We present here the results of the observation of CTB 37A obtained with the Xray Imaging Spectrometer onboard the Suzaku satellite. The X-ray spectrum of CTB 37A is well fitted by two components, a single-temperature ionization equilibrium component (VMEKAL) with solar abundances, an electron temperature of kT e ∼ 0.6 keV, absorbing column density of N H ∼ 3 × 10 22 cm −2 and a power-law component with photon index of Γ ∼ 1.6. The X-ray spectrum of CTB 37A is characterized by clearly detected K-shell emission lines of Mg, Si, S, and Ar. The plasma with solar abundances supports the idea that the X-ray emission originates from the shocked interstellar material. The ambient gas density, and age of the remnant are estimated to be ∼1f −1/2 cm −3 and ∼3×10 4 f 1/2 yr, respectively. The center-filling X-ray emission surrounded by a shell-like radio structure and other X-ray properties indicate that this remnant would be a new member of mixed-morphology supernova remnant class.

In this paper, we present the results from a Suzaku observation of the Galactic supernova remnant G272.2−3.2. The spectra of G272.2−3.2 are well fitted by a single‐temperature variable abundance non‐equilibrium ionization (VNEI) model with an electron temperature kTe∼ 0.77 keV, an ionization time‐scale τ∼ 6.5 × 1010 cm−3 s and an absorbing column density NH∼ 1.1 × 1022 cm−2. We have detected enhanced abundances of Si, S, Ca, Fe and Ni in the centre region, indicating that the X‐ray emission has an ejecta origin. We estimate that the electron density is ne∼ 0.48f−1/2 cm−3, the age is ∼4300f1/2 yr and the X‐ray total mass is Mx= 475f1/2 M⊙ by taking the distance to be d= 10 kpc. To understand the origin of the centrally peaked X‐ray emission of the remnant, we have studied the radial variations of the electron temperature and surface brightness. The relative abundances in the centre region suggest that G272.2−3.2 is the result of a Type Ia supernova explosion.

We present here the results of an X‐ray analysis of Galactic supernova remnant G346.6−0.2 observed with Suzaku. K‐shell emission lines of Mg, Si, S, Ca and Fe are detected clearly for the first time. Strong emission lines of Si and S imply that the X‐ray emission nature of G346.6−0.2 is ejecta‐dominated. The ejecta‐dominated emission is well fitted by a combined model consisting of a thermal plasma in non‐equilibrium ionization and a non‐thermal component, which can be regarded as synchrotron emission with a photon index of Γ∼ 0.6. An absorbing column density of NH∼ 2.1 × 1022 cm−2 is obtained from the best fit, implying a high‐density medium, high electron temperature of kTe∼ 1.2 keV and ionization time‐scale of net∼ 2.9 × 1011 cm−3 s, indicating that this remnant may be far from full ionization equilibrium. The relative abundances from the ejecta show that the remnant originates from a Type Ia supernova explosion.

We report the discovery of optical filamentary and diffuse emission from G182.4+4.3 using the 1.5‐m Russian–Turkish telescope. We present the optical CCD images obtained with the Hα filter, revealing the presence of mainly filamentary structure to the north‐west and filamentary and diffuse structure in the centre, south and north regions of the remnant. The bright optical filaments located in the north‐west and south regions are well correlated with the prominent radio shell of the remnant, strongly suggesting an association. From the flux‐calibrated CCD imaging, the average [S ii]/Hα ratio is found to be ∼0.9 and ∼1.1 for south and north‐west regions, respectively, which clearly indicates that the emission originates from shock‐heated gas. We also present the results of X‐ray data obtained from XMM–Newton, showing diffuse emission with a very low luminosity of ∼7.3 × 1031 erg s−1 at a distance of 3 kpc in the 0.3–10 keV energy band. Furthermore, we find a surprisingly low age of ∼4400 yr for this remnant, given its large radius of ∼22 pc.

In this paper, we present the analysis of a deep (99.6 ks) observation of G304.6+0.1 with the X‐ray Imaging Spectrometer on board the Suzaku satellite. The X‐ray spectral data are well fitted with a plasma model consisting of a thermal component, in collisional ionization equilibrium, and a non‐thermal component. The thermal emission is well fitted with the vmekal model with an electron temperature of kTe∼ 0.75 keV, a high absorbing column density of NH∼ 3.9 × 1022 cm−2 and near/lower solar abundances, which indicate that the X‐ray emitting plasma of G304.6+0.1 is dominated by a swept‐up ambient medium. The non‐thermal component is well fitted with a power‐law model with a photon index of Γ∼ 1.4. We have found a relatively high electron density ne∼ 2.3f−1/2 cm−3, an age t∼ 1.4 × 104f1/2 yr and an X‐ray emitting mass Mx∼ 380f1/2 M⊙ at an adopted distance of d= 10 kpc. Using the morphological and spectral X‐ray data, we confirm that the remnant is a new member of the mixed‐morphology supernova remnants.