Multi-messenger astronomy with a Southern-Hemisphere gravitational-wave observatory

Abstract

Joint observations of gravitational waves and electromagnetic counterparts will answer questions about cosmology, gamma-ray bursts, and the behaviour of matter at supranuclear densities. The addition of a Southern-Hemisphere gravitational-wave observatory to proposed global networks creates a longer baseline, which is beneficial for sky localisation. We analyse how an observatory in Australia can enhance the multi-messenger astronomy capabilities of future networks. We estimate the number of binary neutron star mergers with joint observations of gravitational waves and kilonova counterparts detectable by the Vera C. Rubin Observatory. First, we consider a network of upgrades to current observatories. Adding an Australian observatory to a three-observatory network (comprising two observatories in the USA and one in Europe) boosts the rate of joint observations from $2.5_{-2.0}^{+4.5}$ per year to $5.6_{-4.5}^{+10}$ per year (a factor of two improvement). Then, we consider a network of next-generation observatories. Adding a $20$ km Australian observatory to a global network of a Cosmic Explorer $40$ km in the USA and an Einstein Telescope in Europe only marginally increases the rate from $40_{-32}^{+71}$ per year to $44_{-35}^{+79}$ per year (a factor of 1.1 improvement). The addition of an Australian observatory, however, ensures that at least two observatories are online far more often. When the Cosmic Explorer $40$ km is offline for a major upgrade, the Australian observatory increases the joint observation rate from $0.5_{-0.4}^{+0.8}$ per year to $38_{-30}^{+68}$ per year (a factor of 82 improvement). When the Einstein Telescope is offline, the joint observation rate increases from $0.2_{-0.1}^{+0.3}$ per year to $19_{-15}^{+34}$ per year (a factor of 113 improvement). We sketch out the broader science case for a Southern-Hemisphere gravitational-wave observatory.

v1, 13 pages, 7 figures. Submitted to PRD on August 24 2023

References in corpus (17)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Multi-messenger Observations of a Binary Neutron Star Merger
• Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A
• Advanced LIGO
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• A gravitational-wave standard siren measurement of the Hubble constant
• Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
• Use and Abuse of the Fisher Information Matrix in the Assessment of Gravitational-Wave Parameter-Estimation Prospects
• Kilonovae
• Accurate evolutions of inspiralling neutron-star binaries: prompt and delayed collapse to black hole
• Spectral properties of the post-merger gravitational-wave signal from binary neutron stars
• Follow up of GW170817 and its electromagnetic counterpart by Australian-led observing programs
• Exploring the sensitivity of gravitational wave detectors to neutron star physics
• $\text{GWFAST}$: a Fisher information matrix Python code for third-generation gravitational-wave detectors
• Gravitational-wave cosmology with dark sirens: state of the art and perspectives for 3G detectors

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• The Critical Role of LIGO-India in the Era of Next-Generation Observatories
• Impact of weak lensing on bright standard siren analyses
• Significant challenges for astrophysical inference with next-generation gravitational-wave observatories