scholarly journals High-Resolution X-Ray Spectroscopy of Galactic Supernova Remnants

2014 ◽  
Vol 1 (1) ◽  
pp. 200-204
Author(s):  
Satoru Katsuda ◽  
Hiroshi Tsunemi
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Line Emission ◽  
Collisionless Shock ◽  
Reverse Shock ◽  
X Ray ◽  
Upper Limit ◽  
Hot Plasma ◽  
Forward Shock ◽  
Intensity Ratios

High-resolution X-ray spectroscopy of Galactic supernova remnants (SNRs), based on grating spectrometers onboard XMM-Newton and Chandra, has been revealing a variety of new astrophysical phenomena. Broadened oxygen lines for a northwestern compact knot in SN 1006 clearly show a high oxygen temperature of ~300 keV. The high temperature together with a lower electron temperature (<em>kT<sub>e</sub></em> ~ 1 keV) can be reasonably interpreted as temperature non-equilibration between electrons and oxygen behind a collisionless shock. An ejecta knot in the Puppis A SNR shows blueshifted line emission by ~ 1500kms<sup>-1</sup>. The line widths are fairly narrow in contrast to the SN 1006's knot; an upper limit of 0.9 eV is obtained for O VIII Lyα, which translates to an oxygen temperature of <em>kT<sub>O</sub></em> &lt; 30 keV. The low temperature suggests that the knot was heated by a reverse shock whose velocity is 4 times slower than that of a forward shock. Anomalous intensity ratios in O VII Heα lines, i.e., a stronger forbidden line than a resonance line, is found in a cloud-shock interaction region in Puppis A. The line ratio can be best explained by the charge-exchange emission that should arise at interfaces between the cold/warm clouds and the hot plasma. There are several other targets for which we plan to analyze high-quality grating data prior to the operation of the soft X-ray spectrometer onboard Astro-H.

scholarly journals Diverse Features of the Multiwavelength Afterglows of Gamma-Ray Bursts: Natural or Special?

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
J. J. Geng ◽  
Y. F. Huang
Keyword(s):  
Black Holes ◽  
Numerical Method ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Shock Model ◽  
Reverse Shock ◽  
X Ray ◽  
Electron Positron ◽  
Forward Shock ◽  
Electron Positron Pair

The detection of optical rebrightenings and X-ray plateaus in the afterglows of gamma-ray bursts (GRBs) challenges the generic external shock model. Recently, we have developed a numerical method to calculate the dynamics of the system consisting of a forward shock and a reverse shock. Here, we briefly review the applications of this method in the afterglow theory. By relating these diverse features to the central engines of GRBs, we find that the steep optical rebrightenings would be caused by the fall-back accretion of black holes, while the shallow optical rebrightenings are the consequence of the injection of the electron-positron-pair wind from the central magnetar. These studies provide useful ways to probe the characteristics of GRB central engines.

scholarly journals An Accreting Stellar Binary Model for Active Periodic Fast Radio Bursts

2021 ◽  
Vol 922 (2) ◽  
pp. 98
Author(s):  
Can-Min Deng ◽  
Shu-Qing Zhong ◽  
Zi-Gao Dai
Keyword(s):  
Compact Object ◽  
Radio Bursts ◽  
Reverse Shock ◽  
X Ray ◽  
Highly Active ◽  
Surrounding Environment ◽  
Binary Model ◽  
Forward Shock ◽  
Long Lifetime

Abstract In this work, we propose an accreting stellar binary model for understanding the active periodic fast radio bursts (FRBs). The system consists of a stellar compact object (CO) and a donor star (DS) companion in an eccentric orbit, where the DS fills its own Roche lobe near the periastron. The CO accretes the material from the DS and then drives relativistic magnetic blobs. The interaction between the magnetic blobs and the stellar wind of the DS produces a pair of shocks. We find that both the reverse shock and the forward shock are likely to produce FRBs via the synchrotron maser mechanism. We show that this system can in principle sufficiently produce highly active FRBs with a long lifetime, and also can naturally explain the periodicity and the duty cycle of the activity that appeared in FRBs 180916 and 121102. The radio nebula excited by the long-term injection of magnetic blobs into the surrounding environment may account for the associated persistent radio source. In addiction, we discuss the possible multiwavelength counterparts of FRB 180916 in the context of this model. Finally, we encourage the search for FRBs in ultraluminous X-ray sources.

scholarly journals SolpeX: the soft X-ray flare polarimeter–spectrometer for the ISS

