Population III by Popular Demand - Progress and Previews

I discuss the ongoing search for stars of the Milky Way which have been referred to as members of Population III. Following a discussion of possible definitions for these stars, I consider the reasons why astronomers have undertaken this search, and list some of the numerous astrophysical uses of the extremely metal-poor stars found along the way. I then review survey techniques which have been used in the past, and provide an update on plans for future investigations. Finally, the question of when one might consider the search for Population III Finished is addressed.Comment: 12 pages, 0 figures, to appear in proceedings of THE FIRST STARS meeting, held in Garching, Germany, August 199

Searches for the Most Metal-Poor Candidates from SDSS and SEGUE

We report on efforts to identify large samples of very and extremely metal-poor stars based on medium-resolution spectroscopy and ugriz photometry obtained during the course of the Sloan Digital Sky Survey (SDSS), and its extension, SDSS-II, which includes the program SEGUE: Sloan Extension for Galactic Understanding and Exploration. To date, over 8000 stars with [Fe/H] <= -2.0 and effective temperatures in the range 4500K < T_eff < 7000K have been found, with the expected numbers in this temperature range to be well over 10,000 once SEGUE is completed. The numbers roughly double when one includes warmer blue stragglers and Blue Horizontal-Branch (BHB) stars in these counts. We show the observed low-metallicity tails of the Metallicity Distribution Functions for the cooler SDSS/SEGUE stars obtained thus far. We also comment on the confirmation of an inner/outer halo dichotomy in the Milky Way, and on how this realization may be used to direct searches for even more metal-poor stars in the near future.Comment: 5 pages, 4 figures, from the conference "First Stars III", held in July 200

The stellar content of the Hamburg/ESO survey. IV. Selection of candidate metal-poor stars

We present the quantitative methods used for selecting candidate metal-poor stars in the Hamburg/ESO objective-prism survey (HES). The selection is based on the strength of the Ca II K line, B-V colors (both measured directly from the digital HES spectra), as well as J-K colors from the 2 Micron All Sky Survey. The KP index for Ca II K can be measured from the HES spectra with an accuracy of 1.0 Angstrom, and a calibration of the HES B-V colors, using CCD photometry, yields a 1-sigma uncertainty of 0.07 mag for stars in the color range 0.3 < B-V < 1.4. These accuracies make it possible to reliably reject stars with [Fe/H] > -2.0 without sacrificing completeness at the lowest metallicities. A test of the selection using 1121 stars of the HK survey of Beers, Preston, and Shectman present on HES plates suggests that the completeness at [Fe/H] < -3.5 is close to 100% and that, at the same time, the contamination of the candidate sample with false positives is low: 50% of all stars with [Fe/H] > -2.5 and 97% of all stars with [Fe/H] > -2.0 are rejected. The selection was applied to 379 HES fields, covering a nominal area of 8853 square degrees of the southern high Galactic latitude sky. The candidate sample consists of 20,271 stars in the magnitude range 10 < B < 18. A comparison of the magnitude distribution with that of the HK survey shows that the magnitude limit of the HES sample is about 2 mag fainter. Taking the overlap of the sky areas covered by both surveys into account, it follows that the survey volume for metal-poor stars has been increased by the HES by about a factor of 10 with respect to the HK survey. We have already identified several very rare objects with the HES, including, e.g., the three most heavy-element deficient stars currently known.Comment: 11 pages, 10 figures, accepted for publication in A&

Enterprise Systems Adoption and Firm Performance in Europe: The Role of Innovation

Despite the ubiquitous proliferation and importance of Enterprise Systems (ES), little research exists on their post-implementation impact on firm performance, especially in Europe. This paper provides representative, large-sample evidence on the differential effects of different ES types on performance of European enterprises. It also highlights the mediating role of innovation in the process of value creation from ES investments. Empirical data on the adoption of Enterprise Resource Planning (ERP), Supply Chain Management (SCM), Customer Relationship Management (CRM), Knowledge Management System (KMS), and Document Management System (DMS) is used to investigate the effects on product and process innovation, revenue, productivity and market share growth, and profitability. The data covers 29 sectors in 29 countries over a 5-year period. The results show that all ES categories significantly increase the likelihood of product and process innovation. Most of ES categories affect revenue, productivity and market share growth positively. Particularly, more domainspecific and simpler system types lead to stronger positive effects. ERP systems decrease the profitability likelihood of the firm, whereas other ES categories do not show any significant effect. The findings also imply that innovation acts as a full or partial mediator in the process of value creation of ES implementations. The direct effect of enterprise software on firm performance disappears or significantly diminishes when the indirect effects through product and process innovation are explicitly accounted for. The paper highlights future areas of research.Enterprise Systems; ERP; SCM; CRM; KMS; DMS; IT Adoption; Post-implementation Phase; IT Business Value; Innovation; Firm Performance; Europe