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The ZOMG view on the radial acceleration relation

Let's start the new year with some good news! While diving in the sea of applications for my first post-doc, I managed to submit a nice letter that analyses for the first time what the LCDM model has to say about the radial acceleration relation (RAR) in the regime of dwarf galaxies. The standard cosmological model predicts the satellites to lie on the same RAR as their host galaxies, although with a much larger scatter. In the letter I also analyse how single objects evolve along the RAR and what are the physical mechanisms at play. In the process, I devised a simple test that could allow us to discriminate between LCDM and MOND using local satellite galaxies, once accurate observations will be available. Intrigued? Have a look at it on arxiv!

Figure 1 (from Garaldi et al. 2018): Distribution of observed and simulated galaxies in the log(g_bar)-log(g_tot) plane. Triangles and squares indicate the median g_tot in bins of g_bar for the simulated Main Central Galaxies (MCGs) and Dwarf Central Galaxies (DCGs), respectively (errorbars enclose the central 68% of the data). The solid and dot-dashed curves are the best-fit RARs inferred from the MCGs and the observations. The large crosses represent the measurements for local dSph satellites presented in Lelli et al. 2017. The colored map displays the number density of the simulated MSGs. Each object corresponds to a bivariate Gaussian distribution reflecting the statistical errors. The framed ellipses show the typical 68% bootstrap region for objects with g_bar<10−13m s−2(left) and g_bar>10−10.5m s−2(right). The inset shows the density of the residuals between the MSGs and the best-fit RAR for the MCGs. The solid band is centred on the mean residual at fixed g_bar and has width equal to the mean measurement error for g_tot.

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