Motion systems providing three or four degrees of freedom

A motion system is provided by a platform generally parallel to a base and connected thereto by a column and powered and controlled extensible members, at least three of which are connected between distributed points around the column. In a three degree of freedom device, the column is conical, rigidly supported at its base with a universal joint at its top. The points of attachment define triangles in the base and in the platform surrounding the column with one extensible member connected between each. In the four degree of freedom version, the column is modified by making it effectively a column which is pivoted or guided at the base or contains an extensible member, preferably retains its triangular shape and its universal joint connection to the platform at its apex. For stability four powered and controlled extensible members are provided between points in the base and platform distributed around the column, a preferred pattern of arrangement being a square with the column at the center

The Space Density Evolution of Wet and Dry Mergers in the Canada-France-Hawaii Telescope Legacy Survey

We analyze 1298 merging galaxies with redshifts up to z = 0.7 from the Canada-France-Hawaii Telescope Legacy Survey, taken from the catalog presented in Bridge et al. (2010). By analyzing the internal colors of these systems, we show that so-called wet and dry mergers evolve in different senses, and quantify the space densities of these systems. The local space density of wet mergers is essentially identical to the local space density of dry mergers. The evolution in the total merger rate is modest out to z ∼ 0.7, although the wet and dry populations have different evolutionary trends. At higher redshifts dry mergers make a smaller contribution to the total merging galaxy population, but this is offset by a roughly equivalent increase in the contribution from wet mergers. By comparing the mass density function of early-type galaxies to the corresponding mass density function for merging systems, we show that not all the major mergers with the highest masses (M_(stellar) > 10^(11)M☉) will end up with the most massive early-type galaxies, unless the merging timescale is dramatically longer than that usually assumed. On the other hand, the usually-assumed merging timescale of ∼ 0.5–1 Gyr is quite consistent with the data if we suppose that only less massive early-type galaxies form via mergers. Since low-intermediate mass ellipticals are 10–100 times more common than their most massive counterparts, the hierarchical explanation for the origin of early-type galaxies may be correct for the vast majority of early-types, even if incorrect for the most massive ones

A Close-pair Analysis of Damp Mergers at Intermediate Redshifts

We have studied the kinematics of ~2800 candidate close-pair galaxies at 0.1 < z < 1.2 identified from the Canada-France-Hawaii Telescope Legacy Survey fields. Spectra of these systems were obtained using spectrometers on the 6.5 m Magellan and 5 m Hale telescopes. These data allow us to constrain the rate of dry mergers at intermediate redshifts and to test the "hot halo" model for quenching of star formation. Using virial radii estimated from the correlation between dynamical and stellar masses published by Leauthaud et al., we find that around 1/5 of our candidate pairs are likely to share a common dark matter halo (our metric for close physical association). These pairs are divided into red-red, blue-red, and blue-blue systems using the rest-frame colors classification method introduced in Chou et al.. Galaxies classified as red in our sample have very low star formation rates, but they need not be totally quiescent, and hence we refer to them as "damp," rather than "dry," systems. After correcting for known selection effects, the fraction of blue-blue pairs is significantly greater than that of red-red and blue-red pairs. Red-red pairs are almost entirely absent from our sample, suggesting that damp mergers are rare at z ~ 0.5. Our data support models with a short merging timescale (<0.5 Gyr) in which star formation is enhanced in the early phase of mergers, but quenched in the late phase. Hot halo models may explain this behavior, but only if virial shocks that heat gas are inefficient until major mergers are nearly complete

The Space Density Evolution of Wet and Dry Mergers in the Canada-France-Hawaii Telescope Legacy Survey

We analyze 1298 merging galaxies with redshifts up to z=0.7 from the Canada-France-Hawaii Telescope Legacy Survey, taken from the catalog presented in Bridge et al. (2010). By analyzing the internal colors of these systems, we show that so-called wet and dry mergers evolve in different senses, and quantify the space densities of these systems. The local space density of wet mergers is essentially dentical to the local space density of dry mergers. The evolution in the total merger rate is modest out to z ~ 0.7, although the wet and dry populations have different evolutionary trends. At higher redshifts dry mergers make a smaller contribution to the total merging galaxy population, but this is offset by a roughly equivalent increase in the contribution from wet mergers. By comparing the mass density function of early-type galaxies to the corresponding mass density function for merging systems, we show that not all the major mergers with the highest masses (M_stellar > 10^11 M_solar) will end up with the most massive early-type galaxies, unless the merging timescale is dramatically longer than that usually assumed. On the other hand, the usually-assumed merging timescale of ~ 0.5-1 Gyr is quite consistent with the data if we suppose that only less massive early-type galaxies form via mergers. Since low-intermediate mass ellipticals are 10 --100 times more common than their most massive counterparts, the hierarchical explanation for the origin of early-type galaxies may be correct for the vast majority of early-types, even if incorrect for the most massive ones.Comment: 10 pages, 8 figures. Accepted by A

