K band Spectroscopy of Ultraluminous Infrared Galaxies: The 2 Jy Sample

We present near-infrared spectroscopy for a complete sample of 33 ultraluminous infrared galaxies at a resolution of R\approx 1000. Most of the wavelength range from 1.80-2.20 microns in the rest frame is covered, including the Pa-alpha and Br-gamma hydrogen recombination lines, and the molecular hydrogen vibration-rotation 1-0 S(1) and S(3) lines. Other species, such as He I, [Fe II], and [Si VI] appear in the spectra as well, in addition to a number of weaker molecular hydrogen lines. Nuclear extractions for each of the individual galaxies are presented here, along with spectra of secondary nuclei, where available. The Pa-alpha emission is seen to be highly concentrated on the nuclei, typically with very little emision extending beyond a radius of 1 kpc. Signatures of active nuclei are rare in the present sample, occurring in only two of the 33 galaxies. It is found that visual extinctions to the nuclei via the Pa-alpha/Br-gamma line ratio in excess of 10 magnitudes are relatively common among ULIRGs, and that visual extinctions greater than 25 mag are necessary to conceal a QSO emitting half the total bolometric luminosity. The vibration-rotation lines of molecular hydrogen appear to be predominantly thermal in origin, with effective temperatures generally around 2200 K. The relative nuclear velocities between double nucleus ULIRGs are investigated, through which it is inferred that the maximum deprojected velocity difference is about 200 km/s. This figure is lower than the velocities predicted by physical models of strong interactions/mergers of large, gas-rich galaxies.Comment: 52 pages (19 with just figures), 9 figures, accepted for publication in the Astronomical Journal; Table 3 not formatted properly on astro-ph: get source and print Murphy.tab3.p

Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation : part 2, alkaline earth elements as tracers of watershed hydrochemistry and provenance

This study demonstrates that alkaline earth elements in enamel of hippopotamids, in particular Ba and Sr, are tracers for water provenance and hydrochemistry in terrestrial settings. The studied specimens are permanent premolar and molar teeth found in modern and fossil lacustrine sediments of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–2150 μg g−1). The variations are partially induced during post-mortem alteration and during amelogenesis, but the major contribution originates ultimately from the variable water chemistry in the habitats of the hippopotamids which is controlled by the lithologies and weathering processes in the watershed areas. Amelogenesis causes a distinct distribution of MgO, Ba and Sr in modern and fossil enamel, in that element concentrations increase along profiles from the outer rim towards the enamel–dentin junction by a factor of 1.3–1.9. These elements are well correlated in single specimens, thus suggesting that their distribution is determined by a common, single process, which can be described by closed system Rayleigh crystallization of bioapatite in vivo. Enamel from most hippopotamid specimens has Sr/Ca and Ba/Ca which are typical for herbivores. However, Ba/Sr ranges from 0.1 to 3 and varies on spatial and temporal scales. Thus, Sr concentrations and Ba/Sr in enamel differentiate between habitats having basaltic mantle rocks or Archean crustal rocks as the ultimate sources of Sr and Ba. This provenance signal is modulated by climate change. In Miocene to Pleistocene enamel from the Lake Albert region, Ba/Sr decreases systematically with time from 2 to 0.5. This trend can be correlated with changes in climate from humid to arid, in vegetation from C3 to C4 biomass as well as with increasing evaporation of the lake water. The most plausible explanation is that Ba mobility decreased with increasing aridification due to preferential deposition with clay and Fe-oxide-hydroxide or barite on the watershed of Lake Albert

Improved characterisation of intra-night optical variability of prominent AGN classes

The incidence of intra-night optical variability (INOV) is known to to differ significantly among different classes of powerful active galactic nuclei (AGN). A number of statistical methods have been employed in the literature for testing the presence of INOV in the light curves, sometimes leading to discordant results. In this paper we compare the INOV characteristics of six prominent classes of AGN, as evaluated using three commonly used statistical tests, namely the $\chi^2-$test, the modified $C-$test and the $F-$test, which has recently begun to gain popularity. The AGN classes considered are: radio-quiet quasars (RQQs), radio-intermediate quasars (RIQs), lobe-dominated quasars (LDQs), low optical polarization core-dominated quasars (LPCDQs), high optical polarization core-dominated quasars (HPCDQs), and TeV blazars. Our analysis is based on a large body of AGN monitoring data, involving 262 sessions of intra-night monitoring of a total 77 AGN, using 1-2 metre class optical telescopes located in India. In order to compare the usefulness of the statistical tests, we have also subjected them to a `sanity check' by comparing the number of false positives yielded by each test with the corresponding statistical prediction. The present analysis is intended to serve as a benchmark for future INOV studies of AGN of different classes.Comment: 26 pages, 2 tables, Accepted for publication in MNRA

Electrocardiographic repolarization-related variables as predictors of coronary heart disease death in the women's health initiative study.

