15,315 research outputs found
The Language of Bias: A Linguistic Approach to Understanding Intergroup Relations
[Excerpt] This chapter explores the role of language in the relationship between diversity and team performance. Specifically, we consider how a linguistic approach to social categorization may be used to study the social psychological mechanisms that underlie diversity effects. Using the results of a study examining the effects of gender, ethnicity and tenure on language abstraction, we consider the potential implications for team processes and effectiveness. In addition, we propose a revised team input-process-output model that highlights the potential effects of language on team processes. We conclude by suggesting directions for future research linking diversity, linguistic categorization and team effectiveness
Detection of the 13CO(J=6-5) Transition in the Starburst Galaxy NGC 253
We report the detection of 13CO(J=6-5) emission from the nucleus of the
starburst galaxy NGC 253 with the redshift (z) and Early Universe Spectrometer
(ZEUS), a new submillimeter grating spectrometer. This is the first
extragalactic detection of the 13CO(J=6-5) transition, which traces warm, dense
molecular gas. We employ a multi-line LVG analysis and find ~ 35% - 60% of the
molecular ISM is both warm (T ~ 110 K) and dense (n(H2) ~ 10^4 cm^-3). We
analyze the potential heat sources, and conclude that UV and X-ray photons are
unlikely to be energetically important. Instead, the molecular gas is most
likely heated by an elevated density of cosmic rays or by the decay of
supersonic turbulence through shocks. If the cosmic rays and turbulence are
created by stellar feedback within the starburst, then our analysis suggests
the starburst may be self-limiting.Comment: 4 pages, 2 figures, accepted by ApJ Letter
A quasioptical steering system for the CCAT/XSPEC submillimeter multi-object spectrometer
A two arm, opto-mechanical positioner mechanism is presented in this proceedings as a candidate steering system for the millimeter-wave XSPEC spectrograph. The design is well matched to the expected target density on the sky, and meeting all requirements of the Cerro Chajnantor Atacama Telescope (CCAT), site environmental conditions (e.g., operating temperature and power dissipation), and the positioning requirements themselves for acquiring and tracking astronomical objects whose light is fed into the XSPEC spectrograph units. The prototype design has been fabricated and tested for basic operations
Mid-J CO Emission From NGC 891: Microturbulent Molecular Shocks in Normal Star Forming Galaxies
We have detected the CO(6-5), CO(7-6), and [CI] 370 micron lines from the
nuclear region of NGC 891 with our submillimeter grating spectrometer ZEUS on
the CSO. These lines provide constraints on photodissociation region (PDR) and
shock models that have been invoked to explain the H_2 S(0), S(1), and S(2)
lines observed with Spitzer. We analyze our data together with the H_2 lines,
CO(3-2), and IR continuum from the literature using a combined PDR/shock model.
We find that the mid-J CO originates almost entirely from shock-excited warm
molecular gas; contributions from PDRs are negligible. Also, almost all the H_2
S(2) and half of the S(1) line is predicted to emerge from shocks. Shocks with
a pre-shock density of 2x10^4 cm^-3 and velocities of 10 km/s and 20 km/s for
C-shocks and J-shocks, respectively, provide the best fit. In contrast, the
[CI] line emission arises exclusively from the PDR component, which is best
parameterized by a density of 3.2x10^3 cm^-3 and a FUV field of G_o = 100 for
both PDR/shock-type combinations. Our mid-J CO observations show that
turbulence is a very important heating source in molecular clouds, even in
normal quiescent galaxies. The most likely energy sources for the shocks are
supernovae or outflows from YSOs. The energetics of these shock sources favor
C-shock excitation of the lines.Comment: 18 pages, 2 figures, 6 tables, accepted by Ap
Development of Aluminum LEKIDs for Balloon-Borne Far-IR Spectroscopy
We are developing lumped-element kinetic inductance detectors (LEKIDs)
designed to achieve background-limited sensitivity for far-infrared (FIR)
spectroscopy on a stratospheric balloon. The Spectroscopic Terahertz Airborne
Receiver for Far-InfraRed Exploration (STARFIRE) will study the evolution of
dusty galaxies with observations of the [CII] 158 m and other atomic
fine-structure transitions at , both through direct observations of
individual luminous infrared galaxies, and in blind surveys using the technique
of line intensity mapping. The spectrometer will require large format
(1800 detectors) arrays of dual-polarization sensitive detectors with
NEPs of W Hz. The low-volume LEKIDs are fabricated
with a single layer of aluminum (20 nm thick) deposited on a crystalline
silicon wafer, with resonance frequencies of MHz. The inductor is a
single meander with a linewidth of 0.4 m, patterned in a grid to absorb
