2024/02/08 by Chae, Kyu-Hyun · 3 citations
#Astrophysics of Galaxies (astro-ph.GA) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2402.05720
Low-acceleration gravitational anomaly is investigated with a new method of exploiting the normalized velocity profile v≡ vp/vc of wide binary stars as a function of the normalized sky-projected radius s/r_\rmM where vp is the sky-projected relative velocity between the pair, vc is the Newtonian circular velocity at the sky-projected separation s, and r_\rmM is the MOND radius. With a Monte Carlo method Gaia observed binaries and their virtual Newtonian counterparts are probabilistically distributed on the s/r_\rmM versus v plane and a logarithmic velocity ratio parameter Γ is measured in the bins of s/r_\rmM. With three samples of binaries covering a broad range in size, data quality, and implied fraction of hierarchical systems including a new sample of 6389 binaries selected with accurate distances and radial velocities, I find a unanimous systematic variation from the Newtonian flat line. With Γ=0 at s/r_\rmM\lesssim 0.15 or s\lesssim 1~kilo astronomical units (kau), I get Γ=0.068± 0.015 (stat) -0.015+0.024 (syst) for s/r_\rmM \gtrsim 0.7 or s\gtrsim 5~kau. The gravitational anomaly (i.e. acceleration boost) factor given by γg = 102Γ is measured to be γg = 1.37-0.09+0.10 (stat) -0.09+0.16 (syst). With a reduced χ2 test of Newtonian and Milgromian nonrelativistic theories, I find that Newtonian gravity is ruled out at 5.8σ (χ2ν=9.4) by the new sample (and 9.2σ by the largest sample used). The Milgromian AQUAL theory is acceptable with 0.5\lesssim χ2ν\lesssim 3.1. These results agree well with earlier results with the "acceleration-plane analysis" for a variety of samples and the "stacked velocity profile analysis" for a pure binary sample.