562 research outputs found
NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk
We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and
Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is
the first time this state has been observed in Cyg X-1 with NuSTAR, which
enables us to study the reflection and broad-band spectra in unprecedented
detail. We confirm that the iron line cannot be fit with a combination of
narrow lines and absorption features, and instead requires a relativistically
blurred profile in combination with a narrow line and absorption from the
companion wind. We use the reflection models of Garcia et al. (2014) to
simultaneously measure the black hole spin, disk inner radius, and coronal
height in a self-consistent manner. Detailed fits to the iron line profile
indicate a high level of relativistic blurring, indicative of reflection from
the inner accretion disk. We find a high spin, a small inner disk radius, and a
low source height, and rule out truncation to greater than three gravitational
radii at the 3{\sigma} confidence level. In addition, we find that the line
profile has not changed greatly in the switch from soft to hard states, and
that the differences are consistent with changes in the underlying reflection
spectrum rather than the relativistic blurring. We find that the blurring
parameters are consistent when fitting either just the iron line or the entire
broad-band spectrum, which is well modelled with a Comptonized continuum plus
reflection model.Comment: 12 pages, 7 figures, accepted for publication in Ap
Power, norms and institutional change in the European Union: the protection of the free movement of goods
How do institutions of the European Union change? Using an institutionalist approach, this article highlights the interplay between power, cognitive limits, and the normative order that underpins institutional settings and assesses their impact upon the process of institutional change. Empirical evidence from recent attempts to reinforce the protection of the free movement of goods in the EU suggests that, under conditions of uncertainty, actors with ambiguous preferences assess attempts at institutional change on the basis of the historically defined normative order which holds a given institutional structure together. Hence, path dependent and incremental change occurs even when more ambitious and functionally superior proposals are on offer
Alpha and lambda interferon together mediate suppression of CD4 T cells induced by respiratory syncytial virus
The mechanism by which respiratory syncytial virus (RSV) suppresses T-cell proliferation to itself and other antigens is poorly understood. We used monocyte-derived dendritic cells (MDDC) and CD4 T cells and measured [(3)H]thymidine incorporation to determine the factors responsible for RSV-induced T-cell suppression. These two cell types were sufficient for RSV-induced suppression of T-cell proliferation in response to cytomegalovirus or Staphylococcus enterotoxin B. Suppressive activity was transferable with supernatants from RSV-infected MDDC and was not due to transfer of live virus or RSV F (fusion) protein. Supernatants from RSV-infected MDDC, but not MDDC exposed to UV-killed RSV or mock conditions, contained alpha interferon (IFN-alpha; median, 43 pg/ml) and IFN-lambda (approximately 1 to 20 ng/ml). Neutralization of IFN-alpha with monoclonal antibody (MAb) against one of its receptor chains, IFNAR2, or of IFN-lambda with MAb against either of its receptor chains, IFN-lambdaR1 (interleukin 28R [IL-28R]) or IL-10R2, had a modest effect. In contrast, blocking the two receptors together markedly reduced or completely blocked the RSV-induced suppression of CD4 T-cell proliferation. Defining the mechanism of RSV-induced suppression may guide vaccine design and provide insight into previously uncharacterized human T-cell responses and activities of interferons
Between learning and schooling: the politics of human rights monitoring at the Universal Periodic Review
This paper explores the politics of monitoring at the Universal Periodic Review (UPR), a new United Nations human rights monitoring mechanism which aims to promote a universal approach and equal treatment when reviewing each countryâs human rights situation. To what extent are these laudable aims realised, and realisable, given entrenched representations of the West and the Rest as well as geopolitical and economic inequalities both historically and in the present? Based on ethnographic fieldwork at the UN in 2010â11, the final year of the UPRâs first cycle, we explore how these aims were both pursued and subverted, paying attention to two distinct ways of talking about the UPR: first, as a learning culture in which UN member states âshare best practiceâ and engage in constructive criticism; and second, as an exam which UN member states face as students with vastly differing attitudes and competences. Accounts and experiences of diplomats from states that are not placed in the âgood studentsâ category offer valuable insights into the inherent contradictions of de-historicised and de-contextualised approaches to human rights
