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we present independent determinations of cosmological parameters using the distance estimator based on the established correlation between the balmer line luminosity, l(h β), and the velocity dispersion (σ) for h ii galaxies (hiig). these results are based on new vlt-kmos high spectral resolution observations of 41 hig... | independent cosmological constraints from high-z h ii galaxies: new results from vlt-kmos data |
white-dwarf stars are the end product of stellar evolution for most stars in the universe. their interiors bear the imprint of fundamental mechanisms that occur during stellar evolution. moreover, they are important chronometers for dating galactic stellar populations, and their mergers with other white dwarfs now appe... | a large oxygen-dominated core from the seismic cartography of a pulsating white dwarf |
recent theory predicts that first stars are born with a massive initial mass of ≳100 m ⊙. pair-instability supernova (pisn) is a common fate for such massive stars. our final goal is to prove the existence of pisne and thus the high-mass nature of the initial mass function in the early universe by conducting abundance ... | stellar yields of rotating first stars. ii. pair-instability supernovae and comparison with observations |
context. massive binaries play a crucial role in the universe. knowing the distributions of their orbital parameters is important for a wide range of topics from stellar feedback to binary evolution channels and from the distribution of supernova types to gravitational wave progenitors, yet no direct measurements exist... | the tarantula massive binary monitoring. i. observational campaign and ob-type spectroscopic binaries |
the galactic center is dominated by the gravity of a super-massive black hole (smbh), sagittarius a*, and is suspected to contain a sizable population of binary stars. such binaries form hierarchical triples with the smbh, undergoing eccentric kozai-lidov (ekl) evolution, which can lead to high-eccentricity excitations... | the fate of binaries in the galactic center: the mundane and the exotic |
we implement a detailed dust model into the l-galaxies semi-analytical model which includes: injection of dust by type ii and type ia supernovae (sne) and agb stars; grain growth in molecular clouds; and destruction due to supernova-induced shocks, star formation, and reheating. our grain growth model follows the dust ... | detailed dust modelling in the l-galaxies semi-analytic model of galaxy formation |
we study the connection of star formation to atomic (h i) and molecular hydrogen (h2) in isolated, low-metallicity dwarf galaxies with high-resolution (mgas = 4 m⊙, nngb = 100) smoothed particle hydrodynamics simulations. the model includes self-gravity, non-equilibrium cooling, shielding from a uniform and constant in... | star formation and molecular hydrogen in dwarf galaxies: a non-equilibrium view |
invisible neutrino decay modes are difficult to target at laboratory experiments, and current bounds on such decays from solar neutrino and neutrino oscillation experiments are somewhat weak. it has been known for some time that cosmology can serve as a powerful probe of invisible neutrino decays. in this work, we show... | cosmological constraints on invisible neutrino decays revisited |
we consider the possible observation of fast radio bursts (frbs) with planned future radio telescopes, and investigate how well the dispersions and redshifts of these signals might constrain cosmological parameters. we construct mock catalogs of frb dispersion measure (dm) data and employ markov chain monte carlo analy... | future cosmological constraints from fast radio bursts |
the quaternary compound copper manganese tin sulfide cu2mnsns4 is a potential absorber semiconductor material for fabricating thin film solar cells (tfsc) thanks to their promising optoelectronic parameters. this article numerically investigated the performance of cu2mnsns4 (cmts)-based tfsc without and with tin sulphi... | high efficiency cu2mnsns4 thin film solar cells with sns bsf and cds etl layers: a numerical simulation |
we perform smoothed particle hydrodynamics (sph) simulations of an isolated galaxy with a new treatment for dust formation and destruction. to this aim, we treat dust and metal production self-consistently with star formation and supernova (sn) feedback. for dust, we consider a simplified model of grain size distributi... | galaxy simulation with dust formation and destruction |
using the largest spectroscopic data set of stripped-envelope core-collapse supernovae (stripped sne), we present a systematic investigation of spectral properties of type iib sne (sne iib), type ib sne (sne ib), and type ic sne (sne ic). prior studies have been based on individual objects or small samples. here, we an... | analyzing the largest spectroscopic data set of stripped supernovae to improve their identifications and constrain their progenitors |
