29,850 research outputs found
United States budgetary costs of Post-9/11 wars through FY2018
Originally published on the Watson Institute's Costs of War Project website: http://watson.brown.edu/costsofwar/papers/2017/USBudgetaryCostsFY2018The costs to the United States of post-9/11 wars will total more than 23,386 on these wars since 2001. âThe U.S. wars in Iraq, Syria, Afghanistan and Pakistan, and the increased spending on homeland security and the departments of defense, state and veterans affairs since the 9/11 attacks have cost more than 5.6 trillion.
Optical integral field spectroscopy of the extended line emission around six radio-loud quasars
We present integral field spectroscopy of a small sample of radio-loud
quasars at intermediate redshift (0.26<z<0.60), most of which are associated
with large radio sources. All have oxygen line emission extended over tens of
kiloparcsecs, and these nebulae display a diverse range in both morphology and
kinematic behaviour. Two quasars show 'plumes' of extended line emission, two
show a clumpy structure and a further one shows a smooth distribution. There is
no clear pattern with regard to the distribution of the ionized gas in relation
to the radio source axis; the extended emission-line regions are found both
parallel and perpendicular - and also totally unrelated to - the radio axis.
The velocity structure of the ionized gas ranges from essentially static to
apparent smooth rotation, and in two cases, show a clear association with the
radio source. Given the disparity in properties, the nebulae all show a
surprisingly similar ionization state, as measured by the extended lines of
[OII] and [OIII]. Assuming the gas is ionized by at least the nearby quasar
nucleus, we use the emission line ratios to infer a pressure in the ionized
gas; in all cases we find it to be at high pressure, suggesting confinement by
an external (probably intracluster) medium.Comment: 14 pages, 18 figures, 10 of which are presented separately; accepted
for publication in MNRA
Noise requirements from a military point of view
External and internal aircraft noise requirements are discussed in terms of application to military helicopters. The impact of the application of noise reduction technology to comply with FAA standards on cost and performance is emphasized
Extended X-ray emission around four 3C quasars at 0.55<z<0.75 observed with Chandra
We report on the detection of a soft spatially-extended component of X-ray
emission around four intermediate-redshift 3C quasars observed with Chandra:
3C254, 3C263, 3C275.1 and 3C281. The bolometric luminosity of this emission
ranges over 0.3-1.6 times 10^{44}erg/s, and extends to lengthscales of over 350
kpc at the redshift of the quasar. The X-rays are most likely thermal emission
from the intracluster medium of a cluster of galaxies around each quasar, which
provides the working surface for the powerful radio lobes. Some X-ray emission
is also seen to be associated with the radio plasma.Comment: 8 pages, 4 panelled figures, MNRAS in pres
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