing, verifying, mining …

Correlations   Extension of Amati relation   Classification of XRR / XRF / GRBs

HETE classification

Prompt emission   FREGATE analysis in 4 spectral bands   7-40 keV   7-80 keV   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

Lightcurve analysis Sometimes the main structure comes with considerable delay (no background information after the burst)

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) band >

Peak parameters

Peak width evolution

Hardness evolution 26 bursts 14 bursts with spectra (11 with pseudo-redsift)

Peak lags 30 bursts 77 peaks

Peak lags correlation 0.39 spearman rank 0.37

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