Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions
It is found that Gaia Data Release 3 binary stars selected with stringent requirements on astrometric measurements and radial velocities naturally satisfy Newtonian dynamics without hidden close companions when the projected separation s ≲ 2 kau, showing that pure binaries can be selected. It is the...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad0ed5 |
| _version_ | 1797361828227973120 |
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| author | Kyu-Hyun Chae |
| author_facet | Kyu-Hyun Chae |
| author_sort | Kyu-Hyun Chae |
| collection | DOAJ |
| description | It is found that Gaia Data Release 3 binary stars selected with stringent requirements on astrometric measurements and radial velocities naturally satisfy Newtonian dynamics without hidden close companions when the 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 0.005 and radial velocities better than 0.2, I obtain 2463 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 ${\gamma }_{g}={g}_{\mathrm{obs}}/{g}_{\mathrm{pred}}={1.49}_{-0.19}^{+0.21}$ for acceleration ≲10 ^−10 m s ^−2 , in excellent agreement with 1.49 ± 0.07 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 ≈5.0 σ . The projected velocity boost factor for s ≳ 5 kau is measured to be ${\gamma }_{{v}_{p}}=1.20\pm 0.06$ (stat) ±0.05 (sys) matching $\sqrt{{\gamma }_{g}}$ . Finally, for a small sample of 40 binaries with exceptionally precise radial velocities (fractional errors <0.005), 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. |
| first_indexed | 2024-03-08T15:59:00Z |
| format | Article |
| id | doaj.art-e47356d70bf44a0c82167f00555177db |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T15:59:00Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-e47356d70bf44a0c82167f00555177db2024-01-08T13:59:23ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01960211410.3847/1538-4357/ad0ed5Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden CompanionsKyu-Hyun Chae0https://orcid.org/0000-0002-6016-2736Department of Physics and Astronomy, Sejong University , 209 Neungdong-ro Gwangjin-gu, Seoul 05006, Republic of Korea ; chae@sejong.ac.kr, kyuhyunchae@gmail.comIt is found that Gaia Data Release 3 binary stars selected with stringent requirements on astrometric measurements and radial velocities naturally satisfy Newtonian dynamics without hidden close companions when the 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 0.005 and radial velocities better than 0.2, I obtain 2463 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 ${\gamma }_{g}={g}_{\mathrm{obs}}/{g}_{\mathrm{pred}}={1.49}_{-0.19}^{+0.21}$ for acceleration ≲10 ^−10 m s ^−2 , in excellent agreement with 1.49 ± 0.07 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 ≈5.0 σ . The projected velocity boost factor for s ≳ 5 kau is measured to be ${\gamma }_{{v}_{p}}=1.20\pm 0.06$ (stat) ±0.05 (sys) matching $\sqrt{{\gamma }_{g}}$ . Finally, for a small sample of 40 binaries with exceptionally precise radial velocities (fractional errors <0.005), 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.https://doi.org/10.3847/1538-4357/ad0ed5Binary starsModified Newtonian dynamicsNon-standard theories of gravityGravitation |
| spellingShingle | Kyu-Hyun Chae Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions The Astrophysical Journal Binary stars Modified Newtonian dynamics Non-standard theories of gravity Gravitation |
| title | Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions |
| title_full | Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions |
| title_fullStr | Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions |
| title_full_unstemmed | Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions |
| title_short | Robust Evidence for the Breakdown of Standard Gravity at Low Acceleration from Statistically Pure Binaries Free of Hidden Companions |
| title_sort | robust evidence for the breakdown of standard gravity at low acceleration from statistically pure binaries free of hidden companions |
| topic | Binary stars Modified Newtonian dynamics Non-standard theories of gravity Gravitation |
| url | https://doi.org/10.3847/1538-4357/ad0ed5 |
| work_keys_str_mv | AT kyuhyunchae robustevidenceforthebreakdownofstandardgravityatlowaccelerationfromstatisticallypurebinariesfreeofhiddencompanions |