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arXiv · 2305.19668

Quasars: standard candles up to z=7.5 with the precision of Supernovae Ia

Maria Giovanna Dainotti·Giada Bargiacchi·Aleksander Łukasz Lenart·Shigehiro Nagataki·Salvatore Capozziello
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Abstract

Currently, the $Λ$ Cold Dark Matter model, which relies on the existence of cold dark matter and a cosmological constant $Λ$, best describes the Universe. However, we lack information in the high-redshift ($z$) region between Type Ia Supernovae (SNe Ia) (up to $z=2.26$) and the Cosmic Microwave Background ($z=1100$), an interval crucial to test cosmological models and their possible evolution. We have defined a sample of 983 Quasars up to $z=7.54$ with reduced intrinsic dispersion $δ=0.007$ which determines the matter density parameter $Ω_M$ with the same precision of SNe Ia. Although previous analysis have been used Quasars as cosmological tools (e.g. Risaliti and Lusso 2019), this is the first time that high-redshift sources, in this case Quasars, as standalone cosmological probes yield such tight constraints on $Ω_M$. Our results show the importance of correcting cosmological relationships for selection biases and redshift evolution and how the choice of a golden sample reduces considerably the intrinsic scatter. This proves the reliability of Quasars as standard cosmological candles.

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Maria Giovanna Dainotti, Giada Bargiacchi, Aleksander Łukasz Lenart, Shigehiro Nagataki, Salvatore Capozziello. 2023-05-31. Quasars: standard candles up to z=7.5 with the precision of Supernovae Ia. https://doi.org/10.3847/1538-4357%2Faccea0

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