O ne of the key challenges in astronomy is to measure accurate distances to celestial objects. Knowing distances is crucial since it allows us to measure physical properties such as size, mass and luminosity. Since we can’t go out and use a tape-measure, a range of different approaches have been developed. Many of these approaches rely on using “standard candles”. Standard candles are objects (for example stars or supernovae) for which we know their intrinsic ”true” brightness. Once we know this, then their observed brightness compared to their intrinsic brightness gives us a distance to the
WISEA J181006.18-101000.5 (WISE1810) is the nearest metal-poor ultracool dwarf to the Sun. It has a low effective temperature and has been classified as an extreme early-T subdwarf. However, methane--the characteristic molecule of the spectral class T--was not detected in the previous low-resolution spectrum. Constraining the metallicity--the abundance of elements heavier than helium-- of these cold objects has been a challenge. Using the 10.4 m Gran Telescopio Canarias, the largest optical-infrared telescope in the world, we collected a high-quality near-infrared intermediate-resolution
Recent observational studies suggest that feedback from active galactic nuclei (AGNs)—the energetic centres powered by supermassive black holes—may play an important role in the formation and evolution of dwarf galaxies, contrary to the standard thought. We investigated this using two sets of 12 cosmological magnetohydrodynamic simulations of the formation of dwarf galaxies: one set using a version of the AURIGA galaxy formation physics model including AGN feedback and a parallel set with AGN feedback turned off. Our results reveal that AGNs can suppress the star formation (SF) of dwarf