Search Publications
Turbulence in the Solar Atmosphere and Solar Wind
Balogh, A.; Marsch, E.; Goldstein, M. L. +6 more
The objective of this review article is to critically analyze turbulence and its role in the solar atmosphere and solar wind, as well as to provide a tutorial overview of topics worth clarification. Although turbulence is a ubiquitous phenomenon in the sun and its heliosphere, many open questions exist concerning the physical mechanisms of turbule…
Two Magnetar Candidates in HESS Supernova Remnants
Gotthelf, E. V.; Halpern, J. P.
We identify two candidate magnetars in archival X-ray observations of HESS-detected shell-type supernova remnants (SNRs). X-ray point sources in CTB 37B coincident with HESS J1713 - 381 and in G353.6 - 0.7 coincident with HESS J1731 - 347 both have anomalous X-ray pulsar (AXP) like spectra, much softer than those of ordinary, rotation-powered puls…
The Debris Disk of Vega: A Steady-state Collisional Cascade, Naturally
Krivov, A. V.; Löhne, T.; Müller, S.
The archetypical debris disk around Vega has been observed intensively over the past 25 years. It has been argued that the resulting photometric data and images may be in contradiction with a standard, steady-state collisional scenario of the disk evolution. In particular, the emission in the mid-infrared (mid-IR) appears to be in excess of what i…
Revealing Type Ia Supernova Physics with Cosmic Rates and Nuclear Gamma Rays
Beacom, John F.; Horiuchi, Shunsaku
Type Ia supernovae (SNe Ia) remain mysterious despite their central importance in cosmology and their rapidly increasing discovery rate. The progenitors of SNe Ia can be probed by the delay time between progenitor birth and explosion as SNe Ia. The explosions and progenitors of SNe Ia can be probed by MeV nuclear gamma rays emitted in the decays o…
The ACS LCID Project. II. Faint Variable Stars in the Isolated Dwarf Irregular Galaxy IC 1613
Skillman, Evan D.; Monelli, Matteo; Stetson, Peter B. +6 more
We present the results of a new search for variable stars in the Local Group (LG) isolated dwarf galaxy IC 1613, based on 24 orbits of F475W and F814W photometry from the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope. We detected 259 candidate variables in this field, of which only 13 (all of them bright Cepheids) were prev…
Chemical Composition of Icy Satellite Surfaces
Stephan, K.; Carlson, R. W.; McCord, T. B. +4 more
Much of our knowledge of planetary surface composition is derived from remote sensing over the ultraviolet through infrared wavelength ranges. Telescopic observations and, in the past few decades, spacecraft mission observations have led to the discovery of many surface materials, from rock-forming minerals to water ice to exotic volatiles and org…
Small Magnetic Loops Connecting the Quiet Surface and the Hot Outer Atmosphere of the Sun
Bellot Rubio, L. R.; Asensio Ramos, A.; Martínez González, M. J. +1 more
Sunspots are the most spectacular manifestation of solar magnetism, yet 99% of the solar surface remains "quiet" at any time of the solar cycle. The quiet sun is not void of magnetic fields, though; they are organized at smaller spatial scales and evolve relatively fast, which makes them difficult to detect. Thus, although extensive quiet Sun magn…
Fibrillar Chromospheric Spicule-like Counterparts to an Extreme-ultraviolet and Soft X-ray Blowout Coronal Jet
Harra, Louise K.; Moore, Ronald L.; Sterling, Alphonse C.
We observe an erupting jet feature in a solar polar coronal hole, using data from Hinode/Solar Optical Telescope (SOT), Extreme Ultraviolet Imaging Spectrometer (EIS), and X-Ray Telescope (XRT), with supplemental data from STEREO/EUVI. From extreme-ultraviolet (EUV) and soft X-ray (SXR) images we identify the erupting feature as a blowout coronal …
Aeolian processes and dune morphology in Gale Crater
Hobbs, Steven W.; Paull, David J.; Bourke, Mary C.
Datasets at resolutions many times greater than previously available were used to study aeolian features within Gale Crater. High resolution thermal inertia data allowed for detailed particle size estimation, with the data sufficient to resolve dunefields. A wide range of grain sizes have now been identified in the Gale Crater dunefields, ranging …
Suzaku Observation of GRS 1915+105: Evolution of Accretion Disk Structure during Limit-cycle Oscillation
Yamaoka, K.; Done, C.; Fukazawa, Y. +9 more
We present results from the Suzaku observation of the microquasar GRS 1915+105 performed during the 2005 October multiwavelength campaign. The data include both stable state (class χ) and limit-cycle oscillation (class θ). Correct interstellar absorption as well as effects of dust scattering are fully taken into account in the spectral analysis. T…