we present the observations made by several china-based amateur astronomers that cover the onset of sn 2023ixf. a serendipitous time-lapse observation of m 101 captured the onset of the supernova explosion and constrained the onset time at around 2023 may 18 19:30 to 20:30 ut. | onset of sn 2023ixf observed over east asian longitudes |
we present mid-infrared (mid-ir) imaging of the type iil supernova (sn) 1980k with the james webb space telescope (jwst) more than 40 yr post-explosion. sn 1980k, located in the nearby ($d\approx7$ mpc) "sn factory" galaxy ngc 6946, was serendipitously captured in jwst/miri images taken of the field of sn 2004et in the... | serendipitous detection of the dusty type iil sn 1980k with jwst/miri |
superradiant clouds may develop around a rotating black hole, if there is a bosonic field with compton wavelength comparable to the size of the black hole. in this paper, we investigate the effects of the cloud on the orbits of nearby compact objects. in particular, we consider the dynamical friction and the backreacti... | dynamic signatures of black hole binaries with superradiant clouds |
we present griz light curves of 251 sne ia from the first 3 years of the dark energy survey supernova program’s (des-sn) spectroscopically classified sample. the photometric pipeline described in this paper produces the calibrated fluxes and associated uncertainties used in the cosmological parameter analysis by employ... | first cosmology results using type ia supernovae from the dark energy survey: photometric pipeline and light-curve data release |
we present 888 visual-wavelength spectra of 122 nearby type ii supernovae (sne ii) obtained between 1986 and 2009, and ranging between 3 and 363 days post-explosion. in this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of sne ii... | type ii supernova spectral diversity. i. observations, sample characterization, and spectral line evolution |
the recent identification of a candidate very massive (70 m⊙) black hole (bh) is at odds with our current understanding of stellar winds and pair-instability supernovae. we investigate alternate explanations for this system by searching the bpass v2.2 stellar and population synthesis models for those that match the obs... | weighing in on black hole binaries with bpass: lb-1 does not contain a 70 m⊙ black hole |
we present a full-fledged analysis of brans-dicke cosmology with a cosmological constant and cold dark matter (bd-$\lambda$cdm for short). we extend the scenarios where the current cosmological value of the bd-field is restricted by the local astrophysical domain to scenarios where that value is fixed only by the cosmo... | brans-dicke cosmology with a $\\lambda$- term: a possible solution to $\\lambda$cdm tensions |
collective neutrino oscillations are critical to determine the neutrino flavor content, which has striking impacts on core-collapse supernovae or compact binary merger remnants. it is a challenging many-body problem that so far has been mainly studied at the mean-field approximation. we use a setup that captures the re... | many-body effects of collective neutrino oscillations |
we present at2020mrf (srge j154754.2+443907), an extra-galactic (z = 0.1353) fast blue optical transient (fbot) with a rise time of tg,rise = 3.7 days and a peak luminosity of mg,peak = -20.0. its optical spectrum around peak shows a broad (v ~ 0.1c) emission feature on a blue continuum (t ~ 2 × 104 k), which bears a s... | the x-ray and radio loud fast blue optical transient at2020mrf: implications for an emerging class of engine-driven massive star explosions |
we provide an end-to-end exploration of a distinct modified gravitational theory in jordan-brans-dicke (jbd) gravity, from an analytical and numerical description of the background expansion and linear perturbations, to the nonlinear regime captured with a hybrid suite of n -body simulations, to the cosmological constr... | testing gravity on cosmic scales: a case study of jordan-brans-dicke theory |
observations of individual massive stars, super-luminous supernovae, gamma-ray bursts, and gravitational wave events involving spectacular black hole mergers indicate that the low-metallicity universe is fundamentally different from our own galaxy. many transient phenomena will remain enigmatic until we achieve a firm ... | x-shooting ullyses: massive stars at low metallicity. i. project description |
we discuss the dark gauge boson emission from neutron stars via nucleon-nucleon bremsstrahlung. through the rigorous treatment of the effective field theory prescription and the thermal effect, we derive the relevant couplings of dark gauge bosons to hadrons in medium. as a specific example, the u(1)b−l gauge boson sce... | dark gauge boson production from neutron stars via nucleon-nucleon bremsstrahlung |
evidence is mounting that recent multiwavelength detections of fast blue optical transients (fbots) in star-forming galaxies comprise a new class of transients, whose origin is yet to be understood. we show that hydrogen-rich collapsing stars that launch relativistic jets near the central engine can naturally explain t... | shocked jets in ccsne can power the zoo of fast blue optical transients |
