Bright gamma-ray burst GRB 080319 B Credit NASA Swift Mary

Bright gamma-ray burst, GRB 080319 B Credit: NASA/Swift/Mary Pat Hrybyk-Keith and John Jones Ultra-Fast Flash Observatory for detecting the early photons from Gamma Ray Bursts International Workshop on Nuclear, Particle and Astrophysics Yongpyong, Feb. 21 -25, 2010 Heuijin Lim (IEU/Ewha Womans Univ. ) Heuijin Lim Feb. 22. 2010 1

UFFO Collaboration (until Dec. 2009) J. A. Jeon 1, A. R. Jung 1, S. M. Jeong 1, J. E. Kim 1, H. Y. Lee 1, J. Lee 1, G. W. Na 1, J. W. Nam 1, S. Nam 1, I. H. Park 1, 6, J. E. Suh 1 1 Research Center of MEMS Space Telescope (RCMST), Ewha Womans University, Seoul 120 -750, Korea S. Boggs 3, B. Grossan 2, 3, E. V. Linder 2, 3, 6, G. F. Smoot 2, 6 2 Berkeley Center for Cosmological Physics (BCCP), University of California, Berkeley, California 94720, USA 3 Space Sciences Laboratory, University of California, Berkeley, California 94720, USA B. A. Khrenov 4, G. K. Garipov 4, M. Panasyuk 4, P. Klimov 4 4*D. V. Skobeltsyn Institute of Nuclear Physics (SINP), Moscow State University, Moscow 119992, Russia C. -H. Lee 1, 5 5 Department of Physics, Pusan National University, Pusan 609 -735, Korea Y. -Y. Keum 1, 6, H. Lim 6, Z. L. Uhm 1, 6, J. Yang 6 6 Institute for Early Universe (IEU), Ewha Womans University, Seoul 120 -750, Korea J. H. Park 1, 7 7 Department of Electrical Engineering, Dan-Kuk University, Kyungkee 200 -200, Korea J. Y. Jin 1, 8, Y. K. Kim 8, B. W. Yoo 1, 8 8 School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151 -600, Korea Y. -S. Park 1, 9, H. J. Yu 1, 9 9*School of Physics and Astronomy, Seoul National University, Seoul 151 -742, Korea S. W. Kim 10 10*Korean Astronomy and Space Science Institute, Daejeon 200 -200, Korea Pisin Chen 12, 13, C. -K. Huang 12 , M. Huang 12 12 Leung Center for Cosmology and Particle Astrophysics & Department of Physics and Graduate Institute of Astrophysics, National Taiwan University, Taipei, Taiwan 10617 13 Kavli Institute of Particle Astrophysics and Cosmology, Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94305, USA Y. -H. Chang 14 14 Department of Physics, National Central University, Jung-Li 32001, Taiwan M. -H. Huang 15 15 Department of Energy and Natural Resource, National United University, Miao-Li 36003, Taiwan Heuijin Lim Feb. 22. 2010 2

q Gamma Ray Burst (GRB) Physics q GRB Missions q New approach & Space Heritage q UFFO Instruments UFFO Pathfinder Full UFFO q Summary Heuijin Lim Feb. 22. 2010 3

Gamma Ray Bursts GRB 990123 – Hubble Space Telescope From Fruchter et al. 1999 • Brightest explosions in Universe – 1051 erg in few x 10 sec flash • Standard candles? – Early universe probes! • progenitors? – Black hole birth At z = 8. 2, Epoch of “reionization”. Last phase of cosmic evolution to be explored. Heuijin Lim Feb. 22. 2010 Collapsar Model 4

GRB Missions BATSE (1991) (Burst and Transient Source Experiment) HETE-2 (2000) SWIFT (2004) (High Energy Transient NASA’s MIDEX mission Explorer-2) only GRB dedicated mission UFFO Pathfinder (~2011 Nov. ) Fermi Gamma-ray Space Telescope (2008) Heuijin Lim Feb. 22. 2010 5

