Speaker
Description
The connection between gravitational wave (GW) sources, short gamma-ray bursts and their X-ray afterglows in GW170817 is a cornerstone for multi-messenger cosmology, allowing for an independent measurement of the cosmic expansion.
Gravitational wave signals alone cannot constrain the Hubble constant, H0, due to intrinsic degeneracies between redshift and the masses of the merging objects, and between luminosity distance and system’s inclination angle relative to the observer. Electromagnetic counterparts of GW signals break these degeneracies by providing direct redshift measurements and constraints on the binary’s inclination.
In this presentation, I will discuss how NewAthena will play a central role in the next decade of multi-messenger astrophysics.
The high-resolution offered by X-IFU will provide access to X-ray lines at the distances targeted by the third-generation gravitational waves detectors. These highly resolved spectra will deliver the missing redshift information. Meanwhile, WFI’s high sensitivity is well suited to observe faint GW afterglows over long timescales, thus constraining the inclination angle of binary systems.
In synergy with next-generation interferometers such as the Einstein Telescope and Cosmic Explorer, NewAthena will deliver cosmological measurements that are competitive with traditional probes, further highlighting the central role of neutron stars in multi-messenger cosmology and astronomy.
| Other topic / keywords: | Multi-Messenger Cosmology |
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