Skip to main content
SpringerLink
Log in

Prospects of hard X-ray polarimetry with Astrosat-CZTI

  • Original Article
  • Published:
Experimental Astronomy Aims and scope Submit manuscript

Abstract

Astrosat is the first Indian satellite mission dedicated for astronomical studies. It is planned for launch during 2014 and will have five instruments for multi-wavelength observations from optical to hard X-rays. Cadmium Zing Telluride Imager (CZTI) is one of the five instruments aiming for simultaneous X-ray spectroscopy and imaging in the energy range of 10 keV to 100 keV (along with all sky photometric capability unto 250 keV). It is based on pixilated CZT detector array with total geometric area of 1024 cm2. It will have two-dimensional coded mask for medium resolution X-ray imaging. The CZT detector plane will be realized using CZT detector modules having integrated readout electronics. Each CZT detector module consists of 4 cm × 4 cm CZT with thickness of 5 mm which is further pixilated into 16 × 16 array of pixels. Thus each pixel has size of 2.5 mm × 2.5 mm and thickness of 5 mm. Such pixilated detector plane can in principle be used for hard X-ray polarization measurements based on the principle of Compton scattering by measuring azimuthal distribution of simultaneous events in two adjacent pixels. We have carried out detailed Geant4 simulations for estimating polarimetric capabilities of CZTI detector plane. The results indicate that events in the energy range of 100 keV to 250 keV, where the 5 mm thick CZT detector has significant detection efficiency, can be used for polarimetric studies. Our simulation results indicate the minimum detectable polarization (MDP) at the level of ∼ 10% can be achieved for bright Crab like X-ray sources with exposure time of ∼500 ks. We also carried out preliminary experiments to verify the results from our simulations. Here we present detailed method and results of our simulations as well as preliminary results from the experimental verification of polarimetric capabilities of CZT detector modules used in Astrosat CZTI.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16

Similar content being viewed by others

References

  1. Agrawal, P.C.: A broad spectral band Indian astronomy satellite Astrosat. Adv. Space Res. 38, 2989–2994 (2006)

    Article  ADS  Google Scholar 

  2. Bloser, P.F., Legere, J.S., McConnell, M.L., Macri, J.R., Bancroft, C.M., et al.: Calibration of the gamma-ray polarimeter experiment (GRAPE) at a polarized hard X-ray beam. NIMPA 600, 424–433 (2009)

    Article  ADS  Google Scholar 

  3. Chattopadhyay, T., Vadawale, S.V., Pendharkar, J.: Compton polarimeter as a focal plane detector for hard X-ray telescope: sensitivity estimation with Geant4 simulations. Exp. Astron. 35, 391–412 (2013)

    Article  ADS  Google Scholar 

  4. Costa, E., Soffitta, P., Bellazzini, R., Brez, A., Lumb, N., et al.: An efficient photoelectric X-ray polarimeter for the study of black holes and neutron stars. Nature 411, 662–665 (2001)

    Article  ADS  Google Scholar 

  5. Dean, A.J., Clark, D.J., Stephen, J.B., McBride, V.A., Bassani, L., et al.: Polarized gamma-ray emission from the Crab. Science 321, 1183 (2008)

    Article  ADS  Google Scholar 

  6. Geant4 Collaboration, Agostinelli, S., Allison, J., Amako, K., et al: Geant4-a simulation toolkit. NIMPA 506, 250–303 (2003)

    Article  ADS  Google Scholar 

  7. Gowen, R.A., Cooke, B.A., Griffiths, R.E., Ricketts, M.J.: An upper limit to the linear X-ray polarization of SCO X-1. MNRAS 179, 303–310 (1977)

    Article  ADS  Google Scholar 

  8. Griffiths, R.E., Ricketts, M.J., Cooke, B.A.: Observations of the X-ray nova A0620-00 with the Ariel V crystal spectrometer/polarimeter. MNRAS 177, 429–440 (1976)

    Article  ADS  Google Scholar 

  9. Guo, Q., Beilicke, M., Garson, A., Kislat, F., Fleming, D., et al.: Optimization of the design of the hard X-ray polarimeter X-Calibur. Astropart. Phys. 41, 63–72 (2013) doi:10.1016/j.astropartphys.2012.11.006

  10. Harrison, F.A., Craig, W.W., Christensen, F.E., Hailey, C.J., Zhang, W.W., et al.: The Nuclear Spectroscopic Telescope Array (NuSTAR) high energy X-ray emission. ApJ 770, 103–121 (2013)

    Article  ADS  Google Scholar 

  11. Heitler,W.: The Quantum Theory of Radiation, 3rd edn. Oxford University Press, Oxford (1954)

    Google Scholar 

  12. Hughes, J.P., Long, K.S., Novick, R.: A search for X-ray polarization in cosmic X-ray sources. ApJ 280, 255–258 (1984)

    Article  ADS  Google Scholar 

  13. Jahoda, K.: The gravity and extreme magnetism small explorer. In: Proceedings SPIE Conference, vol. 7732 (2010)

  14. Krawczynski, H., Garson, A., Guo, Q., Baring, M.G., Ghosh, P., et al.: Scientific prospects for hard X-ray polarimetry. Astropart. Phys. 34, 550–603 (2011)

