A population study of gaseous exoplanets

We present here the analysis of 30 gaseous extrasolar planets, with temperatures between 600 and 2400 K and radii between 0.35 and 1.9 $R_\mathrm{Jup}$. The quality of the HST/WFC3 spatially scanned data combined with our specialized analysis tools allow us to study the largest and most self-consistent sample of exoplanetary transmission spectra to date and examine the collective behavior of warm and hot gaseous planets rather than isolated case-studies. We define a new metric, the Atmospheric Detectability Index (ADI) to evaluate the statistical significance of an atmospheric detection and find statistically significant atmospheres around 16 planets out of the 30 analysed. For most of the Jupiters in our sample, we find the detectability of their atmospheres to be dependent on the planetary radius but not on the planetary mass. This indicates that planetary gravity plays a secondary role in the state of gaseous planetary atmospheres. We detect the presence of water vapour in all of the statistically detectable atmospheres, and we cannot rule out its presence in the atmospheres of the others. In addition, TiO and/or VO signatures are detected with 4$\sigma$ confidence in WASP-76 b, and they are most likely present in WASP-121 b. We find no correlation between expected signal-to-noise and atmospheric detectability for most targets. This has important implications for future large-scale surveys.Comment: 14 pages, 12 figures, 3 tables, published in A

Interaction between superconducting vortices and Bloch wall in ferrite garnet film

Interaction between a Bloch wall in a ferrite-garnet film and a vortex in a superconductor is analyzed in the London approximation. Equilibrium distribution of vortices formed around the Bloch wall is calculated. The results agree quantitatively with magneto-optical experiment where an in-plane magnetized ferrite-garnet film placed on top of NbSe2 superconductor allows observation of individual vortices. In particular, our model can reproduce a counter-intuitive attraction observed between vortices and a Bloch wall having the opposite polarity. It is explained by magnetic charges appearing due to discontinuity of the in-plane magnetization across the wall.Comment: 4 pages, 5 figure

Reduction of the content of harmful impurities during technical silicon melting using the filtering method

The article discusses the filtration method of cleaning silicon, the possibility of mechanical separation of inclusions, the effect of capillary phenomena, the wettability of the filter material on the efficiency of cleaning silicon from impurities. There are also considered the advantages of bulk granular filters which consist of the lumpy or granulated elements. There are described the methods of obtaining filtering elements, the functions executed by the filters depending on their type. There are presented the analysis results obtained in filter refinement of silicon which show the impact of different filters materials on the content of impurities

Oxygen activity changing when simulating silicon filtering process

In the article there is considered the efficiency of using filters for the refinement of metal melts, the use of filters in metallurgical practice and research of the inoculating mechanism of filter refinement of a metal melt from the dissolved impurities. In the inoculating mechanism the surface of the filter serves as a substrate for separation on it the nonmetallic phase directly from the melt, passing the stage of its separation into an isolated particle. This is proved experimentally, by monitoring the change of the deleted impurity activity by the EMF (electromotive force) method

Oxygen activity changing when simulating silicon filtering process

In the article there is considered the efficiency of using filters for the refinement of metal melts, the use of filters in metallurgical practice and research of the inoculating mechanism of filter refinement of a metal melt from the dissolved impurities. In the inoculating mechanism the surface of the filter serves as a substrate for separation on it the nonmetallic phase directly from the melt, passing the stage of its separation into an isolated particle. This is proved experimentally, by monitoring the change of the deleted impurity activity by the EMF (electromotive force) method

The history of Drosophila studies: steps in the development of genetics

Experimental genetic studies of Drosophila were initiated by T.H. Morgan in 1910, when he discovered the sex-linked white-eyed mutation, white. This discovery commenced the transformation of Mendel’s “hereditary factors” to more specific but no less enigmatic W.L. Johanssen’s “genes”. Owing to Drosophila’s biologic features, it became a universal eukaryotic model for genetic, embryological, morphological, physiological, molecular, and cellular studies. Actually, the history of discoveries done on Drosophila species reflects the course of genetics development. That was Drosophila studies to lay foundation for genetic notions of the nature of genes, genetic linkage, mitotic and meiotic chromosome segregation, mechanisms governing mutagenesis and recombination, genetic instability, mobile genetic elements, regularities and genetics of individual development, and microevolutionary processes in populations. The paper considers steps and milestones of genetics development by examples of the American and Russian genetic schools. The American genetics was characterized by “reductionism”, whereas the Russian genetics was inclined to “cosmism”, where emphasis was placed on the understanding of macroevolutionary processes. Drosophila has become a test ground to try new genetic methods, and its studies contribute much to biomedical science. The paper outlines several top priority fields in modern Drosophila studies

