Search Publications
The high energy X-ray probe (HEX-P): studying extreme accretion with ultraluminous X-ray sources
Maitra, Chandreyee; Mori, Kaya; Wolter, Anna +25 more
Introduction: Ultraluminous X-ray sources (ULXs) represent an extreme class of accreting compact objects: from the identification of some of the accretors as neutron stars to the detection of powerful winds travelling at 0.1–0.2 c, the increasing evidence points towards ULXs harbouring stellar-mass compact objects undergoing highly super-Eddington…
A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15-1.73 GHz
Margot, Jean-Luc; Lynch, Ryan S.; Chen, James +77 more
We conducted a search for narrowband radio signals over four observing sessions in 2020-2023 with the L-band receiver (1.15-1.73 GHz) of the 100 m diameter Green Bank Telescope. We pointed the telescope in the directions of 62 TESS Objects of Interest, capturing radio emissions from a total of ~11,680 stars and planetary systems in the ~9' beam of…
A Young White Dwarf Orbiting PSR J1835-3259B in the Bulge Globular Cluster NGC 6652
Cadelano, Mario; Pallanca, Cristina; Ferraro, Francesco R. +8 more
We report on the discovery of the companion star to the millisecond pulsar PSR J1835-3259B in the Galactic globular cluster NGC 6652. Taking advantage of deep photometric archival observations acquired through the Hubble Space Telescope in near-UV and optical bands, we identified a bright and blue object at a position compatible with that of the r…
Modeling the Formation and Evolution of Solar Wind Microstreams: From Coronal Plumes to Propagating Alfvénic Velocity Spikes
Rouillard, Alexis P.; Réville, Victor; Gannouni, Bahaeddine
We investigate the origin of mesoscale structures in the solar wind called microstreams, defined as enhancements in the solar wind speed and temperature that last several hours. They were first clearly detected in Helios and Ulysses solar wind data and are now omnipresent in the "young" solar wind measured by the Parker Solar Probe and Solar Orbit…
Composite Bulges. III. A Study of Nuclear Star Clusters in Nearby Spiral Galaxies
Beckman, John E.; Bender, Ralf; Drory, Niv +17 more
We present photometric and morphological analyses of nuclear star clusters (NSCs)-very dense, massive star clusters present in the central regions of most galaxies-in a sample of 33 massive disk galaxies within 20 Mpc, part of the "Composite Bulges Survey." We use data from the Hubble Space Telescope including optical (F475W and F814W) and near-IR…
Cluster Observation on the Latitudinal Distribution of Magnetic Pc5 Pulsations in the Inner Magnetosphere
Cao, Jinbin; Li, Xinlin; Liu, Wenlong +4 more
Ultralow frequency (ULF) waves in the Pc5 band are ubiquitous in the inner magnetosphere and can impact radiation belt dynamics by interacting with electrons through drift or drift-bounce resonance. In this paper, based on ∼ 19 years of Cluster measurements, we perform a comprehensive study of the three-dimensional distribution of poloidal, toroid…
Searching for Gravitational-wave Counterparts Using the Transiting Exoplanet Survey Satellite
Jayaraman, Rahul; Ricker, George R.; Vanderspek, Roland +3 more
In 2017, the LIGO and Virgo gravitational-wave (GW) detectors, in conjunction with electromagnetic (EM) astronomers, observed the first GW multimessenger astrophysical event, the binary neutron star (BNS) merger GW170817. This marked the beginning of a new era in multimessenger astrophysics. To discover further GW multimessenger events, we explore…
Asteroids' reflectance from Gaia DR3: Artificial reddening at near-UV wavelengths
Tatsumi, E.; Tanga, P.; De Angeli, F. +6 more
Context. Observational and instrumental difficulties observing small bodies below 0.5 µm make this wavelength range poorly studied compared with the visible and near-infrared. Furthermore, the suitability of many commonly used solar analogues, essential in the computation of asteroid reflectances, is usually assessed only in visible waveleng…
Enhancing the alignment of the optically bright Gaia reference frame with respect to the International Celestial Reference System
Xu, Ming H.; Anderson, James M.; Lunz, Susanne +4 more
Context. The link of the Gaia frame in terms of non-rotation with respect to the International Celestial Reference System (ICRS), which is realized via very long baseline interferometry (VLBI) at radio wavelengths, has to be conducted for the wide range of optical magnitudes in which the spacecraft observes. There is a sufficient number of suitabl…
Identifying Symbiotic Stars with Machine Learning
Lü, Guoliang; Guo, Sufen; Jia, Yongle +3 more
Symbiotic stars are interacting binary systems, making them valuable for studying various astronomical phenomena, such as stellar evolution, mass transfer, and accretion processes. Despite recent progress in the discovery of symbiotic stars, a significant discrepancy between the observed population of symbiotic stars and the number predicted by th…