The (Re-)Discovery of G350.1-0.3: A Young, Luminous Supernova Remnant and Its Neutron Star (original) (raw)
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Discovery of thermal X-ray emission in the supernova remnant G337.8-0.1 (Kes 41)
Astronomy and Astrophysics, 2008
Aims. We report here on the first detection at X-ray wavelengths of the Supernova Remnant (SNR) G337.8−0.1, carried out with the XMM-Newton Observatory. Methods. Using the X-ray observations, we studied the X-ray morphology of the remnant at different energy ranges, analysed the spectral properties and investigated a possible variable behavior. Results. The SNR shows a diffuse filled-center structure in the X-ray region with an absence of a compact source in its center. We find a high column density of N H > 6.9×10 22 cm −2 , which supports a relatively distant location (d ≥ 7 kpc). The X-ray spectrum exhibits emission lines, indicating that the X-ray emission has a thin thermal plasma origin, and is well represented by a non-equilibrium ionization (NEI) plasma model. The X-ray characteristics and well-known radio parameters show that G337.8−0.1 belongs to the emerging class of mixed-morphology (MM) SNRs.
XMM‐Newton , Chandra , and CGPS observations of the Supernova Remnants G85.4+0.7 and G85.9−0.6
The Astrophysical Journal, 2008
We present an XMM-Newton detection of two low radio surface brightness SNRs, G85.4+0.7 and G85.9−0.6, discovered with the Canadian Galactic Plane Survey (CGPS). High-resolution XMM-Newton images revealing the morphology of the diffuse emission, as well as discrete point sources, are presented and correlated with radio and Chandra images. The new data also permit a spectroscopic analysis of the diffuse emission regions, and a spectroscopic and timing analysis of the point sources. Distances have been determined from H I and CO data to be 3.5 ± 1.0 kpc for SNR G85.4+0.7 and 4.8 ± 1.6 kpc for SNR G85.9−0.6.
The Astrophysical Journal, 2007
We present X-ray, infrared and radio observations of the field centered on X-ray source 1E 1547.0-5408 in the Galactic Plane. Analysis of a new Chandra observation of this source shows it is unresolved at arc-second resolution, and analysis of a new XMM observation shows that its X-ray spectrum is best described by an absorbed power-law and blackbody model. A comparison of the X-ray flux observed from 1E 1547.0-5408 between 1980 and 2006 by Einstein, ASCA, XMM, and Chandra reveals that its absorbed 0.5-10 keV X-ray flux decreased significantly during this period, from ∼ 2×10 −12 ergs cm −2 s −1 to ∼ 3 × 10 −13 ergs cm −2 . No pulsations in the X-ray emission from 1E 1547.0-5408 were observed during the most recent XMM observation, which allows us to put a 5σ confidence upper limit of 14% for the 0.5-10 keV peak-to-peak pulsed fraction (for sinusoidal pulses with periods slower than 1.8s). A near-infrared observation of this field shows a source with magnitude K s = 15.9 ± 0.2 near the position of 1E 1547.0-5408, but the implied X-ray to infrared flux ratio indicates the infrared emission is most likely from an unrelated field source, allowing us to limit the IR magnitude of any counterpart to 1E 1547.0-5408 to 17.5. Archival radio observations reveal that 1E 1547.0-5408 sits at the center of a faint, small (4 ′ diameter) radio shell, G327.24-0.13, which is possibly a previously unidentified supernova remnant. The X-ray properties of 1E 1547.0-5408 suggest that this source is a magnetar -a young neutron star whose X-ray emission is powered by the decay of its extremely strong magnetic field, B ∼ 10 14−15 G. The spatial coincidence between this source and G327.24-0.13 suggests that 1E 1547.0-5408 is associated with a young supernova remnant, supporting a neutron star interpretation. Additional observations are needed to confirm the nature of both 1E 1547.0-5408 and G327.24-0.13, and to determine whether these sources are physically associated. If confirmed, this pair will be an important addition to the small number of known associations between magnetars and supernova remnants.
G337.2+0.1: A new X-ray supernova remnant?
Astronomy and Astrophysics, 2005
We present evidence supporting a SNR origin for the radio source G337.2+0.1, which was discovered along the line of sight to the Norma spiral arm in the MOST 843-MHz radio survey. The radio source is spatially superposed to the unidentified ASCA source AX J1635.9-4719. An analysis of this latter source reveals that its X-ray spectrum, extended nature, and non-variable flux are consistent with what is expected for a SNR. In addition, we have used HI-line observations of the region to look for any effect of the presumed remnant on the ISM. We have found a well-defined minimum centered at the position of the radio source in the velocity range of ∼ −25 to −19 km s −1 . This feature appears as a sharp absorption dip in the spectrum that might be produced when the continuum emission from the SNR candidate is absorbed by foreground gas. Hence we have used it to constrain the distance to the source, which seems to be a young (age ∼ a few 10 3 yr) and distant (d ∼ 14 kpc) SNR. G337.2+0.1 and AX J1635.9-4719 would be the radio/X-ray manifestations of this remnant.
