CHEMISTRY OF A PROTOPLANETARY DISK WITH GRAIN SETTLING AND Lyα RADIATION

Fogel, Jeffrey K. J.; Bethell, Thomas J.; Bergin, Edwin A.; Calvet, Nuria; Semenov, D.

doi:10.1088/0004-637x/726/1/29

Cited by 136 publications

(223 citation statements)

References 73 publications

(106 reference statements)

Supporting

Mentioning

212

Contrasting

Order By: Relevance

“…To explore this theory and its dependencies more directly we have used the chemical models of Fogel et al 43 and Cleeves et al 44 . Briefly these models adopt realistic disk physical structures (gas density and temperature, dust temperature, dust properties) motivated by resolved disk observations and the overall spectral energy distribution 16 .…”

Section: Chemical Modelmentioning

confidence: 99%

Exploring the origins of carbon in terrestrial worlds^†

et al. 2014

View full text Add to dashboard Cite

Given the central role of carbon in the chemistry of life, it is a fundamental question as to how carbon is supplied to the Earth, in what form and when. We provide an accounting of carbon found in solar system bodies, in particular a comparison between the organic content of meteorites and that in identified organics in the dense interstellar medium (ISM). Based on this accounting identified organics created by the chemistry of star formation could contain at most ∼15% of the organic carbon content in primitive meteorites and significantly less for cometary organics, which represent the putative contributors to starting materials for the Earth. In the ISM ∼ 30% of the elemental carbon is found in CO, either in the gas or ices, with a typical abundance of ∼ 10 −4 (relative to H 2 ). Recent observations of the TW Hya disk find that the gas phase abundance of CO is reduced by an order of magnitude compared to this value. We explore a solution where the volatile CO is destroyed via a gas phase processes, providing an additional source of carbon for organic material to be incorporated into planetesimals and cometesimals. This chemical processing mechanism requires warm grains (> 20 K), partially ionized gas, and sufficiently small (a grain < 10 µm) grains, i.e. a larger total grain surface area, such that freeze-out is efficient. Under these conditions static (non-turbulent) chemical models predict that a large fraction of the carbon nominally sequestered in CO can be the source of carbon for a wide variety of organics that are present as ice coatings on the surfaces of warm pre-planetesimal dust grains.

show abstract

Section: Chemical Modelmentioning

confidence: 99%

Exploring the origins of carbon in terrestrial worlds^†

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The A24, page 4 of 20 presence of Ly α photons deep inside a non-settled disk model of TW Hya does change the abundance pattern of HCN, but has very little impact on e.g. CO (Fogel et al 2011); for some species such as water and OH, Ly α dissociation is roughly compensated by increased Ly α photodesorption. Hogerheijde et al (2011) used the same underlying 2D density structure and grain size distribution as Thi et al (2010a) and hence as our "standard model".…”

Section: Comparison With Other Disk Modelsmentioning

confidence: 99%

Uncertainties in water chemistry in disks: An application to TW Hydrae

Kamp¹,

Thi

Meeus

et al. 2013

A&A

View full text Add to dashboard Cite

Context. This paper discusses the sensitivity of water lines to chemical processes and radiative transfer for the protoplanetary disk around TW Hya. The study focuses on the Herschel spectral range in the context of new line detections with the PACS instrument from the Gas in Protoplanetary Systems project (GASPS). Aims. The paper presents an overview of the chemistry in the main water reservoirs in the disk around TW Hya. It discusses the limitations in the interpretation of observed water line fluxes. Methods. We use a previously published thermo-chemical Protoplanetary Disk Model (ProDiMo) of the disk around TW Hya and study a range of chemical modeling uncertainties: metallicity, C/O ratio, and reaction pathways and rates leading to the formation of water. We provide results for the simplified assumption of T gas = T dust to quantify uncertainties arising for the complex heating/cooling processes of the gas and elaborate on limitations due to water line radiative transfer. Conclusions. Due to their sensitivity on chemical input data and radiative transfer, water lines have to be used cautiously for understanding details of the disk structure. Water lines covering a wide range of excitation energies provide access to the various gas phase water reservoirs (inside and outside the snow line) in protoplanetary disks and thus provide important information on where gas-phase water is potentially located. Experimental and/or theoretical collision rates for H 2 O with atomic hydrogen are needed to diminish uncertainties from water line radiative transfer.

show abstract

“…The line in both plots refers to the τ = 1 surface for stellar radiation and = 1 refers to the fact that these models were run with a standard dust to gas ratio. All model results taken from Fogel et al (2010). water lines. We use the collision rates of water with p-H 2 from Faure et al (2007) as provided by the LAMDA database (Schöier et al 2005) 3 and convolved the results with the appropriate Herschel beams.…”

Section: Comparison To Observationsmentioning

confidence: 99%

Sensitive limits on the abundance of cold water vapor in the DM Tauri protoplanetary disk

Bergin¹,

Hogerheijde

Brinch

et al. 2010

A&A

View full text Add to dashboard Cite

We performed a sensitive search for the ground-state emission lines of ortho-and para-water vapor in the DM Tau protoplanetary disk using the Herschel/HIFI instrument. No strong lines are detected down to 3σ levels in 0.5 km s −1 channels of 4.2 mK for the 1 10 -1 01 line and 12.6 mK for the 1 11 −0 00 line. We report a very tentative detection, however, of the 1 10 -1 01 line in the wide band spectrometer, with a strength of T mb = 2.7 mK, a width of 5.6 km s −1 and an integrated intensity of 16.0 mK km s −1 . The latter constitutes a 6σ detection. Regardless of the reality of this tentative detection, model calculations indicate that our sensitive limits on the line strengths preclude efficient desorption of water in the UV illuminated regions of the disk. We hypothesize that more than 95−99% of the water ice is locked up in coagulated grains that have settled to the midplane.

show abstract

CHEMISTRY OF A PROTOPLANETARY DISK WITH GRAIN SETTLING AND Lyα RADIATION

Cited by 136 publications

References 73 publications

Exploring the origins of carbon in terrestrial worlds^†

Exploring the origins of carbon in terrestrial worlds^†

Uncertainties in water chemistry in disks: An application to TW Hydrae

Sensitive limits on the abundance of cold water vapor in the DM Tauri protoplanetary disk

Contact Info

Product

Resources

About

CHEMISTRY OF A PROTOPLANETARY DISK WITH GRAIN SETTLING AND Lyα RADIATION

Cited by 136 publications

References 73 publications

Exploring the origins of carbon in terrestrial worlds†

Exploring the origins of carbon in terrestrial worlds†

Uncertainties in water chemistry in disks: An application to TW Hydrae

Sensitive limits on the abundance of cold water vapor in the DM Tauri protoplanetary disk

Contact Info

Product

Resources

About

Exploring the origins of carbon in terrestrial worlds^†

Exploring the origins of carbon in terrestrial worlds^†