The Barometer

(Lt. Comdr. B.D. Cole, USN, comments on Lt. N. Clark Williams\u27 article, Decision Analysis: Toward Better Naval Management Decisions, July-August 1974.), (Lt. Comdr. Peter H. Cressy amplifies on his article, Developing an Alternative Approach to Race Relations Education: Identifying Military Middle Management Resistance, July-August 1974), and (Comdr. Warren H. Winchester, USN, comments on Lt. Comdr, Peter H. Cressy\u27s and Dr. Louis R. Desfosses\u27 article Developing an Alternative Approach to Race Relations Education, July-August 1974.

Jazz Choir presentation 'A Jazzy Diversion' for 2014 Teapot Valley Choral Summer Camp

I was contracted to devise and direct an experiential jazz choir workshop 'A Jazzy Diversion' for the 2014 Teapot Valley Choral Summer Camp, Nelson, NZ. utilising a body of arrangements from my personal library. Works included 'I'm Beginning To See The Light" (Ellington, D., George, D., Hodges, J., James, H.) 'Crazy Rhythm', 'No Moon At All. (Mann, D.), 'Crazy Rhythm' (Caesar,I., Meyer, J., Kahn, R.J. 'Cole Porter Latin Medley (Porter, C. arr Senior), 'The More I See You' (Warren, H.), 'When I Fall In Love' (Young, V., Heyman, E.), 'In A Mellow Tone' (Ellington, D., Gabler, M.

The Calcium Triplet metallicity calibration for galactic bulge stars

We present a new calibration of the Calcium II Triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and in general it is especially suited for solar and supersolar metallicity giants, typical of external massive galaxies. About 150 bulge K giants were observed with the GIRAFFE spectrograph at VLT, both at resolution R~20,000 and at R~6,000. In the first case, the spectra allowed us to perform direct determination of Fe abundances from several unblended Fe lines, deriving what we call here high resolution [Fe/H] measurements. The low resolution spectra allowed us to measure equivalent widths of the two strongest lines of the near infrared Calcium II triplet at 8542 and 8662 A. By comparing the two measurements we derived a relation between Calcium equivalent widths and [Fe/H] that is linear over the metallicity range probed here, -1<[Fe/H]<+0.7. By adding a small second order correction, based on literature globular cluster data, we derived the unique calibration equation [Fe/H]$_{CaT} = -3.150 + 0.432W' + 0.006W'^2$, with a rms dispersion of 0.197 dex, valid across the whole metallicity range -2.3<[Fe/H]<+0.7.Comment: Accepted for publication in A&

Metallicities and Radial Velocities of Five Open Clusters Including a New Candidate Member of the Monoceros Stream

Near infrared spectra of 133 red giant stars from ten Galactic open clusters and two Galactic globular clusters spanning 2.2 dex in metallicity and 11 Gyr in age are presented. We combine this sample with ten clusters from Cole and collaborators to investigate the Ca II triplet line strengths and their relation to cluster metallicity and position along the red giant branch. We show that characterizing the stellar surface gravity using Ks band photometry (relative to the horizontal branch) taken from the Two Micron All-Sky Survey allows for metallicity measurements at least as precise as those derived using V or I band data. This has the great advantage that uniform photometry and reliable astrometry is available for a large number of clusters. Using Ks band photometry also reduces the effect of differential reddening within a given cluster. We find no significant evidence for age or metallicity effects to the linear Ca II triplet - metallicity relationship over the small range in magnitudes studied when homogeneous reference metallicities are used. We derive the first spectroscopic metallicity and new radial velocity estimates for five open clusters: Berkeley 81, Berkeley 99, IC 1311, King 2, and NGC 7044. King 2 has an anomalous radial velocity compared with the local disk population. We discuss the possibility that it is part of the Monoceros tidal stream.Comment: 35 pages, 14 figures, 9 tables. Accepted for publication in MNRA

Radial Velocity and Metallicity of the Globular Cluster IC4499 Obtained with AAOmega

