Dark matter is an invisible substance that makes up more than eighty percent of the matter content of the universe. We know of its existence due to its gravitational influence, being a key ingredient to understand everything from the large-scale evolution of the universe to the formation of galaxies like the Milky Way, of which we are part of . However, very little is known about its nature, which constitutes one of the greatest unsolved problems in contemporary physics. The fuzzy dark matter model has recently been studied as a promising candidate. In this model , it is postulated that dark
The development of the latest generation of Imaging Atmospheric Cherenkov Telescopes (IACTs) over recent decades has led to the discovery of new extreme astrophysical phenomena in the very-high-energy (VHE, E > 100 GeV) gamma-ray regime. Time-domain and multi-messenger astronomy are inevitably connected to the physics of transient VHE emitters, which show unexpected (and mostly unpredictable) flaring or exploding episodes at different timescales. These transients often share the physical processes responsible for the production of the gamma-ray emission, through cosmic-ray acceleration
The transient Swift J1727.8-162 is the latest member of the X-ray binary black hole family to be discovered. They are formed by a black hole and a low-mass star whose gas is stripped off and accreted to the black hole via an accretion disc. The high temperature of the accretion disc makes it shine in all energy bands up to X-rays, and is particularly bright during epochs known as outbursts. In this novel study, published just a few months after the discovery of the system, we present 20 epochs of optical spectroscopy obtained with the GTC-10.4m telescope. The spectra cover the main accretion