HD 179949b - a close orbiting extrasolar giant planet with a stratosphere?

The original article can be found at: http://www3.interscience.wiley.com Copyright Blackwell Publishing. DOI: 10.1111/j.1365-2966.2008.13831.xWe have carried out a search for the 2.14-μm spectroscopic signature of the close orbiting extrasolar giant planet, HD179949b. High-cadence time-series spectra were obtained with the Cryogenic high-resolution InfraRed ´ Echelle Spectrograph at Very Large Telescope, Unit 1 on two closely separated nights. Deconvolution yielded spectroscopic profiles with mean signal-to-noise ratios of several thousand, enabling the near-infrared contrast ratios predicted for the HD179949 system to be achieved. Recent models have predicted that the hottest planets may exhibit spectral signatures in emission due to the presence of TiO and VO which may be responsible for a temperature inversion high in the atmosphere.We have used our phase-dependent orbital model and tomographic techniques to search for the planetary signature under the assumption of an absorption line dominated atmospheric spectrum, where T and V are depleted from the atmospheric model, and an emission line dominated spectrum, where TiO and VO are present. We do not detect a planet in either case, but the 2.120–2.174-μm wavelength region covered by our observations enables the deepest near-infrared limits yet to be placed on the planet/star contrast ratio of any close orbiting extrasolar giant planet system. We are able to rule out the presence of an atmosphere dominated by absorption opacities in the case of HD179949b at a contrast ratio of Fp/F∗ ∼ 1/3350, with 99 per cent confidence.Peer reviewe

Effects of nuclear structure on average angular momentum in subbarrier fusion

We investigate the effects of nuclear quadrupole and hexadecapole couplings on the average angular momentum in sub-barrier fusion reactions. This quantity could provide a probe for nuclear shapes, distinguishing between prolate vs. oblate quadrupole and positive vs. negative hexadecapole couplings. We describe the data in the O + Sm system and discuss heavier systems where shape effects become more pronounced.Comment: Latex (uses the epsf macro), 10 pages of text, 3 postscript figures included. Full postscript version available by anonymous ftp from wisnuf.physics.wisc.edu:/pub/preprints. MAD-NT-94-0

Barrier Distributions as a Tool to Investigate Fusion and Fission

The recent availability of precisely measured fusion cross-sections has enabled the extraction of a representation of the distribution of barriers encountered during fusion. These representations, obtained from a variety of reactions, provide a direct observation of how the structure of the fusing nuclei changes the inter-nuclear potential landscape, thus affecting the fusion probability. Recent experiments showing the effects of static quadrupole and hexadecapole deformation, single-- and double-phonon states, transfer of nucleons between two nuclei, and high lying excited states are reviewed. The application of these concepts to the explanation of the anomalous fission-fragment anisotropies observed following reactions with actinides is discussed.Comment: 12 pages, To be published in the Proceedings of the NN 97 Conference, Gatlinburg, Tennessee, June 1997 (Nucl. Phys. A

The effect of trepanning speed of laser drilled acute angled cooling holes on the high temperature low cycle corrosion fatigue performance of CMSX-4 at 850 °C

The effect of laser trepanning speed and, as a result, recast layer thickness on the high temperature corrosion fatigue behaviour of CMSX-4 superalloy acute angled holes was investigated. The experimental test results show that an increasing laser drilling speed caused a reduction in corrosion fatigue life by 35–50% at 850 °C, under low cycle fatigue regime. This reduction was found to correlate directly with the recast layer thickness and surface anomalies within the recast layer produced during the laser drilling process. Corrosion had a smaller effect on the overall life of the laser drilled specimens under the conditions tested. The results presented show that laser trepanning speed is influential in limiting the life performance of laser drilled components in service

