Osservatorio Astronomico di Palermo Giuseppe S. Vaiana


X-ray Astronomy

X-ray astronomy is far more recent than optical astronomy and supplies unique data on the physics and history of the universe. As the X-radiation from space is prevented from reaching the Earth by the atmosphere, it is necessary that in order to detect X-rays, instruments are brought beyond the atmosphere.

From rockets to orbiting observatories

Back in the 60s, the first experimental observations of celestial X-ray sources employed rockets as a means to maintain the X-ray detectors at a high enough altitude to detect radiation for a few minutes. These experiments were aimed at confirming the scientific value of X-ray observations, as the existence of extra-solar X sources was still unproven. Nowadays X-ray astronomy no longer employs rockets but real orbiting observatories able to observe scan the sky for several years. Rockets, however, are still in use to test the functionality of new generation equipment. Experiments based on orbiting observatories require long preparation times (sometimes over ten years) and involve researchers and institutions from various countries to plan and carry out the mission. Performance testing, calibration and adjustments procedures on the instruments prior to the launch are crucial operations as on these relies the success of the mission and a correct interpretation of the observational data.

The XACT laboratory

In the early 90s at the Palermo Observatory a laboratory was set up, with the purpose of developing and calibrating equipment for X-ray astronomy. At the XACT (X-ray Astronomy Calibrating and Testing) laboratory, pieces of instruments such as filters, detectors and optical parts have been calibrated and tested for use in some of the most important international X-ray astronomy missions of the past 15 years. The OAPA team has achieved specific skills in projecting and calibrating filters used in X-ray astronomy missions. Filters are essential for the proper operation of astronomical X-ray detectors, as they stop visible and UV light and low-energy particles which would otherwise hit the detector, damaging it or reducing its effectiveness. Throughout the years, the laboratory has been expanded and upgraded with advanced equipment, in line with the latest requirements of ongoing space missions. In addition, R&D programs aimed at the development of frontier instrumentation for X-ray astronomy have been started.

In this framework, the initial 18 meter long X-ray beam-line was expanded to 34,5 meters, to better approximate the distance between real X-ray telescope and astronomical sources. A cryostat, able to maintain few tens of mK temperatures has been added to the equipment, and is used for the testing og cryogenic X-ray detectors. A Microtechnologies Laboratory has been set up for developing and manufacturing energy dispersive X-ray detectors. It includes a clean-room and equipment for thin film deposition, electroplating, polishing, spin-coating, chemical etching and micro-photolithography. The devices under development are tested in the Cryogenics Laboratory, equipped with an Adiabatic Demagnetization Refrigerator (ADR) able to maintain few tens of mK temperatures.

Microcalorimeter based X-ray detectors

The project aims at the development of:

In this framework several processes necessary for the fabrication of high density matrices have been developed. These processes, characterized by high uniformity and repeatability, include germanium etching, indium bumps deposition, metal contacts deposition and soldering, absorbers growth.Development of room temperature and low temperature electronics are in progress.

X-ray astronomy instrumentation development and testing

Activities include

Relevant References

  1. Feroci, M., et al., “The Large Observatory for X-ray Timing (LOFT)”, Experimental Astronomy, in press. (2011).

  2. Den Herder, J.W., et al., “ORIGIN: metal creation and evolution from the cosmic dawn”, Experimental Astronomy, in press. (2011).

  3. Tichý, V., Barbera, M., Collura, A., Hrom

  4. ik, M., Hudec, R., Inneman, A., Jakůbek, J., Maršik, J., Maršikovà,V., Pìna, L., Varisco, S., “Tests of lobster eye optics for small space X-ray telescope”, NIMP-A, Vol. 633, p. S169-S171 (2011).

  5. Barbera, M., Mineo, T., Basso, S., Christensen, F.E., den Herder, J.-W., Kaastra, J., Piro, L., Spiga, D., van Baren, C., “The mirror module design for the cryogenic x-ray imaging spectrometer on-board ORIGIN”, Proc. SPIE, Volume 8076, pp. 80760A-80760A-12 (2011)

  6. U. L. Cicero, C. Arnone, M. Barbera, A. Collura, G. Lullo, «Electroplated indium bumps as thermal and electrical connections of NTD-Ge sensors for the fabrication of microcalorimeter arrays,» LTD14, Heidelberg, August, 2011.

  7. U. L. Cicero, C. Arnone, M. Barbera, A. Collura e G. Lullo, «Fabrication of Electrical Contacts on Pyramid-Shaped NTD-Ge Microcalorimeters Using Free-Standing Shadow Masks,» Journal of Low Temperature Physics, 2011.

  8. Macculi, Claudio; Colasanti, Luca; Lotti, Simone; Natalucci, Lorenzo; Piro, Luigi; Bagliani, Daniela; Brunetto, Francesco; Ferrari, Lorenza; Gatti, Flavio; Torrioli, Guido; Bastia, Paolo; Bonati, Arnaldo; Barbera, Marco; La Rosa, Giovanni; Mineo, Teresa; Perinati, Emanuele The TES-based cryogenic anticoincidence detector for IXO: first results from large area prototypes, Proc. SPIE, Volume 7732, pp. 77323Y-77323Y-11 (2010)

  9. Piro, L.; et al., EDGE: Explorer of diffuse emission and gamma-ray burst explosions.   Experimental Astronomy, Volume 23, Issue 1, pp.67-89 (2009)  

  10. Dell'Orto, E.; Barbera, M.; Bulgarelli, A.; Fioretti, V.; Malaguti, G.; Mineo, T.; Pareschi, G.; Rigato, V.; Spiga, D.; Tagliaferri, G. Background Rejection of Charged Particles in the Simbol-X Telescope: Preliminary Study of Protons Scattering.   SIMBOL-X: FOCUSING ON THE HARD X-RAY UNIVERSE: Proceedings of the 2nd International Simbol-X Symposium. AIP Conference Proceedings, Volume 1126, pp. 72-74 (2009)  

  11. U. L. Cicero, C. Arnone, M. Barbera, A. Collura, G. Lullo, E. Perinati e S. Varisco, «Planar technology for NDT-Ge X-ray microcalorimeters: absorber fabrication,» LTD13, AIP Conference Proceedings, vol. 1185, p. 112–114, 2009.

  12. Collura, A.; Barbera, M.; Varisco, S.; Basso, S.; Pareschi, G.; Tagliaferri, G.; Ayers, T. Simbol-X Mirror Module Thermal Shields: I-Design and X-Ray Transmission.   SIMBOL-X: FOCUSING ON THE HARD X-RAY UNIVERSE: Proceedings of the 2nd International Simbol-X Symposium. AIP Conference Proceedings, Volume 1126, pp. 44-47 (2009)

  13. Barbera, M.; Ayers, T.; Collura, A.; Nasillo, G.; Pareschi, G.; Tagliaferri, G. Simbol-X Mirror Module Thermal Shields: II-Small Angle X-Ray Scattering Measurements.   SIMBOL-X: FOCUSING ON THE HARD X-RAY UNIVERSE: Proceedings of the 2nd International Simbol-X Symposium. AIP Conference Proceedings, Volume 1126, pp. 48-51 (2009)  

  14. Perinati, E.; Barbera, M.; Varisco, S.; Silver, E.; Beeman, J.; Pigot, C. Experimental evidence of an incomplete thermalization of the energy in an x-ray microcalorimeter with a Ta/Au absorber.   Review of Scientific Instruments, Volume 79, Issue 5, pp. 053905-053905-4 (2008)

  15. Szymon, Gburek; Collura, Alfonso; Barbera, Marco; Reale, Fabio; Sylwester, Janusz; Kowalinski, Miroslaw; Bakala, Jaroslaw; Kordylewski, Zbigniew; Plocieniak, Stefan; Podgorski, Piotr; Trzebinski, Witold; Varisco, Salvatore Detailed Calibration of SphinX instrument at the Palermo XACT facility of INAF-OAPA.   37th COSPAR Scientific Assembly. Held 13-20 July 2008, in Montréal, Canada., p.3114 (2008)

  16. Perinati, E.; Mineo, T.; Cusumano, G.; Piro, L.; Pareschi, G.; Barbera, M. Designing an x-ray baffle for stray-light reduction at the focal plane of the Wide Field Imager on board EDGE.   Space Telescopes and Instrumentation 2008: Ultraviolet to Gamma Ray. Edited by Turner, Martin J. L.; Flanagan, Kathryn A. Proc. SPIE, Volume 7011, pp. 701139-701139-8 (2008)

