Confrontation of MOND with the rotation curves of early-type disc galaxies

We extend the MOND analysis to a sample of 17 high surface brightness, early-type disc galaxies with rotation curves derived from a combination of 21cm HI line observations and optical spectroscopic data. A number of these galaxies have asymptotic rotation velocities between 250 and 350 km/s making them among the most massive systems (in terms of baryonic mass) considered in the context of MOND. We find that the general MOND prediction for such galaxies -- a rotation curve which gradually declines to the asymptotic value -- is confirmed, and in most cases the MOND rotation curve, determined from the mean radial light and gas distribution, agrees in detail with the observed rotation curve. In the few cases where MOND appears not to work well, the discrepancies can generally be understood in terms of various observational errors -- such as incorrect orientation angles and/or distances -- or of unmodelled physical effects -- such as non-circular motions. The implied mass-to-light ratios for the stellar disc and bulge constrain the MOND interpolating function; the form recently suggested by Zhao & Famaey (2005) yields more sensible values than the one traditionally used in MOND determinations of galaxy rotation curves.Comment: 9 pages, 2 figures, submitted MNRA

Wind-tunnel Tests of a Hall High-life Wing

Wind-tunnel tests have been made to find the lift, drag, and center-of-pressure characteristics of a Hall high-lift wing model. The Hall wing is essentially a split-flap airfoil with an internal air passage. Air enters the passage through an opening in the lower surface somewhat back of and parallel to the leading edge, and flows out through an opening made by deflecting the rear portion of the under surface downward as a flap. For ordinary flight conditions the front opening and the rear flap can be closed, providing in effect a conventional airfoil (the Clark Y in this case). The tests were made with various flap settings and with the entrance to the passage both open and closed. The highest lift coefficient found, C(sub L) = 2.08, was obtained with the passage closed

Major Galaxy Mergers and the Growth of Supermassive Black Holes in Quasars

Despite observed strong correlations between central supermassive black holes (SMBHs) and star-formation in galactic nuclei, uncertainties exist in our understanding of their coupling. We present observations of the ratio of heavily-obscured to unobscured quasars as a function of cosmic epoch up to z~3, and show that a simple physical model describing mergers of massive, gas-rich galaxies matches these observations. In the context of this model, every obscured and unobscured quasar represent two distinct phases that result from a massive galaxy merger event. Much of the mass growth of the SMBH occurs during the heavily-obscured phase. These observations provide additional evidence for a causal link between gas-rich galaxy mergers, accretion onto the nuclear SMBH and coeval star formation.Comment: Accepted for publication in Science. Published by Science Express on March 25th. 17 pages, 5 figures, including supplemental online materia

Verifiable and Non-Verifiable Anonymous Mechanisms for Regulating a Polluting Monopolist

Optimal regulation of a polluting natural monopolist must correct for both external damages and market power to achieve a social optimum. Existing non-Bayesian regulatory methods require knowledge of the demand function, while Bayesian schemes require knowledge of the underlying cost distribution. We introduce mechanisms adapted to use less information. Our Price-based Subsidy (PS) mechanisms give the firm a transfer that matches or approximates the incremental surplus generated each period. The regulator need not observe the abatement activity or know the demand, cost, or damage functions of the firm. All of the mechanisms induce the firm to price at marginal social cost, either immediately or asymptotically.surplus subsidy schemes, polluting monopolist, verifiable regulatory mechanisms

Porn by any other name: women’s consumption of public sex performances in Amsterdam

Women’s engagement with pornography has been a divisive debate within feminism. Much of the traditional debates have focused on pornography’s sexual and visual content, suggesting that women are objectified in pornographic representations (Dworkin, 1979), problematizing the consumption of porn and assuming that pornography is created by men for men (c.f. Gunter, 2002). There is an emerging literature, however, that seeks to explore the ways in which women consume and understand pornographic materials (Loach, 1992; Senn, 1993; Shaw, 1999; Eck, 2003; Ciclitira, 2004; Attwood, 2005; Smith, 2007), which seem to suggest that women’s responses to porn are complex, and cannot be easily categorized. This paper intends to further these emerging discussions by focusing on an under-researched area – public sex performance. Little has been written on public sex performance (c.f. Manderson, 1992; Delany, 1999; Sanders, 2010), and much less on women’s engagements with these types of venues. This paper will draw on ethnographic research conducted in Amsterdam, exploring the ways in which women tourists engage with public sex performances, drawing comparisons between these types of shows and other types of pornographic materials. Empirical data collected in Amsterdam, focusing on women’s visual consumption of public sex performances at a well-known tourist sexual theatres that features live sex (including vaginal penetrative sex and oral sexual encounters for/by men/women, as well as masturbation and other highly sexualized acts), suggests that sex shows are positioned as legitimate sexual entertainment for men, women, and couples, and that a wide range of tourist women from different backgrounds visit these shows in substantial numbers. By attempting to unpick the ways in which women visually consume public sex performances, and thinking about this in relation to broader discussions around pornography and the literature around women’s consumption practices, this paper will argue that many of the current understandings of pornography consumption as an androcentric activity fail to recognize women as active sexual, visual agents. Women’s engagement with sex shows in Amsterdam complicates the various ways in which visual consumption of pornography might occur, and opens up questions about the social and gendered practices of watching sex

Alaska Coastal Community Youth and the Future

The Alaska Sea Grant College Program. Project No. R/72-02.Executive Summary / Introduction / Background to the Research / Methods / Findings / Discussion and Policy Recommendations / Products from the Research / References Cited / Appendix A. Focus Group Protocol (High School) / Appendix B. Focus Group Protocol (12-20 year olds) / Appendix C. Focus Group Questionnaire / Appendix D. Occupational Rating Worksheet / Appendix E. Consent/Assent For

Searching for the missing iron in the core of the Centaurus cluster

We re-analyse a combined 198 ks Chandra observation of NGC4696, the brightest galaxy of the Centaurus cluster. We extract temperature and metallicity profiles from the data, and we confirm the presence of a sharp drop in iron abundance, from ~1.8 Zsolar to ~0.4 Zsolar, within the central 5 kpc of the cluster. We estimate that this abundance drop corresponds to a total "missing" iron mass of 1.4e06 Msolar. We propose that part of this missing iron is locked up in cool (~19 K) far-IR emitting dust, as found by Spitzer and Herschel observations. This can occur if the iron injected by stellar mass loss in the central region is in grains, which remain in that form as the injected dusty cold gas mixes and joins the cold dusty filamentary nebula observed within the same region. The bubbling feedback process observed in the cluster core then drags filaments outward and dumps them at 10-20 kpc radius, where the metallicity is high.Comment: 8 pages, accepted for publication in MNRA