arXiv subjects

Nico Koning

Publications and source records attributed to Nico Koning.

At least 19 recordsLinked to original sources

arXiv2024

The Quark-Nova model for FRBs: model comparison with observational data

We utilize the Quark-Novae (QN) model for Fast Radio Bursts (FRBs; Ouyed et al. 2021; arXiv:2005.09793) to evaluate its performance in reproducing the distribution and statistical properties of key observations. These include frequency, duration, fluence, dispersion measure (DM), and other relevant features such as repetition, periodic activity window, and the sad trombone effect. In our model, FRBs are attributed to coherent synchrotron emission (CSE) originating from collisionless QN chunks that traverse ionized media both within and outside their host galaxies. By considering burst repetition from a single chunk and accounting for the intrinsic DM of the chunks, we find agreement between our model and the observed properties of FRBs. This agreement enhances our confidence in the model's effectiveness for interpreting FRB observations. Our model generates testable predictions, allowing for future experiments and observations to validate and further refine our understanding of FRBs.

astro-ph.HE↗

arXiv2023

Quark clusters, QCD vacuum and the cosmological 7Li, Dark Matter and Dark Energy problems

We propose a non-exotic electromagnetic solution (within the standard model of particle physics) to the cosmological 7Li problem based upon a narrow 2 MeV photo-emission line from the decay of light Glueballs (LGBs). These LGBs form within color superconducting, tens of Fermi in size, quark clusters (SQCs) in the radiation-dominated post-BBN epoch. The mono-chromatic line from the LGB -> gamma+gamma decay reduces Big-Bang nucleosynthesis (BBN) 7Be by 2/3 without affecting other abundances or CMB physics, provided the combined mass of the SQCs is greater than the total baryonic mass in the Universe. Following the LGB emission, the in-SQC Quantum-ChromoDynamics (QCD) vacuum becomes unstable and "leaks" (via quantum tunnelling) into the external space-time (trivial) vacuum inducing a decoupling of SQCs from hadrons. In seeking a solution to the 7Li problem, we uncovered a solution which also addresses the dark energy (DE) and dark matter (DM) problem making these critical problems intertwined in our model. Being colorless, charge neutral, optically thin and transparent to hadrons, SQCs interact only gravitationally making them a viable CDM candidate. The quantum tunnelling of the in-SQC QCD vacuum to the trivial vacuum offers an explanation of DE in our model and allows for a cosmology which evolves into a LambdaCDM universe at low redshift with a possible resolution of the Hubble tension. Our model distinguishes itself by proposing that the QCD vacuum within SQCs possesses the ability to tunnel into the exterior trivial vacuum, resulting in the generation of DE. This implies the possibility that DM and hadrons might represent distinct phases of quark matter within QCD, characterized by different vacuum properties. We discuss SQC formation in heavy-ion collision experiments at moderate temperatures and the possibility of detection of MeV photons from LGB -> gamma+gamma.

astro-ph.CO↗

arXiv2022

Molecules in the peculiar age-defying source IRAS 19312+1950

Context. IRAS 19312+1950 is an isolated infrared source that exhibits a characteristic quasi-point-symmetric morphology in the near- and mid-infrared images and is also very bright in molecular radio lines. Because of its unique observational characteristics, various observational studies have been conducted and several hypotheses have been proposed regarding its origin, which is still unclear. So far, it has been suggested that it could be a peculiar evolved star, a young stellar object, or even a red nova remnant. Regardless of which type of object it is ultimately classified as, IRAS 19312+1950 is exceptionally bright in the infrared and molecular radio lines and therefore will undoubtedly be crucial as a prototype of this kind of object having a peculiar nature or unusual evolutionary phase. Aims. This study aims to reveal the molecular composition of the central part of IRAS 19312+1950 by performing an unbiased molecular radio line survey and discussing the origin of the object from a molecular chemical point of view. Methods. We carried out a spectral line survey with the IRAM 30 m telescope towards the center of IRAS 19312+1950 in the 3 and 1.3 mm windows. Results. In total, 28 transition lines of 22 molecular species and those isotopologues are detected towards IRAS 19312+1950, some of which exhibit a broad and a narrow components. Seventeen thermal lines and 1 maser line are newly detected. The molecular species of C$^{17}$O, $^{30}$SiO, HN$^{13}$C, HC$^{18}$O$^{+}$, H$_{2}$CO, and $c$-C$_{3}$H$_{2}$ are detected for the first time in this object. Conclusions. Our results, in combination with previous studies, favor the hypothesis that IRAS 19312+1950 might be a red nova remnant, in which the progenitors that merged to become a red nova may have contained at least two evolved stars with oxygen-rich and carbon-rich chemistry, respectively.

