1,766 research outputs found
On the heat redistribution of the hot transiting exoplanet WASP-18b
The energy deposition and redistribution in hot Jupiter atmospheres is not
well understood currently, but is a major factor for their evolution and
survival. We present a time dependent radiative transfer model for the
atmosphere of WASP-18b which is a massive (10 MJup) hot Jupiter (Teq ~ 2400 K)
exoplanet orbiting an F6V star with an orbital period of only 0.94 days. Our
model includes a simplified parametrisation of the day-to-night energy
redistribution by a modulation of the stellar heating mimicking a solid body
rotation of the atmosphere. We present the cases with either no rotation at all
with respect to the synchronously rotating reference frame or a fast
differential rotation. The results of the model are compared to previous
observations of secondary eclipses of Nymeyer et al. (2011) with the Spitzer
Space Telescope. Their observed planetary flux suggests that the efficiency of
heat distribution from the day-side to the night-side of the planet is
extremely inefficient. Our results are consistent with the fact that such large
day-side fluxes can be obtained only if there is no rotation of the atmosphere.
Additionally, we infer light curves of the planet for a full orbit in the two
Warm Spitzer bandpassses for the two cases of rotation and discuss the
observational differences.Comment: 4 figures, accepted for publication in Icaru
A Time-Dependent Model of HD209458b
We developed a time-dependent radiative model for the atmosphere of HD209458b
to investigate its thermal structure and chemical composition. Time-dependent
temperature profiles were calculated, using a uniform zonal wind modelled as a
solid body rotation. We predict day/night temperature variations of 600K around
0.1 bar, for a 1 km/s wind velocity, in good agreement with the predictions by
Showman & Guillot (2002). On the night side, the low temperature allows the
sodium to condense. Depletion of sodium in the morning limb may explain the
lower than expected abundance found by Charbonneau et al (2002).Comment: 2 pages, LaTeX with 1 EPS figure embedded, using newpasp.sty
(supplied). To appear in the proceedings of the XIXth IAP colloquium
"Extrasolar Planets: Today and Tomorrow" held in Paris, France, 2003 June 30
-- July 4, ASP Conf. Se
CNN-SLAM: Real-time dense monocular SLAM with learned depth prediction
Given the recent advances in depth prediction from Convolutional Neural
Networks (CNNs), this paper investigates how predicted depth maps from a deep
neural network can be deployed for accurate and dense monocular reconstruction.
We propose a method where CNN-predicted dense depth maps are naturally fused
together with depth measurements obtained from direct monocular SLAM. Our
fusion scheme privileges depth prediction in image locations where monocular
SLAM approaches tend to fail, e.g. along low-textured regions, and vice-versa.
We demonstrate the use of depth prediction for estimating the absolute scale of
the reconstruction, hence overcoming one of the major limitations of monocular
SLAM. Finally, we propose a framework to efficiently fuse semantic labels,
obtained from a single frame, with dense SLAM, yielding semantically coherent
scene reconstruction from a single view. Evaluation results on two benchmark
datasets show the robustness and accuracy of our approach.Comment: 10 pages, 6 figures, IEEE Computer Society Conference on Computer
Vision and Pattern Recognition (CVPR), Hawaii, USA, June, 2017. The first two
authors contribute equally to this pape
Apathy or lack of civic education? Why young people donât vote
The consistently low turnout rates among young people are often interpreted as apathy. But this is not the case, explains Iro Konstantinou. She writes that the curriculum must be widened to include more practical democratic issues than just traditional party politics, and take into account the socio-economic background of students so that it talks about the social issues that matter to them
Book review: medicine at the border: disease, globalization and security, 1850 to the present, edited by Alison Bashford
Medicine at the Border looks to explore the pressing issues of border control and infectious disease in the nineteenth, twentieth, and twenty-first centuries. Chapters cover mandatory HIV testing, the formation of the WHO, and biosecurity and public health governance. Iro Filippaki recommends this collection to health researchers and historians
Synthesis, characterisation and testing of Au/SBA-15 catalysts for elimination of volatile organic compounds by complete oxidation at low temperatures
Determining Causes of Gully Erosion and Associated Rates of Change in South-East Nigeria, using a Remote Sensing and GIS Methodology
Book review: asexuality and sexual normativity: an anthology edited by Mark Carrigan et al.
The last decade has seen the emergence of an increasingly politically active asexual community, united around a common identity as âpeople who do not experience sexual attractionâ. This collection covers the emergence of the concept of ânormalâ sexuality in the late eighteenth-century, early-twentieth-century public sex education campaigns, and how asexuality is different from hypoactive sexual desire disorder. Iro Filippaki finds that each and every one of the articles truly contributes to the disambiguation of the notion of asexuality in the present
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