Robust particle outline extraction and its application to digital on-line holography

Peer reviewedPostprin

The Party’s Cancelled

Senior Project submitted to The Division of Languages and Literature of Bard College

VALIDACION DE ALGUNAS RECIENTES NOVEDADES TAXONOMICAS EN ERIOSYCE PHIL. (CACTACEAE

A. E. Hoffmann & H. E. Walter (2004) published taxonomic novelties invalidly in the latest edition of their book onCactaceae in Chile. It also contained an orthographical inaccuracy. All these occur in the genus Eriosyce as revised andexpanded by Katterman (1994). They are rectified here with the colaboration of the original authors. Further observationsare added about rare and interesting taxa treated in Hoffmann & Walter.En la última edición de su libro sobre Cactáceas en Chile, A. E. Hoffmann & H. E. Walter (2004), además de un errorortográfico, publicaron incorrectamente algunas novedades taxonómicas del género Eriosyce, tal como fue revisado yaumentado por Katterman (1994), lo que las hace inválidas. Estos se corrigen aquí con la cooperación de los autoresoriginales. Además se agregan otras observaciones acerca de algunos raros e interesantes taxas tratados por Hoffmann &Walter

A new Viola (Violaceae) from the Argentinian Andes

Viola beati, a hitherto unknown species of V. sect. Andinium (Violaceae) is described and illustrated. It is an inconspicuous, diminutive, perennial forb currently known from only one locality in NW Argentina. We draw attention to its morphology, ecology, rarity and endemism. The differences between V. beati and its apparently only close relative, V. singularis J. M. Watson & A. R. Flores, are defined

Generalized Affine Coherent States: A Natural Framework for Quantization of Metric-like Variables

Affine variables, which have the virtue of preserving the positive-definite character of matrix-like objects, have been suggested as replacements for the canonical variables of standard quantization schemes, especially in the context of quantum gravity. We develop the kinematics of such variables, discussing suitable coherent states, their associated resolution of unity, polarizations, and finally the realization of the coherent-state overlap function in terms of suitable path-integral formulations.Comment: 17 pages, LaTeX, no figure

Investigating CXOU J163802.6-471358: a new pulsar wind nebula in the Norma region?

We present the first analysis of the extended source CXOU J163802.6--471358, which was discovered serendipitously during the {\em Chandra} X-ray survey of the Norma region of the Galactic spiral arms. The X-ray source exhibits a cometary appearance with a point source and an extended tail region. The complete source spectrum is fitted well with an absorbed power law model and jointly fitting the {\em Chandra} spectrum of the full source with one obtained from an archived {\em XMM-Newton} observation results in best fit parameters $N_{\rm H}$ $=1.5^{+0.7}_{-0.5}\times10^{23} \text{cm}{^{-2}}$ and $\Gamma=1.1^{+0.7}_{-0.6}$ (90$$ confidence uncertainties). The unabsorbed luminosity of the full source is then $L_X\sim 4.8\times10^{33}d_{10}^2$ergs s$^{-1}$ with $d_{10}=d/10$kpc, where a distance of 10 kpc is a lower bound inferred from the large column density. The radio counterpart found for the source using data from the Molonglo Galactic Plane Survey epoch-2 (MGPS-2) shows an elongated tail offset from the X-ray emission. No infrared counterpart was found. The results are consistent with the source being a previously unknown pulsar driving a bow shock through the ambient medium

The Physical Characteristics of the Small-Scale Interstellar Structure towards Mu Crucis

We present HST/GHRS echelle observations of multiple interstellar lines of CI, MgI, CrII, and ZnII towards both stars in the mu Cru binary system. Despite large differences in the profiles of the neutral species, no significant variations between the stars are seen in the CrII and ZnII line profiles. In particular, the ZnII absorption observed at -8.6 km/sec towards mu Cru is constant despite greatly enhanced columns of the neutral species at this velocity towards mu^1 Cru. An analysis of the fine-structure excitation of CI in this cloud implies that the density is n_H < 250 cm^{-3}. From the lack of variation in the (optical) NaI D2 line profiles towards mu^1 and mu^2 Cru in spectra taken 21 months apart, we can place a lower limit to the size of the structures of ~10 AU. These results are discussed in the context of recent radio and optical studies of apparently pervasive high density small-scale interstellar structure.Comment: 10 pages, 2 figures, to appear in the Astrophysical Journal (Letters