Search Publications
Understanding Coronal Mass Ejections and Associated Shocks in the Solar Corona by Merging Multiwavelength Observations
Pick, M.; Kerdraon, A.; Démoulin, P. +3 more
Using multiwavelength imaging observations, in EUV, white light and radio, and radio spectral data over a large frequency range, we analyzed the triggering and development of a complex eruptive event. This one includes two components, an eruptive jet and a coronal mass ejection (CME), which interact during more than 30 minutes, and can be consider…
Dust Formation, Evolution, and Obscuration Effects in the Very High-redshift Universe
Staguhn, Johannes; Arendt, Richard G.; Dwek, Eli +3 more
The evolution of dust at redshifts z >~ 9, and consequently the dust properties, differs greatly from that in the local universe. In contrast to the local universe, core collapse supernovae (CCSNe) are the only source of thermally condensed dust. Because of the low initial dust-to-gas mass ratio, grain destruction rates are low, so that CCSNe a…
Oscillations in a Sunspot with Light Bridges
Li, Bo; Huang, Zhenghua; Su, Jiangtao +4 more
The Solar Optical Telescope on board Hinode observed a sunspot (AR 11836) with two light bridges (LBs) on 2013 August 31. We analyzed a two-hour Ca II H emission intensity data set and detected strong five-minute oscillation power on both LBs and in the inner penumbra. The time-distance plot reveals that the five-minute oscillation phase does not …
The Lyman Alpha Reference Sample. III. Properties of the Neutral ISM from GBT and VLA Observations
Verhamme, Anne; Cannon, John M.; Hayes, Matthew +16 more
We present new H I imaging and spectroscopy of the 14 UV-selected star-forming galaxies in the Lyman Alpha Reference Sample (LARS), aimed for a detailed study of the processes governing the production, propagation, and escape of Lyα photons. New H I spectroscopy, obtained with the 100 m Green Bank Telescope (GBT), robustly detects the H I spectral…
A Data-driven Approach for Retrieving Temperatures and Abundances in Brown Dwarf Atmospheres
Fortney, Jonathan J.; Line, Michael R.; Marley, Mark S. +1 more
Brown dwarf spectra contain a wealth of information about their molecular abundances, temperature structure, and gravity. We present a new data driven retrieval approach, previously used in planetary atmosphere studies, to extract the molecular abundances and temperature structure from brown dwarf spectra. The approach makes few a priori physical …
Constraining the Atmospheric Composition of the Day-Night Terminators of HD 189733b: Atmospheric Retrieval with Aerosols
Fletcher, Leigh N.; Irwin, Patrick G. J.; Barstow, Joanna K. +2 more
A number of observations have shown that Rayleigh scattering by aerosols dominates the transmission spectrum of HD 189733b at wavelengths shortward of 1 µm. In this study, we retrieve a range of aerosol distributions consistent with transmission spectroscopy between 0.3-24 µm that were recently re-analyzed by Pont et al. To constrain t…
The Structure of the Local Interstellar Medium. VI. New Mg II, Fe II, and Mn II Observations toward Stars within 100 pc
Ayres, Thomas R.; Redfield, Seth; Wood, Brian E. +2 more
We analyze high-resolution spectra obtained with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope toward 34 nearby stars (<=100 pc) to record Mg II, Fe II, and Mn II absorption due to the local interstellar medium (LISM). Observations span the entire sky, probing previously unobserved regions of the LISM. The heavy io…
Distance Determinations to SHIELD Galaxies from Hubble Space Telescope Imaging
McQuinn, Kristen B. W.; Cannon, John M.; Dolphin, Andrew E. +9 more
The Survey of H I in Extremely Low-mass Dwarf (SHIELD) galaxies is an ongoing multi-wavelength program to characterize the gas, star formation, and evolution in gas-rich, very low-mass galaxies. The galaxies were selected from the first ~10% of the H I Arecibo Legacy Fast ALFA (ALFALFA) survey based on their inferred low H I mass and low baryonic …
Discovery of the Hard Spectrum VHE γ-Ray Source HESS J1641-463
Klochkov, D.; Santangelo, A.; Quirrenbach, A. +229 more
This Letter reports the discovery of a remarkably hard spectrum source, HESS J1641-463, by the High Energy Stereoscopic System (H.E.S.S.) in the very high energy (VHE) domain. HESS J1641-463 remained unnoticed by the usual analysis techniques due to confusion with the bright nearby source HESS J1640-465. It emerged at a significance level of 8.5 s…
Unusual Water Production Activity of Comet C/2012 S1 (ISON): Outbursts and Continuous Fragmentation
Bertaux, J. -L.; Combi, M. R.; Fougere, N. +3 more
The Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyα camera on the SOlar and Heliospheric Observer (SOHO) satellite observed the hydrogen coma of comet C/2012 S1 (ISON) for most of the last month of its activity from 2013 October 24 to November 24, ending just 4 days before perihelion and its final disruption. The water production rate of the c…