neutrino self-interactions in a dense neutrino gas can induce collective neutrino flavor conversions. fast neutrino flavor conversions (ffcs), one of the collective neutrino conversion modes, potentially change the dynamics and observables in core-collapse supernovae and binary neutron star mergers. in cases without ne... | effects of energy-dependent scatterings on fast neutrino flavor conversions |
observations of the extragalactic (z = 0.0141) transient at 2018cow established a new class of energetic explosions shocking a dense medium, producing luminous emission at millimeter and submillimeter wavelengths. here we present detailed millimeter- through centimeter-wave observations of a similar transient, ztf 20ac... | luminous millimeter, radio, and x-ray emission from ztf 20acigmel (at 2020xnd) |
dust associated with various stellar sources in galaxies at all cosmic epochs remains a controversial topic, particularly whether supernovae (sne) play an important role in dust production. we report evidence of dust formation in the cold, dense shell behind the ejecta-circumstellar medium (csm) interaction in the type... | newly formed dust within the circumstellar environment of snia-csm 2018evt |
in this work, we show that the cold new early dark energy (cold nede) model in its original form can solve both the hubble tension and the s 8 tension without adding any new ingredients at the fundamental level. so far, it was assumed that the trigger field in the cold nede model is completely subdominant. however, rel... | cold new early dark energy pulls the trigger on the h 0 and s 8 tensions: a simultaneous solution to both tensions without new ingredients |
the process of unstable mass transfer in a stellar binary can result in either a complete merger of the stars or successful removal of the donor envelope leaving a surviving more compact binary. luminous red novae (lrne) are the class of optical transients believed to accompany such merger/common envelope events. past ... | light-curve model for luminous red novae and inferences about the ejecta of stellar mergers |
we present a velocity-dispersion-based mass calibration of the south pole telescope sunyaev-zel'dovich effect survey (spt-sz) galaxy cluster sample. using a homogeneously selected sample of 100 cluster candidates from 720 deg2 of the survey along with 63 velocity dispersion (σ v ) and 16 x-ray y x measurements of sampl... | mass calibration and cosmological analysis of the spt-sz galaxy cluster sample using velocity dispersion σ vand x-ray y x measurements |
we examine whether the hubble tension, the mismatch between early and late measurements of h0, can be alleviated by ultralight scalar fields in the early universe, and we assess its plausibility within uv physics. since their energy density needs to rapidly redshift away, we explore decays to massless fields around the... | ultralight scalar decay and the hubble tension |
the standard model coherent elastic neutrino-nucleus scattering (ceνns) cross section is subject to nuclear form factor uncertainties, mainly driven by the root-mean-square radius of the neutron density distribution. motivated by coherent phases i-iii and future multi-ton direct detection dark matter searches, we evalu... | impact of form factor uncertainties on interpretations of coherent elastic neutrino-nucleus scattering data |
we use microwave temperature maps from two seasons of data from the atacama cosmology telescope at 146 ghz, together with the "constant mass" cmass galaxy sample from the baryon oscillation spectroscopic survey to measure the kinematic sunyaev-zel'dovich (ksz) effect over the redshift range z =0.4 - 0.7 . we use galaxy... | evidence for the kinematic sunyaev-zel'dovich effect with the atacama cosmology telescope and velocity reconstruction from the baryon oscillation spectroscopic survey |
the hot intra-cluster medium (icm) permeating galaxy clusters and groups is not pristine, as it has been continuously enriched by metals synthesised in type ia (snia) and core-collapse (sncc) supernovae since the major epoch of star formation (z ≃ 2-3). the cluster/group enrichment history and mechanisms responsible fo... | radial metal abundance profiles in the intra-cluster medium of cool-core galaxy clusters, groups, and ellipticals |
mergers of black hole (bh) and neutron star (ns) binaries are expected to be observed by gravitational wave observatories in the coming years. until now, ligo has only set an upper limit on this merger rate. bh-ns binaries are expected to merge in isolation, as their formation is suppressed in star clusters by the mass... | black hole-neutron star mergers from triples |
we construct a new equation of state (eos) for numerical simulations of core-collapse supernovae and neutron-star mergers based on an extended relativistic mean-field model with a small symmetry energy slope l, which is compatible with both experimental nuclear data and recent observations of neutron stars. the new eos... | effects of symmetry energy on the equation of state for simulations of core-collapse supernovae and neutron-star mergers |
