Hello! I'm Yossef Zenati

 

I am a postdoctoral fellow at Johns Hopkins University in Baltimore, Maryland, U.S.A.
I received my Ph.D. from the Technion Institute in Haifa, Israel under the supervision of Prof. Hagai Perets.

My interests cover a broad range of topics including mergers of compact objects, transient events, nuclear astrophysics, and MHD turbulence. Much of my research focuses on fundamental aspects of thermonuclear supernovae, compact binary mergers, and fluid mechanics, and turbulence, with both numerical and analytical modeling.

I use hydrodynamic simulations on supercomputers to study including microphysics, interactions, and nuclear reactions of nuclear burning, neutrino emissivities, turbulence, and compact object mergers.

 

In my free time, I enjoy climbing mountains and urban walls, and also running.
Science is one of my passions, especially mathematics.

Yossef Zenati

PHYSICIST, Postdoctoral JHU Fellow

 

      Phone:                            Email:

    +14432481924                     oyossefzm@gmail.com

                                           yzenati1@jhu.edu 

           

                         

                          Address:

526 w university Pkwy, apt103, Baltimore, MD21210, USA

or 

PO Box: 311, Abu-Snan village 24905000, North Israel, Israel

EDUCATION
 
2016-2019

PhD., Physics

Technion - Israel Institute of Technology

 

Mechanisms for thermonuclear stellar explosions and the origin of type Ia supernovae

 

Advisor: Hagai B. Perets

2010-2012 

MSc Physics, honors cum laude

TAU - Tel-Aviv University- Faculty of Exact Sciences

The Ejection Binary Stars In Parabolic Orbits By Massive Black Hole

 

Advisors: Shay Zucker and Amiel Sternberg

2004-2007

BSc

Technion - Israel Institute of Technology

BSc Physics and Geo-information engineering

AWARDS

  • The Council for Higher Education (CHE) scholarship                                                                                    2020-2021

  • Council for Higher Education - Technion’s Graduate Student Research                                                     2017-2019     

  • Irwin and Joan Jacobs Excellence Fellowship for outstanding graduate students: Yuhubd and Cohen 2017 

  • Technion’s Graduate Student Research Grant                                                                                               2016

  • Tel-Aviv University- Faculty of Exact Sciences - summa cum laude                                                             2011

  • Technion’s Undergraduate Dean’s list                                                                                                            2007

 
MY RESEARCH

I work on binary systems made of Neutron Stars (NS) and NS/ White Dwarfs 
(WD)/Black Holes (BH), as well as double White Dwarf systems, and core-collapse of massive, rapidly rotating stars.
Currently, I'm studying magnetic helicity which is robustly conserved in systems with large magnetic Reynolds numbers, including most systems of astrophysical interest. This plays a major role in suppressing the kinematic large scale dynamo and driving the large scale dynamo through the magnetic helicity flux. 

Also, I study how compact objects form, evolve, and merge, and which transient events they produce. I also work on resolving the critical conditions for deflagration and detonation shock waves.
I study turbulent nuclear burning, which can largely enhance nuclear burning rates and may serve as an additional mechanism for stellar explosions. Moreover, it may power thermonuclear and pair-instability supernovae, liberate the neutrinos in core-collapse supernovae, and synthesize r-process heavy nuclei in kilonovae and collapsars.

Hypotheses are tested using extensive hydrodynamical, thermonuclear, AMR, and multidimensional simulations coupled with detailed nuclear reaction networks (The computational requirements for these use MESA and FLASH). The results of these simulations are followed by an analysis of composition using a large-scale nucleosynthetic network – (PPN). These enable us just to calculate the detailed properties of SN’s ejecta. The results of post-processing are also used as an input for modeling the radiative transfer evolution (SuperNu), which is used to provide detailed (light curve/spectra) predictions for the observable properties arising from each theoretical model and chemical composition of SN ejecta.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CO WD 0.8M⊙ & HeCO WD 0.69M⊙: Propagation of the shock originating from the helium detonation as it moves around the primary WD. The panels show the time evolution from the time of the ignition of the helium detonation (top left panel) to the time when the shock converges in the CO core of the primary WD (bottom right panel). The black dotted and gray solid contours indicate densities of 2×10^6 g cm−3 and 10^7 g cm−3 ,  respectively.


