Proper Motions of H2 Jets and Variability of Young Stars in the Serpens NW Region
Proper Motions of H2 Jets and Variability of Young Stars in the Serpens NW Region
复制标题
DOI：
10.1086/301003
复制
发表时间：
1999-09
期刊：
影响因子：
--
通讯作者：
K. Hodapp
中科院分区：
文献类型：
--
作者：
K. Hodapp
我们提出了深H2 1-0 S（1）线和连续图像，以及K-波段自行数据的系统发射结在巨蛇座西北地区。我们的数据表明，由这些结概述的射流起源于结“a”的SMM 9分子团在巨蛇座西北。发现了从星星EC 37中排出的分子物质残余物的运动学迹象，与SMM 1（FIRS 1）有关的喷流确实是按照其形态学所暗示的方向运动的。在近红外线中看到的靠近喷流顶点的暗淡星星（EC 41）几乎可以肯定与外流的驱动源不相同。与一些星云相关联的极红恒星被发现非常接近流出源S68 N/SMM 9和SMM 10的位置，这表明这些在K波段发现的恒星与在亚毫米波长检测到的物体相同。我们还报告了1995年发现的巨蛇座深埋爆发星星（DEOS）和其他年轻恒星的光度监测。在记录到最大值后的前290天内，DEOS的亮度最初急剧下降了0.84等，现在以0.33等/年的平均速度下降。它的光谱自发现以来已经发生了变化，现在显示出微弱的CO波段头部吸收的迹象。彗星状星云EC 53（与SMM 5有关）在1994年至1998年期间多次爆发，周期约为550天。这个I类源可能是EX Orionis变量。
We present deep H2 1–0 S(1) line and continuum images as well as K-band proper-motion data on a system of emission knots in the Serpens NW region. Our data demonstrate that the jet outlined by these knots originates in knot "a" of the SMM 9 molecular clump in Serpens NW. Kinematic indications for remnants of molecular material being expelled from the star EC 37 were found. The jet associated with SMM 1 (FIRS1) was shown indeed to move in the direction suggested by its morphology. The faint star (EC 41) seen in the near-infrared close to the apex of that jet is almost certainly not identical with the driving source of the outflow. Extremely red stars, associated with some nebulosity, were found very close to the positions of the outflow sources S68 N/SMM 9 and SMM 10, suggesting that these stars found in the K band are identical to the objects detected at submillimeter wavelengths. We also report on the photometric monitoring of the Serpens Deeply Embedded Outburst Star (DEOS), discovered in 1995 and other young stars in Serpens. After an initial steeper drop in brightness by 0.84 mag in the first 290 days after the recorded maximum, the DEOS brightness is now decreasing at a slower average rate of 0.33 mag yr-1. Its spectrum has changed since the time of discovery and now shows faint indications of CO band head absorption. The cometary nebula EC 53 (associated with SMM 5) shows repeated outbursts between 1994 and 1998; a periodicity of about 550 days is suggested. This Class I source is probably an EX Orionis variable.