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Supernova 1987A's Keyhole: A Long-lived Jet-pair in the Final Explosion Phase of Core-collapse Supernovae

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Research in Astronomy and Astrophysics 2024年第7期24卷 92-97页

作者： noam soker Department of Physics Technion

I further study the manner by which a pair of opposite jets shape the “keyhole” morphological structure of the core-collapse supernova(CCSN) SN 1997A, now the CCSN remnant(CCSNR) 1987A. By doing so, I strengthen the claim that the jittering-jet explosion mechanism accounts for most, likely all, CCSNe. The “keyhole” structure comprises a northern low-intensity zone closed with a bright rim on its front and an elongated low-intensity nozzle in the south. This rim-nozzle asymmetry is observed in some cooling flow clusters and planetary nebulae that are observed to be shaped by jets. I build a toy model that uses the planar jittering jets pattern, where consecutive pairs of jets tend to jitter in a common plane, implying that the accreted gas onto the newly born neutron star at the late explosion phase flows perpendicular to that plane. This allows for a long-lived jet-launching episode. This long-lasting jet-launching episode launches more mass into the jets that can inflate larger pairs of ears or bubbles,forming the main jets' axis of the CCSNR that is not necessarily related to a possible pre-collapse core rotation. I discuss the relation of the main jets' axis to the neutron star's natal kick velocity.

关键词： (stars:) supernovae: general (stars:) supernovae: individual (SN 1987A) ISM: supernova remnants stars: jets stars: massive

Imprints of the Jittering Jets Explosion Mechanism in the Morphology of the Supernova Remnant SNR 0540-69.3

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Research in Astronomy and Astrophysics 2022年第3期22卷 186-193页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I identify a point-symmetric structure in recently published VLT/MUSE velocity maps of different elements in a plane along the line of sight at the center of the supernova remnant SNR 0540-69.3,and argue that jittering jets that exploded this core collapse supernova shaped this point-symmetric *** four pairs of two opposite clumps that compose this point symmetric structure suggest that two to four pairs of jittering jets shaped the inner ejecta in this *** addition,intensity images of several spectral lines reveal a faint strip(the main jet-axis)that is part of this plane of jittering jets and its similarity to morphological features in a few other SNRs and in some planetary nebulae further suggests shaping by *** interpretation implies that in addition to instabilities,jets also mix elements in the ejecta of core collapse *** on the point-symmetric structure and under the assumption that jittering jets exploded this supernova,I estimate the component of the neutron star natal kick velocity on the plane of the sky to be■235 km s^(-1),and at an angle of■47°to the direction of the main jet-axis.I analyze this natal kick direction together with 12 other SNRs in the frame of the jittering jets explosion mechanism.

关键词： ISM:supernova remnants stars:jets (stars:)supernovae:general (stars:)supernovae:individual(SNR 0540-69.3)

Pre-explosion Helium Shell Flash in Type Ia Supernovae

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Research in Astronomy and Astrophysics 2022年第9期22卷 98-105页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I study the possibility that within the frame of the core degenerate(CD)scenario for type Ia supernovae(SNe Ia)the merger process of the core of the asymptotic giant branch(AGB)star and the white dwarf(WD)maintains an envelope mass of≈0.03 Mthat causes a later helium shell flash.I estimate the number of pre-explosion helium shell flash events to be less than a few per cent of all CD scenario SNe Ia.A helium shell flash while the star moves to the left on the HR diagram as a post-AGB star(late thermal pulse—LTP)or along the WD cooling track(very LTP—VLTP)causes the star to expand and become a“born again”AGB *** remnants exploding while still on the AGB form hydrogen-polluted peculiar SNe Ia,while an explosion inside an inflated born-again star results in an early flux excess in the light curve of the SN *** fraction of systems that might show an early flux excess due to LTP/VLTP is

关键词： stars:supernovae:general (stars:)white dwarfs (stars:)binaries(including multiple):close

