Neutrinos from Type-II Supernovae and the Neutrino-Driven Supernova Mechanism1
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Supernova Neutrinos in the Proto-Neutron Star Cooling Phase and Nuclear Matter
TAUP 2019 IOP Publishing Journal of Physics: Conference Series 1468 (2020) 012089 doi:10.1088/1742-6596/1468/1/012089 Supernova neutrinos in the proto-neutron star cooling phase and nuclear matter Ken’ichiro Nakazato1 and Hideyuki Suzuki2 1 Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan 2 Faculty of Science & Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan E-mail: [email protected] Abstract. A proto-neutron star (PNS) is a newly formed compact object in a core collapse supernova. Using a series of phenomenological equations of state (EOS), we have systematically investigated the neutrino emission from the cooling phase of a PNS. The numerical code utilized in this study follows a quasi-static evolution of a PNS solving the general-relativistic stellar structure with neutrino diffusion. As a result, the cooling timescale evaluated from the neutrino light curve is found to be long for the EOS models with small neutron star radius and large effective mass of nucleons. It implies that extracting properties of a PNS (such as mass and radius) and the nuclear EOS is possible by a future supernova neutrino observation. 1. Introduction Core collapse supernovae, which are the spectacular death of massive stars, emit an enormous amount of neutrinos. In the case of SN1987A, a few tens of events were actually detected [1, 2, 3] and contributed to confirm the standard scenario for supernova neutrino emission. Although the neutron star formed in SN1987A has not yet been observed, its mass estimations had been attempted by using the neutrino event number [4, 5]. -
A Magnetar Model for the Hydrogen-Rich Super-Luminous Supernova Iptf14hls Luc Dessart
A&A 610, L10 (2018) https://doi.org/10.1051/0004-6361/201732402 Astronomy & © ESO 2018 Astrophysics LETTER TO THE EDITOR A magnetar model for the hydrogen-rich super-luminous supernova iPTF14hls Luc Dessart Unidad Mixta Internacional Franco-Chilena de Astronomía (CNRS, UMI 3386), Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile e-mail: [email protected] Received 2 December 2017 / Accepted 14 January 2018 ABSTRACT Transient surveys have recently revealed the existence of H-rich super-luminous supernovae (SLSN; e.g., iPTF14hls, OGLE-SN14-073) that are characterized by an exceptionally high time-integrated bolometric luminosity, a sustained blue optical color, and Doppler- broadened H I lines at all times. Here, I investigate the effect that a magnetar (with an initial rotational energy of 4 × 1050 erg and 13 field strength of 7 × 10 G) would have on the properties of a typical Type II supernova (SN) ejecta (mass of 13.35 M , kinetic 51 56 energy of 1:32 × 10 erg, 0.077 M of Ni) produced by the terminal explosion of an H-rich blue supergiant star. I present a non-local thermodynamic equilibrium time-dependent radiative transfer simulation of the resulting photometric and spectroscopic evolution from 1 d until 600 d after explosion. With the magnetar power, the model luminosity and brightness are enhanced, the ejecta is hotter and more ionized everywhere, and the spectrum formation region is much more extended. This magnetar-powered SN ejecta reproduces most of the observed properties of SLSN iPTF14hls, including the sustained brightness of −18 mag in the R band, the blue optical color, and the broad H I lines for 600 d. -
Nucleosynthesis
