Cosmic star-formation history from a non-parametric inversion of infrared galaxy counts
Cosmic star-formation history from a non-parametric inversion of infrared galaxy counts
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来自红外星系计数非参数反演的宇宙恒星形成历史
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发表时间：
2009
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通讯作者：
H Germany
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作者：
D. L. Borgne;D. Elbaz;P. Ocvirk;Christophe Pichon CEASaclay;DSMIRFUSAp;Gif;France.;I. Paris;UMR7095;Upmc;París;A. Potsdam;Potsdam;H Germany
目标。本文旨在通过对近期中、远红外观测数据的经验模拟，为宇宙恒星形成历史提供新的保守约束。方法：研究方法。提出了一种新的基于非参数反演技术的经验方法。它主要使用多波长星系计数在红外和亚毫米(15，24，70,160,850μm)，它不需要任何红移信息。这种反演可以被认为是对星系红外光度函数的所有可能的演化和形状的“盲目”搜索，由此推导出恒星形成率密度(SFRD)的演化及其不确定性。宇宙红外背景(CIRB)测量被用来在事后缩小解决方案的范围。这种反演只依赖于两个假设：(1)光度函数在红移和光度上都保持平滑；(2)必须假定星系的一组红外光谱能量分布(SED)，且仅依赖于总光度。结果。在低红移时恢复的SF历史范围受到很好的约束，并与各种红移测量的直接测量结果一致。红移分布被恢复，而不需要对进行计数的源的红移进行任何输入。SFRD的峰值在$zsimeq 2$是首选的，尽管不排除更高的红移。我们还证明，在上述假设下，160mJy的星系计数存在约20mJy的过剩，这与其他波长的星系计数不一致。最后，我们发现观测到的恒星质量密度的演化与我们的SF历史模型的预测有很好的一致性。结论。仅用依赖光度的SED数据库解释的多波长计数和CIRB(两个投影观测)就包含了足够的信息，可以恢复星系红外光度函数的宇宙演化，从而恢复SFRD的演化，具有可量化的误差。此外，反演无法完美地同时模拟多波长红外计数意味着：(1)较冷星系的子群的存在；(2)尘埃温度在本星系中的分散程度比预期的更大；(3)星系的红外SED的红移演化。
Aims. This paper aims at providing new conservative constraints on the cosmic star-formation (SF) history from the empirical modeling of recent observations in the mid and far infrared. Methods. We present a new empirical method based on a non-parametric inversion technique. It primarily uses multi-wavelength galaxy counts in the infrared and sub-mm (15, 24, 70, 160, 850 μ m), and it does not require any redshift information. This inversion can be considered as a “blind” search for all possible evolutions and shapes of the infrared luminosity function of galaxies, from which the evolution of the star-formation rate density (SFRD) and its uncertainties are derived. The cosmic infrared background (CIRB) measurements are used a posteriori to tighten the range of solutions. The inversion relies only on two hypotheses: (1) the luminosity function remains smooth both in redshift and luminosity; (2) a set of infrared spectral energy distributions (SEDs) of galaxies must be assumed, with a dependency on the total luminosity alone. Results. The range of SF histories recovered at low redshift is well-constrained and consistent with direct measurements from various redshift surveys. Redshift distributions are recovered without any input into the redshifts of the sources making the counts. A peak of the SFRD at $zsimeq 2$ is preferred, although higher redshifts are not excluded. We also demonstrate that galaxy counts at 160 μ m present an excess around 20 mJy that is not consistent with counts at other wavelengths under the hypotheses cited above. Finally, we find good consistency between the observed evolution of the stellar mass density and the prediction from our model of SF history. Conclusions. Multi-wavelength counts and CIRB (both projected observations) alone, interpreted with a luminosity-dependent library of SEDs, contain enough information to recover the cosmic evolution of the infrared luminosity function of galaxies, and therefore the evolution of the SFRD, with quantifiable errors. Moreover, the inability of the inversion to model perfectly and simultaneously the multi-wavelength infrared counts implies either (i) the existence of a sub-population of colder galaxies; (ii) a larger dispersion of dust temperatures among local galaxies than expected; (iii) a redshift evolution of the infrared SED of galaxies.