The X-ray Size-Temperature Relation for Intermediate Redshift Galaxy Clusters

We present the first measurements of the X-ray size-temperature (ST) relation in intermediate redshift (z~0.30) galaxy clusters. We interpret the local ST relation (z~0.06) in terms of underlying scaling relations in the cluster dark matter properties, and then we use standard models for the redshift evolution of those dark matter properties to show that the ST relation does not evolve with redshift. We then use ROSAT HRI observations of 11 clusters to examine the intermediate redshift ST relation; for currently favored cosmological parameters, the intermediate redshift ST relation is consistent with that of local clusters. Finally, we use the ST relation and our evolution model to measure angular diameter distances; with these 11 distances we evaluate constraints on Omega_M and Omega_L which are consistent with those derived from studies of Type Ia supernovae. The data rule out a model with Omega_M=1 and Omega_L=0 with 2.5 sigma confidence. When limited to models where Omega_M+Omega_L=1, these data are inconsistent with Omega_M=1 with 3 sigma confidence.Comment: ApJ: submitted April 7, accepted June 28, to appear Dec 1 (vol 544

Lamb Shift of 3P and 4P states and the determination of α\alpha

The fine structure interval of P states in hydrogenlike systems can be determined theoretically with high precision, because the energy levels of P states are only slightly influenced by the structure of the nucleus. Therefore a measurement of the fine structure may serve as an excellent test of QED in bound systems or alternatively as a means of determining the fine structure constant $\alpha$ with very high precision. In this paper an improved analytic calculation of higher-order binding corrections to the one-loop self energy of 3P and 4P states in hydrogen-like systems with low nuclear charge number $Z$ is presented. A comparison of the analytic results to the extrapolated numerical data for high $Z$ ions serves as an independent test of the analytic evaluation. New theoretical values for the Lamb shift of the P states and for the fine structure splittings are given.Comment: 33 pages, LaTeX, 4 tables, 4 figure

QED self-energy contribution to highly-excited atomic states

We present numerical values for the self-energy shifts predicted by QED (Quantum Electrodynamics) for hydrogenlike ions (nuclear charge $60 \le Z \le 110$) with an electron in an $n=3$, 4 or 5 level with high angular momentum ($5/2\le j \le 9/2$). Applications include predictions of precision transition energies and studies of the outer-shell structure of atoms and ions.Comment: 20 pages, 5 figure

Deconvolution of complex G protein-coupled receptor signaling in live cells using dynamic mass redistribution measurements

Label-free biosensor technology based on dynamic mass redistribution (DMR) of cellular constituents promises to translate GPCR signaling into complex optical 'fingerprints' in real time in living cells. Here we present a strategy to map cellular mechanisms that define label-free responses, and we compare DMR technology with traditional second-messenger assays that are currently the state of the art in GPCR drug discovery. The holistic nature of DMR measurements enabled us to (i) probe GPCR functionality along all four G-protein signaling pathways, something presently beyond reach of most other assay platforms; (ii) dissect complex GPCR signaling patterns even in primary human cells with unprecedented accuracy; (iii) define heterotrimeric G proteins as triggers for the complex optical fingerprints; and (iv) disclose previously undetected features of GPCR behavior. Our results suggest that DMR technology will have a substantial impact on systems biology and systems pharmacology as well as for the discovery of drugs with novel mechanisms

Higher-order binding corrections to the Lamb shift of 2P states

We present an improved calculation of higher-order corrections to the one-loop self energy of 2P states in hydrogen-like systems with small nuclear charge Z. The method is based on a division of the integration with respect to the photon energy into a high- and a low-energy part. The high-energy part is calculated by an expansion of the electron propagator in powers of the Coulomb field. The low-energy part is simplified by the application of a Foldy-Wouthuysen transformation. This transformation leads to a clear separation of the leading contribution from the relativistic corrections and removes higher order terms. The method is applied to the 2P_{1/2} and 2P_{3/2} states in atomic hydrogen. The results lead to new theoretical values for the Lamb shifts and the fine structure splitting.Comment: 18 pages, LaTeX. In comparison to the journal version, it contains an added note (2000) which reflects the current status of Lamb shift calculation

