477 research outputs found
TEA: A Code for Calculating Thermochemical Equilibrium Abundances
We present an open-source Thermochemical Equilibrium Abundances (TEA) code
that calculates the abundances of gaseous molecular species. The code is based
on the methodology of White et al. (1958) and Eriksson (1971). It applies Gibbs
free-energy minimization using an iterative, Lagrangian optimization scheme.
Given elemental abundances, TEA calculates molecular abundances for a
particular temperature and pressure or a list of temperature-pressure pairs. We
tested the code against the method of Burrows & Sharp (1999), the free
thermochemical equilibrium code CEA (Chemical Equilibrium with Applications),
and the example given by White et al. (1958). Using their thermodynamic data,
TEA reproduces their final abundances, but with higher precision. We also
applied the TEA abundance calculations to models of several hot-Jupiter
exoplanets, producing expected results. TEA is written in Python in a modular
format. There is a start guide, a user manual, and a code document in addition
to this theory paper. TEA is available under a reproducible-research,
open-source license via https://github.com/dzesmin/TEA.Comment: 14 pages, 8 figures, article is submitted to ApJS, posted on arXiv
for public commentary, please send comments to the lead autho
Observations, Thermochemical Calculations, and Modeling of Exoplanetary Atmospheres
This dissertation as a whole aims to provide means to better understand
hot-Jupiter planets through observing, performing thermochemical calculations,
and modeling their atmospheres. We used Spitzer multi-wavelength
secondary-eclipse observations and targets with high signal-to-noise ratios, as
their deep eclipses allow us to detect signatures of spectral features and
assess planetary atmospheric structure and composition with greater certainty.
Chapter 1 gives a short introduction. Chapter 2 presents the Spitzer
secondary-eclipse analysis and atmospheric characterization of WASP-14b.
WASP-14b is a highly irradiated, transiting hot Jupiter. By applying a Bayesian
approach in the atmospheric analysis, we found an absence of thermal inversion
contrary to theoretical predictions. Chapter 3 describes the infrared
observations of WASP-43b Spitzer secondary eclipses, data analysis, and
atmospheric characterization. WASP-43b is one of the closest-orbiting hot
Jupiters, orbiting one of the coolest stars with a hot Jupiter. The atmospheric
analysis ruled out a strong thermal inversion in its dayside atmosphere.
Chapter 4 presents an open-source Thermochemical Equilibrium Abundances (TEA)
code and its application to several hot Jupiters. TEA calculates the abundances
of gaseous species using the Gibbs free-energy minimization method within an
iterative Lagrangian optimization scheme. The code is written in Python and
available to the community via http://github.com/dzesmin/TEA. Chapter 5
presents my contributions to an open-source Bayesian Atmospheric Radiative
Transfer (BART) code, and its application to WASP-43b. BART characterizes
planetary atmospheres based on the observed spectroscopic information. It
initializes a planetary atmospheric model, performs radiative-transfer
calculations to produce models of planetary spectra, and using a statistical
module compares models with observations.Comment: Ph.D. Dissertatio
Observations, Thermochemical Calculations, and Modeling of Exoplanetary Atmospheres
This dissertation as a whole aims to provide the means to better understand hot-Jupiter planets through observing, performing thermochemical calculations, and modeling their atmospheres. We used Spitzer multi-wavelength secondary-eclipse observations to characterize planetary atmospheres. We chose targets with high signal-to-noise ratios, as their deep eclipses allow us to detect signatures of spectral features and assess planetary atmospheric structure and composition with greater certainty. Chapter 1 gives a short introduction. Chapter 2 presents the Spitzer secondary-eclipse analysis and atmospheric characterization of WASP-14b. The decrease in flux when a planet passes behind its host star reveals the planet dayside thermal emission, which, in turn, tells us about the atmospheric temperature and pressure profiles and molecular abundances. WASP-14b is a highly irradiated, transiting hot Jupiter. By applying a Bayesian approach in the atmospheric analysis, we found an absence of thermal inversion contrary to theoretical predictions. Chapter 3 describes the infrared observations of WASP-43b\u27s Spitzer secondary eclipses, data analysis, and atmospheric characterization. WASP-43b is one of the closest-orbiting hot Jupiters, orbiting one of the coolest stars with a hot Jupiter. This configuration provided one of the strongest signal-to-noise ratios. The atmospheric analysis ruled out a strong thermal inversion in the dayside atmosphere of WASP-43b and put a nominal upper limit on the day-night energy redistribution. Chapter 4 presents an open-source Thermochemical Equilibrium Abundances (TEA) code and its application to several hot-Jupiter temperature and pressure models. TEA calculates the abundances of gaseous molecular species using the Gibbs free-energy minimization method within an iterative Lagrangian optimization scheme. The thermochemical equilibrium abundances obtained with TEA can be used to initialize atmospheric models of any planetary atmosphere. The code is written in Python, in a modular fashion, and it is available to the community via http://github.com/dzesmin/TEA. Chapter 5 presents my contributions to an open-source Bayesian Atmospheric Radiative Transfer (BART) code, and its application to WASP-43b. BART characterizes planetary atmospheres based on the observed spectroscopic information. It initializes a planetary atmospheric model, performs radiative-transfer calculations to produce models of planetary spectra, and using a statistical module compares models with observations. We describe the implementation of the initialization routines, the atmospheric profile generator, the eclipse module, the best-fit routines, and the contribution function module. We also present a comprehensive atmospheric analysis of all WASP-43b secondary-eclipse data obtained from the space- and ground-based observations using BART
Point of Care Tools and Libraries: 12th Annual Health Sciences Lively Lunch
This session included a discussion about point of care tools in the health information setting. Klimley provided a presentation on the point of care tools landscape that highlighted the importance and relevance of this topic now, evaluations that have been published about these tools, funding issues, and desirable elements of the tools. The presentation included examples of marketing techniques and product advertisements to portray the various claims and testimonials regarding these products, which provided a critical discussion on the products and their use in health information settings. A lively discussion followed the presentation to allow participants to express some of their concerns about point of care tools and their role in the future. The results of the session are explained in the document
The Invisible Women: The Taliban\u27s Oppression Of Women In Afghanistan
Today, we live in a world where the women\u27s movement has given most women the opportunity to excel in professional careers, hold political offices, own their own companies, and hold many other positions of power
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