text: 277,77,1215258112384475136,19149703,Karina Voggel ✨🔭🏃🏼‍♀️,"Today our new paper on how we can find globular clusters with the help of @ESAGaia is out on the arxiv! with @anilcseth @caprastro & @sand_dave <LINK> @ESAGaia @anilcseth @caprastro @sand_dave We tried to find globular clusters in Centaurus A by using colour and astrometric excess factors in Gaia DR2. We realized that star clusters in nearby galaxies do not appear like standard point sources in Gaia. <LINK> @ESAGaia @anilcseth @caprastro @sand_dave Normally these excess factors are used as a quality assessment tool in Gaia to purge out bad sources! @ESAGaia @anilcseth @caprastro @sand_dave We have followe up a few candidates, and identified 5 brand new GCs in the outskirts of CenA. They actually are clearly visible as star clusters in good seeing imaging but we had not found them because the outer Halo of Gaia spans several square degrees on the sky. <LINK> @ESAGaia @anilcseth @caprastro @sand_dave These newly confirmed clusters (Blue datapoints) are now the record holders for the three most distant known GCs in CenA! This shows the power of this Gaia method to identify good candidates in the distant outskirts. <LINK> @ESAGaia @anilcseth @caprastro @sand_dave And we expect that this @ESAGaia method is applicable to find bright GCs in most Local Volume galaxies out to 25Mpc. Especially in those sparse outer Halos of galaxies! <LINK> @ESAGaia @anilcseth @caprastro @sand_dave On top of that we also show that the excess factors are directly correlated to the physical size of the GCs. Meaning that you can use the excess factors to get a rough size estimate of their sizes without the need for high-resolution HST imaging. <LINK>",https://arxiv.org/abs/2001.02243,"Tidally stripped galaxy nuclei and luminous globular clusters (GCs) are important tracers of the halos and assembly histories of nearby galaxies, but are difficult to reliably identify with typical ground-based imaging data. In this paper we present a new method to find these massive star clusters using Gaia DR2, focusing on the massive elliptical galaxy Centaurus A (Cen A). We show that stripped nuclei and globular clusters are partially resolved by Gaia at the distance of Cen A, showing characteristic astrometric and photometric signatures. We use this selection method to produce a list of 632 new candidate luminous clusters in the halo of Cen A out to a projected radius of 150 kpc. Adding in broadband photometry and visual examination improves the accuracy of our classification. In a spectroscopic pilot program we have confirmed 5 new luminous clusters, which includes the 7th and 10th most luminous GC in Cen\,A. Three of the newly discovered GCs are further away from Cen A in than all previously known GCs. Several of these are compelling candidates for stripped nuclei. We show that our novel Gaia selection method retains at least partial utility out to distances of 25 Mpc and hence is a powerful tool for finding and studying star clusters in the sparse outskirts of galaxies in the local universe. ","A Gaia-based catalog of candidate stripped nuclei and luminous globular