    Article  ADS  Google Scholar 

  15. Laurent, P., Rodrigues, J., Wilms, J., Cadolle Bel, M., Pottschmidt, K., et al.: Polarized gamma-ray emission from the galactic black hole Cygnus X-1. Science 332, 438 (2011)

    Article  ADS  Google Scholar 

  16. Lei, F., Dean, A.J., Hills, G.L.: Compton polarimetry in gamma-ray astronomy. Space Sci. Rev. 82, 309–388 (1997)

    Article  ADS  Google Scholar 

  17. Nandi, A., Palit, S., Debnath, D., Chakrabarti, S.K., Kotoch, T.B., et al.: Instruments of RT-2 experiment onboard CORONAS-PHOTON and their test and evaluation III: coded aperture mask and Fresnel Zone Plates in RT-2/CZT payload. Exp. Astron. 29, 55–84 (2011)

    Article  ADS  Google Scholar 

  18. Novick, R., Weisskopf, M.C., Berthelsdorf, R., Linke, R., Wolff, R.S.: Detection of X-ray polarization of the Crab nebula. ApJL 174, L1 (1972)

    Article  ADS  Google Scholar 

  19. Orsi, S. et al.: POLAR: A space-borne X-Ray polarimeter for transient sources. ASTRA 7, 43–47 (2011)

    ADS  Google Scholar 

  20. Silver, E.H., Weisskopf, M.C., Kestenbaum, H.L., Long, K.S., Novick, R., et al.: The first search for X-ray polarization in the Centaurus X-3 and Hercules X-1 pulsars. ApJ 232, 248–254 (1979)

    Article  ADS  Google Scholar 

  21. Soffitta, P., Costa, E., Muleri, F., Campana, R., Del Monte, E., et al.: A set of x-ray polarimeters for the new hard X-ray imaging and polarimetric Mission. In: Proceedings SPIE Conference, vol. 7732, 2010.

  22. Turler, M., Chernyakova, M., Courvoisier, T., Lubinski, P., Neronov, A., et al.: INTEGRAL hard x-ray spectra of the cosmic x-ray background and galactic ridge emission. Astron. Astrophys. 512, 181 (2010)

    Article  Google Scholar 

  23. Vadawale, S.V., Chattopadhyay, T., Pendharkar, J.: A conceptual design of hard X-ray focal plane detector for simultaneous x-ray polarimetric, spectroscopic, and timing measurements. In: Proceedings SPIE Conference, vol. 8443 (2012)

  24. Vadawale, S.V., Hong, J.S., Masui, H., Grindlay, J.E., Williams, P., et al.: Multipixel characterization of imaging CZT detectors for hard x-ray imaging and spectroscopy. In: Proceedings SPIE Conference, vol. 5540 (2004)

  25. Vadawale, S.V., Purohit, S., Shanmugam, M., Acharya, Y.B., Goswami, J.N., et al.: Characterization and selection of CZT detector modules for HEX experiment onboard Chandrayaan-1, Vol. 598, pp. 485–495 (2009)

  26. Vadawale, S.V., Sreekumar, P., Acharya, Y.B., Shanmugam, M., Banerjee, D., et al.: Hard X-ray continuum from lunar surface: results from high energy X-ray spectrometer (HEX) onboard Chandrayaan-1. In: Advances in Space Resarch. Accepted for Publication (2014). doi: 10.1016/j.asr.2013.06.013

  27. Weisskopf, M.C., Silver, E.H., Kestenbaum, H.L., Long, K.S., Novick, R.: A precision measurement of the X-ray polarization of the Crab nebula without pulsar contamination. ApJL 220, L117–L121 (1978)

    Article  ADS  Google Scholar 

  28. Yonetoku, D., Murakami, T., Masui, H., Kodaira, H., Aoyama, Y., et al.: Development of polarimeter for gamma-ray bursts onboard the solar-powered sail mission. In: Proceedings SPIE Conference, vol. 6266 (2006)

Download references

Acknowledgements

Research at Physical Research Laboratory, Ahmedabad is supported by the Department of Space, Government of India. The authors thank the technical assistance provided by the CZT-Imager team at TIFR as well as at IUCAA.

Author information

Authors and Affiliations

  1. Astronomy and Astrophysics Division, Physical Research Laboratory, Ahmedabad, India

    T. Chattopadhyay & S. V. Vadawale

  2. Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai, India

    A. R. Rao

  3. Baseband Systems Electronics Division, Vikram Sarabhai Space Centre, Thiruvananthapuram, India

    S. Sreekumar

  4. The Inter-University Centre for Astronomy and Astrophysics, Pune, India

    D. Bhattacharya

Authors
  1. T. Chattopadhyay
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. S. V. Vadawale
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. R. Rao
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. S. Sreekumar
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. D. Bhattacharya
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to T. Chattopadhyay.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Chattopadhyay, T., Vadawale, S.V., Rao, A.R. et al. Prospects of hard X-ray polarimetry with Astrosat-CZTI. Exp Astron 37, 555–577 (2014). https://doi.org/10.1007/s10686-014-9386-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10686-014-9386-1

Keywords

Search

Navigation