we study the possibility of using csi[na] scintillators as an advantageous target for the detection of coherent elastic neutrino-nucleus scattering (cenns), using the neutrino emissions from the sns spallation source at oak ridge national laboratory. the response of this material to low-energy nuclear recoils like thos... | coherent neutrino-nucleus scattering detection with a csi[na] scintillator at the sns spallation source |
we present optical observations of supernova sn 2014c, which underwent an unprecedented slow metamorphosis from h-poor type ib to h-rich type iin over the course of one year. the observed spectroscopic evolution is consistent with the supernova having exploded in a cavity before encountering a massive shell of the prog... | metamorphosis of sn 2014c: delayed interaction between a hydrogen poor core-collapse supernova and a nearby circumstellar shell |
kozai-lidov (kl) oscillations in hierarchical triple systems have found application to many astrophysical contexts, including planet formation, type ia supernovae, and supermassive black hole dynamics. the period of these oscillations is known at the order-of-magnitude level, but dependences on the initial mutual incli... | timescales of kozai-lidov oscillations at quadrupole and octupole order in the test particle limit |
context. with growing evidence for the existence of very massive stars at subsolar metallicity, there is an increased need for corresponding stellar evolution models.aims: we present a dense model grid with a tailored input chemical composition appropriate for the large magellanic cloud (lmc).methods: we use a one-dime... | the evolution of rotating very massive stars with lmc composition |
aims: we present a comprehensive x-ray study of the population of supernova remnants (snrs) in the large magellanic cloud (lmc). using primarily xmm-newton observations, we conduct a systematic spectral analysis of lmc snrs to gain new insight into their evolution and the interplay with their host galaxy.methods: we co... | the population of x-ray supernova remnants in the large magellanic cloud |
motivated by the recent high-precision measurements of cosmic rays by several new-generation experiments, we have carried out a detailed study to understand the observed energy spectrum and composition of cosmic rays with energies up to about 1018 ev. our study shows that a single galactic component with subsequent ene... | cosmic-ray energy spectrum and composition up to the ankle: the case for a second galactic component |
host galaxy properties provide strong constraints on the stellar progenitors of superluminous supernovae. by comparing a sample of 19 low-redshift (z < 0.3) superluminous supernova hosts to galaxy populations in the local universe, we show that sub-solar metallicities seem to be a requirement. all superluminous supe... | superluminous supernova progenitors have a half-solar metallicity threshold |
extremely metal-poor (emp) stars in the milky way (mw) allow us to infer the properties of their progenitors by comparing their chemical composition to the metal yields of the first supernovae. this method is most powerful when applied to mono-enriched stars, i.e. stars that formed from gas that was enriched by only on... | descendants of the first stars: the distinct chemical signature of second-generation stars |
using an isolated milky way-mass galaxy simulation, we compare results from nine state-of-the-art gravito-hydrodynamics codes widely used in the numerical community. we utilize the infrastructure we have built for the agora high-resolution galaxy simulations comparison project. this includes the common disk initial con... | the agora high-resolution galaxy simulations comparison project. ii. isolated disk test |
flavor-specific scalar bosons exist in various standard model extensions and couple to a single generation of fermions via a global flavor symmetry breaking mechanism. given this strategy, we propose a mev flavor-specific scalar model in dimension-5 operator series, which explains the muon g — 2 anomaly and proton radi... | probing the flavor-specific scalar mediator for the muon (g — 2) deviation, the proton radius puzzle and the light dark matter production |
ngc 253 hosts the nearest nuclear starburst. previous observations show a region rich in molecular gas, with dense clouds associated with recent star formation. we used the atacama large submillimeter/millimeter array (alma) to image the 350 ghz dust continuum and molecular line emission from this region at 2 pc resolu... | forming super star clusters in the central starburst of ngc 253 |
the large neutrino density in the deep interior of core-collapse supernovae and compact binary merger remnants makes neutrino flavor evolution nonlinear because of the coherent forward scattering of neutrinos among themselves. under the assumption of spherical symmetry, we model neutrino decoupling from matter in an id... | neutrino decoupling is altered by flavor conversion |
a redshift tomography of the pantheon type ia supernovae (snia) data focusing on the best fit value of the absolute magnitude m and/or hubble constant h0 in the context of λ cdm indicates a local variation (z ≲0.2 ) at 2 σ level, with respect to the best fit of the full dataset. if this variation is not due to a statis... | hints of a local matter underdensity or modified gravity in the low z pantheon data |
