Interactions Between Gas Dynamics and Magnetic Fields in the Massive Dense Cores of the DR21 Filament

被引:8
作者
Ching, Tao-Chung [1 ,2 ,3 ,4 ]
Lai, Shih-Ping [1 ,2 ,5 ]
Zhang, Qizhou [3 ]
Girart, Josep M. [3 ,6 ,7 ]
Qiu, Keping [8 ,9 ]
Liu, Hauyu B. [10 ]
机构
[1] Natl Tsing Hua Univ, Inst Astron, Hsinchu 30013, Taiwan
[2] Natl Tsing Hua Univ, Dept Phys, Hsinchu 30013, Taiwan
[3] Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA
[4] Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China
[5] Acad Sinica, Inst Astron & Astrophys, POB 23-141, Taipei 10617, Taiwan
[6] CSIC, ICE, Can Magrans S-N, E-08193 Cerdanyola Del Valles, Catalonia, Spain
[7] IEEC, E-08034 Barcelona, Catalonia, Spain
[8] Nanjing Univ, Sch Astron & Space Sci, 163 Xianlin Ave, Nanjing 210023, Jiangsu, Peoples R China
[9] Nanjing Univ, Minist Educ, Key Lab Modern Astron & Astrophys, Nanjing 210023, Jiangsu, Peoples R China
[10] ESO, Karl Schwarzschild Str 2, D-85748 Garching, Germany
基金
中国国家自然科学基金;
关键词
ISM: clouds; ISM: individual objects (DR21); ISM: kinematics and dynamics; ISM: magnetic fields; stars: formation; submillimeter: ISM; TURBULENT AMBIPOLAR DIFFUSION; MOLECULAR ION SPECTRA; STAR-FORMATION; SUBMILLIMETER ARRAY; ALFVENIC TURBULENCE; CLOUDS; OUTFLOWS; REGION; DISK; SIO;
D O I
10.3847/1538-4357/aad9fc
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We report Submillimeter Array molecular line observations in the 345 GHz band of five massive dense cores, Cyg-N38, Cyg-N43, Cyg-N48, Cyg-N51, and Cyg-N53 in the DR21 filament. The molecular line data reveal several dynamical features of the cores: (1) prominent outflows in all cores seen in the CO and SiO lines, (2) significant velocity gradients in Cyg-N43 and Cyg-N48 seen in the (HCN)-C-13 and (HCO+)-C-13 lines suggesting 0.1 pc scale rotational motions, and (3) possible infalls in Cyg-N48 found in the SiO and SO lines. Comparing the molecular line data and our dust polarization data in Ching et al., we find that the gradients of line-of-sight velocities appear to be randomly oriented relative to the plane-of-sky magnetic fields. Our simulations suggest that this random alignment implies parallel or random alignment between the velocity gradients and magnetic fields in the three-dimensional space. The linewidths of (HCN)-C-13 emission are consistently wider than those of (HCO+)-C-13 emission in the 3 ''-10 '' detectable scales, which can be explained by the existence of ambipolar diffusion with maximum plane-of-the-sky magnetic field strengths of 1.9 mG and 5.1 mG in Cyg-N38 and Cyg-N48, respectively. Our results suggest that the gas dynamics may distort the magnetic fields of the cores of into complex structures and ambipolar diffusion could be important in dissipating the magnetic energies of the cores.
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页数:17
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