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Frederic Pont - One of the best experts on this subject based on the ideXlab platform.
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Temperature pressure Profile of the hot jupiter hd 189733b from hst sodium observations detection of upper atmospheric heating
Monthly Notices of the Royal Astronomical Society, 2012Co-Authors: Catherine M Huitson, David K Sing, A Vidalmadjar, Gilda E Ballester, Jeanmichel Desert, Lecavelier Des A Etangs, Frederic PontAbstract:We present transmission spectra of the hot Jupiter HD 189733b taken with the Space Telescope Imaging Spectrograph (STIS) aboard Hubble Space Telescope (HST). The spectra cover the wavelength range 5808–6380 A with a resolving power of R= 5000. We detect absorption from the Na i doublet within the exoplanet’s atmosphere at the 9σ confidence level within a 5 A band (absorption depth 0.09 ± 0.01 per cent) and use the data to measure the doublet’s spectral absorption Profile. We detect only the narrow cores of the doublet. The narrowness of the feature could be due to an obscuring high-altitude haze of an unknown composition or a significantly sub-solar Na i abundance hiding the line wings beneath an H2 Rayleigh signature. These observations are consistent with previous broad-band spectroscopy from Advanced Camera for Surveys (ACS) and STIS, where a featureless spectrum was seen. We also investigate the effects of starspots on the Na i line Profile, finding that their impact is minimal and within errors in the sodium feature. We compare the spectral absorption Profile over 5.5 scale heights with model spectral absorption Profiles and constrain the Temperature at different atmospheric regions, allowing us to construct a Vertical Temperature Profile. We identify two Temperature regimes: a 1280 ± 240 K region derived from the Na i doublet line wings corresponding to altitudes below ∼500 km, and a 2800 ± 400 K region derived from the Na i doublet line cores corresponding to altitudes from ∼500 to 4000 km. The zero altitude is defined by the white-light radius of RP/R★= 0.15628 ± 0.00009. The Temperature rises with altitude, which is likely evidence of a thermosphere. The absolute pressure scale depends on the species responsible for the Rayleigh signature and its abundance. We discuss a plausible scenario for this species, a high-altitude silicate haze and the atmospheric Temperature–pressure Profile that results. In this case, the high-altitude Temperature rise for HD 189733b occurs at pressures of 10−5 to 10−8 bar.
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Temperature pressure Profile of the hot jupiter hd 189733b from hst sodium observations detection of upper atmospheric heating
arXiv: Earth and Planetary Astrophysics, 2012Co-Authors: Catherine M Huitson, David K Sing, A Vidalmadjar, Gilda E Ballester, Alain Lecavelier Des Etangs, Jeanmichel Desert, Frederic PontAbstract:We present transmission spectra of the hot Jupiter HD 189733b taken with the Space Telescope Imaging Spectrograph aboard HST. The spectra cover the wavelength range 5808-6380 Ang with a resolving power of R=5000. We detect absorption from the NaI doublet within the exoplanet's atmosphere at the 9 sigma confidence level within a 5 Ang band (absorption depth 0.09 +/- 0.01%) and use the data to measure the doublet's spectral absorption Profile. We detect only the narrow cores of the doublet. The narrowness of the feature could be due to an obscuring high-altitude haze of an unknown composition or a significantly sub-solar NaI abundance hiding the line wings beneath a H2 Rayleigh signature. We compare the spectral absorption Profile over 5.5 scale heights with model spectral absorption Profiles and constrain the Temperature at different atmospheric regions, allowing us to construct a Vertical Temperature Profile. We identify two Temperature regimes; a 1280 +/- 240 K region derived from the NaI doublet line wings corresponding to altitudes below ~ 500 km, and a 2800 +/- 400 K region derived from the NaI doublet line cores corresponding to altitudes from ~ 500-4000 km. The zero altitude is defined by the white-light radius of Rp/Rstar=0.15628 +/- 0.00009. The Temperature rises with altitude, which is likely evidence of a thermosphere. The absolute pressure scale depends on the species responsible for the Rayleigh signature and its abundance. We discuss a plausible scenario for this species, a high-altitude silicate haze, and the atmospheric Temperature-pressure Profile that results. In this case, the high altitude Temperature rise for HD 189733b occurs at pressures of 10^-5 to 10^-8 bar.
Jason T Wright - One of the best experts on this subject based on the ideXlab platform.