We present radial velocity and metallicity measurements for the far-southern Galactic globular cluster IC4499. We selected several hundred target red giant stars in and around the cluster from the 2MASS point source catalog, and obtained spectra at the near-infrared calcium triplet using the AAOmega spectrograph. Observations of giants in globular clusters M4, M22, and M68 were taken to provide radial velocity and metallicity comparison objects. Based on velocity data we conclude that 43 of our targets are cluster members, by far the largest sample of IC4499 giants spectroscopically studied. We determine the mean heliocentric radial velocity of the cluster to be 31.5 plus or minus 0.4 km/s, and find the most likely central velocity dispersion to be 2.5 plus or minus 0.5 km/s. This leads to a dynamical mass estimate for the cluster of 93 plus or minus 37 thousand solar masses. We are sensitive to cluster rotation down to an amplitude of about 1 km/s, but no evidence for cluster rotation is seen. The cluster metallicity is found to be [Fe/H] = -1.52 plus or minus 0.12 on the Carretta-Gratton scale. The radial velocity of the cluster, previously highly uncertain, is consistent with membership in the Monoceros tidal stream, but also with a halo origin. The horizontal branch morphology of the cluster is slightly redder than average for its metallicity, but it is likely not unusually young compared to other clusters of the halo. The new constraints on the cluster kinematics and metallicity may give insight into its extremely high specific frequency of RR Lyrae stars.Comment: Accepted to MNRAS, 13 pages, 9 figure

Simulating the Universe with MICE: The abundance of massive clusters

We introduce a new set of large N-body runs, the MICE simulations, that provide a unique combination of very large cosmological volumes with good mass resolution. They follow the gravitational evolution of ~ 8.5 billion particles (2048^3) in volumes covering up to 450 (Gpc/h)^3. Our main goal is to accurately model and calibrate basic cosmological probes that will be used by upcoming astronomical surveys. Here we take advantage of the very large volumes of MICE to make a robust sampling of the high-mass tail of the halo mass function (MF). We discuss and avoid possible systematic effects in our study, and do a detailed analysis of different error estimators. We find that available fits to the local abundance of halos (Warren et al. (2006)) match well the abundance in MICE up to M ~ 10^{14}\Msun, but significantly deviate for larger masses, underestimating the mass function by 10% (30%) at M = 3.16 x 10^{14}\Msun (10^{15}\Msun). Similarly, the widely used Sheth & Tormen (1999) fit, if extrapolated to high redshift assuming universality, leads to an underestimation of the cluster abundance by 30%, 20% and 15% at z=0, 0.5, 1 for M ~ [7 - 2.5 - 0.8] x 10^{14}\Msun respectively ($\nu = \delta_c/\sigma ~ 3$). We provide a re-calibration of the halo MF valid over 5 orders of magnitude in mass, 10^{10} < M/(\Msun) < 10^{15}, that accurately describes its redshift evolution up to z=1. We explore the impact of this re-calibration on the determination of dark-energy, and conclude that using available fits may systematically bias the estimate of w by as much as 50% for medium-depth (z <= 1) surveys. MICE halo catalogues are publicly available at http://www.ice.cat/miceComment: 16 pages, 11 figures. Data publicly available at http://www.ice.cat/mice. New version adds discussion on halo definition (SO vs FoF) and minor modifications. Accepted for publication in MNRA

The halo mass function through the cosmic ages

In this paper we investigate how the halo mass function evolves with redshift, based on a suite of very large (with N_p = 3072^3 - 6000^3 particles) cosmological N-body simulations. Our halo catalogue data spans a redshift range of z = 0-30, allowing us to probe the mass function from the dark ages to the present. We utilise both the Friends-of-Friends (FOF) and Spherical Overdensity (SO) halofinding methods to directly compare the mass function derived using these commonly used halo definitions. The mass function from SO haloes exhibits a clear evolution with redshift, especially during the recent era of dark energy dominance (z < 1). We provide a redshift-parameterised fit for the SO mass function valid for the entire redshift range to within ~20% as well as a scheme to calculate the mass function for haloes with arbitrary overdensities. The FOF mass function displays a weaker evolution with redshift. We provide a `universal' fit for the FOF mass function, fitted to data across the entire redshift range simultaneously, and observe redshift evolution in our data versus this fit. The relative evolution of the mass functions derived via the two methods is compared and we find that the mass functions most closely match at z=0. The disparity at z=0 between the FOF and SO mass functions resides in their high mass tails where the collapsed fraction of mass in SO haloes is ~80% of that in FOF haloes. This difference grows with redshift so that, by z>20, the SO algorithm finds a ~50-80% lower collapsed fraction in high mass haloes than does the FOF algorithm, due in part to the significant over-linking effects known to affect the FOF method.Comment: v4, 16 pages, 16 colour figures. Changed to match MNRAS print version. NOTE: v1 of this paper has a typo in the fitting function. Please ensure you use the latest versio