学术文献库

We show that $ς$, the radial location of the minimum in the differential radial mass profile $M^\prime(r)$ of a galaxy cluster, can probe the theory of gravity. We derived $M^\prime(r)$ of the dark matter halos of galaxy clusters from N-body cosmological simulations that implement two different theories of gravity: standard gravity in the $Λ$CDM model, and $f(R)$. We extracted 49169 dark matter halos in 11 redshift bins in the range $0\leq z\leq 1$ and in three different mass bins in the range $0.9<M_{200c}/10^{14}h^{-1}$M$_\odot<11$. We investigated the correlation of $ς$ with the redshift and the mass accretion rate (MAR) of the halos. We show that $ς$ decreases from $\sim 3R_{200c}$ to $\sim 2R_{200c}$ when $z$ increases from 0 to $1$ in the $Λ$CDM model. At $z\sim 0.1$, $ς$ decreases from $2.8R_{200c}$ to $\sim 2.5R_{200c}$ when the MAR increases from $\sim 10^4h^{-1}$M$_\odot$~yr$^{-1}$ to $\sim 2\times 10^5h^{-1}$M$_\odot$~yr$^{-1}$. In the $f(R)$ model, $ς$ is $\sim 15$% larger than in $Λ$CDM. The median test shows that for samples of $\gtrsim 400$ dark matter halos at $z\leq 0.8$, $ς$ is able to distinguish between the two theories of gravity with a $p$-value $\lesssim 10^{-5}$. Upcoming advanced spectroscopic and photometric programs will allow a robust estimation of the mass profile of enormous samples of clusters up to large clustercentric distances. These samples will allow us to statistically exploit $ς$ as probe of the theory of gravity, which complements other large-scale probes.