We present results from {\it XMM-Newton/RGS} observations of prominent knots in the southest portion of Tycho's supernova remnant, known to be the remnant of a Type Ia SN in 1572 C.E. By dispersing the photons from these knots out of the remnant with very little emission in front of or behind them, we obtained the nearly uncontaminated spectra of the knots. In the southernmost knot, the RGS successfully resolved numerous emission lines from Si, Ne, O He$α$ and Ly$α$, and Fe L-shell. This is the first clear detection of O lines in Tycho's SNR. Line broadening was measured to be $\sim 3$ eV for the O He$α$ and $\sim 4.5$ eV for Fe L lines. If we attribute the broadening to pure thermal Doppler effects, then we obtain kT$_{O}$ and kT$_{Fe}$ to be $\sim 400$ keV and 1.5 MeV, respectively. These temperatures can be explained by heating in a reverse shock with a shock velocity of $\sim 3500$ km s$^{-1}$. The abundances obtained from fitting the RGS and MOS data together imply substantially elevated amounts of these materials, confirming previous studies that the knots are heated by a reverse shock, and thus contain ejecta material from the supernova. We are unable to find a Type Ia explosion model that reproduces these abundances, but this is likely the result of this knot being too small to extrapolate to the entire remnant.
Dynamics of X-Ray-Emitting Ejecta in the Oxygen-Rich Supernova Remnant Puppis A Revealed by the XMM-Newton RGS
利用XMM-牛顿号上反射光栅光谱仪（RGS）前所未有的光谱分辨率，我们揭示了富氧超新星遗迹船尾座A中发射X射线的喷出物的动力学。RGS光谱显示出突出的K壳层线，包括O VII He_alpha禁戒和共振，O VIII Ly_alpha，O VIII Ly_beta和Ne IX He_alpha共振，这些线来自与光学富氧细丝（遗迹东北部所谓的Omega细丝）位置一致的喷出物结。我们发现，线的质心蓝移了1480+/-140+/-60 km/s（第一和第二项误差分别是测量和校准不确定性），这是完全一致的光学欧米茄灯丝。在654 eV（对应于O VIII Ly_alpha）处获得的谱线展宽小于~0.9 eV，表明氧温度小于~30 keV。对XMM-牛顿MOS谱的分析表明，电子温度约为0.8 keV，电离时标约为2 e10 cm^-3 s。我们表明，氧和电子的温度以及电离时标可以调和，如果喷出物结被加热的碰撞冲击，其速度是~600-1200公里/秒，随后由于库仑相互作用平衡。RGS光谱还显示了位于残骸东北边缘附近的另一个喷出物特征的相对较弱的K壳层线，从中我们测量到650+/-70+/-60 km/s的向红多普勒速度。
We present our velocity measurements of 59 clumpy, metal-rich ejecta knots in the supernova remnant (SNR) of SN 1572 (Tycho). We use our 450 ks Chandra High Energy Transmission Grating Spectrometer observation to measure the Doppler shift of the He-like Si K$α$ line-center wavelength emitted from these knots to find their line-of-sight (radial) velocities ($v_r$). We find $v_r$ up to $\sim$ 5500 km s$^{-1}$, with roughly consistent speeds between blueshifted and redshifted ejecta knots. We also measure the proper motions (PMs) for our sample based on archival Chandra Advanced CCD Imaging Spect…
The Three-Dimensional Expansion of the Ejecta from Tycho's Supernova Remnant
我们提出了第一个三维测量的各种喷出物结的速度在第谷的超新星遗迹，已知导致Ia型爆炸。钱德拉X射线观测从2003年到2015年的12年基线，使我们能够测量近60个富硅喷出物的自行，给我们天空平面的速度。对于视线速度，我们使用两种不同的方法：一个非平衡电离模型适合强Si和S线在1.2 - 2.8 keV的制度，和一个适合的一系列高斯线组成。这些方法给出了一致的结果，使我们能够确定每个结的红色或蓝移。假设距离为3.5千秒差距，我们发现总速度的范围为2400至6600 km s $^{-1}$，平均值为4430 km s $^{-1}$。我们发现有几个区域的喷出物结已经超过了前激波。这些区域的自行超过6000 km s $^{-1}$。一些Ia型超新星爆炸模型预测喷出物的速度不对称。我们没有发现这样的速度不对称性在第谷，并讨论我们的研究结果，根据各种爆炸模型，有利于那些延迟爆轰模型相对激烈和对称的爆燃。最后，我们比较测量与模型的残余物的演变，包括光滑和clujeaghte喷出物配置文件，发现这两个喷出物配置文件可以容纳的意见。
The Single-degenerate Binary Origin of Tycho's Supernova as Traced by the Stripped Envelope of the Companion
我们提出，一个非热的X射线弧内的第谷超新星（SN）的残余代表SN喷出物和伴星的信封之间的相互作用在爆炸的影响。残余物的X射线辐射进一步显示了一个明显的阴影，由电弧投射在爆炸地点的相反方向，与被外壳阻挡的SN喷出物一致。这种情况支持第谷SN的单一简并双星起源。X射线弧的性质，以及Ruiz-Lapuente等人（2004年）和Hernández等人先前对伴星候选者及其空间速度的探测。（2009），使我们能够进一步推断：1）祖先双星的周期为4.9 $^{+5.3}_{-3.0}$天，2）伴星的反冲速度为42 $\pm$ 30 km s $^{-1}$，3）剥离包层质量约为0.0016（$\leq0.0083$）$M_{\sun}$。但我们注意到，伴随候选的性质仍在争论中，上述参数需要根据伴随候选的实际性质进行修改。还需要进一步的工作来测量电弧的适当运动，并检查从电弧中观察到的相互作用发射X射线量的能力，以验证当前的情况。
The 2021 outburst of the symbiotic recurrent nova RS Oph was observed with the Chandra High Energy Transmission Gratings (HETG) on day 18 after optical maximum and with XMM-Newton and its Reflection Grating Spectrographs (RGS) on day 21, before the supersoft X-ray source emerged and when the emission was due to shocked ejecta. The absorbed flux in the HETG 1.3-31 Angstrom range was 2.6 x 10(-10) erg/cm(-2)/s, three orders of magnitude lower than the gamma-ray flux measured on the same date. The spectra are well fitted with two components of thermal plasma in collisional ionization equilibrium,…
Several explosions of thermonuclear supernovae (SNe Ia) have been found to exhibit deviations from spherical symmetry upon closer inspection. Examples are the gamma-ray lines from SN 2014J as measured by INTEGRAL/SPI, and morphology information from radioactive isotopes in older remnants such as Tycho. A systematic study on the effects of parameters such as ignition geometry and burning morphology in SNe Ia is still missing. We use a 2D hydrodynamics code with post-processing nucleosynthesis and simulate the double detonations in a sub-Chandrasekhar mass carbon-oxygen white dwarf starting from…
Deciphering the explosion mechanism of Type-Ia SNe using their remnants I: general properties and a case study on Tycho's SNR
University of Virginia（弗吉尼亚大学）；Virginia Institute for Theoretical Astronomy, University of Virginia（弗吉尼亚大学理论天体物理研究所）；University of Pittsburgh（匹兹堡大学）；South African Astronomical Observatory（南非天文台）；University of Cape Town（开普敦大学）；NITheCS National Institute for Theoretical and Computational Sciences, South Africa（南非国家理论与计算科学研究所）
