We find that the mass ratio q in quiescent black hole (BH) X-ray transients is tightly correlated with the ratio of the double-peak separation (DP) to the full width half maximum (FWHM) of the H α emission line, {log}q=-6.88-23.2\quad {log}({DP}/{FWHM}). This correlation is explained through the efficient truncation of the outer disk radius by the

The interpretation of local helioseismic measurements of sunspots has long been a challenge, since waves propagating through sunspots are potentially affected by both mode conversion and changes in the thermal structure of the spots. We carry out numerical simulations of wave propagation through a variety of models which alternately isolate either

Context. During February-March 2014, the MAGIC telescopes observed the high-frequency peaked BL Lac 1ES 1011+496 (z = 0.212) in flaring state at very-high energy (VHE, E> 100 GeV). The flux reached a level of more than ten times higher than any previously recorded flaring state of the source. Aims: To describe the characteristics of the flare

We report on an exceptional large-scale coronal pseudostreamer/cavity system in the southern polar region of the solar corona that was visible for approximately a year starting in February 2014. It is unusual to see such a large closed-field structure embedded within the open polar coronal hole. We investigate this structure to document its

Discovering the nature of Dark Matter (DM) is one of the fundamental challenges of the modern physics. Indirect searches of DM are devoted to look for non-gravitational signals of its presence in the highly DM dominated cosmic regions. Within the weakly interacting massive particles (WIMPs) scenario, we expect very high energy (VHE) gamma-ray

The search for detection of γ-rays from distant AGNs by Imaging Atmospheric Cherenkov Telescopes (IACTs) is challenging at high redshifts, not only because of lower flux due to the distance of the source, but also due to the consequent absorption of γ-rays by the extragalactic background light (EBL). Before the MAGIC discoveries reported in this