Fuzzy Rings in D6-Branes and Magnetic Field Background

We use the Myers T-dual nonabelin Born-Infeld action to find some new nontrivial solutions for the branes in the background of D6-branes and Melvin magnetic tube field. In the D6-Branes background we can find both of the fuzzy sphere and fuzzy ring solutions, which are formed by the gravitational dielectric effect. We see that the fuzzy ring solution has less energy then that of the fuzzy sphere. Therefore the fuzzy sphere will decay to the fuzzy ring configuration. In the Melvin magnetic tube field background there does not exist fuzzy sphere while the fuzzy ring configuration may be formed by the magnetic dielectric effect. The new solution shows that $D_0$ propagating in the D6-branes and magnetic tube field background may expand into a rotating fuzzy ring. We also use the Dirac-Born-Infeld action to construct the ring configuration from the D-branes.Comment: Latex, 15 pages, detailed comments in section 2, typos correcte

Applicability of the orientation average formula in heavy-ion fusion reactions of deformed nuclei

In heavy-ion fusion reactions involving a well deformed nucleus, one often assumes that the orientation of the target nucleus does not change during the reaction. We discuss the accuracy of this procedure by analyzing the excitation function of the fusion cross section and the fusion barrier distribution in the reactions of $^{154}$Sm target with various projectiles ranging from $^{12}$C to $^{40}$Ar. It is shown that the approximation gradually looses its accuracy with increasing charge product of the projectile and target nuclei because of the effects of finite excitation energy of the target nucleus. The relevance of such inaccuracy in analyzing the experimental data is also discussed.Comment: 5 pages and 3 figure

Cell proliferation in bronchial epithelium and submucosal glands of cystic fibrosis patients.

Integrative gene therapy typically requires dividing cells. This requirement has been perceived as an impediment for gene transfer to mature, uninjured airways where proliferation rates are very low. In diseases such as cystic fibrosis (CF) that may be candidates for integrative gene therapy, airway cell turnover is not known but may be increased as a result of chronic inflammation. To determine if cells in airway surface epithelium and submucosal glands of CF patients proliferate at an increased rate, paraffin sections of bronchial segments removed from CF patients (n = 6) at the time of lung transplantation or rapid autopsy and from non-CF patients (n = 4) undergoing lung resection or transplantation were immunostained with PC10, a monoclonal antibody to proliferating cell nuclear antigen (PCNA), a marker of proliferating cells. The PCNA index (percentage of nuclei immunostaining for PCNA) in CF bronchial surface epithelium was 17.0 +/- 4.6% (mean +/- SEM), substantially greater than in non-CF airways (less than 0.2%). Within submucosal glands, PCNA-positive cells were more prevalent in the collecting ducts of CF patients than in those of normal subjects, but only rare mucous or serous cells were PCNA positive. These studies show that airway epithelial cell proliferation rates can be very high in inflamed CF airways. This prevalence of proliferating cells suggests that CF airway epithelium and submucosal gland ducts may be amenable to gene transfer using vectors, such as retroviruses, that require cell replication for stable integrative expression. Further studies are needed to evaluate cell proliferation in CF airways with less extensive airway injury

CP--odd Correlation in the Decay of Neutral Higgs Boson into ZZZZ, W+W−W^+W^-, or ttˉt{\bar t}

We investigate the possibility of detecting CP--odd angular correlations in the various decay modes of the neutral Higgs boson including the modes of a $ZZ$ pair, a $W^+W^-$ pair, or a heavy quark pair. It is a natural way to probe the CP character of the Higgs boson once it is identified. Final state interactions (i.e. the absorptive decay amplitude) is not required in such correlations. As an illustrative example we take the fundamental source of the CP nonconservation to be in the Yukawa couplings of the Higgs boson to the heavy fermions. A similar correlation in the process $e^+e^- \to l^+ l^- H$ is also proposed. Our analysis of these correlations will be useful for experiments in future colliders such as LEP II, SSC, LHC or NLC.Comment: 16 pages, plus 8 postscript graphs not posted befor

Relations between fusion cross sections and average angular momenta

We study the relations between moments of fusion cross sections and averages of angular momentum. The role of the centrifugal barrier and the target deformation in determining the effective barrier radius are clarified. A simple method for extracting average angular momentum from fusion cross sections is demonstrated using numerical examples as well as actual data.Comment: 16 REVTeX pages plus 8 included Postscript figures (uses the epsf macro); submitted to Phys. Rev. C; also available at http://nucth.physics.wisc.edu/preprint