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Related papers: Photon Dominated Region Modeling of Barnard 68

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We observationally investigate the relation between the photoelectric heating efficiency in PDRs and the charge of PAHs, which are considered to play a key role in photoelectric heating. Using PACS onboard Herschel, we observed six PDRs…

Based on theoretical spectra computed using Density Functional Theory we study the properties of Polycyclic Aromatic Hydrocarbons (PAH). In particular using bin-average spectra of PAH molecules with varying number of carbons we investigate…

We reanalyze the mid-infrared (5-40 $\mu$m) Spitzer spectra of 86 low-redshift ($z < 0.5$) Palomar-Green quasars to investigate the nature of polycyclic aromatic hydrocarbon (PAH) emission and its utility as a star formation rate (SFR)…

Astrophysics of Galaxies · Physics 2022-02-16 Yanxia Xie , Luis C. Ho

Various studies have emphasized variations of the charge state and composition of the interstellar polycyclic aromatic hydrocarbon (PAH) population in photodissociation regions (PDRs). We aim to model the spatial evolution of the charge and…

Astrophysics of Galaxies · Physics 2015-06-12 J. Montillaud , C. Joblin , D. Toublanc

The interaction of polycyclic aromatic hydrocarbons (PAHs) with vacuum ultraviolet (VUV) photons triggers the emission of the well-known aromatic infrared bands (AIBs) but other mechanisms such as fragmentation can be involved in this…

Astrophysics of Galaxies · Physics 2021-08-12 Alexandre Marciniak , Christine Joblin , Giacomo Mulas , Venkat Rao Mundlapati , Anthony Bonnamy

Several galaxies, such as dwarfs and Irregulars as well as outer galactic clouds have low metallicity. At low metallicities a reduction in the amount of dust and heavy elements plays a significant role on the chemistry as well as the…

Astrophysics · Physics 2007-05-23 S. Jeyakumar , J. Stutzki

Photon Dominated Regions (PDRs) are interfaces between the mainly ionized and mainly molecular material around young massive stars. Analysis of the physical and chemical structure of such regions traces the impact of far-ultraviolet…

Astrophysics of Galaxies · Physics 2017-02-22 Z. Nagy , Y. Choi , V. Ossenkopf-Okada , F. F. S. van der Tak , E. A. Bergin , M. Gerin , C. Joblin , M. Roellig , R. Simon , J. Stutzki

Infrared emission from polycyclic aromatic hydrocarbons (PAHs) play a major role in determining the charge balance of their host environments that include photo-dissociation regions (PDRs) in galaxies, planetary nebulae, and rims of…

We have made one-dimensional raster-scan observations of the rho Oph and sigma Sco star-forming regions with two spectrometers (SWS and LWS) on board the ISO. In the rho Oph region, [SiII] 35um, [OI] 63um, 146um, [CII] 158um, and the H2…

Astrophysics · Physics 2009-11-13 Yoko Okada , Takashi Onaka , Takao Nakagawa , Hiroshi Shibai , Daigo Tomono , Yukari Y. Yui

We observed H2 line emission with Spitzer-IRS toward M17-SW and modeled the data with our PDR code. Derived gas density values of up to few times 10^7 cm^-3 indicate that H2 emission originates in high-density clumps. We discover that the…

Astrophysics of Galaxies · Physics 2013-09-13 Yaron Sheffer , Mark G. Wolfire

Low-resolution, mid-infrared Spitzer/IRS spectral maps are presented for three nearby, low-metallicity dwarf galaxies (NGC 55, NGC 3109 and IC 5152) for the purpose of examining the spatial distribution and variation of polycyclic aromatic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Korey Haynes , John M. Cannon , Evan D. Skillman , Dale C. Jackson , Robert D. Gehrz

We present spectroscopic observations obtained with the infrared Spitzer Space Telescope, which provide insight into the H$_2$ physics and gas energetics in photodissociation Regions (PDRs) of low to moderate far-ultraviolet (FUV) fields…

We decompose the observed 7.7 $\mu$m polycyclic aromatic hydrocarbon (PAH) emission complexes in a large sample of over 7000 mid-infrared spectra of the interstellar medium (ISM) using spectral cubes observed with the Spitzer/IRS-SL…

Astrophysics of Galaxies · Physics 2017-03-22 D. J. Stock , E. Peeters

We present subarcsecond-resolution ALMA mosaics of the Orion Bar PDR in [CI] 609um, C2H (4-3), and C18O (3-2) emission lines complemented by JWST images of H2 and aromatic infrared band (AIB) emission. The rim of the Bar shows very…

We investigate the mid-infrared (IR) emission in the Orion Bar photodissociation region, using archival photometric and spectroscopic observations from UKIRT, Spitzer, ISO, and SOFIA telescopes. Specifically, we consider flux densities of…

Astrophysics of Galaxies · Physics 2021-11-11 Maria S. Murga , Maria S. Kirsanova , Dmitry S. Wiebe , Paul A. Boley

We combine the galaxy formation model GALFORM with the Photon Dominated Region code UCL_PDR to study the emission from the rotational transitions of 12CO (CO) in galaxies from z=0 to z=6 in the Lambda CDM framework. GALFORM is used to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Claudia del P. Lagos , Estelle Bayet , Carlton M. Baugh , Cedric G. Lacey , Tom Bell , Nikolaos Fanidakis , James Geach

We present observations of 13CO, C18O, HCO+, H13CO+, DCO+ and N2H+ line emission towards the Barnard 68 starless core. The line profiles are interpreted using a chemical network coupled with a radiative transfer code in order to reconstruct…

Astrophysics · Physics 2009-11-13 Sébastien Maret , Edwin A. Bergin , Charles J. Lada

We present new Herschel-SPIRE imaging spectroscopy (194-671 microns) of the bright starburst galaxy M82. Covering the CO ladder from J=4-3 to J=13-12, spectra were obtained at multiple positions for a fully sampled ~ 3 x 3 arcminute map,…

Infrared emission features at 3.3, 6.2, 7.7, 8.6, and 11.2 $\mu$m, attributed to polycyclic aromatic hydrocarbons, show variations in relative intensity, shape, and peak position. These variations depend on the physical conditions of the…

Astrophysics of Galaxies · Physics 2021-11-24 C. Knight , E. Peeters , M. Wolfire , D. J. Stock