Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userXMM-Newton observation of the Tycho Supernova Remnant
77
0
0.0
(
0
)
Authors
A. Decourchelle
Ask ChatGPT about the research
No Arabic abstract
We present the observation of the Tycho supernova remnant obtained with the EPIC and RGS instruments onboard the XMM-Newton satellite. We compare images and azimuthally averaged radial profiles in emission lines from different elements (silicon and iron) and different transition lines of iron (Fe L and Fe K). While the Fe XVII L line and Si XIII K line images are globally spatially coincident, the Fe K emission clearly peaks at a smaller radius, indicating a higher temperature toward the reverse shock. This is qualitatively the profile expected when the reverse shock, after travelling through the outer power-law density profile, has entered the central plateau of the ejecta. The high energy continuum map has an overall smooth distribution, with a similar extent to the radio emission. Its radial profile peaks further out than the lines emission. Brighter and harder continuum regions are observed with a rough bipolar symmetry in the eastern and western edges. The spectral analysis of the southeastern knots supports spatial variations of the relative abundance of silicon and iron, which implies an incomplete mixing of the silicon and iron layers.
rate research
Read More
The supernova remnant (SNR) W51C is a Galactic object located in a strongly inhomogeneous interstellar medium with signs of an interaction of the SNR blast wave with dense molecular gas. Diffuse X-ray emission from the interior of the SNR can reveal element abundances in the different emission regions and shed light on the type of supernova (SN) explosion and its progenitor. The hard X-ray emission helps to identify possible candidates for a pulsar formed in the SN explosion and for its pulsar wind nebula (PWN). We have analysed X-ray data obtained with XMM-Newton. Spectral analyses in selected regions were performed. Ejecta emission in the bright western part of the SNR, located next to a complex of dense molecular gas, was confirmed. The Ne and Mg abundances suggest a massive progenitor with a mass of > 20 M_sun. Two extended regions emitting hard X-rays were identified (corresponding to the known sources [KLS2002] HX3 west and CXO J192318.5+140305 discovered with ASCA and Chandra, respectively), each of which has an additional point source inside and shows a power-law spectrum with Gamma ~ 1.8. Based on their X-ray emission, both sources can be classified as PWN candidates.
We report on an {it XMM-Newton} observation of the supernova remnant (SNR) object{DEM L241} in the Large Magellanic Cloud. In the soft band image, the emission shows an elongated structure, like a killifish, with a central compact source. The compact source is point-like, and named as XMMU J053559.3$-$673509. The source spectrum is well reproduced with a power-law model with a photon index of $Gamma = 1.57$ (1.51--1.62) and the intrinsic luminosity is $2.2times 10^{35} mathrm{ergs s^{-1}}$ in the 0.5--10.0 keV band, with the assumed distance of 50 kpc. The source has neither significant coherent pulsations in $2.0times 10^{-3}$ Hz--8.0 Hz, nor time variabilities. Its luminosity and spectrum suggest that the source might be a pulsar wind nebula (PWN) in DEM L241. The spectral feature classifies this source into rather bright and hard PWN, which is similar to those in Kes 75 and B0540$-$693. The elongated diffuse structure can be divided into a ``Head and ``Tail, and both have soft and line-rich spectra. Their spectra are well reproduced by a plane-parallel shock plasma ({it vpshock}) model with a temperature of 0.3--0.4 keV and over-abundance in O and Ne and a relative under-abundance in Fe. Such an abundance pattern and the morphology imply that the emission is from the ejecta of the SNR, and that the progenitor of DEM L241 is a very massive star, more than 20 Msun. This result is also supported by the existence of the central point source and an OB star association, LH 88. The total thermal energy and plasma mass are $sim 4times 10^{50}$ ergs and $sim 200$ Msun, respectively.
Aims. We report the first detailed X-ray study of the supernova remnant (SNR) G304.6+0.1, achieved with the XMM-Newton mission. Methods. The powerful imaging capability of XMM-Newton was used to study the X-ray characteristics of the remnant at different energy ranges. The X-ray morphology and spectral properties were analyzed. In addittion, radio and mid-infrared data obtained with the Molonglo Observatory Synthesis Telescope and the Spitzer Space Telescope were used to study the association with the detected X-ray emission and to understand the structure of the SNR at differents wavelengths. Results. The SNR shows an extended and arc-like internal structure in the X-ray band with out a compact point-like source inside the remnant. We find a high column density of NH in the range 2.5-3.5x1022 cm-2, which supports a relatively distant location (d $geq$ 9.7 kpc). The X-ray spectrum exhibits at least three emission lines, indicating that the X-ray emission has a thin thermal plasma origin, although a non-thermal contribution cannot be discarded. The spectra of three different regions (north, center and south) are well represented by a combination of a non-equilibrium ionization (PSHOCK) and a power-law (PL) model. The mid-infrared observations show a bright filamentary structure along the north-south direction coincident with the NW radio shell. This suggests that Kes 17 is propagating in a non-uniform environment with high density and that the shock front is interacting with several adjacent massive molecular clouds. The good correspondence of radio and mid-infrared emissions suggests that the filamentary features are caused by shock compression. The X-ray characteristics and well-known radio parameters indicate that G304.6+0.1 is a middle-aged SNR (2.8-6.4)x104 yr old and a new member of the recently proposed group of mixed-morphology SNRs.
We present an X-ray imaging and spectroscopic study of the molecular cloud interacting mixed-morphology (MM) supernova remnant (SNR) G346.6-0.2 using XMM-Newton. The X-ray spectrum of the remnant is well described by a recombining plasma that most likely arises from adiabatic cooling, and has sub-solar abundances of Mg, Si, and S. Our fits also suggest the presence of either an additional power-law component with a photon index of $sim$2, or an additional thermal component with a temperature of $sim$2.0 keV. We investigate the possible origin of this component and suggest that it could arise from either the Galactic ridge X-ray emission, an unidentified pulsar wind nebula or X-ray synchrotron emission from high-energy particles accelerated at the shock. However, deeper, high resolution observations of this object are needed to shed light on the presence and origin of this feature. Based on its morphology, its Galactic latitude, the density of the surrounding environment and its association with a dense molecular cloud, G346.6-0.2 most likely arises from a massive progenitor that underwent core-collapse.
We present an analysis of the chemical abundances of the star Tycho G in the direction of the remnant of supernova (SN) 1572, based on Keck high-resolution optical spectra. The stellar parameters of this star are found to be those of a G-type subgiant with $T_{mathrm{eff}} = 5900 pm 100$ K, loggl $ = 3.85 pm 0.30$ dex, and $mathrm{[Fe/H]} = -0.05 pm 0.09$. This determination agrees with the stellar parameters derived for the star in a previous survey for the possible companion star of SN 1572 (Ruiz-Lapuente et al. 2004). The chemical abundances follow the Galactic trends, except for Ni, which is overabundant relative to Fe, $[{rm Ni/Fe}] $ $=$ 0.16 $pm$ 0.04. Co is slightly overabundant (at a low significance level). These enhancements in Fe-peak elements could have originated from pollution by the supernova ejecta. We find a surprisingly high Li abundance for a star that has evolved away from the main sequence. We discuss these findings in the context of companion stars of supernovae.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
