April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

HETE-2

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

OverviewThe 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• Field of View: 0.91 sr• Focal Plane scale: 33" per CCD pixel• Burst Sensitivity: (4 sigma) 0.47 cts cm-2 s-1• Steady source Sensitivity: (4 sigma) ~700 mCrab t -1/2• Localization Precision: 80" (systematic + statistical) 90% conf limits

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

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 z=0.16. “Solved mystery of short-hard bursts”

See Villasenor et al., 2005, Nature 437, 855

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

Archive StatusHEASARC 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)

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

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)

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

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

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

Future status

• HETE-2 not involved in current senior review round

• NASA 07 budget request

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

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

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

Lessons Learned• Primary GRB science goals achieved/exceeded in an

exceptionally low-cost mission (<$600K 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

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

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 isn’t free either)

April 12 - 13, 2006HEASARC Users Group

Mike Corcoran

How the HEASARC can HelpThe 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”