537 research outputs found
Gravitational lens candidates in the E-CDFS
We report ten lens candidates in the E-CDFS from the GEMS survey. Nine of the
systems are new detections and only one of the candidates is a known lens
system. For the most promising five systems including the known lens system, we
present results from preliminary lens mass modelling, which tests if the
candidates are plausible lens systems. Photometric redshifts of the candidate
lens galaxies are obtained from the COMBO-17 galaxy catalog. Stellar masses of
the candidate lens galaxies within the Einstein radius are obtained by using
the -band luminosity and the color-based stellar mass-to-light ratios.
As expected, the lensing masses are found to be larger than the stellar masses
of the candidate lens galaxies. These candidates have similar dark matter
fractions as compared to lenses in SLACS and COSMOS. They also roughly follow
the halo mass-stellar mass relation predicted by the subhalo abundance matching
technique. One of the candidate lens galaxies qualifies as a LIRG and may not
be a true lens because the arc-like feature in the system is likely to be an
active region of star formation in the candidate lens galaxy. Amongst the five
best candidates, one is a confirmed lens system, one is a likely lens system,
two are less likely to be lenses and the status of one of the candidates is
ambiguous. Spectroscopic follow-up of these systems is still required to
confirm lensing and/or for more accurate determination of the lens masses and
mass density profiles.Comment: 12 pages, 5 figures, 3 tables, ApJ accepte
Recommended from our members
The Popular Press and Ideas of Europe: The Daily Mirror, the Daily Express, and Britain's First Application to Join the EEC, 1961-63
This article shows how the popular press debate over Europe was fundamentally conditioned by the wider political, social, and cultural tensions of early 1960s Britain. By asking how the Daily Express and the Daily Mirror came to represent almost diametrically opposed views on Europe when both reached out to broadly comparable mass readerships, it exposes the many diverse and often contradictory responses that the far-reaching domestic and international transformations of post-war Britain provoked in the public discourse over Europe. Yet, while the Express’s opposition to the British application, based on its conservative and imperialist self-identity, has often been highlighted, the Mirror’s strong support of European integration, as part of its wider agenda for social and cultural change, has been all but ignored. Thus, the article exposes a previously overlooked line of public engagement with Europe at that time: through the eyes of the young, affluent consumer, unmoved by the claims of ‘tradition’
Basement and Regional Structure Along Strike of the Queen Charlotte Fault in the Context of Modern and Historical Earthquake Ruptures
The Queen Charlotte fault (QCF) is a dextral transform system located offshore of southeastern Alaska and western Canada, accommodating similar to 4.4 cm/yr of relative motion between the Pacific and North American plates. Oblique convergence along the fault increases southward, and how this convergence is accommodated is still debated. Using seismic reflection data, we interpret offshore basement structure, faulting, and stratigraphy to provide a geological context for two recent earthquakes, an M-w 7.5 strike-slip event near Craig, Alaska, and an M-w 7.8 thrust event near Haida Gwaii, Canada. We map downwarped Pacific oceanic crust near 54 degrees N, between the two rupture zones. Observed downwarping decreases north and south of 54 degrees N, parallel to the strike of the QCF. Bending of the Pacific plate here may have initiated with increased convergence rates due to a plate motion change at similar to 6 Ma. Tectonic reconstruction implies convergence-driven Pacific plate flexure, beginning at 6 Ma south of a 10 degrees bend the QCF (which is currently at 53.2 degrees N) and lasting until the plate translated past the bend by similar to 2 Ma. Normal-faulted approximately late Miocene sediment above the deep flexural depression at 54 degrees N, topped by relatively undeformed Pleistocene and younger sediment, supports this model. Aftershocks of the Haida Gwaii event indicate a normal-faulting stress regime, suggesting present-day plate flexure and underthrusting, which is also consistent with reconstruction of past conditions. We thus favor a Pacific plate underthrusting model to initiate flexure and accommodation space for sediment loading. In addition, mapped structures indicate two possible fault segment boundaries along the QCF at 53.2 degrees N and at 56 degrees N.USGS Earthquake Hazards External Grants ProgramNational Earthquake Hazards Reduction ProgramUTIG Ewing/Worzel FellowshipInstitute for Geophysic
Intensity of parasitic mite infection decreases with hibernation duration of the host snail
Temperature can be a limiting factor on parasite development. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. The prevalence of infection by R. limacum in populations of the land snail Arianta arbustorum is highly variable (0-78%) in Switzerland. However, parasitic mites do not occur in host populations at altitudes of 1290 m or higher. It has been hypothesized that the host's hibernation period might be too long at high elevations for mites and their eggs to survive. To test this hypothesis, we experimentally infected snails and allowed them to hibernate at 4°C for periods of 4-7 months. Winter survival of host snails was negatively affected by R. limacum. The intensity of mite infection decreased with increasing hibernation duration. Another experiment with shorter recording intervals revealed that mites do not leave the host when it buries in the soil at the beginning of hibernation. The number of mites decreased after 24 days of hibernation, whereas the number of eggs attached to the lung tissue remained constant throughout hibernation. Thus, R. limacum survives the winter in the egg stage in the host. Low temperature at high altitudes may limit the occurrence of R. limacu
Tsunamigenic Splay Faults Imply a Long‐Term Asperity in Southern Prince William Sound, Alaska
Coseismic slip partitioning and uplift over multiple earthquake cycles is critical to understanding upper‐plate fault development. Bathymetric and seismic reflection data from the 1964 Mw9.2 Great Alaska earthquake rupture area reveal sea floor scarps along the tsunamigenic Patton Bay/Cape Cleare/Middleton Island fault system. The faults splay from a megathrust where duplexing and underplating produced rapid exhumation. Trenchward of the duplex region, the faults produce a complex deformation pattern from oblique, south‐directed shortening at the Yakutat‐Pacific plate boundary. Spatial and temporal fault patterns suggest that Holocene megathrust earthquakes had similar relative motions and thus similar tsunami sources as in 1964. Tsunamis during future earthquakes will likely produce similar run‐up patterns and travel times. Splay fault surface expressions thus relate to plate boundary conditions, indicating millennial‐scale persistence of this asperity. We suggest structure of the subducted slab directly influences splay fault and tsunami generation landward of the frontal subduction zone prism
Onset of slow dynamics in difluorotetrachloroethane glassy crystal
Complementary Neutron Spin Echo and X-ray experiments and Molecular Dynamics
simulations have been performed on difluorotetrachloroethane (CFCl2-CFCl2)
glassy crystal. Static, single-molecule reorientational dynamics and collective
dynamics properties are investigated. The orientational disorder is
characterized at different temperatures and a change in nature of rotational
dynamics is observed. We show that dynamics can be described by some scaling
predictions of the Mode Coupling Theory (MCT) and a critical temperature
is determined. Our results also confirm the strong analogy between
molecular liquids and plastic crystals for which -relaxation times and
non-ergodicity parameters are controlled by the non trivial static correlations
as predicted by MCT
Behavior change training for pregnant women's communication during birth: A randomized controlled trial.
