The extreme ultraviolet and X-ray Sun in Time: High-energy evolutionary tracks of a solar-like star

A short review on theoretical implications of non-thermal emission (radio, extreme ultraviolet, high energy X-ray) from the intra-cluster medium is given. The origin of cluster radio halos and cluster radio relics is discussed within the framework of a network of processes producing a non-thermal electron population. Emphasis is given to the role of old, remnant, presently invisible relativistic plasma released by former radio galaxies.

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Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target: interaction of the radiation pulses with matter

Opto-Electronics Review ◽

10.1515/oere-2015-0023 ◽

2015 ◽

Vol 23 (2) ◽

Cited By ~ 2

Author(s):

A. Bartnik

Keyword(s):

Large Scale ◽

Extreme Ultraviolet ◽

High Energy ◽

High Energy Density ◽

Small Scale ◽

X Ray ◽

Target Interaction ◽

University Of Technology ◽

Photoionized Plasmas ◽

Intense Radiation

AbstractIn this work a review of investigations concerning interaction of intense extreme ultraviolet (EUV) and soft X-ray (SXR) pulses with matter is presented. The investigations were performed using laser-produced plasma (LPP) EUV/SXR sources based on a double stream gas puff target. The sources are equipped with dedicated collectors allowing for efficient focusing of the EUV/SXR radiation pulses. Intense radiation in a wide spectral range, as well as a quasi-monochromatic radiation can be produced. In the paper different kinds of LPP EUV/SXR sources developed in the Institute of Optoelectronics, Military University of Technology are described.Radiation intensities delivered by the sources are sufficient for different kinds of interaction experiments including EUV/SXR induced ablation, surface treatment, EUV fluorescence or photoionized plasma creation. A brief review of the main results concerning this kind of experiments performed by author of the paper are presented. However, since the LPP sources cannot compete with large scale X-ray sources like synchrotrons, free electron lasers or high energy density plasma sources, it was indicated that some investigations not requiring extreme irradiation parameters can be performed using the small scale installations. Some results, especially concerning low temperature photoionized plasmas are very unique and could be hardly obtained using the large facilities.

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RESIK and RHESSI observations of the 20 September 2002 flare

Astronomy and Astrophysics ◽

10.1051/0004-6361/202038434 ◽

2020 ◽

Vol 642 ◽

pp. A112

Author(s):

A. Kepa ◽

R. Falewicz ◽

M. Siarkowski ◽

M. Pietras

Keyword(s):

Extreme Ultraviolet ◽

High Energy ◽

Spectral Energy ◽

Data Sets ◽

X Rays ◽

Heliospheric Observatory ◽

X Ray ◽

Physical Conditions ◽

Synthetic Spectra ◽

Cross Calibration

Context. Soft X-ray spectra (3.33 Å–6.15 Å) from the RESIK instrument on CORONAS-F constitute a unique database for the study of the physical conditions of solar flare plasmas, enabling the calculation of differential emission measures. The two RESIK channels for the shortest wavelengths overlap with the lower end of the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) spectral energy range, which is located around 3 keV, making it possible to compare both data sets. Aims. We aim to compare observations from RESIK and RHESSI spectrometers and cross-correlate these instruments. Observations are compared with synthetic spectra calculated based on the results of one-dimensional hydrodynamical (1D-HD) modelling. The analysis was performed for the flare on 20 September 2002 (SOL2002-09-20T09:28). Methods. We estimated the geometry of the flaring loop, necessary for 1D-HD modelling, based on images from RHESSI and the Extreme-Ultraviolet Imaging Telescope aboard the Solar and Heliospheric Observatory. The distribution of non-thermal electrons (NTEs) was determined from RHESSI spectra. The 1D-HD model assumes that non-thermal electrons with a power-law spectrum were injected at the apex of the flaring loop. The NTEs then heat and evaporate the chromosphere, filling the loop with hot and dense plasma radiating in soft X-rays. The total energy of electrons was constrained by comparing observed and calculated fluxes from Geostationary Operational Environmental Satellite 1–8 Å data. We determined the temperature and density at every point of the flaring loop throughout the evolution of the flare, calculating the resulting X-ray spectra. Results. The synthetic spectra calculated based on the results of hydrodynamic modelling for the 20 September 2002 flare are consistent within a factor of two with the observed RESIK spectra during most of the duration of the flare. This discrepancy factor is probably related to the uncertainty on the cross-calibration between RESIK and RHESSI instruments.