BackgroundWe evaluated 25 repolarization-related ECG variables for the risk of coronary heart disease (CHD) death in 52 994 postmenopausal women from the Women's Health Initiative study.Methods and resultsHazard ratios from Cox regression were computed for subgroups of women with and without cardiovascular disease (CVD). During the average follow-up of 16.9 years, 941 CHD deaths occurred. Based on electrophysiological considerations, 2 sets of ECG variables with low correlations were considered as candidates for independent predictors of CHD death: Set 1, Ѳ(Tp|Tref), the spatial angle between T peak (Tp) and normal T reference (Tref) vectors; Ѳ(Tinit|Tterm), the angle between the initial and terminal T vectors; STJ depression in V6 and rate-adjusted QTp interval (QTpa); and Set 2, TaVR and TV1 amplitudes, heart rate, and QRS duration. Strong independent predictors with over 2-fold increased risk for CHD death in women with and without CVD were Ѳ(Tp|Tref) >42° from Set 1 and TaVR amplitude >-100 μV from Set 2. The risk for these CHD death predictors remained significant after multivariable adjustment for demographic/clinical factors. Other significant predictors for CHD death in fully adjusted risk models were Ѳ(Tinit|Tterm) >30°, TV1 >175 μV, and QRS duration >100 ms.ConclusionsѲ(Tp|Tref) angle and TaVR amplitude are associated with CHD mortality in postmenopausal women. The use of these measures to identify high-risk women for further diagnostic evaluation or more intense preventive intervention warrants further study.Clinical trial registration urlhttp://www.clinicaltrials.gov. Unique identifier: NCT00000611

Wind data from the 250-foot /76.2-meter/ tower at Wallops Island, Virginia

Statistical evaluation of sampled wind data from anemometers mounted on meteorological tower on Wallops Islan

An updated survey of globular clusters in M31. II Newly discovered bright and remote clusters

We present the first results of a large spectroscopic survey of candidate globular clusters located in the extreme outskirts of the nearby M31 galaxy. We obtained low resolution spectra of 48 targets selected from the XSC of 2MASS, as in Galleti et al. (2005). The observed candidates have been robustly classified according to their radial velocity and by verifying their extended/point-source nature from ground-based optical images. Among the 48 observed candidates clusters we found 5 genuine remote globular clusters. One of them has been already identified independently by Mackey et al. (2007), their GC1; the other four are completely new discoveries: B516, B517, B518, B519. The newly discovered clusters lie at projected distance 40 kpc<~R_p<~100 kpc from the center of M31, and have absolute integrated magnitude -9.5<M_V<-7.5. For all the observed clusters we have measured the strongest Lick indices and we have obtained spectroscopic metallicity estimates. Mackey-GC1, Martin-GC1, B517 and B518 have spectra typical of old and metal poor globular clusters ([Fe/H]<~ -1.3); B519 appears old but quite metal-rich ([Fe/H]~-0.5); B516 presents very strong Balmer absorption lines: if this is indeed a cluster it should have a relatively young age (likely <2 Gyr). The present analysis nearly doubles the number of M31 globulars at R_p> 40 kpc. At odds with the Milky Way, M31 appears to have a significant population of very bright globular clusters in its extreme outskirts.Comment: 16 pages including 6 pages published only in the electronic edition of the Journal. Accepted for publication in A&

Evaluation of emmer wheat genetics resources aimed at dietary food production

Emmer wheat cultivated by organic farmers is used as a component of some bio (organic) food products. Its positive influence on consumer health is caused by grain composition. In the set of 8 emmer wheat accessions, the main grain components, bread making characteristics and contents of health supporting chemical substances such as total dietary fibre content and its components, content of total polyphenols plus catechin and ferulic acid contents, vitamins of the B group and E plus total content of carotenoids were evaluated by standard methods

Electrochemistry of Dihalogenated Nicotonic Acids in Aqueous and Aprotic Media

The electrochemical reduction of several 2,5- and 5,6- dihalonicotinic acids have been studied in dimethyl sulfoxide as well as in aqueous buffers of different pH. The polarographic half-wave potentials for the reduction of these compounds in both media are reported here. The compounds appear to reduce at the carboxyl group. The presence of halogen atoms on the pyridine ring facilitates reduction