390 citations · 929 across the 31 of their papers we have counts for
15 papers · 1 filter
A Quality Framework for Testing Gravity with Wide Binaries: No Evidence for MOND
Stephen A. Cookson, Indranil Banik, Kareem El-Badry +4
Wide binaries (WBs) offer a unique opportunity to test gravity in the low-acceleration regime, where modifications such as Milgromian dynamics (MOND) predict measurable deviations…
Discovery of Galactic center ejected star in DESI DR1
Manuel Cavieres, Sergey E. Koposov, Elena Maria Rossi +2
Hypervelocity stars (HVSs) are stars ejected from the Galactic Centre (GC) through tidal interactions with the central supermassive black hole. Formed in the immediate vicinity of…
Searching for stars ejected from the Galactic Centre in DESI
Sill Verberne, Sergey E. Koposov, Elena Maria Rossi +1
Dynamical interactions between stars and the super massive black hole Sgr A* at the Galactic Centre (GC) may eject stars into the Galactic halo. While recent fast ejections by Sgr…
Dynamics of recaptures, ejections and mergers of stellar mass binaries over multiple encounters with SgrA*
Biancamaria Sersante, Zephyr Penoyre, Elena Maria Rossi
A common origin for a host of stellar phenomena in galactic centres is the tidal encounter between stellar binaries and a massive black hole (MBH), known as the ``Hills mechanism''…
Disruptions of stars and binary systems on chaotic orbits in an axisymmetric Milky Way center
Zephyr Penoyre, Elena Maria Rossi, Nicholas C. Stone
Non-spherical potentials allow a wide range of trajectories, both regular and chaotic, whose periapse distances can vary orbit to orbit. In particular chaotic trajectories can brin…
Double progenitor origin of the S-star cluster
Sill Verberne, Elena Maria Rossi, Sergey E. Koposov +3
The origin of the cluster of S-stars located in the Galactic Centre is tied to the supermassive black hole Sagittarius A*, but exactly how is still debated. In this paper, we inves…
Improved constraints on Galactic Centre ejection of hypervelocity stars based on novel search method
Sill Verberne, Elena Maria Rossi, Sergey E. Koposov +6
Hypervelocity stars (HVSs) are stars which have been ejected from the Galactic Centre (GC) at velocities of up to a few thousand km/s. They are tracers of the Galactic potential an…
Carbon enrichment in APOGEE disk stars as evidence of mass transfer in binaries
Steve Foster, Ricardo P. Schiavon, Denise B. de Castro +10
Carbon abundances in first-ascent giant stars are usually lower than those of their main-sequence counterparts. At moderate metallicities, stellar evolution of single stars cannot…
Gaia DR3 detectability of unresolved binary systems
Alfred Castro-Ginard, Zephyr Penoyre, Andrew R. Casey +10
Gaia can not individually resolve very close binary systems, however, the collected data can still be used to identify them. A powerful indicator of stellar multiplicity is the sou…
Radial velocities from Gaia BP/RP spectra
Sill Verberne, Sergey E. Koposov, Elena M. Rossi +3
The Gaia mission has provided us full astrometric solutions for over 1.5B sources. However, only the brightest 34M of those have radial velocity measurements. As a proof of concept…
Stellar-mass black holes in the Hyades star cluster?
Stefano Torniamenti, Mark Gieles, Zephyr Penoyre +3
Astrophysical models of binary-black hole mergers in the Universe require a significant fraction of stellar-mass black holes (BHs) to receive negligible natal kicks to explain the…
Binary deviations from single object astrometry
Zephyr Penoyre, Vasily Belokurov, N. Wyn Evans +2
Most binaries are undetected. Astrometric reductions of a system using the assumption that the object moves like a single point mass can be biased by unresolved binary stars. The d…
A Drop in the Pond: The Effect of Rapid Mass Loss on the Dynamics and Interaction Rate of Collisionless Particles
Zephyr Penoyre, Zoltán Haiman
In symmetric gravitating systems experiencing rapid mass loss, particle orbits change almost instantaneously, which can lead to the development of a sharply contoured density profi…
The Origin and Evolution of Fast and Slow Rotators in the Illustris Simulation
Zephyr Penoyre, Benjamin P. Moster, Debora Sijacki +1
Using the Illustris simulation, we follow thousands of elliptical galaxies back in time to identify how the dichotomy between fast and slow rotating ellipticals (FRs and SRs) devel…
Bringing the Galaxy's dark halo to life
T. Piffl, Z. Penoyre, J. Binney
We present a new method to construct fully self-consistent equilibrium models of multi-component disc galaxies similar to the Milky Way. We define distribution functions for the st…