4,545 research outputs found
WP 32 - Tax evasive behaviour and gender in a transition country
In this paper, we provide a structural explanation of gender difference with respect to tax evasion. A unique data set, collected from a field survey of households in Albania, allows us to test and explore the established fact, in a transition country. The results show that women tend to evade taxes less than men, even after controlling for socio-economic and demographic characteristics (e.g., age, family status, education, income). Starting from neo-institutional theory, the paper analyzes the explanatory power of this theory where it concerns the differences in men’s and women’s tax behavior. Acknowledging the fact that gender differences in economic behavior are generally explained either as biological or by social/psychological role theory, this paper also discusses possible explanations as suggested in feminist economic research. Using the data available, some main hypothesis are articulated, tested and evaluated.
Introduction: Exploring feminist ecological economics
These Explorations argue that more links between the fields of feminist ecology
and feminist economics are both needed and promising, and presents new,
boundary-crossing research in this area. It brings together contributions from
various regions in the world that link political action and experience in practice
and research in an economic theorizing that includes both environmental and
feminist concerns.This research was supported by the Social Sciences and Humanities Research Council of Canad
A search for 183-GHz emission from water in late-type stars
A search was made for 183 GHz line emission from water vapor in the direction of twelve Mira and two semiregular variables. Upper limits to the emission are in the range of 2000 to 5000 Jy. It is estimated that thermal emission from the inner regions of late type stellar envelopes will be on the order of ten Jy. Maser emission, according to one model, would be an order of magnitude stronger. From the limited set sampled, the possibility of very strong maser emission at 183 GHz cannot yet be ruled out
A general hybrid radiation transport scheme for star formation simulations on an adaptive grid
Radiation feedback plays a crucial role in the process of star formation. In
order to simulate the thermodynamic evolution of disks, filaments, and the
molecular gas surrounding clusters of young stars, we require an efficient and
accurate method for solving the radiation transfer problem. We describe the
implementation of a hybrid radiation transport scheme in the adaptive
grid-based FLASH general magnetohydrodynamics code. The hybrid scheme splits
the radiative transport problem into a raytracing step and a diffusion step.
The raytracer captures the first absorption event, as stars irradiate their
environments, while the evolution of the diffuse component of the radiation
field is handled by a flux-limited diffusion (FLD) solver. We demonstrate the
accuracy of our method through a variety of benchmark tests including the
irradiation of a static disk, subcritical and supercritical radiative shocks,
and thermal energy equilibration. We also demonstrate the capability of our
method for casting shadows and calculating gas and dust temperatures in the
presence of multiple stellar sources. Our method enables radiation-hydrodynamic
studies of young stellar objects, protostellar disks, and clustered star
formation in magnetized, filamentary environments.Comment: 16 pages, 15 figures, accepted to Ap
Accreting millisecond X-ray pulsars: 10 years of INTEGRAL observations
During the last 10 years, INTEGRAL made a unique contribution to the study of
accreting millisecond X-ray pulsars (AMXPs), discovering three of the 14
sources now known of this class. Besides increasing the number of known AMXPs,
INTEGRAL also carried out observations of these objects above 20 keV,
substantially advancing our understanding of their behaviour. We present here a
review of all the AMXPs observed with INTEGRAL and discuss the physical
interpretation of their behaviour in the X-ray domain. We focus in particular
on the lightcurve profile during outburst, as well as the timing, spectral, and
thermonuclear type-I X-ray bursts properties.Comment: 8 pages, 8 figures. Proceedings of "An INTEGRAL view of the
high-energy sky (the first 10 years)" the 9th INTEGRAL Workshop, October
15-19, 2012, Paris, Franc
INTEGRAL and RXTE observations of accreting millisecond pulsar IGR J00291+5934 in outburst
Simultaneous observations of the accretion-powered millisecond pulsar IGR
J00291+5934 by International Gamma-Ray Astrophysics Laboratory and Rossi X-ray
Timing Explorer during the 2004 December outburst are analysed. The average
spectrum is well described by thermal Comptonization with an electron
temperature of 50 keV and Thomson optical depth tau_T ~ 1 in a slab geometry.
The spectral shape is almost constant during the outburst. We detect a spin-up
of the pulsar with nudot=8.4x10E-13 Hz/s. The ISGRI data reveal the pulsation
of X-rays at a period of 1.67 milliseconds up to ~150 keV. The pulsed fraction
is shown to increase from 6 per cent at 6 keV to 12--20 per cent at 100 keV.
This is naturally explained by the action of the Doppler effect the
exponentially cutoff Comptonization spectrum from the hot spot. The nearly
sinusoidal pulses show soft lags with complex energy dependence, increasing up
to 7 keV, then decreasing to 15 keV, and seemingly saturating at higher
energies.Comment: 11 pages, 8 figures, 3 tables, accepted for publication on A&
183 GHz water line variation: An energetic outburst in orion KL
Observations of the 3(13)-2(20) transition of water vapor in the direction of Ori MC1 in 1980 February show a 50% flux increase and an apparent additional red shift of approximately 2 km/s relative to the line observed in 1977 December. From a detailed examination of the amplitude and frequency calibration, it appears unlikely that the effect is due to systematic error. The increase is attributed to the appearance of a new component at a velocity of 12 km/s with respect to the local standard of rest. The new component also has broad wings. Increased emission from a region in the high-velocity core of Ori MC1 can be due either to additional far-IR radiation to pump the 1983 GHz transition or to a change in the physical conditions in the gas. Statistical equilibrium calculations using the large-velocity-gradient formalism were carried out to develop a model for the emission. The calculations support a model in which the gas in the region of enhanced emission is hotter than the dust. The temporal coincidence between the 183 GHZ increase and the 22 GH1 water maser outburst suggests a common, impulsive cause, which has heated the gas in a part of the HV source, enhancing the emission in both transitions
Hierarchical fragmentation and collapse signatures in a high-mass starless region
Aims: Understanding the fragmentation and collapse properties of the dense
gas during the onset of high-mass star formation. Methods: We observed the
massive (~800M_sun) starless gas clump IRDC18310-4 with the Plateau de Bure
Interferometer (PdBI) at sub-arcsecond resolution in the 1.07mm continuum
andN2H+(3-2) line emission. Results: Zooming from a single-dish low-resolution
map to previous 3mm PdBI data, and now the new 1.07mm continuum observations,
the sub-structures hierarchically fragment on the increasingly smaller spatial
scales. While the fragment separations may still be roughly consistent with
pure thermal Jeans fragmentation, the derived core masses are almost two orders
of magnitude larger than the typical Jeans mass at the given densities and
temperatures. However, the data can be reconciled with models using
non-homogeneous initial density structures, turbulence and/or magnetic fields.
While most sub-cores remain (far-)infrared dark even at 70mum, we identify weak
70mum emission toward one core with a comparably low luminosity of ~16L_sun,
re-enforcing the general youth of the region. The spectral line data always
exhibit multiple spectral components toward each core with comparably small
line widths for the individual components (in the 0.3 to 1.0km/s regime). Based
on single-dish C18O(2-1) data we estimate a low virial-to-gas-mass ratio
<=0.25. We discuss that the likely origin of these spectral properties may be
the global collapse of the original gas clump that results in multiple spectral
components along each line of sight. Even within this dynamic picture the
individual collapsing gas cores appear to have very low levels of internal
turbulence.Comment: 8 pages, 4 figures, A&A in pres
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