Search Publications
Uniform Forward-modeling Analysis of Ultracool Dwarfs. I. Methodology and Benchmarking
Line, Michael R.; Marley, Mark S.; Liu, Michael C. +2 more
We present a forward-modeling framework using the Bayesian inference tool Starfish and cloudless Sonora-Bobcat model atmospheres to analyze low-resolution (R ≈ 80-250) near-infrared (1.0-2.5 µm) spectra of T dwarfs. Our approach infers effective temperatures, surface gravities, metallicities, radii, and masses, and by accounting for uncertai…
Radial structure and formation of the Milky Way disc
Katz, D.; Haywood, M.; Gómez, A. +2 more
Context. The formation of the Galactic disc is an enthusiastically debated issue. Numerous studies and models seek to identify the dominant physical process(es) that shaped its observed properties; for example, satellite accretion, starburst, quenching, gas infall, and stellar radial migration.
Aims: Taking advantage of the improved coverage …
Solar wind turbulence: Connections with energetic particles
Oughton, Sean; Engelbrecht, N. Eugene
For the solar wind, a wealth of observational evidence indicates that turbulence is an important dynamical process for velocity (v), magnetic (b), and other related fluctuations at MHD (fluid) scales. Here we review such observations and turbulence features, including discussion of when wave or turbulence descriptions can (or cannot) explain the o…
Revealing the Structure and Internal Rotation of the Sagittarius Dwarf Spheroidal Galaxy with Gaia and Machine Learning
van der Marel, Roeland P.; Fardal, Mark A.; Sohn, Sangmo Tony +3 more
We present a detailed study of the internal structure and kinematics of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). Using machine-learning techniques, we have combined the information provided by 3300 RR Lyrae stars, more than 2000 spectroscopically observed stars, and the Gaia second data release to derive the full phase space, i.e…
Dust-enshrouded AGNs Can Dominate Host-galaxy-scale Cold Dust Emission
Smith, Howard A.; Rosenthal, Lee J.; McKinney, Jed +4 more
It is widely assumed that long-wavelength infrared (IR) emission from cold dust (T ~ 20-40 K) is a reliable tracer of star formation even in the presence of a bright active galactic nucleus (AGN). Based on radiative transfer (RT) models of clumpy AGN tori, hot dust emission from the torus contributes negligibly to the galaxy spectral energy distri…
Stellar substructures in the periphery of the Magellanic Clouds with the VISTA hemisphere survey from the red clump and other tracers
Sun, Ning-Chen; de Grijs, Richard; Ripepi, Vincenzo +11 more
We study the morphology of the stellar periphery of the Magellanic Clouds in search of substructure using near-infrared imaging data from the Visible and Infrared Survey Telescope for Astronomy Hemisphere Survey. Based on the selection of different stellar populations using the (J - Ks, Ks) colour-magnitude diagram, we confir…
The Tarantula Massive Binary Monitoring. V. R 144: a wind-eclipsing binary with a total mass ≳140 M⊙
Howarth, I. D.; Crowther, P. A.; de Mink, S. E. +21 more
Context. The evolution of the most massive stars and their upper-mass limit remain insufficiently constrained. Very massive stars are characterized by powerful winds and spectroscopically appear as hydrogen-rich Wolf-Rayet (WR) stars on the main sequence. R 144 is the visually brightest WR star in the Large Magellanic Cloud. R 144 was reported to …
Generation of interplanetary type II radio emission
Jebaraj, I. C.; Mann, G.; Poedts, S. +4 more
Context. Coronal mass ejections (CMEs) are eruptive phenomena that can accelerate energetic particles and drive shock waves. The CME-driven shocks propagate from the low corona to interplanetary space. The radio emission that results from fast electrons energised by shock waves are called type II bursts. This radio emission can provide information…
TOI-1634 b: An Ultra-short-period Keystone Planet Sitting inside the M-dwarf Radius Valley
López-Morales, Mercedes; Bieryla, Allyson; Latham, David W. +63 more
Studies of close-in planets orbiting M dwarfs have suggested that the M-dwarf radius valley may be well explained by distinct formation timescales between enveloped terrestrials and rocky planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseo…
ALMA and IRIS Observations of the Solar Chromosphere. I. An On-disk Type II Spicule
Martínez-Sykora, Juan; De Pontieu, Bart; Chintzoglou, Georgios +7 more
We present observations of the solar chromosphere obtained simultaneously with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph. The observatories targeted a chromospheric plage region of which the spatial distribution (split between strongly and weakly magnetized regions) allowed the study of l…