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<jats:title>Abstract</jats:title> <jats:p>A sample of 392 low-mass hierarchical triple stellar systems within 100 pc resolved by Gaia as distinct sources is defined. Owing to the uniform selection, the sample is ideally suited to study unbiased statistics of wide triples. The median projected separations in their inner and outer pairs are 151 and 2569 au, respectively, and the median separation ratio is close to 15. Some triples appear in nonhierarchical configurations, and many are just above the dynamical stability limit. Internal motions in these systems are known with sufficient accuracy to determine the orbital motion sense of the outer and inner pairs and to reconstruct the eccentricity distributions. The mean inner and outer eccentricities are 0.66 ± 0.02 and 0.54 ± 0.02, respectively; the less eccentric outer orbits are explained by dynamical stability. The motion sense of the inner and outer pairs is almost uncorrelated, implying a mean mutual inclination of 83.°1 ± 4.°5. The median mass of the most massive component is 0.71 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, and the median system mass is 1.53 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>. In a 0.69 fraction of the sample the primary belongs to the inner binary, while in the remaining systems it is the tertiary. A 0.21 fraction of the inner subsystems are twins with mass ratios &gt;0.95. The median outer mass ratio is 0.41; it decreases mildly with increasing outer separation. Presumably, these wide hierarchies were formed by collapse and fragmentation of isolated cores in low-density environments and represent a small fraction of initial systems that avoided dynamical decay. Wide pre-main-sequence multiples in Taurus could be their progenitors.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The paper considers a dynamo generated by a shallow fluid layer in a celestial body (planet or star). This dynamo is based on the extra invariant for interacting magnetic Rossby waves.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The first set of theoretical rotational cross sections for propylene oxide (CH<jats:sub>3</jats:sub>CHCH<jats:sub>2</jats:sub>O) colliding with cold He atoms has been obtained at the full quantum level using a high-accuracy potential energy surface. By scaling the collision reduced mass, rotational rate coefficients for collisions with para-H<jats:sub>2</jats:sub> are deduced in the temperature range 5–30 K. These collisional coefficients are combined with radiative data in a non-LTE radiative transfer model in order to reproduce observations of propylene oxide made toward the Sagittarius B2(N) molecular cloud with the Green Bank and Parkes radio telescopes. The three detected absorption lines are found to probe the cold (∼10 K) and translucent (<jats:italic>n</jats:italic> <jats:sub>H</jats:sub> ∼ 2000 cm<jats:sup>−3</jats:sup>) gas in the outer edges of the extended Sgr B2(N) envelope. The derived column density for propylene oxide is <jats:italic>N</jats:italic> <jats:sub>tot</jats:sub> ∼ 3 × 10<jats:sup>12</jats:sup> cm<jats:sup>−2</jats:sup>, corresponding to a fractional abundance relative to total hydrogen of ∼2.5 × 10<jats:sup>−11</jats:sup>. The present results are expected to help our understanding of the chemistry of propylene oxide, including a potential enantiomeric excess, in the cold interstellar medium.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>This paper investigates the impact of radiative and mechanical feedback from O-type stars on their parent molecular clouds and the triggering of formation of a future generation of stars. We study the infrared bubble S111 created by the embedded massive stellar cluster G316.80–0.05. A significant fraction of gas in shells created due to the compression of the ambient medium by expanding bubbles is photodissociated by the stellar radiation. The kinematics of the shells are thus best studied using spectroscopic observations of singly ionized carbon, the most dominant species. We have used velocity-resolved maps of the <jats:sup>2</jats:sup>P<jats:sub>3/2</jats:sub> → <jats:sup>2</jats:sup>P<jats:sub>1/2</jats:sub> transition of [C <jats:sc>ii</jats:sc>] at 158 <jats:italic>μ</jats:italic>m, the <jats:italic>J</jats:italic> = 2–1 transition of <jats:sup>13</jats:sup>CO and C<jats:sup>18</jats:sup>O, and the <jats:italic>J</jats:italic> = 1–0 transition of HCO<jats:sup>+</jats:sup> to study the rim of the bubble S111 that partly coincides with the southern part of the infrared dark ridge G316.75. The [C <jats:sc>ii</jats:sc>] spectra conclusively show evidence of a shell expanding with a moderate velocity of ∼7 km s<jats:sup>−1</jats:sup>, which amounts to a kinetic energy that is ∼0.5–40 times the thermal energy of the H <jats:sc>ii</jats:sc> region. The pressure causing the expansion of the H <jats:sc>ii</jats:sc> region arises mainly from hydrogen ionization and dust-processed radiation. Among the far-infrared sources located in compressed shells, we find the core G316.7799–0.0942 to show broad spectral features consistent with outflow activity and conclude that it is a site of active star formation. Based on the age of the H <jats:sc>ii</jats:sc> region we conclude that this expanding H <jats:sc>ii</jats:sc> region is responsible for triggering the current star formation activity in the region.