Using globular clusters to test gravity in the weak acceleration regime: NGC 6171

dc.creatorScarpa, Riccardo
dc.creatorMarconi, Gianni
dc.creatorGilmozzi, Roberto
dc.date2004-11-03
dc.date.accessioned2026-07-07T06:22:53Z
dc.date.available2026-07-07T06:22:53Z
dc.descriptionAs part of an ongoing program to test Newton's law of gravity in the low acceleration regime using globular clusters, we present here new results obtained for NGC 6171. Combining VLT spectra for 107 stars with data from the literature, we were able to trace the velocity dispersion profile up to 16 pc from the cluster center, probing accelerations of gravity down to 3.5e-9 cm/s/s. The velocity dispersion is found to remain constant at large radii rather than follow the Keplerian falloff. Similar results were previously found for the globular clusters $ω$ Centauri and M15. We have now studied three clusters and all three have been found to have a flat dispersion profile beyond the radius where their internal acceleration of gravity is ~ 1e-8 cm/s/s. Whether this indicates a failure of Newtonian dynamics or some more conventional dynamical effect (e.g., tidal heating) is still unclear. However, the similarities emerging between globular clusters and elliptical galaxies seem to favor the first of the two possibilities.
dc.descriptionAs presented in "Baryons in Dark Matter Halos", 5-9 October 2004, Novigrad, Croatia. Four pages, two figures
dc.identifierhttps://arxiv.org/abs/astro-ph/0411078
dc.identifierhttp://arxiv.org/abs/astro-ph/0411078
dc.identifierPoS BDMH2004 (2004) 055
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/96048
dc.subjectAstrophysics
dc.titleUsing globular clusters to test gravity in the weak acceleration regime: NGC 6171
dc.typetext

Files

Collections