Ammonia downstream from HH 80 North
Ammonia downstream from HH 80 North
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HH 80 North 下游的氨
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
A. Noriega
中科院分区：
文献类型：
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作者：
J. Girart;Luis F. Rodriguez;G. Anglada;R. Estalella;J. Torrelles;J. Martí;M. Peña;S. Ayala;S. Curiel;A. Noriega
HH 80-81 是两个光学可见的赫比格-哈罗 (HH) 天体，位于其令人兴奋的源 IRAS 18162-2048 以南约 5 分钟处。最近检测到一个可能的 HH 对应物，对称地放置在这个发光 IRAS 源的北部，它是具有超大型阵列 (VLA) 的射电连续谱源。这个射电源，HH 80 North，被认为是赫比格-哈罗类的一员，因为它的厘米通量密度、角大小、光谱指数和形态都与 HH 80 相似。然而，在 HH 80 North 位置的光波长下没有检测到物体，可能是因为消光度很高，并且不可能确认射电连续谱源是 HH 天体。在典型的赫比格-哈罗天体 HH 1 和 2 中，在两个天体的流动下游均检测到氨排放。该检测被解释为与 HH 物体相关的冲击辐射场产生的氨排放增强的结果。在这封信中，我们报告了 HH 80 North 下游氨的 (1,1) 和 (2,2) 反转跃迁的检测。这次探测有力地支持了 HH 80 North 被严重遮挡的 HH 天体的解释。此外，我们认为氨排放可能是恒星形成其他区域嵌入的赫比格-哈罗天体的示踪剂。 60 微米 IRAS 源可能与 HH 80 North 和氨凝结有关。对 HH 物体的光学和紫外线辐射加热的尘埃中产生的远红外发射提出了初步解释。
HH 80-81 are two optically visible Herbig-Haro (HH) objects located about 5 minutes south of their exciting source IRAS 18162-2048. Displaced symmetrically to the north of this luminous IRAS source, a possible HH counterpart was recently detected as a radio continuum source with the very large array (VLA). This radio source, HH 80 North, has been proposed to be a member of the Herbig-Haro class since its centimeter flux density, angular size, spectral index, and morphology are all similar to those of HH 80. However, no object has been detected at optical wavelengths at the position of HH 80 North, possibly because of high extinction, and the confirmation of the radio continuum source as an HH object has not been possible. In the prototypical Herbig-Haro objects HH 1 and 2, ammonia emission has been detected downstream of the flow in both objects. This detection has been intepreted as a result of an enhancement in the ammonia emission produced by the radiation field of the shock associated with the HH object. In this Letter we report the detection of the (1,1) and (2,2) inversion transitions of ammonia downstream HH 80 North. This detection gives strong suppport to the interpretation of HH 80 North as a heavily obscured HH object. In addition, we suggest that ammonia emission may be a tracer of embedded Herbig-Haro objects in other regions of star formation. A 60 micrometer IRAS source could be associated with HH 80 North and with the ammonia condensation. A tentative explanation for the far-infrared emission as arising in dust heated by their optical and UV radiation of the HH object is presented.