The Spin Periods and Rotational Profiles of Neutron Stars at Birth

By Christian D. Ott, Adam Burrows, T. Thompson, E. Livne, Rolf Walder. 2005

163 citations recorded by the source corpus.

We present results from an extensive set of one- and two-dimensional radiation-hydrodynamic simulations of the supernova core-collapse, bounce, and postbounce phases and focus on the proto-neutron star (PNS) spin periods and rotational profiles as a function of initial iron core angular velocity, degree of differential rotation, and progenitor mass. For the models considered, we find a roughly linear mapping between initial iron core rotation rate and PNS spin. The results indicate that the magnitude of the precollapse iron core angular velocities is the single most important factor in determining the PNS spin. Differences in progenitor mass and degree of differential rotation lead only to small variations in the PNS rotational period and profile. Based on our calculated PNS spins at ~200-300 ms after bounce and assuming angular momentum conservation, we estimate final neutron star rotation periods. We find periods of 1 ms and shorter for initial central iron core periods of ≲10 s. This is appreciably shorter than what previous studies have predicted and is in disagreement with current observational data from pulsar astronomy. After considering possible spin-down mechanisms that could lead to longer periods, we conclude that there is no mechanism that can robustly spin down a neutron star from ~1 ms periods to the "injection" periods of tens to hundreds of milliseconds observed for young pulsars. Our results indicate that, given current knowledge of the limitations of neutron star spin-down mechanisms, precollapse iron cores must rotate with periods of around 50-100 s to form neutron stars with periods generically near those inferred for the radio pulsar population.

Subfields: Astronomy and Astrophysics, Ocean Engineering, Oceanography

View Paper: https://www.semanticscholar.org/paper/6ef39c76e301e581a38ba9f2438c83f11d7540f3

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Ocean Engineering

In Oceanography

Citations in the corpus

Three-dimensional neutrino-driven supernovae: neutron star kicks, spins, and asymmetric ejection of nucleosynthesis products (2012, background): “It is possible that faster NS rotation requires the progenitor core to rotate (e.g., Heger et al. 2005; Ott et al. 2006).”
The Masses and Spins of Neutron Stars and Stellar-Mass Black Holes (2014, background): “In a similar vein, if newly-formed neutron stars are surrounded by a fallback accretion disk, early spin down via magnetic coupling may be another means of achieving rapid spin-down [137].”
MAGNETOROTATIONAL CORE-COLLAPSE SUPERNOVAE IN THREE DIMENSIONS (2014, background): “4s; Ott et al. 2006; Burrows et al. 2007) and an efficient process to rapidly amplify the likely weak 1 TAPIR, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125, USA, pmoesta@tapir.caltech.edu 2 Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU WPI),…”
Two-Dimensional Multiangle, Multigroup Neutrino Radiation-Hydrodynamic Simulations of Postbounce Supernova Cores (2008, background): “This rotation law enforces constant angular velocity on cylindrical shells and, for sensible choices ofA, reproduces qualitatively (Ott et al. 2006b) predictions from presupernova models that include rotation in a 1D fashion (Heger et al. 2000, 2005).”
Approximate Universal Relations for Neutron Stars and Quark Stars (2016, background): “newly-born stars that rotate differentially and are highly magnetized [454, 455].”
The Supernova Gamma-Ray Burst Connection (2006, background): “However, incorporation of approximate magnetic torques (Spruit, 2002) in single stars that evolve through a red giant phase gives too little rotation for GRBs (Heger et al., 2005), though just about the right amount for pulsars (Ott et al., 2005).”
Binary star progenitors of long gamma-ray bursts (2007, background): “…(Petrovic et al. 2005b; Hirschi et al. 2005), only models including magnetic fields are capable of reproducing the slow spins of young Galactic neutron stars (Heger et al. 2005; Ott et al. 2006) and white dwarfs (Suijs et al. 2007), due to the magnetic coreenvelope coupling during the giant stage.”
Supernova simulations from a 3D progenitor model - Impact of perturbations and evolution of explosion properties (2017, background): “…short neutron star birth periods of a few tens of milliseconds other than spin-up by the standing accretion shock instability (Blondin & Mezzacappa 2006; Guilet & Fernández 2014; Kazeroni et al. 2016) or the assumption of pre-collapse rotation rates of ∼100 s (Heger et al. 2005; Ott et al. 2006).”
The unusual X-ray emission of the short Swift GRB 090515: evidence for the formation of a magnetar? (2010, background): “(10) It has been suggested that the radii of proto-neutron stars may be as large as a few tens of kilometres (Ott et al. 2006), so in Fig.”
BLACK HOLE FORMATION IN FAILING CORE-COLLAPSE SUPERNOVAE (2010, methodology): “This is a variation on the rotation law commonly used in simulations of rotating core collapse (e.g., Ott et al. 2006), whereΩ(r) = j(r)r−2 is prescribed and the differential-rotation parameterA is set to some constant radius.”
Two-dimensional hydrodynamic core-collapse supernova simulations with spectral neutrino transport II. Models for different progenitor stars (2005, background): “Rotation of this size is probablyon the extreme side of what can be expected for the cores of “normal” supernovae, which are supposed to give birth to neutron stars with an initial period of 10 ms or more (see the discussions in Heger et al. 2005 and Ott et al. 2006).”
Simulations of Magnetically Driven Supernova and Hypernova Explosions in the Context of Rapid Rotation (2007, methodology): “We use the hybrid grid that we have employed in previous VULCAN/2D multidimensional radiation-hydrodynamics simulations (Ott et al. 2006; Dessart et al. 2006a, 2006b; Burrows et al. 2006, 2007).”