Core-collapse supernovae as cosmic ray sources

Abstract

Core collapse supernovae (CCSNe) produce fast shocks which pervade the dense circum-stellar medium (CSM) of the stellar progenitor. Cosmic rays (CRs) if accelerated at these shocks can induce the growth of electromagnetic fluctuations in the foreshock medium. In this study, using a self-similar description of the shock evolution, we calculate the growth timescales of CR-driven instabilities. We select a sample of nearby core collapse radio supernova of type II and Ib/Ic. From radio data we infer the parameters which enter in the calculation of the instability growth times. We find that extended IIb SNe shocks can trigger fast intra day instabilities, strong magnetic field amplification and CR acceleration. In particular, the non-resonant streaming instability can contribute to about 50% of the magnetic field intensity deduced from radio data. This results in the acceleration of CRs in the range 1-10 PeV within a few days after the shock breakout. In order to produce strong magnetic field amplification and CR acceleration a fast shocks pervading a dense CSM is necessary. In that aspect IIn supernovae are also good candidates. But a detailed modeling of the blast wave dynamics coupled with particle acceleration is mandatory for this class of object before providing any firm conclusions. Finally, we find that the trans-relativistic object SN 2009bb even if it produces more modest magnetic field amplification can accelerate CRs up to 2-3 PeV within 20 days after the outburst.

Upper limits on very-high-energy gamma-ray emission from core-collapse supernovae observed with H.E.S.S.

“…This equation shows that in order to reach energies of 100 TeV, typically an acceleration time shorter than a day is sufficient, and for reaching the CR knee at 3 × 10 15 eV, an acceleration time of days to weeks is needed provided that the magnetic fields are > 1 G, instead of the 10 − 100 µG measured in young SNRs. More detailed calculations that also take into account the expected evolution of the magnetic field strength and escape of the highest energy particles confirm these time scales, see Tatischeff (2009);Marcowith et al (2018). Core-collapse (cc-)SNe originating from stellar progenitors with dense winds can fulfil the right conditions for CR acceleration, provided that the shocks are collisionless (Katz et al 2011;Murase et al 2011;Bell et al 2013).…”

“…This equation is valid as long as the maximum photon energy E ph,max (related to the maximum energy of accelerated particles E max ) is significantly higher than E 0 . As shown by Marcowith et al (2018), in the case of cc SNe evolving in their dense wind progenitor such as SN 1993J, E max conservatively remains above ∼0.5 PeV (i.e. E ph,max 30 TeV) during the first year after the SN, so that equation 1 can be used as is.…”

“…Moreover, it has been suggested that, for supernova remnants evolving in the winds of their progenitors, the maximum CR energy is reached in the early phase of the SNR development, within days to months after the SN event and not at the time the SNR is several hundred to thousand years old (e.g. Voelk & Biermann 1988;Cardillo et al 2015;Marcowith et al 2018). The highest energy CR hadrons are then possibly accelerated in this early phase, at least for a subset of SNe (Bell et al 2013;Zirakashvili & Ptuskin 2016).…”

“…One prime example is the young type IIb SN 1993J, for which a strong magnetic field, 1-100 G, and shock speeds as high as 20,000 km s −1 have been estimated by Fransson & Björnsson (1998) and Tatischeff (2009). Given these estimates and time scales for acceleration to PeV energies, there are good reasons to think that SN 1993J-like SNe can accelerate CR hadrons up to PeV energies within days to a few weeks (see Marcowith et al 2018, and references therein). However, gamma-ray emission from SNe has not been detected so far, and upper-limits in the GeV domain have been established for type IIn SNe (Ackermann et al 2015), and superluminous SN candidates (Renault-Tinacci et al 2018).…”

Supernova X-Ray Database (SNaX) Updated to Ensure Long-term Stability

“…Supernovae (SNe) are fascinating objects that are observed over the entire wavelength range, from radio (Weiler et al 2002) to X-rays (Dwarkadas & Gruszko 2012), with even a couple of unconfirmed sources in the Fermi γ-ray waveband (Yuan et al 2018;Xi et al 2020). They are also expected to be a source of high energy cosmic-rays (Marcowith et al 2018). Large-scale optical surveys routinely discover hundreds of SNe each year.…”