36 research outputs found

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 ÎŒm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    Exploring new physics frontiers through numerical relativity

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    The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology

    Pain control is comparable between opioid versus non‐opioid management after otolaryngology procedures

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    Abstract Objective The current study aims to measure patient‐reported satisfaction with pain control using opioid and non‐opioid medications after undergoing the following otolaryngology procedures: parathyroidectomy, thyroid lobectomy, total thyroidectomy, and bilateral tonsillectomy. Materials and Methods A prospective cohort study was performed at an academic medical center that included a telephone questionnaire and chart review. Opioid prescriptions, usage, and patient‐reported pain outcomes were recorded. Bivariate analyses were used to compare opioid and non‐opioid users. Results Of the 107 total patients undergoing otolaryngology procedures included in the study, 49 (45.8%) used an opioid for pain management postoperatively and 58 (54.2%) did not. Among the 81 patients who underwent endocrine procedures (parathyroidectomy, total thyroidectomy/lobectomy), most patients reported being “very satisfied” or “satisfied” with pain control whether they used opioids (n = 27/30, 90%) or not (n = 50/51, 98%). Of the 26 patients who underwent bilateral tonsillectomy, 19 (73%) were prescribed opioids and among these, most (n = 17/19, 89%) reported they were “very satisfied” or “satisfied” with pain control. In the non‐opioid usage group, all patients (n = 7/7, 100%) reported they were “satisfied” with pain control. There was no statistically significant difference in patient‐reported satisfaction with pain control between opioid and non‐opioid users for any of the procedures listed. Conclusion The results of our study suggest that patients who did not use opioids have a similar level of satisfaction with pain control compared to those using opioids after thyroid, parathyroid and tonsillectomy surgeries. Considering the magnitude of the opioid crisis, providers should reassess the need for opioid prescriptions following certain ENT procedures. Level of Evidence IV
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