Kilonovae: nUV/Optical/IR Counterparts of Neutron Star Binary Mergers with TSO

TL;DR

This paper discusses the importance of rapid, broad-band electromagnetic follow-up observations of neutron star mergers, emphasizing the role of the proposed TSO telescope in advancing understanding of kilonovae and nucleosynthesis.

Contribution

It introduces the TSO telescope concept as a key instrument for prompt, high-sensitivity, broad-band follow-up of neutron star merger events in the upcoming decade.

Findings

TSO will provide rapid imaging and spectroscopy in 4 bands from 0.3 to 5 microns.

TSO spectra will help constrain neutron star structure and nucleosynthesis processes.

The paper highlights the need for coordinated multi-wavelength follow-up for gravitational wave events.

Abstract

With the epochal first detection of gravitational waves from a binary neutron star (NS) merger with the GW170817 event, and its direct confirmation that NS-NS mergers are significant sources of the of the r-process nucleosynthesis of heavy elements, an immense new arena for prompt EM (X-rays through IR and radio) studies of fundamental physics has been opened. Over the next decade, GW observatories will expand in scale and sensitivity so the need for facilities that can provide prompt, high sensitivity, broad-band EM followup becomes more urgent. NS-NS or NS-black hole (BH) mergers will be instantly recognized (and announced) by the LIGO-international collaboration. LSST will be a prime resource for rapid tiling of what will usually be large (~10-100 degree squared) error boxes. X-ray through IR Telescopes in space with (nearly) full-sky access that can rapidly image and tile are crucial for providing the earliest imaging and spectroscopic studies of the kilonova emission immediately following NS-NS mergers. The Time-domain Spectroscopic Observatory (TSO) is a proposed Probe-class 1.3 m telescope at L2, with imaging and spectroscopy (R = 200, 1800) in 4 bands (0.3 - 5 micron) and rapid slew capability to 90% of sky. TSO nUV-mid-IR spectra will enable new constraints on NS structure and nucleosynthesis.