Search Publications
Sympathetic Filament Eruptions within a Fan-spine Magnetic System
Shen, Yuandeng; Zhou, Chengrui; Zhou, Xinping +3 more
It is unclear whether successive filament eruptions at different sites within a short time interval are physically connected or not. Here, we present the observations of successive eruptions of a small and a large filament in a tripolar magnetic field region whose coronal magnetic field showed as a fan-spine magnetic system. By analyzing the multi…
On the initial mass-radius relation of stellar clusters
Kruijssen, J. M. Diederik; Choksi, Nick
Young stellar clusters across nearly five orders of magnitude in mass appear to follow a power-law mass-radius relationship (MRR), $R_{\star }\propto M_{\star }^{\alpha }$, with α ≈ 0.2-0.33. We develop a simple analytic model for the cluster mass-radius relation. We consider a galaxy disc in hydrostatic equilibrium, which hosts a population of mo…
Relative Ages of Nine Inner Milky Way Globular Clusters from Proper-motion-cleaned Color-Magnitude Diagrams
Brown, Thomas M.; Cohen, Roger E.; Casagrande, Luca +3 more
Our picture of the age-metallicity relation for Milky Way globular clusters (MWGCs) is still highly incomplete, and the majority of MWGCs lack self-consistent age measurements. Here, we exploit deep, homogenous multiepoch Hubble Space Telescope imaging of nine MWGCs located toward the inner Milky Way to measure their relative ages, in most cases f…
Rossby numbers and stiffness values inferred from gravity-mode asteroseismology of rotating F- and B-type dwarfs. Consequences for mixing, transport, magnetism, and convective penetration
Aerts, C.; Mathis, S.; Van Reeth, T. +5 more
Context. Multi-dimensional (magneto-)hydrodynamical simulations of physical processes in stellar interiors depend on a multitude of uncalibrated free parameters, which set the spatial and time scales of their computations.
Aims: We aim to provide an asteroseismic calibration of the wave and convective Rossby numbers, and of the stiffness at t…
Far-Infrared Line Diagnostics: Improving N/O Abundance Estimates for Dusty Galaxies
Lamarche, C.; Stacey, G. J.; Higdon, J. +8 more
The nitrogen-to-oxygen (N/O) abundance ratio is an important diagnostic of galaxy evolution because the ratio is closely tied to the growth of metallicity and the star formation history in galaxies. Estimates for the N/O are traditionally made with optical lines that could suffer from extinction and excitation effects, so the N/O is arguably measu…
An enhanced slope in the transmission spectrum of the hot Jupiter WASP-104b
Tamura, M.; Pallé, E.; Béjar, V. J. S. +25 more
We present the optical transmission spectrum of the hot Jupiter WASP-104b based on one transit observed by the blue and red channels of the Double Spectrograph (DBSP) at the Palomar 200-inch telescope and 14 transits observed by the MuSCAT2 four-channel imager at the 1.52-m Telescopio Carlos Sánchez. We also analyse 45 additional K2 transits, afte…
On the Effect of Magnetospheric Shielding on the Lunar Hydrogen Cycle
Farrell, W. M.; Tucker, O. J.; Poppe, A. R.
The global distribution of surficial hydroxyl on the Moon is hypothesized to be derived from the implantation of solar wind protons. As the Moon traverses the geomagnetic tail, it is generally shielded from the solar wind; therefore, the concentration of hydrogen is expected to decrease during full Moon. A Monte Carlo approach is used to model the…
Diagnosing the interstellar medium of galaxies with far-infrared emission lines. I. The [C II] 158 µm line at z ∼ 0
Wang, L.; van der Tak, F. F. S.; Trager, S. C. +2 more
Context. Atomic fine structure lines have been detected in the local Universe and at high redshifts over the past decades. The [C II] emission line at 158 µm is an important observable as it provides constraints on the interstellar medium (ISM) cooling processes.
Aims: We develop a physically motivated framework to simulate the producti…
The active region source of a type III radio storm observed by Parker Solar Probe during encounter 2
Barczynski, K.; Mandrini, C. H.; Bale, S. D. +6 more
Context. We investigated the source of a type III radio burst storm during encounter 2 of NASA's Parker Solar Probe (PSP) mission.
Aims: It was observed that in encounter 2 of NASA's PSP mission there was a large amount of radio activity and, in particular, a noise storm of frequent, small type III bursts from 31 March to 6 April 2019. Our ai…
Physical Parameters of the Multiplanet Systems HD 106315 and GJ 9827
Gorjian, Varoujan; Mayo, Andrew W.; Rice, Malena +42 more
HD 106315 and GJ 9827 are two bright, nearby stars that host multiple super-Earths and sub-Neptunes discovered by K2 that are well suited for atmospheric characterization. We refined the planets' ephemerides through Spitzer transits, enabling accurate transit prediction required for future atmospheric characterization through transmission spectros…