Search Publications
Recurrent Activity from Active Asteroid (248370) 2005 QN173: A Main-belt Comet
Chandler, Colin Orion; Trujillo, Chadwick A.; Hsieh, Henry H.
We present archival observations of main-belt asteroid (248370) 2005 QN173 (also designated 433P) that demonstrate this recently discovered active asteroid (a body with a dynamically asteroidal orbit displaying a tail or coma) has had at least one additional apparition of activity near perihelion during a prior orbit. We discovered evid…
Revisiting Attenuation Curves: The Case of NGC 3351
Grebel, Eva K.; Östlin, Göran; Smith, Linda J. +14 more
Multiwavelength images from the far-UV (∼0.15 µm) to the submillimeter of the central region of the galaxy NGC 3351 are analyzed to constrain its stellar populations and dust attenuation. Despite hosting a ∼1 kpc circumnuclear starburst ring, NGC 3351 deviates from the IRX-β relation, the relation between the infrared-to-UV luminosity ratio …
An Observational Study of a "Rosetta Stone" Solar Eruption
Mason, E. I.; Antiochos, Spiro K.; Vourlidas, Angelos
This Letter reports observations of an event that connects all major classes of solar eruptions: those that erupt fully into the heliosphere versus those that fail and are confined to the Sun, and those that eject new flux into the heliosphere, in the form of a flux rope, versus those that eject only new plasma in the form of a jet. The event orig…
Masses of White Dwarf Binary Companions to Type Ia Supernovae Measured from Runaway Velocities
Hermes, J. J.; Shen, Ken J.; Chandra, Vedant +1 more
The recently proposed "dynamically driven double-degenerate double-detonation" (D6) scenario posits that Type Ia supernovae (SNe) may occur during dynamically unstable mass transfer between two white dwarfs (WDs) in a binary. This scenario predicts that the donor WD may then survive the explosion and be released as a hypervelocity runaw…
A Homogeneous Comparison between the Chemical Composition of the Large Magellanic Cloud and the Sagittarius Dwarf Galaxy
Bellazzini, M.; Mucciarelli, A.; Origlia, L. +3 more
Similarities in the chemical composition of two of the closest Milky Way satellites, namely, the Large Magellanic Cloud (LMC) and the Sagittarius (Sgr) dwarf galaxy, have been proposed in the literature, suggesting similar chemical enrichment histories between the two galaxies. This proposition, however, rests on different abundance analyses, whic…
Observations of the Quiet Sun during the Deepest Solar Minimum of the Past Century with Chandrayaan-2 XSM: Sub-A-class Microflares outside Active Regions
Joshi, Bhuwan; Janardhan, P.; Bhardwaj, Anil +12 more
Solar flares, with energies ranging over several orders of magnitude, result from impulsive release of energy due to magnetic reconnection in the corona. Barring a handful, almost all microflares observed in X-rays are associated with the solar active regions. Here we present, for the first time, a comprehensive analysis of a large sample of quiet…
Matching Globular Cluster Models to Observations
Rui, Nicholas Z.; Rodriguez, Carl L.; Chatterjee, Sourav +4 more
As ancient, gravitationally bound stellar populations, globular clusters represent abundant, vibrant laboratories, characterized by high frequencies of dynamical interactions, coupled to complex stellar evolution. Using surface brightness and velocity dispersion profiles from the literature, we fit 59 Milky Way globular clusters to dynamical model…
Measurements of Photospheric and Chromospheric Magnetic Field Structures Associated with Chromospheric Heating over a Solar Plage Region
Kitai, Reizaburo; Kleint, Lucia; Schad, Thomas A. +6 more
In order to investigate the relation between magnetic structures and the signatures of heating in plage regions, we observed a plage region with the He I 1083.0 nm and Si I 1082.7 nm lines on 2018 October 3 using the integral field unit mode of the GREGOR Infrared Spectrograph (GRIS) installed at the GREGOR telescope. During the GRIS observation, …
New Hydrodynamic Solutions for Line-driven Winds of Hot Massive Stars Using the Lambert W-function
Hillier, D. J.; Najarro, F.; Gormaz-Matamala, A. C. +3 more
Hot massive stars present strong stellar winds that are driven by absorption, scattering, and reemission of photons by the ions of the atmosphere (line-driven winds). A better comprehension of this phenomenon, and a more accurate calculation of hydrodynamics and radiative acceleration, is Required to reduce the number of free parameters in spectra…
LoCuSS: The Splashback Radius of Massive Galaxy Clusters and Its Dependence on Cluster Merger History
Smith, Graham P.; Babul, Arif; Finoguenov, Alexis +4 more
We present the direct detection of the splashback feature using the sample of massive galaxy clusters from the Local Cluster Substructure Survey (LoCuSS). This feature is clearly detected (above 5σ) in the stacked luminosity density profile obtained using the K-band magnitudes of spectroscopically confirmed cluster members. We obtained the best-fi…