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We investigate the uncertainties affecting the temperature profiles of dense cores of interstellar clouds. In regions shielded from external ultraviolet radiation, the problem is reduced to the balance between cosmic ray heating, line…

Astrophysics of Galaxies · Physics 2015-05-30 M. Juvela , N. Ysard

The physical conditions in a collapsing cloud can be traced by observations of molecular lines. To correctly interpret these observations the abundance distributions of the observed species need to be derived. The chemistry in a collapsing…

Solar and Stellar Astrophysics · Physics 2009-11-13 R. J. van Weeren , C. Brinch , M. R. Hogerheijde

In this study, we introduce a sensitivity analysis methodology for stochastic systems in chemistry, where dynamics are often governed by random processes. Our approach is based on gradient estimation via finite differences, averaging…

Quantitative Methods · Quantitative Biology 2026-01-12 Erika M. Herrera Machado , Jakob L. Andersen , Rolf Fagerberg , Daniel Merkle

We combine dynamical and non-equilibrium chemical modeling of evolving prestellar molecular cloud cores, and explore the evolution of molecular abundances in the contracting core. We model both magnetic cores, with varying degrees of…

Astrophysics of Galaxies · Physics 2015-06-03 Konstantinos Tassis , Karen Willacy , Harold W. Yorke , Neal J. Turner

The evolution of star-forming regions and their thermal balance are strongly influenced by their chemical composition, that, in turn, is determined by the physico-chemical processes that govern the transition between the gas phase and the…

In dynamic discrete choice models, some parameters, such as the discount factor, are being fixed instead of being estimated. This paper proposes two sensitivity analysis procedures for dynamic discrete choice models with respect to the…

Econometrics · Economics 2024-08-30 Chun Pong Lau

It is important to understand the origin of molecular line intensities and chemical composition in the molecular-cloud scale in the Galactic sources because it serves as a benchmark to compare with the chemical compositions of extragalactic…

Astrophysics of Galaxies · Physics 2019-02-13 Nanase Harada , Yuri Nishimura , Yoshimasa Watanabe , Satoshi Yamamoto , Yuri Aikawa , Nami Sakai , Takashi Shimonishi

Upcoming facilities such as the Herschel Space Observatory or ALMA will deliver a wealth of molecular line observations of young stellar objects (YSOs). Based on line fluxes, chemical abundances can then be estimated by radiative transfer…

Solar and Stellar Astrophysics · Physics 2009-07-22 Simon Bruderer , Steven D. Doty , Arnold O. Benz

The sensitivity parameter is widely used for quantifying fine tuning. However, examples show it fails to give correct results under certain circumstances. We argue that the problems of the sensitivity parameter are almost identical to the…

High Energy Physics - Phenomenology · Physics 2009-02-05 Su Yan

Reaction-diffusion models are widely used to study spatially-extended chemical reaction systems. In order to understand how the dynamics of a reaction-diffusion model are affected by changes in its input parameters, efficient methods for…

Quantitative Methods · Quantitative Biology 2017-03-08 Christopher Lester , Christian A. Yates , Ruth E. Baker

With the advent of large spectroscopic surveys the amount of high quality chemo-dynamical data in the Milky Way (MW) increased tremendously. Accurately and correctly capturing and explaining the detailed features in the high-quality…

A reliable estimate of the molecular gas content in galaxies plays a crucial role in determining their dynamical and star-forming properties. However, H2, the dominant molecular species, is difficult to observe directly, particularly in the…

Astrophysics · Physics 2008-11-26 T. A. Bell , E. Roueff , S. Viti , D. A. Williams

We analyze hydrodynamic simulations of turbulent, star-forming molecular clouds that are post-processed with the photo-dissociation region astrochemistry code 3D-PDR. We investigate the sensitivity of 15 commonly applied turbulence…

Astrophysics of Galaxies · Physics 2018-07-11 Ryan D. Boyden , Stella S. R. Offner , Eric W. Koch , Erik W. Rosolowsky

Advanced telescopes, such as ALMA and JWST, are likely to show that the chemical universe may be even more complex than currently observed, requiring astrochemical modelers to improve their models to account for the impact of new data.…

Astrophysics of Galaxies · Physics 2017-08-07 E M Penteado , C Walsh , H M Cuppen

We present an extensive comparison of models of structure formation with observations, based on linear and quasi-linear theory. We assume a critical matter density, and study both cold dark matter models and cold plus hot dark matter…

Astrophysics · Physics 2015-06-24 Andrew R Liddle , David H Lyth , R K Schaefer , Q Shafi , Pedro T P Viana

With the chemical reaction rate database UMIST95 (Millar et al. 1997) we analyze how uncertainties in rate constants of gas-phase chemical reactions influence the modelling of molecular abundances in the interstellar medium. Random…

Astrophysics · Physics 2009-11-10 A. I. Vasyunin , A. M. Sobolev , D. S. Wiebe , D. A. Semenov

We present a study of the elemental depletion in the interstellar medium. We combined the results of a Galatic model describing the gas physical conditions during the formation of dense cores with a full-gas-grain chemical model. During the…

Astrophysics of Galaxies · Physics 2020-07-29 V. Wakelam , W. Iqbal , J. -P. Melisse , P. Gratier , M. Ruaud , I. Bonnell

Chemical models have been developed over the years by astrophysicists to study the pro- cesses at play in the various environments of the interstellar medium (ISM) that define the chemical composition of the gas and the dust. These…

Astrophysics of Galaxies · Physics 2013-10-15 Marcelino Agundez , Valentine Wakelam

The paper deals with an empirical validation of a building thermal model. We put the emphasis on sensitivity analysis and on research of inputs/residual correlation to improve our model. In this article, we apply a sensitivity analysis…

Data Analysis, Statistics and Probability · Physics 2012-12-24 Thierry Alex Mara , Harry Boyer , François Garde

The recent advancements in mathematical modeling of biochemical systems have generated increased interest in sensitivity analysis methodologies. There are two primary approaches for analyzing these mathematical models: the stochastic…

Computation · Statistics 2025-10-14 Kannon Hossain , Roger Sidje , Fahad Mostafa