Effects of Preionization in Radiative Shocks. I. Self-consistent Models

Sutherland, Ralph S.; Dopita, Michael A.

doi:10.3847/1538-4365/aa6541

Cited by 115 publications

(76 citation statements)

References 29 publications

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“…At the distance of HuBi 1 and adopting a volume filling factor of 0.3 [25], this density implies an ionized mass of 0.08 M ⊙ , which is reasonable value for a PN. The code MAPPINGS V 5.1.13 [27] was used to explore the evolution of the intensity of various emission lines in a freely cooling gas. The Supplementary Figure 4 shows the time-evolution of the electronic temperature, ionization fraction of hydrogen, and emissivity of several emission lines for a spherical photo-ionized cloud of gas once the ionizing source is switched off and the gas is allowed to cool freely.…”

Section: Methodsmentioning

confidence: 99%

The inside-out planetary nebula around a born-again star

et al. 2018

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Planetary nebulae are ionized clouds of gas formed by the hydrogen-rich envelopes of low-and intermediate-mass stars ejected at late evolutionary stages. The strong UV flux from their central stars causes a highly stratified ionization structure, with species of higher ionization potential closer to the star. Here we report on the exceptional case of HuBi 1, a double-shell planetary nebula whose inner shell presents emission from low-ionization species close to the star and emission from high-ionization species farther away. Spectral analysis demonstrates that the inner shell of HuBi 1 is excited by shocks, whereas its outer shell is recombining. The anomalous excitation of these shells can be traced to its low-temperature [WC10] central star whose optical brightness has declined continuously by 10 magnitudes in a period of 46 years. Evolutionary models reveal that this star is the descendent of a low-mass star (≃ 1.1 M ⊙ ) that has experienced a born-again event[1] whose ejecta shock-excite the inner shell. HuBi 1 represents the missing link in the formation of metal-rich central stars of planetary nebulae from low-mass progenitors, offering unique insight regarding the future evolution of the born-again Sakurai's object [2]. Coming from a solar-mass progenitor, HuBi 1 represents a potential end-state for our Sun.Planetary nebulae (PNe) are a short-lived ≈20,000 yr period in the transition of lowand intermediate-mass stars (M initial = 0.8 − 8.0M ⊙ ) from the Asymptotic Giant Branch (AGB) phase towards the white-dwarf (WD) phase. The ionization structure of PNe, 1

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Section: Methodsmentioning

confidence: 99%

The inside-out planetary nebula around a born-again star

et al. 2018

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“…shocks -which might affect ion abundances and emission line intensities (cfr. Sutherland & Dopita 2017;Sutherland et al 2018). However, the typical PDR code (Röllig et al 2007) includes -and models more accurately -a larger number of physical processes with respect to the ones typically considered in hydrodynamical simulations with radiative transfer.…”

Section: Consistency Of the Post-processingmentioning

confidence: 99%

Deep into the structure of the first galaxies: SERRA views

Pallottini

Ferrara

Decataldo

et al. 2019

Monthly Notices of the Royal Astronomical Society

139

193

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We study the formation and evolution of a sample of Lyman Break Galaxies in the Epoch of Reionisation by using high-resolution (∼ 10 pc), cosmological zoom-in simulations part of the serra suite. In serra, we follow the interstellar medium (ISM) thermo-chemical non-equilibrium evolution, and perform on-the-fly radiative transfer of the interstellar radiation field (ISRF). The simulation outputs are post-processed to compute the emission of far infrared lines ([C II], [N II], and [O III]). At z = 8, the most massive galaxy, "Freesia", has an age t 409 Myr, stellar mass M 4.2 × 10 9 M , and a star formation rate SFR 11.5 M yr −1 , due to a recent burst. Freesia has two stellar components (A and B) separated by 2.5 kpc; other 11 galaxies are found within 56.9 ± 21.6 kpc. The mean ISRF in the Habing band is G = 7.9 G 0 and is spatially uniform; in contrast, the ionisation parameter is U = 2 +20 −2 × 10 −3 , and has a patchy distribution peaked at the location of star-forming sites. The resulting ionising escape fraction from Freesia is f esc 2%. While [C II] emission is extended (radius 1.54 kpc), [O III] is concentrated in Freesia-A (0.85 kpc), where the ratio Σ [OIII] /Σ [CII] 10. As many high-z galaxies, Freesia lies below the local [C II]-SFR relation. We show that this is the general consequence of a starburst phase (pushing the galaxy above the Kennicutt-Schmidt relation) which disrupts/photodissociates the emitting molecular clouds around star-forming sites. Metallicity has a sub-dominant impact on the amplitude of [C II]-SFR deviations.

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“…We will explore this possibility in forthcoming studies. As a first approach, models with shock (like MAPPINGS models, Sutherland & Dopita 2017) could be used to study the contribution of shocks, using, for example, the grid recently published by Alarie & Morisset (2019).…”

Section: Hii Regions Along Galactocentric Distancesmentioning

confidence: 99%

H ii regions in the CALIFA survey: I. catalogue presentation

Espinosa-Ponce

Sánchez

Morisset

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We present a new catalog of H ii regions based on the integral field spectroscopy (IFS) data of the extended CALIFA and PISCO samples. The selection of H ii regions was based on two assumptions: a clumpy structure with high contrast of Hα emission and an underlying stellar population comprising young stars. The catalog provides the spectroscopic information of 26,408 individual regions corresponding to 924 galaxies, including the flux intensities and equivalent widths of 51 emission lines covering the wavelength range between 3745-7200Å. To our knowledge, this is the largest catalog of spectroscopic properties of H ii regions. We explore a new approach to decontaminate the emission lines from diffuse ionized gas contribution. This diffuse gas correction was estimated to correct every emission line within the considered spectral range. With the catalog of H ii regions corrected, new demarcation lines are proposed for the classical diagnostic diagrams. Finally, we study the properties of the underlying stellar populations of the H ii regions. It was found that there is a direct relationship between the ionization conditions on the nebulae and the properties of stellar populations besides the physicals condition on the ionized regions.

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Effects of Preionization in Radiative Shocks. I. Self-consistent Models

Cited by 115 publications

References 29 publications

The inside-out planetary nebula around a born-again star

The inside-out planetary nebula around a born-again star

Deep into the structure of the first galaxies: SERRA views

H ii regions in the CALIFA survey: I. catalogue presentation

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