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Supernovae. Part II: the Aftermath UC Irvine UC Irvine Previously Published Works Title Supernovae. Part II: The aftermath Permalink https://escholarship.org/uc/item/9br465v7 Journal Reviews of Modern Physics, 55(2) ISSN 0034-6861 Author Trimble, V Publication Date 1983 DOI 10.1103/RevModPhys.55.511 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Supernovae. Part II: the aftermath Virginia Trimble Department ofPhysics, University of California, Irvine, California 92717 and Astronomy Program, University ofMaryland, College Park, Maryland 20742 Part 1 [Rev. Mod. Phys. 54, 1183 (1982)] explored stellar evolution leading up to supernovae and observa- tions and models of the events themselves. Part II addresses the aftermath: supernova remnants, products, and by-products, including nucleosynthesis, and the future of supernova research. Some of the important questions are: (1) How close is the association among supernova events, pulsar production, and remnant production? (2) Where does most of the energy from neutron star formation go? and (3) How do superno- vae interact with the rest of the universe, for instance in heating and stirring the interstellar medium, ac- celerating cosmmlc rays, and triggering or inhibiting star formation? CONTENTS C. Other massive stars 540 V. Supe rnova Remnants 511 D. Type I supernovae 540 A. The Crab Nebula 512 E. Other sites of nucleosynthesis 541 1. The inner nebula 512 1. Pregalactic and supermassive stars 541 2. fhe halo 513 2. Intermediate-mass stars 541 3. Models 514 3. Novae 542 B. Rates and types 514 F. Sites of the r and p processes 542 C. Ejection mechanics and energy 515 1. The r process 543 D. Mass and composition of ejecta 518 2. The p process 543 VI. Supe rnova By-products 519 G. Miscellanea galactica 543 A. Gravitational radiation 519 1. Turbulence and the stellar birthrate function 544 1. Binaries and asymmetric rotators 520 2. Galactic winds 544 2. Core collapse and pulsation 520 3. Infall 544 3. Pulsars 521 4. Back to the lab 544 B. Neutrinos 522 VIII. The Future of Supernova Research 545 C. Cosmic rays 523 A. Supernovae as a cosmological tool 545 1. Acceleration in the supernova explosion 524 1. Calibration of absolute luminosities 545 2. Acceleration in and around young supernova 2. Wishful thinking 546 remnants 524 B. Supernova searches 547 3. Acceleration by pulsars 525 1. Historical 547 4. Acceleration in the general interstellar medium 525 2. Photographic 547 D. Gamma rays 526 3. Automated and/or electronic searches 548 1. Bursts 526 C. Prob'ems entrusted to the next generation 549 2. Transients and hnes 526 Notes added in proof 550 3. Long-lived sources 527 Notes and corrections to Part 1 fRev. Mod. Phys 4. Everything else (Pooh-Bah models) 528 54, 1183 (1982)] 550 X rays 528 Notes added to Part II 551 1. The precursor pulse 528 Acknowledgments 552 2. Emission near maximum light 529 References 552 3. Everything else 529 a. Supernova remnants 529 b. Neutron stars 530 V. SUPERNOVA REMNANTS F. Heating and stirring of the interstellar medium (ISM) 530 1. Total energy supplied to the ISM 531 Supernovae as a class were born with their remnants in 2. Mechanism of energy input 531 place. By the time Baade and Zwicky (1934) separated 3. Specific features attributable to supernova effects 531 them off from the classical novae, the work of Barnard 4. Large-scale structure of the ISM 532 (1917, 1919) on Nova Per 1901 and Nova Aq] 1918 had 5. The local interstellar medium 532 established firmly within the astronomical folklore Supernova-induced star formation 533 1. Stars in general 533 (Russell, Dugan, and Stewart, 1927) the idea that an old 2. The solar system 533 nova ought to be surrounded by an expanding gas claud, H. Supernova-triggered galaxy formation 534 with expansion time scale equal to the time since the out- Neutron stars and pulsars 535 burst (Humason, 1935). The Crab nebula 535 The lore of supernova remnants (SNR's) is an impar- 2. Other pulsars 536 tant subject in its own right. These objects are among the 3. Other neutron stars 536 most conspicuous radio and x-ray sources in our own and 4. Statistics and models 537 "normal" 5. Sorting out the mess 537 other galaxies, and modeling them adequately VII. Nu cleosynthesis and Galactic Evolution 538 probes the frontiers of plasma astrophysics and the tech- A. The grand scheme 538 niques that must be used to understand the behavior of B. Massive population I stars (SN II progenitors) 539 active galaxies and other exotics. Reviews of Modern Physics, Vol. 55, No. 2, April 1983 Copyright Qc 1983 The American Physical Society 512 Virginia Trimble: Supernovae. Part II The standard reference has, for many years, been that virtually all the flux