Accurate measurement of the Hubble constant from standard sirens such as the gravitational wave (GW) sources with electromagnetic counterparts relies on the robust peculiar velocity correction of the redshift of the host galaxy. We show in this work that the peculiar velocity of the host galaxies exhibits a correlation with the properties of the host galaxy primarily such as its stellar mass and this correlation also evolves with redshift. As the galaxies of higher stellar mass tend to form in galaxies with higher halo masses which are located in spatial regions having a non-linear fluctuation in the density field of the matter distribution, the root mean square peculiar velocity of more massive galaxies is higher. As a result, depending on the formation channel of the binary compact objects, the peculiar velocity contamination to the galaxies will be different. The variation in the peculiar velocity of the host galaxies can lead to a significant variation in the estimation of the Hubble constant inferred using sources such as binary neutron stars. For the network of GW detectors such as LIGO-Virgo-KAGRA (LVK), LVK+LIGO-India, and Cosmic Explorer + Einstein Telescope, the variation in the precision of Hubble constant inferred from 10 bright siren events can vary from $\sim 5.4 - 6~{{\ \rm per \, cent}}$, $\sim 4.5 - 5.3~{{\ \rm per \, cent}}$, and $\sim 1.1 - 2.7~{{\ \rm per \, cent}}$, respectively. The impact of such a correlation between peculiar velocity and stellar mass on the inference of the Hubble constant is not only limited to GW sources but also applicable to type-Ia supernovae.
The measurement of the expansion history of the Universe from the redshift unknown gravitational wave (GW) sources (dark GW sources) detectable from the network of LIGO-Virgo-KAGRA (LVK) detectors depends on the synergy with the galaxy surveys having accurate redshift measurements over a broad redshift range, large sky coverage, and detectability of fainter galaxies.In this work, we explore the possible synergy of the LVK with the spectroscopic galaxy surveys, such as DESI and SPHEREx, to measure the cosmological parameters which are related to the cosmic expansion history and the GW bias parameters. We show that by using the 3D spatial cross-correlation between the dark GW sources and the spectroscopic galaxy samples, we can measure the value of Hubble constant with about $2{{\ \rm per\ cent}}$ and $1.5{{\ \rm per\ cent}}$ precision from LVK+DESI and LVK+SPHEREx, respectively within the 5 yr of observation time with $50{{\ \rm per\ cent}}$ duty-cycle. Similarly, the dark energy equation of state can be measured with about $10{{\ \rm per\ cent}}$ and $8{{\ \rm per\ cent}}$ precision from LVK+DESI and LVK+SPHEREx, respectively. We find that due to the large sky coverage of SPHEREx than DESI, performance in constraining the cosmological parameters is better from the former than the latter. By combining Euclid along with DESI and SPHEREx, a marginal gain in the measurability of the cosmological parameters is possible from the sources at high redshift (z ≥ 0.9).
more » « less- NSF-PAR ID:
- 10362896
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 511
- Issue:
- 2
- ISSN:
- 0035-8711
- Page Range / eLocation ID:
- p. 2782-2795
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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