The Big Sibling of AU Mic: A Cold Dust-rich Debris Disk around CP-72 2713 in the β Pic Moving Group

Analyzing Spitzer and Herschel archival measurements we identified a hitherto unknown debris disk around the young K7/M0 star CP-72 2713. The system belongs to the 24Myr old $\beta$ Pic moving group. Our new 1.33mm continuum observation, obtained with the ALMA 7-m array, revealed an extended dust disk with a peak radius of 140au, probably tracing the location of the planetesimal belt in the system. The disk is outstandingly large compared to known spatially resolved debris disks and also to protoplanetary disks around stars of comparable masses. The dynamical excitation of the belt at this radius is found to be reconcilable with planetary stirring, while self-stirring by large planetesimals embedded in the belt can work only if these bodies form very rapidly, e.g. via pebble concentration. By analyzing the spectral energy distribution we derived a characteristic dust temperature of 43K and a fractional luminosity of 1.1$\times$10$^{-3}$. The latter value is prominently high, we know only four other similarly dust-rich Kuiper-belt analogs within 40pc of the Sun

Optical Holonomic Quantum Computer

In this paper the idea of holonomic quantum computation is realized within quantum optics. In a non-linear Kerr medium the degenerate states of laser beams are interpreted as qubits. Displacing devices, squeezing devices and interferometers provide the classical control parameter space where the adiabatic loops are performed. This results into logical gates acting on the states of the combined degenerate subspaces of the lasers, producing any one qubit rotations and interactions between any two qubits. Issues such as universality, complexity and scalability are addressed and several steps are taken towards the physical implementation of this model.Comment: 16 pages, 3 figures, REVTE

Making better use of local data in flood frequency estimation

Flood frequency estimates are an essential part of flood risk management. They are an important ingredient of many important decisions, informing the cost-effectiveness, design and operation of flood defences, flood mapping and planning decisions in flood risk areas. They also inform the National Flood Risk Assessment, the setting of insurance premiums and long-term investment planning. Methods described in the Flood Estimation Handbook (FEH) published in 1999, and many subsequent updates, are considered the industry standard for flood estimation in the UK. They are used extensively by hydrologists from both the public and private sectors. Flood frequency estimates – also known as design flood estimates – are associated with many sources of uncertainty. These hydrological uncertainties often constitute the most uncertain component in any flood study. Uncertainty can lead to difficulty in having confidence in the outputs of studies, whether these are for investment planning, insurance, asset design, development planning or other purposes. As a result, there is considerable benefit to be gained from any reduction in the uncertainty of flood frequency estimation. There are many supplementary sources of information that can help to refine estimates of design floods and potentially reduce uncertainty. Examples include long-term flood history, river level records, photographs of floods and information obtained from field visits. These and similar types of information are defined as ‘local data’. The FEH Local research project aimed to: quantify the uncertainty of design floods estimated from FEH methods develop procedures and guidance for incorporating local and historical data into flood estimation to reduce uncertainties The primary objective of this report is to describe the reviews and research carried out during the FEH Local project. Another output from the project was a document giving guidance to practitioners on how to estimate uncertainty in flood frequency and how to find and incorporate local data. The practitioner guidance, ‘Using Local Data to Reduce Uncertainty in Flood Frequency Estimation’, will be disseminated early in 2017. This report aims to avoid duplication with the practitioner guidance and so is intended mainly for those with an interest in the background to the methods presented in the guidance

Exocometary gas structure, origin and physical properties around β Pictoris through ALMA CO multitransition observations

