Search Publications
Molecular Gas Filaments and Fallback in the Ram Pressure Stripped Coma Spiral NGC 4921
Tonnesen, S.; Smith, R.; Cramer, W. J. +6 more
We investigate the effects of ram pressure on the molecular interstellar medium (ISM) in the disk of the Coma cluster galaxy NGC 4921 via high-resolution CO observations. We present 6″ resolution CARMA CO(1-0) observations of the full disk, and 0"4 resolution Atacama Large Millimeter/submillimeter Array CO(2-1) observations of the leading quadrant…
The Sample of Red Supergiants in 12 Low-mass Galaxies of the Local Group
Yang, Ming; Ren, Yi; Jiang, Biwei +2 more
This work establishes the most complete sample of red supergiants (RSGs) in 12 low-mass galaxies (WLM, IC 10, NGC 147, NGC 185, IC 1613, Leo A, Sextans B, Sextans A, NGC 6822, Pegasus Dwarf, SMC, and LMC) of the Local Group, which forms a solid basis to study the properties of RSGs as well as the star formation rate and initial mass function of th…
Vertical Phase Mixing across the Galactic Disk
Li, Zhao-Yu
By combining the Large Sky Area Multi-object Fiber Spectroscopic Telescope and Gaia data, we investigate the vertical phase mixing across the Galactic disk. Our results confirm the existence of phase space snail shells (or phase spirals) from 6-12 kpc. We find that grouping stars by the guiding radius (Rg), instead of the present radius…
TOI-3362b: A Proto Hot Jupiter Undergoing High-eccentricity Tidal Migration
Triaud, Amaury H. M. J.; Latham, David W.; Quinn, Samuel N. +39 more
High-eccentricity tidal migration is a possible way for giant planets to be placed in short-period orbits. If this happens often, one would expect to catch proto hot Jupiters on highly elliptical orbits undergoing high-eccentricity tidal migration. As of yet, few such systems have been discovered. Here, we introduce TOI-3362b (TIC-464300749b), an …
The Geometry of Cold, Metal-enriched Gas around Galaxies at z ∼ 1.2
van Dokkum, Pieter; York, Donald G.; Chisholm, John +10 more
We present the first results from a Hubble Space Telescope Wide Field Camera 3/Infrared program, which obtained direct imaging and grism observations of galaxies near quasar sightlines with a high frequency of uncorrelated foreground Mg II absorption. These highly efficient observations targeted 54 Mg II absorbers along the line of sight to nine q…
Evidence for Radial Expansion at the Core of the Orion Complex with Gaia EDR3
Meingast, Stefan; Alves, João; Zucker, Catherine +6 more
We present a phase-space study of two stellar groups located at the core of the Orion Complex: Briceño-1 and Orion Belt Population-near (OBP-near). We identify the groups with the unsupervised clustering algorithm, Shared Nearest Neighbor (SNN), which previously identified 12 new stellar substructures in the Orion Complex. For each of the two grou…
Velocity Dispersion of the GD-1 Stellar Stream
Naidu, Rohan P.; Bonaca, Ana; Gialluca, Megan T.
Tidally dissolved globular clusters form thin stellar streams that preserve a historical record of their past evolution. We report a radial velocity dispersion of 2.1 ± 0.3 km s-1 in the GD-1 stellar stream using a sample of 43 spectroscopically confirmed members. The GD-1 velocity dispersion is constant over the surveyed ≈15° span of t…
Abundance Patterns of α and Neutron-capture Elements in the Helmi Stream
Chiappini, Cristina; Limberg, Guilherme; Rossi, Silvia +6 more
We identified eight additional stars as members of the Helmi stream (HStr) in the combined GALAH+ DR3 and Gaia EDR3 catalog. By consistently reevaluating claimed members from the literature, we consolidate a sample of 22 HStr stars with parameters determined from high-resolution spectroscopy and spanning a considerably wider (by ∼0.5 dex) metallic…
Alfvénic Perturbations in a Sunspot Chromosphere Linked to Fractionated Plasma in the Corona
Stangalini, Marco; Brooks, David H.; Baker, Deborah +7 more
In this study, we investigate the spatial distribution of highly varying plasma composition around one of the largest sunspots of solar cycle 24. Observations of the photosphere, chromosphere, and corona are brought together with magnetic field modeling of the sunspot in order to probe the conditions that regulate the degree of plasma fractionatio…
An Energy Inventory of Tidal Disruption Events
Ramirez-Ruiz, Enrico; Mockler, Brenna
Tidal disruption events (TDEs) offer a unique opportunity to study a single supermassive black hole (SMBH) under feeding conditions that change over timescales of days to months. However, the primary mechanism for generating luminosity during the flares remains debated. Despite the increasing number of observed TDEs, it is unclear whether most of …