determining the level of chemical homogeneity in open clusters is of fundamental importance in the study of the evolution of star-forming clouds and that of the galactic disk. yet limiting the initial abundance spread in clusters has been hampered by difficulties in obtaining consistent spectroscopic abundances for dif... | the chemical homogeneity of open clusters |
rapidly spinning, strongly magnetized protoneutron stars (“millisecond protomagnetars”) are candidate central engines of long-duration gamma-ray bursts (grbs), superluminous supernovae (slsne), and binary neutron star mergers. magnetar birth may be accompanied by the fallback of stellar debris, lasting for seconds or l... | effects of fallback accretion on protomagnetar outflows in gamma-ray bursts and superluminous supernovae |
this paper presents a short review on the current state of sn ia progenitor origin. type ia supernova explosions (meaning thermonuclear disruption of a white dwarf) are observed to be widely diverse in peak luminosity, lightcurve width and shape, spectral features, and host stellar population environment. in the last d... | type ia supernova sub-classes and progenitor origin |
the massive neutron star (ns) or black hole (bh) accretion disk resulting from ns-ns or ns-bh mergers is dense in neutrinos. we present the first study on the role of angular distributions in the neutrino flavor conversion above the remnant disk. in particular, we focus on "fast" pairwise conversions whose rate depends... | fast neutrino conversions: ubiquitous in compact binary merger remnants |
we present a simulation of the formation of the earliest population ii stars, starting from cosmological initial conditions and ending when metals created in the first supernovae are incorporated into a collapsing gas cloud. this occurs after a supernova blast-wave collides with a nearby mini-halo, inducing further tur... | the first population ii stars formed in externally enriched mini-haloes |
galactic outflows are observed everywhere in star-forming disk galaxies and are critical for galaxy formation. supernovae (sne) play the key role in driving the outflows, but there is no consensus as to how much energy, mass, and metal they can launch out of the disk. we perform 3d, high-resolution hydrodynamic simulat... | quantifying supernovae-driven multiphase galactic outflows |
the origin of the baryon asymmetry of the universe (bau) and the nature of dark matter are two of the most challenging problems in cosmology. we propose a scenario in which the gravitational collapse of large inhomogeneities at the quark-hadron epoch generates both the baryon asymmetry and dark matter in the form of pr... | a common origin for baryons and dark matter |
collective neutrino oscillations can potentially play an important role in transporting lepton flavor in astrophysical scenarios where the neutrino density is large, typical examples are the early universe and supernova explosions. it has been argued in the past that simple models of the neutrino hamiltonian designed t... | dynamical phase transitions in models of collective neutrino oscillations |
we present here the first of a series of papers aimed at better understanding the evolution and properties of giant molecular clouds (gmcs) in a galactic context. we perform high-resolution, three-dimensional arepo simulations of an interacting galaxy inspired by the well-observed m51 galaxy. our fiducial simulations i... | simulations of the star-forming molecular gas in an interacting m51-like galaxy |
electron capture on nuclei plays an essential role in the dynamics of several astrophysical objects, including core-collapse and thermonuclear supernovae, the crust of accreting neutron stars in binary systems and the final core evolution of intermediate-mass stars. in these astrophysical objects, the capture occurs at... | electron capture in stars |
we decompose pantheon + type ia supernovae (sn) in hemispheres on the sky finding angular variations up to 4 km /s /mpc , corresponding to a statistical significance up to 1.9 σ , in the hubble constant h0 both in the sh0es redshift range 0.0233 <z <0.15 and in extended redshift ranges. the variations are driven ... | anisotropic distance ladder in pantheon+supernovae |
axion-like particles (alps) decaying into photons are known to affect a wide range of astrophysical and cosmological observables. in this study we focus on alps with masses in the kev-mev range and lifetimes between 104 and 1013 seconds, corresponding to decays between the end of big bang nucleosynthesis and the format... | cosmological constraints on decaying axion-like particles: a global analysis |
in the past five years, the number of known double neutron stars (dnss) in the milky way has roughly doubled. we argue that the observed sample can be split into three distinct subpopulations based on their orbital characteristics: (i) short-period, low-eccentricity binaries; (ii) wide binaries; and (iii) short-period,... | double neutron star populations and formation channels |
