Modeling the remnants of core-collapse supernovae from luminous blue variable stars

Context. Luminous blue variable stars (LBVs) are massive evolved stars that suffer sporadic and violent mass-loss events. They have been proposed as the progenitors of some core-collapse supernovae (SNe), but this idea is still debated because of a lack of strong evidence. As supernova remnants (SNRs) can carry in their morphology the fingerprints of the progenitor stars as well as of the inhomogeneous circumstellar medium (CSM) sculpted by the progenitors, the study of SNRs from LBVs could help to place core-collapse SNe in context with the evolution of massive stars. Aims. We investigate the physical, chemical, and morphological properties of the remnants of SNe originating from LBVs in order to search for signatures in the ejecta distribution and morphology of the remnants that could reveal the nature of the progenitors. Methods. As a template of LBVs, we considered the LBV candidate Gal 026.47+0.02. We selected a grid of models that describe the evolution of a massive star with properties consistent with those of Gal 026.47+0.02 and its final fate as a core-collapse SN. We developed a three-dimensional hydrodynamic model that follows the post-explosion evolution of the ejecta from the breakout of the shock wave at the stellar surface to the interaction of the SNR with a CSM characterized by two dense nested toroidal shells, parametrized in agreement with multi-wavelength observations of Gal 026.47+0.02. Results. Our models show a strong interaction of the blast wave with the CSM which determines an important slowdown of the expansion of the ejecta in the equatorial plane where the two shells lay, determining a high degree of asymmetry in the remnant. After ≈10 000 yr of evolution, the ejecta show an elongated shape forming a broad jet-like structure caused by the interaction with the shells and oriented along the axis of the toroidal shells. Models with high explosion energy show Fe-rich internal ejecta distributions surrounded by an elongated Si-rich structure with a more diffuse O-rich ejecta all around. Models with low explosion energy instead show a more homogeneous distribution of chemical elements with a very low presence of Fe-group elements. Conclusions. The geometry and density distribution of the CSM where a LBV star goes SN are fundamental in determining the properties of the resulting SNR. For all the LBV-like progenitors explored here, we found that the remnants show a common morphology, namely elongated ejecta with an internal jet-like structure, which reflects the inhomogeneous and dense pre-SN CSM surrounding the star.

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The impact of fallback on the compact remnants and chemical yields of core-collapse supernovae

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1431 ◽

2020 ◽

Vol 495 (4) ◽

pp. 3751-3762 ◽

Cited By ~ 10

Author(s):

Conrad Chan ◽

Bernhard Müller ◽

Alexander Heger

Keyword(s):

Binding Energy ◽

Gamma Ray ◽

Three Dimensional ◽

Explosion Energy ◽

Core Collapse ◽

Abundance Patterns ◽

Small Set ◽

The Impact ◽

Disc Formation ◽

Three Dimensional Simulations

ABSTRACT Fallback in core-collapse supernovae plays a crucial role in determining the properties of the compact remnants and of the ejecta composition. We perform three-dimensional simulations of mixing and fallback for selected non-rotating supernova models to study how explosion energy and asymmetries correlate with the remnant mass, remnant kick, and remnant spin. We find that the strongest kick and spin are imparted by partial fallback in an asymmetric explosion. Black hole (BH) kicks of several hundred $\mathrm{km}\, \mathrm{s}^{-1}$ and spin parameters of $\mathord {\sim }0.25$ can be obtained in this scenario. If the initial explosion energy barely exceeds the envelope binding energy, stronger fallback results, and the remnant kick and spin remain small. If the explosion energy is high with respect to the envelope binding energy, there is little fallback with a small effect on the remnant kick, but the spin-up by fallback can be substantial. For a non-rotating $12\, \mathrm{M}_\odot$ progenitor, we find that the neutron star is spun up to millisecond periods. The high specific angular momentum of the fallback material can also lead to disc formation around BHs. Fallback may thus be a pathway towards millisecond-magnetar or collapsar-type engines for hypernovae and gamma-ray bursts that does not require rapid progenitor rotation. Within our small set of simulations, none reproduced the peculiar layered fallback necessary to explain the metal-rich iron-poor composition of many carbon-enhanced metal-poor (CEMP) stars. Models with different explosion energy and different realizations of asymmetries may, however, be compatible with CEMP abundance patterns.

