Near-infrared integral field spectroscopy of the Homunculus nebula around η Carinae using Gemini/cirpass

This work presents the first integral field spectroscopy of the Homunculus nebula around η Carinae in the near-infrared spectral region ( J band). We confirmed the presence of a hole on the polar region of each lobe, as indicated by previous near-IR long-slit spectra and mid-IR images. The holes can be described as a cylinder of height (i.e. the thickness of the lobe) and diameter of 6.5 and  6.0 × 10¹⁶  cm, respectively. We also mapped the blue-shifted component of He  i  λ10830 seen towards the NW lobe. Contrary to previous works, we suggested that this blue-shifted component is not related to the Paddle but it is indeed in the equatorial disc.
We confirmed the claim of N. Smith and showed that the spatial extent of the Little Homunculus matches remarkably well the radio continuum emission at 3 cm, indicating that the Little Homunculus can be regarded as a small H  ii region. Therefore, we used the optically thin 1.3 mm radio flux to derive a lower limit for the number of Lyman-continuum photons of the central source in η Car. In the context of a binary system, and assuming that the ionizing flux comes entirely from the hot companion star, the lower limit for its spectral type and luminosity class ranges from O5.5  iii to O7  i . Moreover, we showed that the radio peak at 1.7 arcsec NW from the central star is in the same line-of-sight of the 'Sr-filament' but they are obviously spatially separated, while the blue-shifted component of He  i λ10830 may be related to the radio peak and can be explained by the ultraviolet radiation from the companion star.     

Low Perihelion Near-Earth Asteroids

We present initial results from a study of a sample of low-perihelion near-Earth asteroids (NEAs) using the Infrared Spectrograph (IRS) on NASA’s Spitzer Space Telescope. The 7–14 μm thermal emission spectra have been fitted with models of the thermal continuum to derive the asteroid’s effective diameter, geometric albedo and beaming parameter η. In this work, we concentrate on the thermal behavior and we find a trend of increasing η (lower thermal fluxes and cooler color temperatures) with increasing solar phase angle. The slope of this trend is somewhat different from that reported for other NEAs (e.g., Delbó 2004); if confirmed, this result would indicate that the thermal behavior of low-perihelion asteroids is different from that of other members of the NEA population. In addition, deviations of the observed continuum from the thermal model, which can be diagnostic of composition, are apparent in a few of our targets. A complete characterization of these intrinsically faint objects will benefit from the large ground based facilities described elsewhere in these proceedings.     

Long lasting interactions between tectonic loading, unroofing, post-rift thermal subsidence and sedimentary transfers along the western margin of the Gulf of Mexico: Some insights from integrated quantitative studies

After Jurassic rifting, numerous carbonate platforms (i.e., the Orizaba, Cordoba and Golden Lane-Tuxpan platforms) developed during the Lower and Middle Cretaceous episode of thermal subsidence along the western passive margin of the Gulf of Mexico, with intervening basinal domains (i.e., the Tampico-Misantla, Zongolica, Veracruz and Deep Gulf of Mexico - DGM - basins).During the Late Cretaceous-Paleocene, the east-verging Sierra Madre Oriental thrust belt developed, resulting in tectonic uplift and unroofing of the allochthonous units (i.e. tectonic units made up of former Orizaba and Cordoba platforms and Zongolica Basin series). This new topography provided also an important source of clastics to feed the adjacent foredeep, where coeval tectonic loading accounted for the bending of the foreland lithosphere. However, shallow water facies or even emersion persisted until the Eocene in the forebulge area (at the present location of the Golden Lane), preventing locally the clastics to reach the DGM. This topographic barrier was ultimately bypassed by the clastics only during the Oligocene and Neogene, once (1) the prograding clastic wedge had exceeded accommodation, and (2) the long lasting thermal subsidence of the passive margin could overpass the effect of the bending and force the former bulge to sink.Numerous paleo-thermo-meters (Tmax, Ro), paleo-thermo-barometers (fluid inclusions), PVT and coupled forward kinematic and thermal modeling have been used to calibrate and date the progressive unroofing of the thrust belt. Coupled tectonic and sedimentologic modeling was applied in the foreland to predict the distribution of sand versus shale ratios in the Oligocene to Plio-Quaternary clastic sedimentary wedge of the passive margin, where gravitational gliding of post-Eocene series occurred during the Neogene along major listric faults.Mantle dynamics are advocated as the main process accounting for post-orogenic uplift and regional tilting of the basement, which initiated a massive transfer of sediments from the Cordillera towards the Gulf of Mexico, from Oligocene onward, resulting in a destabilization and gravitational collapse of the western slope of the Gulf of Mexico in Neogene times.     

Influence of spatial variability of soil friction angle on sheet pile walls’ structural behaviour

The uncertainty in terms of soil characterisation is studied to assess its effect on the structural behaviour of extended structures as sheet pile walls. A finite element model is used. This integrates a numerical model of the soil–structure interaction together with a stochastic model that allows characterising the soil variability. The model serves in propagating the variability and the system parameter uncertainties. Discussion is mainly focused on two points: (1) testing the sensitivity of the structural behaviour of a sheet pile wall to different geotechnical parameters and (2) assessing the influence of spatial variability of soil properties on the structural behaviour by identifying the most sensitive geotechnical parameter and the most significant correlation length values. The findings showed that in assessing the sheet pile wall’s structural behaviour, there are spatial variability parameters that cannot be considered negligible. In this study, soil friction angle is found to be an important parameter.     

Square Kilometre Array: The radio telescope of the XXI century

The Square Kilometre Array (SKA) will be the world’s largest and most sensitive radio telescope. It will address fundamental unanswered questions about our Universe including how the first stars and galaxies formed after the Big Bang, how dark energy is accelerating the expansion of theUniverse, the role of magnetism in the cosmos, the nature of gravity, and the search for life beyond Earth. This project envisages the construction of 133 15-m antennas in South Africa and 131072 log-periodic antennas in Australia, together with the associated infrastructure in the two desert sites. In addition, the SKA is an exemplar Big Data project, with data rates of over 10 Tbps being transported from the telescope to HPC/HTC facilities.     

Incorporating inland flooding into hurricane evacuation decision support modeling

Natural Hazards - Formal engineering hurricane evacuation studies have not typically considered inland flooding explicitly, though it has been shown repeatedly to be a major cause of damage and...     

Land disposal of river and lagoon dredged sediments

The Jacarepaguá lagoon system, in the Western part of the city of Rio de Janeiro, Brazil, with an area of 8 km² receives the contributions of a number of rivers crossing largely populated and industrial areas without adequate sanitation and drainage. Since 1996 studies have been carried out to assist future dredging works and disposal of rivers and lagoons sediments. These studies included full characterization of these sediments and evaluation of the contamination of the dredged material with emphasis on the assessment of heavy metals. The present paper report these studies to assess a large dredging programme of about 3.8 million m³ of the river basins and 4 million m³ of lagoons sediments to be disposed inland.