astro-ph.GA↗

arXiv2022

Morphokinematic modelling of the point-symmetric Cat's Eye, NGC 6543: Ring-like remnants of a precessing jet

The planetary nebula known as the Cat's Eye Nebula (NGC 6543) has a complex, point-symmetric morphology that cannot be fully explained by the current theory of planetary nebula formation, the Interacting Stellar Winds Model. In order to reveal the three dimensional (3D) structure of the Cat's Eye Nebula, we created a detailed 3D morpho-kinematic model of this nebula using a [NII] image from the Hubble Space Telescope and five different position-velocity diagrams using the SHAPE code. This modeling approach has revealed point-symmetric partial rings, which were likely formed by a precessing jet.

astro-ph.SR↗

arXiv2021

Quark-Novae in the outskirts of galaxies: An explanation of the Fast Radio Burst phenomenon

We show that old isolated neutron stars in groups and clusters of galaxies experiencing a Quark-Nova phase (QN: an explosive transition to a quark star) may be the source of FRBs. Each of the millions of fragments of the ultra-relativistic QN ejecta provides a collisionless plasma for which the ambient medium (galactic/halo, the intra-group/intra-cluster medium) acts as a relativistic plasma beam. The Buneman and the Weibel instabilities, successively induced by the beam in the fragment, generate particle bunching and observed coherent emission at GHz frequency with a corresponding fluence in the Jy ms range. The duration, frequency drift and the rate are in agreement with observed properties of FRBs. Repeats (on timescales of minutes to months) are due to seeing multiple fragments each beaming at a different direction and coming in at different times. Single (non-repeating) FRBs, occur when only emission from the primary fragment is within the detector's sensitivity. Key properties of FRB 121102 (its years of activity) and of FRB 180916.J0158+65 (its 16 day period) are recovered. The spatial and temporal coincidence between SGR 1935+2154 and FRB 200428 finds an explanation in our model. We give testable predictions.

astro-ph.HE↗

arXiv2019

A Quark-Nova in the wake of a core-collapse Supernova: a unifying model for long duration Gamma-Ray Bursts and Fast Radio Bursts

[Abridged] By appealing to a Quark-Nova (QN; the explosive transition of a neutron star to a quark star) in the wake of a core-collapse Supernova explosion of a massive star, we develop a unified model for long duration Gamma-ray Bursts (LGRBs) and Fast Radio Bursts (FRBs). The time delay (years to decades) between the SN and the QN and, the fragmented nature (i.e. millions of chunks) of the relativistic QN ejecta are key to yielding a robust LGRB engine. In our model, a LGRB light-curve exhibits the interaction of the fragmented QN ejecta with a turbulent (i.e. filamentary and magnetically saturated) SN ejecta which is shaped by its interaction with an underlying pulsar wind nebula (PWN). The afterglow is due to the interaction of the QN chunks, exiting the SN ejecta, with the surrounding medium. Our model can fit BAT/XRT prompt and afterglow light-curves, simultaneously with their spectra, thus yielding the observed properties of LGRBs (e.g. the Band function and the X-ray flares). We find that the Yonetoku law and the Amati law are not fundamental but phenomenological. FRBs result from coherent synchrotron emission when the QN chunks interact with non-turbulent weakly magnetized PWN-SN ejecta, where conditions are prone to the Weibel instability. Magnetic field amplification induced by the Weibel instability sets the bunching length for electrons and pairs to radiate coherently. The resulting emission frequency, luminosity, duration and dispersion measure in our model are consistent with FRB data. We find a natural unification of high-energy burst phenomena from FRBs to LGRBs including X-ray Flashes and X-ray rich GRBs as well as Super-Luminous SNe. We find a possible connection between Ultra-High Energy Cosmic Rays and FRBs and propose that a QN following a binary neutron star merger can yield a short GRB (SGRB) with fits to BAT/XRT light-curves.

astro-ph.HE↗

arXiv2017

Hybrid polygon and hydrodynamic nebula modeling with multi-waveband radiation transfer in astrophysics

