2025A&A...701A.119R -
Astronomy and Astrophysics, volume 701A119 (2025/9-1)
Forecast for a growth-rate measurement using peculiar velocities from LSST supernovae.
ROSSELLI D., CARRERES B., RAVOUX C., BAUTISTA J.E., FOUCHEZ D., KIM A.G., RACINE B., FEINSTEIN F., SANCHEZ B.O., VALADE A. (The LSST Dark Energy Science Collaboration)
Abstract (from CDS):
We investigate whether the cosmic growth-rate parameter fσ8 can be measured using peculiar velocities (PVs) derived from type Ia supernovae (SNe Ia) in the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST). We produced simulations of different SN types using a realistic LSST observing strategy that incorporated noise, a photometric detection from the difference-image analysis (DIA) pipeline, and a PV field modeled from the Uchuu universe machine simulations. We tested three different observational scenarios that ranged from ideal conditions with spectroscopic host galaxy redshifts and spectroscopic SN typing to realistic photometric typing that resulted in a contamination with non-Ia SNe. Using a maximum likelihood technique, we showed that the LSST can measure fσ8 with a precision of 10% in the redshift range 0.02 < z < 0.14 for our most realistic scenario. In three tomographic bins, the LSST will be able to constrain the growth-rate parameter with errors below 18% up to redshift z = 0.14. We also tested the contamination effect on the maximum likelihood method and found that for a contamination fraction below ∼2%, we recovered unbiased measurements. The results of this analysis highlight that the LSST SN sample is expected to complement traditional redshift-space distortion measurements at high redshift. This will provide a novel avenue for testing general relativity and different dark energy models.
Abstract Copyright:
© The Authors 2025
Journal keyword(s):
cosmological parameters - distance scale - large-scale structure of Universe
Simbad objects:
1
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2025A&A...701A.119R and select 'bookmark this link' or equivalent in the popup menu