The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at z∼3z\sim3

We present results of a deep spectroscopic survey designed to quantify the statistics of the escape of ionizing photons from star-forming galaxies at z~3. We measure the ratio of ionizing to non-ionizing UV flux density _obs, where f900 is the mean flux density evaluated over the range [880,910] A. We quantify the emergent ratio of ionizing to non-ionizing UV flux density by analyzing high-S/N composite spectra formed from sub-samples with common observed properties and numbers sufficient to reduce the statistical uncertainty in the modeled IGM+CGM correction to obtain precise values of _out, including a full-sample average _out=$0.057\pm0.006$. We further show that _out increases monotonically with Ly$\alpha$ rest equivalent width, inducing an inverse correlation with UV luminosity as a by-product. We fit the composite spectra using stellar spectral synthesis together with models of the ISM in which a fraction f_c of the stellar continuum is covered by gas with column density N(HI). We show that the composite spectra simultaneously constrain the intrinsic properties of the stars (L900/L1500)_int along with f_c, N(HI), E(B-V), and $f_{esc,abs}$, the absolute escape fraction of ionizing photons. We find a sample-averaged $f_{esc,abs} =0.09\pm0.01$, and that subsamples fall along a linear relation $\langle f_{esc,abs}\rangle \sim 0.75[W(Ly\alpha)/110 A]$. We use the FUV luminosity function, the distribution function $n[W(Ly\alpha)]$, and the relationship between $W(Ly\alpha)$ and _out to estimate the total ionizing emissivity of $z\sim3$ star-forming galaxies with Muv < -19.5: $\epsilon_{LyC}\sim 6\times10^{24}$ ergs/s/Hz/Mpc$^3$, exceeding the contribution of QSOs by a factor of $\sim 3$, and accounting for $\sim50$% of the total $\epsilon_{LyC}$ at $z\sim3$ estimated using indirect methods.Comment: 45 pages, 31 figures, ApJ, in pres

Correlation analysis of milk production traits across three generations of Simmental cows

The relationship between milk production traits over whole lactations was evaluated across three generations of Simmental cows (between daughters, dams and granddams) by a corelation analysis with whole lactation traits in the daughter generation being used as the dependent variables (x&lt;sub&gt;1&lt;/sub&gt;), and those in the dam and granddam generations being used as the independent variables (x&lt;sub&gt;2&lt;/sub&gt; and  x&lt;sub&gt;3&lt;/sub&gt;). The results were obtained from a sample of 1170 daughters and as many dams and  granddams. The correlation of whole lactation milk production traits between daughters, dams and  granddams, as calculated by simple, partial and multiple correlation coefficients was very weak or  non-existent. All of the calculated simple and partial correlation coefficients were positive and mostly  statistically very significant (P&lt;0.01). The calculated coefficients of multiple correlation (R1.23) between  lactation length, milk fat content, milk yield, milk fat yield and 4% FCM yield with the expression of the traits in the daughters being used as the dependent variable and that in the dams and granddams as the independent variable were statistically very significant (P&lt;0.01), amounting to 0.091, 0.251, 0.180, 0.133 and 0.153, respectively.Key words: Simmental breed, production traits, generation, coefficient of partial correlation, coefficient of multiple correlation

Time Domain Explorations With Digital Sky Surveys

One of the new frontiers of astronomical research is the exploration of time variability on the sky at different wavelengths and flux levels. We have carried out a pilot project using DPOSS data to study strong variables and transients, and are now extending it to the new Palomar-QUEST synoptic sky survey. We report on our early findings and outline the methodology to be implemented in preparation for a real-time transient detection pipeline. In addition to large numbers of known types of highly variable sources (e.g., SNe, CVs, OVV QSOs, etc.), we expect to find numerous transients whose nature may be established by a rapid follow-up. Whereas we will make all detected variables publicly available through the web, we anticipate that email alerts would be issued in the real time for a subset of events deemed to be the most interesting. This real-time process entails many challenges, in an effort to maintain a high completeness while keeping the contamination low. We will utilize distributed Grid services developed by the GRIST project, and implement a variety of advanced statistical and machine learning techniques.Comment: 5 pages, 2 postscript figures, uses adassconf.sty. To be published in: "ADASS XIV (2004)", Eds. Patrick Shopbell, Matthew Britton and Rick Ebert, ASP Conference Serie