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Extrusion Based 3D Printing of Sustainable Biocomposites from Biocarbon and Poly(trimethylene terephthalate)

Molecules ◽

10.3390/molecules26144164 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4164

Author(s):

Elizabeth Diederichs ◽

Maisyn Picard ◽

Boon Peng Chang ◽

Manjusri Misra ◽

Amar Mohanty

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Surface Finish ◽

Three Dimensional ◽

Morphological Properties ◽

Great Promise ◽

Structural Components ◽

Computer Aided ◽

Trimethylene Terephthalate ◽

Optimal Quantity

Three-dimensional (3D) printing manufactures intricate computer aided designs without time and resource spent for mold creation. The rapid growth of this industry has led to its extensive use in the automotive, biomedical, and electrical industries. In this work, biobased poly(trimethylene terephthalate) (PTT) blends were combined with pyrolyzed biomass to create sustainable and novel printing materials. The Miscanthus biocarbon (BC), generated from pyrolysis at 650 °C, was combined with an optimized PTT blend at 5 and 10 wt % to generate filaments for extrusion 3D printing. Samples were printed and analyzed according to their thermal, mechanical, and morphological properties. Although there were no significant differences seen in the mechanical properties between the two BC composites, the optimal quantity of BC was 5 wt % based upon dimensional stability, ease of printing, and surface finish. These printable materials show great promise for implementation into customizable, non-structural components in the electrical and automotive industries.

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Radiation-Driven Stellar Eruptions

Galaxies ◽

10.3390/galaxies8010010 ◽

2020 ◽

Vol 8 (1) ◽

pp. 10 ◽

Cited By ~ 2

Author(s):

Kris Davidson

Keyword(s):

Mass Loss ◽

Radiation Pressure ◽

Central Region ◽

Massive Stars ◽

Variable Stars ◽

Blast Waves ◽

Subsequent Evolution ◽

Fundamental Causes ◽

Radiative Output ◽

Luminous Blue Variable

Very massive stars occasionally expel material in colossal eruptions, driven by continuum radiation pressure rather than blast waves. Some of them rival supernovae in total radiative output, and the mass loss is crucial for subsequent evolution. Some are supernova impostors, including SN precursor outbursts, while others are true SN events shrouded by material that was ejected earlier. Luminous Blue Variable stars (LBV’s) are traditionally cited in relation with giant eruptions, though this connection is not well established. After four decades of research, the fundamental causes of giant eruptions and LBV events remain elusive. This review outlines the basic relevant physics, with a brief summary of essential observational facts. Reasons are described for the spectrum and emergent radiation temperature of an opaque outflow. Proposed mechanisms are noted for instabilities in the star’s photosphere, in its iron opacity peak zones, and in its central region. Various remarks and conjectures are mentioned, some of them relatively unfamiliar in the published literature.

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Morphological and Physiological Characterization of Layer VI Corticofugal Neurons of Mouse Primary Visual Cortex

Journal of Neurophysiology ◽

10.1152/jn.01051.2002 ◽

2003 ◽

Vol 89 (5) ◽

pp. 2854-2867 ◽

Cited By ~ 37

Author(s):

