Abstract Core-collapse supernova (CCSN) explosions powered by rotation and magnetic fields present an interesting astrophysical site for nucleosynthesis that potentially contributes to the production ...of r -process elements. Here we present yields of the innermost ejecta in 3D magnetorotational CCSN models simulated using the CoCoNuT-FMT code. Strong magnetic fields tap the rotational energy of the proto−neutron star and lead to earlier and more energetic (∼3 × 10 51 erg) explosions than typical neutrino-driven CCSNe. Compared to a reference nonmagnetic model, the ejecta in the magnetorotational models have much more neutron-rich components with Y e down to ∼0.25. Our post-processing calculations with the reaction network SkyNet show significant production of weak r -process elements up to mass number ∼130. We find negligible differences in the synthesis of heavy elements between two magnetorotational models with different initial field strengths of 10 10 and 10 12 G, in accord with their similar explosion dynamics. The magnetorotational models produce about ∼0.19 and 0.14 M ☉ of radioactive 56 Ni, on the low end of inferred hypernova nickel masses. The yields are publicly available at Zenodo (doi: 10.5281/zenodo.10578981) for comparison with stellar abundance patterns, inclusion in modeling galactic chemical evolution, and comparison with other yield calculations. Our results add to the yet-restricted corpus of nucleosynthesis yields from 3D magnetorotational supernova simulations and will help quantify yield uncertainties.
Stars with ∼8-10 M evolve to form a strongly degenerate ONeMg core. When the core mass becomes close to the Chandrasekhar mass, the core undergoes electron captures on 24Mg and 20Ne that induce an ...electron-capture supernova (ECSN). In order to clarify whether the ECSN leads to a collapse or thermonuclear explosion, we calculate the evolution of an 8.4 M star from the main sequence until the oxygen ignition in the ONeMg core. We apply the latest electron-capture rate on 20Ne, including the second forbidden transition, and investigate how the location of the oxygen ignition (center or off-center) and the Ye distribution depend on the input physics and the treatment of the semiconvection and convection. The central density when the oxygen deflagration is initiated, c,def, can be significantly higher than that of the oxygen ignition thanks to the convection, and we estimate . We perform two-dimensional simulations of the flame propagation to examine how the final fate of the ONeMg core depends on the Ye distribution and c,def. We find that the deflagration starting from leads to a collapse (thermonuclear explosion). Since our estimate of c,def exceeds this critical value, the ONeMg core is likely to collapse, although further studies of the convection and semiconvection before the deflagration are important.
Abstract
Type IIP supernovae (SNe IIP) mark the explosive death of red supergiants (RSGs), evolved massive stars with an extended hydrogen envelope. They are the most common supernova type and allow ...for the benchmarking of supernova explosion models by statistical comparison to observed population properties rather than by comparing individual models and events. We construct a large synthetic set of SNe IIP light curves (LCs) using the radiation hydrodynamics code
SNEC
and explosion energies and nickel masses obtained from an efficient semianalytic model for two different sets of stellar progenitor models. By direct comparison, we demonstrate that the semianalytic model yields very similar predictions as alternative phenomenological explosion models based on 1D simulations. We find systematic differences of a factor of ∼2 in plateau luminosities between the two progenitor sets due to different stellar radii, which highlights the importance of the RSG envelope structure as a major uncertainty in interpreting the LCs of SNe IIP. A comparison to a volume-limited sample of observed SNe IIP shows decent agreement in plateau luminosity, plateau duration, and nickel mass for at least one of the synthetic LC sets. The models, however, do not produce sufficient events with very small nickel mass
M
Ni
< 0.01
M
⊙
and predict an anticorrelation between plateau luminosity and plateau duration that is not present in the observed sample, a result that warrants further study. Our results suggest that a better understanding of RSG stellar structure is no less important for reliably explaining the LCs of SNe IIP than the explosion physics.
