arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0812.0358astro-ph
收藏

利用Ia型超新星进行大型快速成像巡天以限制暗能量

Utilizing Type Ia Supernovae in a Large, Fast, Imaging Survey to Constrain Dark Energy

Andrew R. Zentner, Suman Bhattacharya

摘要:

我们研究了一个大样本的Ia型超新星,可能会被观察到的成像调查,迅速扫描了大部分的天空约束暗能量的效用。我们考虑的信息,从传统的光度距离测试,以及在SNeIa通量在固定的红移引起的引力透镜的传播。在我们的分析中,我们包括测光红移的不确定性的治疗。我们的主要结果是,包含在SNeIa的平均距离模量和SNeIa距离模量之间的色散的信息互补,打破了目前的暗能量状态方程和它的时间变化之间的简并性,而不需要一个高红移超新星样本。为了解决光度红移的不确定性,我们提出了暗能量的限制作为一个功能的一组外部的光谱观测SNeIa,可用于红移校准,nspec的大小。我们发现,成像调查可以约束的暗能量状态方程的时代,它是最好的约束与1西格玛误差σ(wpiv)~0.03-0.09$,取决于各种假设。此外,一旦nspec ~ 10^3,光谱校准样本增加所带来的误差σ(wpiv)的边际改善就会下降。这一结果很重要,因为它是在未来十年可能被编译的校准样本的大小的顺序,因为,对于这种大小的样本,光谱和成像调查分别放置在暗能量状态方程的可比约束。在所有情况下,最好用一组光谱观测到的SNeIa来校准光度红移,这些SNeIa具有比成像SNeIa的母样本相对更多的高红移物体。

英文摘要:

We study the utility of a large sample of type Ia supernovae that might be observed in an imaging survey that rapidly scans a large fraction of the sky for constraining dark energy. We consider information from the traditional luminosity distance test as well as the spread in SNeIa fluxes at fixed redshift induced by gravitational lensing. We include a treatment of photometric redshift uncertainties in our analysis. Our primary result is that the information contained in the mean distance moduli of SNeIa and the dispersion among SNeIa distance moduli complement each other, breaking a degeneracy between the present dark energy equation of state and its time variation without the need for a high-redshift supernova sample. To address photometric redshift uncertainties, we present dark energy constraints as a function of the size of an external set of spectroscopically-observed SNeIa that may be used for redshift calibration, nspec. We find that an imaging survey can constrain the dark energy equation of state at the epoch where it is best constrained with a 1-sigma error of sigma(wpiv)~0.03-0.09$, depending upon various assumptions. In addition, the marginal improvement in the error sigma(wpiv) from an increase in the spectroscopic calibration sample drops once nspec ~ 10^3. This result is important because it is of the order of the size of calibration samples likely to be compiled in the coming decade and because, for samples of this size, the spectroscopic and imaging surveys individually place comparable constraints on the dark energy equation of state. In all cases, it is best to calibrate photometric redshifts with a set of spectroscopically-observed SNeIa with relatively more objects at high redshift than the parent sample of imaging SNeIa.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