Search Publications
Simulation of the Solar Energetic Particle Event on 2020 May 29 Observed by Parker Solar Probe
Balmaceda, Laura A.; Zhang, Ming; Lario, David +3 more
This paper presents a stochastic three-dimensional focused transport simulation of solar energetic particles (SEPs) produced by a data-driven coronal mass ejection (CME) shock propagating through a data-driven model of coronal and heliospheric magnetic fields. The injection of SEPs at the CME shock is treated using diffusive shock acceleration of …
The Equilibrium of Coronal Loops Near Separatrices
Antiochos, Spiro K.; Bradshaw, Stephen; Mason, Emily I.
We present numerical models from the field-aligned HYDrodynamics and RADiation code (HYDRAD) of a highly asymmetric closed coronal loop with near-singular expansion factor. This loop was chosen to simulate a coronal magnetic flux tube that passes close to a null point, as in the last set of closed loops under the fan surface of a coronal jet or a …
Raman Scattering by Atomic Hydrogen in Photodissociation Regions: An Alternative to the Polycyclic Aromatic Hydrocarbons Hypothesis
Zagury, Frédéric
Photodissociation regions (PDRs) illuminated by high temperature (T > 104 K) radiation fields display characteristic optical to midinfrared spectral features: emission bands that cluster around the blue limits of hydrogen series, an extended red emission (ERE) in the vicinity of Hα, and a continuum in the infrared part of the spectru…
Multifrequency Microwave Imaging of Weak Transients from the Quiet Solar Corona
Chen, Bin; Yu, Sijie; Mondal, Surajit
Understanding the dynamics of the quiet solar corona is important for answering key questions including the coronal heating problem. Multiple studies have suggested small-scale magnetic-reconnection events may play a crucial role. These reconnection events are expected to involve acceleration of electrons to suprathermal energies, which can then p…
Cannonball or Bowling Ball: Proper Motion and Parallax for PSR J0002+6216
Frail, D. A.; Kerr, M.; Schinzel, F. K. +4 more
We report the results of careful astrometric measurements of the cannonball pulsar J0002+6216 carried out over 3 yr using the High Sensitivity Array. We significantly refine the proper motion to µ = 35.3 ± 0.6 mas yr-1 and place new constraints on the distance, with the overall effect of lowering the velocity and increasing the in…
On the Short-period Eclipsing High-mass X-Ray Binary in NGC 4214
Soria, Roberto; Swartz, Douglas A.; Lin, Zikun
We present the results of our study of the luminous (L X ≈ 1039 erg s-1) X-ray binary CXOU J121538.2+361921 in NGC 4214, the high-mass X-ray binary with the shortest known orbital period. Using Chandra data, we confirm the ≈13,000 s (3.6 hr) eclipse period, and an eclipse duration of ≈2000 s. From this, we estimate…
Spicules in IRIS Mg II Observations: Automated Identification
Polito, Vanessa; Chamberlin, Phillip C.; Milligan, Ryan O. +4 more
We have developed an algorithm to identify solar spicules in the first ever systematic survey of on-disk spicules exclusively using Mg II spectral observations. Using this algorithm we identify 2021 events in three Interface Region Imaging Spectrograph (IRIS) data sets with unique solar feature targets spanning a total of 300 minutes: (1) active r…
Updated High-temperature Opacities for the Dartmouth Stellar Evolution Program and Their Effect on the Jao Gap Location
Boudreaux, Emily M.; Chaboyer, Brian C.
The Jao Gap, a 17% decrease in stellar density at M G ~ 10 identified in both Gaia Data Release 2 and Early Data Release 3, presents a new method to probe the interior structure of stars near the fully convective transition mass. The Gap is believed to originate from convective-kissing instability wherein asymmetric production of
The Interstellar Medium Scaling Relations Using Inner H I and an Application of Estimating Dust Mass
Lin, Zesen; Kong, Xu; Li, Fujia +4 more
We select a disk-like galaxy sample with observations of the H I, H2, and dust from the Herschel Reference Survey, and derive inner H I masses within the optical radius. We find that the inner gas-to-dust ratio is almost independent of gas-phase metallicity, and confirm that the inner gas mass (H I+H2) shows a tighter relatio…
Searching for C II Emission from the First Sample of z ∼ 6 O I Absorption-associated Galaxies with the Atacama Large Millimeter/submillimeter Array
Hennawi, Joseph F.; Fan, Xiaohui; Prochaska, J. Xavier +13 more
We report the first statistical analyses of [C II] and dust continuum observations in six strong O I absorber fields at the end of the reionization epoch obtained by the Atacama Large Millimeter/submillimeter Array (ALMA). Combined with one [C II] emitter reported in Wu et al., we detect one O I-associated [C II] emitter in six fields. At redshift…