we test the possible dipole anisotropy of the finslerian cosmological model and the other three dipole-modulated cosmological models, i.e. the dipole-modulated λcdm, wcdm and chevallier-polarski-linder (cpl) models, by using the recently released pantheon sample of sne ia. the markov chain monte carlo (mcmc) method is ... | constraining the anisotropy of the universe with the pantheon supernovae sample |
we present a modified version of the l-galaxies2020 semi-analytic model of galaxy evolution, which includes significantly increased direct metal enrichment of the circumgalactic medium (cgm) by supernovae (sne). these more metal-rich outflows do not require increased mass-loading factors, in contrast to some other gala... | l-galaxies 2020: the evolution of radial metallicity profiles and global metallicities in disc galaxies |
the observed rapid cooling of the neutron star (ns) located at the center of the supernova remnant cassiopeia a (cas a) can be explained in the minimal ns cooling scenario. this consequence may be changed if there exists an extra cooling source, such as axion emission. in this work, we study the cas a ns cooling in the... | limit on the axion decay constant from the cooling neutron star in cassiopeia a |
in environments with high dense neutrino gases, such as in core-collapse supernovae, the neutrinos can experience collective neutrino oscillation due to their self-interactions. in particular, fast flavor conversion driven by the crossings in the neutrino angular distribution can affect explosion mechanism, nucleosynth... | nonlinear evolution of fast neutrino flavor conversion in the preshock region of core-collapse supernovae |
the origin of the high-energy astrophysical neutrinos discovered by icecube remains largely unknown. multi-messenger studies have indicated that the majority of these neutrinos come from gamma-ray-dark sources. choked-jet supernovae (cjsne), which are supernovae powered by relativistic jets stalled in stellar materials... | high-energy neutrinos from choked-jet supernovae: searches and implications |
stripped-envelope core-collapse supernovae can be divided into two broad classes: the common type ib/c supernovae (sne ib/c), powered by the radioactive decay of 56ni, and the rare superluminous supernovae (slsne), most likely powered by the spin-down of a magnetar central engine. up to now, the intermediate regime bet... | luminous supernovae: unveiling a population between superluminous and normal core-collapse supernovae |
fast neutrino flavor conversion can occur in core-collapse supernovae or compact binary merger remnants when nonforward collisions are also at play, and neutrinos are not fully decoupled from matter. this work aims to shed light on the conditions under which fast flavor conversion is enhanced or suppressed by collision... | enhancement or damping of fast neutrino flavor conversions due to collisions |
explosive phenomena such as supernova remnant shocks and solar flares have demonstrated evidence for the production of relativistic particles. interest has therefore been renewed in collisionless shock waves and magnetic reconnection as a means to achieve such energies. although ions can be energized during such phenom... | stochastic electron acceleration during spontaneous turbulent reconnection in a strong shock wave |
cold dark matter explains a wide range of data on cosmological scales. however, there has been a steady accumulation of evidence for discrepancies between simulations and observations at scales smaller than galaxy clusters. one promising way to affect structure formation on small scales is a relatively strong coupling ... | constraints and consequences of reducing small scale structure via large dark matter-neutrino interactions |
nuclear isomers are populated in the rapid neutron capture process (r process) of nucleosynthesis. the r process may cover a wide range of temperatures, potentially starting from several tens of gk (several mev) and then cooling as material is ejected from the event. as the r-process environment cools, isomers can free... | sensitivity of neutron-rich nuclear isomer behavior to uncertainties in direct transitions |
we use six tilted spatially flat and untilted nonflat dark energy cosmological models in analyses of south pole telescope polarization (sptpol) cosmic microwave background (cmb) data, alone and in combination with planck 2015 cmb data and non-cmb data, namely, the pantheon type ia supernovae apparent magnitudes, a coll... | using spt polarization, planck 2015, and non-cmb data to constrain tilted spatially-flat and untilted nonflat λ cdm , xcdm, and ϕ cdm dark energy inflation cosmologies |
by comparing the properties of red supergiant (rsg) supernova (sn) progenitors to those of field rsgs, it has been claimed that there is an absence of progenitors with luminosities l above log (l/l⊙) > 5.2. this is in tension with the empirical upper luminosity limit of rsgs at log (l/l⊙) = 5.5, a result known as th... | the `red supergiant problem': the upper luminosity boundary of type ii supernova progenitors |
