A Program for Multi-Messenger Standard Siren Cosmology in the Era of LIGO A+, Rubin Observatory, and Beyond

Abstract

The most promising variation of the standard siren technique combines gravitational-wave (GW) data for binary neutron star (BNS) mergers with redshift measurements enabled by their electromagnetic (EM) counterparts, to constrain cosmological parameters such as H 0 , Ω m , and w 0 . Here we evaluate the near-and long-term prospects of multi-messenger cosmology in the era of future GW observatories: Advanced LIGO Plus (A+, 2025), Voyager-like detectors (2030s), and Cosmic Explorer-like detectors (CE, 2035 and beyond). We show that the BNS horizon distance of ≈ 700 Mpc for A+ is well-matched to the sensitivity of the Vera C. Rubin Observatory (VRO) for kilonova detections. We find that one year of joint A+ and VRO observations will constrain the value of H 0 to percent-level precision, given a small investment of VRO time dedicated to targetof-opportunity GW follow-up. In the Voyager era, the BNS-kilonova observations begin to constrain Ω m with an investment of a few percent of VRO time. With the larger BNS horizon distance in the Cosmic Explorer era, on-axis short gamma-ray bursts (SGRBs) and their afterglows (though accompanying only some of the GW-detected mergers) supplant kilonovae as the most promising counterparts for redshift identification. We show that five years of joint observations with Cosmic Explorer-like facilities and a next-generation gammaray satellite with localization capabilities similar to that presently possible with Swift could constrain both Ω m and w 0 to 15 − 20%. We therefore advocate for a robust target-of-opportunity (ToO) program with VRO, and a wide-field gamma-ray satellite with improved sensitivity in the 2030s, to enable standard siren cosmology with next-generation gravitational wave facilities.

Tight multi-messenger constraints on the neutron star equation of state from GW170817 and a forward model for kilonova light curve synthesis

“…, in order to make follow-up observations more efficient. This is especially relevant given the possibility of target-of-opportunity GW follow-up with the upcoming Vera Rubin Observatory (Margutti et al 2018a;Cowperthwaite et al 2019;Smith et al 2019;Chen et al 2020).…”

Forecast for cosmological parameter estimation with gravitational-wave standard sirens from the LISA-Taiji network

“…Therefore, the current development of cosmology can be divided into two main aspects: (i) further extending the standard ΛCDM model [8][9][10]; and (ii) developing more low-redshift observation projects aimed at precisely measuring the late universe. For the second aspect, the gravitational-wave (GW) standard siren [11] is one of the most promising options and has been widely discussed [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

Cosmology in the dark: On the importance of source population models for gravitational-wave cosmology

“…They all concur on the rapid increase in difficulty for obtaining reliable and precise redshift measurements from electromagnetic observations as the GW sensitivity improves and the average distance of the detected events increases. The search for electromagnetic counterparts becomes more challenging [29,30]: sources at greater distances have dimmer counterparts and a larger number of potential host galaxies. Also the lack of completeness of galaxy surveys to high redshifts prevents the use of the statistical association for the large fraction of BBHs that will be observed by the future GW detectors [31].…”