348 research outputs found
Investigating the complex X-ray spectrum of a broad-line 2MASS red quasar: XMM-Newton observation of FTM 0830+3759
We report results from a 50 ks XMM-Newton observation of the dust-reddened
broad-line quasar FTM 0830+3759 (z=0.413) selected from the FIRST/2MASS Red
Quasar survey. For this AGN, a very short 9 ks Chandra exposure had suggested a
feature-rich X-ray spectrum and HST images revealed a very disturbed host
galaxy morphology. Contrary to classical, optically-selected quasars, the X-ray
properties of red (i.e. with J-Ks> 1.7 and R-Ks> 4) broad line quasars are
still quite unexplored, although there is a growing consensus that, due to
moderate obscuration, these objects can offer a unique view of spectral
components typically swamped by the AGN light in normal, blue quasars. The
XMM-Newton observation discussed here has definitely confirmed the complexity
of the X-ray spectrum revealing the presence of a cold (or mildly-ionized)
absorber with Nh ~10^{22} cm^-2 along the line of sight to the nucleus and a
Compton reflection component accompanied by an intense Fe K emission line in
this quasar with a Lum(2-10) ~5 x 10^{44} erg/s. A soft-excess component is
also required by the data. The match between the column density derived by our
spectral analysis and that expected on the basis of reddening due to the dust
suggests the possibility that both absorptions occur in the same medium. FTM
0830+3759 is characterized by an extinction/absorption-corrected
X-ray-to-optical flux ratio alphaox = -2.3, that is steeper than expected on
the basis of its UV luminosity. These findings indicate that the X-ray
properties of FTM 0830+3759 differs from those typically observed for
optically-selected broad line quasars with comparable hard X-ray luminosity.Comment: Accepted for publication in Ap
HST, radio and infrared observations of 28 3CR radio galaxies at redshift z ~ 1: I. Old stellar populations in central cluster galaxies
Hubble Space Telescope images of 3CR radio galaxies at redshifts 0.6 < z <
1.8 have shown a remarkable variety of structures, generally aligned along the
radio axis, indicating that the radio source strongly influences the optical
appearance of these galaxies. In this paper we investigate the host galaxies
underlying this aligned emission, combining the HST data with ground-based
infrared images. An investigation of the spectral energy distributions of the
galaxies shows that the contribution of the aligned blue component to the
K--band light is generally small (about 10%). The radial intensity profiles of
the galaxies are well matched at radii <~ 35 kpc by de Vaucouleurs' law,
demonstrating that the K--band light is dominated by that of an elliptical
galaxy. There is no evidence for a nuclear point source, in addition to the de
Vaucouleurs profile, with a contribution >~15% of the total K--band flux
density, except in two cases, 3C22 and 3C41. Large characteristic radii are
derived, indicating that the 3CR galaxies must be highly evolved dynamically,
even at a redshift of one. At radii > 35 kpc, a combined galaxy profile clearly
shows an excess of emission reminiscent of cD--type halos. This supports other
independent evidence for the hypothesis that the distant 3CR galaxies lie in
moderately rich (proto--)clusters. Since the nearby FR II galaxies in the 3CR
catalogue lie in more diffuse environments and do not possess cD halos, the
galactic environments of the 3CR galaxies must change with redshift. The K-z
relation of the 3CR galaxies cannot, therefore, be interpreted using a standard
`closed-box, passive stellar evolution' model. We offer a new interpretation,
and compare the model with the K-z relations of lower power radio galaxies and
brightest cluster galaxies. (abridged)Comment: 21 pages including 13 figures, LaTeX. To appear in MNRA
Recommended from our members
Climatology, storm morphologies, and environments of tornadoes in the British Isles: 1980–2012
A climatology is developed for tornadoes during 1980–2012 in the British Isles, defined in this article as England, Scotland, Wales, Northern Ireland, Republic of Ireland, Channel Islands, and the Isle of Man. The climatology includes parent storm type, interannual variability, annual and diurnal cycles, intensities, oc- currence of outbreaks (defined as three or more tornadoes in the same day), geographic distribution, and environmental conditions derived from proximity soundings of tornadoes. Tornado reports are from the Tornado and Storm Research Organization (TORRO). Over the 33 years, there were a mean of 34.3 tor- nadoes and 19.5 tornado days (number of days in which at least one tornado occurred) annually. Tornadoes and tornado outbreaks were most commonly produced from linear storms, defined as radar signatures at least 75 km long and approximately 3 times as long as wide. Most (78%) tornadoes occurred in England. The probability of a tornado within 10 km of a point was highest in the south, southeast, and west of England. On average, there were 2.5 tornado outbreaks every year. Where intensity was known, 95% of tornadoes were classified as F0 or F1 with the remainder classified as F2. There were no tornadoes rated F3 or greater during this time period. Tornadoes occurred throughout the year with a maximum from May through October. Finally, tornadoes tended to occur in low-CAPE, high-shear environments. Tornadoes in the British Isles were difficult to predict using only sounding-derived parameters because there were no clear thresholds between null, tornadic, outbreak, and significant tornado cases