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High energy density plasmas produced by x-ray and extreme ultraviolet lasers

10.1117/12.2023232 ◽

2013 ◽

Cited By ~ 2

Author(s):

Andrew K. Rossall ◽

Valentin Aslanyan ◽

Greg J. Tallents

Keyword(s):

Energy Density ◽

Extreme Ultraviolet ◽

High Energy ◽

High Energy Density ◽

X Ray ◽

Ultraviolet Lasers ◽

Extreme Ultraviolet Lasers ◽

High Energy Density Plasmas

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Magnetic activity, high-energy radiation and variability: from young solar analogs to low-mass objects

Proceedings of the International Astronomical Union ◽

10.1017/s174392130999295x ◽

2009 ◽

Vol 5 (S264) ◽

pp. 375-384

Author(s):

Manuel Güdel

Keyword(s):

Extreme Ultraviolet ◽

High Energy ◽

Magnetic Activity ◽

Energy Output ◽

Stellar Winds ◽

High Energy Radiation ◽

X Ray ◽

Cool Stars ◽

Low Mass ◽

Solar Analogs

AbstractMagnetic activity on cool stars expresses itself in a bewildering variety of radiative and particle output originating from magnetic regions between the photosphere and the corona. Given its origin in evolving magnetic fields, most of this output is variable in time. Radiation in the ultraviolet, the extreme ultraviolet, and the X-ray ranges are important for heating and ionizing upper planetary atmospheres and thus driving atmospheric evaporation. Additionally, stellar winds interact with the upper atmospheres and may lead to further erosion. The stellar high-energy output is therefore a prime factor in determining habitability of planets. We summarize our knowledge of magnetic activity in young solar analogs and lower-mass stars and show how the stellar output changes on evolutionary timescales.

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The Kepler-11 system: evolution of the stellar high-energy emission and initial planetary atmospheric mass fractions

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936581 ◽

2019 ◽

Vol 632 ◽

pp. A65 ◽

Cited By ~ 6

Author(s):

D. Kubyshkina ◽

L. Fossati ◽

A. J. Mustill ◽

P. E. Cubillos ◽

M. B. Davies ◽

...

Keyword(s):

Mass Loss ◽

Extreme Ultraviolet ◽

High Energy ◽

X Ray ◽

System Parameters ◽

The Past ◽

Energy Emission ◽

Mass Fractions ◽

High Energy Emission ◽

Atmospheric Mass

The atmospheres of close-in planets are strongly influenced by mass loss driven by the high-energy (X-ray and extreme ultraviolet, EUV) irradiation of the host star, particularly during the early stages of evolution. We recently developed a framework to exploit this connection and enable us to recover the past evolution of the stellar high-energy emission from the present-day properties of its planets, if the latter retain some remnants of their primordial hydrogen-dominated atmospheres. Furthermore, the framework can also provide constraints on planetary initial atmospheric mass fractions. The constraints on the output parameters improve when more planets can be simultaneously analysed. This makes the Kepler-11 system, which hosts six planets with bulk densities between 0.66 and 2.45 g cm−3, an ideal target. Our results indicate that the star has likely evolved as a slow rotator (slower than 85% of the stars with similar masses), corresponding to a high-energy emission at 150 Myr of between 1 and 10 times that of the current Sun. We also constrain the initial atmospheric mass fractions for the planets, obtaining a lower limit of 4.1% for planet c, a range of 3.7–5.3% for planet d, a range of 11.1–14% for planet e, a range of 1–15.6% for planet f, and a range of 4.7–8.7% for planet g assuming a disc dispersal time of 1 Myr. For planet b, the range remains poorly constrained. Our framework also suggests slightly higher masses for planets b, c, and f than have been suggested based on transit timing variation measurements. We coupled our results with published planet atmosphere accretion models to obtain a temperature (at 0.25 AU, the location of planet f) and dispersal time of the protoplanetary disc of 550 K and 1 Myr, although these results may be affected by inconsistencies in the adopted system parameters. This work shows that our framework is capable of constraining important properties of planet formation models.

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Multiple Electron Acceleration Instances during a Series of Solar Microflares Observed Simultaneously at X-Rays and Microwaves

The Astrophysical Journal ◽

10.3847/1538-4357/ac2aa6 ◽

2021 ◽

Vol 922 (2) ◽

pp. 134

Author(s):

Marina Battaglia ◽

Rohit Sharma ◽

Yingjie Luo ◽

Bin Chen ◽

Sijie Yu ◽

...

