HETEII Catalogue

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HETE-II Catalogue
Burst statistics in

• Filip Münz and Graziella Pizzichini for
  HETE team

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• Gamma-ray bursts in
• HETE-II Catalogue

• Filip Münz and
• Graziella Pizzichini
• for HETE team

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High Energy Transient Experiment II

• gamma-ray detectorFrench Gamma-ray Telescope
  (FREGATE) 5-400 keV p FOVno localization
• position sensitive instrumentsWide-Field X-ray
  Monitor (WXM) 2-25 keV 5-10
  localizationsSoft X-ray Cameras (SXC)
  2-10 keV 40 localizationssmall eff.
  surface / sensitivity
• direct alert transmission through simple VHF
  stations along the equatorial trajectory

very small scale mission mass 123 kg size 89
x 66 cm (launch size)
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Alert distribution
IASF-BO people E. Morelli F. Gianotti P.
Ferrero F. Munz G. Pizzichini
equatorial orbit _at_ 625 km
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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)

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HETE detections

• 1292 GCN alerts
• 173 bursts
• 143 localized
• (110 within 1 hour)

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HETE Highlights
optical

• first short burst OT (050709)

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HETE catalog

• completing, verifying, mining

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Catalog content

• 284 bursts (some demented later)
• results of analysis of different groups
• more concerning position reconstruction

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Checking the catalogue

• correlation of different variables (160 entries)
• looking for outliers

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GRB entry

• All links on one page
• to general catalogue
• to GCN notices
• to literature
• custom notes

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Catalogue structure
Spectral fits

• 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)
Literature refer.
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Correlations

• Extension of Amati relation
• Classification of XRR / XRF / GRBs

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HETE classification
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Afterglows

• Many bursts have good coverage of optical
  afterglows
• Combining with analysis of prompt lightcurves

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Success of followups

• highlights
• GRB 030329B (690/488)
• GRB 021004 (178/123)
• GRB 020813 (77/67)

(until 2007)

• result of ground-obs. friendly (anti-solar) HETE
  pointing
• too many bursts in SWIFT era

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Amati relation revisited
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Prompt emission

• FREGATE analysis in 4 spectral bands
• 7-40 keV
• 7-80 keV
• 30-400 keV
• gt400 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

• trying to extract information besides T90/fluence
• developing methods for identification of peaks
• need for sampling independent parameters

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Lightcurve parade
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Lightcurve analysis

• Sometimes the main structurecomes with
  considerable delay(no backgroundinformation
  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)

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Peak parameters
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Peak parameters
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Peak width evolution
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Hardness evolution
14 bursts with spectra (11 with pseudo-redsift)
26 bursts
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Hardness evolution
14 bursts with spectra (11 with pseudo-redsift)
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(not so) special cases
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Peak lags
30 bursts77 peaks
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Peak lags
correlation 0.39spearman rank 0.37
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Lightcurve analysis

• in some cases the baseline level isnot evident
  at all!
• aim is to verify the catalogued values and deepen
  the understanding of X-ray rich events

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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