We demonstrate the potential for research and outreach of mixed polygon and hydrodynamic modeling and multi-waveband rendering in the interactive 3-D astrophysical virtual laboratory Shape. In 3-D special effects and animation software for the mass media, computer graphics techniques that mix polygon and numerical hydrodynamics have become common place. In astrophysics, however, interactive modeling with polygon structures has only become available with the software Shape. Numerical hydrodynamic simulations and their visualization are usually separate, while in Shape it is integrated with the polygon modeling approach that requires no programming by the user. With two generic examples, we demonstrate that research and outreach modeling can be achieved with techniques similar to those used in the media industry with the added capability for physical rendering at any wavelength band, yielding more realistic radiation modeling. Furthermore, we show how the hydrodynamics and the polygon mesh modeling can be mixed to achieve results that are superior to those obtained using either one of these modeling techniques alone.

astro-ph.IM↗

arXiv2017

Critical assessment of nuclear sensitivity metrics for the r-process

Any simulation of the r-process is affected by uncertainties in our present knowledge of nuclear physics quantities and astrophysical conditions. It is common to quantify the impact of these uncertainties through a global sensitivity metric, which is then used to identify specific nuclides that would be most worthwhile to measure experimentally. Using descriptive statistics, we assess a set of metrics used in previous sensitivity studies, as well as a new logarithmic measure. For certain neutron-rich nuclides lying near the r-process path for the typical hot-wind scenario, we find opposing conclusions on their relative sensitivity implied by different metrics, although they all generally agree which ones are the most sensitive nuclei. The underlying reason is that sensitivity metrics which simply sum over variations in the r-process distribution depend on the scaling used in the baseline, which often varies between simulations. We show that normalization of the abundances causes changes in the reported sensitivity factors and recommend reporting a minimized F statistic in addition to a scale estimation for rough calibration to be used when comparing tables of sensitivity factors from different studies.

astro-ph.HE↗

arXiv2016

The Superluminous (Type I) Supernova ASASSN-15lh : A case for a Quark-Nova inside an Oxygen-type Wolf-Rayet supernova remnant

We show that a Quark-Nova (QN; the explosive transition of a neutron star to a quark star) occurring a few days following the supernova explosion of an Oxygen-type Wolf-Rayet (WO) star can account for the intriguing features of ASASSN-15lh, including its extreme energetics, its double-peaked light-curve and the evolution of its photospheric radius and temperature. A two-component configuration of the homologously expanding WO remnant (an extended envelope and a compact core) is used to harness the kinetic energy (>10^52 ergs) of the QN ejecta. The delay between the WO SN and the QN yields a large (~ 10^4 Rsun) envelope which when energized by the QN ejecta/shock gives the first peak in our model. As the envelope's photosphere recedes into the slowly expanding, hot and insulated, denser core (initially heated by the QN shock) a second hump emerges. The spectrum in our model should reflect the composition of an WO SN remnant re-heated by a QN going off in its wake.

astro-ph.HE↗

arXiv2016

Quark-Noave in binaries: Observational signatures and implications to astrophysics

The explosive transition of a massive neutron star to a quark star (the Quark-Nova, QN) releases in excess of ~ 10^52 erg in kinetic energy which can drastically impact the surrounding environment of the QN. A QN is triggered when a neutron star gains enough mass to reach the critical value for quark deconfinement to happen in the core. In binaries, a neutron star has access to mass reservoirs (e.g. accretion from a companion or from a Common Envelope, CE). We explain observed light-curves of hydrogen-poor superluminous Supernovae (SLSNe Ia) in the context of a QN occurring in the second CE phase of a massive binary. In particular this model gives good fits to light-curves of SLSNe with double-humped light-curves. Our model suggests the QN as a mechanism for CE ejection and that they be taken into account during binary evolution. In a short period binary with a white dwarf companion, the neutron star can quickly grow in mass and experience a QN event. Part of the QN ejecta collides with the white dwarf, shocking, compressing, and heating it to driving a thermonuclear runaway producing a SN Ia impostor (a QN-Ia). Unlike "normal" Type Ia supernovae where no compact remnant is formed, a QN-Ia produces a quark star undergoing rapid spin-down providing additional power along with the 56Ni decay energy. Type Ia SNe are used as standard candles and contamination of this data by QNe-Ia can infer an incorrect cosmology.

astro-ph.HE↗

arXiv2016

Quark-nova compact remnants: Observational signatures in astronomical data and implications to compact stars

