Search Publications
Fast winds drive slow shells: a model for the circumgalactic medium as galactic wind-driven bubbles
Thompson, Todd A.; Weinberg, David H.; Quataert, Eliot +1 more
Successful models of the low-redshift circumgalactic medium (CGM) must account for (1) a large amount of gas, (2) relatively slow gas velocities, (3) a high degree of metal enrichment, (4) the similar absorption properties around both star-forming and passive galaxies, and (5) the observationally inferred temperature and densities of the CGM gas. …
Solar Wind Induced Waves in the Skies of Mars: Ionospheric Compression, Energization, and Escape Resulting From the Impact of Ultralow Frequency Magnetosonic Waves Generated Upstream of the Martian Bow Shock
Zhang, Tielong; Futaana, Yoshifumi; Mazelle, Christian +12 more
Using data from the National Aeronautics and Space Administration Mars Atmosphere and Voltatile EvolutioN and the European Space Agency Mars Express spacecraft, we show that transient phenomena in the foreshock and solar wind can directly inject energy into the ionosphere of Mars. We demonstrate that the impact of compressive ultralow frequency wa…
Astrometric Limits on the Stochastic Gravitational Wave Background
Darling, Jeremy; Truebenbach, Alexandra E.; Paine, Jennie
The canonical methods for gravitational wave detection are ground- and space-based laser interferometry, pulsar timing, and polarization of the cosmic microwave background. But as has been suggested by numerous investigators, astrometry offers an additional path to gravitational wave detection. Gravitational waves deflect light rays of extragalact…
On the kinematics of a runaway Be star population
Evans, N. W.; Boubert, D.
We explore the hypothesis that B-type emission-line stars (Be stars) have their origin in mass-transfer binaries by measuring the fraction of runaway Be stars. We assemble the largest-to-date catalogue of 632 Be stars with 6D kinematics, exploiting the precise astrometry of the Tycho-Gaia Astrometric Solution from the first Gaia data release. Usin…
A direct calibration of thtae IRX-β relation in Lyman-break Galaxies at z = 3-5
Scott, D.; McLure, R. J.; Dunlop, J. S. +17 more
We use a sample of 4209 Lyman-break galaxies (LBGs) at z ≃ 3, 4, and 5 in the UKIRT Infrared Deep Sky Survey Ultra Deep Survey field to investigate the relationship between the observed slope of the stellar continuum emission in the ultraviolet, β, and the thermal dust emission, as quantified via the so-called 'infrared excess' (IRX ≡ LIR/LUV). Th…
Cosmological constraints and comparison of viable f (R ) models
Nesseris, Savvas; Pérez-Romero, Judit
In this paper we present cosmological constraints on several well-known f (R ) models, but also on a new class of models that are variants of the Hu-Sawicki one of the form f (R )=R -2/Λ 1 +b y (R ,Λ ) , that interpolate between the cosmological constant model and a matter dominated universe for different values of the parameter b , which is usual…
The Gaia DR2 view of the Gamma Velorum cluster: resolving the 6D structure
Fedele, D.; Franciosini, E.; Randich, S. +4 more
Gaia-ESO Survey observations of the young Gamma Velorum cluster led to the discovery of two kinematically distinct populations, Gamma Vel A and B, respectively, with population B extended over several square degrees in the Vela OB2 association. Using the Gaia DR2 data for a sample of high-probability cluster members, we find that the two populatio…
Rapid Buildup of a Magnetic Flux Rope during a Confined X2.2 Class Flare in NOAA AR 12673
Wang, Yuming; Liu, Lijuan; Cui, Jun +3 more
Magnetic flux ropes (MFRs) are believed to be the core structure in solar eruptions; nevertheless, their formation remains intensely debated. Here we report a rapid buildup process of an MFR system during a confined X2.2 class flare occurred on 2017 September 6 in NOAA active region (AR) 12673, three hours after which the structure erupted to a ma…
GAMA/H-ATLAS: the local dust mass function and cosmic density as a function of galaxy type - a benchmark for models of galaxy evolution
Wang, L.; Baes, M.; Dunne, L. +25 more
We present the dust mass function (DMF) of 15 750 galaxies with redshift z < 0.1, drawn from the overlapping area of the GAMA and H-ATLAS surveys. The DMF is derived using the density corrected Vmax method, where we estimate Vmax using: (i) the normal photometric selection limit (pVmax) and (ii) a bivariate brig…
CLUMP-3D: Testing ΛCDM with Galaxy Cluster Shapes
Zitrin, Adi; Umetsu, Keiichi; Meneghetti, Massimo +5 more
The ΛCDM model of structure formation makes strong predictions on the concentration and shape of dark matter (DM) halos, which are determined by mass accretion processes. Comparison between predicted shapes and observations provides a geometric test of the ΛCDM model. Accurate and precise measurements needs a full three-dimensional (3D) analysis o…