Recent ALMA observations unveiled the structure of CO gas in the 23 Myr-old $\beta$ Pictoris planetary system, a component that has been discovered in many similarly young debris disks. We here present ALMA CO J=2-1 observations, at an improved spectro-spatial resolution and sensitivity compared to previous CO J=3-2 observations. We find that 1) the CO clump is radially broad, favouring the resonant migration over the giant impact scenario for its dynamical origin, 2) the CO disk is vertically tilted compared to the main dust disk, at an angle consistent with the scattered light warp. We then use position-velocity diagrams to trace Keplerian radii in the orbital plane of the disk. Assuming a perfectly edge-on geometry, this shows a CO scale height increasing with radius as $R^{0.75}$, and an electron density (derived from CO line ratios through NLTE analysis) in agreement with thermodynamical models. Furthermore, we show how observations of optically thin line ratios can solve the primordial versus secondary origin dichotomy in gas-bearing debris disks. As shown for $\beta$ Pictoris, subthermal (NLTE) CO excitation is symptomatic of H$_2$ densities that are insufficient to shield CO from photodissociation over the system's lifetime. This means that replenishment from exocometary volatiles must be taking place, proving the secondary origin of the disk. In this scenario, assuming steady state production/destruction of CO gas, we derive the CO+CO$_2$ ice abundance by mass in $\beta$ Pic's exocomets to be at most $\sim$6%, consistent with comets in our own Solar System and in the coeval HD181327 system.LM acknowledges support by STFC and ESO through graduate studentships and, together with MCW and QK, by the European Union through ERC grant number 279973. Work of OP is funded by the Royal Society Dorothy Hodgkin Fellowship, and AMH gratefully acknowledges support from NSF grant AST-1412647.This is the final version of the article. It first appeared from Oxford University Press via https://doi.org/10.1093/mnras/stw241

Generated heat by different targets irradiated by 660 MeV protons

246-254Calorimetric experiments have been performed to analyze different thick targets of natU, C, Pb material, irradiated by 660 MeV protons at the Phasotron accelerator facility, Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The method of online temperature measurement has been compared with MCNPX 2.7.0 simulation and selected with Ansys Transient Thermal Simulation to compare measured temperature with the simulated one. Thermocouples type T and E have been used as a temperature probe. Many different positions have been measured for each target. Temperature results are following very well the processes inside of the cylinders. Changes of heat deposition caused by drops of the proton beam intensity are displayed very well as a jagged line shown in almost every chart. Accurate temperature changing measurement is a very modest variation of how to observe inner macroscopic behavior online

Calixpyrroles, calixpyridinopyrroles and calixpyridines

The present invention provides calixpyrrole, calixpyridinopyrrole, and calixpyridine macrocycles, having 4, 5, 6, 7, or 8 heterocyclic rings, as well as syntheses, derivatives, conjugates, multimers, and solid supports thereof. Such macrocycles have proved to be effective and selective ion- and neutral molecule-binding agents forming supramolecular ensembles, and ion- and neutral molecule-separation agents. The macrocycles are fully meso-non-hydrogen-substituted porphyrinogens, a few molecules of which were previously known but not recognized as possessing anion- or molecule-binding properties. The binding mode is noncovalent, primarily that of hydrogen-bonding, thereby providing a new mode for liquid chromatography, that of Hydrogen Bonding Liquid Chromatography. Further useful applications of the macrocycles provided herein include environmental remediation by removal of undesired ions or neutral molecules, and removal of phosphate for kidney dialysis.Board of Regents, University of Texas Syste

Analytic representations based on SU(1,1) coherent states and their applications

We consider two analytic representations of the SU(1,1) Lie group: the representation in the unit disk based on the SU(1,1) Perelomov coherent states and the Barut-Girardello representation based on the eigenstates of the SU(1,1) lowering generator. We show that these representations are related through a Laplace transform. A ``weak'' resolution of the identity in terms of the Perelomov SU(1,1) coherent states is presented which is valid even when the Bargmann index $k$ is smaller than one half. Various applications of these results in the context of the two-photon realization of SU(1,1) in quantum optics are also discussed.Comment: LaTeX, 15 pages, no figures, to appear in J. Phys. A. More information on http://www.technion.ac.il/~brif/science.htm

Circumstellar discs: What will be next?

This prospective chapter gives our view on the evolution of the study of circumstellar discs within the next 20 years from both observational and theoretical sides. We first present the expected improvements in our knowledge of protoplanetary discs as for their masses, sizes, chemistry, the presence of planets as well as the evolutionary processes shaping these discs. We then explore the older debris disc stage and explain what will be learnt concerning their birth, the intrinsic links between these discs and planets, the hot dust and the gas detected around main sequence stars as well as discs around white dwarfs.Comment: invited review; comments welcome (32 pages