Hydrogen sulfide (H2S), a third gas signaling molecule, is considered to play a vital role in the development and treatment of diseases. To elucidate the intricate role of H2S in the organism and its ...participation in disease processes, there is an urgent need to visualize the dynamics of H2S. However, most currently available molecular probes have limitations in terms of sensitivity, specificity, and precision. In this study, the safe and biocompatible upconversion nanosensor NaYF4:Yb3+, Tm3+@NaYF4 anchored with Ag2O was successfully fabricated for H2S detection with an ultralow detection limit at 0.93 ng/mL. NaYF4:Yb3+, Tm3+@NaYF4@Ag2S is formed through in situ sulfuration reaction, and second near-infrared (NIR-II) fluorescence can be recorded upon the presence of H2S under 808 nm excitation. The results demonstrate the exceptional detection linearity and high specificity for H2S quantification. Additionally, NaYF4:Yb3+, Tm3+@NaYF4@Ag2O possesses a safe nature in normal and cancer cells. This nanosensor presents a NIR fluorescence imaging strategy for highly sensitive and specific detection of H2S, which has promises to be a practical tool for biomedical applications.
Abstract
We study the consequences of a hadron-quark phase transition (PT) in failing core-collapse supernovae (CCSNe) that give birth to stellar-mass black holes (BH). We perform a suite of ...neutrino-transport general-relativistic hydrodynamic simulations in spherical symmetry with 21 progenitor models and a hybrid equation of state (EoS) including hadrons and quarks. We find that the effect of the PT on the CCSN postbounce dynamics is a function of the bounce compactness parameter
. For
, the PT leads to a second dynamical collapse of the protocompact star (PCS). While BH formation starts immediately after this second collapse for models with
, the PCS experiences a second bounce and oscillations for models with
. These models emit potent oscillatory neutrino signals with a period of ∼1 ms for tens of milliseconds after the second bounce, which can be a strong indicator of the PT in failing CCSNe if detected in the future. However, no shock revival occurs and BH formation inevitably takes place in our spherically symmetric simulations. Furthermore, via a diagram of mass-specific entropy evolution of the PCS, the progenitor dependence can be understood through the appearance of a third family of compact stars emerging at large entropy induced by the PT.
A first-order quantum chromodynamics (QCD) phase transition (PT) may take place in the protocompact star (PCS) produced by a core-collapse supernova (CCSN). In this work, we study the consequences of ...such a PT in a nonrotating CCSN with axisymmetric hydrodynamic simulations. We find that the PT leads to the collapse of the PCS and results in a loud burst of gravitational waves (GWs). The amplitude of this GW burst is ∼ 30 times larger than the postbounce GW signal normally found for nonrotating CCSN. It shows a broad peak at high frequencies ( ∼ 2500 – 4000 Hz ) in the spectrum, has a duration of ≲ 5 ms , and carries ∼ 3 orders of magnitude more energy than the other episodes. Also, the peak frequency of the PCS oscillation increases dramatically after the PT-induced collapse. In addition to a second neutrino burst, the GW signal, if detected by the ground-based GW detectors, is decisive evidence of the first-order QCD PT inside CCSNe and provides key information about the structure and dynamics of the PCS.
ABSTRACT
We present neutrino-transport hydrodynamic simulations of electron-capture supernovae (ECSNe) in flash with new two-dimensional (2D) collapsing progenitor models. These progenitor models ...feature the 2D modelling of oxygen-flame propagation until the onset of core collapse. We perform axisymmetric simulations with six progenitor models that, at the time of collapse, span a range of propagating flame front radii. For comparison, we also perform a simulation with the same set-up using the canonical, spherically symmetrical progenitor model n8.8. We found that the variations in the progenitor models inherited from simulations of stellar evolution and flame propagation do not significantly alter the global properties of the neutrino-driven ECSN explosion, such as the explosion energy (∼1.36–1.48 × 1050 erg) and the mass (∼0.017–0.018 M⊙) and composition of the ejecta. Due to aspherical perturbations induced by the 2D flame, the ejecta contains a small amount (≲1.8 × 10−3 M⊙) of low-Ye (0.35 < Ye < 0.4) component. The baryonic mass of the protoneutron star is ∼1.34 M⊙ (∼1.357 M⊙) with the new (n8.8) progenitor models when simulations end at ∼400 ms and the discrepancy is due to updated weak-interaction rates in the progenitor evolutionary simulations. Our results reflect the nature of ECSN progenitors containing a strongly degenerate oxygen–neon–magnesium (ONeMg) core and suggest a standardized ECSN explosion initialized by ONeMg core collapse. Moreover, we carry out a rudimentary three-dimensional simulation and find that the explosion properties are fairly compatible with the 2D counterpart. Our paper facilitates a more thorough understanding of ECSN explosions following the ONeMg core collapse, though more three-dimensional simulations are still needed.