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evidence for atmospheric cold trap processes in the noninverted emission spectrum of kepler 13ab using hst wfc3
The Astronomical Journal, 2017Co-Authors: Thomas G Beatty, Heather A Knutson, Nikku Madhusudhan, Angelos Tsiaras, Ming Zhao, Ronald L Gilliland, Avi Shporer, Jason T WrightAbstract:We observed two eclipses of the Kepler-13A planetary system, on UT 2014 April 28 and UT 2014 October 13, in the near-infrared using Wide Field Camera 3 on the Hubble Space Telescope. By using the nearby binary stars Kepler-13BC as a reference, we were able to create a differential light curve for Kepler-13A that had little of the systematics typically present in HST/WFC3 spectrophotometry. We measure a broadband (1.1–1.65 μm) eclipse depth of 734 ± 28 ppm and are able to measure the emission spectrum of the planet at R ≈ 50 with an average precision of 70 ppm. We find that Kepler-13Ab possesses a noninverted, monotonically decreasing Vertical Temperature Profile. We exclude an isothermal Profile and an inverted Profile at more than 3σ. We also find that the dayside emission of Kepler-13Ab appears generally similar to an isolated M7 brown dwarf at a similar effective Temperature. Due to the relatively high mass and surface gravity of Kepler-13Ab, we suggest that the apparent lack of an inversion is due to cold-trap processes in the planet's atmosphere. Using a toy model for where cold traps should inhibit inversions, as well as observations of other planets in this Temperature range with measured emission spectra, we argue that with more detailed modeling and more observations we may be able to place useful constraints on the size of condensates on the daysides of hot Jupiters.
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evidence for atmospheric cold trap processes in the noninverted emission spectrum of kepler 13ab using hst wfc3
arXiv: Earth and Planetary Astrophysics, 2016Co-Authors: Thomas G Beatty, Heather A Knutson, Nikku Madhusudhan, Angelos Tsiaras, Ming Zhao, Ronald L Gilliland, Avi Shporer, Jason T WrightAbstract:We observed two eclipses of the Kepler-13A planetary system, on UT 2014 April 28 and UT 2014 October 13, in the near-infrared using Wide Field Camera 3 on the Hubble Space Telescope. By using the nearby binary stars Kepler-13BC as a reference, we were able to create a differential light curve for Kepler-13A that had little of the systematics typically present in HST/WFC3 spectrophotometry. We measure a broadband (1.1$\mu$m to 1.65$\mu$m) eclipse depth of $734\pm28$ ppm, and are able to measure the emission spectrum of the planet at $R\approx50$ with an average precision of 70 ppm. We find that Kepler-13Ab possesses a noninverted, monotonically decreasing Vertical Temperature Profile. We exclude an isothermal Profile and an inverted Profile at more than 3$\sigma$. We also find that the dayside emission of Kepler-13Ab appears generally similar to an isolated M7 brown dwarf at a similar effective Temperature. Due to the relatively high mass and surface gravity of Kepler-13Ab, we suggest that the apparent lack of an inversion is due to cold-trap processes in the planet's atmosphere. Using a toy model for where cold-traps should inhibit inversions, and observations of other planets in this Temperature range with measured emission spectra, we argue that with more detailed modeling and more observations we may be able to place useful constraints on the size of condensates on the daysides of hot Jupiters.
Haowen Tao - One of the best experts on this subject based on the ideXlab platform.
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investigation on Vertical Temperature Profile of thermal ejected plume from a compartment fire with an adjacent side wall
International Journal of Thermal Sciences, 2021Co-Authors: Fang Gan, Yahong Yang, Jin Zhu, Haowen TaoAbstract:Abstract This paper presents an investigation of Vertical Temperature Profile of the thermal ejected plume from a compartment fire with an adjacent side wall, which has not been quantified in the literatures. A full-scale compartment model with a Vertical facade and an adjacent side wall positioned at the side of the window has been set up in the numerical simulations. The Vertical Temperature distribution upon the facade with various window dimensions, total heat release rates and side wall separation distances is measured. By comparing with former study, the validity of the numerical simulation results has been confirmed, which shows good agreement with the previous experimental data. Result reveals that only when the side wall separation distance (D) is less than a critical value for each window dimension, will the Vertical Temperature Profile of thermal ejected plume affect by the constraining boundary of adjacent side wall, otherwise it will remain basically the same. Then, a new correlation is proposed to describe the constraining effect of side wall on the Vertical Temperature Profile by introducing a coefficient α . Numerical simulation results for various window dimensions, total heat release rates and side wall separation distances can be well collapsed by the newly proposed correlation.
Catherine M Huitson - One of the best experts on this subject based on the ideXlab platform.
