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.
We report the results of our investigation on the possible existence of supernova remnants (SNRs) in the nearby galaxy, NGC 1569, using the CCD imaging and spectroscopic observations from the RTT150 telescope of TUG-TUBITAK in Antalya, Turkey for two different observing periods. Using [S ii]/Hα ≥ 0.4 standard criteria, the identification of 13 new SNR candidates for this galaxy is proposed for two different epochs. We found the [S ii]/Hα ratios ranging from 0.46-0.84 and Hα intensities ranging from (2.2-32) × 10 −15 erg cm −2 s −1 . [S ii]λλ6716/6731 average flux ratio is calculated from the optical spectra for only one possible SNR candidate. By using this ratio the electron density, N e , is estimated to be 121 ± 17 cm −3 and by using the [O iii]λ5007/Hβ ratio of the same spectrum, the shock wave velocity, V s , is estimated to be between 100 < Vs < 150 km s −1 . Using Chandra data, we find that out of 13 SNR candidates only 10 of them have yielded a spectrum with good statistics, confirming the existence of 10 SNR candidates with matched positions in X-ray region as well. We measure the 0.5-2 keV band flux down to 0.58 × 10 −15 erg cm −2 s −1 for 10 X-ray sources. Our spectral analysis revealed that spectra of the SNR candidates are best modelled with the Collisional Ionisation Equilibrium plasma with a temperature range of 0.84 keV < kT e < 1.36 keV.
Optical CCD imaging with Hα and [SII] filters and spectroscopic observations of the galactic supernova remnant G85.9-0.6 have been performed for the first time. The CCD image data are taken with the 1.5 m RussianTurkish Telescope (RTT150) at TÜBİTAK National Observatory (TUG) and spectral data are taken with the Bok 2.3 m telescope on Kitt Peak, AZ.The images are taken with narrow-band interference filters Hα, [SII] and their continuum.[SII]/Hα ratio image is performed. The ratio obtained from [SII]/Hα is found to be ∼0.42, indicating that the remnant interacts with HII regions. G85.9-0.6 shows diffuse-shell morphology.[SII]λλ6716/6731 average flux ratio is calculated from the spectra, and the electron density N e is obtained to be 395 cm −3 . From [OIII]/Hβ ratio, shock velocity has been estimated, pre-shock density of n c = 14 cm −3 , explosion energy of E = 9.2 × 10 50 ergs, interstellar extinction of E(B − V ) = 0.28, and neutral hydrogen column density of N(HI) = 1.53 × 10 21 cm −2 are reported.
We present here the optical CCD observations and long slit spectra of the galactic supernova remnants G59.5+0.1, G84.9+0.5 and G67.7+1.8, the first two being observed for the first time. The observations were carried out with the 1.5 m Russian-Turkish joint Telescope (RTT150) at TÜBİTAK National Observatory (TUG). The images were taken with Hα, [SII] and their continuum filters. After subtracting the continuum from Hα and [SII], [SII]/Hα ratio is obtained. The average ratio is found to be 0.41 for G59.5+0.1 and 0.44 for G84.9+0.5, in a very good agreement with the ratios obtained from the optical spectra, namely 0.46 and 0.40, respectively, indicating that these remnants are close to, or interacting with, HII regions.G59.5+0.1 and G84.9+0.5 remnants show diffuse-shell morphology while G67.7+1.8 shows arc-shell morphology. From the emission lines of the spectra, the electron density N e , pre-shock density n c , explosion energy E, interstellar extinction E(B-V), and neutral hydrogen column density N(HI) are calculated and shock velocity V s is estimated for these remnants.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.