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Hubble Space Telescope Trigonometric Parallax of Polaris B, Companion of the Nearest Cepheid
Schaefer, Gail H.; Nelan, Edmund P.; Bond, Howard E. +2 more
Polaris, the nearest and brightest Cepheid, is a potential anchor point for the Leavitt period-luminosity relation. However, its distance is a matter of contention, with recent advocacy for a parallax of ∼10 mas, in contrast with the Hipparcos measurement of 7.54 ± 0.11 mas. We report an independent trigonometric parallax determination, using the …
High-frequency Spicule Oscillations Generated via Mode Conversion
Yokoyama, Takaaki; Shoda, Munehito
Spicule oscillations involve high-frequency components with a typical period approximately corresponding to 40-50 s. The typical timescale of the photospheric oscillation is a few minutes, and thus, the origin of this high-frequency component is not trivial. In this study, a one-dimensional numerical simulation is performed to demonstrate that the…
Spatially Offset Active Galactic Nuclei. III. Discovery of Late-stage Galaxy Mergers with the Hubble Space Telescope
Greene, Jenny E.; Comerford, Julia M.; Barrows, R. Scott
Galaxy pairs with separations of only a few kiloparsecs represent important stages in the merger-driven growth of supermassive black holes (SMBHs). However, such mergers are difficult to identify observationally due to the correspondingly small angular scales. In Paper I we presented a method of finding candidate kiloparsec-scale galaxy mergers th…
Dependence of Coronal Loop Temperature on Loop Length and Magnetic Field Strength
Velli, M.; Ugarte-Urra, I.; Dahlburg, R. B. +2 more
The temperature characteristics of solar coronal loops over a wide range of lengths and magnetic field strengths are investigated by means of numerical simulations. A very high correlation between magnetic field strength (B 0) and maximum temperature (T max) is found. Shorter loops rooted at stronger fields are those that rea…
Ensemble Properties of the White Dwarf Population of the Old, Solar Metallicity Open Star Cluster Messier 67
Kilic, Mukremin; Bellini, A.; Bolte, Michael +4 more
White dwarfs (WDs) are excellent forensic tools for studying end-of-life issues surrounding low- and intermediate-mass stars, and the old, solar metallicity open star cluster Messier 67 is a proven laboratory for the study of stellar evolution for solar-type stars. In this paper, we present a detailed spectroscopic study of brighter (M g
Measuring Model-independent Masses and Radii of Single-lined Eclipsing Binaries: Analytic Precision Estimates
Stassun, Keivan G.; Stevens, Daniel J.; Gaudi, B. Scott
We derive analytic estimates for the ability with which one can obtain precise, empirical stellar masses and radii via single-lined eclipsing binaries (EBs) in the era of Gaia and TESS. Including stars that host transiting substellar companions, such single-lined EBs already number in the hundreds from ground-based transit surveys and will compris…
X-Ray Variability from the Ultraluminous Black Hole Candidate X-Ray Binary in the Globular Cluster RZ 2109
Kundu, Arunav; Dage, Kristen C.; Zepf, Stephen E. +3 more
We present the results of long-term monitoring of the X-ray emission from the ultraluminous X-ray source XMMU J122939.9+075333 in the extragalactic globular cluster RZ2109. The combination of the high X-ray luminosity, short-term X-ray variability, X-ray spectrum, and optical emission suggests that this system is likely an accreting black hole in …
The Cosmic Web around the Brightest Galaxies during the Epoch of Reionization
Trenti, Michele; Mutch, Simon J.; Ren, Keven
The most luminous galaxies at high redshift are generally considered to be hosted in massive dark-matter halos of comparable number density, hence residing at the center of over-densities/protoclusters. We assess the validity of this assumption by investigating the clustering around the brightest galaxies populating the cosmic web at redshift z ∼ …
Noble Gas Abundance Ratios Indicate the Agglomeration of 67P/Churyumov-Gerasimenko from Warmed-up Ice
Wurz, P.; Lunine, J. I.; Danger, G. +8 more
The origin of cometary volatiles remains a major open question in planetary science. Comets may have either agglomerated from crystalline ices condensed in the protosolar nebula (PSN) or from amorphous ice originating from the molecular cloud and interstellar medium. Here, based on the recent argon, krypton, and xenon measurements performed by the…
The Spectral Energy Distribution of the Hyperluminous, Hot Dust-obscured Galaxy W2246-0526
Shu, Xinwen; Knudsen, Kirsten K.; Fan, Lulu +1 more
Hot dust-obscured galaxies (Hot DOGs) are a luminous, dust-obscured population recently discovered in the WISE All-Sky survey. Multiwavelength follow-up observations suggest that they are mainly powered by accreting supermassive black holes (SMBHs), lying in dense environments, and being in the transition phase between extreme starburst and UV-bri…