The thermal and kinematic Sunyaev-Zel'dovich effects revisited

This paper shows that a simple convolution integral expression based on the mean value of the isotropic frequency distribution corresponding to photon scattering off electrons leads to useful analytical expressions describing the thermal Sunyaev-Zel'dovich effect. The approach, to first order in the Compton parameter is able to reproduce the Kompaneets equation describing the effect. Second order effects in the parameter $z=\frac{kT_{e}}{mc^{2}}$ induce a slight increase in the crossover frequency.Comment: 7 pages, 2 figure

The Atmospheric Chemistry Suite (ACS) of Three Spectrometers for the ExoMars 2016 Trace Gas Orbiter

The Atmospheric Chemistry Suite (ACS) package is an element of the Russian contribution to the ESA-Roscosmos ExoMars 2016 Trace Gas Orbiter (TGO) mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. This ensemble of spectrometers has been designed and developed in response to the Trace Gas Orbiter mission objectives that specifically address the requirement of high sensitivity instruments to enable the unambiguous detection of trace gases of potential geophysical or biological interest. For this reason, ACS embarks a set of instruments achieving simultaneously very high accuracy (ppt level), very high resolving power (>10,000) and large spectral coverage (0.7 to 17 μm—the visible to thermal infrared range). The near-infrared (NIR) channel is a versatile spectrometer covering the 0.7–1.6 μm spectral range with a resolving power of ∼20,000. NIR employs the combination of an echelle grating with an AOTF (Acousto-Optical Tunable Filter) as diffraction order selector. This channel will be mainly operated in solar occultation and nadir, and can also perform limb observations. The scientific goals of NIR are the measurements of water vapor, aerosols, and dayside or night side airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the 2.2–4.4 μm range. MIR achieves a resolving power of >50,000. It has been designed to accomplish the most sensitive measurements ever of the trace gases present in the Martian atmosphere. The thermal-infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer encompassing the spectral range of 1.7–17 μm with apodized resolution varying from 0.2 to 1.3 cm−1. TIRVIM is primarily dedicated to profiling temperature from the surface up to ∼60 km and to monitor aerosol abundance in nadir. TIRVIM also has a limb and solar occultation capability. The technical concept of the instrument, its accommodation on the spacecraft, the optical designs as well as some of the calibrations, and the expected performances for its three channels are described

Detector Description and Performance for the First Coincidence Observations between LIGO and GEO

For 17 days in August and September 2002, the LIGO and GEO interferometer gravitational wave detectors were operated in coincidence to produce their first data for scientific analysis. Although the detectors were still far from their design sensitivity levels, the data can be used to place better upper limits on the flux of gravitational waves incident on the earth than previous direct measurements. This paper describes the instruments and the data in some detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial change

ПЕРВЫЕ ШАГИ В НАУЧНО-ПОПУЛЯРНОМ КОНТЕНТЕ: МИНИ-ПРИЛОЖЕНИЕ «КОПЕРНИК» КАК СРЕДСТВО РАЗВИТИЯ СТУДЕНЧЕСКИХ НАУЧНЫХ ОБЩЕСТВ

Students' science is one of the most important factor of progress in the field of the formation of scientific personnel. Young scientists are trying to start research from the university bench, but they face insurmountable difficulties, lack of information and experience. As a solution to the problem, we propose the project “Kopernik” by name, a multimedia platform for ensuring the interaction of students' scientific societies and undergraduate students.Студенческая наука - один из двигателей прогресса в области формирования научных кадров. Молодые ученые уже с университетской скамьи пробуют проводить исследования, но сталкиваются с непреодолимыми сложностями, недостатком информации и опыта. В качестве решения проблемы мы предлагаем проект «Коперник» - мультимедийную площадку для обеспечения взаимодействия студенческих научных обществ, абитуриентов и студентов младших курсов

Determining the small spacecraft Aist-2D attitude motion by measurements of the equipment KMU-1

Abstract: The paper presents the results of reconstruction of the spacecraft Aist-2D attitude motion in summer 2016. The reconstruction is based on processing the measurements of two vectors: the spacecraft angular rate and the strength of the Earth magnetic field. The processing technique uses kinematical equations of the attitude motion of a rigid body. In its framework, the measurement data of both types, collected on a time interval, are processed jointly. The angular rate data are interpolated by piecewise linear functions and those functions are substituted in kinematical equations for components of the quaternion, which defines a transformation of the spacecraft coupled coordinate system to the inertial one. The equations obtained present the kinematical model of a spacecraft attitude motion. The solution of the equations, which approximates the real motion, is found by the least squares method from the condition of the best agreement between measured and calculated data of the magnetic strength. The technique allows reconstructing the attitude motion on time intervals more than 10 hours.Note: Research direction:Theoretical and applied problems of mechanic

Uncontrolled attitude motion of the prototype of the small spacecraft Aist

Abstract: We present the results of reconstruction of the uncontrolled attitude motion of the prototype of the small spacecraft Aist during its flight at the beginning of 2014. The reconstruction was realized by processing onboard measurements of the Earth magnetic field. The measurement data were accumulated in time segments, which had length about 100 min. The measurement data on each such segment were processed sim-ultaneously by means of the least squares method and integration of the spacecraft attitude motion equations. The estimates of the mathematical model parameters and initial conditions of the attitude motion were obtained as a result of such processing. The results of processing some segments above made clear the attitude motion of the spacecraft.Note: Research direction:Theoretical and applied problems of mechanic

Determination of the spacecraft Aist attitude motion on measurements of the Earth magnetic field

Abstract: We present the results of reconstruction of the uncontrolled attitude motion of the small spacecraft Aist during its flight in May 2013. The reconstruction was realized by processing onboard measurements of the Earth magnetic field strength. The measurement data were accumulated in time segments, which had length about 100 min. The measurement data on each such segment were processed simultaneously by means of the least squares method and integration of the spacecraft attitude motion equations. The estimates of the mathematical model parameters and initial conditions of the attitude motion were obtained as a result of such processing. The results of processing some segments above made clear the attitude motion of the spacecraft.Note: Research direction:Theoretical and applied problems of mechanic

Spectroscopic Redshift Determination for a Sample of Distant Quasars Detected by the SRG Observatory Based on RTT-150 Observations. II

Abstract: Results of the spectroscopic observations at the 1.5-m Russian–Turkish telescope for another group of 12 X-ray sources discovered by the eROSITA telescope onboard the SRG space observatory and identified by the SRGz machine learning system as candidates for distant X-ray quasars are presented. Ten objects have been confirmed as quasars at redshifts z=2.6{-}3.2 and two sources have turned out to be active galactic nuclei (AGNs) at z=0.42 and 1.02