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Focusing on the electron and positron spectrum measured with the Calorimetric Electron Telescope (CALET), which shows characteristic structures, we calculate the flux contributions of cosmic rays that have escaped from randomly appearing supernova remnants. We adopt a Monte Carlo method to take into account the stochastic nature of the appearance of nearby sources. We find that without a complicated energy dependence of the diffusion coefficient, simple power-law diffusion coefficients can produce spectra similar to the CALET spectrum, even with a dispersion in the injection index. The positron component measured with AMS-02 is consistent with a bump-like structure around 300 GeV in the CALET spectrum. One to three nearby supernovae can contribute up to a few tens of percent of the CALET flux at 2–4 TeV, while ten or more unknown and distant (≳500 pc) supernovae account for the remaining several tens of percent of the flux. The CALET spectrum, showing a sharp drop at ∼1 TeV, allows for a contribution of cosmic rays from an extraordinary event that occurred ∼400 kyr ago. This type of event releases electrons/positrons with a total energy more than 10 times the average energy for usual supernovae, and its occurrence rate is lower than one three-hundredth of the usual supernova rate.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We report the first measurement of the zodiacal light (ZL) polarization spectrum in the near-infrared between 0.8 and 1.8 <jats:italic>μ</jats:italic>m. Using the low-resolution spectrometer on board the Cosmic Infrared Background Experiment, calibrated for absolute spectrophotometry and spectropolarimetry, we acquire long-slit polarization spectral images of the total diffuse sky brightness toward five fields. To extract the ZL spectrum, we subtract the contribution of other diffuse radiation, such as the diffuse galactic light, the integrated starlight, and the extragalactic background light. The measured ZL polarization spectrum shows little wavelength dependence in the near-infrared, and the degree of polarization clearly varies as a function of the ecliptic coordinates and solar elongation. Among the observed fields, the North Ecliptic Pole shows the maximum degree of polarization of ∼20%, which is consistent with an earlier observation from the Diffuse Infrared Background Experiment on board on the Cosmic Background Explorer. The measured degree of polarization and its solar elongation dependence are reproduced by an empirical scattering model in the visible band and also by a Mie scattering model for large absorptive particles, while a Rayleigh scattering model is ruled out. All of our results suggest that the interplanetary dust is dominated by large particles.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Multiband emissions from radio to ultra-high-energy gamma-rays in the Crab Nebula have been detected. To explain the observed results, nonthermal photon production in the Crab Nebula is carefully studied in a spatially dependent lepto-hadronic model. In our model, the dynamical evolution of the pulsar wind nebula (PWN) is simulated in a spherically symmetric system. Both electrons and protons are accelerated at the termination shock. The relevant particle propagation equations, as well as the photon evolving equation, are simultaneously solved. For the Crab Nebula, our results reveal that the observed multiband photon spectra can be reproduced with reasonable model parameters. In particular, the photons with energy ≳200 TeV are mainly contributed to by the hadronic component via proton–proton interaction. The contribution of the hadronic component depends on both proton spectral index <jats:italic>α</jats:italic> <jats:sub>p</jats:sub> and number density <jats:italic>n</jats:italic> <jats:sub>H</jats:sub> of the medium within the PWN. Additionally, high-energy neutrino fluxes are predicted with variable proton spectral indices. The predicted fluxes are not only far below the sensitivities of current neutrino observatories but also beneath the atmospheric neutrino background with energy less than ∼40 TeV. Moreover, the calculated radial profiles of surface brightness and spectral index are presented.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The effects of cosmic-ray diffusion and radiative cooling on the structure of the Galactic wind are studied using a steady-state approximation. It is known that realistic cooling processes suppress the wind from launching. The effects of cosmic-ray diffusion are also supposed to be unfavorable for launching the wind. Both of these effects have not been studied simultaneously in a steady-state approximation of the wind. We find 327,254 solutions of the steady-state Galactic wind and confirm that: the effect of the cosmic-ray pressure depends on the Alfvén Mach number, the mass flux carried by the wind does not depend on the cosmic-ray pressure directly (but depends on the thermal pressure), and the typical conditions found in the Galaxy may correspond to the wind solution that provides metal-polluted matter at a height of ∼300 kpc from the disk.</jats:p>