199 research outputs found

    Optical Imaging and Spectroscopic Observation of the Galactic Supernova Remnant G85.9-0.6

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    Optical CCD imaging with Hα\alpha 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 1.5m Russian-Turkish Telescope (RTT150) at TUBITAK 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\alpha, [SII] and their continuum. [SII]/Hα\alpha ratio image is performed. The ratio obtained from [SII]/Hα\alpha is found to be ∼\sim0.42, indicating that the remnant interacts with HII regions. G85.9-0.6 shows diffuse-shell morphology. [SII]λλ6716/6731\lambda\lambda 6716/6731 average flux ratio is calculated from the spectra, and the electron density NeN_{e} is obtained to be 395 cm−3cm^{-3}. From [OIII]/Hβ\beta ratio, shock velocity has been estimated, pre-shock density of nc=14n_{c}=14 cm−3cm^{-3}, explosion energy of E=9.2×1050E=9.2\times10^{50} ergs, interstellar extinction of E(B−V)=0.28E(B-V)=0.28, and neutral hydrogen column density of N(HI)=1.53×1021N(HI)=1.53\times10^{21} cm−2cm^{-2} are reported.Comment: 20 pages, 4 tables, 4 figures. Accepted for publication in Astrophysics & Space Scienc

    The first optical light from the supernova remnant G182.4+4.3 located in the Galactic anti-centre region

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    We report the discovery of optical filamentary and diffuse emission from G182.4+4.3 using 1.5-m Russian-Turkish telescope. We present the optical CCD images obtained with Halpha filter revealing the presence of mainly filamentary structure at the northwest, filamentary and diffuse structure at the centre, south and north regions of the remnant. The bright optical filaments located in northwest and south regions are well correlated with the prominent radio shell of the remnant strongly suggesting their association. From the flux-calibrated CCD imaging, the average [SII]/Halpha ratio is found to be ~0.9 and ~1.1 for south and northwest regions, which clearly indicates that the emission originates from the shock heated gas. We also present the results of X-ray data obtained from XMM-Newton that show diffuse emission with a very low luminosity of ~7.3x10^31 erg s^-1 at a distance of 3 kpc in 0.3-10 keV energy band. Furthermore, we find a surprisingly young age of ~4400 yr for this remnant with such a large radius of ~22 pc.Comment: 9 pages, 6 figures and 1 table, Accepted for publication in MNRA

    A deep X-ray observation of supernova remnant G304.6+0.1 (Kes 17) with Suzaku

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    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 {\it 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 VMEKAL model with an electron temperature of kTe∼0.75kT_{\rm e}\sim 0.75 keV, a high absorbing column density of NH∼3.9×1022N_{\rm H}\sim 3.9\times10^{22} cm−2\rm cm^{-2} and near/lower solar abundances which indicate that the X-ray emitting plasma of G304.6 + 0.1 is dominated by swept-up ambient medium. The non-thermal component is well fitted with a power-law model with photon index of Γ∼1.4\Gamma \sim 1.4. We found a relatively high electron density ne∼2.3f−1/2n_{\rm e}\sim 2.3f^{-1/2} cm−3^{-3}, age tt ∼1.4×104f1/2\sim 1.4\times10^4f^{1/2} yr, and X-ray emitting mass Mx∼380f1/2M_{\rm x}\sim 380f^{1/2} {M\sun} 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 mixed-morphology supernova remnants.Comment: 8 pages, 4 figures, 2 table

    Ejecta detection in the middle-aged Galactic supernova remnant G296.1-0.5 observed with Suzaku

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    In this paper, we report the detection of ejecta in the middle-aged Galactic supernova remnant G296.1-0.5 with the X-ray Imaging Spectrometer onboard the Suzaku satellite. The spectra of three lobes, north, southeast and southwest and inter-lobe regions, consist of soft (0.3-2.0 keV) emission originated from non-equilibrium ionization plasma. In north, southeast and inter-lobe regions, the thermal emission can be represented by a one-component, in southwest region it can be represented by two- component non-equilibrium ionization (VNEI) model. The spectra of studied regions have lines of N, O, Ne, Mg and Si elements. Si emission from this remnant is shown for the first time in this work. Enhanced abundances of Ne, Mg and Si elements obtained show the ejecta contribution in all regions. Assuming that the remnant is in Sedov phase, we obtained ambient density n0 ~ 0.45 cm-3, age t ~ 2.8 x 104 yr, shock velocity Vs ~ 320 km s-1, shock temperature Ts ~ 1.2 x 106 K, and swept-up mass Msw ~ 340 M at an adopted distance of d=3 kpc.Comment: 9 pages, 5 figures, 2 table

    Suzaku Observations of Ejecta-Dominated Galactic Supernova Remnant G346.6-0.2

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    We present here the results of the X-ray analysis of Galactic supernova remnant G346.6-0.2 observed with {\it 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 X-ray emission nature of G346.6-0.2 is ejecta-dominated. The ejecta-dominated emission is well fitted with a combined model consisting of thermal plasma in non-equilibrium ionization and a non-thermal component, which can be regarded as synchrotron emission with a photon index of Γ\Gamma ∼0.6\sim 0.6. Absorbing column density of NH∼2.1×1022N_{\rm H}\sim2.1\times10^{22} cm−2{\rm cm^{-2}} is obtained from the best-fitting implying a high-density medium, high electron temperature of kTe∼1.2kT_{\rm e}\sim1.2 keV, and ionization timescale of net∼2.9×1011n_{\rm e}t\sim2.9\times10^{11} cm−3s{\rm 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.Comment: 7 pages, 4 figur

    {\it Suzaku} observation of Galactic supernova remnant CTB 37A (G348.5+0.1)

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    We present here the results of the observation of CTB 37A obtained with the X-ray Imaging Spectrometer onboard the {\it 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 kTe∼0.6kT_{\rm e}\sim0.6 keV, absorbing column density of NH∼3×1022N_{\rm H}\sim3\times10^{22} cm−2{\rm cm^{-2}} and a power-law component with photon index of Γ\Gamma ∼1.6\sim 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\sim1f^{-1/2}cm−3{\rm cm^{-3}} and ∼3×104f1/2\sim3\times10^{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

    HPV testing on self collected cervicovaginal lavage specimens as screening method for women who do not attend cervical screening: cohort study

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    Objective To determine whether offering self sampling of cervicovaginal material for high risk human papillomavirus (HPV) testing is an effective screening method for women who do not attend regular cervical screening programmes

    The contribution of HPV18 to cervical cancer is underestimated using high-grade CIN as a measure of screening efficiency

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    In one geographical area, 14 high-risk human papillomavirus types in cervical intraepithelial neoplasia (CIN2/3; n=139) and cervical squamous cell carcinoma (SCC; n=84) were analysed. HPV18 was more prevalent in SCC than CIN2/3 (OR 9.8; 95% confidence interval: 2.5–39). Other high-risk types prevalences corresponded in CIN2/3 and SCC. Evaluations using CIN2/3 as a measure of efficiency underestimate the contribution of HPV18 to SCC
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