Michael Coughlin
Division of Physics Mathematics and Astronomy, California Institute of Technology (Pasadena, California, Etats-Unis d'Amérique)
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
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| « Search for and characterization of optical counterparts of gravitational waves » |
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Michael Coughlin |
| The detection of the binary neutron star GW170817 together with the observation of electromagnetic counterparts across the entire spectrum inaugurated a new era of multi-messenger astronomy. The hope for regular detections of counterparts highlights the need for improved strategies for follow-up and analysis of events of this kind. My talk will highlight a few endeavors towards this end. First of all, with the Zwicky Transient Facility recently achieving first light, it is now fruitful to use its unprecedented combination of depth, field of view, and survey cadence to perform Target of Opportunity observations. Using the ~50 square degree field of view of the instrument, it is possible to follow-up events from systems like the Fermi Gamma-Ray Burst Monitor, where it can be necessary to cover thousands of square degrees. We will demonstrate on short gamma-ray bursts how it is possible to use this system to do follow-up on this scale. Searching over sky areas of this size requires efficient follow-up of the many identified candidates is required. Towards this end, we use models derived from GW170817 to differentiate between kilonovae, gamma-ray burst afterglows, and supernova transients, and explore optimal cadences, passbands, and the required number of days of photometry available to differentiate them. Finally, we describe how we can incorporate wavelength-dependent opacities and emissivities calculated from atomic-structure data enabling us to model both the measured lightcurves and spectra of the kilonova detected in coincidence with GW170817. We show how to use these models to place constraints on the mass ratio and tidal deformability of the neutron stars. |
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vendredi 31 août 2018 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |