scholarly journals Temporal and spatial variation of synchrotron X-ray stripes in Tycho’s supernova remnant

2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Masamune Matsuda ◽  
Takaaki Tanaka ◽  
Hiroyuki Uchida ◽  
Yuki Amano ◽  
Takeshi Go Tsuru
Keyword(s):  
Surface Brightness ◽  
Supernova Remnant ◽  
Time Variability ◽  
X Rays ◽  
Temporal And Spatial Variation ◽  
Proton Acceleration ◽  
X Ray ◽  
Temporal And Spatial ◽  
Imaging And Spectroscopy ◽  
The Magnetic Field

Abstract The synchrotron X-ray “stripes” discovered in Tycho’s supernova remnant (SNR) have been attracting attention as they may be evidence for proton acceleration up to PeV. We analyzed Chandra data taken in 2003, 2007, 2009, and 2015 for imaging and spectroscopy of the stripes in the southwestern region of the SNR. Comparing images obtained at different epochs, we find that time variability of synchrotron X-rays is not limited to two structures previously reported but is more common in the region. Spectral analysis of nine bright stripes reveals not only their time variabilities but also a strong anti-correlation between the surface brightness and photon indices. The spectra of the nine stripes have photon indices of Γ = 2.1–2.6 and are significantly harder than those of the outer rim of the SNR in the same region with Γ = 2.7–2.9. Based on these findings, we indicate that the magnetic field is substantially amplified, and suggest that particle acceleration through a stochastic process may be at work in the stripes.

scholarly journals Thermal and non-thermal connection in radio mini-halos

2018 ◽  
Vol 14 (S342) ◽  
pp. 137-140
Author(s):  
A. Ignesti ◽  
G. Brunetti ◽  
M. Gitti ◽  
S. Giacintucci
Keyword(s):  
Magnetic Field ◽  
Surface Brightness ◽  
X Rays ◽  
X Ray ◽  
Point Analysis ◽  
Spectrum Radio ◽  
Point To Point ◽  
The Magnetic Field ◽  
Relativistic Particles ◽  
Open Issues

AbstractSeveral cool-core clusters are known to host a radio mini-halo, a diffuse, steep-spectrum radio source located in their cores, thus probing the presence of non-thermal components as magnetic field and relativistic particles on scales not directly influenced by the central AGN. The nature of the mechanism that produces a population of radio-emitting relativistic particles on the scale of hundreds of kiloparsecs is still unclear. At the same time, it is still debated if the central AGN may play a role in the formation of mini-halos by providing the seed of the relativistic particles. We aim to investigate these open issues by studying the connection between thermal and non-thermal components of the intra-cluster medium. We performed a point-to-point analysis of the radio and the X-ray surface brightness of a compilation of mini-halos. We find that mini-halos have super-linear scalings between radio and X-rays, with radio brightness declining more steeply than the X-ray brightness. This trend is opposite to that generally observed in giant radio halos, thus marking a possible difference in the physics of the two radio sources. Finally, using the scalings between radio and X-rays and assuming a hadronic origin of mini-halos we derive constraints on the magnetic field in the core of the hosting clusters.

scholarly journals X-ray Interferometry

2001 ◽  
Vol 205 ◽  
pp. 457-462
Author(s):  
Webster Cash
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Surface Brightness ◽  
High Surface ◽  
X Rays ◽  
High Surface Brightness ◽  
X Ray

X-rays have tremendous potential for imaging at the highest angular resulution. The high surface brightness of many x-ray sources will reveal angular scales heretofore thought unreachable. The short wavelengths make instrumentation compact and baselines short. We discuss how practical x-ray interferometers can be built for astronomy using existing technology. We describe the Maxim Pathfinder and Maxim missions which will achieve 100 and 0.1 micro-arcsecond imaging respectively. The science to be tackled with resolution of up to one million times that of HST will be outlined, with emphasis on eventually imaging the event horizon of a black hole.

