Imprints of the jittering jets explosion mechanism in the morphology of the supernova remnant SNR~0540-69.3

I identify a point-symmetric structure in recently published VLT/MUSE velocity maps of different elements in a plane along the line of sight at the center of the supernova remnant SNR~0540-69.3, and argue that jittering jets that exploded this core collapse supernova shaped this point-symmetric structure. The four pairs of two opposite clumps that compose this point symmetric structure suggest that two to four pairs of jittering jets shaped the inner ejecta in this plane. In addition, intensity images of several spectral lines reveal a faint strip (the main jet-axis) that is part of this plane of jittering jets and its similarity to morphological features in a few other SNRs and in some planetary nebulae further suggests shaping by jets. My interpretation implies that in addition to instabilities, jets also mix elements in the ejecta of core collapse supernovae. Based on the point-symmetric structure and under the assumption that jittering jets exploded this supernova, I estimate the component of the neutron star natal kick velocity on the plane of the sky to be $\simeq 235 \km\s^{-1}$, and at an angle of $\simeq 47^\circ$ to the direction of the main jet-axis. I analyse this natal kick direction together with other 12 SNRs in the frame of the jittering jets explosion mechanism.

Спектроскопическое исследование кристаллов KY-=SUB=-3-=/SUB=-F-=SUB=-10-=/SUB=-, активированных празеодимом

We report on the high-resolution Fourier spectroscopy study of KY3F10:Pr3+ crystals. The analysis of the transmission and luminescence spectra allowed us to refine and supplement the information on the crystal-field levels of the Pr3+ ion. The value of the hyperfine splitting of the ground state of Pr3+ in the KY3F10 cubic matrix is estimated. The observed shape of the spectral lines indicates the presence of defects in the sample under study.

Optimal Behavior of Spectral Line Analysis Through Fine Identification of Heavy Metal Lines in Crude Oil Using LIPS-Technique

Assessment of the quality of minerals, especially heavy ones, in crude oil by identifying spectral lines is very important to determine the quality and specifications of crude oil and the following treatments in production of the lines. In this study heavy metals lines (HMs) found in crude oil extracted from Iraq south field were identified that are unique spectral lines by using the laser-induced plasma spectroscopy (LIPS – mechanism), which were analyzed later by spectrometer based on the principle of finger print. The optimum spectrum (analytical lines) of metals emitted from the crude oil plasma in air were selected and determined. By determining the optimization behavior for evaluation procedure, the important condition was laser spot number (scan area). Comparison was performed between the fundamental wavelength and harmonic generation (HG) used in the laser beam to determine the optimum spectrum and optical insulator to cover the selected sample at atmospheric air pressure and room temperature. The results obtained from the actual raw spectrum were determined to represent the emission lines without the influence of foreign light (no noise) using the optical isolator, and unique new analytical lines were identified when increasing the number of lasers points up to 5 points, and a balanced spectrum was determined with good absorption when using a basic wavelength of 1064 nm. Difficulties were presented due to the characteristics of the crude oil as organic liquid case. The optimum results obtained indicated that the LIPS technique is effective and a control technique to well identify the spectrum lines of the heavy metals (HMs) presented in the crude oil.

Unexpected discovery of estrone in the rotational spectrum of estradiol: A systematic investigation of a CP-FTMW spectrum

We report the reinvestigation of the high-resolution rotational spectrum of estradiol. After removing the known spectral lines corresponding to three conformers of estradiol identified in the gas phase before, a...

Hydrothermal Synthesis of Ag Thin Films and Their SERS Application

In this article, a facile, one-step method for the formation of silver thin-film nanostructures on the surface of Al2O3 substrates using the hydrothermal method is proposed. The dependence of the SERS effect intensity of the formed films during the detection of methylene blue (MB) low concentrations on the synthesis conditions, additional temperature treatment, and laser radiation wavelength (532 and 780 nm) in comparison with similar dye films on commercial SERS substrates is shown. The detection limit of the analyte used for the indicated lasers is estimated. The effect of the synthesis temperature on the particle size, crystal structure, and microstructure features of the obtained thin films based on silver nanoparticles is demonstrated. Using spreading resistance microscopy, the interface between the substrate and Ag particles is studied, and the dependence of the size of the corresponding gap between them and the nature of microstructural defects on the parameters of hydrothermal treatment of reaction systems in the presence of Al2O3 substrates is shown. As a result of the study, the factors associated with the properties of the obtained SERS substrates and the parameters of recording the spectra, which affect the amplification factor of the spectral lines intensity of the analyte, are revealed.