Boosting Jittering Jets by Neutrino Heating in Core Collapse Supernovae

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Research in Astronomy and Astrophysics 2022年第9期22卷 77-87页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I estimate the energy that neutrino heating adds to the outflow that jets induce in the collapsing core material in core collapse supernovae(CCSNe), and find that this energy crudely doubles the energy that the jets deposit into the outer core. I consider the jittering jets explosion mechanism where there are several stochastic jet-launching episodes, each lasting for about 0.01–0.1 s. The collapsing core material passes through the stalled shock at about100 km and then slowly flows onto the proto-neutron star(NS). I assume that the proto-NS launches jittering jets,and that the jets break out from the stalled shock. I examine the boosting process by which the high-pressure gas inside the stalled shock, the gain region material, expands alongside the jets and does work on the material that the jets shock, the cocoon. This work is crudely equal to the energy that the original jets carry. I argue that the coupling between instabilities, stochastic rotation, magnetic fields, and jittering jets leads to most CCSN explosions. In other cases, the pre-collapse core is rapidly rotating and therefore ordered rotation replaces stochastic rotation and fixed jets replace jittering jets.

关键词： stars:supernovae:general stars:jets ISM:supernova remnants

The Role of Jets in Exploding Supernovae and in Shaping their Remnants

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Research in Astronomy and Astrophysics 2022年第12期22卷 28-52页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I review studies of core collapse supernovae(CCSNe) and similar transient events that attribute major roles to jets in powering most CCSNe and in shaping their ejecta. I start with reviewing the jittering jets explosion mechanism that I take to power most CCSN explosions. Neutrino heating does play a role in boosting the jets. I compare the morphologies of some CCSN remnants to planetary nebulae to conclude that jets and instabilities are behind the shaping of their ejecta. I then discuss CCSNe that are descendants of rapidly rotating collapsing cores that result in fixed-axis jets(with small jittering) that shape bipolar ejecta. A large fraction of the bipolar CCSNe are superluminous supernovae(SLSNe). I conclude that modeling of SLSN light curves and bumps in the light curves must include jets, even when considering energetic magnetars and/or ejecta interaction with the circumstellar matter(CSM). I connect the properties of bipolar CCSNe to common envelope jets supernovae(CEJSNe) where an old neutron star or a black hole spirals-in inside the envelope and then inside the core of a red supergiant. I discuss how jets can shape the pre-explosion CSM, as in Supernova 1987A, and can power pre-explosion outbursts(precursors)in binary system progenitors of CCSNe and CEJSNe. Binary interaction also facilitates the launching of postexplosion jets.

关键词： (stars:)supernovae:general ISM:supernova remnants stars:jets ISM:jets and outflows (stars:)binaries:general

A Pre-explosion Effervescent Zone for the Circumstellar Material in SN 2023ixf

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Research in Astronomy and Astrophysics 2023年第8期23卷 5-9页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I present the effervescent zone model to account for the compact dense circumstellar material(CSM)around the progenitor of the core collapse supernova(CCSN)SN *** effervescent zone is composed of bound dense clumps that are lifted by stellar pulsation and envelope convection to distances of≈tens×au,and then fall *** dense clumps provide most of the compact CSM mass and exist alongside the regular(escaping)wind.I crudely estimate that for a compact CSM within R_(CSM)≈30 au that contains M_(CSM)≈0.01 M_(⊙),the density of each clump is k_(b)≳3000 times the density of the regular wind at the same radius and that the total volume filling factor of the clumps is several *** clumps might cover only a small fraction of the CCSN photosphere in the first days post-explosion,accounting for the lack of strong narrow absorption *** long-lived effervescent zone is compatible with no evidence for outbursts in the years prior to the SN 2023ixf explosion and the large-amplitude pulsations of its progenitor,and it is an alternative to the CSM scenario of several-years-long high mass loss rate wind.

