Damping of Alfvén waves in partially a ionized medium and the cosmic grammage in the proximity of supernova remnants

Discussion timeslot (ZOOM-Meeting): 15. July 2021 - 12:00
ZOOM-Meeting URL: https://desy.zoom.us/j/91896950007
ZOOM-Meeting ID: 91896950007
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/14-CRs-and-ISM-CRD/45
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-06/7

Abstract:
'We investigate the damping of Alfvén waves generated by therncosmic ray resonant streaming instability as due to ion-neutralrndamping, turbulent damping and non linear Landau damping, in thernwarm ionised and warm neutral phases of the interstellar medium.rnWe do so in the context of the cosmic ray escape and propagationrnin the proximity of supernova remnants. For the ion-neutral damping,rnstate-of-the-art damping coefficients are used, where the momentumrntransfer and charge exchange cross sections between various speciesrnof ions and neutrals are computed in detail or measured. Werninvestigate whether the self-confinement of cosmic rays nearbyrnsources can appreciably affect the grammage. In fact, if this isrnthe case, the standard picture, in which CR secondaries are producedrnduring the whole time spent by cosmic rays throughout the Galacticrndisk, should be deeply revisited. We show that the ion-neutralrndamping and the turbulent damping effectively limit the residencerntime of cosmic rays in the source proximity, so that the grammagernaccumulated near sources is found to be negligible. This alsornhappens in the most optimistic scenario where ion-neutral dampingrnis less effective, namely in a medium with only neutral heliumrnand fully ionized hydrogen, contrary to what was previously suggested.'

Authors: Sarah Recchia | Daniele Galli | Lara Nava | Marco Padovani | Stefano Gabici | Alexandre Marcowith | Vladimir Ptuskin | Giovanni Morlino
Indico-ID: 948
Proceeding URL: https://pos.sissa.it/395/167