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In previous studies we identified two classes of starless cores, thermally subcritical and supercritical, distinguished by different dynamical behavior and internal structure. Here we study the evolution of the dynamically-unstable,…

Astrophysics of Galaxies · Physics 2015-05-13 Eric Keto , Paola Caselli

Stars form in cold dense cores showing subsonic velocity dispersions. The parental molecular clouds display higher temperatures and supersonic velocity dispersions. The transition from core to cloud has been observed in velocity dispersion,…

One of the longstanding issues in numerical relativity is to enable a simulation taking account of microphysical processes (e.g., weak interactions and neutrino cooling). We develop an approximate and explicit scheme in the fully general…

High Energy Astrophysical Phenomena · Physics 2010-12-09 Yuichiro Sekiguchi

We present a fully sampled map covering the Orion Hot Core and dense molecular ridge, in the sub-millimeter J=6-5 rotational transition of 13CO, at 0.45 mm with a resolution of 13 arcsec and 0.5 km s^-1. The map covers 3 arc min by 2arc min…

Solar and Stellar Astrophysics · Physics 2015-05-20 T. L. Wilson , D. Muders , M. Dumke , C. Henkel , Jonathan H. Kawamura

Isotopologue line intensity ratios of circumstellar molecules have been widely used to trace the photospheric elemental isotopic ratios of evolved stars. However, depending on the molecular species and the physical conditions of the…

Solar and Stellar Astrophysics · Physics 2020-07-01 M. Saberi , H. Olofsson , W. H. T. Vlemmings , E. De Beck , T. Khouri , S. Ramstedt

The improvement in observational facilities requires refining the modelling of the geometrical structures of astrophysical objects. Nevertheless, for complex problems such as line overlap in molecules showing hyperfine structure, a detailed…

Astrophysics · Physics 2015-03-13 F. Daniel , J. Cernicharo

In light of its ubiquitous presence in the interstellar gas, the chemistry and reactivity of the HCO+ ion requires special attention. The availability of up-to-date collisional data between this ion and the most abundant perturbing species…

Astrophysics of Galaxies · Physics 2022-01-13 F. Tonolo , L. Bizzocchi , M. Melosso , F. Lique , L. Dore , V. Barone , C. Puzzarini

The gravitational lens toward B0218+357 offers the unique possibility to study cool moderately dense gas with high sensitivity and angular resolution in a cloud that existed half a Hubble time ago. Observations of the radio continuum and…

Astrophysics · Physics 2009-11-13 N. Jethava , C. Henkel , K. M. Menten , C. L. Carilli , M. J. Reid

Aims: Accretion rates in low-mass protostars can be highly variable in time. Each accretion burst is accompanied by a temporary increase in luminosity, heating up the circumstellar envelope and altering the chemical composition of the gas…

Solar and Stellar Astrophysics · Physics 2015-05-13 Ruud Visser , Edwin A. Bergin , Jes K. Jorgensen

Spectral molecular line profile observations of star-forming molecular clouds sometimes show distinct red asymmetric double-peaked molecular line profiles with weaker blue peaks and stronger red peaks. For some star-forming molecular…

Solar and Stellar Astrophysics · Physics 2015-05-14 Yang Gao , Yu-Qing Lou

We use 3D-PDR, a three-dimensional astrochemistry code for modeling photodissociation regions (PDRs), to post-process hydrodynamic simulations of turbulent, star-forming clouds. We focus on the transition from atomic to molecular gas, with…

Solar and Stellar Astrophysics · Physics 2015-06-15 Stella S. R. Offner , Thomas G. Bisbas , Serena Viti , Thomas A. Bell

ALMA cycle 3 observations of $^{12}$CO $ J = 3\rightarrow2$, $^{13}$CO $J = 4\rightarrow 3$, SiO J = $8 \rightarrow 7$, and HCN J = $ 5 \rightarrow 4$ are presented. Significant extended emission is detected in $^{12}$CO J $ =…

Astrophysics of Galaxies · Physics 2020-06-17 Jordan Wheeler , Jason Glenn , Naseem Rangwala , Adalyn Fyhrie

We present a largely improved version of CRASH, a 3-D radiative transfer code that treats the effects of ionizing radiation propagating through a given inhomogeneous H/He cosmological density field, on the physical conditions of the gas.…

Astrophysics · Physics 2009-11-10 A. Maselli , A. Ferrara , B. Ciardi

Context: Knowledge about hot, massive stars is usually inferred from quantitative spectroscopy. To analyse non-spherical phenomena, the existing 1D codes must be extended to higher dimensions, and corresponding tools need to be developed.…

Solar and Stellar Astrophysics · Physics 2019-12-25 L. Hennicker , J. Puls , N. D. Kee , J. O. Sundqvist

We introduce the radiative transfer postprocessing code Subsweep. The code is based on the method of transport sweeps, in which the exact solution to the scattering-less radiative transfer equation is computed in a single pass through the…

Instrumentation and Methods for Astrophysics · Physics 2024-12-03 Toni Peter , Joseph S. W. Lewis , Ralf S. Klessen , Simon C. O. Glover , Guido Kanschat

Thermodynamic critical field curves have been measured for $La_{2-x}Sr_{x}CuO_{4+\delta}$ over the full range of carrier concentrations where superconductivity occurs in order to determine changes in the normal state density of states with…

Superconductivity · Physics 2016-08-31 Yung M. Huh , D. K. Finnemore

We analyse synthetic $^{12}$CO, $^{13}$CO, and [CII] emission maps of simulated molecular clouds of the SILCC-Zoom project, which include an on-the-fly evolution of H$_2$, CO, and C$^+$. We use simulations of hydrodynamical and…

Astrophysics of Galaxies · Physics 2022-07-12 S. Ebagezio , D. Seifried , S. Walch , P. C. Nürnberger , T. E. Rathjen , T. Naab

We introduce a non-exponential radiative framework that takes into account the local spatial correlation of scattering particles in a medium. Most previous works in graphics have ignored this, assuming uncorrelated media with a uniform,…

Graphics · Computer Science 2018-05-14 Adrian Jarabo , Carlos Aliaga , Diego Gutierrez

Resonance spectral lines such as H I Ly {\alpha}, Mg II h&k, and Ca II H&K that form in the solar chromosphere are influenced by the effects of 3D radiative transfer as well as partial redistribution (PRD). So far no one has modeled these…

Solar and Stellar Astrophysics · Physics 2016-12-28 Andrii V. Sukhorukov , Jorrit Leenaarts

We describe a code designed for hot media {(T $\ge$} a few 10$^4$ K), optically thick to Compton scattering. It computes the structure of a plane-parallel slab of gas in thermal and ionization equilibrium, illuminated on one or on both…

Astrophysics · Physics 2007-05-23 A. -M. Dumont , A. Abrassart , S. Collin