scholarly journals Slow motion pulsar wind nebulae

2021 ◽  
Vol 2103 (1) ◽  
pp. 012020
Author(s):  
K P Levenfish ◽  
G A Ponomaryov ◽  
A E Petrov ◽  
A M Bykov ◽  
A M Krassilchtchikov
Keyword(s):  
Time Scales ◽  
Relative Motion ◽  
Slow Motion ◽  
High Energy ◽  
Pulsar Wind Nebulae ◽  
Extra Time ◽  
X Ray ◽  
Energy Emission ◽  
Pulsar Wind ◽  
High Energy Emission

Abstract We show that even the slow (subsonic) motion of pulsar wind nebulae (PWNe) relative to an ambient matter has a significant impact on their observables. The motion changes the appearance of nebulae on X-ray images, comparing to what would be observed for a nebula at rest. Accounting for the relative motion is necessary to avoid misinterpretation of the structure of the nebulae when analyzing their X-ray morphology. The motion also introduces some extra time scales in variability of non-thermal high-energy emission of PWNe and allows to reproduce a number of their structures that are not explained by stationary nebula models.

scholarly journals EUV irradiation of exoplanet atmospheres occurs on Gyr time-scales

2020 ◽  
Vol 501 (1) ◽  
pp. L28-L32
Author(s):  
George W King ◽  
Peter J Wheatley
Keyword(s):  
Mass Loss ◽  
Time Scales ◽  
High Energy ◽  
Planetary Atmospheres ◽  
X Rays ◽  
X Ray ◽  
Atmospheric Escape ◽  
Euv Emission ◽  
Energy Emission ◽  
High Energy Emission

ABSTRACT Exoplanet atmospheres are known to be vulnerable to mass-loss through irradiation by stellar X-ray and extreme-ultraviolet (EUV) emission. We investigate how this high-energy irradiation varies with time by combining an empirical relation describing stellar X-ray emission with a second relation describing the ratio of solar X-ray to EUV emission. In contrast to assumptions commonly made when modelling atmospheric escape, we find that the decline in stellar EUV emission is much slower than in X-rays, and that the total EUV irradiation of planetary atmospheres is dominated by emission after the saturated phase of high-energy emission (which lasts around 100 Myr after the formation of the star). The EUV spectrum also becomes much softer during this slow decline. Furthermore, we find that the total combined X-ray and EUV emission of stars occurs mostly after the saturated phase. Our results suggest that models of atmospheric escape that focus on the saturated phase of high-energy emission are oversimplified, and when considering the evolution of planetary atmospheres it is necessary to follow EUV-driven escape on Gyr time-scales. This may make it more difficult to use stellar age to separate the effects of photoevaporation and core-powered mass-loss when considering the origin of the planet radius valley.

scholarly journals ON THE INTERACTION OF JETS WITH STELLAR WINDS IN MASSIVE X–RAY BINARIES

2010 ◽  
Vol 19 (06) ◽  
pp. 791-796
Author(s):  
MANEL PERUCHO ◽  
VALENTÍ BOSCH-RAMON ◽  
DMITRY KHANGULYAN
Keyword(s):  
Stellar Wind ◽  
Binary Star ◽  
Three Dimensional ◽  
High Energy ◽  
X Ray ◽  
Energy Emission ◽  
Injection Power ◽  
Radio Band ◽  
High Energy Emission ◽  
X Ray Binaries

We present the first three-dimensional simulations of the evolution of a microquasar jet inside the binary star system. The aim is to study the interaction of these jets with the stellar wind from a massive companion and the possible locations of high-energy emission sites. We have simulated two jets with different injection power in order to give a hint on the minimum power required for the jet to escape the system and become visible in larger scales. In the setup, we include a massive star wind filling the grid through which the jet evolves. We show that jets should have powers of the order of 1037 erg s-1 or more in order not to be destroyed by the stellar wind. The jet–wind interaction results in regions in which high-energy emission could be produced. These results imply the possible existence of a population of X–ray binaries undetected in the radio band due to jet disruption inside the region dominated by the stellar wind.

scholarly journals Jet-like structures from PSR J1135–6055

2020 ◽  
Vol 644 ◽  
pp. L4
Author(s):  
P. Bordas ◽  
X. Zhang
Keyword(s):  
High Energy ◽  
Bow Shock ◽  
Morphological Properties ◽  
Physical Origin ◽  
Pulsar Wind Nebulae ◽  
Jet Formation ◽  
X Ray ◽  
Pulsar Wind ◽  
Alternative Scenarios ◽  
High Energy Particles

