Protostars and Planets VI, Heidelberg, July 15-20, 2013
Wavelet-based cross-correlation analysis of the scaling in molecular clouds
Arshakian, Tigran (Universität zu Köln)
Ossenkopf, Volker (Universität zu Köln)
We develop a wavelet-based cross-correlation (WCC)
method to study the correlation between structural
changes in molecular clouds as a function of scale. The
method compares a pair of maps observed in different
tracers or at different velocity ranges.
Advantages of the WCC method:
Allows to measure the correlation coefficient and
structural offset between two maps as a function of
Allows to weight individual pixels by their
Is robust against the noise.
Application of the WCC to simulated fBm (fractional
Brownian motion) maps reveals that:
Cross-correlation coefficient can strongly depend on
Correlation coefficient and offset can be recovered
robustly regardless of noise.
Analysis of the G333 molecular line maps (13CO and
A large scale gradient in the structural distribution.
This could indicate a density structure where every
core shows a low density tail towards the South-West
mainly seen in 13CO.
The WCC can be used to trace the correlated structural
changes between different maps of a molecular cloud
at scales representing the structural and physical
importance such as chemical and phase transitions.
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