6 papers
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…
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…
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…
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…
A Spectroscopic Search for Dormant Black Holes in Low-Metallicity Binaries
Pranav Nagarajan, Kareem El-Badry, Henrique Reggiani +9
The discovery of the massive black hole (BH) system Gaia BH3 in pre-release Gaia DR4 data suggests that wide BH binaries with luminous companions may be significantly overrepresent…
A Fast, Analytic Empirical Model of the Gaia Data Release 3 Astrometric Orbit Catalog Selection Function
Casey Y. Lam, Kareem El-Badry, Joshua D. Simon
In June 2022, the Gaia mission released a catalog of astrometric orbital solutions for 168,065 binary systems, by far the largest such catalog to date. The catalog's selection func…