HETE-WXM: Fenimorean GRB Localization On A Shoestring

HETE-WXM: Fenimorean GRB Localization
On A Shoestring
Carlo Graziani
Center For Astrophysical Thermonuclear Flashes
The University of Chicago
2 September 2009
Outline
HETE — The Mission
HETE Operations
Ed Fenimore, Scientist
HETE — Mission Origins
Conference: “Gamma-Ray Transients”, UCSD, 1981. Ed,
Don Lamb, Kevin Hurley, Stan Woosley are present.
Panel discussion addresses question “What, as best can be
determined at the present time, should be our priorities for
future experiments?”
“Accurate source location are also essential if gamma-ray
bursts are to cease being astrophysical curiosities and enter
the mainstream of astronomical research.” (AIP
Proceedings 77, p. 499).
HETE — Mission Origins
Conference: “High-Energy Transients In Astrophysics”,
UCSC, 1983
HETE — Mission Origins
Conference: “High-Energy Transients In Astrophysics”,
UCSC, 1983
HETE — Mission Origins
Conference: “High-Energy Transients In Astrophysics”,
UCSC, 1983
HETE — Mission Origins
Present from future HETE team: Ed, Don Lamb, Kevin
Hurley, Stan Woosley, Nobu Kawai.
Discussion on possible space missions focuses on a “High
Energy Transient Explorer” mission. A committee is
designated to write a White Paper for NASA’s edification
and entertainment.
Ed hosts follow-up meeting at LANL for White Paper
committee, October 1983.
The proposed “Explorer Class” mission has an instrument
complement including an all-sky x-ray monitor which
“...should allow accurate localization of the event from the
single spacecraft.”
HETE — Mission Origins
MOU signed with NASA in 1990.
Partnership: PI is George Ricker (MIT); Gamma-Ray
detector (FREGATE) is a French (J-L Atteia)+Berkeley
(Kevin Hurley) collaboration; X-Ray monitor (WXM) is a
Japanese (N. Kawai)+LANL (Ed) collaboration; Chicago
(Don Lamb) provides science support and WXM ground
analysis software.
Total mission cost ∼$25-30M, including launch; ∼$15M to
NASA.
Launch failure November 1996.
Successful Launch of HETE-II in October 2000.
HETE Spacecraft
HETE Instrument Complement
HETE Ground Stations
HETE Wide-Field X-Ray Monitor (WXM)
Main GRB localization instrument aboard HETE.
HETE Wide-Field X-Ray Monitor (WXM)
Hardware collaboration between RIKEN (the PSPC) and
LANL (the coded-aperture mask).
Camera design: two 1-D coded-aperture arrays —
localization, not imaging.
HETE Wide-Field X-Ray Monitor (WXM)
The WXM Team:
RIKEN (Nobu Kawai): PSPC hardware, flight software;
LANL (Ed): Mask, flight trigger + location software,
spectral response matrices;
Chicago (Don Lamb): Ground location software.
HETE VHF Console — Normal State
HETE VHF Console — Burst Alert
All Quiet On HCHAT
GRB010326: Exciting HCHAT Action
GRB010326: Working The Problem On HCHAT
GRB010326b!
Wrap-up Of GRB010326b on HCHAT
Some Reflections On HETE Operations
Future historians of science please note: The HCHAT logs
mean that HETE is probably one of the most minutely
recorded scientific missions in history. Almost all
discussions of operations, and many science discussions left
imprints in those logs.
Being small and poor also meant being free (of NASA).
More Reflections On HETE Operations
Ed taught us paranoia. He drilled this into us: Do
everything in twos (or threes, or fours...).
Two separate and very different flight trigger systems
(LANL and CESR/France);
Three separate and very different WXM ground location
pipelines (Chicago, RIKEN, LANL) (and that’s not
counting the MIT SXC pipeline);
Two separate and very different ground trigger pipelines
(Chicago, MIT/Berkeley);
Two separate and somewhat different spectral analysis
pipelines (MIT and Taka “The Pipeline” Sakamoto in
Japan).
Two separate and very different WXM response matrix
generation methods (LANL and RIKEN).
Why Does Ed Always Think He Might Be Wrong
(Even When He’s Right)?
A meditation on Ed’s unyielding commitment to scientific
truth.