Quantification of molecular cloud structure using theΔ-variance
نویسندگان
چکیده
منابع مشابه
Quantification of Variance Error
This paper accurately quantifies the way in which noise induced estimation errors are dependent on model structure, underlying system frequency response, measurement noise and input excitation. This exposes several new principles. In particular, it is shown here that when employing Output–Error model structures in a prediction-error framework, then the ensuing estimate variability in the freque...
متن کاملProbing the Evolution of Molecular Cloud Structure
We have derived large-scale dust column density maps for a complete set of nearby molecular clouds using a near-infrared extinction mapping technique. With these data, we performed the first systematic study of column density probability distributions in molecular clouds. We found that the probability density functions (PDFs) of non-star-forming clouds are almost always well-fitted by lognormal...
متن کاملThe Structure of Cold Molecular Cloud Cores
A brief summary is presented of our current knowledge of the structure of cold molecular cloud cores that do not contain proto-stars, sometimes known as starless cores. The most centrally condensed starless cores are known as pre-stellar cores. These cores probably represent observationally the initial conditions for protostellar collapse that must be input into all models of star formation. Th...
متن کاملAccurate Quantification of Variance Error
This paper accurately quantifies the way in which noise induced estimation errors are dependent on model structure, underlying system frequency response, measurement noise and input excitation. This exposes several new principles. In particular, it is shown here that when employing Output–Error model structures in a prediction-error framework, then the ensuing estimate variability in the freque...
متن کاملExact Quantification of Variance Error
Abstract: This paper establishes a method for quantifying variance error in cases where the input spectral density has a rational factorisation. Compared to previous work which has involved asymptotic-in-model-order techniques and yielded expressions which are only approximate for finite orders, the quantifications provided here are exact for finite model order, although they still only apply a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2001
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20000292