Related papers: Young stellar objects from soft to hard X-rays
The X-ray emission from the Sun reveals a very dynamic hot atmosphere, the corona, which is characterized by a complex morphology and broad range of timescales of variability and spatial structuring. The solar magnetic fields play a…
Cool stars like the Sun harbor convection zones capable of producing substantial surface magnetic fields leading to stellar magnetic activity. The influence of stellar parameters like rotation, radius, and age on cool-star magnetism, and…
Chandra and XMM-Newton have surveyed several nearby star forming regions and have greatly advanced our knowledge of X-ray emission from Young Stellar Objects (YSOs). After briefly reviewing it I discuss the advancements in this research…
A young neutron star with large spin-down power is expected to be closely surrounded by an e+/- pair plasma maintained by the conversion of gamma-rays associated with the star's polar-cap and/or outer-gap accelerators. Cyclotron-resonance…
Stellar magnetic activity provides substantial information on the magnetic dynamo and the coronal heating process. We present a catalog of X-ray activity for about 6000 stars, based on the $Chandra$ and $Gaia$ DR2 data. We also classified…
Young O stars are strong, hard, and variable X-ray sources, properties which strongly affect their circumstellar and galactic environments. After ~1 Myr, these stars settle down to become steady sources of soft X-rays. I use high-resolution…
High resolution X-ray spectra of very young massive stars opened a new chapter in the diagnostics and understanding of the properties of stellar wind plasmas. Observations of several very young early type stars in the Orion Trapezium…
Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…
Observations indicate that magnetic fields in rapidly rotating stars are very strong, on both small and large scales. What is the nature of the resulting corona? Here we seek to shed some light on this question. We use the results of an…
X-ray and ultraviolet (XUV) emission from young stars plays a critical role in shaping the evolution of planetary atmospheres and the conditions for habitability. To assess the long-term impact of high-energy stellar radiation, it is…
Our understanding of the structure and dynamics of stellar coronae has changed dramatically with the availability of surface maps of both star spots and also magnetic field vectors. Magnetic field extrapolations from these surface maps…
Since the '80s the \textit{Einstein} observatory has shown the Young Stellar Objects (YSOs), emit X-rays with luminosities, in the 0.3--8 keV bandpass, up to $\rm 10^3$--$\rm 10^4$ times than the Sun and that the X-ray emission is highly…
The powerful radiative winds of hot stars with strong magnetic fields are magnetically confined into large, corotating magnetospheres, which exert important influences on stellar evolution via rotational spindown and mass-loss quenching.…
We present a survey of X-ray emission from young stars in the Sword of Orion star-formation region using XMM-Newton's EPIC detectors. We find over 850 X-ray sources, of which more than 700 have near-infrared counterparts consistent with…
Studies of element abundances in stars are of fundamental interest for their impact in a wide astrophysical context, from our understanding of galactic chemistry and its evolution, to their effect on models of stellar interiors, to the…
Recent X-ray observations have had a major impact on topics ranging from protostars to cosmology. They have also drawn attention to important and general physical processes that currently limit our understanding of thermal and nonthermal…
We present here a phenomenological solid quark star pulsar model to interpret the observed thermal X-ray emission of isolated pulsars. The heat capacity for solid quark stars was found to be quite small, so that the residual internal…
Particles are accelerated to very high, non-thermal energies during explosive energy-release phenomena in space, solar, and astrophysical plasma environments. In the case of solar flares, it has been established that magnetic reconnection…
Low-mass, pre-main sequence stars possess intense high-energy radiation fields as a result of their strong stellar magnetic activity. This stellar UV and X-ray radiation may have a profound impact on the lifetimes of protoplanetary disks.…
This summary talk aims at highlighting some of the remaining open issues regarding the physics of the magnetospheric accretion/ejection process in young stellar objects (YSOs). It lists a number of questions related to YSOs magnetic fields…