Observations of Diffuse Ultraviolet Emission from Draco
msra(2010)
摘要
We have studied small scale (2 arcmin) spatial variation of the diffuse UV
radiation using a set of 11 GALEX deep observations in the constellation of
Draco. We find a good correlation between the observed UV background and the IR
100 micron flux, indicating that the dominant contributor of the diffuse
background in the field is the scattered starlight from the interstellar dust
grains. We also find strong evidence of additional emission in the FUV band
which is absent in the NUV band. This is most likely due to Lyman band emission
from molecular hydrogen in a ridge of dust running through the field and to
line emissions from species such as C IV (1550 A) and Si II (1533 A) in the
rest of the field. A strong correlation exists between the FUV/NUV ratio and
the FUV intensity in the excess emission regions in the FUV band irrespective
of the optical depth of the region. The optical depth increases more rapidly in
the UV than the IR and we find that the UV/IR ratio drops off exponentially
with increasing IR due to saturation effects in the UV. Using the positional
details of Spitzer extragalactic objects, we find that the contribution of
extragalactic light in the diffuse NUV background is 49 +/- 13 photon units and
is 30 +/- 10 photon units in the FUV band.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要