An XMM-Newton Study of the Bright, Nearby Supernova Remnant G296. 1-0.5
2011
We present a detailed study of the supernova remnant G296.1-0.5, performed using observations with the EPIC and RGS instruments of the XMM-Newton satellite. G296.1-0.5 is a bright remnant that displays an incomplete multiple-shell morphology in both its radio and X-ray images. We use a set of observations towards G296.1-0.5, from three distinct pointings of EPIC, in order to perform a thorough spatial and spectral analysis of this remnant, and hence determine what type of progenitor gave rise to the supernova explosion, and describe the evolutionary state of the SNR. Our XMM-Newton observations establish that the spectral characteristics are consistent across the X-ray bright regions of the object, and are best described by a model of the emission from a nonequilibrium ionization collisional plasma. The study reveals that the emission from the shell is characterized by an excess of N and an underabundance of O, which is typical of wind material from red supergiant (RSG) and Wolf-Rayet (WR) stars. Additionally, we have detected transient X-ray source 2XMMi J115004.8-622442 at the edge of the SNR whose properties suggest that it is the result of stellar flare, and we discuss its nature in more detail.
XMM- Newton detection of the supernova remnant G304.6 + 0.1 (Kes 17)
Astronomy & Astrophysics, 2010
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 N H in the range 2.5-3.5×10 22 cm −2 , which supports a relatively distant location (d ≥ 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)×10 4 yr old and a new member of the recently proposed group of mixed-morphology SNRs.
An XMM-Newton Study of the Mixed-morphology Supernova Remnant G346.6-0.2
APJ, 2017
We present an X-ray imaging and spectroscopic study of the molecular cloud interacting mixed-morphology supernova remnant 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 subsolar abundances of Mg, Si, and S. Our fits also suggest the presence of either an additional power-law component with a photon index of ∼2 or an additional thermal component with a temperature of ∼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.
An X-ray study of the SNR G344.7-0.1 and the central object CXOU J170357.8-414302
2010
Aims. We report results of an X-ray study of the supernova remnant (SNR) G344.7-0.1 and the point-like X-ray source located at the geometrical center of the SNR radio structure. Methods. The morphology and spectral properties of the remnant and the central X-ray point-like source were studied using data from the XMM-Newton and Chandra satellites. Archival radio data and infrared Spitzer observations at 8 and 24 µm were used to compare and study its multi-band properties at different wavelengths. Results. The XMM-Newton and Chandra observations reveal that the overall X-ray emission of G344.7-0.1 is extended and correlates very well with regions of bright radio and infrared emission. The X-ray spectrum is dominated by prominent atomic emission lines. These characteristics suggest that the X-ray emission originated in a thin thermal plasma, whose radiation is represented well by a plane-parallel shock plasma model (PSHOCK). Our study favors the scenario in which G344.7-0.1 is a 6 × 10 3 year old SNR expanding in a medium with a high density gradient and is most likely encountering a molecular cloud on the western side. In addition, we report the discovery of a soft point-like X-ray source located at the geometrical center of the radio SNR structure. The object presents some characteristics of the so-called compact central objects (CCO). However, its neutral hydrogen absorption column (N H ) is inconsistent with that of the SNR. Coincident with the position of the source, we found infrared and optical objects with typical early-K star characteristics. The X-ray source may be a foreground star or the CCO associated with the SNR. If this latter possibility were confirmed, the point-like source would be the farthest CCO detected so far and the eighth member of the new population of isolated and weakly magnetized neutron stars.
Discovery of X-rays from the supernova remnant G0.9+0.1
Nuclear Physics B - Proceedings Supplements, 1999
During the BeppoSAX survey of the Galactic Center region, we have discovered X-ray emission from the central region of the supernova remnant G0.9+0.1. The high interstellar absorption (NH ∼ 3 × 10 23 cm −2) is consistent with a distance of order of 10 kpc and, correspondingly, an X-ray luminosity of ∼10 35 erg s −1. Although we cannot completely rule out a thermal origin of the X-ray emission, its small angular extent (radius ∼ 2), the good fit with a power law, the presence of a flat spectrum radio core, and the estimated SNR age of a few thousand years, favour the interpretation in terms of synchrotron emission powered by a young, energetic pulsar.
Discovery of a Compact X‐Ray Source in the LMC Supernova Remnant N23 withChandra
The Astrophysical Journal, 2006
An X-ray compact source was discovered with Chandra in a supernova remnant (SNR) N23, located in the Large Magellanic Cloud. The compact source (CXOU J050552.3−680141) is seen in only the hard band (> 2 keV) image of N23, while the soft band image (< 2 keV) shows diffuse emission of the SNR, with an extent of ∼ 60 ′′ × 80 ′′. The compact source is located at almost the center of N23, and there is no identifiable object for the source from previous observations at any other wavelength. The source spectrum is best explained by a power-law model with a photon index of Γ = 2.2 +0.5 −0.3 and an absorption-corrected luminosity of L x = 1.0 × 10 34 ergs s −1 in the 0.5-10 keV band for a distance of 50 kpc. Neither pulsation nor time variability of the source was detected with this observation with a time resolution of 3.2 sec. These results correspond with those of Hughes et al. (2006), who carried out analysis independently around the same time as our work. Based on information from the best-fit power-law model, we suggest that the source emission is most likely from a rotation-powered pulsar and/or a pulsar wind nebula. It is generally inferred that the progenitor of N23 is a core-collapsed massive star.