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 …
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…
COBIPULSE: A Systematic Search for Compact Binary Millisecond Pulsars
Miles-Páez, Paulo A.; Turchetta, Marco; Simpson, Jordan A. +5 more
We report here the results obtained from a systematic optical photometric survey aimed at finding new compact binary millisecond pulsars (also known as "spiders"): the COmpact BInary PULsar SEarch. We acquired multiband optical images over 1 yr around 33 unidentified Fermi Large Area Telescope sources, selected as pulsar candidates based on their …
Enhanced Oxygen Ion Outflow at Earth and Mars due to the Concurrent Impact of a Stream Interaction Region
Thampi, Smitha V.; Bhaskar, Ankush; Venkataraman, V. +1 more
One of the major processes that solar wind drives is the outflow and escape of ions from the planetary atmospheres. The major ion species in the upper ionospheres of both Earth and Mars is O+, and hence it is more likely to dominate the escape process. On Earth, due to a strong intrinsic magnetic field, the major ion outflow pathways ar…
Meridional Flow in the Solar Polar Caps Revealed by Magnetic Field Observation and Simulation
Hou, Yijun; Li, Ting; Yang, Shuhong +10 more
As a large-scale motion on the Sun, the meridional flow plays an important role in determining magnetic structure and strength and solar cycle. However, the meridional flow near the solar poles is still unclear. The Hinode observations show that the magnetic flux density in polar caps decreases from the lower latitudes to the poles. Using a surfac…
An Analysis of the Complex and Compact Outflow Cavity Carved by HOPS 361-A in NGC 2071 IR
Narang, Mayank; Coudé, Simon; Quillen, Alice C. +10 more
We present a combined Stratospheric Observatory for Infrared Astronomy (SOFIA) and two-epoch Hubble Space Telescope (HST) study of the region NGC 2071 IR containing the outflow from the protostar HOPS 361-A (NGC 2071 IRS 1). New [O I] 63 µm spectra, taken with the German REciever for Astronomy at Terahertz frequencies (GREAT) instrument aboa…
GBT/Argus Observations of Molecular Gas in the Inner Regions of IC 342
Bolatto, Alberto D.; Leroy, Adam K.; Rosolowsky, Erik +9 more
We report observations of the ground state transitions of 12CO, 13CO, C18O, HCN, and HCO+ at 88–115 GHz in the inner region of the nearby galaxy IC 342. These data were obtained with the 16 pixel spectroscopic focal plane array Argus on the 100 m Robert C. Byrd Green Bank Telescope (GBT) at 6″–9″ resolut…
X-Rays from the Nearby Compact Emission-line Galaxy NGC 2366
Kaaret, Philip; Prestwich, Andrea
Luminous, compact emission-line galaxies (LCGs) are the most abundant class of confirmed Lyman continuum (LyC) emitters. An optical integral field study of the nearby LCG NGC 2366 reveals an outflow originating at the star cluster "knot B" thought to clear a channel via mechanical feedback that enables LyC escape. We observed NGC 2366 with the Cha…
Revisiting Physical Parameters of the Benchmark Brown Dwarf LHS 6343 C through a Hubble Space Telescope/WFC3 Secondary-eclipse Observation
Montet, Benjamin T.; Gagné, Jonathan; Albert, Loïc +7 more
The LHS 6343 system consists of a resolved M-dwarf binary with an evolved, negligibly irradiated brown dwarf (BD), LHS 6343 C, orbiting the primary star. Such BD eclipsing binaries present rare and unique opportunities to calibrate substellar evolutionary and atmosphere models since mass, radius, temperature, and luminosity can be directly measure…
Evolving Outer Heliosphere: Tracking Solar Wind Transients from 1 au to the VLISM with IBEX and Voyager 1
Reisenfeld, D. B.; McComas, D. J.; Rankin, J. S. +5 more
Interstellar Boundary Explorer (IBEX) observations of energetic neutral atom (ENA) fluxes from the heliosphere have greatly enriched our understanding of the interaction of the solar wind (SW) with the local interstellar medium (LISM). However, there has been recent controversy surrounding the inability of most ENA models to produce as high an int…