The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180
We present joint \textit{XMM-Newton} and \textit{NuSTAR} observations of the
`bare' narrow line Seyfert 1 Ton S180 (), carried out in 2016 and
providing the first hard X-ray view of this luminous galaxy. We find that the
0.4--30 keV band cannot be self-consistently reproduced by relativistic
reflection models, which fail to account simultaneously for the soft and hard
X-ray emission. The smooth soft excess prefers extreme blurring parameters,
confirmed by the nearly featureless nature of the RGS spectrum, while the
moderately broad Fe K line and the modest hard excess above 10 keV appear to
arise in a milder gravity regime. By allowing a different origin of the soft
excess, the broadband X-ray spectrum and overall spectral energy distribution
(SED) are well explained by a combination of: (a) direct thermal emission from
the accretion disc, dominating from the optical to the far/extreme UV; (b)
Comptonization of seed disc photons by a warm ( keV) and
optically thick () corona, mostly contributing to the soft X-rays;
(c) Comptonization by a standard hot ( keV) and
optically thin () corona, responsible for the primary X-ray
continuum; and (d) reflection from the mid/outer part of the disc. The two
coronae are suggested to be rather compact, with R. Our SED analysis implies that Ton S180 accretes
at super-Eddington rates. This is a key condition for the launch of a wind,
marginal (i.e., 3.1 significance) evidence of which is indeed found in
the RGS spectrum.Comment: 20 pages, 12 figures. Accepted for publication MNRA
Recent advances in neutrinoless double beta decay search
Even after the discovery of neutrino flavour oscillations, based on data from
atmospheric, solar, reactor, and accelerator experiments, many characteristics
of the neutrino remain unknown. Only the neutrino square-mass differences and
the mixing angle values have been estimated, while the value of each mass
eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is
still escaping. Neutrinoless double beta decay (-DBD) experimental
discovery could be the ultimate answer to some delicate questions of elementary
particle and nuclear physics. The Majorana description of neutrinos allows the
-DBD process, and consequently either a mass value could be measured or
the existence of physics beyond the standard should be confirmed without any
doubt. As expected, the -DBD measurement is a very difficult field of
application for experimentalists. In this paper, after a short summary of the
latest results in neutrino physics, the experimental status, the R&D projects,
and perspectives in -DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic
Inclusive D* Production in Two-Photon Collisions at LEP
Inclusive D^{*+-} production in two-photon collisions is studied with the L3
detector at LEP, using 683 pb^{-1} of data collected at centre-of-mass energies
from 183 to 208 GeV. Differential cross sections are determined as functions of
the transverse momentum and pseudorapidity of the D^{*+-} mesons in the
kinematic region 1 GeV < P_T < 12 GeV and |eta| < 1.4. The cross sections
sigma(e^+e^- -> e^+e^-D^{*+-}X) in this kinematical region is measured and the
sigma(e^+e^- -> e^+e^- cc{bar}X) cross section is derived. The measurements are
compared with next-to-leading order perturbative QCD calculations
Classification and incidence of cancers in adolescents and young adults in England 1979â1997
Cancer patients aged 15â24 years have distinct special needs. High quality cancer statistics are required for service planning. Data presented by primary site are inappropriate for this age group. We have developed a morphology-based classification and applied it to national cancer registration data for England 1979â1997. The study included 25â000 cancers and 134 million personâyears at risk. Rates for each diagnostic group by age, sex and time period (1979â83, 1984â87, 1988â92, 1993â1997) were calculated. Overall rates in 15â19 and 20â24-year-olds were 144 and 226 per million personâyears respectively. Lymphomas showed the highest rates in both age groups. Rates for leukaemias and bone tumours were lower in 20â24 year olds. Higher rates for carcinomas, central nervous system tumours, germ-cell tumours, soft tissue sarcomas and melanoma were seen in the older group. Poisson regression showed incidence increased over the study period by an average of 1.5% per annum (P<0.0001). Significant increases were seen in non-Hodgkins lymphoma (2.3%), astrocytoma (2.3%), germ-cell tumours (2.3%), melanoma (5.1%) and carcinoma of the thyroid (3.5%) and ovary (3.0%). Cancers common in the elderly are uncommon in adolescents and young adults. The incidence of certain cancers in the latter is increasing. Future studies should be directed towards aetiology
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