ABSTRACT We report a detailed multi-wavelength study of the supernova remnant G296.5+10.0 using archival data from XMM–Newton and Fermi-LAT complemented with ATCA observations. In the X-ray band, we performed an adaptive smoothing on the double background subtracted images to construct an X-ray mosaic map with six individual observations. Below 2.0 keV, G296.5+10.0 is asymmetrical, with the south-east side of the radio shell brighter than the south-west one. The spatially resolved X-ray spectral study confirms the thermal origin of the plasma, with enhanced metal abundances, probably arising from ejecta material according to the H i and infrared ($140~{\mu \rm m}$) distributions. In the γ-ray band, we analysed 14 years of accumulated Fermi observations below 500 GeV via different fitting processes. To discuss the origin of the γ-ray emission, we compare the GeV results with H i structures probably associated with the SNR and with the radio spectral indices found at various positions towards the radio shell. Moreover, we identified diverse sources candidates to contribute γ-ray emissions observed. Also, we calculated the lepto-hadronic spectral energy distribution of the remnant for synchrotron, inverse Compton, Bremsstrahlung, and proton–proton processes. The emission at low energies can be explained by electron-synchrotron radiation, with a weak magnetic field of $B=25\, {\rm \mu G}$, while the γ-ray data can be explained by hadronic interactions. Employing the reddening-distance method, we computed a distance of 1.4 kpc for the SNR, implying an age of 14 000 yr.

ABSTRACT We present a detailed spatially resolved X-ray study of Chandra observations towards the central region of the supernova remnant (SNR) G359.1-0.5. We removed 168 point-like sources and performed an adaptive smoothing on the entire field-of-view of the Chandra ACIS-I observation. The images obtained show an extended X-ray emission below $4.0\, {\rm keV}$ that partially fills the interior of G359.1-0.5. In order to characterize the X-ray emission, we divide the emitting area into 10 different regions inside the remnant. We identify the presence of at least four emission lines that confirm the thin thermal plasma origin. All spectral regions are well fitted by a recombining plasma model (VRNEI) with an absorbing column density range from 1.5 to $2.1\times 10^{22}\, {\rm cm}^{-2}$, and electron temperatures from 0.14 to $0.19\, {\rm keV}$. We also calculated an average electron density of $0.7\, {\rm cm}^{-3}$, estimated an age of 2.8 × 104 yr for the remnant, which can be lower if the filling factor is considered, and an X-ray luminosity of $1.6 \times 10^{35} \, {\rm erg}\, {\rm s}^{-1}$. Finally, we show that the X-ray emission is morphologically anti-correlated with adjacent CO clouds interacting with the SNR. Our results favour that the recombining plasma inside G359.1-0.5 could be explained via adiabatic cooling.

Fil: Eppens, Laura Karina. Provincia de Buenos Aires. Gobernacion. Comision de Investigaciones Cientificas. Instituto Argentino de Radioastronomia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto Argentino de Radioastronomia; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomia y Fisica del Espacio; Argentina

ABSTRACT We report new CO observations and a detailed molecular-line study of the mixed morphology supernova remnant G359.1−0.5, which contains six OH (1720 MHz) masers along the radio shell, indicative of shock-cloud interaction. Observations of 12CO and 13CO J:1–0 lines were performed in a ∼38 × 38 arcmin area with the on-the-fly technique using the Kit Peak 12 Meter telescope. The molecular study has revealed the existence of a few clumps with densities ∼103 cm−3 compatible in velocity and position with the OH (1720 MHz) masers. These clumps, in turn, appear to be part of a larger, elongated molecular structure ∼34 arcmin long extending between −12.48 and +1.83 km s−1, adjacent to the western edge of the radio shell. According to the densities and relative position with respect to the masers, we conclude that the CO clouds depict unshocked gas, as observed in other remnants with OH (1720 MHz) masers. In addition, we investigated the distribution of the molecular gas towards the adjacent γ-ray source HESS J1745-303 (Aharonian et al. 2006) but could not find any morphological correlation between the γ-rays and the CO emission at any velocity in this region.