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Z_R Snapshots of Collapsar (M~13 M⊙) show density, temperature, and He4 as well as Ni56 mass fractions in the meridional plane ( ̄ρ,z) during the first.1.7 viscous timescales. Production of He4 and Ni56  indicate significant nuclear burning that develops into a global detonation of the accretion disk and leads to the production of iron-group nuclei.  

  

 

 

 

 

Log-log plot of the dimensionless fractional turbulent enhancement in the nuclear burning rate, as a function of the RMS temperature fluctuation on length scale r, normalized to the mean temperature, in the distributed burning regime. The curves shown are for neutrino cooling via the URCA process (solid line), C12 -C12 burning (dashed), and triple-alpha reaction (dot dashed). The inset figure shows the same three curves on the same set of axes, compensated by the factor (1/[n*(n - 1)]). For weak enhancement, the compensated enhancement collapses onto a single curve, demonstrating its universal nature.

 

 

 

 

 
PUBLICATIONS
  • My publications can be found through NASA's ADS (link).

  • Another database is Google Scholar, although not that updated (link).

     

  • Recent Collaborations :
     

    • Dr. Alexey Bobrick, Lund University, Sweden.  Topic: SN Ia & NS-WD mergers- theory & simulation.

    • Prof. Anna Frishman, Technion Institute, Israel.  Topic: 2D turbulencetheory & simulation.

    • Prof. Armin Rest, STScI, USA.  Topic: SNIa, Ib/c & IIb- theory & observation.

    • Prof. Brian Metzger, Columbia University, USA.  Topic: Collapsar & NS-WD mergers- theory & simulation.

    • Ass. Faculty Daniel Siegal, Perimeter Institute, Ontario, Canada.  Topic: Collapsar- theory & simulation.

    • Prof. Ethan Vishniac, Johns Hopkins University, USA.  Topic: MHD turbulencetheory & simulation.

    • Prof. Hagai Perets, Technion Institute, Israel.  Topic: SN Ia & SE of WDtheory & simulation.

    • Prof. Julian Krolik, Johns Hopkins University, USA. Topic: NS-NS mergers & Neutrino fluxtheory & simulation

    • Prof. Raffaella Margutti, Northwestern University, USA.  Topic: SN Iatheory & observation.

    • Prof. Robert Fisher, University of Massachusetts Dartmouth, USA.  Topic: SN Ia & turbulencetheory & simulation.

    • Ass. Faculty Ruediger Pakmor, Max Planck InstituteDeutschland.  Topic: SN Iatheory & simulation.

    • Ass. Faculty Silvia Toonen, University of Amsterdam, Netherlands.  Topic: SN Ia & SE of WDtheory & simulation.

    •  

 

 
CONFERENCES & SEMINARS

• Seminar, STScl Institute, Baltimore, USA, March 2021

• Seminar, CENTRA Institute, Lisbon, Portugal, March 2021

Seminar, Nordita Institute, Stockholm, Sweden, Dec 2020

Seminar, Johns Hopkins University (JHU), Baltimore, USA, Nov 2020

Seminar, Technion (IIT), Haifa, Israel, Jun 2020

• Seminar, Tel-Aviv University (TAU), Tel-Aviv, Israel, Dec 2019

White Dwarfs and SN Ia (IAU Symposium 357), Hawaii, USA, Oct 2019

• Compact White Dwarf Binaries (CWDB 2019), Yerevan, Armenia, Sep 2019

• Progenitors of Type Ia Supernovae, Lijiang, China, Aug 2019

• The Beginnings and Ends of Double White Dwarfs, Copenhagen, Denmark, Jul 2019

• Technion Physics Graduate project, Haifa, Israel, Jun 2019

• Seminar, University of Maryland, Washington DC, USA, April 2019

• Seminar, Columbia University, New York, USA, Feb 2019

• Seminar, Brown University, Boston, USA, Feb 2019

• Seminar, University of Massachusetts Dartmouth, Boston, USA, June 2019

• Lunch talk, Columbia University, New York, USA, July 2018

• TAPIR Special Seminar, Caltech, Pasadena CA, USA, July 2018

• Observational Signatures of SN Ia, Leiden, the Netherlands, Feb 2018

• Astronomy Israel day, Jerusalem, Israel, Jan 2018

• The Physics of Extreme - Gravity Stars, Nordita Institute, Stockholm, Sweden, Jun 2017

• Lunch talk, Columbia University, New York, USA, Aug 2016

 
Moments And Places