Search Publications
Gastro Library. I. The Simulated Chemodynamical Properties of Several Gaia-Sausage-Enceladus-like Stellar Halos
Laporte, Chervin F. P.; Debattista, Victor P.; Amarante, João A. S. +2 more
The Milky Way (MW) stellar halo contains relics of ancient mergers that tell the story of our galaxy's formation. Some of them are identified due to their similarity in energy, actions, and chemistry, referred to as the "chemodynamical space," and are often attributed to distinct merger events. It is also known that our galaxy went through a signi…
Probing the Physics of the Solar Atmosphere with the Multi-slit Solar Explorer (MUSE). I. Coronal Heating
Matsumoto, Takuma; Polito, Vanessa; Golub, Leon +24 more
The Multi-slit Solar Explorer (MUSE) is a proposed mission composed of a multislit extreme ultraviolet (EUV) spectrograph (in three spectral bands around 171 Å, 284 Å, and 108 Å) and an EUV context imager (in two passbands around 195 Å and 304 Å). MUSE will provide unprecedented spectral and imaging diagnostics of the solar corona at high spatial …
The pattern speed of the Milky Way bar/bulge from VIRAC and Gaia
Gerhard, Ortwin; Clarke, Jonathan P.
We compare distance resolved, absolute proper motions in the Milky Way bar/bulge region to a grid of made-to-measure dynamical models with well-defined pattern speeds. The data are obtained by combining the relative VVV InfraRed Astrometric Catalogue (VIRAC) v1 proper motions with the Gaia Data Release 2 absolute reference frame. We undertake a co…
Exploring the AGN-Ram Pressure Stripping Connection in Local Clusters
Fritz, Jacopo; Vulcani, Benedetta; Poggianti, Bianca M. +8 more
Ram pressure stripping (RPS) by the intracluster medium is one of the most advocated mechanisms that affect the properties of cluster galaxies. A recent study based on a small sample has found that many galaxies showing strong signatures of RPS also possess an active galactic nucleus (AGN), suggesting a possible correlation between the two phenome…
How Many Elements Matter?
Ting, Yuan-Sen; Weinberg, David H.
Some studies of stars' multielement abundance distributions suggest at least 5-7 significant dimensions, but others show that many elemental abundances can be predicted to high accuracy from [Fe/H] and [Mg/Fe] (or [Fe/H] and age) alone. We show that both propositions can be, and are, simultaneously true. We adopt a machine-learning technique known…
Theory of Cosmic Ray Transport in the Heliosphere
Rankin, J. S.; Potgieter, M. S.; Ruffolo, D. +6 more
Modelling the transport of cosmic rays (CRs) in the heliosphere represents a global challenge in the field of heliophysics, in that such a study, if it were to be performed from first principles, requires the careful modelling of both large scale heliospheric plasma quantities (such as the global structure of the heliosphere, or the heliospheric m…
Extremely Low Mass Ratio Contact Binaries. I. The First Photometric and Spectroscopic Investigations of Ten Systems
Li, Kai; Gao, Xing; Chen, Xu +4 more
The photometric and spectroscopic investigations of ten contact binaries were presented for the first time. It is discovered that the mass ratios of all the ten targets are smaller than 0.15, they are extremely low mass ratio contact binaries. Seven of them are deep contact binaries, two are medium contact binaries, while only one is a shallow con…
No Evidence for Axions from Chandra Observation of the Magnetic White Dwarf RE J0317-853
Safdi, Benjamin R.; Dessert, Christopher; Long, Andrew J.
Axions with couplings ga γ γ∼few ×10-11 GeV-1 to electromagnetism may resolve a number of astrophysical anomalies, such as unexpected ∼TeV transparency, anomalous stellar cooling, and x-ray excesses from nearby neutron stars. We show, however, that such axions are severely constrained by the nonobservation of x ray…
Systematic Errors as a Source of Mass Discrepancy in Black Hole Microlensing Event OGLE-2011-BLG-0462
Udalski, Andrzej; Gould, Andrew; Mróz, Przemek
Two independent groups reported the discovery of an isolated dark stellar remnant in the microlensing event OGLE-2011-BLG-0462 based on photometric ground-based observations coupled with astrometric measurements taken with the Hubble Space Telescope. These two analyses yielded discrepant mass measurements, with the first group reporting that the l…
The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence for a Cloud-free Primordial Atmosphere and Constraints on Starspot Contamination
Désert, Jean-Michel; Rackham, Benjamin V.; Morley, Caroline V. +10 more
Orbiting an M dwarf 12 pc away, the transiting exoplanet GJ 1132b is a prime target for transmission spectroscopy. With a mass of 1.7 M ⊕ and radius of 1.1 R ⊕, GJ 1132b's bulk density indicates that this planet is rocky. Yet with an equilibrium temperature of 580 K, GJ 1132b may still retain some semblance of an atmosphere. …