HETE-2 (High Energy Transient Explorer) a small satellite for studying the cosmic gamma-ray bursts and beyond …. Atsumasa Yoshida (RIKEN)

HETE history  1983— recommended in Santa Cruz meeting  Feb 1991— official start of HETE  US - Japan - France collaboration  multiwavelength study of GRB in UV, X-ray and gamma-ray  real-time localization and rapid notification  Nov 1996— HETE-1 launch:  lost in failure of 3rd stage separation  Feb 1997— Discovery of GRB afterglow  HETE concept proven, (but by different mission)  Jul 1997— HETE-2 started  UV camera replaced by Soft X-ray Camera in HETE-2

HETE-1 mounted on the Pegasus rocket. The small red object immediately to the left of the solar panel is a set of pyrotechnic bolt cutters, which releases the satellite from the third stage. The second and third stages of the rocket can be seen. HETE-1

HETE-1 inside the DPAF (Dual Payload Attachment Fitting) can. This structure protects HETE-1 while SAC- B is deployed. 3rd stage + HETE + SAC-B attached. The third stage is the short, black unit behind the DPAF can (along with the instrumentation ring and RCS systems ring), attached to the white second stage. This assembly is still circling the earth as one unit, after failure of the 3rd stage pyrotechnics to release both satellites.

HETE-1 Launch in November and Lost

HETE-2 Instruments

The HETE Mission  Prime objective: multiwavelength study of gamma ray bursts (GRBs) with soft/medium X-ray, and gamma ray instruments  Unique feature: capability to localize bursts with several arcsecond accuracy, in near real-time aboard the spacecraft  GRB positions transmitted to the global network of primary and secondary ground stations, enabling sensitive follow-up studies

Primary Science Goals: GRBs  provide accurate postions (±10 arcsec to ±10 arcmin) for ~30 bursts in real time each year.  factor of ~4 more sensitive than the BATSE SDs for low energy spectral features and will provide ~25 GRBs per year on which high-quality spectral studies can be performed.  The 2-25 keV and keV sensitivities of the X-ray and gamma ray instruments: effective for studying cyclotron lines and spectra of GRBs at low energies.  ~7.5 times more sensitive than BATSE to bursts from Soft Gamma Ray repeaters: event rate ~ 55 times higher than BATSE.

Secondary Science Goals  detect as many as X-ray bursts per year.  monitor the evolution of X-ray bursts and X-ray transients in the FOV of the X-ray detector.  discover and study X-ray pulsars for ~2 month intervals.  discover and study black hole transients.

Spacecraft Specification  Mass: 126 kg.  Envelope: Fits within cylinder 89cm x 66 cm dia.  Desired orbit: 600 km circular, 0 degree inclination  Operating life: 6 months, nothing to preclude 2+ years  Attitude: Sun pointing. Momentum bias. Attitude controlled to +/- 2 degrees  Data processing: Multi-processor, 80 VAX MIPS  Data Buffering: 96 MBytes of EDAC mass memory  Downlink: 250 kbits/sec data rate with overall bit error rate <2e-8 from data storage to ground archive.  Uplink: kbits/sec data rate, overall bit error rate < 1e-8  Radio Frequencies:S-band uplink (2.092 GHz) and downlink (2.272 GHz) for primary groundstation(s),  VHF downlink only ( MHz) for secondary stations.

FREnch GAmma-ray TElescope (FREGATE)  Built byCESR (France)  Instrument typeNaI(TI);cleaved  Energy Range6 keV to > 1 MeV  Timing Resolution4 ms  Spectral 6 keV 662 keV  Effective Area120 cm 2  Sensitivity (10  )3x10 –8 erg cm –2 s –1 over 8 keV—1 MeV  Field of View~2  sr

Wide-field X-ray Monitor (WXM)  Built byRIKEN and Los Alamos National Laboratory  Instrument typeCoded Mask with Position Sensitive Proportional Counter  Energy Range2 to 25 keV  Timing Resolution1 ms  Spectral 6 keV  Detector Quantum 5 keV  Effective Area~200 cm 2 for each of two units  Sensitivity (10  )~8x10 –9 erg cm –2 s –1 over the 2-10 keV range  Field of View ~2 sr (total for 4 units)  Angular resolution (1  )±6 arcmin

WXM  Two-layered multi-wire proportional counter  Be window  10  m  carbon wire  Gas mixture: Xe (97%) +CO 2 (3%)  Gas pressure 1.4atm

GRB localization with 1-D position sensitive detectors

Soft X-ray Camera (SXC)  Built byMIT CSR  Instrument type4 CCD20 Detectors, 2 optical CCD22  Camera dimensions10cmx10cmx17.5cm  Energy Range500 eV to 14 keV  Timing Resolution~1 s  Spectral Resolution eV, keV  Detector Quantum 5 keV, >20% ( keV)  Effective Area6.1x6.1 cm 2 (each of 2 units)  Burst Sensitivity (4  )0.47 cts cm –2 s –1  Steady source Sensitivity (4  )~700 mCrab x t –1/2  Field of View0.91 sr  Focal Plane scale33" per CCD pixel  Loaclization PrecisionFaint Burst, 5  - 15", Bright burst, 22 , 3" (1 Crab; 10s)

HETE2 Operation Network

Secondary Ground Station Network Kwajalein * E 8.7 N 2 Christmas Island W 1.9 N 3 Hiva Oa (French Polynesia) W 9.8 S 4 Galapagos Island (Ecuador) 91.1 W 0.7 S 5 Cayenne (French Guiana) * 51.9 W 4.9 N 6 Natal (Brazil) 35.1 W 5.5 S 7 Accra (Ghana) 0.2 W 5.6 N 8 Malindi (Kenya) 40.2 E 3.0 S 9 Male (Maldives) 73.7 E 3.6 N 10 Singapore *103.8 E 1.3 N 11 Koror (Palau) E 7.3 N

Vibration Test Lincoln Lab - MIT August 1999

Thermal Vacuum Test Lincoln Lab - MIT August-September 1999

Primary Ground Station in Singapore National University of Singapore

Launch in January 2000 zThe HETE-2 is scheduled to be launched in January 2000 from Kwajalein, Republic of the Marshall Islands.