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Temperature pressure Profile of the hot jupiter hd 189733b from hst sodium observations detection of upper atmospheric heating
Monthly Notices of the Royal Astronomical Society, 2012Co-Authors: Catherine M Huitson, David K Sing, A Vidalmadjar, Gilda E Ballester, Jeanmichel Desert, Lecavelier Des A Etangs, Frederic PontAbstract:We present transmission spectra of the hot Jupiter HD 189733b taken with the Space Telescope Imaging Spectrograph (STIS) aboard Hubble Space Telescope (HST). The spectra cover the wavelength range 5808–6380 A with a resolving power of R= 5000. We detect absorption from the Na i doublet within the exoplanet’s atmosphere at the 9σ confidence level within a 5 A band (absorption depth 0.09 ± 0.01 per cent) and use the data to measure the doublet’s spectral absorption Profile. We detect only the narrow cores of the doublet. The narrowness of the feature could be due to an obscuring high-altitude haze of an unknown composition or a significantly sub-solar Na i abundance hiding the line wings beneath an H2 Rayleigh signature. These observations are consistent with previous broad-band spectroscopy from Advanced Camera for Surveys (ACS) and STIS, where a featureless spectrum was seen. We also investigate the effects of starspots on the Na i line Profile, finding that their impact is minimal and within errors in the sodium feature. We compare the spectral absorption Profile over 5.5 scale heights with model spectral absorption Profiles and constrain the Temperature at different atmospheric regions, allowing us to construct a Vertical Temperature Profile. We identify two Temperature regimes: a 1280 ± 240 K region derived from the Na i doublet line wings corresponding to altitudes below ∼500 km, and a 2800 ± 400 K region derived from the Na i doublet line cores corresponding to altitudes from ∼500 to 4000 km. The zero altitude is defined by the white-light radius of RP/R★= 0.15628 ± 0.00009. The Temperature rises with altitude, which is likely evidence of a thermosphere. The absolute pressure scale depends on the species responsible for the Rayleigh signature and its abundance. We discuss a plausible scenario for this species, a high-altitude silicate haze and the atmospheric Temperature–pressure Profile that results. In this case, the high-altitude Temperature rise for HD 189733b occurs at pressures of 10−5 to 10−8 bar.
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Temperature pressure Profile of the hot jupiter hd 189733b from hst sodium observations detection of upper atmospheric heating
arXiv: Earth and Planetary Astrophysics, 2012Co-Authors: Catherine M Huitson, David K Sing, A Vidalmadjar, Gilda E Ballester, Alain Lecavelier Des Etangs, Jeanmichel Desert, Frederic PontAbstract:We present transmission spectra of the hot Jupiter HD 189733b taken with the Space Telescope Imaging Spectrograph aboard HST. The spectra cover the wavelength range 5808-6380 Ang with a resolving power of R=5000. We detect absorption from the NaI doublet within the exoplanet's atmosphere at the 9 sigma confidence level within a 5 Ang band (absorption depth 0.09 +/- 0.01%) and use the data to measure the doublet's spectral absorption Profile. We detect only the narrow cores of the doublet. The narrowness of the feature could be due to an obscuring high-altitude haze of an unknown composition or a significantly sub-solar NaI abundance hiding the line wings beneath a H2 Rayleigh signature. We compare the spectral absorption Profile over 5.5 scale heights with model spectral absorption Profiles and constrain the Temperature at different atmospheric regions, allowing us to construct a Vertical Temperature Profile. We identify two Temperature regimes; a 1280 +/- 240 K region derived from the NaI doublet line wings corresponding to altitudes below ~ 500 km, and a 2800 +/- 400 K region derived from the NaI doublet line cores corresponding to altitudes from ~ 500-4000 km. The zero altitude is defined by the white-light radius of Rp/Rstar=0.15628 +/- 0.00009. The Temperature rises with altitude, which is likely evidence of a thermosphere. The absolute pressure scale depends on the species responsible for the Rayleigh signature and its abundance. We discuss a plausible scenario for this species, a high-altitude silicate haze, and the atmospheric Temperature-pressure Profile that results. In this case, the high altitude Temperature rise for HD 189733b occurs at pressures of 10^-5 to 10^-8 bar.
J Wang - One of the best experts on this subject based on the ideXlab platform.
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Vertical Temperature Profile of fire induced facade thermal plume ejected from a fire compartment window with two adjacent side walls
Applied Thermal Engineering, 2017Co-Authors: J WangAbstract:Abstract This work investigates the Vertical Temperature Profiles of fire-induced facade thermal plumes ejected from a compartment window with two adjacent side walls. A small-scale cubic compartment (1:8) with its window attached by a Vertical facade wall is employed. Two side walls are positioned symmetrically at the two sides of the window of the compartment. The compartment ventilation and side wall constraint conditions are varied by changing the window dimensions and the side wall separation distances during the experiments. K-type thermocouples are installed along the facade wall to measure the Vertical Temperature Profile. Results show that the Temperature at a given height increases with the decrease in side wall separation distance for a “(half) axisymmetric plume”, as the air entrainment into the plume is reduced with the presence of side walls. A global model is further developed, based on the change of the air entrainment (in relation to the separation distance of side walls, the characteristic length scales of the window and dimensionless excess heat release rate), to account for the side wall constraint effect on Vertical Temperature Profile upon the facade wall. Experimental data for various window dimensions and side wall separation distances are well correlated by the proposed model.