A central question regarding ultra-diffuse galaxies (UDGs) is whether they are in a separate category from low-surface-brightness (LSB) galaxies, or just their natural continuation toward low stellar masses. In this Letter, we show that the rotation curve of the gas rich UDG AGC 242019 is well fit by a dark matter halo with an inner slope that asymptotes to ~-0.54, and that such a fit provides a concentration parameter that matches theoretical expectations. This finding, together with previous works in which shallow inner profiles are derived for UDGs, shows that the structural properties of these galaxies are like other observed LSBs. UDGs show slowly rising rotation curves and this favors formation scenarios in which internal processes, such as supernova-driven gas outflows, are acting to modify UDG profiles.
It may interest you
Scientists and engineers from the institutions making up the consortium for building the EST have met in La Palma to evaluate the end of the preparatory phase. The European Solar Telescope (EST) project has finished the preliminary design phase of the sistemas and subsystems for what will be the largest solar telescope in Europe, in the framework of the european project PRE-EST. With its primary mirror of 4.2 metres diameter, the EST will be a unique driving force for solar research in Europe. It is planned to start construction in 2024, in the Roque de los Muchachos Observatory (La PalmaAdvertised on
The amount and complexity of data delivered by modern galaxy surveys has been steadily increasing over the past years. New facilities will soon provide imaging and spectra of hundreds of millions of galaxies. Extracting coherent scientific information from these large and multi-modal data sets remains an open issue for the community and data-driven approaches such as deep learning have rapidly emerged as a potentially powerful solution to some long lasting challenges. This enthusiasm is reflected in an unprecedented exponential growth of publications using neural networks, which have goneAdvertised on
A team led by researchers from the Instituto de Astrofísica de Canarias (IAC) and the National Astronomical Observatory of Japan (NAOJ) has made, with the Gran Telescopio Canarias (GTC or Grantecan) and the Subaru telescope, the largest and deepest follow-up to date of a black hole collision previously detected in gravitational waves. The observations showed no optical signal in the direction of the phenomenon, which means that if this black hole merger emitted any light at all, it was fainter than the detection limit of these two telescopes and their instruments. This result imposes anAdvertised on