A merger in the dusty, z=7.5 galaxy A1689-zD1?
A merger in the dusty, z=7.5 galaxy A1689-zD1?
复制标题
尘土飞扬的 z=7.5 星系 A1689-zD1 中的合并？
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
J. Zavala
中科院分区：
文献类型：
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作者：
K. Knudsen;D. Watson;D. Frayer;L. Christensen;A. Gallazzi;M. Michałowski;J. Richard;J. Zavala
引力透镜星系 A1689-zD1 是经光谱证实的最遥远的源之一 (z = 7.5)。它是已知最早检测到星际介质（ISM）的星系；使用阿塔卡马大型毫米波阵列 (ALMA) 检测粉尘排放。 A1689-zD1 在高红移尘埃发射体中也很不寻常，因为它是一个亚 L* 星系，因此对于在此红移的更典型星系中检测气体 ISM 具有良好的前景。我们使用 ALMA 在 6 和 7 波段以及绿岸望远镜 (GBT) 在 Q 波段观测了 A1689-zD1。为了研究 A1689-zD1 的结构，我们绘制了毫米热尘埃发射图，并找到了两个尺寸约为 0.4 - 1.7 kpc（透镜校正）的空间分量。粗略的空间形态与在近红外 HST 中观察到的相似，并指向扰动的动态状态，可能表明早期形成中的主要合并或盘。 ALMA 光度测定用于约束远红外光谱能量分布，产生尘埃温度（T 尘埃类似于 35-45 K，β = 1.5 - 2）。我们没有在 GBT 数据中检测到 CO(3-2) 线，观察到的 95% 上限为 0.3 mJy。我们发现 220.9 GHz 的 ALMA 频段 6 中的发射略有过量。如果这种过量是真实存在的，则可能是由于 z([C II]) = 7.603 处的 [C Pi] 158.8 μ m 谱线发射的。 [C 副产品] L-FIR 光度比的严格上限表明[C 副产品] 赤字类似于几个明亮的类星体和大规模星暴。
The gravitationally lensed galaxy A1689-zD1 is one of the most distant spectroscopically confirmed sources (z = 7.5). It is the earliest known galaxy where the interstellar medium (ISM) has been detected; dust emission was detected with the Atacama Large Millimetre Array (ALMA). A1689-zD1 is also unusual among high-redshift dust emitters as it is a sub-L* galaxy and is therefore a good prospect for the detection of gaseous ISM in a more typical galaxy at this redshift. We observed A1689-zD1 with ALMA in bands 6 and 7 and with the Green Bank Telescope (GBT) in band Q. To study the structure of A1689-zD1, we map the mm-thermal dust emission and find two spatial components with sizes about 0.4 - 1.7 kpc (lensing-corrected). The rough spatial morphology is similar to what is observed in the near-infrared with HST and points to a perturbed dynamical state, perhaps indicative of a major merger or a disc in early formation. The ALMA photometry is used to constrain the far-infrared spectral energy distribution, yielding a dust temperature (T-dust similar to 35-45 K for beta = 1.5 - 2). We do not detect the CO(3-2) line in the GBT data with a 95 per cent upper limit of 0.3 mJy observed. We find a slight excess emission in ALMA band 6 at 220.9 GHz. If this excess is real, it is likely due to emission from the [C Pi] 158.8 mu m line at z([C II]) = 7.603. The stringent upper limits on the [C coproduct] L-FIR luminosity ratio suggest a [C coproduct] deficit similar to several bright quasars and massive starbursts.