Search Publications
On the 3D Transport of Low-energy Galactic Cosmic-ray and Jovian Electrons in the Inner Heliosphere in the Presence of a Fisk-type Heliospheric Magnetic Field
Engelbrecht, N. E.
Modeling the transport of low-energy (1‑10 MeV) cosmic-ray electrons can lead to valuable insights as to the behavior of the heliospheric magnetic field (HMF), due to the fact that the mean free path (MFP) of these particles parallel to the HMF is significantly larger than their perpendicular MFP, and that these particles experience little in the …
Casting Light on Degeneracies: A Comprehensive Study of Lightcurve Variations in Microlensing Events OGLE-2017-BLG-0103 and OGLE-2017-BLG-0192
Shah, Sarang
This study investigates orbital parallax in gravitational microlensing events, focusing on OGLE-2017-BLG-0103 and OGLE-2017-BLG-0192. For events with timescales ≤60 days, a Jerk-Parallax degeneracy arises due to high Jerk velocity (
Radio continuum emission from planetary nebulae in the Small Magellanic Cloud
Filipović, M. D.; Crawford, E. J.; Bojičić, I. +3 more
We report 11 new radio continuum measurements of established planetary nebulae (PNe) in the Small Magellanic Cloud (SMC) that we observed at 5.5 and 9 GHz with the Australia Telescope Compact Array (ATCA). These new radio detections are PNe with catalogued names: SMP SMC 2, SMP SMC 3, SMP SMC 5, SMP SMC 8, SMP SMC 13, SMP SMC 14, SMP SMC 19, MGPN …
Constraining ion transport in the diamagnetic cavity of comet 67P
Henri, P.; Rubin, M.; Galand, M. +3 more
The European Space Agency Rosetta mission escorted comet 67P for a 2-yr section of its six and a half-year orbit around the Sun. By perihelion in 2015 August, the neutral and plasma data obtained by the spacecraft instruments showed the comet had transitioned to a dynamic object with large-scale plasma structures and a rich ion environment. One su…
NNHMC: An Efficient Stokes Inversion Method Using a Neural Network (NN) Model Combined with the Hamiltonian Monte Carlo (HMC) Algorithm
Ji, KaiFan; Wang, JinLiang; Liu, Hui +6 more
The Milne–Eddington (M-E) atmosphere model is commonly adopted in the inversion of the magnetic fields in the solar photosphere. By applying the Levenberg–Marquardt algorithm or training a neural network (NN) model, the magnetic field vector can be quickly inferred from the Stokes profile but lacks reliable and statistically well-defined confidenc…
Unresolved Binary Systems with White Dwarfs in Open Star Clusters
Seleznev, A. F.; Mikhnevich, V. O.
We investigate unresolved binary systems with components of main sequence star (MS) and white dwarf (WD) in nine open clusters. These systems are located below and to the left of the main sequence on the color-magnitude diagram. We compare the number of cluster stars that have likely evolved into white dwarfs with the number of candidates for unre…
Abundance of strontium in the Galactic globular cluster 47 Tuc
Kučinskas, A.; Kolomiecas, E.; Dobrovolskas, V. +1 more
Aims: We have determined Sr abundance in a sample of 31 red giant branch stars located in the Galactic globular cluster 47 Tuc with the aim to identify potential differences in the Sr abundance between first population (1P, Na-poor) and second population (2P, Na-rich) stars.
Methods: We derived the Na and Sr abundances from the archival …
Solar differential rotation coefficients fitted from synoptic magnetic maps
Chu, Zhe; Gu, Haihua
Based on the consecutive synoptic magnetic maps, we devise a new method to calculate the solar differential rotation coefficients. This method is very easy to implement and has a high accuracy. Firstly, based on the two-term or three-term differential rotation formula, we simulate a synoptic map CR$_{n}$ evolves one Carrington Rotation (CR) time o…
Low CI/CO abundance ratio revealed by HST UV spectroscopy of CO-rich debris discs
Hughes, A. Meredith; Redfield, Seth; Roberge, Aki +6 more
The origin and evolution of CO gas in debris discs has been debated since its initial detection. The gas could have a primordial origin, as a remnant of the protoplanetary disc or a secondary exocometary origin. This paper investigates the origin of gas in two debris discs, HD110058 and HD131488, using Hubble Space Telescope (HST) observations of …
Using 26 Al to detect ongoing self-enrichment in young massive star clusters
Forbrich, Jan; Yates, Robert M.; Siegert, Thomas +5 more
Self-enrichment is one of the leading explanations for chemical anomalies in globular clusters. In this scenario, various candidate polluter stars have been proposed to eject gas with altered chemical composition during the self-enrichment process. Most of the proposed polluters will also eject radioactive