The Irradiation Origin of Beryllium Radioisotopes and Other Short‐lived Radionuclides

Gounelle, M.; Shu, Frank H.; Shang, Hsien; Glassgold, A. E.; Rehm, K.E.; Lee, Typhoon

doi:10.1086/500309

Cited by 122 publications

(161 citation statements)

References 51 publications

Supporting

Mentioning

151

Contrasting

Unclassified

Order By: Relevance

“…This implies that the duration of irradiation of individual solid targets or the duration of SLR condensation from an irradiated gas, , is much shorter than the SLR halfind T irr lives. The x-wind model is in agreement with this assumption for most SLRs since solids are constantly transported close to the star, irradiated over a short timescale, yr ind T p 1-100 irr depending on their size (Gounelle et al 2001), before being ejected at large distances on the accretion disk. However, as noted by Leya et al (2003) and Gounelle et al (2006) final production).…”

Section: Maximum Production Yieldssupporting

confidence: 62%

“…Different scenarios have been proposed to explain the abundance of the SLRs in the ESS but a global astrophysical interpretation accounting for all of them is still lacking (see Wasserburg et al 2006 for a recent review). The possibility of producing SLRs by in situ irradiation has been extensively discussed and challenged in the last decade (Lee et al 1998;Gounelle et al 2001Gounelle et al , 2006Goswami et al 2001;Leya et al 2003), but all these studies addressed, above all, the issue of producing the canonical abundance ratios locally within a given target. Yet, a crucial issue is the total amount of nuclei that can be synthesized within such a process.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Energetic Constraints on In Situ Production of Short-Lived Radionuclei in the Early Solar System

Duprat

Tatischeff

2007

ApJ

View full text Add to dashboard Cite

We calculate upper limits on the amount of short-lived radionuclei that can be produced by nonthermal nucleosynthesis in the early solar system. Using energetic constraints obtained from X-ray observations of young stellar objects, we show that irradiation of bare solids can produce 10 Be and 41 Ca at levels compatible with a homogeneous distribution over the entire protoplanetary disk up to the comet-forming region. 53 Mn and 36 Cl cannot be produced at canonical levels together with 10 Be and 41 Ca, unless we posit a heterogeneous spatial distribution. The high level of 7 Be suggested recently is barely compatible with a coproduction of 10 Be up to the cometary reservoir and may indicate the irradiation of a gas phase. Finally, we show that the maximum amount of irradiation-induced 26 Al can only account for a homogeneous distribution of this radionuclide over a rocky reservoir of 2-3 M and that the well-defined canonical 26 Al/ 27 Al ratio observed in Ca-Al-rich inclusions is probably not compatible with an in situ production in the embedded phase of the Sun. If extinct 26 Al is detected in the cometary material from the Stardust mission, the nucleosynthetic process that produced this preeminent high-resolution chronometer should be searched for in stellar events contemporary with the birth of the Sun.

show abstract

Section: Maximum Production Yieldssupporting

confidence: 62%

mentioning

confidence: 99%

Energetic Constraints on In Situ Production of Short-Lived Radionuclei in the Early Solar System

Duprat

Tatischeff

2007

ApJ

View full text Add to dashboard Cite

show abstract

“…One likely explanation for these abundance anomalies are spallation reactions of SPs with the dust in the protosolar nebula (e.g. Lee et al 1998b;McKeegan et al 2000;Gounelle et al 2001Gounelle et al , 2006. However, this would require a strongly enhanced SP flux of the young Sun by a factor 3 × 10 5 compared to the contemporary Sun (McKeegan et al 2000), consistent with the estimated SP flux of T Tauri stars derived by Feigelson et al (2002).…”

Section: Introductionsupporting

confidence: 65%

Stellar energetic particle ionization in protoplanetary disks around T Tauri stars