关键词： stars massive-stars mass-loss (stars:)supernovae general-(stars:)supernovae individual(SN 2023ixf)

Supernovae Ia in 2017:a long time delay from merger/accretion to explosion

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Science China(Physics,Mechanics & Astronomy) 2018年第4期61卷 7-16页

作者： noam soker Department of Physics Technion-lsrael Institute of TechnologyHaifa 32000Israel Guangdong Technion Israel Institute of Technology shantou 515063China

I use recent observational and theoretical studies of type Ia supernovae(SNe Ia) to further constrain the viable SN Ia scenarios and to argue that there must be a substantial time delay between the end of the merger of the white dwarf(WD) with a companion or the end of mass accretion on to the WD and its terminal explosion. This merger/accretion to explosion delay(MED) is required to allow the binary system to lead to a more or less spherical explosion and to prevent a pre-explosion ionizing radiation. Considering these recent results and the required MED, I conclude that the core degenerate scenario is somewhat more favorable over the other scenarios, followed by the double degenerate scenario. Although the single degenerate scenario is viable as well, it is less likely to account for common(normal) SN Ia. As all scenarios require substantial MED, the MED has turned from a disadvantage of the core degenerate scenario to a challenge that theory should overcome. I hope that the requirement for a MED will stimulate the discussion of the different SN Ia scenarios and the comparison of the scenarios to each other.

关键词： Ia 爆炸兼并延期生长时间 MED SN

Predicting Gravitational Waves from Jittering-jets-driven Core Collapse Supernovae

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Research in Astronomy and Astrophysics 2023年第12期23卷 1-6页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I estimate the frequencies of gravitational waves from jittering jets that explode core collapse supernovae(CCSNe)to crudely be 5–30 Hz,and with strains that might allow detection of Galactic *** jittering jets explosion mechanism(JJEM)asserts that most CCSNe are exploded by jittering jets that the newly born neutron star(NS)launches within a few *** to the JJEM,instabilities in the accreted gas lead to the formation of intermittent accretion disks that launch the jittering *** studies that did not include jets calculated the gravitational frequencies that instabilities around the NS emit to have a peak in the crude frequency range of 100–*** on a recent study,I take the source of the gravitational waves of jittering jets to be the turbulent bubbles(cocoons)that the jets inflate as they interact with the outer layers of the core of the star at thousands of kilometers from the *** lower frequencies and larger strains than those of gravitational waves from instabilities in CCSNe allow future,and maybe present,detectors to identify the gravitational wave signals of jittering *** of gravitational waves from local CCSNe might distinguish between the neutrino-driven explosion mechanism and the JJEM.

关键词： gravitational waves-stars neutron-stars black holes-(stars )supernovae general-stars jets

On the Nature of Jets from a Main Sequence Companion at the Onset of Common Envelope Evolution

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天文和天体物理学研究:英文版 2023年第9期23卷 12-19页

作者： noam soker Department of Physics TechnionHaifa3200003Israel

I consider a flow structure by which main sequence companions that enter a common envelope evolution(CEE)with giant stars might launch jets even when the accreted gas has a sub-Keplerian specific angular momentum.I first show that after a main sequence star enters the envelope of a giant star the specific angular momentum of the accreted gas is sub-Keplerian but still sufficiently large for the accreted gas to avoid two conical-like openings along the two opposite polar directions.I suggest that the high-pressure zone that the accreted gas builds around the main sequence equatorial plane accelerates outflows along these polar *** of the inflowing gas is deflected to the polar outflows,i.e.,two oppositely directed *** actual mass that the main sequence star accretes is only a small fraction,≈0.1,of the inflowing ***,the gravitational energy that this gas releases powers the inflow-outflow streaming of gas and adds energy to the common envelope *** flow structure might take place during a grazing envelope evolution if it occurs,during the early CEE and possibly in some post-CEE *** study increases the parameter space for main sequence stars to launch *** jets might shape some morphological features in planetary nebulae,add energy to mass removal in CEE and power some intermediate luminosity optical transients.

关键词： (stars )binaries(including multiple) close-stars jets-stars winds-outflows-(ISM )planetary nebulae general