1,008 research outputs found
One thousand good things in Nature: aspects of nearby Nature associated with improved connection to Nature
As our interactions with nature occur increasingly within urban landscapes, there is a need to consider how ‘mundane nature’ can be valued as a route for people to connect to nature. The content of a three good things in nature intervention, written by 65 participants each day for five days is analysed. Content analysis produced themes related to sensations, temporal change, active wildlife, beauty, weather, colour, good feelings and specific aspects of nature. The themes describe the everyday good things in nature, providing direction for those seeking to frame engaging conservation messages, plan urban spaces and connect people with nearby nature
Satisfiers and dissatisfiers for international vocational education students: A case study using narrative frames
While the satisfaction of international students is frequently surveyed, much of this research is based on a very limited range of closed-item data collection methods, producing findings that partially reflect the researchers’ assumptions in designing the survey items. Recognizing the potential value in using methods that are more open-ended and qualitative analyses, the present study employed narrative frames and follow-up interviews to explore the satisfiers and dissatisfiers for international vocational education students at one institution in New Zealand. Reporting on perceptions of the class, institution, and community, the findings identify the participants’ top-of-mind (dis)satisfiers and complement the existing literature by identifying seldom-reported themes. Discussion of issues in analyzing narrative frames is also provided
Deep Chandra Observations of the Compact Starburst Galaxy Henize 2-10: X-rays from the Massive Black Hole
We present follow-up X-ray observations of the candidate massive black hole
(BH) in the nucleus of the low-mass, compact starburst galaxy Henize 2-10.
Using new high-resolution observations from the Chandra X-ray Observatory
totaling 200 ks in duration, as well as archival Chandra observations from
2001, we demonstrate the presence of a previously unidentified X-ray point
source that is spatially coincident with the known nuclear radio source in
Henize 2-10 (i.e., the massive BH). We show that the hard X-ray emission
previously identified in the 2001 observation is dominated by a source that is
distinct from the nucleus, with the properties expected for a high-mass X-ray
binary. The X-ray luminosity of the nuclear source suggests the massive BH is
radiating significantly below its Eddington limit (~10^-6 L_Edd), and the soft
spectrum resembles other weakly accreting massive BHs including Sagittarius A*.
Analysis of the X-ray light curve of the nucleus reveals the tentative
detection of a ~9-hour periodicity, although additional observations are
required to confirm this result. Our study highlights the need for sensitive
high-resolution X-ray observations to probe low-level accretion, which is the
dominant mode of BH activity throughout the Universe.Comment: Accepted for publication in ApJ Letters. 7 pages, 4 figure
Facilitando la localización de videojuegos de rol masivos
In order to achieve total immersion in the game world, increasing therefore player’ satisfaction, localization should ideally aim at creating complete suspension of disbelief. However, time constraints and constant design and script changes mean that localisation is sometimes forced to trade quality in favor of speed, because missing release dates can mean multimillion losses. This article explains the strategies BioWare has developed internally to counteract the problems provoked by long-established game development practices with the ultimate goal of supporting quality localization from the start, and so guaranteeing players’ suspension of disbelief whatever the language version they playCon el objeto de lograr la inmersión absoluta en el mundo virtual del videojuego, aumentando asà la satisfacción del jugador, la localización debe conseguir el ideal de la total suspensión de la incredulidad. Sin embargo, los cortos plazos asà como cambios constantes de diseño y guión a veces obligan a que la localización tenga que cambiar calidad por velocidad, porque el cambio de las fechas de lanzamiento suele provocar pérdidas multimillonarias. Este artÃculo explica las estrategias que BioWare ha desarrollado internamente para contrarrestar los problemas provocados por las prácticas tradicionales en la industria del videojuego. El objetivo es facilitar un proceso de localización de alta calidad desde el principio del desarrollo, de modo que se garantice la suspensión de la incredulidad de los jugadores independientemente de la lengua en la que estén jugand
SALT Long-slit Spectroscopy of Luminous Obscured Quasars: An Upper Limit on the Size of the Narrow-Line Region?
We present spatially resolved long-slit spectroscopy from the Southern
African Large Telescope (SALT) to examine the spatial extent of the narrow-line
regions (NLRs) of a sample of 8 luminous obscured quasars at 0.10 < z < 0.43.