Cosmological evolution of the Fanaroff-Riley type II source population
By combining a model for the evolution of the radio luminosity of an
individual source with the radio luminosity function, we perform a
multi-dimensional Monte-Carlo simulation to investigate the cosmological
evolution of the Fanaroff-Riley Class II radio galaxy population by generating
large artificial samples. The properties of FRII sources are required to evolve
with redshift in the artificial samples to fit the observations. Either the
maximum jet age or the maximum density of the jet environment or both evolve
with redshift. We also study the distribution of FRII source properties as a
function of redshift. From currently available data we can not constrain the
shape of the distribution of environment density or age, but jet power is found
to follow a power-law distribution with an exponent of approximately -2. This
power-law slope does not change with redshift out to z=0.6. We also find the
distribution of the pressure in the lobes of FRII sources to evolve with
redshift up to .Comment: 22 pages, 17 figures, accepted for publication in MNRA
Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research
This review discusses the current status of supermassive black hole research,
as seen from a purely observational standpoint. Since the early '90s, rapid
technological advances, most notably the launch of the Hubble Space Telescope,
the commissioning of the VLBA and improvements in near-infrared speckle imaging
techniques, have not only given us incontrovertible proof of the existence of
supermassive black holes, but have unveiled fundamental connections between the
mass of the central singularity and the global properties of the host galaxy.
It is thanks to these observations that we are now, for the first time, in a
position to understand the origin, evolution and cosmic relevance of these
fascinating objects.Comment: Invited Review, 114 pages. Because of space requirements, this
version contains low resolution figures. The full resolution version can be
downloaded from http://www.physics.rutgers.edu/~lff/publications.htm
Crop Updates 2009 - Farming Systems
This session covers nineteen papers from different authors:
Decision support technology
1. The use of high resolution imagery in broad acre cropping, Derk Bakker and Grey Poulish, Department of Agriculture and Food
2. Spraywise decisions – online spray applicatiors planning tool, Steve Lacy, Nufarm Australia Ltd
3. Testing for redlegged earthmite resistance in Western Australia, Svetlana Micic, Peter Mangano, Tony Dore and Alan Lord, Department of Agriculture and Food
4. Screening cereal, canola and pasture cultivars for Root Lesion Nematode (Pratylenchus neglectus), Vivien Vanstone, Helen Hunter and Sean Kelly,Department of Agriculture and Food
Farming Systems Research
5. Lessons from five years of cropping systems research, WK Anderson, Department of Agriculture and Food
6. Facey Group rotations for profit: Five years on and where to next? Gary Lang and David McCarthy, Facey Group, Wickepin, WA
Mixed Farming
7. Saline groundwater use by Lucerne and its biomass production in relation to groundwater salinity, Ruhi Ferdowsian, Ian Roseand Andrew Van Burgel, Department of Agriculture and Food
8. Autumn cleaning yellow serradella pastures with broad spectrum herbicides – a novel weed control strategy that exploits delayed germination, Dr David Ferris, Department of Agriculture and Food
9. Decimating weed seed banks within non-crop phases for the benefit of subsequent crops, Dr David Ferris, Department of Agriculture and Food
10. Making seasonal variability easier to deal with in a mixed farming enterprise! Rob Grima,Department of Agriculture and Food
11. How widely have new annual legume pastures been adopted in the low to medium rainfall zones of Western Australia? Natalie Hogg, Department of Agriculture and Food, John Davis, Institute for Sustainability and Technology Policy, Murdoch University
12. Economic evaluation of dual purpose cereal in the Central wheatbelt of Western Australia, Jarrad Martin, Pippa Michael and Robert Belford, School of Agriculture and Environment, CurtinUniversity of Technology, Muresk Campus
13. A system for improving the fit of annual pasture legumes under Western Australian farming systems, Kawsar P Salam1,2, Roy Murray-Prior1, David Bowran2and Moin U. Salam2, 1Curtin University of Technology; 2Department of Agriculture and Food 14. Perception versus reality: why we should measure our pasture, Tim Scanlon, Department of Agriculture and Food, Len Wade, Charles Sturt University, Megan Ryan, University of Western Australia
