823 research outputs found
6C radio galaxies at z~1: The influence of radio power on the alignment effect
Powerful radio galaxies often display enhanced optical/UV continuum emission
and extended emission line regions, elongated and aligned with the radio jet
axis. The expansion of the radio source strongly affects the gas clouds in the
surrounding IGM, and the kinematic and ionization properties of the extended
emission line regions display considerable variation over the lifetime of
individual sources, as well as with cosmic epoch. We present the results of
deep rest-frame UV and optical imaging and UV spectroscopy of high redshift 6C
radio galaxies. The interdependence of the host galaxy and radio source
properties are discussed, considering: (i) the relative contribution of shocks
associated with the expanding radio source to the observed emission line gas
kinematics, and their effect on the ionization state of the gas; (ii) the
similarities and differences between the morphologies of the host galaxies and
aligned emission for a range of radio source powers; and (iii) the influence of
radio power on the strength of the observed alignment effect.Comment: LaTeX, 6 pages, 5 figures, Elsevier Science format. To appear in
"Radio galaxies: past, present & future". eds. M. Jarvis et al., Leiden, Nov
200
Exploring effective information use in an insurance workplace
As employability has become a more visible graduate attribute, it is becoming recognised that a better understanding of information practices in work may enable a smoother transition from university to employment. This paper discusses the current state of workplace information literacy and presents the findings of research into staff experiences of information use in a City insurance firm. A framework previously developed out of phenomenographic research into nursing is employed to draw parallels and highlight differences between insurance workplace and university student terminology. Context-specific hierarchical statements using the language of the participants are developed from coded interview texts. These statements, which are drawn together in illustrative personae, provide a rich and detailed view of the participants’ experience of effective information use. It is suggested that a better understanding of language use in communities of practice would facilitate transition both between and within the communities
Letter from John S. (J.S.) Inskip to James B. Finley
J.S. Inskip writes to Finley concerning his recent trial at the 1851 Ohio Conference. For the second year, Inskip has been censured for allowing men and women to sit together in pews ( promiscuous seating ) during worship. Inskip has a copy of the proceedings and will be appealing to the 1852 General Conference. He would like Finley\u27s assistance. [Note: Finley is supportive of promiscuous seating, to the displeasure of many colleagues. This is a separate issue from free pews. ] Abstract Number - 471https://digitalcommons.owu.edu/finley-letters/1669/thumbnail.jp
HST and UKIRT imaging observations of z ~ 1 6C radio galaxies - I. The data
The results of Hubble Space Telescope and UKIRT imaging observations are
presented for a sample of 11 6C radio galaxies with redshifts 0.85 < z < 1.5.
The observations of the 6C sources reveal a variety of different features,
similar to those observed around the higher luminosity of the aligned emission
appears less extreme in the case of the 6C radio galaxies. For both samples,
the aligned emission clearly cannot be explained by a single emission
mechanism; line emission and related nebular continuum emission, however, often
provide a significant contribution to the aligned emission.Comment: 17 pages, 11 figures (figs 3,6,11 low resolution - full resolution
images can be obtained from http://www.mrao.cam.ac.uk/~kji/ImagingFigs/).
