Broadband modified turnstile antenna Patent

Broadband modified turnstile antenna for use in space tracking and communication

Improved modified turnstile antenna

Improved antenna design embodies the principles of turnstiling, broadbanding, and delta dipole matching. Antenna is useful in commercial broadcast applications

On the Spin Bias of Satellite Galaxies in the Local Group-like Environment

We utilize the Millennium-II simulation databases to study the spin bias of dark subhalos in the Local Group-like systems which have two prominent satellites with comparable masses. Selecting the group-size halos with total mass similar to that of the Local Group (LG) from the friends-of-friends halo catalog and locating their subhalos from the substructure catalog, we determine the most massive (main) and second to the most massive (submain) ones among the subhalos hosted by each selected halo. When the dimensionless spin parameter (lambda) of each subhalo is derived from its specific angular momentum and circular velocity at virial radius, a signal of correlation is detected between the spin parameters of the subhalos and the main-to-submain mass ratios of their host halos at z=0: The higher main-to-submain mass ratio a host halo has, the higher mean spin parameter its subhalos have. It is also found that the correlations exist even for the subhalo progenitors at z=0.5 and z=1. Our interpretation of this result is that the subhalo spin bias is not a transient effect but an intrinsic property of a LG-like system with higher main-to- submain mass ratio, caused by stronger anisotropic stress in the region. A cosmological implication of our result is also discussed.Comment: Accepted for publication in JCAP, 15 pages, 12 figures, dimensionless spin parameter of each subhalo determined from its circular velocity measured at the virial radius, the correlations between the spin parameters of the subhalo progenitors and the main-to-submain mass ratios of their descendant hosts newly determined, minor mistakes correcte

Information of Structures in Galaxy Distribution

We introduce an information-theoretic measure, the Renyi information, to describe the galaxy distribution in space. We discuss properties of the information measure, and demonstrate its relationship with the probability distribution function and multifractal descriptions. Using the First Look Survey galaxy samples observed by the Infrared Array Camera onboard Spitzer Space Telescope, we present measurements of the Renyi information, as well as the counts-in-cells distribution and multifractal properties of galaxies in mid-infrared wavelengths. Guided by multiplicative cascade simulation based on a binomial model, we verify our measurements, and discuss the spatial selection effects on measuring information of the spatial structures. We derive structure scan functions at scales where selection effects are small for the Spitzer samples. We discuss the results, and the potential of applying the Renyi information to measuring other spatial structures.Comment: 25 pages, 8 figures, submitted to ApJ; To appear in The Astrophysical Journal 2006, 644, 678 (June 20th

Typifications in Andersonia (Ericaceae: Epacridoideae)

Lectotypes are selected for Andersonia R.Br (Ericaceae) and eight taxa within the genus: A. aristata Lindl. A. brevifolia Sond., A. heterophylla Sond., A. involucrata Sond., A. sprengelioides R.Br., A. lehmanniana subsp. lehmanniana (Sond.)L.Watson and A. lehmanniana subsp. pubescens (Sond.)L.Watson. Andersonia patens Sond. is lectotypified in synonymy with A. sprengelioides