Search Publications
Particle acceleration in a nearby galaxy cluster pair: the role of cluster dynamics
Brunetti, G.; Rossetti, M.; Shimwell, T. W. +17 more
Context. Diffuse radio emission associated with the intracluster medium (ICM) is observed in a number of merging galaxy clusters. It is currently believed that a fraction of the kinetic energy in mergers is channeled into nonthermal components, such as turbulence, cosmic rays, and magnetic fields, which may lead to the formation of giant synchrotr…
Star-disc (mis-)alignment in Rho Oph and Upper Sco: insights from spatially resolved disc systems with K2 rotation periods
Davies, Claire L.
The discovery of close in, giant planets (hot Jupiters) with orbital angular momentum vectors misaligned with respect to the rotation axis of their host stars presents problems for planet formation theories in which planets form in discs with angular momentum vectors aligned with that of the star. Violent, high-eccentricity migration mechanisms pu…
An Ongoing Mid-infrared Outburst in the White Dwarf 0145+234: Catching in Action the Tidal Disruption of an Exoasteroid?
Ge, Jian; Wright, Edward L.; Bauer, James +7 more
We report the detection of a large-amplitude MIR outburst in the white dwarf (WD) 0145+234 in the NEOWISE Survey data. The source had a stable MIR flux before 2018, and was brightened by about 1.0 magnitude in the W1 and W2 bands within half a year and has been continuously brightening since then. No significant variations are found in the optical…
Nature of Faint Radio Sources in GOODS-North and GOODS-South Fields. I. Spectral Index and Radio-FIR Correlation
Giavalisco, Mauro; Yun, Min S.; Kawabe, Ryohei +9 more
We present the first results from the deep and wide 5 GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North (σ = 3.5 µJy beam-1, synthesized beam size θ = 1.″47 × 1.″42, and 52 sources over 109 arcmin2) and GOODS-South (σ = 3.0 µJy beam-1, θ = 0.″98 × 0.″45, and 88 sources …
Fast Solar Image Classification Using Deep Learning and Its Importance for Automation in Solar Physics
Fletcher, Lyndsay; Armstrong, John A.
The volume of data being collected in solar physics has exponentially increased over the past decade and with the introduction of the Daniel K. Inouye Solar Telescope (DKIST) we will be entering the age of petabyte solar data. Automated feature detection will be an invaluable tool for post-processing of solar images to create catalogues of data re…
High-energy monitoring of NGC 4593 II. Broad-band spectral analysis: testing the two-corona model
Bianchi, S.; Cappi, M.; Ponti, G. +9 more
It is widely believed that the primary X-ray emission of AGN is due to the Comptonization of optical-UV photons from a hot electron corona, while the origin of the `soft-excess' is still uncertain and matter of debate. A second Comptonization component, called warm corona, was therefore proposed to account for the soft-excess, and found in agreeme…
Unusual Plasma and Particle Signatures at Mars and STEREO-A Related to CME-CME Interaction
Dumbović, Mateja; Temmer, Manuela; Veronig, Astrid +15 more
On 2017 July 25 a multistep Forbush decrease (FD) with a remarkable total amplitude of more than 15% was observed by Mars Science Laboratory/Radiation Assessment Detector at Mars. We find that these particle signatures are related to very pronounced plasma and magnetic field signatures detected in situ by STEREO-A on 2017 July 24, with a higher-th…
HALO7D II: The Halo Velocity Ellipsoid and Velocity Anisotropy with Distant Main-sequence Stars
Anderson, Jay; van der Marel, Roeland P.; Wetzel, Andrew +7 more
The Halo Assembly in Lambda Cold Dark Matter: Observations in 7 Dimensions (HALO7D) data set consists of Keck II/DEIMOS spectroscopy and Hubble Space Telescope-measured proper motions of Milky Way halo main-sequence turnoff stars in the CANDELS fields. In this paper, the second in the HALO7D series, we present the proper motions for the HALO7D sam…
Binary Red Supergiants. II. Discovering and Characterizing B-type Companions
Massey, Philip; Levesque, Emily M.; Morrell, Nidia I. +1 more
The percentage of massive main-sequence OB stars in binary systems is thought to be as high as 100%. However, very few Galactic binary red supergiants (RSGs) have been identified, despite the fact that these stars are the evolved descendants of OB stars. As shown in our recent paper, binary RSGs will likely have B-type companions, as dictated by s…
Detections and constraints on white dwarf variability from time-series GALEX observations
Hermes, J. J.; Shappee, B. J.; Tucker, M. A. +1 more
We search for photometric variability in more than 23 000 known and candidate white dwarfs (WDs), the largest ultraviolet survey compiled for a single study of WDs. We use GPHOTON, a publicly available calibration/reduction pipeline, to generate time-series photometry of WDs observed by GALEX. By implementing a system of weighted metrics, we selec…