Search Publications
Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics beyond ΛCDM
Casertano, Stefano; Riess, Adam G.; Yuan, Wenlong +2 more
We present an improved determination of the Hubble constant from Hubble Space Telescope (HST) observations of 70 long-period Cepheids in the Large Magellanic Cloud (LMC). These were obtained with the same WFC3 photometric system used to measure extragalactic Cepheids in the hosts of SNe Ia. Gyroscopic control of HST was employed to reduce overhead…
UNIVERSEMACHINE: The correlation between galaxy growth and dark matter halo assembly from z = 0-10
Conroy, Charlie; Behroozi, Peter; Wechsler, Risa H. +1 more
We present a method to flexibly and self-consistently determine individual galaxies' star formation rates (SFRs) from their host haloes' potential well depths, assembly histories, and redshifts. The method is constrained by galaxies' observed stellar mass functions, SFRs (specific and cosmic), quenched fractions, ultraviolet (UV) luminosity functi…
SIMBA: Cosmological simulations with black hole growth and feedback
Davé, Romeel; Narayanan, Desika; Li, Qi +3 more
We introduce the SIMBA simulations, the next generation of the MUFASA cosmological galaxy formation simulations run with GIZMO's meshless finite mass hydrodynamics. SIMBA includes updates to MUFASA's sub-resolution star formation and feedback prescriptions, and introduces black hole growth via the torque-limited accretion model of Anglés-Alcázar e…
The Carnegie-Chicago Hubble Program. VIII. An Independent Determination of the Hubble Constant Based on the Tip of the Red Giant Branch
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +10 more
We present a new and independent determination of the local value of the Hubble constant based on a calibration of the tip of the red giant branch (TRGB) applied to Type Ia supernovae (SNe Ia). We find a value of H 0 = 69.8 ± 0.8 (±1.1% stat) ± 1.7 (±2.4% sys) km s-1 Mpc-1. The TRGB method is both precise and accur…
Microlensing constraints on primordial black holes with Subaru/HSC Andromeda observations
Oguri, Masamune; More, Surhud; Takada, Masahiro +8 more
Primordial black holes (PBHs) have long been suggested as a viable candidate for the elusive dark matter. The abundance of such PBHs has been constrained using a number of astrophysical observations, except for a hitherto unexplored mass window of MPBH = [10-14, 10-9] solar masses. Here we carry out a dense-cadence…
Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data
Strauss, Michael A.; Wang, Shiang-Yu; Sifón, Cristóbal +34 more
We measure cosmic weak lensing shear power spectra with the Subaru Hyper Suprime-Cam (HSC) survey first-year shear catalog covering 137 deg2 of the sky. Thanks to the high effective galaxy number density of ∼17 arcmin-2, even after conservative cuts such as a magnitude cut of i < 24.5 and photometric redshift cut of 0.3 ≤ …
Star Clusters Across Cosmic Time
Bland-Hawthorn, Joss; Krumholz, Mark R.; McKee, Christopher F.
Star clusters stand at the intersection of much of modern astrophysics: the ISM, gravitational dynamics, stellar evolution, and cosmology. Here, we review observations and theoretical models for the formation, evolution, and eventual disruption of star clusters. Current literature suggests a picture of this life cycle including the following sever…
Mean proper motions, space orbits, and velocity dispersion profiles of Galactic globular clusters derived from Gaia DR2 data
Hilker, M.; Bellini, A.; Baumgardt, H. +1 more
We have derived the mean proper motions and space velocities of 154 Galactic globular clusters and the velocity dispersion profiles of 141 globular clusters based on a combination of Gaia DR2 proper motions with ground-based line-of-sight velocities. Combining the velocity dispersion profiles derived here with new measurements of the internal mass…
Cluster Cosmology Constraints from the 2500 deg2 SPT-SZ Survey: Inclusion of Weak Gravitational Lensing Data from Magellan and the Hubble Space Telescope
Gladders, M. D.; Schrabback, T.; Rest, A. +77 more
We derive cosmological constraints using a galaxy cluster sample selected from the 2500 deg2 SPT-SZ survey. The sample spans the redshift range 0.25 < z < 1.75 and contains 343 clusters with SZ detection significance ξ > 5. The sample is supplemented with optical weak gravitational lensing measurements of 32 clusters with 0.29 …
Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly
Mignard, François; Thévenin, Frédéric; Kervella, Pierre +1 more
Context. The census of stellar and substellar companions of nearby stars is largely incomplete, in particular toward the low-mass brown dwarf and long-period exoplanets. It is, however, fundamentally important in the understanding of the stellar and planetary formation and evolution mechanisms. Nearby stars are particularly favorable targets for h…