First X-Ray Microprobe and Microspectroscopy Results From The Gsecars Sector At The Advanced Photon Source

1997 ◽  
Vol 3 (S2) ◽  
pp. 905-906
Author(s):  
Mark L. Rivers ◽  
Stephen R. Sutton ◽  
Peter Eng ◽  
Matthew Newville
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Third Generation ◽  
X Rays ◽  
Environmental Sciences ◽  
X Ray ◽  
State Determination ◽  
X Ray Absorption ◽  
The Magnetic Field ◽  
Photon Source

The Advanced Photon Source (APS) at Argonne National Laboratory is a third-generation synchrotron x-ray source, optimized for producing x-rays from undulators. Such undulator sources provide extremely bright, quasi-monochromatic radiation which is ideal for an x-ray microprobe. Such microprobes can be used for trace element quantification with x-ray fluorescence, or for chemical state determination with x-ray absorption spectroscopy. The GeoSoilEnviroCARS (GSECARS) sector at the APS is building an x-ray microprobe for research in earth, planetary, soil and environmental sciences.The GSECARS undulator source is a standard APS Undulator “A” which is a 3.3 cm period device with 72 periods. The energies of the undulator peaks can be varied by adjusting the gap, and hence the magnetic field of the undulator. The energy of the first harmonic can be varied in this way from approximately 3.1 keV to 14 keV. A measured undulator spectrum is shown in Figure 1.

scholarly journals Wide-field Cameras for GRB Observations in X-rays and EUV

1995 ◽  
Vol 151 ◽  
pp. 431-434
Author(s):  
Eugene Moskalenko
Keyword(s):  
Time Scale ◽  
Field Of View ◽  
Time Variability ◽  
Wide Field ◽  
Main Task ◽  
X Rays ◽  
Interstellar Absorption ◽  
X Ray ◽  
Instrumental Approaches ◽  
Stationary Sources

Recent observations of the ASCA satellite resulted in the first identification of a GB source (Murakami et al. 1994). This success confirmed the importance of simultaneous observations in different wavelength bands for GB studies. Besides the ASCA results, there were several observations of GBs in X-ray band with the Ginga (Yoshida et al,.1989), V 78/1 (Laros et al. 1984) and other satellites. It became clear that GBs emit 4 - 8% of their energy in the 2 - 10 keV range. The main task now is to have an equipment which will be able to monitor the sky in X-rays in a mode similar to that of GRO observations, i.e. the telescope should have an all-sky field-of-view (FoV) and should work continuously.A telescope with these features but operating at soft X-ray energies may directly determine the GB distance scale, due to interstellar absorption of the photons with energies less than 2 keV, as was pointed out first by Schaefer (1993). Flaring sources similar to GBs in time scale may be found also in the EUV (hundreds of angstroms) with the help of very wide-field cameras. Of course each such device - in X-ray, soft X-ray and EUV bands - will discover many transient objects, flaring events, will study time variability of bright “stationary” sources etc. In this paper we describe several instrumental approaches in these fields.

The X-ray surface brightness of Kepler's supernova remnant

1983 ◽  
Vol 264 ◽  
pp. 196 ◽  
Author(s):  
R. L. White ◽  
K. S. Long
Keyword(s):  
Surface Brightness ◽  
Supernova Remnant ◽  
X Ray

scholarly journals Numerically investigating the morphology of the supernova remnant SN 1006 in the ambient medium with a density discontinuity

2019 ◽  
Vol 491 (2) ◽  
pp. 2460-2464 ◽  
Author(s):  
Jun Fang ◽  
Jingwen Yan ◽  
Lu Wen ◽  
Chunyan Lu ◽  
Huan Yu
Keyword(s):  
Supernova Remnant ◽  
Ambient Medium ◽  
X Rays ◽  
X Ray ◽  
North West ◽  
Density Discontinuity ◽  
North East ◽  
The North ◽  
South West ◽  
Type Ia

ABSTRACT Multiband observations on the Type Ia supernova remnant SN 1006 indicate peculiar properties in its morphologies of emission in the radio, optical, and X-ray bands. In the hard X-rays, the remnant is bilateral with two opposite bright limbs with prominent protrusions. Moreover, a filament has been detected at the radio, optical, and soft X-ray wavelengths. The reason for these peculiar features in the morphologies of the remnant is investigated using 3D HD simulations. With the assumption that the supernova ejecta are evolved in the ambient medium with a density discontinuity, the radius of the remnant’s boundary is smaller in the tenuous medium, and the shell consists of two hemispheres with different radii. Along particular line of sights, protrusions appear on the periphery of the remnants since the emission from the edge of the hemisphere with a larger radius is located outside that from the shell of the small hemisphere. Furthermore, the north-west filament of SN 1006 arises as a result of the intersection of the line of sight and the shocked material near the edges of the two hemispheres. It can be concluded that the protrusions on the north-east and south-west limbs and the north-west filament in the morphologies of SN 1006 can be reproduced as the remnants interacting with the medium with a density discontinuity.

scholarly journals XMM-Newton and Fermi/LAT view on the supernova remnant 3C434.1

