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The first generation of large-scale chemical tagging surveys, in particular the HERMES/GALAH million star survey, promises to vastly expand our understanding of the chemical and dynamical evolution of the Galaxy. This, however, is contingent on our ability to confidently perform chemical tagging on such a large data-set. Chemical homogeneity has been observed across a range of elements within several Galactic open clusters, yet the level to which this is the case globally, and particularly in comparison to the scatter across clusters themselves, is not well understood. The patterns of elements in coeval cluster members, occupying a complex chemical abundance space, are rooted in the evolution, ultimately the nature of the very late stages, of early generations of stars. The current astrophysical models of such stages are not yet sufficient to explain all observations, combining with our significant gaps in the understanding of star formation, makes this a difficult arena to tackle theoretically. Here, we describe a robust pair-wise metric used to gauge the chemical difference between two stellar components. This metric is then applied to a database of high-resolution literature abundance sources to derive a function describing the probability that two stars are of common evolutionary origin. With this cluster probability function, it will be possible to report a confidence, grounded in empirical observational evidence, with which clusters are detected, independent of the group finding methods. This formulation is also used to probe the role of chemical dimensionality, and that of individual chemical species, on the ability of chemical tagging to differentiate coeval groups of stars.
We present a new scheme, $it{galtag}$, for refining the photometric redshift measurements of faint galaxies by probabilistically tagging them to observed galaxy groups constructed from a brighter, magnitude-limited spectroscopy survey. First, this me
Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general, are important unsolved problems in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field ar
We present a study using the second data release of the GALAH survey of stellar parameters and elemental abundances of 15 pairs of stars identified by Oh et al 2017. They identified these pairs as potentially co-moving pairs using proper motions and
Chemical tagging has great promise as a technique to unveil our Galaxys history. Grouping stars based on their similar chemistry can establish details of the star formation and merger history of the Milky Way. With precise measurements of stellar che
We predict the stellar mass -- halo mass (SMHM) relationship for dwarf galaxies, using simulated galaxies with peak halo masses of M$_{rm peak} = 10^{11}$ M$_{odot}$ down into the ultra-faint dwarf range to M$_{rm peak} =$ 10$^7$ M$_{odot}$. Our simu