2014 ◽  
Vol 10 (S305) ◽  
pp. 114-120
Author(s):  
Janusz Sylwester ◽  
Stefan Płocieniak ◽  
Jarosław Bakała ◽  
Żaneta Szaforz ◽  
Marek Stȩślicki ◽  
...  
Keyword(s):  
Solar Flares ◽  
Line Emission ◽  
Impulsive Phase ◽  
Particle Beams ◽  
X Ray ◽  
Hot Plasma ◽  
Spectral Imager ◽  
Polarized Bremsstrahlung ◽  
Made In ◽  
Fast Rotating

AbstractWe present the innovative soft X-ray spectro-polarimeter, SolpeX. This instrument consists of three functionally independent blocks. They are to be included into the Russian instrument KORTES, to be mounted onboard the ISS. The three SolpeX units are: a simple pin-hole X-ray spectral imager, a polarimeter, and a fast-rotating drum multiple-flat-crystal Bragg spectrometer. Such a combination of measuring blocks will offer a new opportunity to reliably measure possible X-ray polarization and spectra of solar flares, in particular during the impulsive phase. Polarized Bremsstrahlung and line emission due to the presence of directed particle beams will be detected, and measurements of the velocities of evaporated hot plasma will be made. In this paper we discuss the details of the construction of the SolpeX units. The delivery of KORTES with SolpeX to the ISS is expected to happen in 2017/2018.

scholarly journals The dark matter interpretation of the 3.5-keV line is inconsistent with blank-sky observations

Science ◽  
2020 ◽  
Vol 367 (6485) ◽  
pp. 1465-1467 ◽  
Author(s):  
Christopher Dessert ◽  
Nicholas L. Rodd ◽  
Benjamin R. Safdi
Keyword(s):  
Dark Matter ◽  
Emission Line ◽  
Decay Rate ◽  
Milky Way ◽  
Line Emission ◽  
Mass Range ◽  
Sterile Neutrinos ◽  
X Ray ◽  
Upper Limit ◽  
Nearby Galaxies

Observations of nearby galaxies and galaxy clusters have reported an unexpected x-ray emission line around 3.5 kilo–electron volts (keV). Proposals to explain this line include decaying dark matter—in particular, that the decay of sterile neutrinos with a mass around 7 keV could match the available data. If this interpretation is correct, the 3.5-keV line should also be emitted by dark matter in the halo of the Milky Way. We used more than 30 megaseconds of XMM-Newton (X-ray Multi-Mirror Mission) blank-sky observations to test this hypothesis, finding no evidence of the 3.5-keV line emission from the Milky Way halo. We set an upper limit on the decay rate of dark matter in this mass range, which is inconsistent with the possibility that the 3.5-keV line originates from dark matter decay.

scholarly journals Radio and X-ray Study of SNRs in the Magellanic Clouds

1999 ◽  
Vol 192 ◽  
pp. 104-107
Author(s):  
M.D. Filipović ◽  
W. Pietsch ◽  
G. L. White ◽  
F. Haberl ◽  
L. Staveley-Smith ◽  
...  
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Magellanic Clouds ◽  
Radio Continuum ◽  
H Ii Regions ◽  
Complete Sample ◽  
X Ray ◽  
Compact Array

We present our high-resolution radio-continuum and X-ray study of supernova remnants (SNRs) in the Magellanic Clouds (MCs). These investigations are based on Australia Telescope Compact Array (ATCA) radio-continuum and ROSAT X-ray observations. Our main aim is to study a complete sample of the MC SNRs and H II regions.

scholarly journals Deciphering the nature of the pulsar wind nebula CTB 87 with XMM–Newton

2019 ◽  
Vol 491 (2) ◽  
pp. 3013-3021 ◽  
Author(s):  
B Guest ◽  
S Safi-Harb ◽  
A MacMaster ◽  
R Kothes ◽  
B Olmi ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Thermal Emission ◽  
Plasma Temperature ◽  
Evolutionary Stage ◽  
Reverse Shock ◽  
X Ray ◽  
Upper Limit ◽  
Supernova Shell ◽  
Pulsar Wind ◽  
Hydrodynamical Simulations

ABSTRACT CTB 87 (G74.9+1.2) is an evolved supernova remnant (SNR) which hosts a peculiar pulsar wind nebula (PWN). The X-ray peak is offset from that observed in radio and lies towards the edge of the radio nebula. The putative pulsar, CXOU J201609.2+371110, was first resolved with Chandra and is surrounded by a compact and a more extended X-ray nebula. Here, we use a deep XMM–Newton observation to examine the morphology and evolutionary stage of the PWN and to search for thermal emission expected from a supernova shell or reverse shock interaction with supernova ejecta. We do not find evidence of thermal X-ray emission from the SNR and place an upper limit on the electron density of 0.05 cm−3 for a plasma temperature kT ∼ 0.8 keV. The morphology and spectral properties are consistent with a ∼20-kyr-old relic PWN expanding into a stellar wind-blown bubble. We also present the first X-ray spectral index map from the PWN and show that we can reproduce its morphology by means of 2D axisymmetric relativistic hydrodynamical simulations.

