The Peculiar Atmospheric Chemistry of KELT-9b

The atmospheric temperatures of the ultra-hot Jupiter KELT-9b straddle the transition between gas giants and stars, and therefore between two traditionally distinct regimes of atmospheric chemistry. Previous theoretical studies assume the atmosphere of KELT-9b to be in chemical equilibrium. Despite the high ultraviolet flux from KELT-9, we show using photochemical kinetics calculations that the observable atmosphere of KELT-9b is predicted to be close to chemical equilibrium, which greatly simplifies any theoretical interpretation of its spectra. It also makes the atmosphere of KELT-9b, which is expected to be cloudfree, a tightly constrained chemical system that lends itself to a clean set of theoretical predictions. Due to the lower pressures probed in transmission (compared to emission) spectroscopy, we predict the abundance of water to vary by several orders of magnitude across the atmospheric limb depending on temperature, which makes water a sensitive thermometer. Carbon monoxide is predicted to be the dominant molecule under a wide range of scenarios, rendering it a robust diagnostic of the metallicity when analyzed in tandem with water. All of the other usual suspects (acetylene, ammonia, carbon dioxide, hydrogen cyanide, methane) are predicted to be subdominant at solar metallicity, while atomic oxygen, iron and magnesium are predicted to have relative abundances as high as 1 part in 10,000. Neutral atomic iron is predicted to be seen through a forest of optical and near-infrared lines, which makes KELT-9b suitable for high-resolution ground-based spectroscopy with HARPS-N or CARMENES. We summarize future observational prospects of characterizing the atmosphere of KELT-9b.Comment: Accepted by ApJ. 9 pages, 6 figures. Corrected minor errors in Figures 1a and 1b (some line styles were switched by accident), text and conclusions unchanged, these minor changes will be updated in final ApJ proo

Rare Decays with a Light CP-Odd Higgs Boson in the NMSSM

We have previously proposed a light pseudoscalar Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM), the A_1^0, as a candidate to explain the HyperCP observations in Sigma^+ -> p mu^+ mu^-. In this paper we calculate the rates for several other rare decay modes that can help confirm or refute this hypothesis. The first modes we evaluate are K_L -> pi pi A_1^0, which are interesting because they are under study by the KTeV Collaboration. We next turn to eta -> pi pi A_1^0, which are interesting because they are independent of the details of the flavor-changing sector of the NMSSM and may be accessible at DAPhNE. For completeness, we also evaluate Omega^- -> Xi^- A_1^0.Comment: 17 pages, 11 figure

Nanopore‐Based, Rapid Characterization of Individual Amyloid Particles in Solution: Concepts, Challenges, and Prospects

Aggregates of misfolded proteins are associated with several devastating neurodegenerative diseases. These so‐called amyloids are therefore explored as biomarkers for the diagnosis of dementia and other disorders, as well as for monitoring disease progression and assessment of the efficacy of therapeutic interventions. Quantification and characterization of amyloids as biomarkers is particularly demanding because the same amyloid‐forming protein can exist in different states of assembly, ranging from nanometer‐sized monomers to micrometer‐long fibrils that interchange dynamically both in vivo and in samples from body fluids ex vivo. Soluble oligomeric amyloid aggregates, in particular, are associated with neurotoxic effects, and their molecular organization, size, and shape appear to determine their toxicity. This concept article proposes that the emerging field of nanopore‐based analytics on a single molecule and single aggregate level holds the potential to account for the heterogeneity of amyloid samples and to characterize these particles—rapidly, label‐free, and in aqueous solution—with regard to their size, shape, and abundance. The article describes the concept of nanopore‐based resistive pulse sensing, reviews previous work in amyloid analysis, and discusses limitations and challenges that will need to be overcome to realize the full potential of amyloid characterization on a single‐particle level.Information about amyloid aggregation states is critical to understanding the pathological progression of many neurodegenerative diseases. Resistive pulse‐based nanopore sensing is a unique single‐molecule approach to studying these aggregation states because it can determine information about individual amyloids, oligomeric species, or fibrils in an aqueous solution without fluorescent labels or chemical modifications.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146577/1/smll201802412_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146577/2/smll201802412.pd

Results from the first burst hardware injections performed on GEO600

GEO 600 is a 600 m arm-length, laser interferometric gravitational wave detector, located about 25 km from Hannover, Germany. Starting in November 2003, GEO 600 took part in a coincident data taking period with other detectors around the world. During this time, GEO 600 acquired three weeks of 'science quality' data. These data are currently being processed to search for gravitational wave signatures. One such search is that for burst gravitational waves. To investigate the performance of any burst-search codes used to analyse the data, burst-like signals were injected into the detector after the data taking run; this was done by differentially driving the end mirrors of the interferometer. In this paper, we report on how the first burst hardware injections were performed on GEO 600, the type of signals injected and the analysis of the data from the period of injections. Results from the analysis are also presented and discussed

Reply to Letter to the Editor : Is HPV-18 present in human breast cancer cell lines

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A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b

Context: KELT-9 b exemplifies a newly emerging class of short-period gaseous exoplanets that tend to orbit hot, early type stars - termed ultra-hot Jupiters. The severe stellar irradiation heats their atmospheres to temperatures of $\sim 4,000$ K, similar to the photospheres of dwarf stars. Due to the absence of aerosols and complex molecular chemistry at such temperatures, these planets offer the potential of detailed chemical characterisation through transit and day-side spectroscopy. Studies of their chemical inventories may provide crucial constraints on their formation process and evolution history. Aims: To search the optical transmission spectrum of KELT-9 b for absorption lines by metals using the cross-correlation technique. Methods: We analyse 2 transits observed with the HARPS-N spectrograph. We use an isothermal equilibrium chemistry model to predict the transmission spectrum for each of the neutral and singly-ionized atoms with atomic numbers between 3 and 78. Of these, we identify the elements that are expected to have spectral lines in the visible wavelength range and use those as cross-correlation templates. Results: We detect absorption of Na I, Cr II, Sc II and Y II, and confirm previous detections of Mg I, Fe I, Fe II and Ti II. In addition, we find evidence of Ca I, Cr I, Co I, and Sr II that will require further observations to verify. The detected absorption lines are significantly deeper than model predictions, suggesting that material is transported to higher altitudes where the density is enhanced compared to a hydrostatic profile. There appears to be no significant blue-shift of the absorption spectrum due to a net day-to-night side wind. In particular, the strong Fe II feature is shifted by $0.18 \pm 0.27$ km~s$^{-1}$, consistent with zero. Using the orbital velocity of the planet we revise the steller and planetary masses and radii.Comment: Submitted to Astronomy and Astrophysics on January 18, 2019. Accepted on May 3, 2019. 26 pages, 11 figure

Null-stream veto for two co-located detectors: Implementation issues

Time-series data from multiple gravitational wave (GW) detectors can be linearly combined to form a null-stream, in which all GW information will be cancelled out. This null-stream can be used to distinguish between actual GW triggers and spurious noise transients in a search for GW bursts using a network of detectors. The biggest source of error in the null-stream analysis comes from the fact that the detector data are not perfectly calibrated. In this paper, we present an implementation of the null-stream veto in the simplest network of two co-located detectors. The detectors are assumed to have calibration uncertainties and correlated noise components. We estimate the effect of calibration uncertainties in the null-stream veto analysis and propose a new formulation to overcome this. This new formulation is demonstrated by doing software injections in Gaussian noise.Comment: Minor changes; To appear in Class. Quantum Grav. (Proc. GWDAW10