J/MNRAS/493/3159 Modelling of wind and supernovae shocks (Gupta+, 2020) ================================================================================ Realistic modelling of wind and supernovae shocks in star clusters: addressing ^22^Ne/^20^Ne and other problems in Galactic cosmic rays. Gupta S., Nath B.B., Sharma P., Eichler D. =2020MNRAS.493.3159G (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Supernovae ; Supernova remnants ; Milky Way ; Positional data ; X-ray sources ; Radio sources Keywords: hydrodynamics - shock waves - methods:numerical - cosmic rays Abstract: Cosmic ray (CR) sources leave signatures in the isotopic abundances of CRs. Current models of Galactic CRs that consider supernovae (SNe) shocks as the main sites of particle acceleration cannot satisfactorily explain the higher ^22^Ne/^20^Ne ratio in CRs compared to the interstellar medium. Although stellar winds from massive stars have been invoked, their contribution relative to SNe ejecta has been taken as a free parameter. Here, we present a theoretical calculation of the relative contributions of wind termination shocks (WTSs) and SNe shocks in superbubbles, based on the hydrodynamics of winds in clusters, the standard stellar mass function, and stellar evolution theory. We find that the contribution of WTSs towards the total CR production is at least 25 per cent, which rises to >~50 per cent for young (~<10Myr) clusters, and explains the observed ^22^Ne/^20^Ne ratio. We argue that since the progenitors of apparently isolated supernovae remnants (SNRs) are born in massive star clusters, both WTS and SNe shocks can be integrated into a combined scenario of CRs being accelerated in massive clusters. This scenario is consistent with the observed ratio of SNRs to {gamma}-ray bright (L_{gamma}_>~10^35^erg/s) star clusters, as predicted by star cluster mass function. Moreover, WTSs can accelerate CRs to PeV energies, and solve other long-standing problems of the standard SN paradigm of CR acceleration. Description: Observations show that in Sbc galaxies (Milky-Way-type) the ratio of thermonuclear to core-collapse SNe is ~1/3 (Mannucci et al. 2005A&A...433..807M). Adding thermonuclear SNRs, this indicates a ratio of SNRs to WTS {gamma}-ray sources in our Galaxy of order 33-65. We can check this argument by counting the SNRs and {gamma}-ray bright clusters in a given volume. The size of the sampling volume is hard to decide, since {gamma}-ray bright clusters are rare: there are only three {gamma}-ray bright clusters near us, Cygnus at ~1.4kpc, Westerlund 1 at ~4kpc (Aharonian, Yang & de Ona Wilhelmi 2019NatAs...3..561A), and Westerlund 2 at ~5kpc (Yang et al. 2018A&A...611A..77Y). Therefore, it makes sense to use all these three and use a sphere of radius 5kpc around us. Counting the number of SNRs from the available catalogue, we find 124 of them within a distance of 5kpc (listed in Table C1). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file tablec1.dat 32 125 This table provides a list of SNRs which are located within 5kpc -------------------------------------------------------------------------------- See also: VII/272 : A catalogue of Galactic supernova remnants (Green, 2014) Byte-by-byte Description of file: tablec1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- ID [1/125] Internal SNR identifier 4 A1 --- m_ID [ab] Multiplicity flag (1) 6- 10 F5.1 deg GLON Galactic longitude 12- 17 F6.2 deg GLAT Galactic latitude 19- 20 A2 --- l_Dist [~< ] Limit flag on Dist 22- 30 A9 kpc Dist Distance 32 I1 --- Ref [1/2] Reference (2) -------------------------------------------------------------------------------- Note (1): In the original table two sources were labelled 120, we have added a multiplicity flag (a,b) to distinguish these two sources Note (2): Reference as follows: 1 = Green (2014BASI...42...47G, Cat. VII/272), https://www.mrao.cam.ac.uk/surveys/snrs/ 2 = https://hea-www.cfa.harvard.edu/ChandraSNR/snrcat_gal.html -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Ana Fiallos [CDS] 20-Apr-2023