B-fields in Star-forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main
Authors
Eswaraiah, C
Lee, CW
Hasegawa, T
Berry, D
Chen, M
Choi, Y
Choi, M
Dai, S
Diep, PN
Duan, Y
Fiege, J
Griffin, M
Han, I
Hayashi, S
Jeong, IG
Karoly, J
Liu, HL
Liu, T
Publication Date
2022Journal Title
Astrophysical Journal
ISSN
0004-637X
Publisher
American Astronomical Society
Volume
926
Issue
2
Language
en
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Kwon, W., Pattle, K., Sadavoy, S., Hull, C., Johnstone, D., Ward-Thompson, D., Francesco, J., et al. (2022). B-fields in Star-forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main. Astrophysical Journal, 926 (2) https://doi.org/10.3847/1538-4357/ac4bbe
Abstract
<jats:title>Abstract</jats:title>
<jats:p>We present 850 <jats:italic>μ</jats:italic>m polarimetric observations toward the Serpens Main molecular cloud obtained using the POL-2 polarimeter on the James Clerk Maxwell Telescope as part of the B-fields In STar-forming Region Observations survey. These observations probe the magnetic field morphology of the Serpens Main molecular cloud on about 6000 au scales, which consists of cores and six filaments with different physical properties such as density and star formation activity. Using the histogram of relative orientation (HRO) technique, we find that magnetic fields are parallel to filaments in less-dense filamentary structures where <jats:inline-formula>
<jats:tex-math>
<?CDATA ${N}_{{{\rm{H}}}_{2}}\lt 0.93\times {10}^{22}$?>
</jats:tex-math>
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<mml:mn>0.93</mml:mn>
<mml:mo>×</mml:mo>
<mml:msup>
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<mml:mn>10</mml:mn>
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<mml:mn>22</mml:mn>
</mml:mrow>
</mml:msup>
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<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bbeieqn1.gif" xlink:type="simple" />
</jats:inline-formula> cm<jats:sup>−2</jats:sup> (magnetic fields perpendicular to density gradients), while they are perpendicular to filaments (magnetic fields parallel to density gradients) in dense filamentary structures with star formation activity. Moreover, applying the HRO technique to denser core regions, we find that magnetic field orientations change to become perpendicular to density gradients again at <jats:inline-formula>
<jats:tex-math>
<?CDATA ${N}_{{{\rm{H}}}_{2}}\approx 4.6\times {10}^{22}$?>
</jats:tex-math>
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</jats:inline-formula> cm<jats:sup>−2</jats:sup>. This can be interpreted as a signature of core formation. At <jats:inline-formula>
<jats:tex-math>
<?CDATA ${N}_{{{\rm{H}}}_{2}}\approx 16\times {10}^{22}$?>
</jats:tex-math>
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<mml:mo>≈</mml:mo>
<mml:mn>16</mml:mn>
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<mml:mn>10</mml:mn>
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<jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjac4bbeieqn3.gif" xlink:type="simple" />
</jats:inline-formula> cm<jats:sup>−2</jats:sup>, magnetic fields change back to being parallel to density gradients once again, which can be understood to be due to magnetic fields being dragged in by infalling material. In addition, we estimate the magnetic field strengths of the filaments (<jats:italic>B</jats:italic>
<jats:sub>POS</jats:sub> = 60–300 <jats:italic>μ</jats:italic>G)) using the Davis–Chandrasekhar–Fermi method and discuss whether the filaments are gravitationally unstable based on magnetic field and turbulence energy densities.</jats:p>
Keywords
320, Interstellar Matter and the Local Universe
Identifiers
apjac4bbe, ac4bbe, aas30911
External DOI: https://doi.org/10.3847/1538-4357/ac4bbe
This record's URL: https://www.repository.cam.ac.uk/handle/1810/334364
Rights
Licence:
http://creativecommons.org/licenses/by/4.0/
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