Search Publications
Precise and Accurate Mass and Radius Measurements of Fifteen Galactic Red Giants in Detached Eclipsing Binaries
Lu, Jessica R.; Fulton, Benjamin J.; Kochanek, Christopher S. +9 more
Precise and accurate mass and radius measurements of evolved stars are crucial to calibrating stellar models. Stars in detached eclipsing binaries (EBs) are excellent potential calibrators because their stellar parameters can be measured with fractional uncertainties of a few percent, independent of stellar models. The All-Sky Automated Survey for…
A halo model approach for mock catalogs of time-variable strong gravitational lenses
Marshall, Philip J.; Oguri, Masamune; Birrer, Simon +5 more
Time delays in both galaxy- and cluster-scale strong gravitational lenses have recently attracted a lot of attention in the context of the Hubble tension. Future wide-field cadenced surveys, such as the LSST, are anticipated to discover strong lenses across various scales. We generate mock catalogs of strongly lensed QSOs and SNe on galaxy-, group…
Dark Energy Survey Year 6 Results: Point-Spread Function Modeling
Bechtol, K.; Smith, M.; Davis, T. M. +57 more
We present the point-spread function (PSF) modeling for weak lensing shear measurement using the full six years of the Dark Energy Survey (DES Y6) data. We review the PSF estimation procedure using the PIFF (PSFs In the Full FOV) software package and describe the key improvements made to PIFF and modeling diagnostics since the DES year three (Y3) …
Untangling Magellanic Streams
Conroy, Charlie; Cargile, Phillip A.; Naidu, Rohan P. +3 more
The Magellanic Stream (MS) is known to contain multiple H<small>I</small> strands and corresponding stellar populations are being discovered. Combining a sample of 17 stars from the H3 ("Hectochelle in the Halo at High Resolution") survey with 891 stars drawn from the Gaia DR3 catalog, we trace stars along a sub-dominant strand of the …
A 1.9 solar-mass neutron star candidate in a 2-year orbit
Bieryla, Allyson; Latham, David W.; Rix, Hans-Walter +10 more
We report discovery and characterization of a main-sequence G star orbiting a dark object with mass 1.90±0.04M⊙. The system was discovered via Gaia astrometry and has an orbital period of 731 days. We obtained multi-epoch RV follow-up over a period of 639 days, allowing us to refine the Gaia orbital solution and precisely constrain the masses of b…
A population of neutron star candidates in wide orbits from Gaia astrometry
Bieryla, Allyson; Latham, David W.; Rix, Hans-Walter +10 more
We report discovery and spectroscopic follow-up of 21 astrometric binaries containing solar-type stars and dark companions with masses near 1.4 M⊙. The simplest interpretation is that the companions are dormant neutron stars (NSs), though ultramassive white dwarfs (WDs) and tight WD+WD binaries cannot be fully excluded. We selected targets from Ga…
On the formation of a 33 solar-mass black hole in a low-metallicity binary
El-Badry, Kareem
A 33M⊙ black hole (BH) was recently discovered in an 11.6-year binary only 590 pc from the Sun. The system, Gaia BH3, contains a 0.8M⊙ low-metallicity giant () that is a member of the ED-2 stellar stream. This paper investigates whether the system could have formed via isolated binary evolution. I construct evolutionary models for metal-poor massi…
Galaxy assembly revealed by globular clusters
Chen, Yingtian; Gnedin, Oleg Y.
Many observable properties of globular clusters (GCs) provide valuable insights for unveiling the hierarchical assembly of their host galaxy. For the Milky Way (MW) in particular, GCs from different accreted satellite galaxies show distinct chemical, spatial, kinematic, and age distributions. Here we examine such clustering features for model GC p…
Comparing jet-shaped point symmetry in cluster cooling flows and supernovae
Soker, Noam
I point out similarities between point-symmetric X-ray morphologies in cooling flow groups and clusters of galaxies, which are observed to be shaped by jets, and point-symmetric morphologies of eight core-collapse supernova (CCSN) remnants. I identify these similarities by qualitative eye inspection of multiwavelength images. I use these similarit…
Spectroscopic Confirmation of an Ultra-Massive Galaxy in a Protocluster at z ∼ 4.9
Cooper, M. C.; Urbano Stawinski, Stephanie M.; Muzzin, Adam +8 more
We present spectroscopic confirmation of an ultra-massive galaxy (UMG) with log(M⋆/M⊙)=10.98±0.07 at zspec=4.8947 in the Extended Groth Strip (EGS), based on deep observations of Ly α emission with Keck/DEIMOS. The ultra-massive galaxy (UMG-28740) is the most massive member in one of the most significant overdensities in the EGS, with four additio…