arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1209.4377astro-ph.CO
收藏

微弱的亚毫米星系计数在450微米

Faint Submillimter Galaxy Counts at 450 micron

Chian-Chou Chen, Lennox L. Cowie, Amy J. Barger, Caitlin M. Casey, Nicholas Lee, David B. Sanders, Wei-Hao Wang, Jonathan P. Williams

摘要:

我们提出的结果SCUBA 2观测在450微米和850微米的领域透镜的大规模集群A370。在450微米和850微米处,总测量面积> 100弧分2,1 σ灵敏度分别为3.92和0.82 mJy/束,我们找到了信噪比> 4的450微米处20个源和850微米处26个源的安全样本。利用最新的A370透镜模型和蒙特卡罗模拟,我们推导出在两个波长的计数。450微米的数字计数探测比最近从赫歇尔太空望远镜在类似波长下获得的计数深四倍,我们估计450微米的河外背景光(EBL)中有47-61%被分解为450微米通量大于4.5 mJy的单个源。在4西格玛样本中的微弱的450微米源具有3角秒的位置精度,而较亮的源(信噪比> 6西格玛)好到1.4角秒。利用深射电图(1 sigma ~ 6 μ Jy),我们发现具有安全射电对应物的亚毫米波源的百分比对于内禀通量> 6 mJy的450微米源为85%,对于内禀通量> 4 mJy的850微米源为67%。我们还发现,在850微米处检测到67%的> 4西格玛450微米源,而在450微米处的> 4西格玛850微米源的回收率为54%。结合使用毫米通量比估计的源红移,恢复率是一致的情况下,450微米和20厘米的排放优先选择较低的红移尘埃源,而850微米的排放痕迹较高分数的尘埃源在较高的红移。[阿布里奇]

英文摘要:

We present the results of SCUBA2 observations at 450 micron and 850 micron of the field lensed by the massive cluster A370. With a total survey area > 100 arcmin2 and 1 sigma sensitivities of 3.92 and 0.82 mJy/beam at 450 and 850 micron respectively, we find a secure sample of 20 sources at 450 micron and 26 sources at 850 micron with a signal-to-noise ratio > 4. Using the latest lensing model of A370 and Monte Carlo simulations, we derive the number counts at both wavelengths. The 450 micron number counts probe a factor of four deeper than the counts recently obtained from the Herschel Space Telescope at similar wavelengths, and we estimate that ~47-61% of the 450 micron extragalactic background light (EBL) resolved into individual sources with 450 micron fluxes greater than 4.5 mJy. The faint 450 micron sources in the 4 sigma sample have positional accuracies of 3 arcseconds, while brighter sources (signal-to-noise > 6 sigma) are good to 1.4 arcseconds. Using the deep radio map (1 sigma ~ 6 uJy) we find that the percentage of submillimeter sources having secure radio counterparts is 85% for 450 micron sources with intrinsic fluxes > 6 mJy and 67% for 850 micron sources with intrinsic fluxes > 4 mJy. We also find that 67% of the > 4 sigma 450 micron sources are detected at 850 micron, while the recovery rate at 450 micron of > 4 sigma 850 micron sources is 54%. Combined with the source redshifts estimated using millimetric flux ratios, the recovered rate is consistent with the scenario where both 450 micron and 20 cm emission preferentially select lower redshift dusty sources, while 850 micron emission traces a higher fraction of dusty sources at higher redshifts. [Abridge]

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。

↑