Nucleosynthesis in neutron-rich supernova ejecta

Hartmann, D.; Woosley, S. E.; Eid, M. F. El

doi:10.1086/163580

Cited by 184 publications

(108 citation statements)

References 0 publications

Supporting

Mentioning

101

Contrasting

Order By: Relevance

“…Using population synthesis, Yungelson & Livio (1998) . Similar constraints are also obtained from observed abundances of neutron-rich isotopes (Hartmann et al 1985;Fryer et al 1999). This would give a relative rate of …”

Section: Order-of-magnitude Estimatessupporting

confidence: 75%

Ultrahigh-Energy Cosmic Rays From the “En Caul” Birth of Magnetars*

Piro

Kollmeier

2016

ApJ

View full text Add to dashboard Cite

Rapidly spinning magnetars can potentially form through the accretion induced collapse of a white dwarf or by neutron star (NS) mergers if the equation of state of the nuclear density matter is such that two low-mass NSs can form a massive NS rather than a black hole. In either case, the newborn magnetar is an attractive site for the production of ultrahigh-energy cosmic rays (particles with individual energies exceeding 10 eV; 18 UHECRs). The short-period spin and strong magnetic field are able to accelerate particles up to appropriate energies, and the composition of material on and around the magnetar may naturally explain recent inferences of heavy elements in UHECRs. We explore whether the small amount of natal debris surrounding these magnetars allows UHECRs to escape easily. We also investigate the impact on the UHECRs of the unique environment around the magnetar, which consists of a bubble of relativistic particles and magnetic field within the debris. The rates and energetics of UHECRs are consistent with such an origin, even though the rates of events that produce rapidly spinning magnetars remain very uncertain. The low ejecta mass also helps the high-energy neutrino background associated with this scenario to be below current IceCube constraints over most of the magnetar parameter space. A unique prediction is that UHECRs may be generated in old stellar environments without strong star formation, in contrast to what would be expected for other UHECR scenarios, such as active galactic nuclei or long gamma-ray bursts.

show abstract

Section: Order-of-magnitude Estimatessupporting

confidence: 75%

Ultrahigh-Energy Cosmic Rays From the “En Caul” Birth of Magnetars*

Piro

Kollmeier

2016

ApJ

View full text Add to dashboard Cite

show abstract

“…For , the mass fraction landscape is composed of a sequence Y ! 0.5 e of overlapping abundance peaks (e.g., Clifford & Tayler 1965;Hartmann et al 1985;Nadyozhin & Yudin 2004). Fe-peak nuclei with a proton-to-nucleon ratio equal or close to the prescribed of the ensemble and a large binding energy per Y e nucleon, , are the most abundant nuclei.…”

Section: Resultsmentioning

confidence: 99%

Proton-rich Nuclear Statistical Equilibrium

Seitenzahl

Timmes

Marin-Lafleche

et al. 2008

ApJ

View full text Add to dashboard Cite

Proton-rich material in a state of nuclear statistical equilibrium (NSE) is one of the least studied regimes of nucleosynthesis. One reason for this is that after hydrogen burning, stellar evolution proceeds at conditions of an equal number of neutrons and protons or at a slight degree of neutron-richness. Proton-rich nucleosynthesis in stars tends to occur only when hydrogen-rich material that accretes onto a white dwarf or a neutron star explodes, or when neutrino interactions in the winds from a nascent proto-neutron star or collapsar disk drive the matter proton-rich prior to or during the nucleosynthesis. In this Letter we solve the NSE equations for a range of proton-rich thermodynamic conditions. We show that cold proton-rich NSE is qualitatively different from neutron-rich NSE. Instead of being dominated by the Fe-peak nuclei with the largest binding energy per nucleon that have a proton-to-nucleon ratio close to the prescribed electron fraction, NSE for proton-rich material near freezeout temperature is mainly composed of and free protons. Previous results of nuclear reaction 56 Ni network calculations rely on this nonintuitive high-proton abundance, which this Letter explains. We show how the differences and especially the large fraction of free protons arises from the minimization of the free energy as a result of a delicate competition between the entropy and nuclear binding energy.

show abstract

“…The production site of this isotope has been a long-standing question in the nucleosynthesis community (Meyer et al 1996). Previous scenarios to make 48 Ca include anomalous CCSN conditions in parts of the ejecta (Hartmann et al 1985), and the weak r-process (Wanajo et al 2013). It has been pointed out that H-ingestion events lead to Na production (Limongi & Chieffi 2012).…”

Section: Nucleosynthesis Calculationsmentioning

confidence: 99%

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Clarkson

Herwig

Pignatari

2017

Monthly Notices of the Royal Astronomical Society: Letters

View full text Add to dashboard Cite

We have investigated a highly energetic H-ingestion event during shell He burning leading to H-burning luminosities of log(L H /L ) ∼ 13 in a 45M Pop III massive stellar model. In order to track the nucleosynthesis which may occur in such an event, we run a series of single-zone nucleosynthesis models for typical conditions found in the stellar evolution model. Such nucleosynthesis conditions may lead to i-process neutron densities of up to ∼ 10 13 cm −3 . The resulting simulation abundance pattern, where Mg comes from He burning and Ca from the i process, agrees with the general observed pattern of the most iron-poor star currently known, SMSS J031300.36-670839.3. However, Na is also efficiently produced in these i process conditions, and the prediction exceeds observations by ∼ 2.5dex. While this probably rules out this model for SMSS J031300.36-670839.3, the typical i-process signature of combined He burning and i process of higher than solar [Na/Mg], [Mg/Al] and low [Ca/Mg] is reproducing abundance features of the two next most iron-poor stars HE 1017-5240 and HE 1327-2326 very well. The i process does not reach Fe which would have to come from a low level of additional enrichment. i process in hyper-metal poor or Pop III massive stars may be able to explain certain abundance patterns observed in some of the most-metal poor CEMP-no stars.

show abstract

Nucleosynthesis in neutron-rich supernova ejecta

Cited by 184 publications

References 0 publications

Ultrahigh-Energy Cosmic Rays From the “En Caul” Birth of Magnetars*

Ultrahigh-Energy Cosmic Rays From the “En Caul” Birth of Magnetars*

Proton-rich Nuclear Statistical Equilibrium

Pop III i-process nucleosynthesis and the elemental abundances of SMSS J0313−6708 and the most iron-poor stars

Contact Info

Product

Resources

About