optical power in both polarizations. The meander is coupled to a circular
waveguide, fed by a conical feedhorn. Initial testing of a small array
prototype has demonstrated good yield, and a median NEP of
W Hz.Comment: accepted for publication in Journal of Low Temperature Physic
Individual Feed Intake of Transition Cows and Their Daily Activity Measures of Temperature, Eating, Rumination, Resting, and Activity Times
Fifteen transition dairy cows bearing CowSensorÂź ear tags were monitored during 14 days before and after calving to assess temperature and behavior outcomes recorded by the sensors, in addition to actual individual dry matter and as-fed feed intake. The sensorsâcompared with reported visual observation studiesâunderestimated eating and resting times, but rumination time was estimated reasonably accurately. Expected changes in rumination (decreased acutely before calving and increased linearly to day 14) and general activity (increased acutely just before calving) were observed. More studies are warranted to determine how to use these activity monitors in detecting health disorders of cows that affect milk yield
The Intracluster Medium in z > 1 Galaxy Clusters
The Chandra X-ray Observatory was used to obtain a 190 ks image of three high
redshift galaxy clusters in one observation. The results of our analysis of
these data are reported for the two z > 1 clusters in this Lynx field,
including the most distant known X-ray selected cluster. Spatially-extended
X-ray emission was detected from both these clusters, indicating the presence
of hot gas in their intracluster media. A fit to the X-ray spectrum of RX
J0849+4452, at z=1.26, yields a temperature of kT = 5.8^{+2.8}_{-1.7} keV.
Using this temperature and the assumption of an isothermal sphere, the total
mass of RX J0849+4452 is found to be 4.0^{+2.4}_{-1.9} X 10^{14} h_{65}^{-1}
M_{\sun} within r = 1 h_{65}^{-1} Mpc. The T_x for RX J0849+4452 approximately
agrees with the expectation based on its L_{bol} = 3.3^{+0.9}_{-0.5} X 10^{44}^{-1} according to the low redshift L_x - T_x relation. The very
different distributions of X-ray emitting gas and of the red member galaxies in
the two z > 1 clusters, in contrast to the similarity of the optical/IR colors
of those galaxies, suggests that the early-type galaxies mostly formed before
their host clusters.Comment: 4 pages in emulateapj style plus 2 color jpegs for Figure 3. Accepted
by The Astrophysical Journa
Abundances in Stars from the Red Giant Branch Tip to the Near the Main Sequence in M71: I. Sample Selection, Observing Strategy and Stellar Parameters
We present the sample for an abundance analysis of 25 members of M71 with
luminosities ranging from the red giant branch tip to the upper main sequence.
The spectra are of high dispersion and of high precision. We describe the
observing strategy and determine the stellar parameters for the sample stars
using both broad band colors and fits of H profiles. The derived
stellar parameters agree with those from the Yale stellar evolutionary
tracks to within 50 -- 100K for a fixed log g, which is within the level of the
uncertainties.Comment: Minor changes to conform to version accepted for publication, with
several new figures (Paper 1 of a pair
Formation of the oxygen torus in the inner magnetosphere: Van Allen Probes observations
We study the formation process of an oxygen torus during the 12â15 November 2012 magnetic storm, using the magnetic field and plasma wave data obtained by Van Allen Probes. We estimate the local plasma mass density (ÏL) and the local electron number density (neL) from the resonant frequencies of standing AlfvĂ©n waves and the upper hybrid resonance band. The average ion mass (M) can be calculated by M ⌠ÏL/neL under the assumption of quasi-neutrality of plasma. During the storm recovery phase, both Probe A and Probe B observe the oxygen torus at L = 3.0â4.0 and L = 3.7â4.5, respectively, on the morning side. The oxygen torus has M = 4.5â8 amu and extends around the plasmapause that is identified at LâŒ3.2â3.9. We find that during the initial phase, M is 4â7 amu throughout the plasma trough and remains at âŒ1 amu in the plasmasphere, implying that ionospheric O+ ions are supplied into the inner magnetosphere already in the initial phase of the magnetic storm. Numerical calculation under a decrease of the convection electric field reveals that some of thermal O+ ions distributed throughout the plasma trough are trapped within the expanded plasmasphere, whereas some of them drift around the plasmapause on the dawnside. This creates the oxygen torus spreading near the plasmapause, which is consistent with the Van Allen Probes observations. We conclude that the oxygen torus identified in this study favors the formation scenario of supplying O+ in the inner magnetosphere during the initial phase and subsequent drift during the recovery phase
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