Search Publications
Alpha-Proton Differential Flow of the Young Solar Wind: Parker Solar Probe Observations
Bale, S. D.; Allen, R. C.; Raouafi, N. E. +5 more
The velocity of alpha particles relative to protons can vary depending on the solar wind type and distance from the Sun. Measurements from the previous spacecraft provided the alpha-proton differential velocities down to 0.3 au. The Parker Solar Probe (PSP) now enables insights into differential flows of the newly accelerated solar wind closer to …
Discovery of Eight "Main-sequence Radio Pulse Emitters" Using the GMRT: Clues to the Onset of Coherent Radio Emission in Hot Magnetic Stars
Neiner, Coralie; Wade, Gregg A.; Chandra, Poonam +6 more
Main-sequence radio pulse emitters (MRPs) are magnetic early-type stars from which periodic radio pulses, produced via electron cyclotron maser emission (ECME), are observed. Despite the fact that these stars can naturally offer suitable conditions for triggering ECME, only seven such stars have been reported so far within a span of more than two …
A Tilt in the Dark Matter Halo of the Galaxy
Conroy, Charlie; Ting, Yuan-Sen; Johnson, Benjamin D. +9 more
Recent observations of the stellar halo have uncovered the debris of an ancient merger, Gaia-Sausage-Enceladus (GSE), estimated to have occurred ≳8 Gyr ago. Follow-up studies have associated GSE with a large-scale tilt in the stellar halo that links two well-known stellar overdensities in diagonally opposing octants of the Galaxy (the Hercules-Aqu…
GOALS-JWST: Hidden Star Formation and Extended PAH Emission in the Luminous Infrared Galaxy VV 114
Frayer, D. T.; Inami, Hanae; Böker, Torsten +32 more
James Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) images of the luminous infrared (IR) galaxy VV 114 are presented. This redshift ~0.020 merger has a western component (VV 114W) rich in optical star clusters and an eastern component (VV 114E) hosting a luminous mid-IR nucleus hidden at UV and optical wavelengths by dust lanes. With …
Diagnosing FU Ori-like Sources: The Parameter Space of Viscously Heated Disks in the Optical and Near-infrared
Herczeg, Gregory J.; Jose, Jessy; Johnstone, Doug +8 more
FU Ori-type objects (FUors) are decades-long outbursts of accretion onto young stars that are strong enough to viscously heat disks so that the disk outshines the central star. We construct models for FUor objects by calculating emission components from a steady-state viscous accretion disk, a passively-heated dusty disk, magnetospheric accretion …
AGN Selection Methods Have Profound Impacts on the Distributions of Host-galaxy Properties
Giavalisco, Mauro; Kirkpatrick, Allison; Ji, Zhiyuan +4 more
We present a comparative study of X-ray and IR active galactic nuclei (AGNs) at z ≈ 2 to highlight the important AGN selection effects on the distributions of host-galaxy properties. Compared with non-AGN star-forming galaxies (SFGs) on the main sequence, X-ray AGNs have similar median star formation (SF) properties, but their incidence (q AG…
An Atmospheric Retrieval of the Brown Dwarf Gliese 229B
Faherty, Jacqueline K.; Calamari, Emily; Burningham, Ben +6 more
We present results from an atmospheric retrieval analysis of Gl 229B using the Brewster retrieval code. We find the best fit model to be cloud-free, consistent with the T dwarf retrieval work of Line et al.; Zalesky et al. and Gonzales et al. Fundamental parameters (mass, radius, log(L Bol /L Sun), log(g)) determined from our…
Cleaning Our Hazy Lens: Exploring Trends in Transmission Spectra of Warm Exoplanets
Fortney, Jonathan J.; Zhang, Xi; Thorngren, Daniel +4 more
Relatively little is understood about the atmospheric composition of temperate to warm exoplanets (equilibrium temperature T eq < 1000 K), as many of them are found to have uncharacteristically flat transmission spectra. Their flattened spectra are likely due to atmospheric opacity sources such as planet-wide photochemical hazes and …
From Naked Spheroids to Disky Galaxies: How Do Massive Disk Galaxies Shape Their Morphology?
Barro, Guillermo; Pérez-González, Pablo G.; Costantin, Luca +9 more
We investigate the assembly history of massive disk galaxies and describe how they shape their morphology through cosmic time. Using SHARDS and HST data, we modeled the surface brightness distribution of 91 massive galaxies at redshift 0.14 < z ≤ 1 in the wavelength range 0.5-1.6 µm, deriving the uncontaminated spectral energy distributio…
About Metallicity Variations in the Local Galactic Interstellar Medium
Méndez-Delgado, J. E.; Arellano-Córdova, K. Z.; García-Rojas, J. +1 more
In this paper we discuss and confront recent results on metallicity variations in the local interstellar medium, obtained from observations of H II regions and neutral clouds of the Galactic thin disk, and compare them with recent high-quality metallicity determinations of other tracers of the chemical composition of the interstellar medium as B-t…