ROTATING BULLETS FROM A VARIABLE PROTOSTAR

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 分子云与恒星形成研究团组

	ROTATING BULLETS FROM A VARIABLE PROTOSTAR
	Chen, Xuepeng; Arce, Hector G.; Zhang, Qizhou; Launhardt, Ralf; Henning, Thomas
刊名	ASTROPHYSICAL JOURNAL
	2016
卷号	824 期号:2 页码:72
英文摘要	We present Submillimeter Array (SMA) CO (2-1) observations toward the protostellar jet driven by SVS 13 A, a variable protostar in the NGC 1333 star-forming region. The SMA CO (2-1) images show an extremely high velocity jet composed of a series of molecular "bullets." Based on the SMA CO observations, we discover clear and large systematic velocity gradients, perpendicular to the jet axis, in the blueshifted and redshifted bullets. After discussing several alternative interpretations, such as twin-jets, jet precession, warped disk, and internal helical shock, we suggest that the systematic velocity gradients observed in the bullets result from the rotation of the SVS 13 A jet. From the SMA CO images, the measured rotation velocities are 11.7-13.7 km s(-1) for the blueshifted bullet and 4.7 +/- 0.5 km s(-1) for the redshifted bullet. The estimated specific angular momenta of the two bullets are comparable to those of dense cores, about 10 times larger than those of protostellar envelopes, and about 20 times larger than those of circumstellar disks. If the velocity gradients are due to the rotation of the SVS 13 A jet, the significant amount of specific angular momenta of the bullets indicates that the rotation of jets/outflows is a key mechanism to resolve the so-called "angular momentum problem" in the field of star formation. The kinematics of the bullets suggests that the jet launching footprint on the disk has a radius of similar to 7.2-7.7 au, which appears to support the extended disk-wind model. We note that further observations are needed to comprehensively understand the kinematics of the SVS 13 A jet, in order to confirm the rotation nature of the bullets.
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/16818]
专题	紫金山天文台_分子云与恒星形成研究团组
推荐引用方式 GB/T 7714	Chen, Xuepeng,Arce, Hector G.,Zhang, Qizhou,et al. ROTATING BULLETS FROM A VARIABLE PROTOSTAR[J]. ASTROPHYSICAL JOURNAL,2016,824(2):72.
APA	Chen, Xuepeng,Arce, Hector G.,Zhang, Qizhou,Launhardt, Ralf,&Henning, Thomas.(2016).ROTATING BULLETS FROM A VARIABLE PROTOSTAR.ASTROPHYSICAL JOURNAL,824(2),72.
MLA	Chen, Xuepeng,et al."ROTATING BULLETS FROM A VARIABLE PROTOSTAR".ASTROPHYSICAL JOURNAL 824.2(2016):72.