Joshua C. Brumberg ◽

Farid Hamzei-Sichani ◽

Rafael Yuste

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Action Potentials ◽

Three Dimensional ◽

Cell Types ◽

Dorsal Lateral Geniculate Nucleus ◽

Morphological Properties ◽

Feedback Connection ◽

Physiological Characterization ◽

Layer Vi

Layer VI is the origin of the massive feedback connection from the cortex to the thalamus, yet its complement of cell types and their connections is poorly understood. The physiological and morphological properties of corticofugal neurons of layer VI of mouse primary visual cortex were investigated in slices loaded with the Ca2+indicator fura-2AM. To identify corticofugal neurons, electrical stimulation of the white matter (WM) was done in conjunction with calcium imaging to detect neurons that responded with changes in intracellular Ca2+ concentrations in response to the stimulation. Subsequent whole cell recordings confirmed that they discharged antidromic action potentials after WM stimulation. Antidromically activated neurons were more excitable and had different spiking properties than neighboring nonantidromic neurons, although both groups had similar input resistances. Furthermore, antidromic neurons possessed narrower action potentials and smaller afterhyperpolarizations. Additionally, three-dimensional reconstructions indicated that antidromically activated neurons had a distinct morphology with longer apical dendrites and fewer nonprimary dendrites than nonantidromic cells. To identify the antidromic neurons, rhodamine microspheres were injected into the dorsal lateral geniculate nucleus of the thalamus and allowed to retrogradely transport back to the somata of the layer VI cortico-geniculate neurons. Physiological and anatomical analysis indicated that most antidromic neurons were likely to be cortico-geniculate neurons. Our results show that cortico-thalamic neurons represent a specific functional and morphological class of layer VI neurons.

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The distribution of myosin II in Dictyostelium discoideum slug cells.

The Journal of Cell Biology ◽

10.1083/jcb.115.5.1267 ◽

1991 ◽

Vol 115 (5) ◽

pp. 1267-1274 ◽

Cited By ~ 12

Author(s):

S Eliott ◽

P H Vardy ◽

K L Williams

Keyword(s):

Cell Motility ◽

Dictyostelium Discoideum ◽

Immunofluorescence Microscopy ◽

Molecular Genetic ◽

Myosin Ii ◽

Three Dimensional ◽

Homogeneous Distribution ◽

Multicellular Development ◽

Insight Into

While the role of myosin II in muscle contraction has been well characterized, less is known about the role of myosin II in non-muscle cells. Recent molecular genetic experiments on Dictyostelium discoideum show that myosin II is necessary for cytokinesis and multicellular development. Here we use immunofluorescence microscopy with monoclonal and polyclonal antimyosin antibodies to visualize myosin II in cells of the multicellular D. discoideum slug. A subpopulation of peripheral and anterior cells label brightly with antimyosin II antibodies, and many of these cells display a polarized intracellular distribution of myosin II. Other cells in the slug label less brightly and their cytoplasm displays a more homogeneous distribution of myosin II. These results provide insight into cell motility within a three-dimensional tissue and they are discussed in relation to the possible roles of myosin II in multicellular development.

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Radio detection of nebulae around four luminous blue variable stars in the Large Magellanic Cloud

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2012.21791.x ◽

2012 ◽

Vol 426 (1) ◽

pp. 181-186 ◽

Cited By ~ 6

Author(s):

C. Agliozzo ◽

G. Umana ◽

C. Trigilio ◽

C. Buemi ◽

P. Leto ◽

...

Keyword(s):

Large Magellanic Cloud ◽

Variable Stars ◽

Magellanic Cloud ◽

Radio Detection ◽

Luminous Blue Variable

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New method of holographic three-dimensional tracking of living cells exploiting their morphological properties

Digital Holography and Three-Dimensional Imaging ◽

10.1364/dh.2013.dtu2a.5 ◽

2013 ◽

Author(s):

Pasquale Memmolo ◽

Maria Iannone ◽

Maurizio Ventre ◽

Paolo Antonio Netti ◽

Andrea Finizio ◽

...

Keyword(s):

Three Dimensional ◽

Living Cells ◽

New Method ◽

Morphological Properties

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Effect of 3D printer enabled surface morphology and composition on coral growth in artificial reefs

Rapid Prototyping Journal ◽

10.1108/rpj-07-2020-0165 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Ilse Valenzuela Matus ◽

Jorge Lino Alves ◽

Joaquim Góis ◽

Augusto Barata da Rocha ◽

Rui Neto ◽

...