is pulsed at the period of NP 0532 by Woltjer (1972). More recent useful reviews include (Thompson et al., 1977a; Swanenburg et al., 1981; Gupta those of models by Chevalier (1982) and McKee (1982) et al., 1978). If the measured photon fluxes (about and those of observations and their interpretations that 6&(10 cm s ' above 35 MeV and 10 " cm s will appear in the IAU Symposium edited by Gorenstein above 500 GeV) are taken as upper limits to the inverse and Danziger (1983). The six:tions that follow, after a Compton fiux, then the average magnetic field remains brief historical nod at the Crab Nebula, focus on those as- constrained to & 3)& 10 G, essentially the equipartition pects of SNR's that help constrain models of supernova value, as noted by Fazio et al. (1971)and others. events and their interactions with the rest of the universe. At the low-energy end, far-infrared and millimeter These include the rates and types of supernovae in our fluxes and upper limits have now been reported by several own and other galaxies, the mechanism and energy of the groups (Werner et al., 1977; Harvey, Gatley, and Thron- ejection process, and the mass and composition of the ma- son, 1978; Wright et al., 1979, Glaccum et al., 1982). terial ejected. From 200 pm longward, these fit well onto an extrapola- tion of the radio spectrum, but the 60-, 100-, and 140-pm A. The Crab Nebula points (Glaccum et al., 1982) imply a modest infrared ex- cess, which the authors attribute to dust, behaving along This pineapple-shaped enigma (Rosse, 1844) is the only the lines modeled by Dwek and Werner (1981). The dust single object to have rated its own IAU Symposium 'temperature is about 40 K, reasonable for silicates ex- (Davies and Smith, 1971) without our living next to or in- posed to the radiation field of the nebula. Fluxes mea- side of it. Its remarkable list of firsts and near-firsts in- sured in seven 40X50" fields over the object show that cludes genuinely diffuse emission as opposed to an un- the dust is not piled up around the edges like swept-up in- resolved star cluster (Lassell, 1854), high-velocity emis- terstellar material. Rather, it is distributed more or less sion lines (Slipher, 1916), a radio source (Bolton and Stan- like the nonthermal radio emission. Given this distribu- ley, 1948) with polarization (Mayer, McCullough, and tion, the 2.6X10 Mo needed to make the infrared ex- Sloanaker, 1957) and a compact core (Hewish and Okoye, cess in the central 60" implies 2.4X10 Mo of dust for 1964), optical synchrotron radiation (Dombrovsky, 1954), the nebula as a whole (Glaccum and Harper, 1982). This an x-ray source (Bowyer et al., 1964) also polarized very nicely balances the modest heavy-element deficiency (Weisskopf et al., 1978), and an optical pulsar (Cocke, in the thermal gas, giving the inner nebula as a whole a Disney, and Taylor, 1969) with a changing period quite ordinary Population I abundance pattern, apart (Richards and Comella, 1969) and glitches (Boynton from the excess helium. et al., 1969). The continuum ultraviolet spectrum shows up clearly In the duodecade since IAU Symposium No. 46, the in both ANS and IUE data (Wu, 1981; Davidson et al., limelight has largely moved on to other objects. 1982). It confirmed earlier conclusions that line-of-sight Nevertheless, an assortment of more recent observations m reddening, E(B—V), is about 0. 5 and helped to pin has helped a bit to pin down what must be going on inside down the change in spectral index with frequency: the volume of the nebula and provided evidence for ap- Ii(v) ac with a=0.25 in the radio range, 0.43 in the preciable mass and energy outside the familiar outline. v, optical, O.S in the uv, and 1.1 in the x-ray region. The line-emitting gas, in comparison at least to that in 1. The inner nebula other young SNR's, continues to be relatively unexciting. Both ultraviolet (Davidson et al., 1982) and infrared The object which graces the covers of so many elemen- (Dennefeld and Andrillat, 1981) lines of carbon show that tary astronomy texts emits both continuum synchrotron the element is not significantly overabundant (C/O-l). radiation from a power-law distribution of relativistic Thus the only demonstrated abundance anomaly contin- electrons (and positrons?) within an ambient magnetic ues to be the enhancement of helium, which is, however, field and emission lines from & 1 M~ of gas near 10 K. considerable. Helium probably makes up about 80% of The former is seen from very low radio frequencies well the mass of line-emitting gas. He/H may be nonuniform into the gamma-ray region, the latter largely in the opti- over the nebula, with a relatively low value in the cal, near-uv, and near-ir.
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