Search Publications
Variability of Blue Supergiants in the LMC with TESS
de Mink, Selma E.; Johnston, Cole; Ma, Linhao +1 more
The blue supergiant (BSG) problem, namely, the overabundance of BSGs inconsistent with classical stellar evolution theory, remains an open question in stellar astrophysics. Several theoretical explanations have been proposed, which may be tested by their predictions for the characteristic time variability. In this work, we analyze the light curves…
LOFAR detection of extended emission around a mini halo in the galaxy cluster Abell 1413
Rossetti, M.; Shimwell, T. W.; Gastaldello, F. +14 more
Context. The relation between giant radio halos and mini halos in galaxy clusters is not understood. The former are usually associated with merging clusters, while the latter are found in relaxed systems. In recent years, the advent of low-frequency radio observations has challenged this dichotomy by finding intermediate objects with a hybrid radi…
Solar Wind Current Sheets: MVA Inaccuracy and Recommended Single-Spacecraft Methodology
Wang, R.; Phan, T. D.; Mozer, F. S. +1 more
We present the analysis of 1,831 current sheets (CS) observed aboard four Cluster spacecraft in a pristine solar wind. Four-spacecraft estimates of the CS normal and propagation velocity are compared with different single-spacecraft estimates. The Minimum Variance Analysis (MVA) of the magnetic field is shown to be highly inaccurate in estimating …
JWST Confirms the Nature of CID-42
Shen, Yue; Zhuang, Ming-Yang; Li, Junyao
The galaxy CID-42 (CXOC J100043.1+020637.2) at z = 0.359 has been proposed to contain a promising candidate for a gravitational-wave recoiling supermassive black hole (SMBH), a slingshot SMBH from a triple-SMBH interaction, or a kiloparsec-scale dual active galactic nucleus (AGN). These claims were primarily based on a pair of bright cores separat…
No evidence of active galactic nucleus features in the nuclei of Arp 220 from JWST/NIRSpec IFS
Charlot, Stéphane; Übler, Hannah; D'Eugenio, Francesco +12 more
Context. Arp 220 is the nearest ultra-luminous infrared galaxy. It shows evidence of 100 pc scale molecular outflows that are likely connected with galaxy-scale outflows traced by ionised and neutral gas. The two highly obscured nuclei of Arp 220 are sites of intense star formation, with extreme (far-infrared based) star formation rate surface den…
Radial evolution of the accuracy of ballistic solar wind backmapping
Maksimovic, M.; Démoulin, P.; Badman, S. T. +4 more
Context. Solar wind backmapping is a technique employed to connect in situ measurements of heliospheric plasma structures to their origin near the Sun. The most widely used method is ballistic mapping, which neglects the effects of solar wind acceleration and corotation and instead models the solar wind as a constant radial outflow whose speed is …
The evolution of catastrophically evaporating rocky planets
Owen, James E.; Curry, Alfred; Booth, Richard +1 more
In this work, we develop a rocky planet interior model and use it to investigate the evolution of catastrophically evaporating rocky exoplanets. These planets, detected through the dust tails produced by evaporative outflows from their molten surfaces, can be entirely destroyed in a fraction of their host star's lifetime. To allow for the major de…
Evidence for morning-to-evening limb asymmetry on the cool low-density exoplanet WASP-107 b
Fortney, Jonathan J.; Bell, Taylor J.; Line, Michael R. +8 more
The atmospheric properties of hot exoplanets are expected to be different between the morning and the evening limbs due to their global atmospheric circulation. Ground-based observations at high spectral resolution have detected this limb asymmetry in several ultra-hot (>2,000 K) exoplanets, but the prevalence of the phenomenon in the broader e…
New Measurements of the Lyα Forest Continuum and Effective Optical Depth with LyCAN and DESI Y1 Data
Juneau, S.; Moustakas, J.; Brooks, D. +42 more
We present the Lyα Continuum Analysis Network (LyCAN), a convolutional neural network that predicts the unabsorbed quasar continuum within the rest-frame wavelength range of 1040–1600 Å based on the red side of the Lyα emission line (1216–1600 Å). We developed synthetic spectra based on a Gaussian mixture model representation of nonnegative matrix…
Thermonuclear explosions on neutron stars reveal the speed of their jets
Kuulkers, Erik; Degenaar, Nathalie; Sánchez-Fernández, Celia +6 more
Relativistic jets are observed from accreting and cataclysmic transients throughout the Universe, and have a profound impact on their surroundings1,2. Despite their importance, their launch mechanism is not known. For accreting neutron stars, the speed of their compact jets can reveal whether the jets are powered by magnetic fields anch…