Search Publications
Theoretical studies of low and high frequency electrostatic solitary waves in the magnetopause associated with asymmetric magnetic reconnection
Bharuthram, R.; Rufai, O. R.; Maharaj, S. K.
In a comprehensive analysis of Cluster data, Graham et al. (2015) have reported the existence of slow and fast electrostatic solitary waves (ESWs) associated with asymmetric magnetic reconnection arising from the merger of the magnetic fields, and mixing, of the hot tenuous magnetospheric plasma and the cooler dense magnetosheath plasma. Their ana…
The Influence of Dynamic Solar Oblateness on Tracking Data Analysis from Past and Future Mercury Missions
van der Zwaard, Rens; Dirkx, Dominic
When the BepiColombo spacecraft arrives at Mercury in late 2025, it will be able to measure the orbit of the planet with unprecedented accuracy, allowing for more accurate measurements of the perihelion advance of the planet, as predicted by the Theory of General Relativity (GR). A similar effect is produced by the gravitational oblateness of the …
The 3D Galactocentric Velocities of Kepler Stars: Marginalizing Over Missing Radial Velocities
Angus, Ruth; Foreman-Mackey, Daniel; Bedell, Megan +3 more
Precise Gaia measurements of positions, parallaxes, and proper motions provide an opportunity to calculate 3D positions and 2D velocities (i.e., 5D phase-space) of Milky Way stars. Where available, spectroscopic radial velocity (RV) measurements provide full 6D phase-space information, however there are now and will remain many stars without RV me…
Emission Line Galaxies in the SHARDS Hubble Frontier Fields. II. Limits on Lyman-continuum Escape Fractions of Lensed Emission Line Galaxies at Redshifts 2 < z < 3.5
Pérez-González, Pablo G.; Koekemoer, Anton M.; Conselice, Christopher J. +10 more
We present an investigation of escape fractions of UV photons from a unique sample of lensed low-mass emission line-selected galaxies at z < 3.5 found in the SHARDS Hubble Frontier Fields medium-band survey. We have used this deep imaging survey to locate 42 relatively low-mass galaxies down to log (M */M ⊙) = 7 in the red…
Analysis of the Distance Scales by Cepheids from the Gaia EDR3 Catalogue Data
Bobylev, V. V.; Bajkova, A. T.
We study the kinematics of a sample of classical Cepheids younger than 120 Myr. For these stars, the estimates of distances taken from Skowron et al., which are based on the period-luminosity relation, and the line-of-sight velocities and the proper motions from the Gaia catalog are available. There are also distance estimates derived from the tri…
A transient ultraluminous X-ray source in NGC 55
Cusumano, G.; Wolter, A.; Pinto, C. +14 more
Ultraluminous X-ray sources (ULXs) are a class of accreting compact objects with X-ray luminosities above 1039 erg s-1 . The average number of ULXs per galaxy is still not well-constrained, especially given the uncertainty on the fraction of ULX transients. Here, we report the identification of a new transient ULX in the gala…
A New Statistical Distance Scale for Planetary Nebulae, Based on Gaia EDR3
Ali, A.; Mindil, A.; Alghamdi, S. A. +1 more
The present work aims to build a new statistical distance scale for planetary nebulae (PNe) based on a rigorous calibration sample. The distances of the calibration sample are derived from the trigonometric parallax method using the recent measurements of Gaia Early Data Release 3 (Gaia EDR3). The new distance scale is created by applying the well…
Dense Molecular Clouds in the Crab Supernova Remnant
Bentley, Rory O.; Fabian, A. C.; Combes, F. +7 more
Molecular emission was imaged with ALMA from numerous components near and within bright H2-emitting knots and absorbing dust globules in the Crab Nebula. These observations provide a critical test of how energetic photons and particles produced in a young supernova remnant interact with gas, cleanly differentiating between competing mod…
Dark Energy Camera photometry reveals extra-tidal stars around the Milky Way globular cluster NGC 6864 (M75)
Piatti, Andrés E.
Globular clusters are prone to lose stars while moving around the Milky Way. These stars escape the clusters and are distributed throughout extended envelopes or tidal tails. However, such extra-tidal structures are not observed in all globular clusters, and yet there are no structural or dynamical parameters that can predict their presence or abs…
The Detection of Deuterated Water in the Large Magellanic Cloud with ALMA
Oliveira, Joana M.; Chen, C. -H. Rosie; van Loon, Jacco Th. +10 more
We report the first detection of deuterated water (HDO) toward an extragalactic hot core. The HDO 211-212 line has been detected toward hot cores N 105-2 A and 2 B in the N 105 star-forming region in the low-metallicity Large Magellanic Cloud (LMC) dwarf galaxy with the Atacama Large Millimeter/submillimeter Array (ALMA). We …