Exklusionsindividualität

Hillebrandt, Frank

doi:10.1007/978-3-663-10016-4

Cited by 13 publications

(12 citation statements)

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“…In ECSNe the low explosion energy and the extremely rapid outward expansion of SN shock and postshock layer (all of which are linked to the steep density decline outside of the degenerate core) are detrimental to the possibility of large NS kicks. 1 Our results have important implications for the discussion of the Crab SN and its stellar origin, for which an O-Ne-Mg core progenitor has been proposed (Nomoto et al 1982;Hillebrandt 1982). Such a connection seems to be compatible with the He-rich chemical composition of the nebula and a small amount of ejected iron-group material (Nomoto et al 1982;MacAlpine & Satterfield 2008;Wanajo et al 2011;Smith 2013), a small ejecta mass (Davidson & Fesen 1985;Fesen et al 1997), low kinetic energy (Yang & Chevalier 2015;Kitaura et al 2006;Dessart et al 2006;Fischer et al 2010;Radice et al 2017), and the characteristics of the light curve (Tominaga et al 2013;Smith 2013).…”

Section: Introductionmentioning

confidence: 81%

Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova

Gessner

Janka

2018

ApJ

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Neutron stars (NSs) obtain kicks of typically several 100 km s −1 at birth. The gravitational tugboat mechanism can explain these kicks as consequences of asymmetric mass ejection during the supernova (SN) explosion. Support for this hydrodynamic explanation is provided by observations of SN remnants with associated NSs, which confirm the prediction that the bulk of the explosion ejecta, in particular chemical elements between silicon and the iron group, are dominantly expelled in the hemisphere opposite to the direction of the NS kick. Here, we present a large set of twoand three-dimensional explosion simulations of electron-capture SNe, considering explosion energies between ∼3×10 49 erg and ∼1.6×10 50 erg. We find that the fast acceleration of the SN shock in the steep density gradient delimiting the O-Ne-Mg core of the progenitor enables such a rapid expansion of neutrino-heated matter that the growth of neutrino-driven convection freezes out quickly in a highmode spherical harmonics pattern. Since the corresponding momentum asymmetry of the ejecta is very small and the gravitational acceleration by the fast-expanding ejecta abates rapidly, the NS kick velocities are at most a few km s −1 . The extremely low core compactness of O-Ne-Mg-core progenitors therefore favors hydrodynamic NS kicks much below the ∼160 km s −1 measured for the Crab pulsar. This suggests either that the Crab Nebula is not the remnant of an electron-capture SN, but of a lowmass iron-core progenitor, or that the Crab pulsar was not accelerated by the gravitational tug-boat mechanism but received its kick by a non-hydrodynamic mechanism such as, e.g., anisotropic neutrino emission.

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Section: Introductionmentioning

confidence: 81%

Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova

Gessner

Janka

2018

ApJ

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“…Using the resulting distribution of the gas flow, the chemical evolution is solved by taking into account the lifetimes of stars, and using modern nucleosynthesis predictions to compute the yields of stars of different masses. In particular, for stars with masses 0.8 < M/M < 8 the yields were taken from Renzini & Voli (1981), while for stars with 8 < M/M < 10 the yields from Hillebrandt (1982) were assumed. For SN II progenitors with 10 < M/M < 40 we adopted the yields of Woosley & Weaver (1995) and extrapolated these for M > 40M/M .…”

Section: Star Formation and Chemical Evolutionmentioning

confidence: 99%

Coupled spheroid and black hole formation, and the multifrequency detectability of active galactic nuclei and submillimetre sources

Archibald

Dunlop

Jiménez

et al. 2002

Monthly Notices of the Royal Astronomical Society

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We use a simple model of spheroid formation to explore the relationship between the creation of stars and dust in a massive protogalaxy and the growth of its central black hole. This model predicts that submillimetre luminosity peaks after only ≃0.2 Gyr. However, without a very massive seed black hole, Eddington‐limited growth means that a black hole mass of 109 M⊙, and hence very luminous active galactic nuclei (AGN) activity, cannot be produced until >0.5 Gyr after the formation of the first massive stars in the halo. The model thus predicts a time‐lag between the peak of submillimetre luminosity and AGN luminosity in a massive protoelliptical of a few times 108 yr. For a formation redshift z≃ 5, this means that powerful AGN activity is delayed until z≃ 3.5, by which time star formation in the host is ≃90 per cent complete, and submillimetre luminosity has declined to ≃25 per cent of its peak value. This provides a natural explanation for why successful submillimetre detections of luminous radio galaxies are largely confined to z > 2.5. Conversely the model also predicts that while all high‐redshift luminous submillimetre‐selected sources should contain an active (and growing) black hole, the typical luminosity of the AGN in such objects is ≃1000 times smaller than that of the most powerful AGN. This is consistent with the almost complete failure to detect submillimetre selected galaxies with existing X‐ray surveys. Finally, the model yields a black hole–spheroid mass ratio, which evolves rapidly in the first Gyr, but asymptotes to ≃0.001–0.003 in agreement with results at low redshift. This ratio arises not because the AGN terminates star formation, but because fuelling of the massive black hole is linked to the total mass of gas available for star formation in the host.

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“…We consider production of secondary N via CNO shell burning in the envelopes of massive stars (m > 8 M⊙) following the case B of Talbot & Arnett (1973) (100% conversion of the envelope C and O into N). For stars in the mass range 8 − 10 M⊙, the nucleosynthesis prescriptions are those suggested by Hillebrandt (1982Hillebrandt ( ,1985. The yields from Type II SNe with progenitors with mass between 10 and 40 M⊙ are from Weaver & Woosley (1993) and Woosley & Weaver (1995), using a value of the 12 C(α, γ) 16 O reaction rate which is 1.7 times the Caughlan & Fowler (1988) value.…”

Section: The Chemical Evolutionmentioning

confidence: 99%

Formation and evolution of elliptical galaxies and QSO activity

Friaça¹,

Terlevich

1998

Monthly Notices of the Royal Astronomical Society

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We present the results of a numerical code that combines multi-zone chemical evolution with 1-D hydrodynamics to follow in detail the evolution and radial behaviour of gas and stars during the formation of elliptical galaxies. We use the model to explore the links between the evolution and formation of elliptical galaxies and QSO activity. The knowledge of the radial gas flows in the galaxy allows us to trace metallicity gradients, and, in particular, the formation of a high-metallicity core in ellipticals. The high-metallicity core is formed soon enough to explain the metal abundances inferred in high-redshift quasars. The star formation rate and the subsequent feedback regulate the episodes of wind, outflow, and cooling flow, thus affecting the recycling of the gas and the chemical enrichment of the intergalactic medium. The evolution of the galaxy shows several stages, some of which are characterized by a complex flow pattern, with inflow in some regions and outflow in other regions. All models, however, exhibit during their late evolution a galactic wind at the outer boundary and, during their early evolution, an inflow towards the galaxy nucleus. The inner inflow evolution could explain the bolometric luminosity of a quasar lodged at the galaxy centre as well as the evolution of the QSO luminosity function.Comment: 19 pages, 9 figures, to be published in MNRA

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Exklusionsindividualität

Cited by 13 publications

References 0 publications

Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova

Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova

Coupled spheroid and black hole formation, and the multifrequency detectability of active galactic nuclei and submillimetre sources

Formation and evolution of elliptical galaxies and QSO activity

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