Dust Absorption and the Ultraviolet Luminosity Density at z ≈ 3 as Calibrated by Local Starburst Galaxies
Dust Absorption and the Ultraviolet Luminosity Density at z ≈ 3 as Calibrated by Local Starburst Galaxies
复制标题
DOI：
10.1086/307523
复制
发表时间：
1999-03
期刊：
影响因子：
--
通讯作者：
G. Meurer;T. Heckman;D. Calzetti
中科院分区：
文献类型：
--
作者：
G. Meurer;T. Heckman;D. Calzetti
我们改进的技术来测量吸收校正的紫外（UV）光度的星爆星系单独使用静止帧UV量，并将其应用到莱曼极限U辍学在z 103发现在哈勃深场（HDF）。该方法基于观测到的远红外（FIR）与紫外线通量之比与光谱斜率β（紫外线颜色）之间的相关性。一个简单的拟合这个关系允许的紫外线通量吸收的灰尘和重新处理的FIR计算，从而确定无尘紫外线光度。利用国际紫外探测器光谱和红外天文卫星流量，对FFIR/F1600与β的关系进行了定标，并将其转换为A1600（尘埃在1600 nm处的吸收）和宽波段光度色。这两种校准几乎完全独立于理论恒星人口模型。我们表明，最近的边缘和nondetectors的HDF U辍学在无线电和亚毫米波波长是一致的，他们假设的星爆性质和我们计算的A1600。这也是正确的，最近的观测比的光发射线通量紫外线通量密度在最亮的U辍学。后一个比率被证明不是灰尘消失的良好指标。在U脱落的情况下，绝对星等M1600，0与β相关：较亮的星系更红，就像观测到的局部星暴星系一样。这表明在z = 3时，质量-金属丰度关系已经存在。U脱落的吸收校正紫外光度函数延伸到M1600，0 <$-24 AB mag，对应于星星形成速率~200 <$yr-1（H 0 = 50 km s-1 Mpc-3，q 0 = 0.5）。经吸收校正后的紫外光度密度为ρ 1600，0 ≥ 1.4 × 1027 ergs-1 Hz-1 Mpc-1。这仍然是一个下限，因为完整性修正还没有完成，因为只有A1600等的星系在紫外线下足够蓝，才能被选为U退出星系。在1600 ℃时，样品的平均吸尘因子为5.4 ± 0.9。
We refine a technique to measure the absorption-corrected ultraviolet (UV) luminosity of starburst galaxies using rest-frame UV quantities alone and apply it to Lyman-limit U dropouts at z ≈ 3 found in the Hubble Deep Field (HDF). The method is based on an observed correlation between the ratio of far-infrared (FIR) to UV fluxes with spectral slope β (a UV color). A simple fit to this relation allows the UV flux absorbed by dust and reprocessed to the FIR to be calculated, and hence the dust-free UV luminosity to be determined. International Ultraviolet Explorer spectra and Infrared Astronomical Satellite fluxes of local starbursts are used to calibrate the FFIR/F1600 versus β relation in terms of A1600 (the dust absorption at 1600 Å) and the transformation from broadband photometric color to β. Both calibrations are almost completely independent of theoretical stellar-population models. We show that the recent marginal and nondetections of HDF U dropouts at radio and submillimeter wavelengths are consistent with their assumed starburst nature and our calculated A1600. This is also true of recent observations of the ratio of optical emission-line flux to UV flux density in the brightest U dropouts. This latter ratio turns out not to be a good indicator of dust extinction. In U dropouts, absolute magnitude M1600,0 correlates with β: brighter galaxies are redder, as is observed to be the case for local starburst galaxies. This suggests that a mass-metallicity relationship is already in place at z ≈ 3. The absorption-corrected UV luminosity function of U dropouts extends up to M1600,0 ≈ -24 AB mag, corresponding to a star formation rate ~200 ℳ☉ yr-1 (H0 = 50 km s-1 Mpc-3 and q0 = 0.5 are assumed throughout). The absorption-corrected UV luminosity density at z ≈ 3 is ρ1600,0 ≥ 1.4 × 1027 ergs-1 Hz-1 Mpc-1. It is still a lower limit since completeness corrections have not been done and because only galaxies with A1600 ≲ 3.6 mag are blue enough in the UV to be selected as U dropouts. The luminosity-weighted mean dust-absorption factor of our sample is 5.4 ± 0.9 at 1600 Å.