A multiwavelength consensus on the main sequence of star-forming galaxies at z ~ 2
A multiwavelength consensus on the main sequence of star-forming galaxies at z ~ 2
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DOI：
10.1093/mnras/stu1110
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发表时间：
2014-06
影响因子：
4.8
通讯作者：
G. Rodighiero;A. Renzini;E. Daddi;I. Baronchelli;S. Berta;G. Cresci;A. Franceschini;C. Gruppioni;D. Lutz;C. Mancini;P. Santini;G. Zamorani;J. Silverman;D. Kashino;P. Andreani;A. Cimatti;H. Sánchez;E. L. Floch;B. Magnelli;P. Popesso;F. Pozzi
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作者：
G. Rodighiero;A. Renzini;E. Daddi;I. Baronchelli;S. Berta;G. Cresci;A. Franceschini;C. Gruppioni;D. Lutz;C. Mancini;P. Santini;G. Zamorani;J. Silverman;D. Kashino;P. Andreani;A. Cimatti;H. Sánchez;E. L. Floch;B. Magnelli;P. Popesso;F. Pozzi
我们比较了 COSMOS 场中 1.4 < z < 2.5 的恒星形成星系的各种恒星形成率 (SFR) 指标。对于根据 BzK 标准选择的星系，主要关注的是来自远红外（PACS-赫歇尔数据）的恒星形成率和来自紫外线的恒星形成率。与从 UV 测量的占主导地位的主序群相比，FIR 选择的样本导致 SFR 恒星质量 (M*) 关系的斜率截然不同，因为 FIR 选择主要仅选择少数异常值。然而，当在 PACS 地图上叠加 BzK 选择的星系时，用两个 SFR 指标得出的主序列之间存在总体一致性。由此产生的 SFR-M* 关系的对数斜率约为 0.8 − 0.9，与灰尘校正的紫外光度得出的结果一致。利用更深层的 24μm 斯皮策数据，我们对红化和恒星形成率约束较差的星系子样本进行了表征，因为它们在 B 波段非常微弱。赫歇尔和斯皮策数据的结合使我们能够在很大程度上打破这些有趣来源的年龄/红化简并性，通过区分一个星系在 B-z 中是否非常红色是因为尘埃严重变红，或者是否因为恒星形成已经（或正在）熄灭。最后，我们将我们的恒星形成率（UV）与通过叠加无线电数据得出的恒星形成率以及从 1.4 < z < 1.7 处恒星形成星系样本的 Hα 光度得出的恒星形成率进行了比较。两组 SFR 大致一致，因为它们与源自 UV 并通过叠加不同质量箱中相应 PACS 数据得出的 SFR 一致。
We compare various star formation rate (SFR) indicators for star-forming galaxies at 1.4 < z < 2.5 in the COSMOS field. The main focus is on the SFRs from the far-IR (PACS-Herschel data) with those from the ultraviolet, for galaxies selected according to the BzK criterion. FIR-selected samples lead to a vastly different slope of the SFRstellar mass (M∗) relation, compared to that of the dominant main sequence population as measured from the UV, since the FIR selection picks predominantly only a minority of outliers. However, there is overall agreement between the main sequences derived with the two SFR indicators, when stacking on the PACS maps the BzK-selected galaxies. The resulting logarithmic slope of the SFR-M∗ relation is ∼ 0.8 − 0.9, in agreement with that derived from the dust-corrected UV-luminosity. Exploiting deeper 24µm-Spitzer data we have characterized a sub-sample of galaxies with reddening and SFRs poorly constrained, as they are very faint in the B band. The combination of Herschel with Spitzer data have allowed us to largely break the age/reddening degeneracy for these intriguing sources, by distinguishing whether a galaxy is very red in B-z because of being heavily dust reddened, or whether because star formation has been (or is being) quenched. Finally, we have compared our SFR(UV) to the SFRs derived by stacking the radio data and to those derived from the Hα luminosity of a sample of star-forming galaxies at 1.4 < z < 1.7. The two sets of SFRs are broadly consistent as they are with the SFRs derived from the UV and by stackin the corresponding PACS data in various mass bins.