text: 170,34,1364465902134165505,1968365508,Samaya Nissanke (she/her) 💙,"Group news: new paper by PhD student @GRaaymakers on “the challenges ahead for multi messenger analyses of gravitational waves and kilonova: a case study on GW190425.”V proud of Geert & paper after 2 + yrs of developing the framework & analyses. <LINK> 22 pages long, quite a lot of physics in it, & an end to end analysis developed by Geert and pause for reflection by the group & hopefully useful for the community! Well done @GRaaymakers for this comprehensive & challenging paper, and thank you to our excellent collaborators, @FrancoisFoucart @BullaMattia @astro_rafernan @ameliahenkel @tedwards2412 @AntierSarah & many others not on twitter who all contributed wonderfully! & thanks to @NWO_Science for supporting this work through a VIDI. Written originally in 2014, then reapplied in 2015, awarded in 2016 but the actual discovery of gravitational waves and multi messenger members, plus becoming new mum, had us occupied. Mission completed! And code will be made open source shortly!",https://arxiv.org/abs/2102.11569,"In recent years, there have been significant advances in multi-messenger astronomy due to the discovery of the first, and so far only confirmed, gravitational wave event with a simultaneous electromagnetic (EM) counterpart, as well as improvements in numerical simulations, gravitational wave (GW) detectors, and transient astronomy. This has led to the exciting possibility of performing joint analyses of the GW and EM data, providing additional constraints on fundamental properties of the binary progenitor and merger remnant. Here, we present a new Bayesian framework that allows inference of these properties, while taking into account the systematic modeling uncertainties that arise when mapping from GW binary progenitor properties to photometric light curves. We extend the relative binning method presented in Zackay et al. (2018) to include extrinsic GW parameters for fast analysis of the GW signal. The focus of our EM framework is on light curves arising from r-process nucleosynthesis in the ejected material during and after merger, the so called kilonova, and particularly on black hole - neutron star systems. As a case study, we examine the recent detection of GW190425, where the primary object is consistent with being either a black hole (BH) or a neutron star (NS). We show quantitatively how improved mapping between binary progenitor and outflow properties, and/or an increase in EM data quantity and quality are required in order to break degeneracies in the fundamental source parameters. ","The Challenges Ahead for Multimessenger Analyses of Gravitational Waves