English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

It is found that Gaia DR3 binary stars selected with stringent requirementson astrometric measurements and radial velocities naturally satisfy Newtoniandynamics without hidden close companions when projected separation $s \lesssim2$ kau, showing that pure binaries can be selected. It is then found that purebinaries selected with the same criteria show a systematic deviation from theNewtonian expectation when $s \gtrsim 2$ kau. When both proper motions andparallaxes are required to have precision better than 0.005 and radialvelocities better than 0.2, I obtain 2,463 statistically pure binaries within a`clean' $G$-band absolute magnitude range. From this sample, I obtain anobserved to Newtonian predicted kinematic acceleration ratio of$\gamma_g=g_{\rm{obs}}/g_{\rm{pred}}=1.49^{+0.21}_{-0.19}$ for acceleration$\lesssim 10^{-10}$ m s$^{-2}$, in excellent agreement with $1.49\pm 0.07$ fora much larger general sample with the amount of hidden close companionsself-calibrated. I also investigate the radial profile of stacked sky-projectedrelative velocities without a deprojection to the 3D space. The observedprofile matches the Newtonian predicted profile for $s \lesssim 2$ kau withoutany free parameters but shows a clear deviation at a larger separation with asignificance of $\approx 5.0\sigma$. The projected velocity boost factor for$s\gtrsim 5$ kau is measured to be $\gamma_{v_p} = 1.20\pm 0.06$ (stat) $\pm0.05$ (sys) matching $\sqrt{\gamma_g}$. Finally, for a small sample of 40binaries with exceptionally precise radial velocities (fractional error$<0.005$) the directly measured relative velocities in the 3D space also show aboost at larger separations. These results robustly confirm the recentlyreported gravitational anomaly at low acceleration for a general sample.

Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions