Search Publications
Dynamical Model of the Milky Way Using APOGEE and Gaia Data
Neumayer, Nadine; Rix, Hans-Walter; Cappellari, Michele +2 more
We construct a dynamical model of the Milky Way disk from a data set that combines Gaia EDR3 and APOGEE data throughout galactocentric radii in the range 5.0 kpc ≤ R ≤ 19.5 kpc. We make use of the spherically aligned Jeans anisotropic method to model the stellar velocities and their velocity dispersions. Building upon our previous work, our model …
A Disk and No Signatures of Tidal Distortion in the Galaxy "Lacking" Dark Matter NGC 1052-DF2
Trujillo, Ignacio; Borlaff, Alejandro S.; Monelli, Matteo +2 more
Using ultra-deep imaging (µg = 30.4 mag arcsec-2; 3σ, 10″ × 10″), we probed the surroundings of the first galaxy "lacking" dark matter (DM) KKS2000[04] (NGC 1052-DF2). Signs of tidal stripping in this galaxy would explain its claimed low content of DM. However, we find no evidence of tidal tails. In fact, the galaxy rem…
Split Peas in a Pod: Intra-system Uniformity of Super-Earths and Sub-Neptunes
Winn, Joshua N.; Millholland, Sarah C.
The planets within compact multiplanet systems tend to have similar sizes, masses, and orbital period ratios, like "peas in a pod." This pattern was detected when considering planets with radii between 1 and 4 R⊕. However, these same planets show a bimodal radius distribution, with few planets between 1.5 and 2 R⊕. The smalle…
A New Sample of Warm Extreme Debris Disks from the ALLWISE Catalog
Henning, Thomas; Pál, András; Kinemuchi, Karen +12 more
Extreme debris disks (EDDs) are rare systems with peculiarly large amounts of warm dust that may stem from recent giant impacts between planetary embryos during the final phases of terrestrial planet growth. Here we report on the identification and characterization of six new EDDs. These disks surround F5-G9 type main-sequence stars with ages >…
Molecular Line Observations in Two Dusty Star-forming Galaxies at z = 6.9
Greve, Thomas R.; Phadke, Kedar A.; Aravena, Manuel +18 more
SPT0311-58 is the most massive infrared luminous system discovered so far during the Epoch of Reionization (EoR). In this paper, we present a detailed analysis of the molecular interstellar medium at z = 6.9, through high resolution observations of the CO(6-5), CO(7-6), CO(10-9), [C I](2-1), and p-H2O(21,1 -20,2) l…
Tracking the Evolution of Lithium in Giants Using Asteroseismology: Super-Li-rich Stars Are Almost Exclusively Young Red-clump Stars
Vrard, Mathieu; Campbell, Simon W.; Reddy, Bacham E. +2 more
We report novel observational evidence on the evolutionary status of lithium-rich giant stars by combining asteroseismic and lithium abundance data. Comparing observations and models of the asteroseismic gravity-mode period spacing ΔΠ1, we find that super-Li-rich giants (SLRs, A(Li) > 3.2 dex) are almost exclusively young red-clump (…
Membership Lists for 431 Open Clusters in Gaia DR2 Using Extreme Deconvolution Gaussian Mixture Models
Jaehnig, Karl; Holley-Bockelmann, Kelly; Bird, Jonathan
Open clusters are groups of stars that form at the same time, making them an ideal laboratory to test theories of star formation, stellar evolution, and dynamics in the Milky Way disk. However, the utility of an open cluster can be limited by the accuracy and completeness of its known members. Here, we employ a "top-down" technique, Extreme Deconv…
Kinematics of the Circumgalactic Medium of a z = 0.77 Galaxy from Mg II Tomography
Faucher-Giguère, Claude-André; Sanders, Ryan L.; Stark, Daniel P. +5 more
Galaxy evolution is thought to be driven in large part by the flow of gas between galaxies and the circumgalactic medium (CGM), a halo of metal-enriched gas extending out to ≳100 kpc from each galaxy. Studying the spatial structure of the CGM holds promise for understanding these gas flow mechanisms; however, the common method of using background …
Gaia Gaps and the Physics of Low-mass Stars. I. The Fully Convective Boundary
Jao, Wei-Chun; Feiden, Gregory A.; Skidmore, Khian
The Gaia M-dwarf gap is a significant underdensity of stars observed near MG = 10.2 in a color-magnitude diagram for stars within 200 pc of the Sun. It has been proposed that the gap is the manifestation of structural instabilities within stellar interiors due to nonequilibrium 3He fusion prior to some stars becoming fully co…
A Model for the Coupled Eruption of a Pseudostreamer and Helmet Streamer
Lynch, B. J.; Antiochos, S. K.; Kumar, P. +3 more
A highly important aspect of solar activity is the coupling between eruptions and the surrounding coronal magnetic field topology, which determines the trajectory and morphology of the event and can even lead to sympathetic eruptions from multiple sources. In this paper, we report on a numerical simulation of a new type of coupled eruption, in whi…