Rab

Güdel

Padovani

et al. 2017

A&A

102

View full text Add to dashboard Cite

Context. Anomalies in the abundance measurements of short lived radionuclides in meteorites indicate that the protosolar nebulae was irradiated by a high amount of energetic particles (E 10 MeV). The particle flux of the contemporary Sun cannot explain these anomalies. However, similar to T Tauri stars the young Sun was more active and probably produced enough high energy particles to explain those anomalies. Aims. We want to study the interaction of stellar energetic particles with the gas component of the disk (i.e. ionization of molecular hydrogen) and identify possible observational tracers of this interaction. Methods. We use a 2D radiation thermo-chemical protoplanetary disk code to model a disk representative for T Tauri stars. We use a particle energy distribution derived from solar flare observations and an enhanced stellar particle flux proposed for T Tauri stars. For this particle spectrum we calculate the stellar particle ionization rate throughout the disk with an accurate particle transport model. We study the impact of stellar particles for models with varying X-ray and cosmic-ray ionization rates. Results. We find that stellar particle ionization has a significant impact on the abundances of the common disk ionization tracers HCO + and N 2 H + , especially in models with low cosmic-ray ionization rates (e.g. 10 −19 s −1 for molecular hydrogen). In contrast to cosmic rays and X-rays, stellar particles cannot reach the midplane of the disk. Therefore molecular ions residing in the disk surface layers are more affected by stellar particle ionization than molecular ions tracing the cold layers/midplane of the disk. Conclusions. Spatially resolved observations of molecular ions tracing different vertical layers of the disk allow to disentangle the contribution of stellar particle ionization from other competing ionization sources. Modeling such observations with a model like the one presented here allows to constrain the stellar particle flux in disks around T Tauri stars.

show abstract

“…41 Ca, with a half life of only 0.1 Myr, or 10 Be, with a half life of 1.5 Myr), which therefore cannot be originating in SN nucleosynthesis but must instead be originating in situ (as discussed in detail by e.g. Gounelle et al 2006). While the observed isotopic anomalies likely require proton (rather than electron) bombardment, our observations provide evidence of in situ acceleration mechanisms closely associated with neutral material from the star's circumstellar disk, that is, an environment where accelerated nonthermal particles interact with the protoplanetary material from which the meteorites will later grow.…”

Section: Discussionmentioning

confidence: 99%

Results from Droxo

Giardino¹,

Favata

Pillitteri

et al. 2007

A&A

View full text Add to dashboard Cite

Aims. We study the variability of the Fe 6.4 keV emission line from the Class I young stellar object Elias 29 in the ρ Oph cloud. Methods. We analysed the data from Elias 29 collected by XMM-Newton during a nine-day, nearly continuous observation of the ρ Oph star-forming region (the Deep Rho-Oph X-ray Observation, named droxo). The data were subdivided into six homogeneous time intervals, and the six resulting spectra were individually analysed. Results. We detect significant variability in the equivalent width of the Fe 6.4 keV emission line from Elias 29. The 6.4 keV line is absent during the first time interval of observation and appears at its maximum strength during the second time interval (90 ks after Elias 29 undergoes a strong flare). The X-ray thermal emission is unchanged between the two observation segments, while line variability is present at a 99.9% confidence level. Given the significant line variability in the absence of variations in the X-ray ionising continuum and the weakness of the photoionising continuum from the star's thermal X-ray emission, we suggest that the fluorescence may be induced by collisional ionisation from an (unseen) population of non-thermal electrons. We speculate on the possibility that the electrons are accelerated in a reconnection event of a magnetically confined accretion loop, connecting the young star to its circumstellar disk.

show abstract

The Irradiation Origin of Beryllium Radioisotopes and Other Short‐lived Radionuclides

Cited by 122 publications

References 51 publications

Energetic Constraints on In Situ Production of Short-Lived Radionuclei in the Early Solar System

Energetic Constraints on In Situ Production of Short-Lived Radionuclei in the Early Solar System

Stellar energetic particle ionization in protoplanetary disks around T Tauri stars

Results from Droxo

Contact Info

Product

Resources

About