Observation of Crab Nebula by Nuclear Compton Telescope (NCT)

Transcription

1 Observation of Crab Nebula by Nuclear Compton Telescope (NCT) 32 nd ICRC, Aug.15, 2011 at Beijing, China Ming-Huey A. Huang for NCT Collaboration National United University & LeCosPA, NTU NCT Collaboration: Berkeley, NTHU, NCU, NSPO, NUU, LBNL, CESR

2 The NCT 09 Team Goals of 2009 balloon flight: Qualify for LDBF from Australia Image Crab, if possible verify its polarization S.E. Boggs (PI), C.B. Wunderer, A. Zoglauer, M. Bandstra, E. Bellm, D. Perez-Becker, (UCB/SSL, USA) H.-K. Chang (Co PI), J.-L. Chiu, J.-S. Liang (NTHU, Taiwan) Y.-H. Chang, Z.-K. Liu, W.-C. Hung (NCU, Taiwan), C.-H. Lin (Academia Sinica, Taiwan),, R.-S. Run (NUU, Taiwan), M. Amman, P. N. Luke (LBNL, USA) P. Jean M.A. (CESR, Huang France) Supported by grants from NASA, USA and NSPO, Taiwan

3 NCT Science Goals Positron astrophysics (0.511 MeV) SNe gamma-ray lines 26 Al (1.809 MeV) 60 Fe (1.173,1.333 MeV) 44 Ti (1.157 MeV) Compact objects AGN Black holes Neutron stars GRBs Gamma-ray polarization COMPTEL 26 Al all-sky map INTEGRAL / SPI 511 kev Line Skymap Richardson-Lucy, Smoothed Knödlseder et al. 2007

4 NCT Instrument Electronics Bay Instrument cradle Dewar preamps BGO shields Ge detectors Cryostat BGO PMTs signal cables 10x Cross Strip 3-D GeDs 37x37 strips 81 cm 3 volume

5 Record breaking flight May 17~19, 2009, launch from Fort Sumner, NM, USA. 38 hours at float altitude Qualify for long duration flight! Detect the first image of Crab by the new generation Compton telescopes!

6 Collection Time Difference (CTD) CTD histogram of a single pixel (AC 9, DC 2), showing events that are energy-selected to be photo-absorptions of 59.5 kev photons. Charge transport simulation: to convert CTD to depth (Z). Jeng-Lun Chiu, et al.,(10/2009) Energy, Depth Calibration, and Imaging Capability of the Nuclear Compton Telescope, IEEE Nuclear Sci. Symp. Conf. Rec. 2009, N13-70.pdf

7 Calibration Energy resolution Two 137 Cs sources that are ~10 away CTD distribution Calibration data Jeng-Lun Chiu, et al.,(10/2009) Energy, Depth Calibration, and Imaging Capability of the Nuclear Compton Telescope, IEEE Nuclear Sci. Symp. Conf. Rec., 2009, N13-70.pdf Simulation

8 Field of View Calibration FOV is 20 ~ +40 in backward-forward direction (~ zenith angle θ ) and ± 40 in sideway (~azimuth angle φ ). Effective Area vs. Modified Zenith Effective Area (Selection-2) (cm^2) E < 1.4σ, CSL: Modified Zenith (degree) (Simulated) 0662-keV [dat] 1173-keV [dat] 1333-keV [dat] 0662-keV [sim] 1173-keV [sim] 1333-keV [sim] Jeng-Lun Chiu, for the NCT collaboration, Ground calibrations of Nuclear Compton Telescope, Proc. SPIE 77324H, (2010), DOI: /

9 Calibration 137 Cs spectrum Field of view test: radioactive source at 20 from zenith. 60 Co spectrum E. Bellm, et al.,(10/2009), Efficiency and Polarimetric Calibrations of the Nuclear Compton Telescope, IEEE Nuclear Sci. Symp. Conf. Rec., 2009, N13-57.pdf

10 Targets for May 2009 flight Source Crab 3C273, 3C279, NGC4151 Cas A Cyg X1 Exposure Time 11 hr 5.6 hr 0.9 hr 0.9 hr FOV display

11 NCT 09 flight data analysis Raw spectra during the flight while observing the Crab nebula on May 17, site events 3-7 site events MeV e+ line Background from Al in solar shield Jeng-Lun Chiu, PhD thesis, NTHU, 2010

12 Image of Crab The Crab was detected at a significance of at least 4σ by NCT during the 2009 balloon flight. First image of crab by the New Generation Compton telescopes! M. S. Bandstra, et al., Detection and Imaging of the Crab Nebula with the Nuclear Compton Telescope, ApJ doi: / X/738/1/8

13 Different approach Veto the most noisy detectors D0, D1, D8, and D9. X X X X back projection only. image reconstruction Jau-Shiang Liang, PhD thesis, NTHU, 2010

14 Polarization Scattered electron from 100% Polarized γ of 0.5 MeV. (Zenith angle θ are plotted in radial distance in this polar plot. The center θ=0 is the forward direction of photon. The azimuth angle is electric field direction. Color code is dσ/dω) Klein Nishina differential cross-section for a polarized photon beam Jau-Shiang Liang, PhD thesis, NTHU, 2010

15 Polarization Measurement Measured polarization angle Preliminary result: Polarization = 41.2 ± 3.6 % Simulateded angle from unpolarized beam E. Bellm, et al.,(10/2009), Efficiency and Polarimetric Calibrations of the Nuclear Compton Telescope, IEEE NSS 2009, N13-57.pdf

16 NCT 09 Flight Spectrum Preliminary! Jeng-Lun Chiu, PhD thesis, NTHU, 2010

17 Summary NCT performed two balloon flights in 2005 and 2009 and qualify for future long duration flight. NCT 09 flight observed image of the Crab nebula and possible polarization. Data analysis are still on-going. Due to launch failure in 2010, NCT will be rebuilt and may fly again in APCosPA-2011

18 Some publications M. S. Bandstra, for NCT collaboration, (9/01/2011) Detection and Imaging of the Crab Nebula with the Nuclear Compton Telescope, Astrophys. J., 738, 8; doi: / X/738/1/8 Wei-Che Hung, for the NCT collaboration, (6/2009), The Data Readout System of the Nuclear Compton Telescope (NCT), IEEE Trans. Nucl. Sci., 56: Bellm, E.C. for NCT collaboration, (6/2009) Overview of the Nuclear Compton Telescope, IEEE Trans. Nucl. Sci., 56: M. S. Bandstra, et al.,(10/2009), The Spring 2009 Balloon Flight of the Nuclear Compton Telescope, IEEE Nuclear Science Symposium Conference Record, 2009, N37-3.pdf Ming-Huey A. Huang, et al.,(7/2009)the Nuclear Compton Telescope (NCT): a status report after 2009 balloon flight, Proceedings of the 31st ICRC, Lodz, 2009, #0952 Huang, M. A., Chiang, S.J., Run, R.S. NCT Solar Power System, proc. of the 4 th Asian Space Conference, (Oct, 1-3, 2008, Taipei, Taiwan)

19 NCT 2010 flight at Alice Spring, Australia Launch attempt in Apr. 29, Payload fail to launch, crash to ground, NCT gondola destroyed.

20 Launch failure Launch attempt in Apr. 29, 2010 at Alice Spring, Northern Territory, Australia, Payload fail to launch, crash to ground, NCT gondola destroyed. 12/09/2010