One acceleration measurement equals ~10^5 phase-space measurements for local dark matter density estimation, with acceleration outperforming Jeans modeling in both equilibrium and perturbed Milky Way simulations.
Gaia reveals a metal-rich in-situ component of the local stellar halo
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
We use the first Gaia data release, combined with RAVE and APOGEE spectroscopic surveys, to investigate the origin of halo stars within <~3 kpc from the Sun. We identify halo stars kinematically, as moving with a relative speed of at least 220 km/s with respect to the local standard of rest. These stars are in general more metal-poor than the disk, but surprisingly, half of our halo sample is comprised of stars with [Fe/H]>-1. The orbital directions of these metal-rich halo stars are preferentially aligned with the disk rotation, in sharp contrast with the isotropic orbital distribution of the more metal-poor halo stars. We find similar properties in the Latte cosmological zoom-in simulation of a Milky Way-like galaxy from the FIRE project. In Latte, metal-rich halo stars formed primarily inside of the solar circle, while lower-metallicity halo stars preferentially formed at larger distances (extending beyond the virial radius). This suggests that metal-rich halo stars in the Solar neighborhood in fact formed in-situ within the Galactic disk rather than having been accreted from satellite systems. These stars, currently on halo-like orbits, therefore have likely undergone substantial radial migration/heating.
years
2026 3representative citing papers
Giant-planet hosts preferentially formed in the metal-rich inner Galaxy and later migrated, while rocky-only systems are less centrally concentrated and show smaller radial excursions.
High-precision analysis of TYC 6044-714-1 favors s+r nucleosynthesis over i-process models, which require implausible conditions and mismatch Ba isotopes.
citing papers explorer
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An Acceleration is Worth a Hundred Thousand Phase Space Measurements
One acceleration measurement equals ~10^5 phase-space measurements for local dark matter density estimation, with acceleration outperforming Jeans modeling in both equilibrium and perturbed Milky Way simulations.
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Probing the origins. III. Exoplanet demographics across Galactic birth radii
Giant-planet hosts preferentially formed in the metal-rich inner Galaxy and later migrated, while rocky-only systems are less centrally concentrated and show smaller radial excursions.
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Observational Signatures and Constraints on the Intermediate Neutron-Capture Process. The Case of the CEMP star TYC 6044-714-1 (RAVE J094921.8-161722)
High-precision analysis of TYC 6044-714-1 favors s+r nucleosynthesis over i-process models, which require implausible conditions and mismatch Ba isotopes.