Institute for Advanced Study Informal Astrophysics Seminar

The electromagnetic radiation observed following the neutron star (NS) merger event, that was recently detected by LIGO, provide constraints on the properties of the material ejected during the merger process. These constraints will be discussed in the first part of the talk: The observed UV to IR radiation are consistent with a single component low opacity fast ejecta, in intension with the results of NS merger simulations; The inferred mass fraction of heavy (A>140) r-process elements is ~30 times below the value required to account for the solar abundance. The second part of the talk will be devoted to the ULTRASAT space UV mission. ULTRASAT will revolutionize our ability to study transient astrophysical sources and, in particular,  will enable us to detect, localize and follow-up the electromagnetic emission of NS-NS and NS-black hole mergers over the entire sky (excluding the Sun's direction), on a time scale of minutes, out to a distance exceeding the horizon of gravitational wave detectors.