{
  "id": "2309.10404",
  "version": "v1",
  "published": "2023-09-19T08:10:09.000Z",
  "updated": "2023-09-19T08:10:09.000Z",
  "title": "Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions",
  "authors": [
    "Kyu-Hyun Chae"
  ],
  "comment": "14 pages, 12 figures, submitted to ApJ (this new work complements the paper ApJ, 952, 128 [arXiv:2305.04613] in an important way)",
  "categories": [
    "astro-ph.GA",
    "gr-qc",
    "hep-th"
  ],
  "abstract": "It is found that Gaia DR3 binary stars selected with stringent requirements on astrometric measurements and radial velocities naturally satisfy Newtonian dynamics without hidden close companions when projected separation $s > 2$ kau, showing that pure binaries can be selected. It is then found that pure binaries selected with the same criteria show a systematic deviation from the Newtonian expectation when $s < 2$ kau. When both proper motions and parallaxes are required to have precision better than 0.003 and radial velocities better than 0.2, I obtain 1558 statistically pure binaries within a 'clean' $G$-band absolute magnitude range. From this sample, I obtain an observed to Newtonian predicted kinematic acceleration ratio of $\\gamma_g=g_{\\rm{obs}}/g_{\\rm{pred}}=1.43^{+0.23}_{-0.19}$ for acceleration $< 10^{-10}$ m s$^{-2}$, in excellent agreement with a recent finding $1.43\\pm 0.06$ for a much larger general sample with the amount of hidden close companions self-calibrated. I also investigate the radial profile of stacked sky-projected relative velocities without a deprojection to the 3D space. The observed profile matches the Newtonian predicted profile for $s < 2$ kau without any free parameters but shows a clear deviation at a larger separation with a significance of $4.6\\sigma$. The projected velocity boost factor for $s>8$ kau is measured to be $\\gamma_{v_p} = 1.18\\pm 0.06$ matching $\\sqrt{\\gamma_g}$. Finally, for a small sample of 23 binaries with exceptionally precise radial velocities (precision $<0.0043$) the directly measured relative velocities in the 3D space also show a boost at larger separations. These results robustly confirm the recently reported gravitational anomaly at low acceleration for a general sample.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-09-19T08:10:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "statistically pure binaries free",
      "low acceleration",
      "robust evidence",
      "standard gravity",
      "hidden companions"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 14,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}