  17. Barbera, Marco; Mineo, Teresa; Perinati, Emanuele; Schnopper, Herbert W.; Spiga, Daniele; Taibi, Angelo Spiral conical approximations to double reflection Wolter optics.   Space Telescopes and Instrumentation 2008: Ultraviolet to Gamma Ray. Edited by Turner, Martin J. L.; Flanagan, Kathryn A. Proc. SPIE, Volume 7011, pp. 701136-701136-7 (2008)

  18. U. L. Cicero, C. Arnone, M. Barbera, A. Collura, G. Lullo e S. Varisco, «Planar array technology for the fabrication of germanium X-ray microcalorimeters,» IEEE Nuclear Science Symposium Conference Record, p. 1789–1792, 2008.

  19. Perinati, E.; Barbera, M.; Beeman, J.; Collura, A.; Dumoulin, L.; Pigot, C.; Piro, L.; Silver, E.; Varisco, S. Test of x-ray microcalorimeters with bilayer absorbers.   High Energy, Optical, and Infrared Detectors for Astronomy III. Edited by Dorn, David A.; Holland, Andrew D. Proc. SPIE, Volume 7021, pp. 70211M-70211M-7 (2008)

  20. G. Chianetta, C. Arnone, M. Barbera, J. Beeman, A. Collura, G. Lullo, E. Perinati, E. Silver, "A fully planar approach to the construction of X-Ray microcalorimeters with doped Germanium sensors", 2008, Journal of Low Temperature Physics, Volume 151, Issue 1-2, pp. 387-393.

  21. L. Ferrari, F. Gatti, D. Pergolesi, M. Ribeiro Gomes, D. Bagliani, R. Valle, S. Dussoni, L. Piro, L. Colasanti, C. Macculi, M. Barbera, E. Perinati, "Study of microcalorimeters for astrophysics applications", 2008, Journal of Low Temperature Physics, Volume 151, Issue 1-2, pp. 271-276.

  22. M. Barbera, R. Candia, A. Collura, G. Di Cicca, S. Varisco, C. Zhang, H. Wang, J. Yang, W. Peng, X. Cui, X. Cao, X. Liang, "Calibration of the CHANG'E-1 x-ray fluorescence imaging spectrometer at INAF-OAPA", 2007a, Proc. SPIE, 6686, 15, 1-13.

  23. I. Sakurai, Y. Tawara, J.W. den Herder, M. Barbera, G. Cusumano, T. Mineo, E.G. Perinati, "Design and optimization of the wide-field spectrometer for EDGE mission", 2007, Proc. SPIE, 6688, 09, 1-8.

  24. A. Taibi, M. Barbera, G. Pareschi, H.W. Schnopper, G. Sironi, R. Valtolina. "Characterization of thin plastic foils for applications in x-ray optics technology", 2007, Proc. SPIE, 6688, 1B, 1-8.

  25. A. Collura, P. Attinà, M. Barbera, A. Ferri, G. Pareschi, E.G. Perinati, F.R. Powell, "Thermal shielding of the SIMBOL-X mirror assembly", 2007, Proc. SPIE, 6688, 0E, 1-5.

  26. V. Cotroneo, G. Pareschi, D. Spiga, M. Barbera, S.E. Romaine, R.J. Bruni, "Light material coatings for soft-x-ray reflectivity enhancement", 2007, Proc. SPIE, 6688, OU, 1-10.

  27. M. Barbera, T. Mineo, E. G. Perinati, A. Taibi, H. W. Schnopper, "Thin plastic foil X-ray optics with spiral geometry", 2007b, Proc. SPIE, 6688, 15, 1-13.

  28. L. Golub, E. Deluca, G. Austin, J. Bookbinder, D. Caldwell, P. Cheimets, J. Cirtain, M. Cosmo, P. Reid, A. Sette, M. Weber, T. Sakao, R. Kano, K. Shibasaki, H. Hara, S. Tsuneta, K. Kumagai, T. Tamura, M. Shimojo, J. McCracken, J. Carpenter, H. Haight, R. Siler, E. Wright, J. Tucker, H. Rutledge, M. Barbera, G. Peres, S. Varisco, "The X-Ray Telescope (XRT) for the Hinode Mission", 2007, Solar Physics, 243, 63-86.