학술논문

Where and When: Optimal Scheduling of the Electromagnetic Follow-up of Gravitational-wave Events Based on Counterpart Light-curve Models.
Document Type
Article
Source
Astrophysical Journal. 9/1/2017, Vol. 846 Issue 1, p1-1. 1p.
Subject
*GRAVITATIONAL waves
*LIGHT curves of variable stars
*ELECTROMAGNETIC waves
*NEUTRON stars
*GAMMA ray bursts
*STELLAR mergers
Language
ISSN
0004-637X
Abstract
The electromagnetic (EM) follow-up of a gravitational-wave (GW) event requires scanning a wide sky region, defined by the so-called “skymap,” to detect and identify a transient counterpart. We propose a novel method that exploits the information encoded in the GW signal to construct a “detectability map,” which represents the time-dependent (“when”) probability of detecting the transient at each position of the skymap (“where”). Focusing on the case of a neutron star binary inspiral, we model the associated short gamma-ray burst afterglow and macronova emission using the probability distributions of binary parameters (sky position, distance, orbit inclination, mass ratio) extracted from the GW signal as inputs. The resulting family of possible light curves is the basis for constructing the detectability map. As a practical example, we apply the method to a simulated GW signal produced by a neutron star merger at 75 Mpc whose localization uncertainty is very large (∼1500 deg2). We construct observing strategies for optical, infrared, and radio facilities based on the detectability maps, taking VST, VISTA, and MeerKAT as prototypes. Assuming limiting fluxes of , (AB magnitudes), and () for ∼1000 s of exposure each, the afterglow and macronova emissions are successfully detected with a minimum observing time of 7, 15, and 5 hr respectively. [ABSTRACT FROM AUTHOR]