The Crab Nebula at sub-arcsecond resolution with the International LOFAR Telescope

Vol. 699
6. Interstellar and circumstellar matter

The Crab Nebula at sub-arcsecond resolution with the International LOFAR Telescope

The Crab Nebula, number one in the Messier catalog of fuzzies, is the paradigmatic supernova remnant. It has everything: a central neutron star powering a pulsar wind, a highly structured thermal remnant with the nucleosynthetic signatures of the explosion, and a known birthdate. And it remains a treasure trove of phenomena for radio interferometric studies. The authors present the highest-resolution LOFAR maps to date (with resolutions better than an arcsecond), which, combined with higher-frequency maps, provide a clean separation of the thermal and synchrotron components. A remarkable feature of these new maps is the identification of an ensemble of thermal filaments for which electron densities are derived from bremsstrahlung absorption. These should form ideal targets for infrared and far-infrared high-resolution spectroscopic studies. The resulting maps and analyses are essential benchmarks for any theoretical modeling of the early evolution of plerion supernova remnants and their interaction with the circumstellar and interstellar environments.