Keyword(s):

Active Region ◽

Extreme Ultraviolet ◽

High Sensitivity ◽

Electron Acceleration ◽

High Energy ◽

Continuum Emission ◽

X Rays ◽

Very Large Array ◽

X Ray ◽

Flare Site

Abstract Even small solar flares can display a surprising level of complexity regarding their morphology and temporal evolution. Many of their properties, such as energy release and electron acceleration can be studied using highly complementary observations at X-ray and radio wavelengths. We present X-ray observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager and radio observations from the Karl G. Jansky Very Large Array (VLA) of a series of GOES A3.4–B1.6 class flares observed on 2013 April 23. The flares, as seen in X-ray and extreme ultraviolet, originated from multiple locations within active region NOAA 11726. A veritable zoo of different radio emissions between 1 GHz and 2 GHz was observed cotemporally with the X-ray flares. In addition to broadband continuum emission, broadband short-lived bursts and narrowband spikes, indicative of accelerated electrons, were observed. However, these sources were located up to 150″ away from the flaring X-ray sources but only some of these emissions could be explained as signatures of electrons that were accelerated near the main flare site. For other sources, no obvious magnetic connection to the main flare site could be found. These emissions likely originate from secondary acceleration sites triggered by the flare, but may be due to reconnection and acceleration completely unrelated to the cotemporally observed flare. Thanks to the extremely high sensitivity of the VLA, not achieved with current X-ray instrumentation, it is shown that particle acceleration happens frequently and at multiple locations within a flaring active region.

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Radio and X-ray Observations of Short-lived Episodes of Electron Acceleration in a Solar Microflare

10.5194/egusphere-egu21-14293 ◽

2021 ◽

Author(s):

Rohit Sharma ◽

Marina Battaglia ◽

Yingjie Luo ◽

Bin Chen ◽

Sijie Yu

Keyword(s):

Extreme Ultraviolet ◽

Magnetic Energy ◽

Electron Acceleration ◽

High Energy ◽

Nonthermal Electron ◽

X Rays ◽

Solar Dynamics Observatory ◽

Lower Corona ◽

X Ray ◽

Multi Wavelength

<p>Solar flares release enormous magnetic energy into the corona, producing the heating of ambient plasma and acceleration of particles. The flaring process is complex and often shows multiple spatially separated temporal individual episodes of energy releases, which can be hard to resolve based on the instrument capability. We analysed the multi-wavelength imaging and spectroscopy observations of multiple electron acceleration episodes during a GOES B1.7-class two-ribbon flare observed simultaneously with the Karl G. Jansky Very Large Array (VLA) at 1--2 GHz, the Reuven Ramatay High Energy Solar Spectroscopic Imager (RHESSI) in X-rays, and the Solar Dynamics Observatory in extreme ultraviolet (EUV).<br>We observed a total of six radio bursts. First three bursts were co-temporal, but not co-spatial nonthermal X-ray source and represent multiple electron acceleration episodes. We model the radio spectra by optically thick gyrosynchrotron emission and estimate the magnetic field strength and nonthermal electron spectral parameters in each acceleration episode. We note that the nonthermal parameters derived from X-rays differ considerably from the nonthermal parameters inferred from the radio and originates in the lower corona. Although co-temporal, our multi-wavelength analysis shows that different electron populations produce multiple acceleration episodes in radio and X-rays wavelengths.&#160;</p>

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X-exoplanets: an X-ray and EUV database for exoplanets

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309993152 ◽

2009 ◽

Vol 5 (S264) ◽

pp. 478-483 ◽

Cited By ~ 1

Author(s):

J. Sanz-Forcada ◽

D. García-Álvarez ◽

A. Velasco ◽

E. Solano ◽

I. Ribas ◽

...

Keyword(s):

Main Sequence ◽

Extreme Ultraviolet ◽

High Energy ◽

Atmospheric Composition ◽

X Rays ◽

High Energy Radiation ◽

X Ray ◽

Euv Emission ◽

Synthetic Spectra ◽

Parent Star

AbstractExtreme Ultraviolet (EUV) and X-ray emission is of great importance in several phenomena related to the formation of planetary systems and the atmospheres of planets. The atmospheric composition, and the mass of an exoplanet, are partly dependent on the X-ray and EUV radiation received during the first stages of formation and even during main sequence of the star. Biological life developing on exoplanets would depend severely on the high energy radiation arriving from its parent star.Here we present a database of the X-ray and EUV emission of all the stars currently known to host exoplanets. The archive is public and accessible through the Spanish Virtual Observatory (SVO). The database gives the user the option to download observed X-rays and EUV spectra. Synthetic spectra covering the spectral range 1–912 Å are also available (present day telescopes do not give access to the EUV range at λ > 180 Å). These spectra are created using coronal models after fitting observed spectra.

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