Nucleosynthesis Nucleosynthesis is the process that creates new atomic nuclei from pre-existing nucleons, primarily protons and neutrons. The first nuclei were formed about three minutes after the Big Bang, through the process called Big Bang nucleosynthesis. Seventeen minutes later the universe had cooled to a point at which these processes ended, so only the fastest and simplest reactions occurred, leaving our universe containing about 75% hydrogen, 24% helium, and traces of other elements such aslithium and the hydrogen isotope deuterium. The universe still has approximately the same composition today. Heavier nuclei were created from these, by several processes. Stars formed, and began to fuse light elements to heavier ones in their cores, giving off energy in the process, known as stellar nucleosynthesis. Fusion processes create many of the lighter elements up to and including iron and nickel, and these elements are ejected into space (the interstellar medium) when smaller stars shed their outer envelopes and become smaller stars known as white dwarfs. The remains of their ejected mass form theplanetary nebulae observable throughout our galaxy. Supernova nucleosynthesis within exploding stars by fusing carbon and oxygen is responsible for the abundances of elements between magnesium (atomic number 12) and nickel (atomic number 28).[1] Supernova nucleosynthesis is also thought to be responsible for the creation of rarer elements heavier than iron and nickel, in the last few seconds of a type II supernova event. The synthesis of these heavier elements absorbs energy (endothermic process) as they are created, from the energy produced during the supernova explosion. Some of those elements are created from the absorption of multiple neutrons (the r-process) in the period of a few seconds during the explosion. -
Nuclear Physics and Core Collapse Supernovae
Nuclear physics and core collapse supernovae K. Langanke1 1 Institut for Fysik og Astronomi, Arhusº Universitet DK-8000 Arhusº C, Denmark Nuclear physics plays an essential role in the dynamics of a collapsing massive stars, a type II supernova. Recent advances in nuclear many-body theory allow now to reliably calculate the stellar weak-interaction processes involving nuclei. The most important process is the electron capture on ¯nite nuclei with mass numbers A > 55. It is found that the respective capture rates, derived from modern many-body models, di®er noticeably from previous, more phenomenological estimates. This leads to signi¯cant changes in the stellar trajectory during the supernova explosion, as has been found in state-of-the-art supernova simulations. The present article is based on a more detailed and extended manuscript appearing in Lecture Notes in Physics [1]. PACS numbers: CORE COLLAPSE SUPERNOVAE - THE GENERAL PICTURE At the end of hydrostatic burning, a massive star consists of concentric shells that are the remnants of its previous burning phases (hydrogen, helium, carbon, neon, oxygen, silicon). Iron is the ¯nal stage of nuclear fusion in hydrostatic burning, as the synthesis of any heavier element from lighter elements does not release energy; rather, energy must be used up. If the iron core, formed in the center of the massive star, exceeds the Chandrasekhar mass limit of about 1.44 solar masses, electron degeneracy pressure cannot longer stabilize the core and it collapses starting what is called a type II supernova. In its aftermath the star explodes and parts of the iron core and the outer shells are ejected into the Interstellar Medium. -
Neutrinos from Core-Collapse Supernovae and Binary Neutron Star Mergers
Neutrinos from core-collapse supernovae and binary neutron star mergers Maria Cristina Volpe Astroparticules et Cosmologie (APC), Paris, France Sun core-collapse Supernovae McLaughlin Perego et al, 2014 accretion disks around black holes or neutron star mergers remnants Solar neutrino observations Vacuum averaged oscillations pep MSW solution 7Be 8B ν Survival Probability e Borexino, Nature 512 (2014) ν Neutrino Energy (MeV) Vacuum-averaged oscillations versus MSW suppression of high energy 8B neutrinos. Energy production of low mass main sequence stars confirmed — pp reaction chain. Future measurement of CNO neutrinos - main energy production in massive main sequence stars. The Mikheev-Smirnov-Wolfenstein effect Neutrinos interact with matter and undergo resonant adiabatic flavor conversion. Wolfenstein PRD (1978) Mikheev, Smirnov(1985) hmat = p2GF ⇢e mean-field approximation matter basis flavour basis ~ ν2 =νe ν , ν ν ν ~ ν2 µ τ e 2 ~ ν 1 =νµ ν~ 1 Effective mass Effective vacuum ν1 MSW resonance DENSITY 2 ∆m˜ /4E i✓˙M h⌫ = − − neutrino hamiltonian in the