Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization
We perform numerical simulations of supersonic magnetohydrodynamic (MHD) turbulence and calculate Fourier power spectra of E - and B -modes arising from dust polarization. We pay close attention to the ratio of E -mode to B -mode spectra (a.k.a. E/B power asymmetry) on small spatial scales. We find...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ace10a |
| _version_ | 1827826261058125824 |
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| author | Jungyeon Cho |
| author_facet | Jungyeon Cho |
| author_sort | Jungyeon Cho |
| collection | DOAJ |
| description | We perform numerical simulations of supersonic magnetohydrodynamic (MHD) turbulence and calculate Fourier power spectra of E - and B -modes arising from dust polarization. We pay close attention to the ratio of E -mode to B -mode spectra (a.k.a. E/B power asymmetry) on small spatial scales. We find that the ratio depends on the strength of the mean magnetic field: the stronger the mean magnetic field, the smaller the ratio. More precisely speaking, the ratio scales with the Alfvén Mach number M _A , the rms velocity divided by the Alfvén speed of the mean magnetic field, when it lies in the range 1 ≲ M _A ≲ 30. This result implies that we can use the E/B power asymmetry to constrain the strength of the mean magnetic field in supersonic and super-Alfvénic MHD turbulence. |
| first_indexed | 2024-03-12T03:02:22Z |
| format | Article |
| id | doaj.art-a9da00166b69459f846cf42634feb255 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:02:22Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-a9da00166b69459f846cf42634feb2552023-09-03T14:39:27ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01953111410.3847/1538-4357/ace10aObtaining the Strength of the Magnetic Field from E- and B-Modes of Dust PolarizationJungyeon Cho0https://orcid.org/0000-0003-1725-4376Department of Astronomy and Space Science, Chungnam National University , Daejeon, Republic of Korea ; jcho@cnu.ac.krWe perform numerical simulations of supersonic magnetohydrodynamic (MHD) turbulence and calculate Fourier power spectra of E - and B -modes arising from dust polarization. We pay close attention to the ratio of E -mode to B -mode spectra (a.k.a. E/B power asymmetry) on small spatial scales. We find that the ratio depends on the strength of the mean magnetic field: the stronger the mean magnetic field, the smaller the ratio. More precisely speaking, the ratio scales with the Alfvén Mach number M _A , the rms velocity divided by the Alfvén speed of the mean magnetic field, when it lies in the range 1 ≲ M _A ≲ 30. This result implies that we can use the E/B power asymmetry to constrain the strength of the mean magnetic field in supersonic and super-Alfvénic MHD turbulence.https://doi.org/10.3847/1538-4357/ace10aInterstellar dustInterstellar magnetic fieldsInterplanetary turbulencePolarimetry |
| spellingShingle | Jungyeon Cho Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization The Astrophysical Journal Interstellar dust Interstellar magnetic fields Interplanetary turbulence Polarimetry |
| title | Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization |
| title_full | Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization |
| title_fullStr | Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization |
| title_full_unstemmed | Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization |
| title_short | Obtaining the Strength of the Magnetic Field from E- and B-Modes of Dust Polarization |
| title_sort | obtaining the strength of the magnetic field from e and b modes of dust polarization |
| topic | Interstellar dust Interstellar magnetic fields Interplanetary turbulence Polarimetry |
| url | https://doi.org/10.3847/1538-4357/ace10a |
| work_keys_str_mv | AT jungyeoncho obtainingthestrengthofthemagneticfieldfromeandbmodesofdustpolarization |