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We propose a multi-component model for the observed diffuse neutrino flux, including the residual atmospheric backgrounds, a Galactic contribution (such as from cosmic ray interactions with gas), an extra-galactic contribution from pp…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Andrea Palladino , Walter Winter

We present a study of small carbon chains and rings in Photon Dominated Regions (PDRs) performed at millimetre wavelengths. Our sample consists of the Horsehead nebula (B33), the rho,Oph L1688 cloud interface, and the cometary-shaped cloud…

Astrophysics · Physics 2009-11-10 D. Teyssier , D. Fosse , M. Gerin , J. Pety , A. Abergel , E. Roueff

Generalized parton distributions (GPDs) have become a standard QCD tool for analyzing and parametrizing the non perturbative parton structure of hadron targets. GPDs might be viewed as non-diagonal overlaps of light-cone wave functions and…

High Energy Physics - Phenomenology · Physics 2009-02-19 B. Pasquini , S. Boffi

Aims. We model a diffuse molecular cloud present along the line of sight to the star HD 102065. We compare our modeling with observations to test our understanding of physical conditions and chemistry in diffuse molecular clouds. Methods.…

The radiation from stars and active galactic nuclei (AGN) creates photodissociation regions (PDRs) and X-ray dominated regions (XDRs), where the chemistry or heating are dominated by far-ultraviolet (FUV) radiation or X-ray radiation,…

Astrophysics of Galaxies · Physics 2022-09-28 Mark G. Wolfire , Livia Vallini , Mélanie Chevance

We investigate the physical conditions of the gas, atomic and molecular, in the filaments in the context of Photo-Dissociation Regions (PDRs) using the KOSMA-PDR mode of clumpy clouds. We also compare the [CII] vs. [NII] integrated…

Astrophysics of Galaxies · Physics 2017-02-22 P. García , M. Röllig , N. Abel , M. Steinke , M. Burton , R. Blackwell

We have carried out an in-depth study of the peripheral region of the molecular cloud L1204/S140, where the far ultraviolet radiation and the density are relatively low. Our observations test theories of photon-dominated regions (PDRs) in a…

Astrophysics · Physics 2009-11-07 Wenbin Li , Neal J. Evans , Daniel T. Jaffe , Ewine F. van Dishoeck , Wing-Fai Thi

Context. Carbonaceous nano-grains play a fundamental role in the physico-chemistry of the interstellar medium (ISM) and especially of photon-dominated regions (PDRs). Their properties vary with the local physical conditions and affect the…

Astrophysics of Galaxies · Physics 2022-10-05 T. Schirmer , N. Ysard , E. Habart , A. P. Jones , A. Abergel , L. Verstraete

A photon dominated region (PDR) is one of the leading candidate mechanisms for the origin of the warm CO gas with near universal $\sim$300~K rotational temperature inferred from the CO emission detected towards embedded protostars by…

Astrophysics of Galaxies · Physics 2015-06-22 Seokho Lee , Jeong-Eun Lee , Edwin A. Bergin , Yong-Sun Park

In bright photodissociation regions (PDRs) associated to massive star formation, the presence of dense "clumps" that are immersed in a less dense interclump medium is often proposed to explain the difficulty of models to account for the…

Nearby Photo-Dissociation Regions (PDRs), where the gas and dust are heated by the far UV-irradiation emitted from stars, are ideal templates to study the main stellar feedback processes. With this study we aim to probe the detailed…

The study of photoionised gas in planetary nebulae (PNe) has played a major role in the achievement, over the years, of a better understanding of a number of physical processes, pertinent to a broader range of fields than that of PNe…

Astrophysics · Physics 2009-11-13 Barbara Ercolano

We briefly describe the current version of the PHOENIX code. We then present some illustrative results from the modeling of Type Ia and Type II supernovae, hot stars, and irradiated giant planets. Good fits to observations can be obtained,…

Results from a large, multi-J CO, {13}CO, and HCN line survey of Luminous Infrared Galaxies (L_{IR}>=10^{10} L_{\odot}) in the local Universe (z<=0.1), complemented by CO J=4--3 up to J=13--12 observations from the Herschel Space…

We have constructed three-dimensional models for the equilibrium abundance of molecular hydrogen within diffuse interstellar clouds of arbitrary geometry that are illuminated by ultraviolet radiation. The position-dependent photo-…

Astrophysics · Physics 2009-10-30 Marco Spaans , David A. Neufeld

NEMO.2003 (vienna NEw MOdel grid of stellar atmospheres) is a DVD with 91,520 stellar model atmospheres representing a 5D grid of modified ATLAS9 atmospheres; the purpose of the modifications was to include different treatments of…

Astrophysics · Physics 2007-05-23 J. Nendwich , U. Heiter , F. Kupka , N. Nesvacil , W. W. Weiss

Computational astrochemical models are essential for helping us interpret and understand the observations of different astrophysical environments. In the age of high-resolution telescopes such as JWST and ALMA, the substructure of many…

Astrophysics of Galaxies · Physics 2025-06-18 Gijs Vermariën , Thomas G. Bisbas , Serena Viti , Yue Zhao , Xuefei Tang , Rahul Ravichandran

The Orion Bar is one of the nearest and best-studied photodissociation or photon-dominated regions (PDRs). Observations reveal the presence of H2 lines from vibrationally or rotationally excited upper levels that suggest warm gas…

Astrophysics of Galaxies · Physics 2009-08-05 Gargi Shaw , G. J. Ferland , W. J. Henney , P. C. Stancil , N. P. Abel , E. W. Pellegrini , J. A. Baldwin , P. A. M. van Hoof

Molecular line observations may serve as diagnostics of the degree to which the number density of cosmic ray protons, having energies of 10s to 100s of MeVs each, is enhanced in starburst galaxies and galaxies with active nuclei. Results,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 E. Bayet , D. A. William , T. W. Hartquist , S. Viti

Blazar hadronic models have been developed in the past decades as an alternative to leptonic ones. In hadronic models the gamma-ray emission is associated with synchrotron emission by protons, and/or secondary leptons produced in…