matter basis i✓˙ ∆m˜ 2/4E ✓ M ◆ ✓˙M Resonance condition : Adiabaticity : γ = | 2 | << 1 h h 0 ∆m˜ /4E ⌫,11 − ⌫,22 ⇡ Also in supernovae, in accretion disks around compact objects, in the Earth and in the Early Universe (BBN epoch) Heavy elements nucleosynthesis Two main mechanisms at the origin of elements heavier than iron : s-process (s-slow) and r-process (r-rapid). Double peak structures at the first A=90, the second A=130 and third A=190 peaks due to both the s-process and the r-process. The r-process sites : a longstanding question The r-process : neutron-capture is fast compared to half-lives of neutron-rich unstable nuclei. -
Gigantic Japanese Detector Seeks Supernova Neutrinos Tracing the History of Exploding Stars Is a Goal of the Revamped Super-Kamiokande
NEWS IN FOCUS ASAHI SHIMBUN/GETTY Observations by the Super-Kamiokande neutrino detector have forced theorists to amend the standard model of particle physics. PHYSICS Gigantic Japanese detector seeks supernova neutrinos Tracing the history of exploding stars is a goal of the revamped Super-Kamiokande. BY DAVIDE CASTELVECCHI weight. These data will help astronomers to detector much better at distinguishing between better understand the history of supernovae different types, or ‘flavours’, of neutrino, as well leven thousand giant orange eyes in the Universe — but the neutrinos that the as their antiparticles, antineutrinos. confront the lucky few who have explosions emit have been difficult to detect. In 1987, the Kamiokande detector, Super-K’s entered the Super-Kamiokande under- “Every 2–3 seconds, a supernova goes off smaller predecessor, detected the first neutri- Eground neutrino observatory in Japan — by somewhere in the Universe, and it produces nos from a supernova. The dozen neutrinos far the largest neutrino detector of its kind in 1058 neutrinos,” says Masayuki Nakahata, came from Supernova 1987A, which occurred the world. A chance to see these light sensors who heads the Super-K, an international col- in the Large Magellanic Cloud, a small galaxy is rare because they are usually submerged in laboration led by Japan and the United States. that orbits the Milky Way. Head experimenter 50,000 tonnes of purified water. But a major With the upgrade, the detector should be able Masatoshi Koshiba shared the 2002 Nobel revamp of Super-K that was completed in to count a few of these ‘relic’ neutrinos every physics prize partly for that discovery. -
Astroparficle,Physics,, With,Mev,Neutrinos
University(of(Virginia,(HEP(Seminar,(April(21st(2015( Astropar(cle,physics,, with,MeV,neutrinos, Shunsaku(Horiuchi(( (Center(for(Neutrino(Physics,(Virginia(Tech)( Image(credit:(NASA/ESA( Contents, • IntroducJon:(why(astrophysical(neutrinos(now?( • Topic(1:(Supernova(neutrinos( – GalacJc(events:(rich(physics(and(astronomy( – Detectability(beyond(GalacJc(events( • Topic(2:(Dark(maPer(neutrinos( – Two(searches,(two(constraints( • Summary( UVa,(April(21st(2015( Shunsaku(Horiuchi((Virginia(Tech)( 2( Neutrinos,as,messenger,par(cles Neutrinos(are(great(messenger(parJcles:( • allow(us(to(see(opJcally(thick((to(photons)(regions( • experience(liPle(aPenuaJon(through(cosmic(space( • travel(in(straight(lines( Source Neutrinos gamma(rays( Cosmic(raysCosmic(rays( MagneJc(field UVa,(April(21st(2015 Shunsaku(Horiuchi((Virginia(Tech) 3( Neutrino,detec(on:,Cherenkov,, Use(the(Cherenkov(light(to(reconstruct(the(original(neutrino( ν" IceCube( Eν >(10(GeV( Muon(range(increases( the(effecJve(volume(( lepton( e( Du>a,et,al,,PRD,(2001),, SuperVKamiokande( Eν(>(few(MeV(( Volume(~(50(kton(of(water( Volume(~(1(Gton(of(ice( UVa,(April(21st(2015( Shunsaku(Horiuchi((Virginia(Tech)( 4( Neutrino,sources, RadioacJve(decay( Sun((x1)( Nuclear( Supernova((x1)( reactors( ParJcle( Astrophysical( accelerator( accelerator( Likely' Cosmic(background( Atmospheric( +(others?( UVa,(April(21st(2015(Shunsaku(Horiuchi((IPMU)((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((Shunsaku(Horiuchi((Virginia(Tech)( -
Supernovae and Neutron Stars