Science Motivation of UFFO Afterglow discoveries Swift observatory : Spacecraft slews XRT & UVOT to GRB in < 100 s GRB 050525 A UVOT of SWIFT ? 70 sec before Tracking Mirror telescope is capable of providing a data down to “a few second” Feb. 22. the trigger of burst after 2010 Heuijin Lim 6

Fireball Model Heuijin Lim Feb. 22. Early Gamma-X light curves with multiple peaks were measured : Indicate the presence of internal shock, producing prompt emission. UV/optical emission at early time is believed to be from external shocks. But, they also could be from internal shocks! Need to measure them at the beginning time after trigger and 2010 7 with shorter time scale.

Panaitescu, A. & Vestrand, W. , 2008, MNRAS 387, 497 Variation in optical light curves Fast rising • six fast-rising (Fo t 2. 5± 0. 5), peaking at ~100 s, • five slow-rising (Fo t 0. 6± 0. 2), peaking after 100 s, • 12 with fast decays (Fo t-1. 0± 0. 3), since 100 s, • six with plateaus (Fo t-0. 2± 0. 1), last for one to two decades in time. Heuijin Lim Feb. 22. 2010 Slow rising 8

Classification of GRBs Hard GRBs measured by BASTE Long-soft GRBs • Afterglow observation • Type Ib/c SN association Progenitor : Massive Star • median Redshift ~ 2. 5 • Optically Bright Short-hard GRBs Soft Hardness Ratio: (100 -300 ke. V) / (50 -100 ke. V) Long Short T 90 < 2 s • X-ray afterglows • Optical afterglows detected by a handful GRBs. Also optically Faint. Not clear for the optical mechanism! • No SN association (? ) Progenitor : NS-BH, NS-NS. • median Redshift ~ 0. 25 Dark GRBs : maybe due to Heuijin Lim Feb. 22. 2010 faded out too fast(? ) 9 T 90 : duration time encompassing the 5% to 95% of total counts

New Approach & Space Heritage Heuijin Lim Feb. 22. 2010 10

UFFO (Ultra Fast Flash Observatory ): Tracking Mirror Telescope q A NEW APPROACH: Move the optical path, not the spacecraft. q Micromirror array tilts light quickly within FOV of telescope. q Rapid afterglow follow-up and identifying GRB environment by using fast rotatable micromirror array – Fast slewing of viewing angle within the first few milliseconds after triggering Heuijin Lim Patent : 22. 2010 Feb. 10 -0921433, 10 -0921434, 10 -0888080, 10 -0888076, 1011 0894526,

Ewha’s MEMS Micromirror Array mirror plate comb actuator (mirror plate removed) MEMS (Micro-Electro-Mechanical Systems) Micromirror Array (MMA) • Hidden actuators. • Driven by two-axis electrostatic vertical comb actuator. Large tilt angle and Fast rotation speed • High fill-factor of 84 % in an 8 x 8 array • Reflector: 340 µm x 340 µm ( used for MTEL) Heuijin Lim Feb. 22. 2010 12

Space qualification • Maximum tilt angle: 7. 5° (outer axis rotation) ± 15° • Fast response ~ 500 μs Operated in the International Space Station (ISS), (April 11 -17, 2008) Micromirror toggle on/off test (Test with one-axis MEMS micromirror) Instrument Before launching Heuijin Lim Feb. 22. 2010 In the ISS 13

First MEMS Tracking Mirror Telescope TLE (Transient Luminous Events) • World first, wide FOV, fastest zoom-in and tracking 28 domestic and foreign patents. 5 papers including Optics Express 16(2008) 20249 Introduced in Laser Focus World Feb. 2009 Heuijin Lim • Russian Microsatellite Tatyana-2 Launched in Sep. 2009. • Payload: MTEL (MEMS Telescope for Extreme Lightning), 3 x 3 mm 2 aperture. It is a Small prototype of UFFO. 14 Feb. 22. 2010

MTEL is on the Orbit now! Launched, Sep 18 th 2009, Baikonor MTEL Tatiana 2 Satellite Heuijin Lim First Data: Oct. 21 st 2009. All channels are Feb. 22. 2010 well working 15

