The Physics department colloquia are usually on Friday afternoons at 3:30 pm in Lapham Hall Room 160. Coffee and cookies are served at 3:15 pm in the same room. Anyone is welcome.

Monsters in the Dark: High Energy Signatures of Black Hole Formation with Multimessenger Astronomy
Alex Urban Research Assistant, UWM Physics Department

When two ultra-compact objects inspiral and violently merge it is a rare cosmic event, producing fantastically “luminous” gravitational wave emission. It is also fleeting, staying in the Laser Interferometer Gravitational-wave Observatory’s (LIGO) sensitive band only for somewhere between tenths of a second and several tens of minutes. However, when there is at least one neutron star, disk formation during the merger may power a slew of potentially detectable electromagnetic counterparts, such as short gamma-ray bursts (GRBs), afterglows, and kilonovae. These explosions span the full electromagnetic spectrum and are expected within seconds, hours or days of the merger event. To learn as much astrophysics as possible requires targeted observations at every stage of this process, demanding a coordinated worldwide effort across many facilities and multiple astronomical disciplines, all in nearly real-time.

In this dissertation, I outline some of the major obstacles facing the multimessenger astronomy effort, including computation, data analysis and sky localization for LIGO source candidates, as well as disseminating this information quickly to the astronomical community. I also report on the performance of some of these services during Advanced LIGO’s first Observing Run, and on my experience at LIGO Livingston Observatory during the first Observing Run of LIGO’s Advanced stage, during which the instruments directly detected gravitational waves for the very first time. (The transient source GW150914 was observed 14 September 2015, and is consistent with a binary black hole merger at redshift 0.09.) I also participate in time-domain optical astronomy with the intermediate Palomar Transient Factory (iPTF) collaboration, searching for orphaned afterglow candidates to better understand the nature of relativistic outbursts such as GRBs.