A large number of Ultra-Diffuse Galaxies (UDGs) has been detected over the past few years, both in clusters and in isolation. UDGs have stellar masses typical of dwarf galaxies but effective radii of Milky Way-sized objects, and their origin remains puzzling. Using hydrodynamical zoom-in simulations from the NIHAO project we show that UDGs form

True Seyfert 2 candidates are those Seyferts galaxies whose optical spectral do not show broad lines, nevertheless in the X-ray domain, they exhibit some characteristic behavior of Seyferts 1 such as lack of X-ray obscuration and/or short timescale variability. A true 2 candidate will be confirmed as a true Seyfert 2 if the lack of its broad line

Deep learning (DL) algorithms for morphological classification of galaxies have proven very successful, mimicking (or even improving) visual classifications. However, these algorithms rely on large training samples of labelled galaxies (typically thousands of them). A key question for using DL classifications in future Big Data surveys is how much

Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1 ×10 6 electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux

We obtained linear polarization photometry (J-band) and low-resolution spectroscopy (ZJ-bands) of TRAPPIST-1, which is a planetary system formed by an M8-type low-mass star and seven temperate, Earth-sized planets. The photopolarimetric monitoring campaign covered 6.5 h of continuous observations including one full transit of planet TRAPPIST-1d and

The origin of thick discs in galaxies remains shrouded in mystery. A variety of formation scenarios has been proposed. Here we aim to test one such scenario where the thick disc stars are proposed to be accreted from satellite galaxies. In this scenario, in at least some galaxies a fraction of thick disc stars would rotate in a retrograde way