UFFO Pathfinder Heuijin Lim Feb. 22. 2010 16

UFFO Pathfinder Payload 300 mm (h) SMT (Slewing Mirror Telescope) (d) m 75 m UBAT (UFFO Burst Alert & (X-ray) Trigger telescope) Trigger fired 6 UBAT SMT (Slewing Mirror Telescope) X-ray Data 68 UV/Optical-ray Data 0 Processing Data m d ) (w h m zenith w Heuijin Lim Feb. 22. 2010 17

UFFO Burst Alert & Trigger Telescope Coded mask aperture camera Total size 1024 cm 2 Compounds Ta-W alloy Distance to 25 cm detector Detector plane Compounds Cd. Te Effective size 307 cm 2 Pixel size 1. 2 x 1 mm 3 Number of pixels 146 x 146 • • • Mass ~ 20 kg Energy range : 4 ~ 250 ke. V Telescope PSF : ≤ 17 arcmin FOV ~2 sr (89°x 89°) 67 GRBs/year Spectral energy ≤ 2 ke. V FWHM at resolution 60 ke. V Sensitivity 310 m. Crab in 10 s exposure at 5. 5σ 4~50 ke. V For source location recognition, processing time using the Heuijin Lim Feb. 22. ms. 18 advanced FPGA will be a few hundred 2010

Slewing Mirror Telescope Fast rotatable mirror plate covered by MEMS mirror arrays (MMA) rotation angle is ± 15° Telescope Ritchey-Chrétien + MMA with motorized plate Aperture 20 cm diameter F-number 6 FOV 17 x 17 armin Detector Intensified CCD with MCP Detection Element 256 x 256 pixels Pixel Scale 4 arcsec Location Accuracy 0. 5 arcsec Wavelength Range 200 nm ~ 650 nm Sensitivity • Data Rate ~ 1 Gbytes/day • Mass ~ 20 kg • Power ~ 20 W Heuijin Lim B=23. 5 in white light in 1000 sec. Bright Limit mv = 6 mag Feb. 22. 2010 19

Execution plan Short + Long GRBs Short-hard GRBs 67 UVOT Bursts/year triggered by UBAT. BAT Fluence 15 -150 ke. V, 10 -7 erg cm-2 Swift BAT : 10 -1 x (BAT Fluence) • Studied using the Swift gamma-X fluence for the period 2005 Jan. 24 ~ 2009 Sep. 21 • UBAT sensitivity is ~ 10 x poor than SWIFT BAT. Fraction of bursts lost is small (~10 %). Heuijin Lim Feb. 22. 2010 20

UFFO Pathfinder spacecraft Lomonosov satellite is processed under the Russian federal space program. Payload : TUS + UFFO Pathfinder Name of Spacecraft Lomonosov Platform Provider VNIIEM Launch Date Expected Nov. 2011 Orbit Height 500 ~ 600 km Total Mass 300 ~ 800 kg Mission Lifetime 3 years Payload TUS for observation of Ultra High Energy Cosmic Ray and UFFO Pathfinder for GRBs Total Payload Mass 100 ~ 150 kg (TUS: 80 kg, UFFO: 30 ~ 60 kg) Total Payload Power 100 ~ 150 W Heuijin Lim Feb. 22. 2010 21

Lomonosov Satellite Space viewing UFFO here Earth viewing TUS telescope Heuijin Lim Feb. 22. 2010 22

Full UFFO Heuijin Lim Feb. 22. 2010 23

Full UFFO Payload UBAT (UFFO Burst Alert & (X-ray) Trigger telescope) UTAT (UV/Optical Trigger Assistant Telescope) 950 mm 500 mm Position ON/OFF 1090 mm Gamma ray Monitor Energy Meas. Heuijin Lim Processing Data Feb. 22. 2010 SMT (Slewing Mirror Telescope) Precise position 24

