A LARGE-SCALE SPECTROSCOPIC SURVEY OF METHANOL AND OH LINE EMISSION FROM THE GALACTIC CENTER: OBSERVATIONS AND DATA
A LARGE-SCALE SPECTROSCOPIC SURVEY OF METHANOL AND OH LINE EMISSION FROM THE GALACTIC CENTER: OBSERVATIONS AND DATA
复制标题
银河系中心甲醇和 OH 线排放的大规模光谱调查：观测和数据
DOI：
10.3847/0067-0049/227/1/10
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
F. Yusef
中科院分区：
文献类型：
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作者：
W. Cotton;F. Yusef
I 类甲醇脉泽是碰撞泵浦的，通常与银河系恒星形成地点的流出相关。我们使用 A 阵列配置中的甚大阵列进行谱线调查，以识别 36.169 GHz 处的甲醇发射。使用了 900 多个指向来覆盖沿着内银河平面的 66' × 13' 区域。我们还在甲醇调查覆盖的区域内对 1612、1665、1667 和 1720 MHz 的 OH 进行了浅层调查。我们提供了 2240 个甲醇微波激射器的目录，其窄线宽为 ∼1 km s−1，空间分辨率为 ，每通道均方根噪声为 ∼20 mJy beam−1。亮度温度下限范围为 27,000 至 10,000,000 K，表明发射是非热源的。我们还提供了 23 个 OH (1612)、14 个 OH (1665)、5 个 OH (1667) 和 5 个 OH (1720 MHz) 微波激射器的列表。如此大量的甲醇脉泽的来源尚不清楚。许多甲醇脉泽似乎与红外暗云有关，尽管这些脉泽的全部群体似乎不太可能追踪银河系中心恒星形成的早期阶段。
Class I methanol masers are collisionally pumped and are generally correlated with outflows in star-forming sites in the Galaxy. Using the Very Large Array in its A-array configuration, we present a spectral line survey to identify methanol emission at 36.169 GHz. Over 900 pointings were used to cover a region 66′ × 13′ along the inner Galactic plane. A shallow survey of OH at 1612, 1665, 1667, and 1720 MHz was also carried out over the area covered by our methanol survey. We provide a catalog of 2240 methanol masers with narrow line-widths of ∼1 km s−1, spatial resolutions of , and rms noises ∼20 mJy beam−1 per channel. Lower limits on the brightness temperature range from 27,000 to 10,000,000 K, showing that the emission is of non-thermal origin. We also provide a list of 23 OH (1612), 14 OH (1665), 5 OH (1667), and 5 OH (1720 MHz) masers. The origin of such a large number of methanol masers is not clear. Many methanol masers appear to be associated with infrared dark clouds, though it appears unlikely that the entire population of these masers trace the early phase of star formation in the Galactic center.