Conclusions

Péquignot, Stéphane

doi:10.1484/m.mom-eb.5.100973

Cited by 7 publications

(10 citation statements)

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“…Rates from both of these sources were fitted to analytic expressions as a function of temperature by Draine (2011, Appendix F) 10 . Péquignot (1990) computed rate constants for k j,j (H + , T ) from the cross sections of Chambaud et al (1980) and…”

Section: Appendixmentioning

confidence: 99%

Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443

Ritchey,

Jenkins,

Federman

et al. 2020

Preprint

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We present the results of a detailed investigation into the physical conditions in interstellar material interacting with the supernova remnant IC 443. Our analysis is based on a comprehensive examination of high-resolution far-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope of two stars behind IC 443. One of our targets (HD 43582) probes gas along the entire line of sight through the supernova remnant, while the other (HD 254755) samples material located ahead of the primary supernova shock front. We identify low velocity quiescent gas in both directions and find that the densities and temperatures in these components are typical of diffuse atomic and molecular clouds. Numerous high velocity components are observed in the absorption profiles of neutral and singlyionized atomic species toward HD 43582. These components exhibit a combination of greatly enhanced thermal pressures and significantly reduced dust-grain depletions. We interpret this material as cooling gas in a recombination zone far downstream from shocks driven into neutral gas clumps. The pressures derived for a group of ionized gas components at high positive velocity toward HD 43582 are lower than those of the other shocked components, pointing to pressure inhomogeneities across the remnant. A strong very high velocity component near −620 km s −1 is seen in the absorption profiles of highly-ionized species toward HD 43582. The velocity of this material is consistent with the range of shock velocities implied by observations of soft thermal X-ray emission from IC 443. Moderately high-velocity gas toward HD 254755 may represent shocked material from a separate foreground supernova remnant.

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Section: Appendixmentioning

confidence: 99%

Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443

Ritchey,

Jenkins,

Federman

et al. 2020

Preprint

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“…are hence an important cooling process in the interstellar medium (Dalgarno & McCray 1972;Cowie & Songaila 1986, Pequignot 1990, Shaw et al 2006, Glover & Clark 2013 and may be a dominant mechanism at low temperatures (Dalgarno & McCray 1972).…”

Section: Introductionmentioning

confidence: 99%

Rate Constants for Fine-structure Excitations in O–H Collisions with Error Bars Obtained by Machine Learning

Vieira

Krems

2017

ApJ

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We present an approach using a combination of coupled channel scattering calculations with a machinelearning technique based on Gaussian Process regression to determine the sensitivity of the rate constants for non-adiabatic transitions in inelastic atomic collisions to variations of the underlying adiabatic interaction potentials. Using this approach, we improve the previous computations of the rate constants for the fine-structure transitions in collisions of O( 3 P j ) with atomic H. We compute the error bars of the rate constants corresponding to 20 % variations of the ab initio potentials and show that this method can be used to determine which of the individual adiabatic potentials are more or less important for the outcome of different fine-structure changing collisions.

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“…This paper is the defining documentation of Stout and should be cited if the database is used outside of Cloudy. Wang & McConkey (1992), Barklem (2007), Abrahamsson et al (2007), Krems et al (2006), Monteiro & Flower (1987), Jaquet et al (1992), Pequignot (1990…”

Section: Discussion and Summarymentioning

confidence: 99%

“…For an atomic hydrogen collider, very important in PDRs, we use data fromLaunay & Roueff (1977) for C I, fromAbrahamsson et al (2007);Krems et al (2006) for O I, fromHollenbach & McKee (1989) for Ne II, fromBarklem et al (2012) for Mg I, and fromBarinovs et al (2005) for Si II. For proton colliders, very important in collisions between levels with similar energies, we utilize data fromRoueff & Le Bourlot (1990) for C I and data fromPequignot (1990) for O I. For H 2 , data fromSchröder et al (1991) are employed for C I, data fromWiesenfeld & Goldsmith (2013) for the C II ion, and data fromJaquet et al (1992) for O I.…”

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confidence: 99%

Stout: Cloudy’s Atomic and Molecular Database

Lykins

Ferland

Kisielius

et al. 2015

ApJ

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We describe a new atomic and molecular database we developed for use in the spectral synthesis code Cloudy. The design of Stout is driven by the data needs of Cloudy, which simulates molecular, atomic, and ionized gas with kinetic temperatures 2.8 K < T < 10 10 K and densities spanning the low to high-density limits. The radiation field between photon energies 10 −8 Ry and 100 MeV is considered, along with all atoms and ions of the lightest 30 elements, and ∼ 10 2 molecules. For ease of maintenance, the data are stored in a format as close as possible to the original data sources. Few data sources include the full range of data we need. We describe how we fill in the gaps in the data or extrapolate rates beyond their tabulated range. We tabulate data sources both for the atomic spectroscopic parameters and for collision data for the next release of Cloudy. This is not intended as a review of the current status of atomic data, but rather a description of the features of the database which we will build upon.

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Conclusions

Cited by 7 publications

References 0 publications

Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443

Physical Conditions in Shocked Interstellar Gas Interacting with the Supernova Remnant IC 443

Rate Constants for Fine-structure Excitations in O–H Collisions with Error Bars Obtained by Machine Learning

Stout: Cloudy’s Atomic and Molecular Database

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