636 research outputs found
From Service to Experience: Understanding and Defining the Hospitality Business
Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the hostâguest relationship, generosity, theatre and performance, âlots of little surprisesâ, and the security of strangers â a focus that provides guests with experiences that are personal, memorable and add value to their lives
Do broad absorption line quasars live in different environments from ordinary quasars?
We select a sample of traditionally defined broad absorption line
quasars (BALQs) from the Fifth Data Release quasar catalog of the Sloan Digital
Sky Survey. For a statistically homogeneous quasar sample with , the BAL quasar fraction is and is almost constant with
redshift. We measure the auto-correlation of non-BAL quasars (nonBALQs) and the
cross-correlation of BALQs with nonBALQs using this statistically homogeneous
sample, both in redshift space and using the projected correlation function. We
find no significant difference between the clustering strengths of BALQs and
nonBALQs. Assuming a power-law model for the real space correlation function
, the correlation length for nonBALQs is ; for BALQs, the cross-correlation length is . Our clustering results suggest that BALQs live in similar
large-scale environments as do nonBALQs.Comment: accepted for publication in Ap
Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64
We present a moderate-resolution (~20 km/s) spectrum of the mini
broad-absorption-line QSO PG1351+64 between 915-1180 A, obtained with the Far
Ultraviolet Spectroscopic Explorer (FUSE). Additional spectra at longer
wavelengths were also obtained with the HST and ground-based telescopes. Broad
absorption is present on the blue wings of CIII 977, Ly-beta, OVI 1032,1038,
Ly-alpha, NV 1238,1242, SiIV 1393,1402, and CIV 1548,1450. The absorption
profile can be fitted with five components at velocities of ~ -780, -1049,
-1629, -1833, and -3054 km/s with respect to the emission-line redshift of z =
0.088. All the absorption components cover a large fraction of the continuum
source as well as the broad-line region. The OVI emission feature is very weak,
and the OVI/Lyalpha flux ratio is 0.08, one of the lowest among low-redshift
active galaxies and QSOs. The UV continuum shows a significant change in slope
near 1050 A in the restframe. The steeper continuum shortward of the Lyman
limit extrapolates well to the observed weak X-ray flux level. The absorbers'
properties are similar to those of high-redshift broad absorption-line QSOs.
The derived total column density of the UV absorbers is on the order of 10^21
cm^-2, unlikely to produce significant opacity above 1 keV in the X-ray. Unless
there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux
may be intrinsic. The ionization level of the absorbing components is
comparable to that anticipated in the broad-line region, therefore the
absorbers may be related to broad-line clouds along the line of sight.Comment: 23 pages, Latex, 5 figure
FUSE Observations of Intrinsic Absorption in the Seyfert 1 Galaxy Mrk 509
We present far-ultraviolet spectra of the Seyfert 1 galaxy Mrk 509 obtained
in 1999 November with the Far Ultraviolet Spectroscopic Explorer (FUSE). Our
data span the observed wavelength range 915-1185 A at a resolution of ~20 km/s.
The spectrum shows a blue continuum, broad OVI 1032,1038 emission, and a broad
CIII 977 emission line. Superposed on these emission components, we resolve
associated absorption lines of OVI 1032,1038, CIII 977, and Lyman lines through
Lzeta. Seven distinct kinematic components are present, spanning a velocity
range of -440 to +170 km/s relative to the systemic velocity. The absorption is
clustered in two groups, one centered at -370m km/s and another at the systemic
velocity. The blue-shifted cluster may be associated with the extended line
emission visible in deep images of Mrk 509 obtained by Phillips et al. Although
several components appear to be saturated, they are not black at their centers.
Partial covering or scattering permits ~7% of the broad-line or continuum flux
to be unaffected by absorption. Of the multiple components, only one has the
same ionization state and column density as highly ionized gas that produces
the OVII and OVIII ionization edges in X-ray spectra of Mrk 509.
This paper will appear in a special issue of Astrophysical Journal Letters
devoted to the first scientific results from the FUSE mission.Comment: To appear in the Astrophysical Journal (Letters). 4 pages, 3 color
PostScript figures. Figures are best viewed and printed in color. Added
acknowledgment that this is one of many papers to be published in a special
issue of ApJL devoted to the first scientific results from the FUSE missio
The role of black hole mass in quasar radio activity
We use a homogeneous sample of about 300, 0.3 <~ z <~ 3, radio-loud quasars
drawn from the FIRST and 2dF QSO surveys to investigate a possible dependence
of radio activity on black-hole mass. By analyzing composite spectra for the
populations of radio-quiet and radio-loud QSOs -- chosen to have the same
redshift and luminosity distribution -- we find with high statistical
significance that radio-loud quasars are on average associated with black holes
of masses ~10^{8.6} M_sun, about twice as large as those measured for
radio-quiet quasars (~10^{8.3} M_sun). We also find a clear dependence of black
hole mass on optical luminosity of the form log (M_BH/M_sun)_{RL}= 8.57(\pm
0.06) - 0.27(\pm 0.06) (M_B + 24.5) and log (M_BH/M_sun)_{RQ}= 8.43(\pm 0.05)
-0.32(\pm 0.06) (M_B + 24.5), respectively for the case of radio-loud and
radio-quiet quasars. It is intriguing to note that these two trends run roughly
parallel to each other, implying that radio-loud quasars are associated to
black holes more massive than those producing the radio-quiet case at all
sampled luminosities. On the other hand, in the case of radio-loud quasars, we
find evidence for only a weak (if any) dependence of the black hole mass on
radio power. The above findings seem to support the belief that there exists --
at a given optical luminosity -- a threshold black hole mass associated with
the onset of significant radio activity such as that of radio-loud QSOs;
however, once the activity is triggered, there appears to be very little
connection between black hole mass and level of radio output.Comment: 10 pages, 10 figures, minor changes to match the accepted versio
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