Outline of today’s lecture Lecture 17: •Finish up lecture 16 (nucleosynthesis) •Supernovae •2 main classes: Type II and Type I Supernovae and •Their energetics and observable properties Neutron Stars •Supernova remnants (pretty pictures!) •Neutron Stars •Review of formation http://apod.nasa.gov/apod/ •Pulsars REVIEWS OF MODERN PHYSICS, VOLUME 74, OCTOBER 2002 The evolution and explosion of massive stars S. E. Woosley* and A. Heger† Department of Astronomy and Astrophysics, University of California, Santa Cruz, California 95064 T. A. Weaver Lawrence Livermore National Laboratory, Livermore, California 94551 (Published 7 November 2002) Like all true stars, massive stars are gravitationally confined thermonuclear reactors whose composition evolves as energy is lost to radiation and neutrinos. Unlike lower-mass stars (M Շ8M᭪), however, no point is ever reached at which a massive star can be fully supported by electron degeneracy. Instead, the center evolves to ever higher temperatures, fusing ever heavier elements until a core of iron is produced. The collapse of this iron core to a neutron star releases an enormous amount of energy, a tiny fraction of which is sufficient to explode the star as a supernova. The authors examine our current understanding of the lives and deaths of massive stars, with special attention to the relevant nuclear and stellar physics. Emphasis is placed upon their post-helium-burning evolution. Current views regarding the supernova explosion mechanism are reviewed, and the hydrodynamics of supernova shock propagation and ‘‘fallback’’ is discussed. The calculated neutron star masses, supernova light curves, and spectra from these model stars are shown to be consistent with observations. -
Pre-Supernova Evolution of Massive Stars
Chapter 12 Pre-supernova evolution of massive stars We have seen that low- and intermediate-mass stars (with masses up to ≈ 8 M⊙) develop carbon- oxygen cores that become degenerate after central He burning. As a consequence the maximum core temperature reached in these stars is smaller than the temperature required for carbon fusion. During the latest stages of evolution on the AGB these stars undergo strong mass loss which removes the remaining envelope, so that their final remnants are C-O white dwarfs. The evolution of massive stars is different in two important ways: • They reach a sufficiently high temperature in their cores (> 5×108 K) to undergo non-degenerate carbon ignition (see Fig. 12.1). This requires a certain minimum mass for the CO core after central He burning, which detailed evolution models put at MCO−core > 1.06 M⊙. Only stars with initial masses above a certain limit, often denoted as Mup in the literature, reach this criti- cal core mass. The value of Mup is somewhat uncertain, mainly due to uncertainties related to mixing (e.g. convective overshooting), but is approximately 8 M⊙. Stars with masses above the limit Mec ≈ 11 M⊙ also ignite and burn fuels heavier than carbon until an Fe core is formed which collapses and causes a supernova explosion. We will explore the evolution of the cores of massive stars through carbon burning, up to the formation of an iron core, in the second part of this chapter. • For masses M >∼ 15 M⊙, mass loss by stellar winds becomes important during all evolution phases, including the main sequence. -
Modelling a Type-II Supernova
Modelling a Type-II Supernova F.S. Nobels, J. Ubink, H.W. de Vries Guided by: Prof. Dr. O. Scholten January 21, 2015 Abstract A code was created for modelling the hydrodynamics of a type-II core-collapse supernova. Whereas the typical supernova explosion was not observed due to instability of the code, various succesful tests were performed on a more simple, earth-like atmosphere. Observing various shockwave and equilibrium phenomena in the earth-like atmosphere, it can be concluded that the hydrodynamics of the supernova model probably work correctly. Possible improvements to the model would consist of adding radiative transfer and a neutrino-heating mechanism. A code as been written for the former, but this has not been incorporated in the model in a working manner yet. Contents 1 Introduction 4 1.1 Star evolution and mass criterion . 5 1.2 Mechanism of the type II supernova . 5 1.3 Stellar composition . 6 1.3.1 Neutron star core model . 6 1.3.2 Red giant-like star . 6 1.4 Mean molecular mass . 7 2 Physics of supernovae 8 2.1 Pressure, energy, and temperature . 8 2.2 Luminosity . 9 2.3 Decay processes . 11 2.4 Opacity . 12 2.5 Blast Waves . 13 3 Creating a numerical model 15 3.1 Basic assumptions . 15 3.1.1 Spherical symmetry . 15 3.1.2 Gas composition . 15 3.1.3 Homogeneous distributions . 15 3.2 Discretizations . 15 3.2.1 Stellar shells . 15 3.2.2 Shell mass continuity . 16 3.2.3 Time discretization . 18 3.2.4 Variable time step . -
