Ellis R Owen

Astrophysicist

Hi! I am Ellis Owen, a post-doctoral research fellow at the Institute of Astronomy, National Tsing Hua University, in Hsinchu, Taiwan. You can find out about my background, research interests, recent work and new results on this site.

Contact: erowen@gapp.nthu.edu.tw

NCTS/NTHU Taiwan Winter school participants can access archived resources using the link below. Note: log-in required, using the access details emailed to all participants.

Cosmic rays in galaxies

Vibrantly star-forming galaxies are rich in energetic cosmic rays. These are accelerated by diffusive shock acceleration processes in supernova remnants. The cosmic rays interact to release energy into their environment, and can be contained by the magnetic fields of their host galaxy. Being refocused into the interstellar medium of galaxies and able to penetrate deep into the shielded birthplaces of stars, cosmic rays are an important agent in regulating feedback processes within galaxies. [Find out more here]

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Image Credit: ESA/Herschel/SPIRE/PACS/Gould Belt Survey/D. Arzoumanian (CEA Saclay) 

Stephan's Quintet, a compact group of galaxies experiencing forced interactions and successive bursts of star-formation. Composite image with JWST NIRCam-MIRI. Image credit: NASA, ESA, CSA, STScI, 2022, used in accordance with STScI/NASA content use policy.

High energy processes and phenomena around galaxies

Cosmic rays modify the physical and dynamical properties of circum-galactic and intergalactic media,  and drive the emission from large bubbles emanating from Milky Way like galaxies. They can also have an important role in regulating the evolution and material inter-flows between interacting galaxies, like those tightly knit together in compact groups. The presence and impacts of cosmic rays around galaxies can be probed in a number of ways, from assessing the X-ray `color’ of distant galactic outflows, to the gamma-ray and radio emission from galaxy bubbles. [Find out more here]

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The origins and characteristics of energetic backgrounds

High energy backgrounds of photons and ultra high-energy cosmic ray nuclei have their origins in distant source populations. From spatial statistics in high energy backgrounds and/or their nuclear composition, crucial information can be uncovered about the underlying astrophysical sources. [Find out more here]

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Image Credit: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray)