Search Publications
Advection and dispersal of small magnetic elements in the very quiet Sun
Asensio Ramos, A.; Martínez González, M. J.; Manso Sainz, R.
We track small magnetic structures on very quiet regions (internetwork) of the Sun. We follow the footpoints of small-scale magnetic loops that appear on the photosphere at granular scales using spectropolarimetric and magnetographic data obtained with Hinode. We find two different regimes for their wanderings. Within granules (where they appear),…
The nature of lunar volatiles as revealed by Mini-RF observations of the LCROSS impact site
Patterson, G. W.; Neish, C. D.; Bussey, D. B. J. +4 more
On 9 October 2009 the Lunar Crater Observation and Sensing Satellite (LCROSS) impacted Cabeus crater, located near the south pole of the Moon. Prior to that impact, the Mini-RF instruments on ISRO's Chandrayaan-1 and NASA's Lunar Reconnaissance Orbiter (LRO) obtained S band (12.6 cm) synthetic aperture radar images of the impact site at 150 and 30…
The nature of nuclear Hα emission in LINERs
González-Martín, O.; Márquez, I.; Masegosa, J. +1 more
To get insight into the nature of the ionized gas in the nuclear region of LINERs, we performed a study of HST Hα imaging of 32 LINERs. The main conclusion from this analysis is that, for the large majority of LINERs (84%), an unresolved nuclear source has been identified along with extended emission with equivalent sizes ranging from a few tens t…
What do Spectral Line Profile Asymmetries Tell us About the Solar Atmosphere?
Martínez-Sykora, Juan; De Pontieu, Bart; Hansteen, Viggo +1 more
Recently, analysis of solar spectra obtained with the EUV Imaging Spectrograph (EIS) onboard the Hinode satellite has revealed the ubiquitous presence of asymmetries in transition region (TR) and coronal spectral line profiles. These asymmetries have been observed especially at the footpoints of coronal loops and have been associated with strong u…
Polar coronal holes during the past solar cycle: Ulysses observations
Zurbuchen, Thomas H.; von Steiger, Rudolf
During its nearly 19-year mission, Ulysses pioneered novel measurements of the three-dimensional heliosphere and particularly in situ observations of high-latitude solar wind from polar coronal holes (PCHs). Winds from PCHs exhibit constant elemental abundances to within the limits of the measurements, indicative of the fact that such winds truly …
Probing the GC-LMXB Connection in NGC 1399: A Wide-field Study with the Hubble Space Telescope and Chandra
Kundu, Arunav; Zepf, Stephen E.; Maccarone, Thomas J. +5 more
We present a wide-field study of the globular cluster (GC)/low-mass X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The large field of view of the Advanced Camera for Surveys/WFC, combined with Hubble Space Telescope and Chandra high resolution, allow us to constrain the LMXB formation scenarios in elliptical galaxies. We confirm …
Some Characteristics of the Ionospheric Behavior During the Solar Cycle 23 - 24 Minimum
Araujo-Pradere, Eduardo A.; Redmon, Rob; Fedrizzi, Mariangel +2 more
The Solar Cycle 23 - 24 minimum has been considered unusually deep and complex. In this article we study the ionospheric behavior during this minimum, and we have found that, although observable, the ionosphere response is minor and marginally exceeds the range of normal geophysical variability of the system. Two main ionospheric parameters have b…
Quiescent X-ray variability from the neutron star transient Aql X-1
Wijnands, R.; Miller, J. M.; Homan, J. +2 more
A number of studies have revealed variability from neutron star low-mass X-ray binaries during quiescence. Such variability is not well characterized, or understood, but may be a common property that has been missed due to lack of multiple observations. One such source where variability has been observed is Aql X-1. Here, we analyse 14 Chandra and…
Nonlinear Color-Metallicity Relations of Globular Clusters. III. On the Discrepancy in Metallicity between Globular Cluster Systems and Their Parent Elliptical Galaxies
Peng, Eric W.; Blakeslee, John P.; Sohn, Sangmo T. +7 more
One of the conundrums in extragalactic astronomy is the discrepancy in observed metallicity distribution functions (MDFs) between the two prime stellar components of early-type galaxies—globular clusters (GCs) and halo field stars. This is generally taken as evidence of highly decoupled evolutionary histories between GC systems and their parent ga…
Influence of the scar geometry on landslide dynamics and deposits: Application to Martian landslides
Lucas, Antoine; Mège, Daniel; Mangeney, Anne +1 more
Landslides dynamics prediction remains difficult in spite of a considerable number of studies. The runout distance is widely used in analysis of landslide dynamics and in the calibration of the rheological parameters involved in numerical modeling. However, the unknown impact of the significant uncertainty in the shape of the initial released mass…