2019 ◽  
Vol 631 ◽  
pp. A179
Author(s):  
V. Doroshenko ◽  
D. Malyshev ◽  
G. Pühlhofer ◽  
B. Dincel ◽  
M. Sasaki ◽  
...  
Keyword(s):  
Power Law ◽  
Supernova Remnant ◽  
X Rays ◽  
Significant Excess ◽  
X Ray ◽  
Thermal Origin

We report on XMM-Newton observations of the supernova remnant (SNR) 3C434.1 (G94.0+1.0), the first in X-rays since the ROSAT era. Our analysis confirms the thermal origin of the observed extended X-ray emission, whose morphology appears more complex than previously reported. In particular, part of the shell shows a significantly harder spectrum which is consistent with a power law, and it is, therefore, likely of non-thermal origin. Motivated by these finding, we revisited the GeV observations of the field taken with the Fermi observatory. A significant excess associated with the remnant was detected, which is likely associated with non-thermal X-ray emission from part of the shell. The analysis of the Fermi data resulted in the serendipity discovery of GeV emission from the nearby SNR G093.7-00.2. Finally, we searched for a possible compact remnants within the shell, however, no obvious candidates could be identified due to the fairly large positional uncertainties.

scholarly journals New composite supernova remnant toward HESS J1844-030?

2019 ◽  
Vol 626 ◽  
pp. A65
Author(s):  
A. Petriella
Keyword(s):  
Supernova Remnant ◽  
High Energy ◽  
Radio Continuum ◽  
Pressure Balance ◽  
High Energy Radiation ◽  
X Ray ◽  
Galactic Source ◽  
Very High Energy ◽  
The Magnetic Field ◽  
Very High

Aims. HESS J1844-030 is a newly confirmed TeV source in the direction of the X-ray pulsar wind nebula (PWN) candidate G29.4+0.1 and the complex radio source G29.37+0.1, which is likely formed by the superposition of a background radio galaxy and a Galactic supernova remnant (SNR). Many scenarios have been proposed to explain the origin of HESS J1844-030, based on several sources that are capable of producing very high energy radiation. We investigate the possible connection between the SNR, the PWN G29.4+0.1, and HESS J1844-030 to shed light on the astrophysical origin of the TeV emission. Methods. We performed an imaging and spectral study of the X-ray emission from the PWN G29.4+0.1 using archival observations obtained with the Chandra and XMM-Newton telescopes. Public radio continuum and HI data were used to derive distance constraints for the SNR that is linked to G29.37+0.1 and to investigate the interstellar medium where it is expanding. We applied a simple model of the evolution of a PWN inside an SNR to analyze the association between G29.4+0.1 and the radio emission from G29.37+0.1. We compared the spectral properties of the system with the population of TeV PWNe to investigate if HESS J1844-030 is the very high energy counterpart of the X-ray PWN G29.4+0.1. Results. Based on the morphology and spectral behavior in the X-ray band, we conclude that G29.4+0.1 is a PWN and that a point source embedded on it is the powering pulsar. The HI data revealed that the SNR linked to G29.37+0.1 is a Galactic source at 6.5 kpc and expanding in a nonuniform medium. From the analysis of the pulsar motion and the pressure balance at the boundary of X-ray emission, we conclude that G29.4+0.1 could be a PWN that is located inside its host remnant, forming a new composite SNR. Based on the magnetic field of the PWN obtained from the X-ray luminosity, we found that the population of electrons producing synchrotron radiation in the keV band can also produce IC photons in the TeV band. This suggests that HESS J1844-030 could be the very high energy counterpart of G29.4+0.1.

scholarly journals On Special Features of Non-Thermal Solar X Radiation above 10 keV

1972 ◽  
Vol 14 ◽  
pp. 761-762
Author(s):  
G. Elwert ◽  
E. Haug
Keyword(s):  
Magnetic Field ◽  
Angular Distribution ◽  
Power Law ◽  
Impulsive Phase ◽  
X Rays ◽  
Energetic Electrons ◽  
X Ray ◽  
Preferred Direction ◽  
Field Lines ◽  
The Magnetic Field

The polarization and angular distribution of solar hard X radiation above 10 keV was calculated under the assumption that the X rays originate as bremsstrahlung from energetic electrons moving in a preferred direction. The source electrons are supposed to have a power-law spectrum. These conditions are to be expected in the impulsive phase of an X-ray burst. The spiral orbits of the electrons around the magnetic field lines are taken into account.

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