Central galaxy growth and feedback in the most massive nearby cool core cluster

We present multi-wavelength observations of the centre of RXCJ1504.1-0248 - the galaxy cluster with the most luminous and relatively nearby cool core at z~0.2. Although there are several galaxies within 100 kpc of the cluster core, only the brightest cluster galaxy (BCG), which lies at the peak of the X-ray emission, has blue colours and strong line-emission. Approximately 80 Msun/yr of intracluster gas is cooling below X-ray emitting temperatures, similar to the observed UV star formation rate of ~140 Msun/yr. Most star formation occurs in the core of the BCG and in a 42 kpc long filament of blue continuum, line emission, and X-ray emission, that extends southwest of the galaxy. The surrounding filamentary nebula is the most luminous around any observed BCG. The number of ionizing stars in the BCG is barely sufficient to ionize and heat the nebula, and the line ratios indicate an additional heat source is needed. This heat source can contribute to the H\alpha-deduced star formation rates (SFRs) in BCGs and therefore the derived SFRs should only be considered upper limits. AGN feedback can slow down the cooling flow to the observed mass deposition rate if the black hole accretion rate is of the order of 0.5 Msun/yr at 10% energy output efficiency. The average turbulent velocity of the nebula is vturb ~325 km/s which, if shared by the hot gas, limits the ratio of turbulent to thermal energy of the intracluster medium to less than 6%.Comment: 15 pages, 11 figures, MNRAS in press. Corrected typo in abstract

New Approach to Nonlinear Dynamics of Fullerenes and Fullerites

New type of nonlinear (anharmonic) excitations -- bushes of vibrational modes -- in physical systems with point or space symmetry are discussed. All infrared active and Raman active bushes for C60 fulerene are found by means of special group-theoretical methods.Comment: LaTeX, 8 pages, to be published in Fizika Tverdogo Tela, 200

Magnetohydrodynamics (MHD) Engineering Test Facility (ETF) 200 MWe power plant. Design Requirements Document (DRD)

A description and the design requirements for the 200 MWe (nominal) net output MHD Engineering Test Facility (ETF) Conceptual Design, are presented. Performance requirements for the plant are identified and process conditions are indicated at interface stations between the major systems comprising the plant. Also included are the description, functions, interfaces and requirements for each of these major systems. The lastest information (1980-1981) from the MHD technology program are integrated with elements of a conventional steam electric power generating plant

Enhanced heterogeneity of rpoB in Mycobacterium tuberculosis found at low pH.

OBJECTIVES: The aim of this study was to gain an insight into the molecular mechanisms of the evolution of rifampicin resistance in response to controlled changes in the environment. METHODS: We determined the proportion of rpoB mutants in the chemostat culture and characterized the sequence of mutations found in the rifampicin resistance-determining region of rpoB in a steady-state chemostat at pH 7.0 and 6.2. RESULTS: The overall proportion of rpoB mutants of strain H37Rv remained constant for 37 days at pH 7.0, ranging between 3.6 x 10(-8) and 8.9 x 10(-8); however, the spectrum of mutations varied. The most commonly detected mutation, serine to leucine mutation at codon 531 (S531L), increased from 40% to 89%, while other mutations (S531W, H526Y, H526D, H526R, S522L and D516V) decreased over the 37 day sampling period. Changing the pH from 7.0 to 6.2 did not significantly alter the overall proportion of mutants, but resulted in a decrease in the percentage of strains harbouring S531L (from 89% to 50%) accompanied by an increase in the range of different mutations from 4 to 12. CONCLUSIONS: The data confirm that the fitness of strains with the S531L mutation is greater than that of strains containing other mutations. We also conclude that at low pH the environment is permissive for a wider spectrum of mutations, which may provide opportunities for a successful mutant to survive

Measurements of Isoprene-Derived Organosulfates in Ambient Aerosols by Aerosol Time-of-Flight Mass Spectrometry - Part 1: Single Particle Atmospheric Observations in Atlanta

Organosulfate species have recently been identified as a potentially significant class of secondary organic aerosol (SOA) species, yet little is known about their behavior in the atmosphere. In this work, organosulfates were observed in individual ambient aerosols using single particle mass spectrometry in Atlanta, GA during the 2002 Aerosol Nucleation and Characterization Experiment (ANARChE) and the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS). Organosulfates derived from biogenically produced isoprene were detected as deprotonated molecular ions in negative-ion spectra measured by aerosol time-of-flight mass spectrometry; comparison to high-resolution mass spectrometry data obtained from filter samples corroborated the peak assignments. The size-resolved chemical composition measurements revealed that organosulfate species were mostly detected in submicrometer aerosols and across a range of aerosols from different sources, consistent with secondary reaction products. Detection of organosulfates in a large fraction of negative-ion ambient spectra − ca. 90−95% during ANARChE and ~65% of submicrometer particles in AMIGAS − highlights the ubiquity of organosulfate species in the ambient aerosols of biogenically influenced urban environments

A SINFONI view of flies in the Spiderweb: a galaxy cluster in the making

The environment of the high-z radio galaxy PKS 1138-262 at z~2.2 is a prime example of a forming galaxy cluster. We use deep SINFONI data to perform a detailed study of the kinematics of the galaxies within 60 kpc of the radio core and we link this to the kinematics of the protocluster on the megaparsec scale. Identification of optical emission lines shows that 11 galaxies are at the redshift of the protocluster. The density of line emitters is more than an order of magnitude higher in the core of the protocluster than the larger scale environment. This implies a matter overdensity in the core of delta_m~70 which is similar to the outskirts of local galaxy clusters. The velocity distribution of the confirmed satellite galaxies shows a broad, double-peaked velocity structure with sigma=1360+/-206 km/s. A similar broad, double-peaked distribution was found in a previous study targeting the large scale protocluster structure, indicating that a common process is acting on both small and large scales. Including all spectroscopically confirmed protocluster galaxies, a velocity dispersion of 1013+/-87 km/s is found. We show that the protocluster has likely decoupled from the Hubble flow and is a dynamically evolved structure. Comparison to the Millenium simulation indicates that the protocluster velocity distribution is consistent with that of the most massive haloes at z~2, but we rule out that the protocluster is a fully virialized structure based on dynamical arguments and its X-ray luminosity. Comparison to merging haloes in the Millennium simulation shows that the structure as observed in and around the Spiderweb galaxy is best interpreted as being the result of a merger between two massive haloes. We propose that this merger can result in an increase in star formation and AGN activity in the protocluster core and is possibly an important stage in the evolution of massive cD galaxies.Comment: 12 pages, 7 figures. Accepted for publication in MNRA