Tomographic Imaging of the Sagittarius Spiral Arm's Magnetic Field Structure

• DOI: 10.3847/1538-4357/ad0fe2
• Publication Date: 2024-01-11T09:10:57Z
• Authors: Yasuo 靖生 Doi 土井; Kengo 謙吾 Nakamura 中村; Koji S. 弘治 Kawaba...; Masafumi 雅文 Matsu...; Hiroshi 谷洋 Akitay...; Simon Coudé; Claudia V. Rodrigues; Jungmi 靜美 Kwon 權; Motohide 元秀 Tamur...; Mehrnoosh Tahani; Antonio Mario Mag...; Reinaldo Santos-Lima; Yenifer Angarita; José Versteeg; Marijke Haverkorn; Tetsuo 川哲夫 Hasega...; Sarah Sadavoy; Doris Arzoumanian; Pierre Bastien
• Keywords: Galactic plane; Sagittarius A*; Sagittarius; Line-of-sight

Abstract The Galactic global magnetic field is thought to play a vital role in shaping structures such as spiral arms and giant molecular clouds. However, our knowledge of the plane at different distances limited, measurements used map are integrated effect along line sight. In this study, we present first ever tomographic imaging arm. Using optical stellar polarimetry over <?CDATA $17^{\prime} \times 10^{\prime} $?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>17</mml:mn> <mml:mo accent="false">′</mml:mo> <mml:mo>×</mml:mo> <mml:mn>10</mml:mn> </mml:math> view, probe Sagittarius Combining these data with from Gaia mission, can isolate contributions five individual clouds sight by analyzing function distance. observed include foreground cloud ( d &lt; 200 pc) four arm 1.23, 1.47, 1.63, 2.23 kpc. column densities range 0.5 2.8 × 10 21 cm −2 . fields associated each show smooth spatial distributions within their regions on scales smaller than pc display distinct orientations. position angles projected sky, measured north east, for increasing order distance 135°, 46°, 58°, 150°, 40°, uncertainties few degrees. Notably, deviate significantly direction parallel plane.