collaborators

8 papers

astro-ph.SR2026

Spectroscopic follow-up of compact object binary candidates from Gaia DR3: White dwarfs, neutron stars, black holes, and the parallax zeropoint

Kareem El-Badry, David W. Latham, Hans-Walter Rix +12

Astrometry and radial velocities (RVs) from Gaia DR3 yielded orbits for hundreds of thousands of binary systems, including several samples proposed to contain black holes (BHs), ne…

astro-ph.SR2026

Lithium as a Signpost for Compact Object Binary Candidates in the LAMOST Medium Resolution Survey

Yang Shen, Joshua D. Simon, Kareem El-Badry +1

Binary systems with black hole or neutron star companions are often associated with lithium enhancement. Gaia NS1, a recently discovered neutron-star binary with a lithium-enhanced…

astro-ph.EP2026

TOI-7169 b: A Hot Jupiter Transiting a Metal-Poor Star

Joshua D. Simon, Joseph E. Rodriguez, Jhon Yana Galarza +38

Most known planets are found around metal-rich host stars, which has made it difficult to determine whether a lower metallicity limit for planet formation exists and how the proper…

astro-ph.SR2026

Radial Velocity Orbital Solutions for Candidate Black Hole and Neutron Star Binary Systems in the Gaia Data Release 3 Catalog

Joshua D. Simon, Casey Y. Lam, Kareem El-Badry +8

We present spectroscopic followup observations of binary systems from the Gaia Data Release 3 (DR3) binary catalog that were selected to have large enough mass functions for their…

astro-ph.EP2025

Hidden Companions of the Early Milky Way I. New alpha-Enhanced Exoplanet Hosts

Thiago Ferreira, Jhon Yana Galarza, Henrique Reggiani +15

Planet formation in the chemically ancient, dynamically heated Galactic thick disc remains poorly constrained, owing to the expectation that its low solid reservoirs, short disc li…

astro-ph.SR2025

A search for black holes with metal-poor stellar companions: I. Survey sample selection and single epoch radial velocity follow-up

Casey Y. Lam, Joshua D. Simon, Kareem El-Badry +3

Stellar-mass black holes (BHs) above are predicted to form from low-metallicity progenitors, but direct detections of such systems in the Milky Way remain scarce. Moti…