Minerals explained 26: The garnets     

R.J. King 《Geology Today》1999,15(1):34-37

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Graphite     

R.J. King 《Geology Today》2006,22(2):71-77

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Young stars in the Galactic Centre: a potential intermediate-mass star origin     

L. M. Dray  A. R. King  M. B. Davies 《Monthly notices of the Royal Astronomical Society》2006,372(1):31-44

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Aligning spinning black holes and accretion discs     

A. R. King  S. H. Lubow  G. I. Ogilvie  J. E. Pringle 《Monthly notices of the Royal Astronomical Society》2005,363(1):49-56

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The population of black widow pulsars     

A. R. King  M. E. Beer  D. J. Rolfe  K. Schenker  J. M. Skipp 《Monthly notices of the Royal Astronomical Society》2005,358(4):1501-1504

We consider the population of black widow pulsars (BWPs). The large majority of these are members of globular clusters. For minimum companion masses  ≲0.1 M_⊙  , adiabatic evolution and consequent mass loss under gravitational radiation appear to provide a coherent explanation of all observable properties. We suggest that the group of BWPs with minimum companion masses  ≳0.1 M_⊙  are systems relaxing to equilibrium after a relatively recent capture event. We point out that all binary millisecond pulsars (MSPs) with orbital periods   P ≲ 10  h are BWPs (our line of sight allows us to see the eclipses in 10 out of 16 cases). This implies that recycled MSPs emit either in a wide fan beam or a pencil beam close to the spin plane. Simple evolutionary ideas favour a fan beam.  相似文献   

Type Ia supernovae and remnant neutron stars     

A. R. King  J. E. Pringle  D. T. Wickramasinghe 《Monthly notices of the Royal Astronomical Society》2001,320(3):L45-L48

On the basis of the current observational evidence, we put forward the case that the merger of two CO white dwarfs produces both a Type Ia supernova explosion and a stellar remnant, the latter in the form of a magnetar. The estimated occurrence rates raise the possibility that many, if not most, Type Ia supernovae might result from white dwarf mergers.  相似文献   

The short-period supersoft source in M31     

A. R. King  J. P. Osborne  K. Schenker 《Monthly notices of the Royal Astronomical Society》2002,329(2):L43-L46

We show that the recently discovered short period supersoft source in M31 is probably a progenitor of a magnetic cataclysmic variable (CV). The white dwarf spins asynchronously because of the current high accretion rate. However its fieldstrength is typical of an AM Herculis system, which is what it will ultimately become. We discuss the relevance of this system to CV evolution, and its relation to some particular CVs with special characteristics.  相似文献   

The circumnuclear X-ray reflectors in NGC 1068 and the Circinus galaxy     

Stefano Bianchi    Giorgio Matt  Kazushi Iwasawa 《Monthly notices of the Royal Astronomical Society》2001,322(3):669-680

The ASCA and BeppoSAX spectra of the Circinus galaxy and NGC 1068 are analysed and compared with photoionization models based on cloudy . In the case of Circinus, a single, mildly ionized reflector can account for the line spectrum, while in NGC 1068 at least three different reflectors (with different ionization states) are needed. We suggest that the reflector in Circinus and the low ionized one in NGC 1068 are the inner and visible part of the material responsible for the X-ray absorption. With this assumption, we estimate for the inner radius of the absorber a value of 0.2 pc for Circinus and of a few parsecs for NGC 1068.  相似文献   

The ultraviolet line spectrum of the soft X-ray transient XTE J1118+480: a CNO-processed core exposed     

C. A. Haswell  R. I. Hynes  A. R. King  K. Schenker 《Monthly notices of the Royal Astronomical Society》2002,332(4):928-932

We compare ultraviolet (UV) spectra of the recent soft X-ray transients XTE J1118+480 and XTE J1859+226. The emission line strengths in XTE J1118+480 strongly suggest that the accreting material has been CNO processed. We show that this system must have come into contact with a secondary star of about 1.5 M_⊙, and an orbital period ∼15 h, very close to the bifurcation value at which the nuclear and angular momentum loss time-scales are similar. Subsequent evolution to the current period of 4.1 h was driven by angular momentum loss. In passing through a period of 7.75 h the secondary star would have shown essentially normal surface abundances. XTE J1118+480 could thus represent a slightly later evolutionary stage of A0620-00. We briefly discuss the broad Ly α absorption wings in XTE J1118+480.  相似文献   

Amplification of primordial magnetic fields by anisotropic gravitational collapse     

Emma J. King  Peter Coles 《Monthly notices of the Royal Astronomical Society》2006,365(4):1288-1294

If a magnetic field is frozen into a plasma that undergoes spherical compression, then the magnetic field B varies with the plasma density ρ according to   B ∝ρ^2/3  . In the gravitational collapse of cosmological density perturbations, however, quasi-spherical evolution is very unlikely. In anisotropic collapses the magnetic field can be a much steeper function of gas density than in the isotropic case. We investigate the distribution of amplifications in realistic gravitational collapses from Gaussian initial fluctuations using the Zel'dovich approximation. Representing our results using a relation of the form   B ∝ρ^α  , we show that the median value of α can be much larger than the value  α= 2/3  resulting from spherical collapse, even if there is no initial correlation between magnetic field and principal collapse directions. These analytic arguments go some way towards understanding the results of numerical simulations.  相似文献