[ITAL]HUBBLE SPACE TELESCOPE[/ITAL][ITAL]Hubble Space Telescope[/ITAL] Ultraviolet Spectral Energy Distributions for Three Ultraluminous Infrared Galaxies
[ITAL]HUBBLE SPACE TELESCOPE[/ITAL][ITAL]Hubble Space Telescope[/ITAL] Ultraviolet Spectral Energy Distributions for Three Ultraluminous Infrared Galaxies
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[ITAL]哈勃太空望远镜[/ITAL][ITAL]哈勃太空望远镜[/ITAL]三个超亮红外星系的紫外光谱能量分布
DOI：
10.1086/300831
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
D. Sanders
中科院分区：
文献类型：
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作者：
N. Trentham;J. Kormendy;D. Sanders
我们给出了从IRAS修正的明亮星系样本中挑选出的三个超发光红外星系(λ：L Ir&Gt；10 12 L⊙)的哈勃太空望远镜弱物相机紫外线(ULIGs=2300A，1400A)的图像。其目的是估计光谱能量分布(SED)，以便于在深光学、红外和亚毫米探测中识别高红移的类似物体。用F220W滤光片很好地探测到了三个星系：VII ZW 031(=IRAS F05081+7936)、IRAS F12112+0305和IRAS F22491-1808。其中两个是用F140W过滤器边缘检测到的。这些通量与地面光学和红外测光一起用于计算宽波长范围内的SED。测量的SED从光学下降到紫外线，但下降的幅度从IRASF22491-1808中的∼3倍到IIIZW031中的∼100倍。这很可能是由于不同的内部灭绝造成的。通过将VII ZW 031中测量到的光学内消光外推到紫外线波长，也提出了这样的解释。K校正的计算是为了确定样本星系在高红移时的颜色。像VIZW031这样的星系，其静止框架的紫外线通量非常低，这意味着这样的高红移星系在光学观测中将是极红的，甚至消失。另一方面，像IRAS F12112+0305和IRAS F22491-1808这样的星系，如果处于高红移，将是足够蓝的，以至于它们不容易与正常的场星系区分开来，因此被识别为ULIGs。这就意味着，亚毫米探测可能是正确识别大多数高红移ULIG的唯一手段。
We present Hubble Space Telescope Faint Object Camera ultraviolet (λ= 2300 Å, 1400 Å) images of three ultraluminous infrared galaxies (ULIGs: L ir> 10 12 L⊙) selected from the IRAS Revised Bright Galaxy Sample. The purpose is to estimate spectral energy distributions (SEDs) to facilitate the identification of similar objects at high redshift in deep optical, infrared, and submillimeter surveys. All three galaxies, VII Zw 031 (= IRAS F05081+ 7936), IRAS F12112+ 0305, and IRAS F22491-1808, were well detected with the F220W filter. Two of the three were marginally detected with the F140W filter. The fluxes, together with ground-based optical and infrared photometry, are used to compute SEDs over a wide wavelength range. The measured SEDs drop from the optical to the ultraviolet, but the magnitude of the drop ranges from a factor of∼ 3 in IRAS F22491-1808 to a factor of∼ 100 in VII Zw 031. This is most likely due to different internal extinctions. Such an interpretation is also suggested by extrapolating to ultraviolet wavelengths the optical internal extinction measured in VII Zw 031. K-corrections are calculated to determine the colors of the sample galaxies as seen at high redshifts. Galaxies such as VII Zw 031 have very low observed rest-frame UV fluxes, which means that such galaxies at high redshift will be extremely red or even missing in optical surveys. On the other hand, galaxies such as IRAS F12112+ 0305 and IRAS F22491-1808, if seen at high redshift, would be sufficiently blue that they would not easily be distinguished from normal field galaxies and therefore, identified as ULIGs. The implication is then that submillimeter surveys may be the only means of properly identifying the majority of ULIGs at high redshift.