Broadband radio study of the supernova remnant Kes 73

Abstract

Strong shocks occurring in supernova remnants (SNRs), and their interaction with an often anisotropic surrounding medium, make SNRs ideal laboratories for studying the production and acceleration of cosmic rays (CRs). Due to their complex morphology and phenomenology, different CR populations are expected to exist throughout the remnants, each characterized by its own energy spectrum. A comprehensive understanding of particle acceleration mechanisms and energetics in SNRs requires spatially resolved spectral and morphological studies. We want to highlight the crucial role of high-resolution radio images at high frequencies (> 10 GHz) for studying the spectral properties of different remnant regions and better constraining the models that describe their non-thermal emission from radio to $\gamma$-ray wavelengths. We studied the integrated radio spectrum of the SNR Kes 73 using single-dish observations performed with the Sardinia Radio Telescope (SRT) between 6.9 and 24.8 GHz, complemented by published data. The high-resolution map at 24.8 GHz was used to search for spatial variations in the spectral index across the remnant. We present the SRT images of Kes 73, providing the highest-frequency morphological and spectral characterization ever obtained for this source. By combining our 18.7 and 24.8 GHz maps with previously published interferometric images at 1.4 and 5 GHz, we identify a flatter spectrum in the western bright region compared to the rest of the shell. In the same region, we detect overlapping ${}^{1}2$CO molecular emission and $\gamma$-ray radiation, providing strong evidence of SNR-molecular cloud interaction and enhanced CR production. We modelled the non-thermal radio to $\gamma$-ray emission from this region, favouring a lepto-hadronic scenario with a maximum electron energy of 1.1 TeV and a magnetic field strength of 25 $\mu$G.

arXiv comment11 pages, 9 figures, 3 tables

References in corpus (38)

• Trigonometric Parallaxes of High Mass Star Forming Regions: the Structure and Kinematics of the Milky Way
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• The WISE Catalog of Galactic HII Regions
• An Accurate Flux Density Scale from 50 MHz to 50 GHz
• GLEAM: The GaLactic and Extragalactic All-sky MWA survey
• A revised catalogue of 294 Galactic supernova remnants
• HESS VHE Gamma-Ray Sources Without Identified Counterparts
• FOREST Unbiased Galactic plane Imaging survey with the Nobeyama 45-m telescope (FUGIN) I: Project Overview and Initial Results
• Radio emission from Supernova Remnants
• Kinematic Distances: A Monte Carlo Method
• Sardinia Radio Telescope: General Description, Technical Commissioning and First Light
• Galactic Supernova Remnant Candidates Discovered by THOR
• The Sardinia Radio Telescope: From a Technological Project to a Radio Observatory
• The Distance and Age of the SNR Kes 73 and AXP 1E 1841-045
• The Evolution of NGC 7027 at Radio Frequencies: A New Determination of the Distance and Core Mass
• A Systematic Survey for Broadened CO Emission Toward Galactic Supernova Remnants
• Revised Distances to 21 Supernova Remnants
• New Distances to Four Supernova Remnants
• Evolutionary Models for 43 Galactic Supernova Remnants with Distances and X-ray Spectra
• On the radio spectra of supernova remnants
• Chandra and XMM-Newton imaging and spectroscopic study of the supernova remnant Kes 73 hosting the magnetar 1E 1841-045
• Revisiting the dust destruction efficiency of supernovae
• Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope at 1.5 GHz and 7 GHz
• Spatially resolved X-ray study of supernova remnants that host magnetars: Implication of their fossil field origin
• Emission Measures and Emission-measure-weighted Temperatures of Shocked ISM and Ejecta in Supernova Remnants
• Near-infrared [Fe II] and H${}_2$ Emission-line Study of Galactic Supernova Remnants in the First Quadrant
• Expansion of Kes 73, a Shell Supernova Remnant Containing a Magnetar
• High-resolution Near-infrared Spectroscopic Study of Galactic Supernova Remnants. I. Kinematic Distances
• Investigating the high-frequency spectral features of SNRs Tycho, W44 and IC443 with the Sardinia Radio Telescope
• Thermal radio absorption as a tracer of the interaction of SNRs with their environments
• New high-frequency radio observations of the Cygnus Loop supernova remnant with the Italian radio telescopes
• Study of the extended radio emission of two supernova remnants and four planetary nebulae associated to MIPSGAL bubbles
• Star formation activity in the neighbourhood of W-R 1503-160L star in the mid-infrared bubble N46
• A Study of Fermi-LAT GeV gamma-ray Emission towards the Magnetar-harboring Supernova Remnant Kesteven 73 and Its Molecular Environment
• Studying the nature of the unidentified gamma-ray source HESS J1841-055 with the MAGIC telescopes
• Methods for detection and analysis of weak radio sources with single-dish radio telescopes
• The SARAO MeerKAT Galactic Plane Survey extended source catalogue
• Large-field CO (J=1-0) observations toward SNR G150.3+4.5