Detection of FeO toward Sagittarius B2
Detection of FeO toward Sagittarius B2
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检测到人马座 B2 的 FeO
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
P. Schilke
中科院分区：
文献类型：
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作者：
C. Walmsley;R. Bachiller;G. Forêts;P. Schilke
我们观察到了在153 GHz频率下，FeO的J=5-4基态跃迁，指向某些银河系源。对于银河系中心震源SGR B2，我们看到弱吸收的速度与该震源的其他特征的速度大致相同(62公里S-1LSR)。对于其他来源，结果是否定的，他们也是对氢氧化镁(3-2)和铁电石(6-5)。我们初步得出结论，对SGRB2的吸收是由于FeO处于热的(~500K)，密度相对较低，吸收了这条视线上已知的气体。这是首次(尽管是试探性的)在星际气体中检测到FeO或任何含铁分子。假设观测到的吸收是由FeO引起的，我们估计[FeO]/[SiO]约为0.002量级，[FeO]/[H2]约为3×10-11量级。这与我们在其他来源的负面结果是一致的。我们的结果表明，在与SgrB2相关的激波中，从颗粒中释放出来的铁仍然是原子的，没有被加工成分子形式。
We have observed the J = 5-4 ground-state transition of FeO at a frequency of 153 GHz toward a selection of Galactic sources. Toward the Galactic center source Sgr B2, we see weak absorption at approximately the velocity of other features toward this source (62 km s-1 LSR). Toward other sources, the results were negative, as they were also for MgOH (3-2) and FeC (6-5). We tentatively conclude that the absorption seen toward Sgr B2 is due to FeO in the hot (~500 K), relatively low density, absorbing gas known to be present in this line of sight. This is the first (albeit tentative) detection of FeO or any iron-containing molecule in the interstellar gas. Assuming the observed absorption to be due to FeO, we estimate the [FeO]/[SiO] to be of the order of or less than 0.002, and the [FeO]/[H2] of the order of 3 × 10-11. This is compatible with our negative results in other sources. Our results suggest that the iron liberated from grains in the shocks associated with Sgr B2 remains atomic and is not processed into molecular form.