Our results are consistent with an observed shallow slope in the relationship
between NLR size and L_[OIII], which has been interpreted to indicate that NLR
size is limited by the density and ionization state of the NLR gas rather than
the availability of ionizing photons. We also explore how the NLR size scales
with a more direct measure of instantaneous AGN power using mid-IR photometry
from WISE, which probes warm to hot dust near the central black hole and so,
unlike [OIII], does not depend on the properties of the NLR. Using our results
as well as samples from the literature, we obtain a power-law relationship
between NLR size and L_8micron that is significantly steeper than that observed
for NLR size and L_[OIII]. We find that the size of the NLR goes approximately
as L^(1/2)_8micron, as expected from the simple scenario of constant-density
clouds illuminated by a central ionizing source. We further see tentative
evidence for a flattening of the relationship between NLR size and L_8micron at
the high luminosity end, and propose that we are seeing a limiting NLR size of
10 - 20 kpc, beyond which the availability of gas to ionize becomes too low. We
find that L_[OIII] ~ L_8micron^(1.4), consistent with a picture in which the
L_[OIII] is dependent on the volume of the NLR. These results indicate that
high-luminosity quasars have a strong effect in ionizing the available gas in a
galaxy.Comment: 9 Pages, 5 figures, accepted to Ap
Composite Spectral Energy Distributions and Infrared-Optical Colors of Type 1 and Type 2 Quasars
We present observed mid-infrared and optical colors and composite spectral
energy distributions (SEDs) of type 1 (broad-line) and 2 (narrow-line) quasars
selected from Sloan Digital Sky Survey (SDSS) spectroscopy. A significant
fraction of powerful quasars are obscured by dust, and are difficult to detect
in optical photometric or spectroscopic surveys. However these may be more
easily identified on the basis of mid-infrared (MIR) colors and SEDs. Using
samples of SDSS type 1 type 2 matched in redshift and [OIII] luminosity, we
produce composite rest-frame 0.2-15 micron SEDs based on SDSS, UKIDSS, and
Wide-Field Infrared Survey Explorer (WISE) photometry and perform model fits
using simple galaxy and quasar SED templates. The SEDs of type 1 and 2 quasars
are remarkably similar, with the differences explained primarily by the
extinction of the quasar component in the type 2 systems. For both types of
quasar, the flux of the AGN relative to the host galaxy increases with AGN
luminosity (L_[OIII]) and redder observed MIR color, but we find only weak
dependencies of the composite SEDs on mechanical jet power as determined
through radio luminosity. We conclude that luminous quasars can be effectively
selected using simple MIR color criteria similar to those identified previously
(W1-W2 > 0.7 [Vega]), although these criteria miss many heavily obscured
objects. Obscured quasars can be further identified based on optical-IR colors
(for example, (u-W3 [AB]) > 1.4(W1-W2 [Vega])+3.2). These results illustrate
the power of large statistical studies of obscured quasars selected on the
basis of mid-IR and optical photometry.Comment: Accepted for publication in ApJ; 14 pages, 9 figures, 2 tables;
composite Type 1 and Type 2 quasar SEDs available at
http://www.dartmouth.edu/~hickox/Hickox2017_QSO_SED_Table1.tx
The MASSIVE Survey - I. A Volume-Limited Integral-Field Spectroscopic Study of the Most Massive Early-Type Galaxies within 108 Mpc
Massive early-type galaxies represent the modern-day remnants of the earliest
major star formation episodes in the history of the universe. These galaxies
are central to our understanding of the evolution of cosmic structure, stellar
populations, and supermassive black holes, but the details of their complex
formation histories remain uncertain. To address this situation, we have
initiated the MASSIVE Survey, a volume-limited, multi-wavelength,
integral-field spectroscopic (IFS) and photometric survey of the structure and
dynamics of the ~100 most massive early-type galaxies within a distance of 108
Mpc. This survey probes a stellar mass range M* > 10^{11.5} Msun and diverse
galaxy environments that have not been systematically studied to date. Our
wide-field IFS data cover about two effective radii of individual galaxies, and
for a subset of them, we are acquiring additional IFS observations on
sub-arcsecond scales with adaptive optics. We are also acquiring deep K-band
imaging to trace the extended halos of the galaxies and measure accurate total
magnitudes. Dynamical orbit modeling of the combined data will allow us to
simultaneously determine the stellar, black hole, and dark matter halo masses.
The primary goals of the project are to constrain the black hole scaling
relations at high masses, investigate systematically the stellar initial mass
function and dark matter distribution in massive galaxies, and probe the
late-time assembly of ellipticals through stellar population and kinematical
gradients. In this paper, we describe the MASSIVE sample selection, discuss the
distinct demographics and structural and environmental properties of the
selected galaxies, and provide an overview of our basic observational program,
science goals and early survey results.Comment: 19 pages, 14 figures. ApJ (2014) vol. 795, in pres
The MASSIVE Survey II: Stellar Population Trends Out to Large Radius in Massive Early Type Galaxies
We examine stellar population gradients in ~100 massive early type galaxies
spanning 180 < sigma* < 370 km/s and M_K of -22.5 to -26.5 mag, observed as
part of the MASSIVE survey (Ma et al. 2014). Using integral-field spectroscopy
from the Mitchell Spectrograph on the 2.7m telescope at McDonald Observatory,
we create stacked spectra as a function of radius for galaxies binned by their
stellar velocity dispersion, stellar mass, and group richness. With excellent
sampling at the highest stellar mass, we examine radial trends in stellar
population properties extending to beyond twice the effective radius (~2.5
R_e). Specifically, we examine trends in age, metallicity, and abundance ratios
of Mg, C, N, and Ca, and discuss the implications for star formation histories
and elemental yields. At a fixed physical radius of 3-6 kpc (the likely size of
the galaxy cores formed at high redshift) stellar age and [alpha/Fe] increase
with increasing sigma* and depend only weakly on stellar mass, as we might
expect if denser galaxies form their central cores earlier and faster. If we
instead focus on 1-1.5 R_e, the trends in abundance and abundance ratio are
washed out, as might be expected if the stars at large radius were accreted by
smaller galaxies. Finally, we show that when controlling for \sigmastar, there
are only very subtle differences in stellar population properties or gradients
as a function of group richness; even at large radius internal properties
matter more than environment in determining star formation history.Comment: 17 pages, 9 figures, accepted by ApJ; resubmitted with updated
reference
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