Search Publications
Prediction of Astrometric and Timing Microlensing Events with Pulsars by ATNF Catalog and Gaia DR3
Xie, Yi; Lu, Xu
Determining the mass of neutron stars is crucial for understanding their formation, evolution, and interior structure. Currently, only a few dozen neutron stars have had their masses measured, and most of them belong to binary systems. However, there are a huge number of isolated neutron stars with unknown masses. Microlensing events with neutron …
Solar Energetic Particle and the Heliospheric Current Sheet
Wu, Chin-Chun; Liou, Kan
The effect of the heliospheric current sheet (HCS) on the propagation of solar energetic particles (SEPs) remains poorly known. In this study we address this question by surveying energetic (∼2.0–9.6 MeV nucleon–1) helium data acquired by the energetic particle acceleration, composition, and transport (EPACT) sensor on board the Wind sp…
A Panchromatic Study of the X-Ray Binary Population in NGC 300 on Subgalactic Scales
Williams, Benjamin F.; Eracleous, Michael; Binder, Breanna A. +3 more
The population-wide properties and demographics of extragalactic X-ray binaries (XRBs) correlate with the star formation rates (SFRs), stellar masses (M ⋆), and environmental factors (such as metallicity, Z) of their host galaxy. Although there is evidence that XRB scaling relations (L X/SFR for high-mass XRBs (HMXBs) and L <…
First Resolution of Microlensed Images of a Binary-lens Event
Tan, Thiam-Guan; Thompson, I. B.; Le Bouquin, Jean-Baptiste +72 more
We resolve the multiple images of the binary-lens microlensing event ASASSN-22av using the GRAVITY instrument of the Very Large Telescope Interferometer (VLTI). The light curves show weak binary-lens perturbations, complicating the analysis, but the joint modeling with the VLTI data breaks several degeneracies, arriving at a strongly favored solut…
The Radial Interplanetary Field Strength at Sunspot Minimum as Polar Field Proxy and Solar Cycle Predictor
Wang, Y. -M.
The minimum value of the geomagnetic aa index has served as a remarkably successful predictor of solar cycle amplitude. This value is reached near or just after sunspot minimum, when both the near-Earth solar wind speed and interplanetary magnetic field (IMF) strength fall to their lowest values. At this time, the heliospheric current sheet is fla…
Pulsation in TESS Objects of Interest
Janot-Pacheco, E.; Ferreira Lopes, C. E.; De Medeiros, J. R. +11 more
We report the discovery of three Transiting Exoplanet Survey Satellite Objects of Interest (TOI) with signatures of pulsation, observed in more than one sector. Our main goal is to explore how large is the variety of classical pulsators such as δ Sct, γ Dor, RR Lyrae and Cepheid among TOI pulsators. The analysis reveals two stars with signatures o…
Variable Stars in M31 Stellar Clusters from the Panchromatic Hubble Andromeda Treasury
Williams, Benjamin F.; Johnson, L. Clifton; Girardi, Léo +9 more
Variable stars in stellar clusters can offer key constraints on stellar evolution and pulsation models, utilizing estimates of host cluster properties to constrain stellar physical parameters. We present a catalog of 86 luminous (F814W < 19) variable stars in M31 clusters identified by mining the archival Panchromatic Hubble Andromeda Treasury …
A Joint Microwave and Hard X-Ray Study toward Understanding the Transport of Accelerated Electrons During an Eruptive Solar Flare
Chen, Bin; Yu, Sijie; Battaglia, Andrea F. +1 more
The standard flare model, despite its success, is limited in comprehensively explaining the various processes involving nonthermal particles. One such missing ingredient is a detailed understanding of the various processes involved during the transport of accelerated electrons from their site of acceleration to different parts of the flare region.…
A Surprising Excess of Radio Emission in Extremely Stable Quasars: A Unique Clue to Jet Launching?
Cai, Zhen-Yi; Wang, Jun-Xian; Yuan, Feng +6 more
Quasars are generally divided into jetted radio-loud and nonjetted radio-quiet ones, but why only 10% of quasars are radio-loud has been puzzling for decades. Other than jet-induced phenomena, black hole mass, or Eddington ratio, a prominent difference between jetted and nonjetted quasars has scarcely been detected. Here we show a unique distincti…
An Extremely Low-density Exoplanet Spins Slow
Zhu, Wei; Cañas, Caleb I.; Bello-Arufe, Aaron +3 more
We present constraints on the shape of Kepler-51d, which is a superpuff with a mass ∼6 M ⊕ and a radius ∼9 R ⊕, based on detailed modeling of the transit light curve from James Webb Space Telescope (JWST) NIRSpec. The projected shape of this extremely low-density planet is consistent with being spherical, and a projected obla…