Hwang, J;
Pattle, K;
Parsons, H;
Go, M;
Kim, J;
(2023)
Magnetic Fields in the Horsehead Nebula.
Astronomical Journal
, 165
(5)
, Article 198. 10.3847/1538-3881/acc460.
Preview |
Text
Hwang_2023_AJ_165_198.pdf - Published Version Download (1MB) | Preview |
Abstract
We present the first polarized dust emission measurements of the Horsehead Nebula, obtained using the POL-2 polarimeter on the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera on the James Clerk Maxwell Telescope. The Horsehead Nebula contains two submillimeter sources: a photodissociation region (PDR; SMM1) and a starless core (SMM2). We see well-ordered magnetic fields in both sources. We estimated plane-of-sky magnetic field strengths of 56 ± 9 and 129 ± 21 μG in SMM1 and SMM2, respectively, and obtained mass-to-flux ratios and Alfvén Mach numbers of less than 0.6, suggesting that the magnetic field can resist gravitational collapse and that magnetic pressure exceeds internal turbulent pressure in these sources. In SMM2, the kinetic and gravitational energies are comparable to one another, but less than the magnetic energy. We suggest a schematic view of the overall magnetic field structure in the Horsehead Nebula. Magnetic field lines in SMM1 appear to have been compressed and reordered during the formation of the PDR, while the likely more-embedded SMM2 may have inherited its field from that of the pre-shock molecular cloud. The magnetic fields appear to currently play an important role in supporting both sources.
| Type: | Article |
|---|---|
| Title: | Magnetic Fields in the Horsehead Nebula |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-3881/acc460 |
| Publisher version: | https://doi.org/10.3847/1538-3881/acc460 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| Keywords: | Molecular clouds (1072); Star formation (1569); Magnetic fields (994); Polarimetry (1278); Submillimeter astronomy (1647) |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10169184 |
Archive Staff Only
 |
View Item |