Quark-novae leave behind quark stars with a surrounding metal-rich fall-back (ring-like) material. These compact remnants have high magnetic fields and are misconstrued as magnetars; however, several observational features allow us to distinguish a quark star (left behind by a quark-nova) from a neutron star with high magnetic field. In our model, bursting activity is expected from intermittent accretion events from the surrounding fall-back debris leading to X-ray bursts (in the case of a Keplerian ring) or gamma ray bursts (in the case of a co-rotating shell). The details of the spectra are described by a constant background X-ray luminosity from the expulsion of magnetic flux tubes which will be temporarily buried by bursting events caused by accretion of material onto the quark star surface. These accretion events emit high energy photons and heat up the quark star and surrounding debris leading to hot spots which may be observable as distinct blackbodies. Additionally, we explain observed spectral line features as atomic lines from r-process material and explain an observed anti-glitch in an AXP as the transfer of angular momentum from a surrounding Keplerian disk to the quark star.

astro-ph.HE↗

arXiv2016

Quark-Novae occurring in massive binaries : A universal energy source in superluminous Supernovae with double-peaked light curves

A Quark-Nova (QN, the sudden transition from a neutron star into a quark star) which occurs in the second common envelope (CE) phase of a massive binary (Ouyed et al., 2015a&b), gives excellent fits to super-luminous, hydrogen-poor, Supernovae (SLSNe) with double-peaked light curves including DES13S2cmm, SN 2006oz and LSQ14bdq (http://www.quarknova.ca/LCGallery.html). In our model, the H envelope of the less massive companion is ejected during the first CE phase while the QN occurs deep inside the second, He-rich, CE phase after the CE has expanded in size to a radius of a few tens to a few thousands solar radii, this yields the first peak in our model. The ensuing merging of the quark star with the CO core leads to black hole formation and accretion explaining the second long-lasting peak. We study a sample of 8 SLSNe Ic with double-humped light-curves. Our model provides good fits to all of these with a universal explosive energy of 2x10^52 erg (which is the kinetic energy of the QN ejecta) for the first hump. The late-time emissions seen in iPTF13ehe and LSQ14bdq are fit with a shock interaction between the outgoing He-rich (i.e second) CE and the previously ejected H-rich (i.e first) CE.

astro-ph.HE↗

arXiv2016

Quark Nova Model for Fast Radio Bursts

FRBs are puzzling, millisecond, energetic radio transients with no discernible source; observations show no counterparts in other frequency bands. The birth of a quark star from a parent neutron star experiencing a quark nova - previously thought undetectable when born in isolation - provides a natural explanation for the emission characteristics of FRBs. The generation of unstable r-process elements in the quark nova ejecta provides millisecond exponential injection of electrons into the surrounding strong magnetic field at the parent neutron star's light cylinder via $β$-decay. This radio synchrotron emission has a total duration of hundreds of milliseconds and matches the observed spectrum while reducing the inferred dispersion measure by approximately 200 cm$^{-3}$ pc. The model allows indirect measurement of neutron star magnetic fields and periods in addition to providing astronomical measurements of $β$-decay chains of unstable neutron rich nuclei. Using this model, we can calculate expected FRB average energies ($\sim$ 10$^{41}$ ergs), spectra shapes and provide a theoretical framework for determining distances.

astro-ph.HE↗

arXiv2015

The superluminous SN DES13S2cmm as a signature of a Quark-Nova in a He-HMXB system

We show that by appealing to a Quark-Nova (the explosive transition of a neutron star to a quark star) occurring in an He-HMXB system we can account for the lightcurve of the first superluminous SN, DES13S2cmm, discovered by the Dark-Energy Survey. The neutron star's explosive conversion is triggered as a result of accretion during the He-HMXB second Common Envelope phase. The dense, relativistic, Quark-Nova ejecta in turn energizes the extended He-rich Common Envelope in an inside-out shock heating process. We find an excellent fit (reduced chi^2 of 1.09) to the bolometric light-curve of SN DES13S2cmm including the late time emission, which we attribute to Black Hole accretion following the conversion of the Quark Star to a Black hole.

astro-ph.HE↗

arXiv2015

Quark-Novae in massive binaries : a model for double-humped, hydrogen-poor, superluminous Supernovae

