Search Publications
An Unorthodox X-Class Long-duration Confined Flare
Wang, Haimin; Wang, Yuming; Liu, Rui +3 more
We report the observation of an X-class long-duration flare which is clearly confined. It appears as a compact-loop flare in the traditional EUV passbands (171 and 195 Å), but in the passbands sensitive to flare plasmas (94 and 131 Å), it exhibits a cusp-shaped structure above an arcade of loops like other long-duration events. Inspecting images i…
The SCUBA-2 Cosmology Legacy Survey: Ultraluminous Star-forming Galaxies in a z = 1.6 Cluster
Thomson, A. P.; Ivison, R. J.; Scott, D. +23 more
We analyze new SCUBA-2 submillimeter and archival SPIRE far-infrared imaging of a z = 1.62 cluster, Cl 0218.3-0510, which lies in the UKIRT Infrared Deep Sky Survey/Ultra-Deep Survey field of the SCUBA-2 Cosmology Legacy Survey. Combining these tracers of obscured star-formation activity with the extensive photometric and spectroscopic information…
The Puzzling Chemical Composition of GJ 436b's Atmosphere: Influence of Tidal Heating on the Chemistry
Agúndez, Marcelino; Venot, Olivia; Iro, Nicolas +1 more
The dissipation of the tidal energy deposited on eccentric planets may induce a heating of the planet that affects its atmospheric thermal structure. Here we study the influence of tidal heating on the atmospheric composition of the eccentric (e = 0.16) "hot Neptune" GJ 436b, for which inconclusive chemical abundances are retrieved from multiwavel…
Solar Magnetized Tornadoes: Rotational Motion in a Tornado-like Prominence
Gan, Weiqun; Temmer, Manuela; Veronig, Astrid +5 more
Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However…
Evidence for Active Galactic Nucleus Feedback in the Broad Absorption Lines and Reddening of Mrk 231
Gallagher, Sarah C.; Terndrup, Donald M.; Leighly, Karen M. +3 more
We present the first J-band spectrum of Mrk 231, which reveals a large He I* λ10830 broad absorption line with a profile similar to that of the well-known Na I broad absorption line. Combining this spectrum with optical and UV spectra from the literature, we show that the unusual reddening noted by Veilleux et al. is explained by a reddening curve…
Thermal Structure of Current Sheets and Supra-arcade Downflows in the Solar Corona
Reeves, Katharine K.; Hanneman, Will J.
After the peak intensity of many large solar flares, magnetic and thermodynamic processes give rise to a phenomenon known as supra-arcade downflows (SADs). SADs are sunward flowing density depletions, often observed in post-flare plasma sheets. Some models have suggested that the plasma in the dark lanes is heated to temperatures of 20-80 MK, whic…
Transit Confirmation and Improved Stellar and Planet Parameters for the Super-Earth HD 97658 b and its Host Star
Queloz, D.; Demory, B. -O.; Ehrenreich, D. +15 more
Super-Earths transiting nearby bright stars are key objects that simultaneously allow for accurate measurements of both their mass and radius, providing essential constraints on their internal composition. We present here the confirmation, based on Spitzer transit observations, that the super-Earth HD 97658 b transits its host star. HD 97658 is a …
Physical Properties of White-light Sources in the 2011 February 15 Solar Flare
Fletcher, L.; Kerr, G. S.
White-light flares (WLFs) are observational rarities, making them understudied events. However, optical emission is a significant contribution to flare energy budgets and the emission mechanisms responsible could have important implications for flare models. Using Hinode SOT optical continuum data taken in broadband red, green, and blue filters, w…
Active Galactic Nucleus X-Ray Variability in the XMM-COSMOS Survey
Salvato, M.; Merloni, A.; Ponti, G. +18 more
We used the observations carried out by XMM in the COSMOS field over 3.5 yr to study the long term variability of a large sample of active galactic nuclei (AGNs) (638 sources) in a wide range of redshifts (0.1 < z < 3.5) and X-ray luminosities (1041 < L 0.5-10 <1045.5). Both a simple statistical method …
Mechanisms and Observations of Coronal Dimming for the 2010 August 7 Event
Thompson, B. J.; Mason, James Paul; Woods, T. N. +2 more
Coronal dimming of extreme ultraviolet (EUV) emission has the potential to be a useful forecaster of coronal mass ejections (CMEs). As emitting material leaves the corona, a temporary void is left behind which can be observed in spectral images and irradiance measurements. The velocity and mass of the CMEs should impact the character of those obse…