The Peculiar Velocities of Local Type Ia Supernovae and their Impact on Cosmology

We quantify the effect of supernova Type Ia peculiar velocities on the derivation of cosmological parameters. The published distant and local Ia SNe used for the Supernova Legacy Survey first-year cosmology report form the sample for this study. While previous work has assumed that the local SNe are at rest in the CMB frame (the No Flow assumption), we test this assumption by applying peculiar velocity corrections to the local SNe using three different flow models. The models are based on the IRAS PSCz galaxy redshift survey, have varying beta = Omega_m^0.6/b, and reproduce the Local Group motion in the CMB frame. These datasets are then fit for w, Omega_m, and Omega_Lambda using flatness or LambdaCDM and a BAO prior. The chi^2 statistic is used to examine the effect of the velocity corrections on the quality of the fits. The most favored model is the beta=0.5 model, which produces a fit significantly better than the No Flow assumption, consistent with previous peculiar velocity studies. By comparing the No Flow assumption with the favored models we derive the largest potential systematic error in w caused by ignoring peculiar velocities to be Delta w = +0.04. For Omega_Lambda, the potential error is Delta Omega_Lambda = -0.04 and for Omega_m, the potential error is Delta Omega_m < +0.01. The favored flow model (beta=0.5) produces the following cosmological parameters: w = -1.08 (+0.09,-0.08), Omega_m = 0.27 (+0.02,-0.02) assuming a flat cosmology, and Omega_Lambda = 0.80 (+0.08,-0.07) and Omega_m = 0.27 (+0.02,-0.02) for a w = -1 (LambdaCDM) cosmology.Comment: 4 pages, 2 figures, 1 table, accepted for publication in ApJ Letter

A New Brown Dwarf Desert? A Scarcity of Wide Ultracool Binaries

We present the results of a deep-imaging search for wide companions to low-mass stars and brown dwarfs using NSFCam on IRTF. We searched a sample of 132 M7-L8 dwarfs to magnitude limits of $J \sim 20.5$ and $K \sim 18.5$, corresponding to secondary-primary mass ratios of $\sim 0.5$. No companions were found with separations between 2{\arcsec} to 31{\arcsec} ($\sim$40 AU to $\sim$1000 AU). This null result implies a wide companion frequency below 2.3% at the 95% confidence level within the sensitivity limits of the survey. Preliminary modeling efforts indicate that we could have detected 85% of companions more massive than $0.05 M_{\odot}$ and 50% above $0.03 M_{\odot}$.Comment: 27 pages, 8 figures, 3 tables: accepted to the Astronomical Journa

“Superfluous Men” : the graveyard politics of The Duchess of Malfi

This essay reads Webster’s tragedy in the context of the untimely death of King James’s eldest son, Henry, Prince of Wales, and of his father’s failure to honour the Protestant hero with a suitable memorial. Centring its argument on the Echo scene (V.iii), it seeks to show how the play’s recurrent graveyard imagery contributes to its dissident politics. Setting the bourgeois virtues imagined as “integrity of life” against the pretensions of inherited rank, this “citizen tragedy” redefines the idea of “greatness”, thereby becoming Webster’s most significant monument to the values for which Prince Henry had, in the minds of his admirers, come to stand.Cet article revisite la tragédie de Webster à la lumière du contexte de la mort prématurée d’Henry, prince de Galles, fils aîné de Jacques Ier, et de l’incapacité du roi à faire construire un mémorial en l’honneur de celui qui fut considéré comme un héros protestant. Se fondant principalement sur la scène de l’Écho (V.iii), il vise à montrer comment l’imagerie du cimetière, récurrente dans la pièce, participe de la vision politique dissidente qu’elle développe. Cette “tragédie de la Cité”, dénomination qui parodie la “comédie de la Cité”, oppose les vertus bourgeoises garantes d’une vie intègre aux privilèges acquis. Elle redéfinit l’idée de “grandeur”, devenant ainsi le monument le plus significatif de Webster en hommage aux valeurs qu’incarnait le prince Henry dans l’esprit de ses admirateurs

Reviews

The following publications have been reviewed by the mentioned authors;The Art of the Engineer by Ken Baynes and Francis Pugh, reviewed by Michael SayerVictorian Crafts Revived by Anne Hulbert, reviewed by Andor GommeA Potter's Mexico by Irwin and Emily Whittaker, reviewed by Michael PaffardPainting Without a Brush by Roy Sparkes, reviewed by Edward PhelpsMaking Wooden Toys by Roger Polley, reviewed by Bob NeillMetalwork Theory by R. A. Mold, reviewed by Leslie Deem