论文标题
阿尔玛揭示了在3 <z <3.5的主序列上5颗恒星星系的分子气体性质
ALMA reveals the molecular gas properties of 5 star-forming galaxies across the main sequence at 3 < z < 3.5
论文作者
论文摘要
我们介绍了具有S/N> 7-13的CO（5-4）的检测，以及与S/N> 3（CO（4-3）的较低CO过渡，用于4个星系，而CO（3-2）的CO（3-2），ALMA中的ALMA中的ALMA中的ALMA和4个主要序列星形星系中具有3-6x10^10 m/m_sun at 3-6x10^10 m/m_sun at 3 <z <3.5。我们发现总远红外光度LFIR与CO（5-4）过渡L'CO（5-4）的光度之间存在良好的相关性，其中L'CO（5-4）随SFR的增加而增加，这表明CO（5-4）是这些星系中SFR的良好轨迹。靠近星形主序列的两个星系具有与其他恒星形成种群相当的斜坡，例如局部SMG和BZK恒星形成的星系。具有较高特异性恒星形成速率（SSFR）的三个物体具有较陡的CO雪橇，这可能表明恒星形成的发作更加集中。通过利用CO雪橇斜率来推断CO（1-0）过渡的亮度，并使用经典的转换因子对Alpha_co的主要序列星系= 3.8 m_sun（k km s^-1 pc^-2）^-1，我们发现这些星系非常丰富，与60％和80％的分子气体之间，我们发现这些星系非常丰富，并且很长。最后，我们获得了与恒星和气体质量总和（至少在五个星系中的四个）相提并论的动力质量，从而使我们能够在前所未有的红移对主序列星系的Alpha_co参数上对Alpha_co参数进行第一个约束。
We present the detection of CO(5-4) with S/N> 7 - 13 and a lower CO transition with S/N > 3 (CO(4-3) for 4 galaxies, and CO(3-2) for one) with ALMA in band 3 and 4 in five main sequence star-forming galaxies with stellar masses 3-6x10^10 M/M_sun at 3 < z < 3.5. We find a good correlation between the total far-infrared luminosity LFIR and the luminosity of the CO(5-4) transition L'CO(5-4), where L'CO(5-4) increases with SFR, indicating that CO(5-4) is a good tracer of the obscured SFR in these galaxies. The two galaxies that lie closer to the star-forming main sequence have CO SLED slopes that are comparable to other star-forming populations, such as local SMGs and BzK star-forming galaxies; the three objects with higher specific star formation rates (sSFR) have far steeper CO SLEDs, which possibly indicates a more concentrated episode of star formation. By exploiting the CO SLED slopes to extrapolate the luminosity of the CO(1-0) transition, and using a classical conversion factor for main sequence galaxies of alpha_CO = 3.8 M_sun(K km s^-1 pc^-2)^-1, we find that these galaxies are very gas rich, with molecular gas fractions between 60 and 80%, and quite long depletion times, between 0.2 and 1 Gyr. Finally, we obtain dynamical masses that are comparable with the sum of stellar and gas mass (at least for four out of five galaxies), allowing us to put a first constraint on the alpha_CO parameter for main sequence galaxies at an unprecedented redshift.
