The relative orientation between local magnetic field and Galactic plane in low latitude dark clouds

Abstract

In this work, we study the magnetic field morphology of selected star-forming clouds spread over the galactic latitude ($b$) range, $-10^{\circ }$ to $10^{\circ }$. The polarimetric observation of clouds CB24, CB27 and CB188 are conducted to study the magnetic field geometry of those clouds from ARIES, Manora Peak, Nainital, India. These observations are combined with those of 14 further low latitude clouds available in the literature. Analyzing the polarimetric data of 17 clouds, we find that the alignment between the envelope magnetic field (${\theta }_B^{env}$) and Galactic plane (${\theta }_{GP}$) of the low-latitude clouds varies with their galactic longitudes ($l$). We observe a strong correlation between the longitude (\textit{l}) and the offset (${\theta }_{off}=|{\theta }_B^{env}-{\theta }_{GP}|$) which shows that ${\theta }_B^{env}$ is parallel to the Galactic plane (GP) when the clouds are situated in the region, $115^{\circ }<l<250^{\circ }$. However, ${\theta }_B^{env}$ has its own local deflection irrespective of the orientation of ${\theta }_{GP}$ when the clouds are at $l<100^{\circ }$ and $l>250^{\circ }$. To check the consistency of our results, the stellar polarization data available at Heiles (2000) catalogue are overlaid on DSS image of the clouds having mean polarization vector of field stars. The results are almost consistent with the Heiles data. The effect of turbulence of the cloud is also studied which may play an important role in causing the misalignment phenomenon observed between ${\theta }_B^{env}$ and ${\theta }_{GP}$. We have used \textit{Herschel} \textit{SPIRE} 500 $\mu m$ and \textit{SCUBA} 850 $\mu m$ dust continuum emission maps in our work to understand the density structure of the clouds.

22 pages, 7 figures. This is the Accepted Manuscript version of an article accepted for publication in Research in Astronomy and Astrophysics. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. This Accepted Manuscript is published under a CC BY licence. The Version of Record is available soon online

References in corpus (17)

• The Gaia mission
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• The impact of magnetic fields on single and binary star formation
• The effect of magnetic fields on star cluster formation
• Grain Alignment by Radiative Torques in Special Conditions and Implications
• Gaia Early Data Release 3: Acceleration of the solar system from Gaia astrometry
• OVRO N2H+ Observations of Class 0 Protostars: Constraints on the Formation of Binary Stars
• Optical polarimetric study of open clusters: Distribution of Interstellar matter towards NGC 654
• Modeling Grain Alignment by Radiative Torques and Hydrogen Formation Torques in Reflection Nebula
• The Effect of Supernovae on the Turbulence and Dispersal of Molecular Clouds
• Constraining the magnetic field properties of Bok globule B335 using SOFIA/HAWC+
• Study of background star polarization and polarization efficiency of three selected Bok globules CB56, CB60 and CB69
• Bok globule CB17: Polarization, extinction and distance
• Probing the magnetic fields in L1415 and L1389
• Study of magnetic field geometry and extinction in Bok globule CB130
• Distance estimation of some selected small Bok globules
• Magnetic field geometry of the large globule CB 34

Cited by in corpus (1)

• A Survey of Magnetic Field Properties in Bok Globules