A weak spectral signature of water vapour in the atmosphere of HD 179949 b at high spectral resolution in the L band

High-resolution spectroscopy (R≤20,000) is currently the only known method to constrain the orbital solution and atmospheric properties of non-transiting hot Jupiters. It does so by resolving the spectral features of the planet into a forest of spectral lines and directly observing its Doppler shift while orbiting the host star. In this study, we analyse VLT/CRIRES (R=100,000) L-band observations of the non-transiting giant planet HD 179949 b centred around 3.5μm. We observe a weak (3.0σ, or S/N=4.8) spectral signature of H2O in absorption contained within the radial velocity of the planet at superior-conjunction, with a mild dependence on the choice of line list used for the modelling. Combining this data with previous observations in the K band, we measure a detection significance of 8.4σ for an atmosphere that is most consistent with a shallow lapse-rate, solar C/O ratio, and with CO and H2O being the only major sources of opacity in this wavelength range. As the two sets of data were taken 3 yr apart, this points to the absence of strong radial-velocity anomalies due, e.g. to variability in atmospheric circulation. We measure a projected orbital velocity for the planet of K_P=(145.2±2.0) km/s (1σ ) and improve the error bars on this parameter by ∼70 per cent. However, we only marginally tighten constraints on orbital inclination (66.2+3.7−3.1 deg) and planet mass (0.963+0.036−0.031 Jupiter masses), due to the dominant uncertainties of stellar mass and semi-major axis. Follow ups of radial-velocity planets are thus crucial to fully enable their accurate characterization via high-resolution spectroscopy

Optical frequency comb Fourier transform spectroscopy of formaldehyde in the 1250 to 1390 cm−1 range: Experimental line list and improved MARVEL analysis

We use optical frequency comb Fourier transform spectroscopy to record high-resolution, low-pressure, room-temperature spectra of formaldehyde (H212C16O) in the range of 1250 to 1390 cm−1. Through line-by-line fitting, we retrieve line positions and intensities of 747 rovibrational transitions: 558 from the ν6 band, 129 from the ν4 band, and 14 from the ν3 band, as well as 46 from four different hot bands. We incorporate the accurate and precise line positions (0.4 MHz median uncertainty) into the MARVEL (measured active vibration-rotation energy levels) analysis of the H2CO spectrum. This increases the number of MARVEL-predicted energy levels by 82 and of rovibrational transitions by 5382, and substantially reduces uncertainties of MARVEL-derived H2CO energy levels over a large range: from pure rotational levels below 200 cm−1 up to multiply excited vibrational levels at 6000 cm−1. This work is an important step toward filling the gaps in formaldehyde data in the HITRAN database

Algebraic-matrix calculation of vibrational levels of triatomic molecules

We introduce an accurate and efficient algebraic technique for the computation of the vibrational spectra of triatomic molecules, of both linear and bent equilibrium geometry. The full three-dimensional potential energy surface (PES), which can be based on entirely {\it ab initio} data, is parameterized as a product Morse-cosine expansion, expressed in bond-angle internal coordinates, and includes explicit interactions among the local modes. We describe the stretching degrees of freedom in the framework of a Morse-type expansion on a suitable algebraic basis, which provides exact analytical expressions for the elements of a sparse Hamiltonian matrix. Likewise, we use a cosine power expansion on a spherical harmonics basis for the bending degree of freedom. The resulting matrix representation in the product space is very sparse and vibrational levels and eigenfunctions can be obtained by efficient diagonalization techniques. We apply this method to carbonyl sulfide OCS, hydrogen cyanide HCN, water H$_2$O, and nitrogen dioxide NO$_2$. When we base our calculations on high-quality PESs tuned to the experimental data, the computed spectra are in very good agreement with the observed band origins.Comment: 11 pages, 2 figures, containg additional supporting information in epaps.ps (results in tables, which are useful but not too important for the paper