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

Space, power and sexuality: transgressive and transformative possibilities at the interstices of spatial boundaries

The themed section consists of articles that explore the relationship between power and space in relation to gender and sexuality by looking at processes of transgression, subversion or expansion of normative spatial practices and narratives. Using a theoretical framework that draws out power and space within a more specific context of feminist and queer literature, the articles explore the possibility to transgress, subvert or expand norms at the interstices of spatial boundaries beyond traditional binaries and hierarchies. Collectively, the articles call for a continued theoretical and methodological focus into the importance of looking at everyday sites of struggles and resistance in the crevasses, the liminal zones of space. The transgression of spatialized norms of sexuality and gender present a transformative potential that should be recognized for its political significance but, we argue, with caution as heteronormative and heteropatriarchal norms too often remain de rigueur in a neoliberal context

Immoral geographies and Soho's sex shops: exploring spaces of sexual diversity in London

London's Soho, situated in the urban heart of the city has long been understood as both a cosmopolitan and diverse space where transgression and deviance, particularly in relation to the sex industry and sexual commerce, are constitutive of this area. Drawing on three years of ethnographic fieldwork, we add to some of the existing debates on sexual spaces in Soho by documenting the changes to the social/sexual landscape of sex shops in this area, and look to geographers interested in the spatial politics of gender and sexuality to understand the importance of this particular place. Looking at two particular sex shops in Soho, we argue that the spatial practices in this very specific part of the city encourage a disruption of traditional hierarchies that often govern gender and sexed practices, and invite women, LGBTQ and kink communities to inhabit more inclusive spaces of sexual citizenship

Sanitising the city: exploring hegemonic gentrification in London's Soho

This article will explore the gentrification of Soho, reflecting on ethnographic research undertaken in the area over the past fifteen months, to argue that the recent social, political, and economic changes in Soho must be understood in relation to private, marketized and globalized neoliberal capitalist forces. We argue that the changes to the area result in a heavily-weighted form of gentrification that works to actively and knowingly sanitize the city, removing 'undesirable' people and venues from the area. As such, we propose to define this process as 'hegemonic gentrification', and distinguish this from other forms of gentrification in order to understand the different processes that underpin these specific changes, and more broadly, it allows us to problematize these changes as regards to the 'right to the city', and to expand current understandings in a way that allows for a more nuanced analysis of urban gentrification and its impacts within neolibreral capitalism

Optical Spectroscopy of the IRAS 1-Jy Sample of Ultraluminous Infrared Galaxies

This paper discusses the optical spectroscopic properties of the IRAS 1-Jy sample of ultraluminous infrared galaxies (ULIGs). One hundred and eight of the 118 1-Jy ULIGs have been observed at dlambda = 8.3 AA resolution over the wavelength range ~4500 A -- 8900 A. These data are combined with large, previously published sets of optical spectroscopic data of lower luminosity infrared galaxies to look for systematic trends with infrared luminosity over the luminosity range L_ir ~ 10^{10.5}-10^{13} L_sun. As found in previous studies, the fraction of Seyfert galaxies among luminous infrared galaxies increases abruptly above L_ir ~ 10^{12.3} L_sun --- about 50% of the galaxies with L_ir > 10^{12.3} L_sun present Seyfert characteristics. Many of the optical and infrared spectroscopic properties of the Seyfert galaxies are consistent with the presence of a genuine active galactic nucleus (AGN). About 30% of these galaxies are Seyfert 1s with broad-line regions similar to those of optical quasars. The percentage of Seyfert 1 ULIGs increases with infrared luminosity, contrary to the predictions of the standard unification model for Seyfert galaxies. Comparisons of the broad-line luminosities of optical and obscured Seyfert 1 ULIGs with those of optically selected quasars of comparable bolometric luminosity suggest that the dominant energy source in most of these ULIGs is the same as in optical quasars, namely mass accretion onto a supermassive black hole, rather than a starburst. These results are consistent with recently published ISO, ASCA, and VLBI data. (abridged)Comment: Text and 23 figures (45 pages), Tables 1 - 6 (16 pages