Abstract
Gravitational waves (GWs) provide unobscured insight into the birthplace of neutron stars and black holes in core-collapse supernovae (CCSNe). The nuclear equation of state (EOS) describing ...these dense environments is yet uncertain, and variations in its prescription affect the proto−neutron star (PNS) and the post-bounce dynamics in CCSN simulations, subsequently impacting the GW emission. We perform axisymmetric simulations of CCSNe with Skyrme-type EOSs to study how the GW signal and PNS convection zone are impacted by two experimentally accessible EOS parameters, (1) the effective mass of nucleons,
m
⋆
, which is crucial in setting the thermal dependence of the EOS, and (2) the isoscalar incompressibility modulus,
K
sat
. While
K
sat
shows little impact, the peak frequency of the GWs has a strong effective mass dependence due to faster contraction of the PNS for higher values of
m
⋆
owing to a decreased thermal pressure. These more compact PNSs also exhibit more neutrino heating, which drives earlier explosions and correlates with the GW amplitude via accretion plumes striking the PNS, exciting the oscillations. We investigate the spatial origin of the GWs and show the agreement between a frequency-radial distribution of the GW emission and a perturbation analysis. We do not rule out overshoot from below via PNS convection as another moderately strong excitation mechanism in our simulations. We also study the combined effect of effective mass and rotation. In all our simulations we find evidence for a power gap near ∼1250 Hz; we investigate its origin and report its EOS dependence.
We developed a novel nanocomposite consisted of UCNP, tetraphenyl porphyrin and GOx for detecting glucose based on upconversion luminescence quenching recovery, and it can achieve glucose detection ...and carcinoma cells inhibition in vitro simultaneously.
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•Highly sensitive and rapid detection of glucose was established based on upconversion luminescence quenching recovery.•The functionalized nanoprobe with tetraphenyl porphyrin was facilely developed and it possessed dual excitation wavelength.•The designed nanocomposite could achieve glucose detection and carcinoma cells inhibition in vitro simultaneously.
In this work, we introduce the upconverting detection nanoprobes UCNP-TPP-GOx based on the upconversion quenching effect recovery for the ultrasensitive, expeditious, quantitative, and in vitro cellular detection of glucose. This nanoplatform consists of upconversion nanoparticles (UCNP), tetraphenyl porphyrin (TPP) and glucose oxidase (GOx). In a nutshell, UCNPs core are linked with cancer-killing TPP via condensation reaction to form UCNP-TPP, subsequently, UCNP-TPP-GOx is fabricated through glucose oxidase (GOx) decoration on the surface of the UCNP-TPP. Additionally, UCNP-TPP-GOx possesses characteristic photophysical property and it is highly suitable for optical detection. Furthermore, UCNP-TPP-GOx shows excellent selectivity toward glucose after only 3-min coincubation and the limit of detection (LOD) for the glucose is calculated as low as 0.86 μg mL−1. Moreover, the differentiation between cancer and normal cells through in vitro confocal imaging is achieved due to the large differences of glucose level in them. More importantly, the significant inhibition on carcinoma cell growth is realized by simply switching to the specific excitation wavelength, followed by the generation of toxic singlet oxygen from TPP moiety. Hence, the developed nanoprobes presenting new possibilities for on-site rapid glucose detection and concurrent theranostics in vitro in a “one stone two birds” strategy.
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