the past ten years have opened up a new parameter space in time-domain astronomy with the discovery of transients defying our understanding of how stars explode. these extremes of the transient paradigm represent the brightest—called superluminous supernovae—and the fastest—known as fast blue optical transients—of the ... | observational properties of extreme supernovae |
context. the post-main-sequence evolution of massive stars is very sensitive to many parameters of the stellar models. key parameters are the mixing processes, the metallicity, the mass-loss rate, and the effect of a close companion.aims: we study the change in the red supergiant (rsg) lifetimes, the tracks in the hert... | impact of mass-loss on the evolution and pre-supernova properties of red supergiants |
direct dark matter detection experiments will soon be sensitive to neutrinos from astrophysical sources, including the sun, the atmosphere, and supernovae, which will set an important benchmark and open a new window into neutrino physics and astrophysics. the detection of these neutrinos will be complementary to accele... | neutrino physics with dark matter detectors |
type ia supernovae are thought to be the result of a thermonuclear runaway in carbon/oxygen white dwarfs, but it is uncertain whether the explosion is triggered by accretion from a non-degenerate companion star or by a merger with another white dwarf. observations of a supernova immediately following the explosion prov... | no signature of ejecta interaction with a stellar companion in three type ia supernovae |
despite the many efforts, our theoretical understanding of the ultimate nature of the dark energy component of the universe still lags well behind the astounding experimental evidence achieved from the increasingly sophisticated observational tools at our disposal. while the canonical possibility is a strict cosmologic... | dynamical vacuum energy in the expanding universe confronted with observations: a dedicated study |
context. we present a large homogeneous set of stellar parameters and abundances across a broad range of metallicities, involving 13 classical dwarf spheroidal (dsph) and ultra-faint dsph (ufd) galaxies. in total, this study includes 380 stars in fornax, sagittarius, sculptor, sextans, carina, ursa minor, draco, reticu... | neutron-capture elements in dwarf galaxies. iii. a homogenized analysis of 13 dwarf spheroidal and ultra-faint galaxies |
we construct new equations of state for baryons at sub-nuclear densities for the use in core-collapse supernova simulations. the abundance of various nuclei is obtained together with thermodynamic quantities. the formulation is an extension of the previous model, in which we adopted the relativistic mean field theory w... | supernova equations of state including full nuclear ensemble with in-medium effects |
we perform two- (2d) and three-dimensional (3d) hydrodynamics simulations of convective oxygen-shell burning that takes place deep inside a massive progenitor star of a core-collapse supernova. using a one-dimensional (1d) stellar evolution code, we first calculate the evolution of massive stars with an initial mass of... | one-, two-, and three-dimensional simulations of oxygen-shell burning just before the core collapse of massive stars |
we investigate the generalized cubic covariant galileon model, a kinetically driven dark energy model within the horndeski class of theories. the model extends the cubic covariant galileon by including power laws of the field derivatives in the k-essence and cubic terms which still allow for tracker solutions. we study... | phenomenology of the generalized cubic covariant galileon model and cosmological bounds |
in view of the recent measurement of h0 from the hubble space telescope and supernova h0 for the equation of state (sh0es) team, we explore the possibility of existence of a negative cosmological constant [anti-de sitter (ads) vacua in the dark energy sector] in the universe. in this regard, we consider quintessence fi... | do cosmological observations allow a negative λ? |
in contrast to regular core-collapse supernovae, explosions of rapidly rotating massive stars can develop jets, fast collimated outflows directed along the rotational axis. depending on the rate of rotation and the magnetic field strength before collapse as well as on possible mechanisms amplifying the magnetic field, ... | nucleosynthesis in jet-driven and jet-associated supernovae |
point defects in the binary group-iv monochalcogenide monolayers of sns, snse, ges, and gese are investigated using density functional theory calculations. several stable configurations are found for oxygen defects, however, we give evidence that these materials are less prone to oxidation than phosphorene, with which ... | vacancies and oxidation of two-dimensional group-iv monochalcogenides |
we report the first measurement of low-energy proton-capture cross sections of <mml:mmultiscripts>xe 124 </mml:mmultiscripts> in a heavy-ion storage ring. <mml:mmultiscripts>xe124 </mml:mmultiscripts> 54 + ions of five different beam energies between 5.5 and 8 amev were stored to collide with a ... | approaching the gamow window with stored ions: direct measurement of 124xe (p ,γ ) in the esr storage ring |