Keyword(s):

Additive Manufacturing ◽

Chemical Composition ◽

Chemical Elements ◽

Three Dimensional ◽

Coral Growth ◽

Coralline Algae ◽

Textured Surface ◽

Crustose Coralline Algae ◽

Statistical Parameters ◽

Content Type

Purpose The purpose of this paper is to prove and qualify the influence of textured surface substrates morphology and chemical composition on the growth and propagation of transplanted corals. Use additive manufacturing and silicone moulds for converting three-dimensional samples into limestone mortar with white Portland cement substrates for coral growth. Design/methodology/approach Tiles samples were designed and printed with different geometries and textures inspired by nature marine environment. Commercial coral frag tiles were analysed through scanning electron microscopy (SEM) to identify the main chemical elements. Raw materials and coral species were selected. New base substrates were manufactured and deployed into a closed-circuit aquarium to monitor the coral weekly evolution process and analyse the results obtained. Findings Experimental results provided positive statistical parameters for future implementation tests, concluding that the intensity of textured surface, interfered favourably in the coralline algae biofilm growth. The chemical composition and design of the substrates were determinant factors for successful coral propagation. Recesses and cavities mimic the natural rocks aspect and promoted the presence and interaction of other species that favour the richness of the ecosystem. Originality/value Additive manufacturing provided an innovative method of production for ecology restoration areas, allowing rapid prototyping of substrates with high complexity morphologies, a critical and fundamental attribute to guarantee coral growth and Crustose Coralline Algae. The result of this study showed the feasibility of this approach using three-dimensional printing technologies.

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Diversity and distribution patterns of the Oligocene and Miocene decapod crustaceans (Crustacea: Malacostraca) of the Western and Central Paratethys

Geologica Carpathica ◽

10.1515/geoca-2016-0030 ◽

2016 ◽

Vol 67 (5) ◽

pp. 471-494 ◽

Cited By ~ 5

Author(s):

Matúš Hyžný

Keyword(s):

Spatial Scales ◽

Three Dimensional ◽

Decapod Crustacean ◽

Distribution Patterns ◽

Mediterranean Area ◽

Homogeneous Distribution ◽

Decapod Crustaceans ◽

Central Paratethys ◽

The North ◽

Marine Habitats

AbstractDecapod associations have been significant components of marine habitats throughout the Cenozoic when the major diversification of the group occurred. In this respect, the circum-Mediterranean area is of particular interest due to its complex palaeogeographic history. During the Oligo-Miocene, it was divided in two major areas, Mediterranean and Paratethys. Decapod crustaceans from the Paratethys Sea have been reported in the literature since the 19thcentury, but only recent research advances allow evaluation of the diversity and distribution patterns of the group. Altogether 176 species-level taxa have been identified from the Oligocene and Miocene of the Western and Central Paratethys. Using the three-dimensional NMDS analysis, the composition of decapod crustacean faunas of the Paratethys shows significant differences through time. The Ottnangian and Karpatian decapod associations were similar to each other both taxonomically and in the mode of preservation, and they differed taxonomically from the Badenian ones. The Early Badenian assemblages also differed taxonomically from the Late Badenian ones. The time factor, including speciation, immigration from other provinces and/or (local or global) extinction, can explain temporal differences among assemblages within the same environment. High decapod diversity during the Badenian was correlated with the presence of reefal settings. The Badenian was the time with the highest decapod diversity, which can, however, be a consequence of undersampling of other time slices. Whereas the Ottnangian and Karpatian decapod assemblages are preserved virtually exclusively in the siliciclastic “Schlier”-type facies that originated in non-reefal offshore environments, carbonate sedimentation and the presence of reefal environments during the Badenian in the Central Paratethys promoted thriving of more diverse reef-associated assemblages. In general, Paratethyan decapods exhibited homogeneous distribution during the Oligo-Miocene among the basins in the Paratethys. Based on the co-occurrence of certain decapod species, migration between the Paratethys and the North Sea during the Early Miocene probably occurred via the Rhine Graben. At larger spatial scales, our results suggest that the circum-Mediterranean marine decapod taxa migrated in an easterly direction during the Oligocene and/or Miocene, establishing present-day decapod communities in the Indo-West Pacific.

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