论文标题
APEX-SEPIA660早期科学：高于$ 10^7 $ cm $^{ - 3} $的气体对OMC-1
APEX-SEPIA660 Early Science: Gas at densities above $10^7$ cm$^{-3}$ towards OMC-1
论文作者
论文摘要
语境。在年轻的大型集群中发现的星形率和出色的密度表明，这些恒星系统来自密度N的气体（H $ _2 $）$> 10^7 $ cm $ $^{ - 3} $。然而，直到今天，这种超高密度材料的物理表征在观察结果中仍然在很大程度上不受限制。目标。我们研究了位于猎户座星云群（ONC）附近的OMC-1区域中恒星形成气体的密度特性。方法。作为APEX-SEPIA660早期科学的一部分，我们在OMC-1中将分子发射映射为652 GHz。结果。我们检测到沿整个OMC-1区域的Bright and Extended N $ _2 $ H $^+$（J = 7-6）线排放。 （J = 1-0）过渡和辐射转移模型的先前ALMA数据的比较表明，在此N $ _2 $ _2 $ _2 $ H $^+$（7-6）线中观察到的线强度是由大量质量储量的密度n（H $ _2 $ _2 $> 10^7 $> 10^7 $ cm $ $ cm $^$^3} $。结论。在Parsec-Scales的这款N $ _2 $ H $^+$（7-6）线的第一次检测表明，在年轻的大型群集（例如ONC）中，星形形成气体的极端密度条件。我们的结果突出了新的SEPIA660接收器的灵敏度和映射功能的独特组合，用于研究ISM属性的高频。
Context. The star formation rates and stellar densities found in young massive clusters suggest that these stellar systems originate from gas at densities n(H$_2$) $>10^7$ cm$^{-3}$. Until today, however, the physical characterization of this ultra high density material remains largely unconstrained in observations. Aims. We investigated the density properties of the star-forming gas in the OMC-1 region located in the vicinity of the Orion Nebula Cluster (ONC). Methods. We mapped the molecular emission at 652 GHz in OMC-1 as part of the APEX-SEPIA660 Early Science. Results. We detect bright and extended N$_2$H$^+$ (J=7-6) line emission along the entire OMC-1 region. Comparisons with previous ALMA data of the (J=1-0) transition and radiative transfer models indicate that the line intensities observed in this N$_2$H$^+$ (7-6) line are produced by large mass reservoirs of gas at densities n(H$_2$) $>10^7$ cm$^{-3}$. Conclusions. The first detection of this N$_2$H$^+$ (7-6) line at parsec-scales demonstrates the extreme density conditions of the star-forming gas in young massive clusters such as the ONC. Our results highlight the unique combination of sensitivity and mapping capabilities of the new SEPIA660 receiver for the study of the ISM properties at high frequencies.