Mixed-morphology supernova remnants: the case of SNR 0520–69.4 in the Large Magellanic Cloud

2020 ◽  
Vol 499 (3) ◽  
pp. 4213-4222
Author(s):  
I Ramírez-Ballinas ◽  
J Reyes-Iturbide ◽  
P Ambrocio-Cruz ◽  
R Gabbasov ◽  
M Rosado
Keyword(s):  
Supernova Remnants ◽  
Plasma Temperature ◽  
Optical Emission ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Physical Parameters ◽  
X Ray ◽  
Hot Plasma ◽  
Observatory Data ◽  
Fabry Perot

ABSTRACT We present observations in X-ray and optical emission of the supernova remnant (SNR) 0520–69.4 in the Large Magellanic Cloud. Using XMM–Newton observatory data, we produced images of the diffuse X-ray emission and spectra to obtain the X-ray parameters, such as luminosity and temperature, of hot plasma in the SNR. Diffuse X-ray emission with filled-centre morphology goes beyond the Hα region, suggesting that the hot gas escapes through the pores of the Hα shell. We fitted a model that has a plasma temperature of 1.1 × 107 K for an X-ray thermal luminosity of 3.3 × 1035 erg s−1. However, from Hα and [O iii] Fabry–Perot observations obtained with the Marseille Hα Survey of the Magellanic Clouds and the Milky Way at La Silla, European Southern Observatory, we are able to obtain physical parameters such as the velocity of the shock induced in the cloudlets emitting at optical wavelengths and the electron density of this gas. With the parameters described above, we test the model proposed by White & Long (1991, ApJ, 373, 543) for explaining the mixed-morphology observed.

scholarly journals High Resolution X-ray Images of Puppis a and IC 443

1983 ◽  
Vol 101 ◽  
pp. 289-293
Author(s):  
R. Petre ◽  
C. R. Canizares ◽  
P. F. Winkler ◽  
F. D. Seward ◽  
R. Willingale ◽  
...  
Keyword(s):  
High Resolution ◽  
Interstellar Medium ◽  
Molecular Cloud ◽  
Supernova Remnants ◽  
Surface Brightness ◽  
Middle Aged ◽  
X Ray ◽  
Giant Molecular Cloud

We present soft X-ray photomosaic images of two supernova remnants, Puppis A and IC 443, constructed from a series of exposures by the Einstein imaging instruments. The complex morphologies displayed in these images reflect the interaction between “middle-aged” supernova remnants and various components of the interstellar medium. Surface brightness variations across Puppis A suggest that inhomogeneities on scales from 0.2 to 30 pc are present in the interstellar medium, while the structure of IC 443 is apparently dominated by the interaction between the remnant and a giant molecular cloud.

scholarly journals A tale of two shocks in SN 2004dj

2013 ◽  
Vol 9 (S296) ◽  
pp. 108-111
Author(s):  
Alak Ray ◽  
Sayan Chakraborti ◽  
Naveen Yadav ◽  
Randall Smith ◽  
Poonam Chandra ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Mass Loss Rate ◽  
Circumstellar Matter ◽  
Published Data ◽  
Reverse Shock ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Field Amplification ◽  
Forward Shock ◽  
Red Supergiants

AbstractType IIP SNe constitute a major fraction of all core-collapse supernovae and arise from massive stars that end their lives close to Red Supergiants. The blastwave from the SN interacting with the progenitor's circumstellar matter produces a hot region bounded by a forward and a reverse shock from which most of the X-ray emission originates. Analysis of archival Chandra observations of SN 2004dj, one of the nearest supernovae since SN 1987A, together with published data from radio and optical bands determines the pre-explosion mass-loss rate, blastwave speed, electron acceleration and magnetic field amplification efficiencies. X-ray emission arises from both inverse Compton scattering by non-thermal electrons accelerated in the forward shock and from thermal emission from the supernova ejecta hit by the reverse shock. Determination of the properties of the radiating plasma based on the separation of thermal and non-thermal radiation differentiates different types of supernovae and their environments.

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