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In response to increased international collaboration in archaeological research of the South Caucases, a recent workshop has addressed important issues in applying GIS to the study of heavily modified landscapes in the former Soviet republics of Armenia, Azerbaijan and Georgia.
We compare the host galaxies of 902 supernovae, including Type Ia, II and Ibc, which are selected by cross-matching the Asiago Supernova Catalog with the SDSS DR7. We further selected 213 galaxies by requiring the light fraction of spectral observations > 15%, which could represent well the global properties of the galaxies. The diagrams related to Dn(4000), HδA, stellar masses, SFRs and specific SFRs for the SNe hosts show that almost all SNe II and most of SNe Ibc occur in SF galaxies. A significant fraction of SNe Ia occurs in AGNs and Absorp galaxies. These results are compared with those of the 689 comparison galaxies where the SDSS fiber captures < 15% of the total light. These comparison galaxies appear biased towards higher 12+log(O/H) (~0.1dex) at a given stellar mass, suggesting the aperture effect should be kept in mind when the properties of the hosts for different types of SNe are discussed.
Based on the Sloan Digital Sky Survey DR 7, we investigate the environment, morphology, and stellar population of bulgeless low surface-brightness (LSB) galaxies in a volume-limited sample with redshift ranging from 0.024 to 0.04 and Mr ≤ −18.8. We find that, for bulgeless galaxies, the surface brightness does not depend on the environment. Irregular LSB galaxies have more young stars and are more metal-poor than regular LSB galaxies. These results suggest that the evolution of LSB galaxies may be driven by their dynamics, including mergers rather than by their large-scale environment.
In this study, we investigated variation in offspring size (OS) of Daphnia magna in relation to multiple maternal traits and environmental variables. Data originated from laboratory experiments conducted at different feeding scenarios. The mother daphnids had different life-history traits and were reared under various feeding and density conditions. OS showed linear relationships with maternal traits, varying positively with maternal body size, age and brood number, and negatively with brood size and with the amount of ingested carbon. OS increased exponentially with crowding. Using stepwise multiple regression analysis, we developed an empirical model for the OS variation with the relevant maternal and environmental variables. Density dependence was considered by multiplying the resulting model by a density-effect function. We found that the ingested carbon and the maternal body size were the strongest determinants of the observed variation in the OS, whereas the brood size had the least impact on OS. Additionally, the brood number had no significant effect in determining the variability in the OS. The validity of the multivariate model was tested against an independent dataset. The model accurately predicted the OS despite several genetic and environmental differences compared with the data used for parameterization.
To report a rare case of delayed endovascular coil extrusion following embolisation of a lingual artery pseudoaneurysm.
A 23-year-old woman presented with dysphagia and odynophagia 11 months after having experienced massive post-tonsillectomy haemorrhage. At that time, the bleeding had been stopped by embolisation of a lingual artery pseudoaneurysm and the external carotid artery. Clinical examination at admission showed extrusion of the embolisation coils in the lateral lower pharyngeal wall. The coils were removed under general anaesthesia in the presence of an interventional radiologist. The procedure and post-operative period were without complication and no bleeding was observed. The dysphagia and pain disappeared and the subsequent seven-month follow-up period was uneventful.
Although selective embolisation is a safe and effective treatment for severe post-tonsillectomy haemorrhage, the possibility of delayed coil extrusion should be kept in mind.
We study and compare the stellar populations of host galaxies of different types of supernovae (SNe): SN Ia and core collapse SN (SN II and SN Ibc) at the same time. The 234 sample galaxies are selected by cross-matching the Asiago Supernova Catalogue (ASC) and the SDSS-DR7 main galaxy sample (MGS). The STARLIGHT software is used to analyze their stellar populations by fitting the continua and absorption lines of the hosts.
We investigated a scenario in which M31 could be the remnant of a major merger and at the origin of the LMC. Galaxy merger simulations were run in order to reproduce some M31 properties. We succeeded in reproducing some of the most important M31 large-scale features like the thick disk or the polar ring, and gave a possible explanation for the formation of the Giant Stream. We also found that the LMC could be expelled by this high energetic phenomenon.
Scaling relations are salient ingredients of galaxy evolution and formation models. I summarize results from the IMAGES survey, which combines spatially-resolved kinematics from FLAMES/GIRAFFE with imaging from HST/ACS and other facilities. Specifically, I will focus on the evolution of the stellar mass and baryonic Tully-Fisher Relations (TFR) from z = 0.6 down to z = 0. We found a significant evolution in zero point and scatter of the stellar mass TFR compared to the local Universe. Combined with gas fractions derived by inverting the Schmidt-Kennicutt relation, we derived for the first time a baryonic TFR at high redshift. Conversely to the stellar mass TFR, the baryonic relation does not appear to evolve in zero point, which suggests that most of the reservoir of gas converted into stars over the past 6 Gyr was already gravitationally bound to galaxies at z = 0.6.
We present results of a project aimed at establishing a set of 12 spectro-photometric standards over a wide wavelength range from 320 to 2500 nm. Currently no such set of standard stars covering the near-IR is available. Our strategy is to extend the useful range of existing well-established optical flux standards (Oke 1990, Hamuy et al. 1992, 1994) into the near-IR by means of integral field spectroscopy with SINFONI at the VLT combined with state-of-the-art white dwarf stellar atmospheric models (TMAP, Holberg et al. 2008). As a solid reference, we use two primary HST standard white dwarfs GD71 and GD153 and one HST secondary standard BD+17 4708. The data were collected through an ESO “Observatory Programme” over ~40 nights between February 2007 and September 2008.
We have gathered a representative sample of 88 intermediate mass galaxies at z~0.6 and have provided robust estimates of their gas phase metallicity based on the strong line method R23. We have found that these galaxies have undergone a strong evolution of their metal content during the last 8 Gyrs. We confirmed the shift about ~0.3dex to lower abundance of the M-Z relation at z~0.6 found by Liang et al. 2006. This result shows that the evolution of the gas phase is still active down to z=0.4 and that the close box model is not a valid scenario for local spiral progenitors.
A large sample of low surface brightness (LSB) disk galaxies is selected from SDSS with B-band central surface brightness μ0(B) from 22 to 24.5 mag arcsec−2. Some of their properties are studied, such as magnitudes, surface brightness, scalelengths, colors, metallicities, stellar populations, stellar masses and multiwavelength SEDs from UV to IR etc. These properties of LSB galaxies have been compared with those of the galaxies with higher surface brightnesses. Then we check the variations of these properties following surface brightness.
The stellar populations of 849 local infrared-selected galaxies from SDSS and IRAS (including 419 star-forming galaxies, 326 composite galaxies, 35 Seyfert 2s, and 69 LINERs in 4 spectral classes) are studied by using STARLIGHT. Among the 4 spectral classes, the importance of young populations decreases from star-forming, composite, Seyfert 2 to LINER; and Seyfert 2 and LINER are more metal-rich; ULIGs (ultra luminous infrared galaxies) & LIGs present the youngest populations among 3 infrared luminosity bins; and normal galaxies are more metal-rich. The dominant contributors to masses are all old populations.
We compare six evolutionary population synthesis (EPS) models, which have been popularly used in stellar populations analyses for galaxies. The resulted stellar populations of star-forming galaxies and E+A galaxies from these EPS models show that the dominated contribution (fraction) from young, intermediate and old populations to their lights are consistent, although the individual numbers may change significantly, 3-30%, which could relate to the different ingredients in EPS models, such as the stellar library, the stellar evolution tracks etc.
The stellar mass-metallicity relations of star-forming galaxies at intermediate-z (0.4<z<1) and high-z (z≥2) are compared with the local SDSS galaxies. It shows obvious evolutionary effect, i.e., at a given stellar mass, the intermediate-z galaxies show about 0.3 dex lower metallicity, and the high-z galaxies show about 0.56 dex more metal-deficient than the local ones. These distant galaxies will produce these important parts of their metals during the consequent evolutionary process. A close-box model can explain this evolutionary process generally.
Using a large sample of ~40,000 star-forming galaxies selected from the SDSS, we derive oxygen abundance calibrations from strong-line ratios, such as [N II]/Hα, [O III]/[N II], [N II]/[O II], [N II]/[S II], [S II]/Hα, and [O III]/Hβ. The derived analytic calibrations cover a quite wide range of metallicity, from 12+log(O/H)= 7.1 to 9.3. These calibrations can be used as calibration references for the future studies about metallicities of star-forming galaxies.
We have used the FLAMES multi-integral field unit system of the European Southern Observatory (VLT) centered on the cluster MS0451.6-0305 at z = 0.5386 to obtain the spatially resolved kinematics of the cluster members. The spectral data are supported by HST/ACS images that provide immediate morphological information of the cluster galaxies. The relevant structural parameters such as inclination, size, and orientation derived from optical high angular resolution images are compared with those derived from the kinematics. Our final goals are: 1. to derive the Tully-Fisher relation for cluster galaxies with regular kinematics. 2. to obtain the dynamical masses from resolved kinematics and stellar masses from optical images to be compared with local measurements.
The color purity of blue polyfluorene fluorescence emission is often adversely contaminated by green emission bands. The origin of this green emission has been attributed to various factors including on-chain oxidation of fluorene leading to monomeric fluorenone emission and inter/intra-chain interaction between segments of fluorenone units leading to excimer formation on the polyfluorene backbone. We report here emission properties at the bulk and single molecule level of a molecular fluorene derivative and compare them to those of its oxidative fluorenone derivative. Whereas the bulk fluorescence emission of 2,7-bis(3,4,5-trimethoxyphenylethenyl)-9,9-diethyl-9H-fluorene (OFPV) exhibits a blue to blue-green emission at about 480 nm, 2,7-bis(3,4,5-trimethoxyphenylethenyl)-9,9-diethyl-9H-fluorenone (OFOPV) shows red luminescence with a peak centered at about 630 nm. However, the peak position for OFOPV shifts to higher energies (∼540 nm) upon dilution or dispersion in polymer matrices like PMMA or Zeonex. Single molecule measurements of OFOPV show fluorescence spectra dominated by peaks around 540 nm, with a small minority at longer wavelengths that are attributed to emission from dimers or higher aggregates. This distribution indicates that monomeric emission of OFOPV is green, consistent with green emission bands seen in polyfluorenes.