Samar Safi-Harb, PhD
Professor of Physics & Astronomy
Welcome to my homepage!
I am a high-energy astrophysicist researching the aftermath of supernova explosions of stars and the formation of some of the most exotic and magnetic stars in the Universe.
The astrophysical objects that fascinate me include supernova remnants (SNRs), pulsar wind nebulae (PWNe), neutron stars, magnetars, microquasars and their interaction with the Interstellar Medium.
My team's research probes the physics of the extreme (extreme temperatures, gravity and magnetism) unattainable on Earth! Our research also tackles the origin of the heavy elements essential for Life, and the sites for particle acceleration to ultra-high energies (cosmic PeVatrons).
NASA's Chandra X-ray Images: a zoo of neutron stars and Pulsar Wind Nebulae
Left: 3D simulations of an SNR on a supercomputer.
Credit: G. Ferrand (Ferrand, Decourchelle & Safi-Harb 2014)
A cartoon of the Galactic Microquasar SS 433
My research program involves the study of supernova remnants and compact objects with focus on high-energy satellite data such as NASA's Chandra X-ray Observatory and NuSTAR, and ESA’s XMM-Newton satellite. Our research is complemented with studies at other wavelengths, and with modelling and numerical simulations. A primary focus of our research is to study the diversity (or zoo) of SNRs and neutron stars to probe their physics, magnetic field evolution, supernova progenitors, and unveil the way these objects transfer their energy to, and interact with, the Interstellar Medium (ISM). One particular area of interest is the study of Pulsar Wind Nebulae, the "clouds" of particles and radiation powered by fast- and not-so-fast spinning neutron stars.
Supernova remnants are also believed to be major accelerators of cosmic rays to very high energies (~1000 TeV=1 PeV or the so-called “knee” of the cosmic ray spectrum; thus the name PeVatrons). Our research also involves addressing the physics of particle acceleration at supernova shocks and investigating the maximum energies to which cosmic rays are accelerated in supernova remnants, using modelling and state-of-the-art numerical 3D simulations.
We collaborate with astrophysicists across continents and make use of telescopes spanning the electromagnetic spectrum (from radio to gamma-rays). Motivated by the 2017 LIGO ground-breaking discovery of gravitational waves from a neutron star merger, we are also expanding our research into Multi-Messenger Astrophysics.
I have served as a science working group member on the ASTRO-H (Hitomi) X-ray mission (2011-2018). I am an associate member of H.E.S.S., a member of the upcoming Cherenkov Telescope Array (CTA), and participate in scientific activities of the future ESA-led ATHENA X-ray mission, proposed US-led Lynx and AXIS X-ray missions and Canada-led CASTOR UV-optical mission. In the radio regime, I collaborate with the UofM VLASS team as part of CIRADA and have recently joined the Murchison Widefield Array (MWA). I currently lead the neutron stars group for Colibri, Canada's flagship X-ray mission proposed for the 2030's.
Check out this Article highlighting some of our research on neutron stars and supernova remnants.