Abstract
Noise is a significant part within a millimeter-wave molecular line datacube. Analyzing the noise improves our understanding of noise characteristics, and further contributes to scientific discoveries. We measure the noise level of a single datacube from MWISP and perform statistical analyses. We identified major factors which increase the noise level of a single datacube, including bad channels, edge effects, baseline distortion and line contamination. Cleaning algorithms are applied to remove or reduce these noise components. As a result, we obtained the cleaned datacube in which noise follows a positively skewed normal distribution. We further analyzed the noise structure distribution of a 3D mosaicked datacube in the range
l
=
40
⋅
°
7
to
43
⋅
°
3
and
b
=
−
2
⋅
°
3
to
0
⋅
°
3
and found that noise in the final mosaicked datacube is mainly characterized by noise fluctuation among the cells.