Influence of the Distance between Focusing Lens and Target Surface on the Characteristics of Laser-excited Lead Plasma

The present work investigated the effect of distance from target surface on the parameters of lead plasma excited by 1064nm Q-switched Nd:YAG laser. The excitation was conducted in air, at atmospheric pressure, with pulse length of 5 ns, and at different pulse laser energies. Electron temperature was calculated by Boltzmann plot method based on the PbI emission spectral lines (369.03 nm, 416.98 nm, 523.48, and 561.94 nm). The PbI lines were recorded at different distances from the target surface at laser pulse energies of 260 and 280 mJ. The emission intensity of plasma increased with increasing the lens-to-target distance. The results also detected an increase in electron temperature with increasing the distance between the focal lens and the surface of the target in all laser energies under study. In addition, the electron number density was determined by using the Stark broadening method. The data illustrated that the electron number density was increased with increasing the distance from target surface, reaching the maximum at a distance of 11 cm for all pulse laser energy levels under study.

Geomagnetic Pulsations, Blackout and Low-Latitude Aurorae Associated with Power Magnetic Storm

The research analyzed the regularities of the dynamics of geomagnetic pulsation regimes in the frequency range 0.002–5 Hz, the generation of which reflects the interaction with the Earth's magnetosphere of the solar filament ejected by a powerful solar flare of 3B. We compared the dynamics of the change in the types and modes of geomagnetic pulsations with the dynamics of the atmosphere glow in two spectral lines and the total ionospheric absorption of radio waves. The study developed a possible model of the observed phenomenon.

Using on-stream X-ray fluorescence analysis to determine the chemical composition of drill cuttings

Background. The authors investigate the problems arising from the lack of information on the chemical composition of the drilled rocks during the construction of a well. Aim. The aim of this study is to determine the possibilities and efficient application of the streaming XRF method for determining the elemental composition of unwashed drill cuttings. The contribution of the paper lies in the lack of experience in the world practice of using streaming XRF analyzers. Materials and methods. Furthermore, the authors evaluate the possibility to use the streaming XRF method for analyzing the chemical composition of drill cuttings for the development of the oil industry. At the same time, the application of the proposed method is justified. The basis of this study are the results of the application of the streaming XRF method using the CON-X 02 streaming spectrometer for analyzing the chemical composition of drill cuttings not washed from drilling mud. This project has been implemented according the technological project between Gazpromneft — NNGGF LLC in cooperation with Nosov Magnitogorsk State Technical University and Gazpromneft — STC LLC. Result. The article presents the results of determined main elements of the composition of drill cuttings. The authors have carried out the analysis of changes in the intensity of the characteristic lines of the main components from the sampling depth. Simultaneously, the authors show the possibilities to derive correlation curves for various elements characteristic of certain rocks in the geological section of a particular field. Moreover, the study reveals the identification and characteristics of geochemical signs of specific target layers. Conclusions. Based on the results of the study, authors may conclude that to obtain the correct results on the intensity of spectral lines of various chemical elements during streaming XRF analysis, there is no need to flush the cuttings from the drilling fluid. Finally, it is possible to qualitatively control the main elements of the composition of the drill cuttings.

Promise of Persistent Multi-Messenger Astronomy with the Blazar OJ 287

Successful observations of the seven predicted bremsstrahlung flares from the unique bright blazar OJ 287 firmly point to the presence of a nanohertz gravitational wave (GW) emitting supermassive black hole (SMBH) binary central engine. We present arguments for the continued monitoring of the source in several electromagnetic windows to firmly establish various details of the SMBH binary central engine description for OJ 287. In this article, we explore what more can be known about this system, particularly with regard to accretion and outflows from its two accretion disks. We mainly concentrate on the expected impact of the secondary black hole on the disk of the primary on 3 December 2021 and the resulting electromagnetic signals in the following years. We also predict the times of exceptional fades, and outline their usefulness in the study of the host galaxy. A spectral survey has been carried out, and spectral lines from the secondary were searched for but were not found. The jet of the secondary has been studied and proposals to discover it in future VLBI observations are mentioned. In conclusion, the binary black hole model explains a large number of observations of different kinds in OJ 287. Carefully timed future observations will be able to provide further details of its central engine. Such multi-wavelength and multidisciplinary efforts will be required to pursue multi-messenger nanohertz GW astronomy with OJ 287 in the coming decades.