Search Publications
The mass of our Galaxy from satellite proper motions in the Gaia era
Fritz, T. K.; Di Cintio, A.; Battaglia, G. +2 more
We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass of the Milky Way using the scale-free mass estimator of Watkins et al. (2010). We first determine the anisotropy parameter β, and the tracer satellites' radial density index γ to be β = $-0.67^{+0.45}_{-0.62}$ and γ = 2.11 ± 0.23. When we exclude possible former…
Spectral Signatures of Chromospheric Condensation in a Major Solar Flare
Allred, Joel; Graham, David R.; Zangrilli, Luca +3 more
We study the evolution of chromospheric line and continuum emission during the impulsive phase of the X-class SOL2014-09-10T17:45 solar flare. We extend previous analyses of this flare to multiple chromospheric lines of Fe I, Fe II, Mg II, C I, and Si II observed with the Interface Region Imaging Spectrograph, combined with radiative-hydrodynamica…
Unveiling cloudy exoplanets: the influence of cloud model choices on retrieval solutions
Barstow, Joanna K.
In recent years, it has become clear that a substantial fraction of transiting exoplanets have some form of aerosol present in their atmospheres. Transit spectroscopy - mostly of hot Jupiters, but also of some smaller planets - has provided evidence for this, in the form of steep downward slopes from blue to red in the optical part of the spectrum…
First detection of stacked X-ray emission from cosmic web filaments
Aghanim, N.; Douspis, M.; Malavasi, N. +2 more
We report the first statistical detection of X-ray emission from cosmic web filaments in ROSAT data. We selected 15 165 filaments at 0.2 < z < 0.6 ranging from 30 Mpc to 100 Mpc in length, identified in the Sloan Digital Sky Survey survey. We stacked the X-ray count-rate maps from ROSAT around the filaments, excluding resolved galaxy groups …
Empirical bolometric correction coefficients for nearby main-sequence stars in the Gaia era
Bakış, V.; Eker, Z.; Soydugan, F. +6 more
Nearby detached double-lined eclipsing binaries with most accurate data were studied and 290 systems were found with at least one main-sequence component having a metallicity of 0.008 ≤ Z ≤ 0.040. Stellar parameters, light ratios, Gaia Data Release 2 trigonometric parallaxes, extinctions and/or reddening were investigated and only 206 systems were…
The frequency of gaseous debris discs around white dwarfs
Hollands, Mark; Pelisoli, Ingrid; Breedt, Elmé +5 more
A total of 1-3 per cent of white dwarfs are orbited by planetary dusty debris detectable as infrared emission in excess above the white dwarf flux. In a rare subset of these systems, a gaseous disc component is also detected via emission lines of the Ca II 8600 Å triplet, broadened by the Keplerian velocity of the disc. We present the first statis…
New white dwarf envelope models and diffusion. Application to DQ white dwarfs
Kepler, S. O.; Koester, D.; Irwin, A. W.
Context. Recent studies of the atmospheres of carbon-rich (DQ) white dwarfs have demonstrated the existence of two different populations that are distinguished by the temperature range, but more importantly, by the extremely high masses of the hotter group. The classical DQ below 10 000 K are well understood as the result of dredge-up of carbon by…
The Regulation of Galaxy Growth along the Size-Mass Relation by Star Formation, as Traced by Hα in KMOS3D Galaxies at 0.7 ≲ z ≲ 2.7
Übler, Hannah; van Dokkum, Pieter; Momcheva, Ivelina +24 more
We present half-light sizes measured from Hα emission tracing star formation in 281 star-forming galaxies from the KMOS3D survey at 0.7≲ z ≲ 2.7. Sizes are derived by fitting 2D exponential disk models, with bootstrap errors averaging 20%. Hα sizes are a median (mean) of 1.19 (1.26) times larger than those of the stellar continuum—which…
An Information Theoretic Framework for Classifying Exoplanetary System Architectures
Fabrycky, Daniel C.; Gilbert, Gregory J.
We propose several descriptive measures to characterize the arrangements of planetary masses, periods, and mutual inclinations within exoplanetary systems. These measures are based on complexity theory and capture the global, system-level trends of each architecture. Our approach considers all planets in a system simultaneously, facilitating both …
TRAPPIST-1: Global results of the Spitzer Exploration Science Program Red Worlds
Queloz, D.; Agol, E.; Delrez, L. +18 more
Context. With more than 1000 h of observation from Feb. 2016 to Oct. 2019, the Spitzer Exploration Program Red Worlds (ID: 13067, 13175 and 14223) exclusively targeted TRAPPIST-1, a nearby (12 pc) ultracool dwarf star, finding that it is orbited by seven transiting Earth-sized planets. At least three of these planets orbit within the classical hab…