while it is clear that type ia supernovae (sne) are the result of thermonuclear explosions in c/o white dwarfs (wds), a great deal remains uncertain about the binary companion that facilitates the explosive disruption of the wd. here, we present a comprehensive analysis of a large, unique data set of 127 sne ia with ex... | ztf early observations of type ia supernovae. ii. first light, the initial rise, and time to reach maximum brightness |
context. gaia data release 2 (dr2) provides a unique all-sky catalogue of 550 737 variable stars, of which 151 761 are long-period variable (lpv) candidates with g variability amplitudes larger than 0.2 mag (5-95% quantile range). about one-fifth of the lpv candidates are mira candidates, the majority of the rest are s... | gaia data release 2. the first gaia catalogue of long-period variable candidates |
we extract cosmological information from the anisotropic power-spectrum measurements from the recently completed baryon oscillation spectroscopic survey (boss), extending the concept of clustering wedges to fourier space. making use of new fast-fourier-transform-based estimators, we measure the power-spectrum clusterin... | the clustering of galaxies in the completed sdss-iii baryon oscillation spectroscopic survey: cosmological implications of the fourier space wedges of the final sample |
spectroscopic surveys of the galaxy reveal that its disc stars exhibit a spread in [α/fe] at fixed [fe/h], manifest at some locations as a bimodality. the origin of these diverse, and possibly distinct, stellar populations in the galactic disc is not well understood. we examine the fe and α-element evolution of 133 mil... | the origin of diverse α-element abundances in galaxy discs |
neutrinos are densely populated deep inside the core of massive stars after their gravitational collapse to produce supernova explosions and form compact stars such as neutron stars and black holes. it has been considered that they may change their flavor identities through so-called fast-pairwise conversions induced b... | linear analysis of fast-pairwise collective neutrino oscillations in core-collapse supernovae based on the results of boltzmann simulations |
in this work we explore an alternative phenomenological model to chaplygin gas proposed by hova et al. (int j mod phys d 26:1750178, 2017), consisting on a modification of a perfect fluid, to explain the dynamics of dark matter and dark energy at cosmological scales immerse in a flat or curved universe. adopting proper... | cosmological constraints on alternative model to chaplygin fluid revisited |
neutrino-neutrino refraction in dense media can cause self-induced flavor conversion triggered by collective run-away modes of the interacting flavor oscillators. the growth rates were usually found to be of order a typical vacuum oscillation frequency δ m2/2e. however, even in the simple case of a νe beam interacting ... | self-induced neutrino flavor conversion without flavor mixing |
half of the heavy elements including all actinides are produced in r-process nucleosynthesis, whose sites and history remain a mystery. if continuously produced, the interstellar medium is expected to build-up a quasi-steady state of abundances of short-lived nuclides (with half-lives ≤100 my), including actinides prod... | abundance of live 244pu in deep-sea reservoirs on earth points to rarity of actinide nucleosynthesis |
we present results from general-relativistic (gr) three-dimensional (3d) core-collapse simulations with approximate neutrino transport for three nonrotating progenitors (11.2, 15, and 40 m ⊙) using different nuclear equations of state (eoss). we find that the combination of progenitor’s higher compactness at bounce and... | correlated signatures of gravitational-wave and neutrino emission in three-dimensional general-relativistic core-collapse supernova simulations |
the regulation of the baryonic content in dwarf galaxies is a long-standing problem. supernovae (sne) are supposed to play a key role in forming large-scale galactic winds by removing important amounts of gas from galaxies. sne are efficient accelerators of non-thermal particles, so-called cosmic rays (crs), which can ... | cosmic ray feedback from supernovae in dwarf galaxies |
context. the remnants of core-collapse supernovae (sne) are probes of the physical processes associated with their parent sne.aims: here we aim to explore to which extent the remnant keeps memory of the asymmetries that develop stochastically in the neutrino-heating layer due to hydrodynamic instabilities (e.g., convec... | the fully developed remnant of a neutrino-driven supernova. evolution of ejecta structure and asymmetries in snr cassiopeia a |
observations restrict the parameter space of holographic dark energy (hde) so that a turning point in the hubble parameter h(z) is inevitable. concretely, cosmic microwave background, baryon acoustic oscillations and type ia supernovae (sne) data put the turning point in the future, but removing sne results in an obser... | a critique of holographic dark energy |
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