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<jats:title>Abstract</jats:title> <jats:p>We present new-generation mechanisms of magnetic fields in supernova remnant shocks propagating to partially ionized plasmas in the early universe. Upstream plasmas are dissipated at the collisionless shock, but hydrogen atoms are not dissipated because they do not interact with electromagnetic fields. After the hydrogen atoms are ionized in the shock downstream region, they become cold proton beams that induce the electron return current. The injection of the beam protons can be interpreted as an external force acting on the downstream proton plasma. We show that the effective external force and the electron return current can generate magnetic fields without any seed magnetic fields. The magnetic field strength is estimated to be <jats:inline-formula> <jats:tex-math> <?CDATA $B\sim {10}^{-14}\mbox{--}{10}^{-11}\,{\rm{G}}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>B</mml:mi> <mml:mo>∼</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>14</mml:mn> </mml:mrow> </mml:msup> <mml:mo>–</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>11</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.50em" /> <mml:mi mathvariant="normal">G</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac23d1ieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, where the characteristic length scale is the mean free path of charge exchange, <jats:inline-formula> <jats:tex-math> <?CDATA $\sim {10}^{15}\,\mathrm{cm}$?> </jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>∼</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>15</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.50em" /> <mml:mi>cm</mml:mi> </mml:math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac23d1ieqn2.gif" xlink:type="simple" /> </jats:inline-formula>. Since protons are marginally magnetized by the generated magnetic field in the downstream region, the magnetic field could be amplified to larger values and stretched to larger scales by turbulent dynamo and expansion.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We have performed the first comprehensive statistical analysis comparing flux rope (FR) structures of coronal mass ejections (CMEs) near the Sun and at 1 au, using Solar and Heliospheric Observatory and Solar Terrestrial Relations Observatory measurements for the two full solar cycles 23 and 24. This study aims to investigate the physical connection of 102 magnetic FRs among solar source regions, CMEs in the extended corona, and magnetic clouds (MCs) near Earth. Our main results are as follows: (1) We confirmed that the hemispheric-helicity rule holds true for ∼87% of our 102 events. For the 13 events that do not follow this rule, the FR axis directions and helicity signs can be inferred from soft X-ray and extreme ultraviolet images and magnetogram data in the source regions (e.g., coronal arcade skews, Fe <jats:sc>xii</jats:sc> stalks, sigmoids, and magnetic tongues). (2) Around 25% of the 102 events have rotations &gt;40° between the MC and CME-FR axial orientations. (3) For ∼56% of these rotational events, the FR rotations occurred within the COR2 field of view, which can be predicted from the CME tilts obtained from FR fitting models. In addition, we found that for 89% of the 19 stealth CMEs under study, we were able to use coronal neutral line locations and tilts to predict the FR helicity and its axial direction in the MCs. The above results should help improve the prediction of FR structures in situ. We discuss their implications on space weather forecasts.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a sounding rocket experiment that observes the soft X-ray spectrum of the Sun from 6.0–24 Å (0.5–2.0 keV), successfully launched on 2021 July 30. End-to-end alignment of the flight instrument and calibration experiments are carried out using the X-ray and Cryogenic Facility at NASA Marshall Space Flight Center. In this paper, we present the calibration experiments of MaGIXS, which include wavelength calibration, measurement of line spread function, and determination of effective area. Finally, we use the measured instrument response function to predict the expected count rates for MaGIXS flight observation looking at a typical solar active region.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We present Very Large Array <jats:italic>C-</jats:italic>, <jats:italic>X-</jats:italic>, and <jats:italic>Q</jats:italic>-band continuum observations, as well as 1.3 mm continuum and CO(2-1) observations with the Submillimeter Array toward the high-mass protostellar candidate ISOSS J23053+5953 SMM2. Compact centimeter continuum emission was detected near the center of the SMM2 core with a spectral index of 0.24(± 0.15) between 6 and 3.6 cm, and a radio luminosity of 1.3(±0.4) mJy kpc<jats:sup>2</jats:sup>. The 1.3 mm thermal dust emission indicates a mass of the SMM2 core of 45.8 (±13.4) <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>, and a density of 7.1 (±1.2)× 10<jats:sup>6</jats:sup> cm<jats:sup>−3</jats:sup>. The CO(2-1) observations reveal a large, massive molecular outflow centered on the SMM2 core. This fast outflow (&gt;50 km s<jats:sup>−1</jats:sup> from the cloud systemic velocity) is highly collimated, with a broader, lower-velocity component. The large values for outflow mass (45.2 ± 12.6 <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub>) and momentum rate (6 ± 2 × 10<jats:sup>−3</jats:sup> <jats:italic>M</jats:italic> <jats:sub>⊙</jats:sub> km s<jats:sup>−1</jats:sup>yr<jats:sup>−1</jats:sup>) derived from the CO emission are consistent with those of flows driven by high-mass YSOs. The dynamical timescale of the flow is between 1.5 and 7.2 × 10<jats:sup>4</jats:sup> yr. We also found from the C<jats:sup>18</jats:sup>O to thermal dust emission ratio that CO is depleted by a factor of about 20, possibly due to freeze-out of CO molecules on dust grains. Our data are consistent with previous findings that ISOSS J23053 + 5953 SMM2 is an emerging high-mass protostar in an early phase of evolution, with an ionized jet and a fast, highly collimated, and massive outflow.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The centroid energy of the Fe K<jats:italic>α</jats:italic> line has been used to identify the progenitors of supernova remnants (SNRs). These investigations generally considered the energy of the centroid derived from the spectrum of the entire remnant. Here we use XMM-Newton data to investigate the Fe K<jats:italic>α</jats:italic> centroid in 6 SNRs: 3C 397, N132D, W49B, DEM L71, 1E 0102.2-7219, and Kes 73. In Kes 73 and 1E 0102.2-7219, we fail to detect any Fe K<jats:italic>α</jats:italic> emission. We report a tentative first detection of Fe K<jats:italic>α</jats:italic> emission in SNR DEM L71 with a centroid energy consistent with its Type Ia designation. In the remaining remnants, the spatial and spectral sensitivity is sufficient to investigate spatial variations of the Fe K<jats:italic>α</jats:italic> centroid. We find in N132D and W49B that the centroids in different regions are consistent with those derived from the overall spectrum, although not necessarily with the remnant type identified via other means. However, in SNR 3C 397, we find statistically significant variation in the centroid of up to 100 eV, aligning with the variation in the density structure around the remnant. These variations span the intermediate space between centroid energies signifying core-collapse (CC) and Type Ia remnants. Shifting the dividing line downwards by 50 eV can place all the centroids in the CC region, but contradicts the remnant type obtained via other means. Our results show that caution must be used when employing the Fe K<jats:italic>α</jats:italic> centroid of the entire remnant as the sole diagnostic for typing a remnant.</jats:p>