Pulsar wind nebulae (PWNe) produced from supersonic runaway pulsars can render extended X-ray structures in the form of tails and prominent jets. In this Letter, we report on the analysis of ∼130 ks observations of the PWN around PSR J1135–6055 that were obtained with the Chandra satellite. The system displays bipolar jet-like structures of uncertain origin, a compact nebula around the pulsar likely formed by the bow shock ahead of it, and a trailing tail produced by the pulsar fast proper motion. The spectral and morphological properties of these structures reveal strong similarities with the PWNe in other runaway pulsars, such as PSR J1509–5850 and Geminga. We discuss their physical origin considering both canonical PWN and jet formation models as well as alternative scenarios that can also yield extended jet-like features following the escape of high-energy particles into the ambient magnetic field.

scholarly journals PULSAR WIND NEBULAE MODELING

2014 ◽  
Vol 28 ◽  
pp. 1460162 ◽  
Author(s):  
NICCOLÒ BUCCIANTINI
Keyword(s):  
High Resolution ◽  
High Energy ◽  
Clear Understanding ◽  
Strong Impact ◽  
Pulsar Magnetosphere ◽  
Pulsar Wind Nebulae ◽  
X Ray ◽  
X Ray Imaging ◽  
Dynamical Properties ◽  
Pulsar Wind

Pulsar Wind Nebulae (PWNe) are ideal astrophysical laboratories where high energy relativistic phenomena can be investigated. They are close, well resolved in our observations, and the knowledge derived in their study has a strong impact in many other fields, from AGNs to GRBs. Yet there are still unresolved issues, that prevent us from a full clear understanding of these objects. The lucky combination of high resolution X-ray imaging and numerical codes to handle the outflow and dynamical properties of relativistic MHD, has opened a new avenue of investigation that has lead to interesting progresses in the last years. Despite all of this, we do not understand yet how particles are accelerated, and the functioning of the pulsar wind and pulsar magnetosphere, that power PWNe. I will review what is now commonly known as the MHD paradigm, and in particular I will focus on various approaches that have been and are currently used to model these systems. For each I will highlight its advantages, limitations, and degree of applicability.

scholarly journals PSR B0656+14: Combined Optical, X-ray & EUV Studies

2000 ◽  
Vol 177 ◽  
pp. 299-300
Author(s):  
Aaron Golden ◽  
Andy Shearer ◽  
Jerry Edelstein
Keyword(s):  
High Energy ◽  
Archival Data ◽  
Polar Cap ◽  
Optical Photometry ◽  
X Ray ◽  
Energy Emission ◽  
High Energy Emission

AbstractPSR B0656+14’s high energy emission is consistent with that of combined magnetospheric and thermal (surface & polar cap) emission. Uncertainties with the radio-derived distance and X-ray instrumentation sensitivities complicate a definitive thermal characterisation however. A re-analysis of combined ROSAT/EUVE archival data in conjunction with integrated & phase-resolved optical photometry is shown to constrain this characterisation.

scholarly journals X-ray Variability of Blazars

2002 ◽  
Vol 19 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Elena Pian
Keyword(s):  
Energy Range ◽  
High Energy ◽  
Space Missions ◽  
Present Review ◽  
Wide Energy Range ◽  
Spectral Variability ◽  
X Ray ◽  
Energy Emission ◽  
Wide Energy ◽  
High Energy Emission

AbstractCritical progress in our understanding of high energy emission from AGN has been determined in the last 10 years by X-ray monitoring campaigns with many space missions, notably ROSAT, ASCA, RXTE, BeppoSAX, and XMM, often in conjunction with observations at other frequencies. The emphasis of the present review is on recent findings about X-ray variability of blazars. Among AGN, these exhibit the largest amplitude variations of the X-ray emission, often well correlated with variations at higher energies (GeV and TeV radiation). The accurate sampling of the X-ray spectra over more than three decades in energy, made possible by the wide energy range of BeppoSAX, has also shown strong spectral variability in blazar active states, suggesting extreme electron energies and leading to the identification of a class of ‘extreme synchrotron’ sources.

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