Using interstellar clouds to search for Galactic PeVatrons: Gamma-ray signatures from supernova remnants

Mitchell AMW, Rowell GP, Celli S, Einecke S (2021)

Publication Type: Journal article, Original article

Publication year: 2021

Journal

Monthly Notices of the Royal Astronomical Society Oxford University Press

Book Volume: 503

Pages Range: 3522-3539

Journal Issue: 3

DOI: 10.1093/mnras/stab667

Abstract

Interstellar clouds can act as target material for hadronic cosmic rays; gamma rays subsequently produced through inelastic proton–proton collisions and spatially associated with such clouds can provide a key indicator of efficient particle acceleration. However, even in the case that particle acceleration proceeds up to PeV energies, the system of accelerator and nearby target material must fulfil a specific set of conditions in order to produce a detectable gamma-ray flux. In this study, we rigorously characterize the necessary properties of both cloud and accelerator. By using available supernova remnant (SNR) and interstellar cloud catalogues, we produce a ranked shortlist of the most promising target systems, those for which a detectable gamma-ray flux is predicted, in the case that particles are accelerated to PeV energies in a nearby SNR. We discuss detection prospects for future facilities including CTA, LHAASO and SWGO; and compare our predictions with known gamma-ray sources. The four interstellar clouds with the brightest predicted fluxes >100 TeV identified by this model are located at (l,b) = (330.05, 0.13), (15.82, −0.46), (271.09, −1.26), and (21.97, −0.29). These clouds are consistently bright under a range of model scenarios, including variation in the diffusion coefficient and particle spectrum. On average, a detectable gamma-ray flux is more likely for more massive clouds; systems with lower separation distance between the SNR and cloud; and for slightly older SNRs.

Authors with CRIS profile

Alison Mitchell

Involved external institutions

Università degli studi "La Sapienza" IT Italy (IT) University of Adelaide AU Australia (AU) University of Zurich / Universität Zürich (UZH) CH Switzerland (CH)

How to cite

APA:

Mitchell, A.M.W., Rowell, G.P., Celli, S., & Einecke, S. (2021). Using interstellar clouds to search for Galactic PeVatrons: Gamma-ray signatures from supernova remnants. Monthly Notices of the Royal Astronomical Society, 503(3), 3522-3539. https://doi.org/10.1093/mnras/stab667

MLA:

Mitchell, Alison M. W., et al. "Using interstellar clouds to search for Galactic PeVatrons: Gamma-ray signatures from supernova remnants." Monthly Notices of the Royal Astronomical Society 503.3 (2021): 3522-3539.

BibTeX: Download