April 12 - 13, 2006

1
HETE-2
2
Overview

• The High Energy Transient Explorer (HETE-2) is a
  University-Class (small) scientific satellite
  designed to detect and localize gamma-ray bursts.
  The coordinates of GRBs detected by HETE are
  distributed to interested ground-based observers
  within seconds of burst detection, thereby
  allowing detailed observations of the initial
  phases of GRBs. Follow-on to HETE (lost just
  after launch, Nov 1996). Hete-2 Launched Oct 9,
  2000
• Instruments
• French Gamma Telescope (FREGATE)
• Instrument type NaI(TI) cleaved
• Energy Range 6 to 400 keV
• Timing Resolution 10 microseconds
• Effective Area 120 cm2
• Sensitivity (10 sigma) 3x10-8 erg cm-2s-1, over
  8 keV-1 MeV
• Field of View 3 steradians
• Wide Field X-ray Monitor (WXM Riken/LANL)
• Instrument type Coded Mask with Position
  Sensitive Proportional Counter
• Energy Range 2 to 25 keV
• Timing Resolution 1 ms
• Sensitivity (10 sigma) 8x10 -9 erg cm -2s -1
  over the 2-10 keV range
• Field of View 1.6 steradians (FWZM)
• Angular resolution -11 arcmin (normal
  incidence, 8 keV)
• Soft X-ray Camera (SXC MIT/MKI)
• Energy Range 500 eV to 14 keV
• Timing Resolution 1.2 s

3
Mission Status

• All instruments (Fregate, WXM SXC) currently
  operating nominally problems early on
• Since last HUG meeting (2004)
• 27 refereed publications in ADS
• 34 bursts (24 Fregate triggers, 4 WXM triggers, 6
  Ground Analysis)
• GRB050709 first optical afterglow of a
  short-hard burst associated with a late-type
  galaxy at z0.16. Solved mystery of short-hard
  bursts

See Villasenor et al., 2005, Nature 437, 855
4
Archive Status

• HEASARC is the primary archive for HETE-2
• 260 GB of data in IPP format - optimized for
  efficient burst analysis (not long-term archive)
• Fregate 3-band lightcurves for all available GRBs
• XSPEC-compatible spectra and response matrices
  for Fregate bursts
• Hete2help 3 contacts since 2000
• Data transfer to community 700 MB (mostly in
  2005)

5
HETE2 Metadata

• Browse tables
• hete2gcn searchable list of all HETE2 gcn
  notices with links to data
• hete2grb searchable list of all HETE2 bursts
  with links to data and to MIT burst pages
• hete2tl searchable HETE2 timeline with data
  links
• xtime hete2 pointing timeline (like hete2tl)

6
Website Software

• HEASARC Hete2 website contains general
  information about Hete2, links to burst web pages
• /FTP/hete2/ops contains downloadable software
  (solaris binaries and perl/c-shell scripts) Not
  user friendly

7
Future status

• HETE-2 not involved in current senior review
  round
• NASA 07 budget request

8
Future Plans

• MIT funding runs out in Jun 06 operations
  authorized until Sep 06
• HEASARC will
• maintain archive of all IPP data
• maintain mirror of MIT HETE2 website
• transfer all processing/analysis software from
  MIT to HEASARC for download
• maintain calibration data
• Continue to investigate conversion of data into
  standard format on a best-effort basis

9
Lessons Learned

• Primary GRB science goals achieved/exceeded in an
  exceptionally low-cost mission (lt600K yr-1 for
  DA)
• Triage decision Insufficient funds were
  provided to PI team to undertake secondary
  (non-GRB) science analyses
• Small missions often have to decide between main
  mission science vs. long-term archiving Main
  mission science (usually) wins

10
Lessons Learned (cont)

• Producing data in standard formats readable by
  software outside of mission-developed tools is
  essential for broader use.
• Projects should incorporate long-term archive
  plans in their PDMP to maximize long-term
  usefulness
• Adherence to data standards (FITS) from outset is
  important for long-term archiving data
  ease-of-use, but there are (some) mission costs.
• Convert telemetry to FITS!
• Adherence to software standards is important too
  (but this isnt free either)

11
How the HEASARC can Help

• The HEASARC helps minimize effort for small
  projects to standardize data
• enabling easy creation/verification of FITS files
  (cfitsio)
• providing well-defined, easy to understand, easy
  to find data standards (OGIP Standards)
• Expandable software standards (HEASoft)
• Calibration infrastructure (CALDB)
• Even small missions can find data attractiveness