Search Publications
Hubble Space Telescope Observations within the Sphere of Influence of the Powerful Supermassive Black Hole in PKS 0745-191
Steiner, James F.; Natarajan, Priyamvada; Edge, Alastair +18 more
We present Space Telescope Imaging Spectrograph observations from the Hubble Space Telescope of the supermassive black hole (SMBH) at the center of PKS 0745-191, a brightest cluster galaxy (BCG) undergoing powerful radio-mode active galactic nucleus (AGN) feedback (Pcav ~ 5 × 1045 erg s‑1). These high-resolution da…
Pulse-profile Modeling and Spin–Orbit Alignment in a Suzaku Sample of Accreting X-Ray Binary Pulsars
Paul, Biswajit; Laycock, Silas G. T.; Pradhan, Pragati +2 more
We report pulse-profile modeling of a sample of 23 X-ray binary pulsars observed with the Suzaku X-ray satellite. These pulsars have spin periods ranging from 0.7 to 9400 s, and their X-ray emission is powered by the accretion from their stellar companions. We fitted each individual pulse profile with the Polestar geometric model, which accounts f…
Magnetohydrodynamic Simulation of a Coronal Mass Ejection Observed during the Near-radial Alignment of Solar Orbiter and Earth
Pogorelov, Nikolai V.; Singh, Talwinder; Hegde, Dinesha V. +1 more
Interplanetary coronal mass ejections (ICMEs) are the primary sources of geomagnetic storms at Earth. The negative out-of-ecliptic component (Bz) of magnetic field in the ICME or its associated sheath region is necessary for it to be geoeffective. For this reason, magnetohydrodynamic simulations of CMEs containing data-constrained flux …
Discoveries and Properties of EL CVn–type Binaries in the TESS Survey
Han, Zhanwen; Chen, Xuefei; Li, Zhenwei +5 more
EL CVn–type systems represent a rare evolutionary stage in binary star evolution, providing ideal laboratories for investigating stable mass-transfer processes and the formation of extremely low-mass white dwarfs (ELM WDs). The Transiting Exoplanet Survey Satellite (TESS) has delivered an extensive collection of high-precision time-domain photomet…
ALMA Observations of Peculiar Embedded Icy Objects
Onaka, Takashi; Sakon, Itsuki; Shimonishi, Takashi
We report the results of molecular line observations with the Atacama Large Millimeter/submillimeter Array (ALMA) toward two peculiar icy objects, which were discovered serendipitously by infrared spectroscopic survey of the Galactic plane with the AKARI satellite. Previous infrared observations have reported that both objects show deep ice and du…
Hinode/EIS Observation of the Alfvénic Fluctuations in the Quiet Sun
Young, Peter R.; Morton, Richard; Tajfirouze, Edris
Alfvénic fluctuations in the corona are regularly observed in EUV imaging and infrared spectroscopic data. We report here on the Doppler velocity fluctuations within the data from the Extreme-Ultraviolet Imaging Spectrometer (EIS) on board Hinode. The capabilities of EIS provide an opportunity to detect fluctuations in the solar atmosphere and con…
An Improved Halo Coronal Mass Ejection Geoeffectiveness Prediction Model Using Multiple Coronal Mass Ejection Features Based on the DC-PCA-KNN Method
Ye, Dalin; Li, Huimin; Guo, Lixin +1 more
Coronal mass ejections (CME) are regarded as the main drivers of geomagnetic storms (GSs). In the prediction of geoeffectiveness, various CME features have been introduced without adequately considering the geoeffectiveness of CMEs and strong correlations among the features. In this study, a feature dimension reduction method combining distance co…
High-energy Jet Emission from GRS 1758–258 and 1E 1740.7–2942 with INTEGRAL?
Ubertini, Pietro; Bazzano, Angela; Rodi, James
GRS 1758–258 and 1E 1740.7–2942 are two long-known persistent black hole binaries in the Galactic center region. Using the International Gamma-Ray Astrophysics Laboratory (INTEGRAL)'s extensive monitoring of the Galactic center and bulge, we studied their temporal and spectral evolutions in the 30–610 keV energy range from 2003 March through 2022 …
PSR J1947‑1120: A New Huntsman Millisecond Pulsar Binary
Strader, Jay; Dage, Kristen C.; Deneva, Julia S. +11 more
We present the discovery of PSR J1947–1120, a new huntsman millisecond pulsar with a red giant companion star in a 10.3 day orbit. This pulsar was found via optical, X-ray, and radio follow-up of the previously unassociated γ-ray source 4FGL J1947.6–1121. PSR J1947–1120 is the second confirmed pulsar in the huntsman class and establishes this as a…
Alpha–Proton Relative Drift: Implications for the Origins and Dynamics of the Solar Wind
Matteini, Lorenzo; Wang, Joseph H.; Horbury, Timothy S. +1 more
Helium nuclei (alpha particles) strongly influence the momentum and energy balance in the solar wind, comprising up to 20% of the solar wind mass density. In fast Alfvénic wind at heliocentric distances greater than 0.3 au, the alpha particles' bulk flow speed is systematically different to that of the protons. This relative drift speed is of unkn…