Search Publications
Magnitude and direction of the local interstellar magnetic field inferred from Voyager 1 and 2 interstellar data and global heliospheric model
Izmodenov, Vladislav V.; Alexashov, Dmitry B.
In this Letter, we provide constraints on the direction and magnitude of the pristine (i.e., unperturbed by the interaction with the Sun) local interstellar magnetic field. The constraints are based on analysis of the interstellar magnetic field components at the heliopause measured by magnetometer instruments on board Voyager 1 and 2 spacecraft. …
Metallicity and α-Element Abundance Gradients along the Sagittarius Stream as Seen by APOGEE
Cohen, Roger E.; Bizyaev, Dmitry; Brownstein, Joel R. +27 more
Using 3D positions and kinematics of stars relative to the Sagittarius (Sgr) orbital plane and angular momentum, we identify 166 Sgr stream members observed by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) that also have Gaia DR2 astrometry. This sample of 63/103 stars in the Sgr trailing/leading arm is combined with an APOGE…
The ALMA Spectroscopic Survey in the HUDF: The Cosmic Dust and Gas Mass Densities in Galaxies up to z ∼ 3
Carilli, Chris; Inami, Hanae; Smail, Ian +24 more
Using the deepest 1.2 mm continuum map to date in the Hubble Ultra Deep Field, which was obtained as part of the ALMA Spectroscopic Survey (ASPECS) large program, we measure the cosmic density of dust and implied gas (H2+H I) mass in galaxies as a function of look-back time. We do so by stacking the contribution from all H-band selected…
The Tarantula Massive Binary Monitoring. III. Atmosphere analysis of double-lined spectroscopic systems
Lennon, D. J.; de Mink, S. E.; de Koter, A. +17 more
Context. Accurate stellar parameters of individual objects in binary systems are essential to constrain the effects of binarity on stellar evolution. These parameters serve as a prerequisite to probing existing and future theoretical evolutionary models.
Aims: We aim to derive the atmospheric parameters of the 31 double-lined spectroscopic bi…
Evidence of a dynamically evolving Galactic warp
Bailer-Jones, C. A. L.; Fouesneau, M.; Andrae, R. +5 more
In a cosmological setting, the disk of a galaxy is expected to continuously experience gravitational torques and perturbations from a variety of sources, which can cause the disk to wobble, flare and warp1,2. Specifically, the study of galactic warps and their dynamic nature could reveal key information on the formation history of galax…
Multi-gigayear White Dwarf Cooling Delays from Clustering-enhanced Gravitational Sedimentation
Cheng, Sihao; Bildsten, Lars; Schwab, Josiah +1 more
Cooling white dwarfs (WDs) can yield accurate ages when theoretical cooling models fully account for the physics of the dense plasma of WD interiors. We use MESA to investigate cooling models for a set of massive and ultramassive WDs (0.9-1.3 ${M}_{\odot }$ ) for which previous models have failed to match kinematic age indicators based on Gaia DR2…
Deflating Super-puffs: Impact of Photochemical Hazes on the Observed Mass-Radius Relationship of Low-mass Planets
Zhang, Xi; Gao, Peter
The observed mass-radius relationship of low-mass planets informs our understanding of their composition and evolution. Recent discoveries of low-mass, large-radius objects ("super-puffs") have challenged theories of planet formation and atmospheric loss, as their high inferred gas masses make them vulnerable to runaway accretion and hydrodynamic …
Hydrodynamic Response of the Intergalactic Medium to Reionization
Trac, Hy; Cain, Christopher; D'Aloisio, Anson +2 more
The intergalactic medium is expected to clump on scales down to ${10}^{4}\mbox{--}{10}^{8}$ M⊙ before the onset of reionization. The impact of these small-scale structures on reionization is poorly understood despite the modern understanding that gas clumpiness limits the growth of ${\rm{H}}\,{\rm{II}}$ regions. We use a suite of radiat…
Discovery of a Gamma-Ray Black Widow Pulsar by GPU-accelerated Einstein@Home
Dhillon, V. S.; Freire, P.; Camilo, F. +39 more
We report the discovery of 1.97 ms period gamma-ray pulsations from the 75 minute orbital-period binary pulsar now named PSR J1653-0158. The associated Fermi Large Area Telescope gamma-ray source 4FGL J1653.6-0158 has long been expected to harbor a binary millisecond pulsar. Despite the pulsar-like gamma-ray spectrum and candidate optical/X-ray as…
The Cosmic Ultraviolet Baryon Survey (CUBS) - I. Overview and the diverse environments of Lyman limit systems at z < 1
Weiner, Benjamin J.; Faucher-Giguère, Claude-André; Johnson, Sean D. +19 more
We present initial results from the Cosmic Ultraviolet Baryon Survey (CUBS). CUBS is designed to map diffuse baryonic structures at redshift z ≲ 1 using absorption-line spectroscopy of 15 UV-bright QSOs with matching deep galaxy survey data. CUBS QSOs are selected based on their NUV brightness to avoid biases against the presence of intervening Ly…