Search Publications
Missions
Journals
Publication Years
Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona
Landi, E.; Testa, P.
In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017…
The evolution of the emission measure distribution in the core of an active region
Del Zanna, Giulio; Tripathi, Durgesh; Mason, Helen +2 more
We study the spatial distribution and evolution of the slope of the emission measure (EM) between 1 MK and 3 MK in the core of the active region (AR) NOAA 11193, first when it appeared near the central meridian and then again when it reappeared after a solar rotation. We use observations recorded by the Extreme-ultraviolet Imaging Spectrometer (EI…
Spatially resolved physical conditions of molecular gas and potential star formation tracers in M 83, revealed by the Herschel SPIRE FTS
Bournaud, F.; Lebouteiller, V.; Madden, S. C. +19 more
We investigate the physical properties of the molecular and ionized gas, and their relationship to the star formation and dust properties in M 83, based on submillimeter imaging spectroscopy from within the central 3.5' (~4 kpc in diameter) around the starburst nucleus. The observations use the Fourier Transform Spectrometer (FTS) of the Spectral …
Hubble Space Telescope Proper Motions along the Sagittarius Stream. I. Observations and Results for Stars in Four Fields
Anderson, Jay; Law, David R.; van der Marel, Roeland P. +5 more
We present a multi-epoch Hubble Space Telescope (HST) study of stellar proper motions (PMs) for four fields spanning 200° along the Sagittarius (Sgr) stream: one trailing arm field, one field near the Sgr dwarf spheroidal tidal radius, and two leading arm fields. We determine absolute PMs of dozens of individual stars per field, using established …
The Seyfert 2 galaxy NGC 2110: hard X-ray emission observed by NuSTAR and variability of the iron Kα line
Harrison, F.; Stern, D.; Bauer, F. E. +16 more
We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTA…
The Gemini NICI Planet-Finding Campaign: asymmetries in the HD 141569 disc
Kuchner, Marc J.; Wahhaj, Zahed; Biller, Beth A. +8 more
We report here the highest resolution near-IR imaging to date of the HD 141569A disc taken as part of the NICI (near infrared coronagraphic imager) Science Campaign. We recover four main features in the NICI images of the HD 141569 disc discovered in previous Hubble Space Telescope (HST) imaging: (1) an inner ring/spiral feature. Once deprojected,…
On Flare Predictability Based on Sunspot Group Evolution
Erdélyi, R.; Korsós, M. B.; Ludmány, A. +1 more
The forecast method introduced by Korsós et al. is generalized from the horizontal magnetic gradient (GM), defined between two opposite polarity spots, to all spots within an appropriately defined region close to the magnetic neutral line of an active region. This novel approach is not limited to searching for the largest GM …
Suzaku Observations of γ-Ray Bright Radio Galaxies: Origin of the X-Ray Emission and Broadband Modeling
Fukazawa, Yasushi; Itoh, Ryosuke; Stawarz, Łukasz +3 more
We performed a systematic X-ray study of eight nearby γ-ray bright radio galaxies with Suzaku in order to understand the origins of their X-ray emissions. The Suzaku spectra for five of those have been presented previously, while the remaining three (M87, PKS 0625-354, and 3C 78) are presented here for the first time. Based on the Fe-K line streng…
Measuring Infrared Surface Brightness Fluctuation Distances with HST WFC3: Calibration and Advice
Blakeslee, John P.; Jensen, Joseph B.; Cantiello, Michele +5 more
We present new calibrations of the near-infrared (near-IR) surface brightness fluctuation (SBF) distance method for the F110W ({J}110) and F160W ({H}160) bandpasses of the Wide Field Camera 3 Infrared Channel (WFC3/IR) on the Hubble Space Telescope. The calibrations are based on data for 16 early-type galaxies in the Virgo an…
Explosive volcanic activity on Venus: The roles of volatile contribution, degassing, and external environment
Wilson, C. F.; Glaze, L. S.; Airey, M. W. +3 more
We investigate the conditions that will promote explosive volcanic activity on Venus. Conduit processes were simulated using a steady-state, isothermal, homogeneous flow model in tandem with a degassing model. The response of exit pressure, exit velocity, and degree of volatile exsolution was explored over a range of volatile concentrations (H