Ehlers-Danlos Syndrome Hypermobility Type is Associated with Rheumatic Diseases

We retrospectively analyzed electronic medical records of patients with Ehlers-Danlos Syndrome hypermobility type (HEDS), including demographic information, workup, rheumatological diagnoses in order to determine its association with rheumatological conditions. HEDS Patients were stratified according to level of workup received (no additional work (physical exam only) = NWU, limited workup = LWU, comprehensive workup = CWU)). HEDS patients were predominantly female (21:4, F:M). The percentage of patients with at least one rheumatological condition was significantly correlated with level of workup (NWU, 9.2%; LWU, 33.3%, CWU, 67.1%; p-value \u3c 0.0001). The HLA-B27 antigen was more prevalent (p-value \u3c 2.2 × 10 –8 ) in the CWU HEDS patients (23.9%) than in the general population of the United States (6.1%). HEDS with CWU were associated with more rheumatological conditions (i.e. psoriasis, ankylosing spondylitis, rheumatoid arthritis, fibromyalgia) than those with NWU or LWU. In conclusion, HEDS is associated with complicated rheumatological conditions, which are uncovered by comprehensive workup. These conditions require different clinical management strategies than HEDS, and left untreated could contribute to the pain or even physical disability (i.e. joint erosions) in HEDS patients. While the mechanisms underlying these associations are unknown, it is important that all HEDS patients receive adequate workup to ensure a complete clinical understanding for the best care strategy possible

Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. PFS will cover a 1.3 degree diameter field with 2394 fibers to complement the imaging capabilities of Hyper SuprimeCam. To retain high throughput, the final positioning accuracy between the fibers and observing targets of PFS is required to be less than 10um. The metrology camera system (MCS) serves as the optical encoder of the fiber motors for the configuring of fibers. MCS provides the fiber positions within a 5um error over the 45 cm focal plane. The information from MCS will be fed into the fiber positioner control system for the closed loop control. MCS will be located at the Cassegrain focus of Subaru telescope in order to to cover the whole focal plane with one 50M pixel Canon CMOS camera. It is a 380mm Schmidt type telescope which generates a uniform spot size with a 10 micron FWHM across the field for reasonable sampling of PSF. Carbon fiber tubes are used to provide a stable structure over the operating conditions without focus adjustments. The CMOS sensor can be read in 0.8s to reduce the overhead for the fiber configuration. The positions of all fibers can be obtained within 0.5s after the readout of the frame. This enables the overall fiber configuration to be less than 2 minutes. MCS will be installed inside a standard Subaru Cassgrain Box. All components that generate heat are located inside a glycol cooled cabinet to reduce the possible image motion due to heat. The optics and camera for MCS have been delivered and tested. The mechanical parts and supporting structure are ready as of spring 2016. The integration of MCS will start in the summer of 2016.Comment: 11 pages, 15 figures. SPIE proceeding. arXiv admin note: text overlap with arXiv:1408.287

The Circumnuclear Molecular Gas in the Seyfert Galaxy NGC4945

We have mapped the central region of NGC 4945 in the $J=2\to1$ transition of $^{12}$CO, $^{13}$CO, and C$^{18}$O, as well as the continuum at 1.3 mm, at an angular resolution of 5\farc \times 3\farc with the Submillimeter Array. The relative proximity of NGC 4945 (distance of only 3.8 Mpc) permits a detailed study of the circumnuclear molecular gas and dust in a galaxy exhibiting both an AGN (classified as a Seyfert 2) and a circumnuclear starburst in an inclined ring with radius $\sim$2\farcs5 ($\sim$50 pc). We find that all three molecular lines trace an inclined rotating disk with major axis aligned with that of the starburst ring and large-scale galactic disk, and which exhibits solid-body rotation within a radius of $\sim$5\farc ($\sim$95 pc). We infer an inclination for the nuclear disk of $62^{\circ} \pm 2^{\circ}$, somewhat smaller than the inclination of the large-scale galactic disk of $\sim$$78^{\circ}$. The continuum emission at 1.3 mm also extends beyond the starburst ring, and is dominated by thermal emission from dust. If it traces the same dust emitting in the far-infrared, then the bulk of this dust must be heated by star-formation activity rather than the AGN. We discover a kinematically-decoupled component at the center of the disk with a radius smaller than 1\farcs4 (27 pc), but which spans approximately the same range of velocities as the surrounding disk. This component has a higher density than its surroundings, and is a promising candidate for the circumnuclear molecular torus invoked by AGN unification models.Comment: 13 pages, 10 figures,accepted by Ap