Journal
NATURE ASTRONOMY
Volume 4, Issue 2, Pages 167-173Publisher
NATURE RESEARCH
DOI: 10.1038/s41550-019-0910-0
Keywords
-
Categories
Funding
- German Ministry for Education and Research (BMBF)
- Max Planck Society
- German Research Foundation (DFG)
- Helmholtz Association
- Alexander von Humboldt Foundation
- French Ministry of Higher Education, Research and Innovation [CNRS/IN2P3]
- (CNRS/INSU)
- Commissariat a l'energie atomique et aux energies alternatives (CEA)
- UK Science and Technology Facilities Council (STFC)
- Knut and Alice Wallenberg Foundation
- National Science Centre, Poland [2016/22/M/ST9/00382]
- National Research Foundation
- University of Namibia
- National Commission on Research, Science and Technology of Namibia (NCRST)
- Austrian Federal Ministry of Education, Science and Research
- Austrian Science Fund (FWF)
- Australian Research Council (ARC)
- EGI Federation - EU FP7 Marie Curie [PIEF-GA-2012-332350]
Ask authors/readers for more resources
An angular extension at gamma-ray energies of 52 arcseconds is detected for the Crab nebula, revealing the emission region of the highest-energy gamma rays; simulations of the electromagnetic emission provide a non-trivial test of our understanding of particle acceleration in the Crab nebula. The Crab nebula is one of the most-studied cosmic particle accelerators, shining brightly across the entire electromagnetic spectrum up to very-high-energy gamma rays(1,2). It is known from observations in the radio to gamma-ray part of the spectrum that the nebula is powered by a pulsar, which converts most of its rotational energy losses into a highly relativistic outflow. This outflow powers a pulsar wind nebula, a region of up to ten light-years across, filled with relativistic electrons and positrons. These particles emit synchrotron photons in the ambient magnetic field and produce very-high-energy gamma rays by Compton up-scattering of ambient low-energy photons. Although the synchrotron morphology of the nebula is well established, it has not been known from which region the very-high-energy gamma rays are emitted(3-8). Here we report that the Crab nebula has an angular extension at gamma-ray energies of 52 arcseconds (assuming a Gaussian source width), much larger than at X-ray energies. This result closes a gap in the multi-wavelength coverage of the nebula, revealing the emission region of the highest-energy gamma rays. These gamma rays enable us to probe a previously inaccessible electron and positron energy range. We find that simulations of the electromagnetic emission reproduce our measurement, providing a non-trivial test of our understanding of particle acceleration in the Crab nebula.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available