We use a dynamical systems approach to study thawing quintessence models, using a multiparameter extension of the exponential potential which can approximate the form of typical thawing potentials. ...We impose observational constraints using a compilation of current data, and forecast the tightening of constraints expected from future dark energy surveys, as well as discussing the relation of our results to analytical constraints already in the literature.
Objective:
To gain an experiential account of the processes of change associated specifically with orthognathic surgery. Design: A qualitative design was used. Semistructured interviews were carried ...out with 7 participants approximately 1 week before and 6-8 weeks after surgery. The data were analyzed using interpretative phenomenologic analysis (IPA).
Setting:
Participants were recruited from a NHS Dental Hospital. Participants: Patients aged 16 to 25 years scheduled to undergo orthognathic surgery on both the upper and lower jaws were purposively sought to participate. Seven participants aged between 18 and 25 years and who had undergone a bimaxillary osteotomy completed interviews (5 females and 2 males).
Results:
Themes were identified in connection with the overall journey of treatment being a rite of passage; the treatment’s role in raising awareness about the anomalies in appearance; the initial shock at the changes that followed surgery; the uncertainty about treatment; the impact of actual negative reactions of others; and the role of significant others in the decision-making process.
Conclusions:
Participants described undergoing a much more complex process of adjustment to change in appearance than has been identified elsewhere within the literature, and the study highlights the nuanced fashion in which both medical and parental communication influence patient expectation and experience of surgery. There is a need to improve communication between clinicians, families, and young adults seeking orthognathic surgery. Further studies are needed to investigate the processes associated with seeking to change facial appearance resulting from other forms of dentofacial condition.
We report the discovery of XMMXCS J2215.9-1738, a massive galaxy cluster at z = 1.45, which was found in the XMM Cluster Survey. The cluster candidate was initially identified as an extended X-ray ...source in archival XMM data. Optical spectroscopy shows that six galaxies within a 660 diameter region lie at z = 1.45 c 0.01. Model fits to the X-ray spectra of the extended emission yield kT = 7.4 sub(-1.8) super(+2.7) keV (90% confidence); if there is an undetected central X-ray point source, then kT = 6.5 sub(-1.8) super(+2.6) keV. The bolometric X-ray luminosity is L sub(X) = 4.4 sub(-0.6) super(+0.8) x 10 super(44) ergs s super(-1) over a 2 Mpc radial region. The measured T sub(X), which is the highest for any known cluster at z > 1, suggests that this cluster is relatively massive for such a high redshift. The redshift of XMMXCS J2215.9-1738 is the highest currently known for a spectroscopically confirmed cluster of galaxies.
We present a direct measurement of the mean halo occupation distribution (HOD) of galaxies taken from the eleventh data release (DR11) of the Sloan Digital Sky Survey-III Baryon Oscillation ...Spectroscopic Survey (BOSS). The HOD of BOSS low-redshift (LOWZ: 0.2 < z < 0.4) and Constant-Mass (CMASS: 0.43 < z < 0.7) galaxies is inferred via their association with the dark matter haloes of 174 X-ray-selected galaxy clusters drawn from the XMM Cluster Survey (XCS). Halo masses are determined for each galaxy cluster based on X-ray temperature measurements, and range between log sub( 10)(M sub( 180)/M...) = 13 and 15. Our directly measured HODs are consistent with the HOD-model fits inferred via the galaxy-clustering analyses of Parejko et al. for the BOSS LOWZ sample and White et al. for the BOSS CMASS sample. Under the simplifying assumption that the other parameters that describe the HOD hold the values measured by these authors, we have determined a best-fitting alpha-index of 0.91 plus or minus 0.08 and 1.27... for the CMASS and LOWZ HOD, respectively. These alpha-index values are consistent with those measured by White et al. and Parejko et al. In summary, our study provides independent support for the HOD models assumed during the development of the BOSS mock-galaxy catalogues that have subsequently been used to derive BOSS cosmological constraints. (ProQuest: ... denotes formulae/symbols omitted.)
This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and ...stellar populations of their fossil galaxies. In total, 17 groups and clusters are identified at z < 0.25 with large magnitude gaps between the first and fourth brightest galaxies. All the information necessary to classify these systems as fossils is provided. For both groups and clusters, the total and fractional luminosity of the brightest galaxy is positively correlated with the magnitude gap. The brightest galaxies in FSs (called fossil galaxies) have stellar populations and star formation histories which are similar to normal brightest cluster galaxies (BCGs). However, at fixed group/cluster mass, the stellar masses of the fossil galaxies are larger compared to normal BCGs, a fact that holds true over a wide range of group/cluster masses. Moreover, the fossil galaxies are found to contain a significant fraction of the total optical luminosity of the group/cluster within 0.5 R sub(200), as much as 85%, compared to the non-fossils, which can have as little as 10%. Our results suggest that FSs formed early and in the highest density regions of the universe and that fossil galaxies represent the end products of galaxy mergers in groups and clusters.
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