ROTSE Robotic Optical Transient Search Experiment OPTICS Canon 200 mm focal length, f/1.8, telephoto lenses in FD mounts IMAGER Apogee Instruments AP-10 CCD cameras with Thomson 2048 x micron imagers. Estimated readout noise: 25 e- at 1.0 Megapixels/sec. University of Michigan. Los Alamos National Laboratory Lawrence Livermore National Laboratory

Optical Flash! Up to 9 mag UTC exposure m_v 9:47: secs :47: secs :47: secs :51: secs :54: secs :57: secs

ROTSE (Optical) BATSE (gamma-ray) GRB : Optical Transient

ROTSE-II ROTSE-II is a set of twin 0.45 meter aperture, f/1.9 telescopes to be operated in stereo mode. Apogee Instruments AP-10 CCD cameras with Thomson 2048 x micron imagers. Estimated readout noise: 25 e- at 1.0 Megapixels/second.

LOTIS Livermore Optical Transient Imaging System z2 x 2 array of Canon EF 200 mm f/1.8L telephoto lenses w/ Loral 442A 2k x 2k CCDs as the imaging sensors. zEach focal plane area of 3.1 cm x 3.1 cm --- a field-of-view for each camera of 8.8° x 8.8°. zThe total field-of-view for the telescope array (allowing for overlap) is therefore 17.4° x 17.4°. zThe CCD pixel size of 15 μm x 15 μm results in a pixel resolution of 15 arcsec.

Super-LOTIS zTelescope: Boller & Chivens 0.6 meter f/3.5 reflector w/ computer controllable motor drive. zImager: a Loral 442A 2048 x 2048 CCD (15 x 15 micron pixels) with LLNL built readout electronics. The CCD is cooled with thermoelectric cooler (to -30 degrees C). zField-of-View: 0.84 x 0.84 degree field-of-view (1.5 arcsec/pixel). zResolution - < 1.5 arcsec zSensitivity - V ~ 19 (10 s), V ~ 21 (60 s) at -30 deg C zSlew Speed - 5 deg/s

RIBOTS ＲＩｋｅｎ - Ｂｉｓｅｉ Ｏｐｔｉｃａｌ Ｔｒａｎｓｉｅｎｔ Ｓｅ ｅｋｅｒ z 望遠鏡 LX シュミットカセグ レン z 口 径 300mm z 焦点距離 1000mm (0.33 倍 RD 使用 ) z 視 野 47.2 ‘X 31.4‘ z 導入速度 秒速 6° z 冷却ＣＣＤ ST8E (KAF1600E) z 画素数 1530x1020 (160 万画素 ) z ２ × ２ ： ７６５ × ５１０ 角度分解能 ３． ７ “ z ３ × ３ ： ５１０ × ３４０ 角度分解能５． ６ “ z 波長帯 350 ～ 925nm (QE > 20%) z フィルターなし RIBOTS Specification

Swift Catching Gamma Ray Bursts on the Fly #Multiwavelength gamma ray burst observatory #Science !Determine origin of GRBs !Use GRBs to probe the early Universe #Three instruments !Gamma-ray camera !X-ray Telescope !UV and Optical Telescope #Rapidly re-pointing “swift” spacecraft !20-70 s response

Swift Mission Features #Rapid response satellite ! sec to slew within FOV of BAT "autonomous operations "factor 100 improved response time "continue monitoring of fading afterglow

Swift Instrumentation zReal time gamma ray burst positions yhalf coded FOV 2 steradians y5200 cm 2 CdZnTe pixel array y keV band ybased on Integral Imager design y5 times more sensitive than BATSE y~ 1 burst per day detected (depends of logN-logS extrapolation) yangular resolution of 22 arcmin giving positions of 1-4 arcmin yonboard processing to provide prompt arc- minute position to satellite ACS and to the ground Burst Alert Telescope (BAT) BAT CdZnTe detector module

Swift mission summary zPI: N. Gehrels (GSFC) zNarrow Field Instruments - Penn State lead X-ray Telescope & Focal Plane (XRT) - Penn State/Leicester/Brera UV/Optical Telescope (UVOT) - MSSL/Penn State/UCSB zBurst Alert Telescope (BAT) - GSFC lead Camera and mask - GSFC Onboard processing - Los Alamos zLEO orbit, 600 km circular 19 degree inclination yLaunch date 2003 yThree-year mission operation life yOrbit stable for 5+ years without propulsion

Space Missions Capable of Localizing Gamma-Ray Bursts Missionloc/yraccuracydelayoperating period BeppoSAX101—10 arcmin hourspresent — 2001? CGRO BATSE300>4°5 secpresent — 2002? 100>1.6°15 min Interplanetary705’x 10°~1 daypresent —2001? network (IPN ） 1’x 20’ RXTE ASM410 arcminhourspresent — 2002? HETE-2 WXM3010 arcmin~10 sec2000 —2001 SXC1610 arcsec INTEGRAL IBIS20arcminutes~10 sec2001—2003 Swift BAT3001—4 arcmin12 seconds2003(2004)—2010 XRT~arcsec50—70 sec UVOT0.3 arcsec200 sec GLAST (>100 MeV)5010 arcmin2005— (GBM)(200)(arcmin-arcsec)(10—300 sec)