593 research outputs found
The Impact of Family Economic Structure on Dual-Earnersâ Career and Family Satisfaction
The present study builds on the explanatory power of the âdoing genderâ perspective to understand the effects of family economic structure on the family and career satisfaction of husbands and wives. Using data from a two-panel, couple-level survey of full-time employed middle-class families in the Northeastern United States, we find that when wivesâ earnings increase relative to their husbandsâ, their career satisfaction significantly increases whereas their husbandsâ is significantly depressed. In contrast, family economic structure has little effect on womenâ and menâs level of family satisfaction, although we find a significant reduction in family satisfaction among couples who have recently shifted towards a more equal-earner economic structure. Our findings underscore the importance of considering both husbandsâ and wivesâ attitudes towards work and career in understanding how âgender is doneâ in couples, and in addressing the resulting family and work relations and dynamics. Focusing on the disjuncture between longstanding gender norms and current employment and earning patterns, we highlight the potential impact of these findings for couples, counselors, and organizations
Itinerant-electron Ferromagnetism in W(Nb)O3-d
The crystal structure and the magnetic properties of the W1-xNbxO3-d,
(x<0.03) system have been investigated. In contrast to the orthorhombic
diamagnetic WO3, the material with x=0.01 is paramagnetic down to 5 K.
Introducing of 2.5 at. % of Nb into WO3 leads to a tetragonal structure and to
a weak itinerant ferromagnetic ordering below TC= 225 K. The saturation
magnetic moment at 5 K is 1.07*10-3 mB, whereas the paramagnetic effective
moment is 0.06 mB per mole. This high ratio indicates itinerant ferromagnetism
in W0.975Nb0.025O3-d.Comment: accepted to Physica
GRB060218 as a Tidal Disruption of a White Dwarf by an Intermediate Mass Black Hole
A highly unusual pair of a gamma-ray burst (GRB) GRB060218 and an associated
supernova SN2006aj has puzzled theorists for years. A supernova shock breakout
and a jet from a newborn stellar mass compact object were put forward to
explain its multiwavelength signature. We propose that the source is naturally
explained by another channel, a tidal disruption of a white dwarf (WD) by an
intermediate mass black hole (IMBH). The tidal disruption is accompanied by a
tidal pinching, which leads to the ignition of a WD and a supernova. Some
debris falls back onto the IMBH, forms a disk, which quickly amplifies the
magnetic field, and launches a jet. We successfully fit soft X-ray spectrum
with the Comptonized blackbody emission from a jet photosphere. The optical/UV
emission is consistent with self-absorbed synchrotron from the expanding jet
front. The accretion rate temporal dependence Mdot(t) in a tidal disruption
provides a good fit to soft X-ray lightcurve. The IMBH mass is found to be
about 10^4Msun in three independent estimates: (1) fitting tidal disruption
Mdot(t) to soft X-ray lightcurve; (2) computing the jet base radius in a jet
photospheric emission model; (3) inferring the central BH mass based on a host
dwarf galaxy stellar mass. The supernova position is consistent with the center
of the host galaxy, while low supernova ejecta mass is consistent with a WD
mass. High expected rate of tidal disruptions in dwarf galaxies is consistent
with one source observed by Swift satellite over several years at GRB060218
distance of 150Mpc. The encounters with the WDs provide a lot of fuel for IMBH
growth.Comment: 15 pages, 5 figures, accepted to ApJ, minor change
Time dependent numerical model for the emission of radiation from relativistic plasma
We describe a numerical model constructed for the study of the emission of
radiation from relativistic plasma under conditions characteristic, e.g., to
gamma-ray bursts (GRB's) and active galactic nuclei (AGN's). The model solves
self consistently the kinetic equations for e^\pm and photons, describing
cyclo-synchrotron emission, direct Compton and inverse Compton scattering, pair
production and annihilation, including the evolution of high energy
electromagnetic cascades. The code allows calculations over a wide range of
particle energies, spanning more than 15 orders of magnitude in energy and time
scales. Our unique algorithm, which enables to follow the particle
distributions over a wide energy range, allows to accurately derive spectra at
high energies, >100 \TeV. We present the kinetic equations that are being
solved, detailed description of the equations describing the various physical
processes, the solution method, and several examples of numerical results.
Excellent agreement with analytical results of the synchrotron-SSC model is
found for parameter space regions in which this approximation is valid, and
several examples are presented of calculations for parameter space regions
where analytic results are not available.Comment: Minor changes; References added, discussion on observational status
added. Accepted for publication in Ap.
Rate of Convergence for Cardyâs Formula
We show that crossing probabilities in 2D critical site percolation on the triangular lattice in a piecewise analytic Jordan domain converge with power law rate in the mesh size to their limit given by the CardyâSmirnov formula. We use this result to obtain new upper and lower bounds of e[superscript O(âlog logR)] R[superscript -1/3] for the probability that the cluster at the origin in the half-plane has diameter R, improving the previously known estimate of R [superscript â1/3+o(1)].Natural Sciences and Engineering Research Council of Canada. Postdoctoral ScholarshipNational Science Foundation (U.S.). Graduate Research Fellowship Program (Award 1122374
The Correlation of Spectral Lag Evolution with Prompt Optical Emission in GRB 080319B
We report on observations of correlated behavior between the prompt gamma-ray
and optical emission from GRB 080319B, which confirm that (i) they occurred
within the same astrophysical source region and (ii) their respective radiation
mechanisms were dynamically coupled. Our results, based upon a new CCF
methodology for determining the time-resolved spectral lag, are summarized as
follows. First, the evolution in the arrival offset of prompt gamma-ray photon
counts between Swift-BAT 15-25 keV and 50-100 keV energy bands (intrinsic
gamma-ray spectral lag) appears to be anti-correlated with the arrival offset
between prompt 15-350 keV gamma-rays and the optical emission observed by
TORTORA (extrinsic optical/gamma-ray spectral lag), thus effectively
partitioning the burst into two main episodes at ~T+28+/-2 sec. Second, the
rise and decline of prompt optical emission at ~T+10+/-1 sec and ~T+50+/-1 sec,
respectively, both coincide with discontinuities in the hard to soft evolution
of the photon index for a power law fit to 15-150 keV Swift-BAT data at
~T+8+/-2 sec and ~T+48+/-1 sec. These spectral energy changes also coincide
with intervals whose time-resolved spectral lag values are consistent with
zero, at ~T+12+/-2 sec and ~T+50+/-2 sec. These results, which are robust
across heuristic permutations of Swift-BAT energy channels and varying temporal
bin resolution, have also been corroborated via independent analysis of
Konus-Wind data. This potential discovery may provide the first observational
evidence for an implicit connection between spectral lags and GRB emission
mechanisms in the context of canonical fireball phenomenology. Future work
includes exploring a subset of bursts with prompt optical emission to probe the
unique or ubiquitous nature of this result.Comment: 6 pages, 3 figures. Contributed to the Proceedings of the Sixth
Huntsville GRB Symposium. Edited by C.A. Meegan, N. Gehrels, and C.
Kouvelioto
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