9,933 research outputs found
Study of a colliding laser-produced plasma by analysis of time and space-resolved image spectra
The interaction of two counter-propagating laser-produced plasmas was studied using simultaneous
imaging and spectroscopic techniques. Spectrally-filtered time-gated ICCD imaging was used
to obtain information about the spatial dynamics and temporal evolution of the collision process.
While, time-resolved imaging spectroscopy was used to determine the spatial and temporal distributions
of electron temperature and density within the interaction region. We examine specifically
the interaction of plasmas whose parameters match those typically used in pulsed laser deposition
of thin films. These low temperature plasmas are highly collisional leading to the creation of a
pronounced stagnation layer in the interaction region
The effect of divorce laws on divorce rates in Europe
This paper analyzes a panel of 18 European countries spanning from 1950 to 2003 to examine the extent to which the legal reforms leading to âeasier divorceâ that took place during the second half of the 20th century have contributed to the increase in divorce rates across Europe. We use a quasi-experimental set-up and exploit the different timing of the reforms in divorce laws across countries. We account for unobserved country-specific factors by introducing country fixed effects, and we include country-specific trends to control for time-varying factors at the country level that may be correlated with divorce rates and divorce laws, such as changing social norms or slow moving demographic trends. We find that the reforms were followed by significant increases in divorce rates. Overall, we estimate that the introduction of no-fault, unilateral divorce increased the divorce rate by about 1, a sizeable effect given the average rate of 4.2 divorces per 1,000 married people in 2002.Divorce rates, legislation
Massive young stellar object W42-MME: The discovery of an infrared jet using VLT/NACO near-infrared images
We report on the discovery of an infrared jet from a deeply embedded infrared
counterpart of 6.7 GHz methanol maser emission (MME) in W42 (i.e. W42-MME). We
also investigate that W42-MME drives a parsec-scale H2 outflow, with detection
of bow shock feature at ~0.52 pc to the north. The inner ~0.4 pc part of the H2
outflow has a position angle of ~18 deg and the position angle of ~40 deg is
found farther away on either side of outflow from W42-MME. W42-MME is detected
at wavelengths longer than 2.2 microns and is a massive young stellar object,
with the estimated stellar mass of 19+-4 Msun. We map the inner circumstellar
environment of W42-MME using VLT/NACO adaptive optics Ks and L' observations at
resolutions ~0.2 arcsec and ~0.1 arcsec, respectively. We discover a collimated
jet in the inner 4500 AU using the L' band, which contains prominent Br alpha
line emission. The jet is located inside an envelope/cavity (extent ~10640 AU)
that is tapered at both ends and is oriented along the north-south direction.
Such observed morphology of outflow cavity around massive star is scarcely
known and is very crucial for understanding the jet-outflow formation process
in massive star formation. Along the flow axis, which is parallel to the
previously known magnetic field, two blobs are found in both the NACO images at
distances of ~11800 AU, located symmetrically from W42-MME. The observed
W42-MME jet-outflow configuration can be used to constrain the jet launching
and jet collimation models in massive star formation.Comment: 6 pages, 5 figures, Accepted for publication in The Astrophysical
Journa
Analysis of the Inter-basin Water Transfer Scheme in India: a case study of the Godavari-Krishna link
River basin managementRiver basin developmentDevelopment projectsWater availab ilityWater demandWater transferDamsCanalsCrop management
Multi-wavelength study of the star-formation in the S237 H II region
We present a detailed multi-wavelength study of observations from X-ray,
near-infrared to centimeter wavelengths to probe the star formation processes
in the S237 region. Multi-wavelength images trace an almost sphere-like shell
morphology of the region, which is filled with the 0.5--2 keV X-ray emission.
The region contains two distinct environments - a bell-shaped cavity-like
structure containing the peak of 1.4 GHz emission at center, and elongated
filamentary features without any radio detection at edges of the sphere-like
shell - where {\it Herschel} clumps are detected. Using the 1.4 GHz continuum
and CO line data, the S237 region is found to be excited by a radio
spectral type of B0.5V star and is associated with an expanding H{\sc ii}
region. The photoionized gas appears to be responsible for the origin of the
bell-shaped structure. The majority of molecular gas is distributed toward a
massive {\it Herschel} clump (M 260 M), which
contains the filamentary features and has a noticeable velocity gradient. The
photometric analysis traces the clusters of young stellar objects (YSOs) mainly
toward the bell-shaped structure and the filamentary features. Considering the
lower dynamical age of the H\,{\sc ii} region (i.e. 0.2-0.8 Myr), these
clusters are unlikely to be formed by the expansion of the H\,{\sc ii} region.
Our results also show the existence of a cluster of YSOs and a massive clump at
the intersection of filamentary features, indicating that the collisions of
these features may have triggered cluster formation, similar to those found in
Serpens South region.Comment: 21 pages, 14 figures, 1 table, Accepted for publication in The
Astrophysical Journa
Constraining the Accretion Geometry of the Intermediate Polar EX Hya Using NuSTAR, Swift, and Chandra Observations
In magnetically accreting white dwarfs, the height above the white dwarf surface where the standing shock is formed is intimately related with the accretion rate and the white dwarf mass. However, it is difficult to measure. We obtained new data with NuSTAR and Swift that, together with archival Chandra data, allow us to constrain the height of the shock in the intermediate polar EX Hya. We conclude that the shock has to form at least at a distance of about one white dwarf radius from the surface in order to explain the weak Fe Kα 6.4 keV line, the absence of a reflection hump in the high-energy continuum, and the energy dependence of the white dwarf spin pulsed fraction. Additionally, the NuSTAR data allowed us to measure the true, uncontaminated hard X-ray (12-40 keV) flux, whose measurement was contaminated by the nearby galaxy cluster Abell 3528 in non-imaging X-ray instruments.Fil: Luna, Gerardo Juan Manuel. Consejo Nacional de InvestigaciĂłnes CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de AstronomĂa y FĂsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomĂa y FĂsica del Espacio; ArgentinaFil: Mukai, K.. National Aeronautics and Space Administration; Estados UnidosFil: Orio, M.. UniversitĂ di Padova; ItaliaFil: Zemko, P.. UniversitĂ di Padova; Itali
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