We give an update on our OZ Survey to find more extremely metal poor (EMP) stars with [Fe/H] < —3 dex through mining the database of the Hamburg/ESO Survey. We present the most extreme such stars we have found from -̂ 1550 moderate resolution follow up spectra. One of these, HE1424—0241, has highly anomalous abundance ratios not seen in any previously known halo giant, with very deficient Si, mo...

We present a multiwavelength analysis of a compact group of galaxies infalling at high speed into the dynamically young cluster Abell 1367. Peculiar morphologies and unusually high Hα emission are associated with two giant galaxies and at least ten dwarfs/extragalactic HII regions, making this group the region with the highest density of star formation activity ever observed in the local cluste...

We present the results of a study of the morphology of the dwarf galaxy population in Abell 868, a rich, intermediate redshift (z=0.154) cluster which has a galaxy luminosity function with a steep faint-end slope (α=–1.26±0.05). A statistical background subtraction method is employed to study the B −R colour distribution of the cluster galaxies. This distribution suggests that the galaxies cont...

Extremely large optical Kerr non-linearities (n2) and (n4) were measured in two closed degenerate two-level transitions in the caesium D2 line when a probe and a coupling laser simultaneously probed and coupled the hyperfine structure in an atomic beam. The magnitude of the measured non-linearities in both transitions were found to be a function of the coupling laser intensity and of the probe ...

The small number of oblate-shaped nuclei found in nature, compared with the many prolate nuclei, is a surprising feature of nuclear structure, which seems to be related to the strength of the nuclear spin-orbit interaction [1]. Furthermore, with increasing angular momentum, the collective rotation of an oblate shape, about an axis perpendicular to its axis of symmetry, is disadvantaged relative...

The negation map can be used to speed up the computation of elliptic curve discrete logarithms using either the baby-step giant-step algorithm (BSGS) or Pollard rho. Montgomery’s simultaneous modular inversion can also be used to speed up Pollard rho when running many walks in parallel. We generalize these ideas and exploit the fact that for any two elliptic curve points X and Y , we can effici...

The giant galaxies located at the centers of cluster cooling flows are frequently sites of vigorous star formation. In some instances, star formation appears to have been triggered by the galaxy’s radio source. The colors and spectral indices of the young populations are generally consistent with short duration bursts or continuous star formation for durations ≪ 1 Gyr, which is less than the pr...

Galaxies above redshift 1 can be very clumpy, with irregular morphologies dominated by star complexes as large as 2 kpc and as massive as a few ×10 or 10 M⊙. Their co-moving densities and rapid evolution suggest that most present-day spirals could have formed through a clumpy phase. The clumps may form by gravitational instabilities in gas-rich turbulent disks; they do not appear to be separate...

We consider the large N spectrum of the quantum mechanical hamiltonian of two hermitean matrices coupled via a Yang-Mills interaction. In a framework where one of the matrices is treated exactly and the other is treated as a creation operator impurity, the difference equation associated with the YangMills interaction is derived and solved exactly for two impurities. In this case, the full strin...

Abstract The covariant particle-vibration coupling model within the time blocking approximation is employed to supplement the Relativistic Random Phase Approximation (RRPA) with coupling to collective vibrations. The Bethe-Salpeter equation in the particle-hole channel with an energy dependent residual particle-hole (p-h) interaction is formulated and solved in the shell-model Dirac basis as we...