Search Publications
Tidal Effects on the Radial Velocities of V723 Mon: Additional Evidence for a Dark 3 M⊙ Companion
Hirano, Teruyuki; Masuda, Kento
Jayasinghe et al. identified a dark ≈3 M⊙ companion on a nearly edge-on ≈60 day orbit around the red giant star V723 Monoceros as a black hole candidate in the mass gap. This scenario was shown to explain most of the data presented by Jayasinghe et al., except for periodic radial velocity (RV) residuals from the circular Keplerian model…
Relation of Microstreams in the Polar Solar Wind to Switchbacks and Coronal X-Ray Jets
Neugebauer, Marcia; Sterling, Alphonse C.
Ulysses data obtained at high solar latitudes during periods of minimum solar activity in 1994 and 2007 are examined to determine the relation between velocity structures called microstreams and folds in the magnetic field called switchbacks. A high correlation is found. The possibility of velocity peaks in microstreams originating from coronal X-…
The Thermal Sunyaev-Zel'dovich Effect from Massive, Quiescent 0.5 ≤ z ≤ 1.5 Galaxies
Cohen, Seth; Scannapieco, Evan; Mauskopf, Philip +5 more
We use combined South Pole Telescope (SPT)+Planck temperature maps to analyze the circumgalactic medium (CGM) encompassing 138,235 massive, quiescent 0.5 ≤ z ≤ 1.5 galaxies selected from data from the Dark Energy Survey (DES) and Wide-Field Infrared Survey Explorer (WISE). Images centered on these galaxies were cut from the 1.85 arcmin resolution …
Cosmological Constraints from Galaxy Cluster Sparsity, Cluster Gas Mass Fraction, and Baryon Acoustic Oscillation Data
Sereno, Mauro; Ettori, Stefano; Corasaniti, Pier-Stefano
In recent years, the availability of large, complete cluster samples has enabled numerous cosmological parameter inference analyses using cluster number counts. These have provided constraints on the cosmic matter density Ωm and the amplitude of matter density fluctuations σ8 alternative to that obtained from other standard p…
The First Dynamical Mass Determination of a Nitrogen-rich Wolf-Rayet Star Using a Combined Visual and Spectroscopic Orbit
Monnier, John D.; Lanthermann, Cyprien; Anugu, Narsireddy +11 more
We present the first visual orbit for the nitrogen-rich Wolf-Rayet binary, WR 133 (WN5o + O9I), based on observations made with the CHARA Array and the MIRC-X combiner. This orbit represents the first visual orbit for a WN star and only the third Wolf-Rayet star with a visual orbit. The orbit has a period of 112.8 days, a moderate eccentricity of …
Sympathetic Filament Eruptions within a Fan-spine Magnetic System
Shen, Yuandeng; Zhou, Chengrui; Zhou, Xinping +3 more
It is unclear whether successive filament eruptions at different sites within a short time interval are physically connected or not. Here, we present the observations of successive eruptions of a small and a large filament in a tripolar magnetic field region whose coronal magnetic field showed as a fan-spine magnetic system. By analyzing the multi…
Far-Infrared Line Diagnostics: Improving N/O Abundance Estimates for Dusty Galaxies
Lamarche, C.; Stacey, G. J.; Higdon, J. +8 more
The nitrogen-to-oxygen (N/O) abundance ratio is an important diagnostic of galaxy evolution because the ratio is closely tied to the growth of metallicity and the star formation history in galaxies. Estimates for the N/O are traditionally made with optical lines that could suffer from extinction and excitation effects, so the N/O is arguably measu…
EPIC 228782059: Asteroseismology of What Could Be the Coolest Pulsating Helium-atmosphere White Dwarf (DBV) Known
Hermes, J. J.; Fu, J. -N.; Vanderbosch, Zachary P. +5 more
We present analysis of a new pulsating helium-atmosphere (DB) white dwarf, EPIC 228782059, discovered from 55.1 days of K2 photometry. The long-duration, high-quality light curves reveal 11 independent dipole and quadruple modes, from which we derive a rotational period of 34.1 ± 0.4 hr for the star. An optimal model is obtained from a series of g…
Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy
Huang, Yang; Chang, Jiang; Zhang, Huawei +5 more
In this Letter, we report the discovery of an intriguing hypervelocity star (HVS; J1443+1453) candidate that is probably from the Sagittarius Dwarf Spheroidal galaxy (Sgr dSph). The star is an old and very metal-poor low-mass main-sequence turn-off star (age ∼14.0 Gyr and [Fe/H] = -2.23 dex) and has a total velocity of ${559.01}_{-87.40}^{+135.07}…
High-frequency Wave Power Observed in the Solar Chromosphere with IBIS and ALMA
Kowalski, Adam F.; Cranmer, Steven R.; Reardon, Kevin P. +3 more
We present observational constraints on the chromospheric heating contribution from acoustic waves with frequencies between 5 and 50 mHz. We use observations from the Dunn Solar Telescope in New Mexico, complemented with observations from the Atacama Large Millimeter Array collected on 2017 April 23. The properties of the power spectra of the vari…