Detection of molecular gas in a distant submillimetre galaxy at z=4.76 with ATCA
Detection of molecular gas in a distant submillimetre galaxy at z=4.76 with ATCA
复制标题
DOI：
10.1111/j.1745-3933.2010.00914.x
复制
发表时间：
2010-04
期刊：
影响因子：
--
通讯作者：
K. Coppin;S. Chapman;I. Smail;M. Swinbank;F. Walter;J. Wardlow;A. Weiss;D. Alexander;N. Brandt;H. Dannerbauer;C. Breuck;M. Dickinson;J. Dunlop;A. Edge;B. Emonts;T. Greve;M. Huynh;R. Ivison;K. Knudsen;K. Menten;E. Schinnerer;P. Werf
中科院分区：
文献类型：
--
作者：
K. Coppin;S. Chapman;I. Smail;M. Swinbank;F. Walter;J. Wardlow;A. Weiss;D. Alexander;N. Brandt;H. Dannerbauer;C. Breuck;M. Dickinson;J. Dunlop;A. Edge;B. Emonts;T. Greve;M. Huynh;R. Ivison;K. Knudsen;K. Menten;E. Schinnerer;P. Werf
我们在澳大利亚望远镜紧凑型阵列上使用新的紧凑型阵列宽带后端系统探测到了从亚毫米星系LESSJ033229.4-275619在z=4.755的CO(2-1)跃迁。我们利用CO(2--1)谱线的光度和速度宽度(半高宽160公里/S)分别约束了MGA的气体质量和动力学质量，分别为1.6×10~(-10)MSun和5×10~(10)(0.25/Sin^2(I))MSun，与在z~2-4的较低红移的SMG中观测到的相似，尽管我们注意到我们观测到的CO FWHM比SMG中通常看到的窄~3倍。连同恒星质量，我们估计了Mbary~1×10^11mSun的总重子质量，这与这个年轻星系的动力学质量在不确定范围内是一致的。高红移星系的动力学和重子质量极限是对星系形成模型的有用检验：以已知的z~4-5SMG为例，我们发现它们的空间密度与现有星系形成模型所预测的一致。此外，这些观测还有助于证实z~4-5 SMG具有重子质量和气体消耗时间标度，是在z~3看到的发光的古老红色星系的前身。我们的结果为ALMA在宇宙中最早的大质量星系的形成和演化提供了科学的预告。
We have detected the CO(2-1) transition from the submillimetre galaxy (SMG) LESSJ033229.4-275619 at z=4.755 using the new Compact Array Broadband Backend system on the Australian Telescope Compact Array. These data have identified a massive gas reservoir available for star formation for the first time in an SMG at z~5. We use the luminosity and velocity width (FWHM of 160 km/s) of the CO(2--1) line emission to constrain the gas and dynamical mass of Mgas~1.6x10^10 Msun and Mdyn(<2kpc)~5x10^10 (0.25/sin^2(i)) Msun, respectively, similar to that observed for SMGs at lower redshifts of z~2-4, although we note that our observed CO FWHM is a factor of ~3 narrower than typically seen in SMGs. Together with the stellar mass we estimate a total baryonic mass of Mbary~1x10^11 Msun, consistent with the dynamical mass for this young galaxy within the uncertainties. Dynamical and baryonic mass limits of high-redshift galaxies are useful tests of galaxy formation models: using the known z~4-5 SMGs as examples of massive baryonic systems, we find that their space density is consistent with that predicted by current galaxy formation models. In addition, these observations have helped to confirm that z~4-5 SMGs possess the baryonic masses and gas consumption timescales necessary to be the progenitors of the luminous old red galaxies seen at z~3. Our results provide a preview of the science that ALMA will enable on the formation and evolution of the earliest massive galaxies in the Universe.