我们观察超新星遗迹(SNR)船尾座A在21厘米线与澳大利亚望远镜紧凑阵列的目的是确定系统的速度,因此,相应的运动学距离。对于紧凑的,在现场的背景源,我们得到的吸收光谱,通过应用两种方法:(a)减去轮廓上和关闭源连续发射,和(b)过滤傅立叶平面中的短空间频率,以消除大规模的发射。船尾座A外壳东部最亮的特征之一被发现是背景源,可能是河外星系。除去这个和以前已知的不相关的源的贡献,船尾座A的系统速度被限制在8和12 km s $^{-1}$之间,这使得这个源的距离为1.3 $\pm$ 0.3 kpc。从包括单碟和干涉数据的组合图像中,我们分析了星际氢的分布。我们认为,如果距离为$\lesssim$ 1.2 kpc,那么在$v \sim $ +8 km s $^{-1}$处的椭球环可能是船尾座A的祖先吹出的气泡的遗迹。与以前的出版物($v =$ +16 km s $^{-1}$和$d = $ 2.2 kpc)相比,新的系统速度和距离的主要结果是在东方没有一个致密的相互作用云来解释形态,以及壳层尺寸和中子星速度的减小,现在与统计值更好地吻合。
英文摘要:
We observed the supernova remnant (SNR) Puppis A in the 21 cm line with the Australia Telescope Compact Array with the aim of determining the systemic velocity and, hence, the corresponding kinematic distance. For the compact, background sources in the field, we obtain absorption spectra by applying two methods: (a) subtracting profiles on- and off-source towards continuum emission, and (b) filtering short spacial frequencies in the Fourier plane to remove large scale emission. One of the brightest features to the East of the shell of Puppis A was found to be a background source, probably extragalactic. Removing the contribution from this and the previously known unrelated sources, the systemic velocity of Puppis A turns out to be limited between 8 and 12 km s$^{-1}$, which places this source at a distance of 1.3 $\pm$ 0.3 kpc. From the combined images that include both single dish and interferometric data, we analyze the distribution of the interstellar hydrogen. We suggest that an ellipsoidal ring at $v \sim $+8 km s$^{-1}$ could be the relic of a bubble blown by the progenitor of Puppis A, provided the distance is $\lesssim$ 1.2 kpc. The main consequences of the new systemic velocity and distance as compared with previous publications ($v =$ +16 km s$^{-1}$ and $d = $2.2 kpc) are the absence of a dense interacting cloud to the East to explain the morphology, and the decrease of the shell size and the neutron star velocity, which are now in better agreement with statistical values.
Core-collapse supernova remnants are the gaseous nebulae of galactic interstellar media (ISM) formed after the explosive death of massive stars. Their morphology and emission properties depend both on the surrounding circumstellar structure shaped by the stellar wind-ISM interaction of the progenitor star and on the local conditions of the ambient medium. In the warm phase of the Galactic plane (n = 1/cm3, T = 8000 K), an organised magnetic field of strength 7 microG has profound consequences on the morphology of the wind bubble of massive stars at rest. In this paper we show through 2.5D magn…
We have carried out a study of the interstellar medium (ISM) toward a shell-like supernova remnant SNR Puppis A by using the NANTEN CO and ATCA HI data. We synthesized a comprehensive picture of the SNR radiation by combining the ISM data with the gamma-ray and X-ray distributions. The ISM, both atomic and molecular gas, is dense and highly clumpy, and is distributed all around the SNR, but mainly in the north-east. The CO distribution revealed an enhanced line intensity ratio of CO($J$ = 2-1)/($J$ = 1-0) transitions as well as CO line broadening, which indicate shock heating/acceleration. The…
We examine the evolution and emission of the supernova remnant (SNR) CTB109 using three-dimensional magnetohydrodynamics simulations. The SNR evolves in a medium divided by a plane interface into two media with different densities and pressure equilibrium. Our results reveal that a remnant with the characteristics of CTB109 is formed provided the supernova (SN) explosion takes place in the less dense medium and also if the interstellar magnetic field (ISMF) is almost uniform. Finally, we conclude that the quasiparallel mechanism can explain the brightness synchrotron emission and the position …
A signification fraction of Galactic massive stars (> 8Mo) are ejected from their parent cluster and supersonically sail away through the interstellar medium (ISM). The winds of these fast-moving stars blow asymmetric bubbles thus creating a circumstellar environment in which stars eventually die with a supernova explosion. The morphology of the resulting remnant is largely governed by the circumstellar medium of the defunct progenitor star. In this paper, we present 2D magneto-hydrodynamical simulations investigating the effect of the ISM magnetic field on the shape of the supernova remnants …
NGC6946 is a high star formation rate face-on spiral galaxy that has hosted ten supernovae since 1917. Not surprisingly, a large number of supernova remnants and candidates have been identified either as optical nebulae with high [S II]:H$α$ line ratios (147) or as compact non-thermal radio sources (35). However, there are only seven overlaps between these two samples. Here, we apply [Fe II] 1.644 $μ$m emission as a new diagnostic to search for supernova remnants in an attempt to resolve this discrepancy. [Fe II] is expected to be relatively strong in the radiative shocks of supernova remnants…
The X-ray emission from a supernova remnant is a powerful diagnostic of the state of its shocked plasma. The temperature and the emission measure are related to the energy of the explosion, the age of the remnant, and the density of the surrounding medium. Here we present the results of a study of the remnant population of the Small Magellanic Cloud. Progress in X-ray observations of remnants has resulted in a sample of 20 remnants in the Small Magellanic Clound with measured temperatures and emission measures. We apply spherically symmetric supernova remnant evolution models to this set of re…