Applying health psychological theories can improve communication interventions to empower pregnant women and ensure safe births. The aim was to test a short digital communication intervention based on the health action process approach. A randomized-controlled trial was conducted with pregnant women at two German university hospitals. The intervention group (NT1 = 225; NT2 = 142) received a 2.5 h online training focusing on communication planning, self-efficacy and communicating personal needs and preferences under difficult circumstances. This group was compared with a passive control group (NT1 = 199; NT2 = 144). Data from the N = 286 women with complete datasets were used for multilevel analyses. Data from all recruited N = 424 women were used for intention-to-treat analyses with multiple imputation. Both groups improved regarding communication behavior, quality of birth, action planning, coping planning and coping self-efficacy after birth, which was more pronounced in the intervention group. The intention-to-treat analyses confirmed the higher improvement for communication behavior, perceived quality of birth and coping planning. The intervention was related to improvements in pregnant women's communication behavior and quality of birth. Hence, future research and practice should apply and evaluate health psychological theories when targeting communication and empowerment
Upper-Plate Structure and Tsunamigenic Faults Near the Kodiak Islands, Alaska, USA
The Kodiak Islands lie near the southern terminus of the 1964 Great Alaska earthquake rupture area and within the Kodiak subduction zone segment. Both local and trans-Pacific tsunamis were generated during this devastating megathrust event, but the local tsunami source region and the causative faults are poorly understood. We provide an updated view of the tsunami and earthquake hazard for the Kodiak Islands region through tsunami modeling and geophysical data analysis. Using seismic and bathymetric data, we characterize a regionally extensive seafloor lineament related to the Kodiak shelf fault zone, with focused uplift along a 50-km-long portion of the newly named Ugak fault as the most likely source of the local Kodiak Islands tsunami in 1964. We present evidence of Holocene motion along the Albatross Banks fault zone, but we suggest that this fault did not produce a tsunami in 1964. We relate major structural boundaries to active forearc splay faults, where tectonic uplift is collocated with gravity lineations. Differences in interseismic locking, seismicity rates, and potential field signatures argue for different stress conditions at depth near presumed segment boundaries. We find that the Kodiak segment boundaries have a clear geophysical expression and are linked to upper-plate structure and splay faulting. The tsunamigenic fault hazard is higher for the Kodiak shelf fault zone when compared to the nearby Albatross Banks fault zone, suggesting short wave travel paths and little tsunami warning time for nearby communities
Megathrust Splay Faults at the Focus of the Prince William Sound Asperity, Alaska
[1] High-resolution sparker and crustal-scale air gun seismic reflection data, coupled with repeat bathymetric surveys, document a region of repeated coseismic uplift on the portion of the Alaska subduction zone that ruptured in 1964. This area defines the western limit of Prince William Sound. Differencing of vintage and modern bathymetric surveys shows that the region of greatest uplift related to the 1964 Great Alaska earthquake was focused along a series of subparallel faults beneath Prince William Sound and the adjacent Gulf of Alaska shelf. Bathymetric differencing indicates that 12 m of coseismic uplift occurred along two faults that reached the seafloor as submarine terraces on the Cape Cleare bank southwest of Montague Island. Sparker seismic reflection data provide cumulative Holocene slip estimates as high as 9 mm/yr along a series of splay thrust faults within both the inner wedge and transition zone of the accretionary prism. Crustal seismic data show that these megathrust splay faults root separately into the subduction zone décollement. Splay fault divergence from this megathrust correlates with changes in midcrustal seismic velocity and magnetic susceptibility values, best explained by duplexing of the subducted Yakutat terrane rocks above Pacific plate rocks along the trailing edge of the Yakutat terrane. Although each splay fault is capable of independent motion, we conclude that the identified splay faults rupture in a similar pattern during successive megathrust earthquakes and that the region of greatest seismic coupling has remained consistent throughout the Holocene
- …