EPoS Contribution
EPoS Contribution
Matching dust emission structures and magnetic field in high-latitude cloud L1642: comparing Herschel and Planck maps

Johanna Malinen
FSU, Tallahassee, US
The nearby high-latitude cloud L1642 is one of only two known very high latitude (|b| > 30 deg) clouds actively forming stars. This cloud is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g., of the effect of magnetic fields. We compare Herschel dust emission structures and magnetic field orientation revealed by Planck polarization maps in L1642, and also combine these with dynamic information from molecular line observations. The high-resolution Herschel data reveal a complex structure including a dense, compressed central blob with elongated extensions, low density striations, "fishbone" like structures with a spine and perpendicular striations, and a spiraling "tail". The Planck polarization data reveal an ordered magnetic field that pervades the cloud and is aligned with the surrounding low density striations. We show that there is a complex interplay between the cloud structure and large scale magnetic fields revealed by Planck polarization data at 10' resolution. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. We see a clear transition from aligned to perpendicular structures approximately at a column density of NH = 2 x 1021 cm-2. We conclude that Planck polarization data revealing the large scale magnetic field orientation can be very useful even when comparing to the finest structures in higher resolution data, e.g. Herschel at ~18" resolution.
Caption: Linear structures extracted from Herschel map compared with magnetic field observed by Planck
L. Montier, IRAP, FR
J. Montillaud, Institut Utinam, FR
M. Juvela, UH, FI
I. Ristorcelli, IRAP, FR
S.E. Clark, CU, US
O. Berne, IRAP, FR
J.-Ph. Bernard, IRAP, FR
V.-M. Pelkonen, Institut Utinam, FR
D.C. Collins, FSU, US
Key publication

Suggested Session: Magnetic Fields