Design parameters of Full UFFO Parameters UBAT (X-ray for primary trigger) UTAT (UV for SMT (UV-optical for secondary trigger) afterglow) Telescope Concept Coded mask Aperture Coded mask: 51 x 95 cm 2 30 x 30 cm 2 Detector: 20 x 40 cm 2 30 cm diameter FOV 2. 0 sr 60° x 60° (pixel FOV = 0. 1° x 0. 1°) 0. 3° x 0. 3° (pixel FOV= 4″x 4″) # of channels > 5, 000 ~600 x 600 ~256 x 256 Exposure time 1 s 100 ms 1 s (for 17. 5 mag) Location Accuracy 17 arcmin. ~3 arcmin. ~ 0. 5 arcsec. Energy range 4 ~ 250 ke. V 200 ~ 650 nm Focal plane detector Cd. Te Si. PM or Intensified CCD Total processing time 1. 1 s Readout~20 ms Total Time ~ 0. 12 s Motor slewing ~ 2 s Readout ~ 50 ms Total Time ~ 2. 1 s Heuijin Lim Double Fresnel Lens Feb. 22. 2010 Ritchey-Chrétien + MMA with motorized plate 25 If UV/optical photons are from GRBs, they will be detected within 4 s.

Readout/Trigger/Control Architecture ES Event Summary Power Generation Board CCU Central Control Unit SI Satellite Interface MCL Mirror Control Logic UFFO UBAT UTAT GRM HKC TPU House Keeping Control SMT Trigger Processing Unit 8 bit LUT DAC FCL Fifo Control Logic data Run Summary Heuijin Lim Memory (FIFO) MEMS Micromirror Array Analog Front-End ADC MUX Cd. Te ( > 5, 000 Chs ) Preamp Si. PM ( 360, 000 Chs ) Analog Front-End 10 bit ADC Feb. 22. 2010 Crystal detector + PMT ICCD ( 256 x 256 Chs ) 26

Payload Parameters and Collaboration • • • Physical size: 95 x 109 x 50 Mass: 120 kg Power: 200 W Data: 110 kbps Launch: 2013 ~ 2015 cm 3 Platform • NASA microsatellite (SALMON) • France • Russia VNIIEM • Korean KSNL-1 or 2 Heuijin Lim Feb. 22. 2010 Present • Ewha RCMST, IEU • PNU, SNU, DKU, KASI • Berkeley BCCP • Berkeley SSL • NASA-AMES Future • KARI • Others (Taiwan, Russia, Japan, Denmark, etc. ) 27

Summary Fast detection of UV/optical photons from optical transients is quite challenging. Rarely the prompt UV/optical emission has been measured within sub-minute after X-ray trigger, never at subsecond scale. • Measurement of early photons will permit measuring or constraining internal/external shock emission. • Measurement of the short GRBs (and the dark GRBs) with the shorttime scale Finally, they will provide the key information to understand the GRB mechanism, progenitor etc. 1. We proposed the Slewing Mirror Telescope for sub-minute/sub -second measurements. 2. UFFO Pathfinder with a 20 -cm aperture SMT and X-ray trigger Launch on the Lomonosov spacecraft foreseen in Nov. 2011. 3. Full UFFO is expected in 2014. Heuijin Lim Feb. 22. 2010 28

Welcome to join the UFFO Collaboration! Heuijin Lim Feb. 22. 2010 29

ar. Xiv: 0806. 3607 Short GRB 060313 Short GRBs X-ray αSGRB≤αLGRB Early X-ray α = -1. 25 +- 0. 15 Late X-ray α=-1. 46+-0. 08 Early UV α=-0. 13± 0. 28 Late UV, α=-0. 43+-0. 13 • Flux ~ tα(afterglow photon index) • Afterglow has been measured after 11 hours. • A few of Short GRBs have been detected. Optical-ray was detected in ≤ 50 % SGRBs. Different light-curves between X-ray and optical photons. between Short GRBs and Long GRBs. Feb. 22. !Heuijin Lim detect the more Short GRBs ! 2010 Need to Optical αLGRB<αSGRB Only 5 Short GRB with Optical! 30