Neutrinos from Supernovae Detecting the Diffuse Supernova Neutrino Background
Neutrino Probes of Supernovae Shunsaku Horiuchi (Uni of Tokyo, IPMU) IPMU ACP Seminar, 14th May 2009 Introduction Thermal neutrinos from supernovae Detecting the diffuse supernova neutrino background Non-thermal neutrinos from supernovae Gamma-ray burst context (Magnetic stars) Summary Shunsaku Horiuchi (IPMU) 2 The Dream of Neutrino Astronomy “If [there are no new forces] -- one can conclude that there is no practically possible way of observing the neutrino.” Bethe&Peierls, Nature (1934) “The title is more of an expression of hope than a description of the book’s contents....the observational horizon of neutrino astrophysics may grow...perhaps in a time as short as one or two decades.” Bahcall, Neutrino Astrophysics (1989) We now have the technology to detect neutrinos! And we know neutrino sources exist. Neutrinos are unique messengers in astrophysics. It is timely to study astrophysical neutrinos Shunsaku Horiuchi (IPMU) 3 Some neutrino sources Radioactive Sun (x1) decay Nuclear Supernova (x1) reactors Particle Astrophysical accelerator soon accelerator Cosmic Atmospheric background Shunsaku Horiuchi (IPMU) 4 Supernova neutrinos are Many MeV neutrinos [thermal] Core-collapse of massive star (x1) How are neutron stars and black holes formed? GeV – TeV neutrinos [non-thermal] Supernova, supernova remnants, and gamma-ray bursts Particle acceleration and hadronic interactions? > TeV neutrinos [non-thermal] Gamma-ray bursts? What are the origins of high-energy cosmic rays? Each gives us valuable information Shunsaku -
Supernova Neutrinos Lecture
Lecture III Supernova Neutrinos A Neutron Star is Born 1500 km Shock wave ~1051ergs 3X107 km B. E. ~2-3 1053 ergs 10 km proto-neutron star: t~1-2 s 100 km Epochs in the evolution of a neutron star. Prakash et al., Phys. Rept. (1990) Traversing the Phase Diagram T (MeV) T 170 QGP 50 Novel High Density Phases: 10 Hyperons, Kaons Quark Matter .. Nuclear Matter Nuclei Neutron Stars 930 ~1200 ? ? µΒ (MeV) Traversing the Phase Diagram T (MeV) T 170 QGP 50 Novel High Density Phases: 10 Hyperons, Kaons Quark Matter .. Nuclear Collapse Matter Nuclei Neutron Stars 930 ~1200 ? ? µΒ (MeV) Traversing the Phase Diagram T (MeV) T 170 QGP PNS Evolution 50 Novel High Density Phases: 10 Hyperons, Kaons Quark Matter .. Nuclear Collapse Matter Nuclei Neutron Stars 930 ~1200 ? ? µΒ (MeV) Supernova Neutrinos Future: 3 ×1053 ergs = 1058 × 20 MeV Neutrinos Can detect ~10,000 neutrinos from galactic supernova Past: SN 1987a: ~ 20 neutrinos ..in support of supernova theory 28 np~ 6.7 × 10 =number of protons per ton Mtons= detector mass in tons -44 2 σref ~ 2 × 10 cm = weak cross-section D ~ 10 kpc = distance to supernova Supernova Neutrinos Future: 3 ×1053 ergs = 1058 × 20 MeV Neutrinos Can detect ~10,000 neutrinos from galactic supernova Past: SN 1987a: ~ 20 neutrinos ..in support of supernova theory 28 np~ 6.7 × 10 =number of protons per ton Mtons= detector mass in tons -44 2 σref ~ 2 × 10 cm = weak cross-section D ~ 10 kpc = distance to supernova Dimensional Analysis with G, M, and R R 2GM Compactness: s = 0.3 0.4 R Rc2 − GM m 1 R Binding Energy: n = s m = 140 200 MeV R 2 R n − R3 R R R 3/2 τFree Fall = = 80 ms − GM c R 1000 km s R R R τHydro = τFree Fall = c − c R s s Weak Interaction Time-Scales 2 2 2 2 4GF me E 44 E 2 σweak = 2 =1.7 10− 2 cm π me × me 2 1 5 me λν (T )= =3 10 2 cm nσweak(T ) × T 2 2 2 R 4 R T τ = = 10− s Diffusion cλ 10 km m2 ν e Protoneutron Star Evolution Initial state of the PNS.