Accepted for publication in MNRA
Recommended from our members
Creative professional users musical relevance criteria
Although known item searching for music can be dealt with by searching metadata using existing text search techniques, human subjectivity and variability within the music itself make it very difficult to search for unknown items. This paper examines these problems within the context of text retrieval and music information retrieval. The focus is on ascertaining a relationship between music relevance criteria and those relating to relevance judgements in text retrieval. A data-rich collection of relevance judgements by creative professionals searching for unknown musical items to accompany moving images using real world queries is analysed. The participants in our observations are found to take a socio-cognitive approach and use a range of content and context based criteria. These criteria correlate strongly with those arising from previous text retrieval studies despite the many differences between music and text in their actual content
Letter from John S. (J.S.) Inskip to James B. Finley
Inskip is indignant over the treatment of Finley in his old age. Members of the Ohio Conference opposed to promiscuous seating have been unmerciful in their criticism of Finley for championing the idea of family seating. Inskip is convinced that the Ohio Conference accusers will meet with failure at General Conference. [He was right]. Finley Chapel at Dayton has changed its name to Raper Chapel in order to honor the memory of Rev. Raper. Inskip\u27s accusers are spreading the rumor that the church no longer wishes to bear Finley\u27s name due to his support of promiscuous seating. Inskip reassures Finley that this was not the reason for the name change. He is hopeful that Finley will be able to attend General Conference in Boston. Abstract Number - 1224https://digitalcommons.owu.edu/finley-letters/2204/thumbnail.jp
Deep spectroscopy of z~1 6C radio galaxies - II. Breaking the redshift-radio power degeneracy
The results of a spectroscopic analysis of 3CR and 6C radio galaxies at
redshift z~1 are contrasted with the properties of lower redshift radio
galaxies, chosen to be matched in radio luminosity to the 6C sources studied at
z~1, thus enabling the P-z degeneracy to be broken. Partial rank correlations
and principal component analysis have been used to determine which of z and P
are the critical parameters underlying the observed variation of the ionization
state andd kinematics of the emission line gas. [OII]/H-beta is shown to be a
useful ionization mechanism diagnostic. Statistical analysis of the data shows
that the ionization state of the emission line gas is strongly correlated with
radio power, once the effects of other parameters are removed. No dependence of
ionization state on z is observed, implying that the ionization state of the
emission line gas is solely a function of the AGN properties rather than the
hostt galaxy and/or environment. Statistical analysis of the kinematic
properties of the emission line gas shows that these are strongly correlated
independently withh both P and z. The correlation with redshift is the stronger
of the two, suggesting that host galaxy composition or environment may play a
role in producing the less extreme gas kinematics observed in the emission line
regions of low redshift galaxies. For both the ionization and kinematic
properties of thee galaxies, the independent correlations observed with radio
size are strongest. Radio source age is a determining factor for the extended
emission line regions.Comment: 10 pages, 5 figures, accepted for publication in MNRA
HST and UKIRT imaging observations of z~1 6C radio galaxies - II. Galaxy morphologies and the alignment effect
(abridged) Powerful radio galaxies often display enhanced optical/UV emission
regions, elongated and aligned with the radio jet axis. The aim of this series
of papers is to separately investigate the effects of radio power and redshift
on the alignment effect, together with other radio galaxy properties. In this
second paper, we present a deeper analysis of the morphological properties of
these systems, including both the host galaxies and their surrounding aligned
emission. The host galaxies of our 6C subsample are well described as de
Vaucouleurs ellipticals, with typical scale sizes of ~10kpc. This is comparable
to the host galaxies of low-z radio sources of similar powers, and also the
more powerful 3CR sources at the same redshift. The contribution of nuclear
point source emission is also comparable, regardless of radio power. The 6C
alignment effect is remarkably similar to that seen around more powerful 3CR
sources at the same redshift in terms of extent and degree of alignment with
the radio source axis, although it is generally less luminous. The bright,
knotty features observed in the case of the z~1 3CR sources are far less
frequent in our 6C subsample; neither do we observe such strong evidence for
evolution in the strength of the alignment effect with radio source size/age.
However, we do find a very strong link between the most extreme alignment
effects and emission line region properties indicative of shocks, regardless of
source size/age or power. In general, the 6C alignment effect is still
considerably stronger than that seen around lower redshift galaxies of similar
radio powers. (abridged)Comment: 23 pages, 15 figures, accepted for publication in MNRAS. See
http://www.mrao.cam.ac.uk/~kji/MorphPaper/ for version of paper with full
resolution images of Figs 1-1
Deviations from passive evolution - star formation and the UV excess in z~1 radio galaxies
Galaxy colours are determined for two samples of 6C and 3CR radio sources at
z~1, differing by a factor of ~6 in radio power. Corrections are made for
emission line contamination and the presence of any nuclear point source, and
the data analysed as a function of both redshift and the radio source
properties. The galaxy colours are remarkably similar for the two populations,
and the UV excess evolves with radio source size similarly in both samples,
depsite the fact that the alignment effect is more extensive for the more
powerful 3CR radio galaxies. These results seem to suggest that the alignment
effect at these redshifts does not scale strongly with radio power, and is
instead more closely dependent on galaxy mass (which is statistically
comparable for the two samples). However, it is likely that the presence of
relatively young (< several 10^8 years old) stellar populations has
considerably contaminated the K-band flux of these systems, particularly in the
case of the more powerful 3CR sources, which are ~0.5mag more luminous than the
predictions of passive evolution models at z~1. The higher luminosity of the
3CR alignment effect is balanced by emission at longer wavelengths, thereby
leading to comparable colours for the two samples.Comment: Accepted for publication in MNRAS. 16 pages, 9 figure
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