Uticaj minazela plus na proizvodne rezultate i ekonomicnost tova junica

This paper presents the effects of the Minazel Plus zeolite product on the production performance – body weight, feed consumption and feed conversion, and economic performance of heifers in a fattening trial. The trial involved 22 female domestic spotted Simmental calves allocated to two groups (control C - ration without zeolite, and experimental E-I – ration with 0.2% Minazel Plus), each containing 11 calves with an average body weight of 139.09 kg at the beginning of the trial. The length of the trial period was 283 days. Ration included meadow hay and complete feed. Minazel Plus supplementation was provided through the feed concentrate. The trial involved measurement of body weights of heifers and feed consumption across groups at 31, 61, 91, 121, 151 and 283 days of the trial. Results showed that, at the end of the trial, control heifers had an average body weight of 432.73 kg/calf and concentrate feed conversion of 5.234 kg/kg weight gain, whereas the respective values in E-I heifers were 435.91 kg/calf and 5.179 kg/kg weight gain. The cost of the weight gain produced was higher by 0.33% (0.31 RSD/kg) in C calves than in E-I heifers, whereas the economic performance of the experimental animals receiving diet with Minazel Plus (0.2%) was higher by 0.29%.U radu su prikazani efekti zeolitskog preparata Minazel Plus na proizvodne rezultate –telesnu masu, konzumaciju i konverziju hrane i ekonomičnost tova ženske junadi u tovu. U ogledu je bilo 22 ženske teladi domaće šarene rase u tipu simentalca, podeljih u dve grupe (K grupa, obrok bez zeolitskog preparata i O-I grupa hranjena obrokom sa 0,2% Minazela Plus) sa po 11 grla u grupi, prosečne telesne mase na početku ogleda 139,09kg. Ogled je trajao 283 dana. Obrok je bio sastavljen od livadskog sena i potpune smeše, a Minazel Plus je dodavan preko koncentrovanog dela obroka. U toku ogleda merene su telesne mase junica i konzumacija hrane po grupama 31-og, 61-og, 91-og, 121-og, 150-og i na kraju ogleda - 283 dana. Rezultati istraživanja su pokazali da su junice iz kontrolne grupe na kraju ogleda imale prosečnu masu 432,73 kg/grlu i konverziju koncentrovane hrane 5,234 kg/kg prirasta, a grla iz O-I grupe prosečnu masu 435,91 kg/grlu i konverziju koncentrovane hrane 5,179 kg/kg prirasta. Cena koštanja proizvedenog prirasta bila je veća za 0,33% (0,31din/kg) kod K grupe u odnosu na O-I grupu, a u pogledu ekonomičnosti proizvodnje, ogledna grupa koja je obrokom dobijala Minazel-Plus (0,2%) imala je ekonomičniju proizvodnju za 0,29%

Quasars as Probes of Late Reionization and Early Structure Formation

Observations of QSOs at z ~ 5.7 - 6.4 show the appearance of Gunn-Peterson troughs around z ~ 6, and a change in the slope of the IGM optical depth tau(z) near z ~ 5.5. These results are interpreted as a signature of the end of the reionization era, which probably started at considerably higher redshifts. However, there also appears to be a substantial cosmic variance in the transmission of the IGM, both along some lines of sight, and among different lines of sight, in this intriguing redshift regime. We suggest that this is indicative of a spatially uneven reionization, possibly caused by the bias-driven primordial clustering of the reionization sources. There is also some independent evidence for a strong clustering of QSOs at z ~ 4 - 5 and galaxies around them, supporting the idea of the strong biasing of the first luminous sources at these redshifts. Larger samples of high-z QSOs are needed in order to provide improved, statistically significant constraints for the models of these phenomena. We expect that the Palomar-Quest (PQ) survey will soon provide a new set of QSOs to be used as cosmological probes in this redshift regime.Comment: To appear in proceedings of UC Irvine May 2005 workshop on "First Light & Reionization", eds. E. Barton & A. Cooray, New Astronomy Reviews, in pres