Outer Regions of the Cluster Gaseous Atmospheres

We present a systematic study of the hot gas distribution in the outer regions of regular clusters using ROSAT PSPC data. Outside the cooling flow region, the beta-model describes the observed surface brightness closely, but not precisely. Between 0.3 and 1 virial radii, the profiles are characterized by a power law with slope, expressed in terms of the beta parameter, in the range beta=0.65 to 0.85. The values of beta in this range of radii are typically larger by ~0.05 than those derived from the global fit. There is a mild trend for the slope to increase with temperature, from ~0.68 for 3 keV clusters to ~0.8 for 10 keV clusters; however, even at high temperatures there are clusters with flat gas profiles, 0.7. Our values of beta at large radius are systematically higher, and the trend of beta with temperature is weaker than was previously found; the most likely explanation is that earlier studies were affected by an incomplete exclusion of the central cooling flow regions. For our regular clusters, the gas distribution at large radii is quite close to spherically symmetric and this is shown not to be an artifact of the sample selection. The gas density profiles are very similar when compared in the units of cluster virial radius. The radius of fixed mean gas overdensity 1000 (corresponding to the dark matter overdensity 200 for Omega=0.2) shows a tight correlation with temperature, R~T**0.5, as expected from the virial theorem for clusters with the universal gas fraction. At a given temperature, the rms scatter of the gas overdensity radius is only ~7% which translates into a 20% scatter of the gas mass fraction, including statistical scatter due to measurement uncertainties.Comment: ApJ in press, submitted 11/30/9

Calculation of the Electron Self Energy for Low Nuclear Charge

We present a nonperturbative numerical evaluation of the one-photon electron self energy for hydrogenlike ions with low nuclear charge numbers Z=1 to 5. Our calculation for the 1S state has a numerical uncertainty of 0.8 Hz for hydrogen and 13 Hz for singly-ionized helium. Resummation and convergence acceleration techniques that reduce the computer time by about three orders of magnitude were employed in the calculation. The numerical results are compared to results based on known terms in the expansion of the self energy in powers of (Z alpha).Comment: 10 pages, RevTeX, 2 figure

Electron Self Energy for the K and L Shell at Low Nuclear Charge

A nonperturbative numerical evaluation of the one-photon electron self energy for the K- and L-shell states of hydrogenlike ions with nuclear charge numbers Z=1 to 5 is described. Our calculation for the 1S state has a numerical uncertainty of 0.8 Hz in atomic hydrogen, and for the L-shell states (2S and 2P) the numerical uncertainty is 1.0 Hz. The method of evaluation for the ground state and for the excited states is described in detail. The numerical results are compared to results based on known terms in the expansion of the self energy in powers of (Z alpha).Comment: 21 pages, RevTeX, 5 Tables, 6 figure

Relativistic and Radiative Energy Shifts for Rydberg States

We investigate relativistic and quantum electrodynamic effects for highly-excited bound states in hydrogenlike systems (Rydberg states). In particular, hydrogenic one-loop Bethe logarithms are calculated for all circular states (l = n-1) in the range 20 <= n <= 60 and successfully compared to an existing asymptotic expansion for large principal quantum number n. We provide accurate expansions of the Bethe logarithm for large values of n, for S, P and circular Rydberg states. These three expansions are expected to give any Bethe logarithms for principal quantum number n > 20 to an accuracy of five to seven decimal digits, within the specified manifolds of atomic states. Within the numerical accuracy, the results constitute unified, general formulas for quantum electrodynamic corrections whose validity is not restricted to a single atomic state. The results are relevant for accurate predictions of radiative shifts of Rydberg states and for the description of the recently investigated laser-dressed Lamb shift, which is observable in a strong coherent-wave light field.Comment: 8 pages; RevTeX

Collective Excitations of (154)Sm nucleus at FEL{gamma}+LHC Collider

The production of collective excitations of the (154)Sm at FEL{gamma}+LHC collider is investigated. We show that this machine will be a powerful tool for investigation of high energy level excitations.Comment: 6 pages, 1 figure, 4 table