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We present the first results of a detailed abundance analysis, based on VLT observations, of giant stars in the very metal-rich globular cluster NGC 6528. We will be able to tie the horizontal branch abundances (see e.g. Carretta et al. 2001) to those of the more luminous giants (see CMDs). For the very similar cluster NGC 6553 studies of different types of stars have yielded very disparate result
In this paper, the ongoing spectroscopic investigations of the plasma inside a fluorescent lamp at Lund Observatory is presented. The intensity of the spectral lines of neutral and singly ionized mercury and krypton in the electrode region in a fluorescent lamp are investigated, both as a function of current through the tube and time resolved during an AC cycle. The results show different dynamics
The present paper investigates and discusses the ability of the Hartmann test with a 4-aperture differential image motion monitor (DIMM) to measure the atmospheric primary aberrations which, in turn, can be used for the calculation of the atmospheric coherence time. Through performing numerical simulations, we show that the 4-aperture DIMM is able to measure the defocus and astigmatism terms corre
About a hundred dust impacts per day were detected during the first week in December 1995 by Galileo during its approach to Jupiter. These impacts were caused by submicrometer-sized particles that were just above the detection limit. After the closest approach to Io on 7 December, impacts of these small particles ceased. This effect is expected for dust grains emitted from Io that exit the field o
We have determined detailed elemental abundances and stellar ages for a sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge. Stars with sub-solar metallicities are all old and have enhanced alpha-element abundances - very similar to what is seen for local thick disk stars. The metal-rich stars on the other hand show a wide variety of stellar ages, ranging from 3-4 Gyr to 12
We discuss mass transfer in eccentric binaries containing a white dwarf and a neutron star (WD-NS binaries). We show that such binaries are produced from field binaries following a series of mass transfer episodes that allow the white dwarf to form before the neutron star. We predict the orbital properties of binaries similar to the observed WD-NS binary J1141+6545, and show that they will undergo
The evolution of the Solar neighbourhood is followed using a unique,magnitude complete and kinematically unbiased sample of 14,000 F, G, andK dwarfs. Metallicity, age, space motion and galactic orbits have beendetermined for all stars. The result is a detailed view of the complexevolution of the local Milky Way, which must be matched by any model forthe chemical and dynamical evolution of the Gala
Two UV lines of Fe II at 2507/2509 Å are extremely bright inspatially resolved HST/STIS spectra of dense gas condensations (the socalled Weigelt blobs) close to the central star of eta Carinae. Thelines also appear unresolved in HST/FOS spectra of the star AE And.Under normal conditions the lines should hardly be observable. Based onrecent studies of the formation of thelambdalambda2507/2509 lines
We investigate the structure and evolution of blue straggler stars, which were formed from direct stellar collisions between main-sequence stars in globular clusters. In particular, we look at the rotational evolution of the products of off-axis collisions. As found in previous work, such blue stragglers initially have too high an angular momentum to contract down to the main sequence. We consider
Vi följer en foton på dess färd genom världsrymden, från att den skapas i en avlägsen stjärna till att den landar på någons näthinna. Denna resa kan ta tusentals år. En del fotoner absorberas längs vägen, men just vår foton når hela vägen fram och gör att vi kan se vårt universum. Men även om fotonens resa slutar i ditt öga, så färdas informationen vidare till din hjärna.I denna visning utforskar Follow the journey of a single photon as it is produced in a distant star, before travelling across the vast expanse of space to land on someone's retina.This fulldome planetarium show explores some of the fascinating processes of the cosmos, from astrophysics to the biology of the eye and brain.
This paper presents new experimentally determined branching fractions and oscillator strengths (log gf) for lines originating from 17 levels belonging to 5 terms of the first excited odd configuration 4d(7)(D-4) 5p in Rh II. The intensity calibrated spectra of Rh II have been recorded with a Fourier transform spectrometer between 25000 and 45000 cm(-1) (2200-4000 angstrom). In this region, 49 line
Inspired by the flow description of su(N) colour calculations, we recently showed how to simplify the spinor-helicity formalism (at the algebra level two copies of complexified su(2)) by treating each Weyl spinor as part of a flow line with definite chirality and momentum. This formalism, dubbed the chirality-flow formalism, eliminates all non-trivial algebra from tree-level spinor-helicity calcul
We show that a generalized version of the holographic principle can be derived from the Hamiltonian description of information flow within a quantum system that maintains a separable state. We then show that this generalized holographic principle entails a general principle of gauge invariance. When this is realized in an ambient Lorentzian space-time, gauge invariance under the Poincaré group is
We discuss the associated cc¯ and l+l- pairs production in ultraperipheral heavy-ion collisions at high energies. Such a channel provides a novel probe for double-parton scattering (DPS) at small x enabling one to probe the photon density inside the nucleus. We have derived an analog of the standard central pp pocket formula and studied the kinematical dependence of the effective cross section. Ta
Herwig 7 is a general-purpose Monte Carlo generator of particle collisions comprising both hard perturbative as well as soft phenomenological physics. Herwig is therefore capable to describe the entire final state of hadronized particles in a collision event. A spacetime topology of a parton system entering hadronization is fully described and tested for the first time. A combination of informatio
We present the public code ScannerS–2 that performs parameter scans and checks parameter points in theories beyond the Standard Model (BSM) with extended scalar sectors. ScannerS incorporates theoretical and experimental constraints from many different sources in order to judge whether a parameter point is allowed or excluded at approximately 95%CL. The BSM models implemented in ScannerS include m
We introduce four-point functions in the hadronic ladder resummation approach to large N-c QCD Green functions. We determine the relevant one to calculate the B-K kaon parameter in the chiral limit. This four-point function contains both the large momenta QCD OPE and the small momenta ChPT at NLO limits, analytically. We get (B) over cap (X)(K) = 0.38 +/- 0.15. We also give the ChPT result at NLO
We calculated the vector, axial-vector, scalar and pseudo-scalar two-point functions up to two-loop level in the low-energy effective field theory for three different QCD-like theories. In addition we also calculated the pseudo-scalar decay constant G M. The QCD-like theories we used are those with fermions in a complex, real or pseudoreal representation with in general n flavours. These case corr
Diffractive excitation is usually described by the Good-Walker formalism for low masses, and by the triple-Regge formalism for high masses. In the Good-Walker formalism the cross section is determined by the fluctuations in the interaction. In this paper we show that by taking the fluctuations in the BFKL ladder into account, it is possible to describe both low and high mass excitation by the Good
