Ehud Behar

Behar, Ehud   Faculty
Topic:   Astrophysics
Office:Lidow Complex Room:613 Phone:04-829-5561 
Research Interests & Publications:  

Fields of research:

High Energy Astrophysics

My group and I use the most modern instruments in space and on the ground as well as theoretical models to research high-energy astrophysical phenomena.

We research targets such as black holes, coronally active stars, galactic and stellar winds, and gamma ray bursts, as well as the elusive intergalactic medium.

My main interests are to detect and characterize plasma under extreme conditions, e.g., just before it falls into a black hole, when it is launched to sub-luminal speeds, or when it is shock heated to millions of degrees.

Fundamental questions we are interested in are: What is the electromagnetic signal of gas near a black hole? How can we detect the intergalactic medium, where most of the baryons of the Universe are? What are the physical mechanisms behind stellar and black-hole coronae and mass ejection?

We also have an ongoing program to build gamma-ray detectors for a NASA mission to space.

Research Interests:
Observational Astrophysics: Observations of super-massive black holes, active stars, stellar winds, and supernova remnants
Experimental Astrophysics: Gamma ray detectors for space
Laboratory Astrophysics: Experiments in support of astrophysics, the study of highly charged atoms in ion traps and plasma sources

Director of Asher Space Research Institute
and involved through ASRI investigators in projects of Advanced Optics, Electric Propulsion, Very Low Earth Orbits, Earth Remote Sensing

Selected publications:

  • L. Yacobi, D. Guetta, and E. Behar, Constraints on The Hadronic Content of Gamma Ray Bursts. The Astrophysical Journal, 793, 48 (2014).

  • J. Kaastra et al., A fast and long-lived outflow from the supermassive black hole in NGC 5548, Science, 345, 64 (2014).

  • H. Edri, S. E. Rafter, S. Kaspi, D. Chelouche, and E. Behar, Photometric Reverberation Mapping of NGC 4395, The Astrophysical Journal, 756, 73 -80, (2012).

  • E. Behar, S. Dado, A. Dar, and A. Laor, Can X-Ray Absorption of High-Redshift Sources Probe The Missing Baryons? The Astrophysical Journal, 734, 26-34, (2011).

  • M.C. Simon et al.,Resonant and Near-Threshold Photoionization of Fe14+. Physical Review Letters, 105, id183001 (2010).

  • E. Behar, Density Profiles in Seyfert Outflows. The Astrophysical Journal, 703, 1346 - 1351 (2009).

  • R. Nordon and E. Behar, Abundance variations and first ionization potential trends during large stellar flares. Astronomy & Astrophysics, 482, 639 - 651 (2008).

  • T. Holczer, E. Behar, and S. Kaspi. Absorption Measure Distribution of the Outflow in IRAS 13349+2438: Direct Observation of Thermal Instability? The Astrophysical Journal, 663, 799-807 (2007).

  • E. Behar, V.L. Jacobs, J. Oreg, A. Bar-Shalom, and S.L. Haan. Effects of Quantum Interference between Radiative and Dielectronic Recombination for the He-Like Ions Ar16+ and Fe24+. Phys. Rev. A, 69, 022704 (1-8) (2004).

  • E. Behar, A.P Rasmussen, A.J. Blustin, M. Sako, S.M. Kahn, J.S. Kaastra, G.Branduardi- Raymont, and K.C. Steenbrugge. A long look at NGC 3783 with the XMM-Newton Reflection Grating Spectrometers. The Astrophysical Journal, 598, 232 - 241 (2003).

  • E. Behar, M. Sako, and S.M. Kahn. Soft x-ray absorption by Fe0+ to Fe15+ in active galactic nuclei. The Astrophysical Journal 563, 497-504 (2001).

  • A.C. Brinkman, E. Behar, M. Güdel, et al. First light measurements with the XMM-Newton Reflection Grating Spectrometers: Evidence for an inverse First Ionization Potential effect and anomalous Ne Abundance in the coronae of HR 1099. Astronomy & Astrophysics 365, L324-L328 (2001).

  • E. Behar, P. Mandelbaum, J.L. Schwob, A. Bar-Shalom, J. Oreg, and W.H. Goldstein. Dielectronic recombination rate coefficients for highly ionized Ni- like atoms. Phys. Rev. A 54, 3070-3077 (1996).