A Complete Spectroscopic Survey of the Milky Way Satellite Segue 1: The Darkest Galaxy

Spectroscopic study of the Segue 1 dwarf galaxy. --author-supplied descriptio

A Complete Spectroscopic Survey of the Milky Way satellite Segue 1: Dark matter content, stellar membership and binary properties from a Bayesian analysis

We introduce a comprehensive analysis of multi-epoch stellar line-of-sight velocities to determine the intrinsic velocity dispersion of the ultrafaint satellites of the Milky Way. Our method includes a simultaneous Bayesian analysis of both membership probabilities and the contribution of binary orbital motion to the observed velocity dispersion within a 14-parameter likelihood. We apply our method to the Segue 1 dwarf galaxy and conclude that Segue 1 is a dark-matter-dominated galaxy at high probability with an intrinsic velocity dispersion of 3.7^{+1.4}_{-1.1} km/sec. The dark matter halo required to produce this dispersion must have an average density of 2.5^{+4.1}_{-1.9} solar mass/pc^3 within a sphere that encloses half the galaxy's stellar luminosity. This is the highest measured density of dark matter in the Local Group. Our results show that a significant fraction of the stars in Segue 1 may be binaries with the most probable mean period close to 10 years, but also consistent with the 180 year mean period seen in the solar vicinity at about 1 sigma. Despite this binary population, the possibility that Segue 1 is a bound star cluster with the observed velocity dispersion arising from the orbital motion of binary stars is disfavored by the multi-epoch stellar velocity data at greater than 99% C.L. Finally, our treatment yields a projected (two-dimensional) half-light radius for the stellar profile of Segue 1 of 28^{+5}_{-4} pc, in excellent agreement with photometric measurements.Comment: 15 pages, 19 figure

Recent atmospheric neutrino results from Soudan 2

An updated measurement of the atmospheric nu_mu/nu_e ratio-of-ratios, 0.68+-0.11+-0.06, has been obtained using a 4.6-kty exposure of the Soudan-2 iron tracking calorimeter. The L/E distributions have been analyzed for effects of nu_mu -> nu_x oscillations, and an allowed region in the Delta m^2 vs. sin^2 2 theta plane has been determined.Comment: 3 pages, 4 figures; presented at TAUP99, the 6th Int. Workshop on Topics in Astroparticle and Underground Physics, Sept. 6-10, 1999, College de France, Paris, Franc

Corn, 1984

Harry C. Minor is an Associate Professor of Agronomy and State Extension Specialist; Carl G. Morris is a Senior Research Specialist; and Delbert Knerr, Eric Lawman, and Virgil Sparks are Research Specialists.Includes experimental procedures, cultural practices, rainfall and temperature, charts, maps and tables and seed corn company addresses.Experimental procedures -- Cultural practices -- Rainfall and temperature -- Summary of results -- Irrigation charts -- Northern locations -- Central locations -- Southeast locations -- Irrigated locations -- Summary of entries and 1984 test locations -- Seed corn company addresses

Analyzing cropping systems (1983)

In tight financial times, businesses often try to reduce spending and improve their profits. Many farmers are currently operating their businesses under such conditions. Wise management decisions can improve profits in farming while reducing cash flow needs

Corn, 1982

Harry C. Minor is an Associate Professor of Agronomy and State Extension Specialist; Carl G. Morris is a Senior Research Specialist; and Delbert Knerr, Eric Lawman, and Virgil Sparks are Research Specialists.Compares hybrids and includes experimental procedures, cultural practices, rainfall and temperature, charts, maps and tables and seed corn company addresses.Comparing hybrids -- Experimental procedures -- Cultural practices -- Rainfall and temperature -- Summary of results -- Irrigation charts -- Northern locations -- Central locations -- Southeast locations -- Irrigated locations -- Summary of entries and 1982 test locations -- Seed corn company addresses