Modelling
15. Potential impact of climate changes on the profitability of cropping systems in the medium and high rainfall areas of the northern wheatbelt, Megan Abrahams, Chad
Reynolds, Caroline Peek, Dennis van Gool, Kari-Lee Falconer and Daniel Gardiner, Department of Agriculture and Food
16. Prediction of wheat grain yield using Yield Prophet®, Geoff Anderson and Siva Sivapalan, Department of Agriculture and Food
17. Using Yield Prophet® to determine the likely impacts of climate change on wheat production, Tim McClelland1, James Hunt1, Zvi Hochman2, Bill Long3, Dean Holzworth4, Anthony Whitbread5, Stephen van Rees1and Peter DeVoil6 1 Birchip Cropping Group, Birchip, Vic, 2Agricultural Production Systems Research Unit (APSRU), CSIRO Sustainable Ecosystems, Climate Adaptation Flagship, Qld, 3 AgConsulting, SA 4 Agricultural Production Systems Research Unit (APSRU), CSIRO Sustainable Ecosystems, Toowoomba Qld, 5 CSIRO Sustainable Ecosystems, SA, 6 Agricultural Production Systems Research Unit (APSRU), Department of Agriculture and Fisheries, Queensland
18. Simple methods to predict yield potential: Improvements to the French and Schultz formula to account for soil type and within-season rainfall, Yvette Oliver, Michael Robertson and Peter Stone, CSIRO Sustainable Ecosystems
19. Ability of various yield forecasting models to estimate soil water at the start of the growing season, Siva Sivapalan, Kari-Lee Falconer and Geoff Anderson, Department of Agriculture and Foo
An Agent-Based Model of a Hepatic Inflammatory Response to Salmonella: A Computational Study under a Large Set of Experimental Data
Citation: Shi, Z. Z., Chapes, S. K., Ben-Arieh, D., & Wu, C. H. (2016). An Agent-Based Model of a Hepatic Inflammatory Response to Salmonella: A Computational Study under a Large Set of Experimental Data. Plos One, 11(8), 39. doi:10.1371/journal.pone.0161131We present an agent-based model (ABM) to simulate a hepatic inflammatory response (HIR) in a mouse infected by Salmonella that sometimes progressed to problematic proportions, known as "sepsis". Based on over 200 published studies, this ABM describes interactions among 21 cells or cytokines and incorporates 226 experimental data sets and/or data estimates from those reports to simulate a mouse HIR in silico. Our simulated results reproduced dynamic patterns of HIR reported in the literature. As shown in vivo, our model also demonstrated that sepsis was highly related to the initial Salmonella dose and the presence of components of the adaptive immune system. We determined that high mobility group box-1, C-reactive protein, and the interleukin-10: tumor necrosis factor-a ratio, and CD4+ T cell: CD8+ T cell ratio, all recognized as biomarkers during HIR, significantly correlated with outcomes of HIR. During therapy-directed silico simulations, our results demonstrated that anti-agent intervention impacted the survival rates of septic individuals in a time-dependent manner. By specifying the infected species, source of infection, and site of infection, this ABM enabled us to reproduce the kinetics of several essential indicators during a HIR, observe distinct dynamic patterns that are manifested during HIR, and allowed us to test proposed therapy-directed treatments. Although limitation still exists, this ABM is a step forward because it links underlying biological processes to computational simulation and was validated through a series of comparisons between the simulated results and experimental studies
Crowdsourcing hypothesis tests: Making transparent how design choices shape research results
To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div
Galaxy bulges and their massive black holes: a review
With references to both key and oft-forgotten pioneering works, this article
starts by presenting a review into how we came to believe in the existence of
massive black holes at the centres of galaxies. It then presents the historical
development of the near-linear (black hole)-(host spheroid) mass relation,
before explaining why this has recently been dramatically revised. Past
disagreement over the slope of the (black hole)-(velocity dispersion) relation
is also explained, and the discovery of sub-structure within the (black
hole)-(velocity dispersion) diagram is discussed. As the search for the
fundamental connection between massive black holes and their host galaxies
continues, the competing array of additional black hole mass scaling relations
for samples of predominantly inactive galaxies are presented.Comment: Invited (15 Feb. 2014) review article (submitted 16 Nov. 2014). 590
references, 9 figures, 25 pages in emulateApJ format. To appear in "Galactic
Bulges", E. Laurikainen, R.F. Peletier, and D.A. Gadotti (eds.), Springer
Publishin
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