Search Publications
Statistical Signatures of Nanoflare Activity. II. A Nanoflare Explanation for Periodic Brightenings in Flare Stars Observed by NGTS
Mathioudakis, M.; Wheatley, P. J.; Goad, M. R. +9 more
Several studies have documented periodic and quasi-periodic signals from the time series of dMe flare stars and other stellar sources. Such periodic signals, observed within quiescent phases (i.e., devoid of larger-scale microflare or flare activity), range in a period from 1 to 1000 s and hence have been tentatively linked to ubiquitous p-mode os…
Local Starburst Conditions and Formation of GRB 980425/SN 1998bw within a Collisional Ring
Pian, E.; Bournaud, F.; Cormier, D. +9 more
We present the first spatially resolved study of molecular gas in the vicinity of a gamma-ray burst (GRB), using CO(2-1) emission-line observations with the Atacama Large Millimetre Array at ∼50 pc scales. The host galaxy of GRB 980425 contains a ring of high column density H I gas, which is likely to have formed due to a collision between the GRB…
Characterizing the Evolved Stellar Population in the Galactic Foreground. I. Bolometric Magnitudes, Spatial Distribution and Period-Luminosity Relations
Brown, Anthony G. A.; Rich, R. Michael; Stroh, Michael C. +6 more
Radio campaigns using maser stellar beacons have provided crucial information to characterize Galactic stellar populations. Currently, the Bulge Asymmetries and Dynamical Evolution (BAaDE) project is surveying infrared (IR) color-selected targets for SiO masers. This provides a sample of evolved stars that can be used to study the inner, optically…
Observations of Outward-propagating and Mirroring of the Same Energetic Electrons by Wind
Zhao, L.; Li, G.; Yao, S. +1 more
We report an energetic electron event observed by the Wind spacecraft in which electrons were first detected to propagate away from the Sun, and subsequently detected to propagate back toward the Sun. Using the recently developed fractional velocity dispersion analysis (FVDA), the path lengths corresponding to these two sequential electron signals…
Comparison of Kinematics of Solar Eruptive Prominences and Spatial Distribution of the Magnetic Decay Index
Myshyakov, Ivan; Tsvetkov, Tsvetan
Theoretical studies of electric current instability explaining solar prominence eruptions show that the loss of equilibrium may develop in a case when the surrounding magnetic field decreases sufficiently rapidly with height. The magnetic decay index, a parameter indicating whether the external magnetic field has a configuration that may lead to a…
Testing ΛCDM with Dwarf Galaxy Morphology
Xu, Weishuang Linda; Randall, Lisa
The leading tensions to the collisionless cold dark matter (CDM) paradigm are the "small-scale controversies," discrepancies between observations at the dwarf-galactic scale, and their simulational counterparts. In this work we consider methods to infer 3D morphological information on Local Group dwarf spheroidals and test the fitness of CDM+hydro…
Relationship between Current Filaments and Turbulence During a Turbulent Reconnection
Yu, Y.; Chen, Z. Z.; Chen, F. +1 more
Both magnetic reconnection and turbulence can play crucial roles in space plasmas. The current layers, developing during magnetic reconnection, can collapse into various small-scale coherent structures, such as current filaments. These current filaments can significantly modulate the kinetic-scale turbulence. However, the quantitative correlation …
Spatially Resolved C III] λ1909 Emission in Haro 11
Hayes, Matthew; Inoue, Akio K.; Östlin, Göran +7 more
The C III] 1909 (hereafter C III]) line is the strongest ultraviolet emission line after Lyα and is therefore of interest to high-redshift studies of star-forming (SF) galaxies near the epoch of reionization. It is thought that C III] emission is strongest in galaxies with subsolar metallicity and low mass; however, spectral observations of numero…
Long-term Near-infrared Brightening of Nonvariable OH/IR Stars
Mito, Hiroyuki; Nakada, Yoshikazu; Ita, Yoshifusa +8 more
Nonvariable OH/IR stars are thought to have just left the asymptotic giant branch (AGB) phase. In this conventional picture, they must still show strong circumstellar extinction caused by the dust ejected during the AGB phase, and the extinction is expected to decrease over time because of the dispersal of the circumstellar dust after the cessatio…
Herschel 158 µm [{C} {II}}] Observations of "CO-dark" Gas in the Perseus Giant Molecular Cloud
Stanimirović, Snežana; Lee, Min-Young; Wolfire, Mark +2 more
We present observations of velocity-resolved [C II] 158 µm emission from both a dense and a more diffuse photodissociation region (PDR) in the Perseus giant molecular cloud using the Heterodyne Instrument for the Far-Infrared on board the Herschel Space Telescope. We detect [C II] emission from 80% of the total positions, with a 95% detectio…