论文标题
低纬度乌云中局部磁场和银河平面之间的相对取向
The relative orientation between local magnetic field and Galactic plane in low latitude dark clouds
论文作者
论文摘要
在这项工作中,我们研究了分布在银河纬度($ b $)范围内的选定星形成云的磁场形态,$ -10^\ circ $ to $ 10^\ circ $。对云CB24,CB27和CB188的极化观察进行了研究,以研究来自印度奈尼塔尔的Manora Peak,Manora Peak的这些云的磁场几何形状。这些观察结果与文献中可用的14个低纬度云相结合。分析17个云的极化数据,我们发现信封磁场($θ_{b}^{env} $)与低纬度云的银河平面($θ_{gp} $)之间的对齐方式有所不同。我们观察到经度(\ textit {l})与偏移($θ_{off} = |θ_b^{envy} -temp} -temp} {gp} | $)之间的密切相关性$ 115^\ circ <l <250^\ circ $。但是,$θ_{b}^{env} $都有其自己的本地挠度,无论$θ_{gp} $的方向如何,当云处为$ l <100^\ circ $和$ l> 250^\ circ $时。为了检查我们的结果的一致性,Heiles(2000)目录中可用的恒星极化数据被覆盖在具有田间恒星平均极化向量的云的DSS图像上。结果几乎与Heiles数据一致。还研究了云的湍流的影响,这可能在导致$θ_{b}^{envy} $和$θ_{gp} $之间观察到的未对准现象。我们已经使用了\ textIt {herschel} \ textit {spire} 500 $μm$和\ textit {Scuba} 850 $μm$ dust duck continuum发射图在我们的工作中了解云的密度结构。
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 ($θ_{B}^{env}$) and Galactic plane ($θ_{GP}$) of the low-latitude clouds varies with their galactic longitudes ($l$). We observe a strong correlation between the longitude (\textit{l}) and the offset ($θ_{off}=|θ_B^{env}-θ_{GP}|$) which shows that $θ_{B}^{env}$ is parallel to the Galactic plane (GP) when the clouds are situated in the region, $115^\circ<l<250^\circ$. However, $θ_{B}^{env}$ has its own local deflection irrespective of the orientation of $θ_{GP}$ 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 $θ_{B}^{env}$ and $θ_{GP}$. We have used \textit{Herschel} \textit{SPIRE} 500 $μm$ and \textit{SCUBA} 850 $μm$ dust continuum emission maps in our work to understand the density structure of the clouds.