LSQ14bdq and SN 2006oz are super-luminous, hydrogen-poor, SNe with double-humped light curves. We show that a Quark-Nova (QN; explosive transition of the neutron star to a quark star) occurring in a massive binary, experiencing two Common Envelope (CE) phases, can quantitatively explain the light curves of LSQ14bdq and SN 2006oz. The more massive component (A) explodes first as a normal SN, yielding a Neutron Star which ejects the hydrogen envelope of the companion when the system enters its first CE phase. During the second CE phase, the NS spirals into and inflates the second He-rich CE. In the process it gains mass and triggers a Quark-Nova, outside of the CO core, leaving behind a Quark Star. The first hump in our model is the QN shock re-energizing the expanded He-rich CE. The QN occurs when the He-rich envelope is near maximum size (~ 1000R_sun) and imparts enough energy to unbind and eject the envelope. Subsequent merging of the Quark Star with the CO core of component B, driven by gravitational radiation, turns the Quark star to a Black Hole. The ensuing Black Hole accretion provides sufficient power for the second brighter and long lasting hump. Our model suggests a possible connection between SLSNe-I and type Ic-BL SNe which occur when the Quark Nova is triggered inside the CO core. We estimate the rate of QNe in massive binaries during the second CE phase to be ~ 5x10^(-5) of that of core-collapse SNe.

astro-ph.HE↗

arXiv2015

The Burn-UD code for the numerical simulations of the Hadronic-to-Quark-Matter phase transition

Burn-UD is a hydrodynamic combustion code used to model the phase transition of hadronic to quark matter with particular application to the interior of neutron stars. Burn-UD models the flame micro-physics for different equations of state (EoS) on both sides of the interface, i.e. for both the ash (up-down-strange quark phase) and the fuel (up-down quark phase). It also allows the user to explore strange quark seeding produced by different processes including DM annihilation inside neutron stars. The simulations provide a physical window to diagnose whether the combustion process will simmer quietly and slowly, lead to a transition from deflagration to detonation or a (quark) core-collapse explosion. Such an energetic phase transition (a Quark-Nova) would have consequences in high-energy astrophysics and could aid in our understanding of many still enigmatic astrophysical transients. Furthermore, having a precise understanding of the phase transition dynamics for different EoSs could aid further in constraining the nature of the non-perturbative regimes of QCD in general. We hope that Burn-UD will evolve into a platform/software to be used and shared by the QCD community exploring the phases of Quark Matter and astrophysicists working on Compact Stars.

astro-ph.HE↗

arXiv2015

The puzzling early detection of low velocity 56Ni decay lines in SN 2014J: Hints of a compact remnant

We show that the low-velocity 56Ni decay lines detected earlier than expected in the type Ia SN 2014J find an explanation in the Quark-Nova Ia model which involves the thermonuclear explosion of a tidally disrupted sub-Chandrasekhar White Dwarf in a tight Neutron-Star-White-Dwarf binary system. The explosion is triggered by impact from the Quark-Nova ejecta on the WD material; the Quark-Nova is the explosive transition of the Neutron star to a Quark star triggered by accretion from a CO torus (the circularized WD material). The presence of a compact remnant (the Quark Star) provides: (i) an additional energy source (spin-down power) which allows us to fit the observed light-curve including the steep early rise; (ii) a central gravitational potential which slows down some of the 56Ni produced to velocities of a few 1000 km/s. In our model, the 56Ni decay lines become optically visible at ~20 days from explosion time in agreement with observations. We list predictions that can provide important tests for our model.

astro-ph.HE↗

arXiv2014

HST-Scale 3D simulations of MHD disc winds : A rotating two-component jet structure

We present the results of large scale, three-dimensional magneto-hydrodynamics simulations of disc-winds for different initial magnetic field configurations. The jets are followed from the source to 90 AU scale, which covers several pixels of HST images of nearby protostellar jets. Our simulations show that jets are heated along their length by many shocks. We compute the emission lines that are produced, and find excellent agreement with observations. The jet width is found to be between 20 and 30 AU while the maximum velocities perpendicular to the jet is found to be up to above 100 km/s. The initially less open magnetic field configuration simulations results in a wider, two-component jet; a cylindrically shaped outer jet surrounding a narrow and much faster, inner jet. These simulations preserve the underlying Keplerian rotation profile of the inner jet to large distances from the source. However, for the initially most open magnetic field configuration the kink mode creates a narrow corkscrew-like jet without a clear Keplerian rotation profile and even regions where we observe rotation opposite to the disc (counter-rotating). The RW Aur jet is narrow, indicating that the disc field in that case is very open meaning the jet can contain a counter-rotating component that we suggests explains why observations of rotation in this jet has given confusing results. Thus magnetized disc winds from underlying Keplerian discs can develop rotation profiles far down the jet that are not Keplerian.

astro-ph.SR↗