308 research outputs found

    Black South African short fiction in English since 1976

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    African Studies Seminar series. Paper presented 18 August 1986The students' uprising of 1976 hardly features in stories by black South African writers. In this respect, the short story is noticeably different from novels, plays and poems by black writers in which these events are often given central place. Short fiction, one should indicate, has been a predominant genre in the black community since the 1950's. What one sees happening after 1976 is not so much, a new direction for this genre, but a flowering of new works in the form. That is, the major collections of black short fiction since 1975 have not offered any major break with foregoing traditions in the form, as most certainly seems the case with the novel, but have continued the exploration of themes and concerns central to earlier collections of black short stories: what is different is the emefeence of new writers in the form. In this essay, I shall examine the key elements of black South African short fiction in English since 1976, touching upon connections not only with earlier collections of black short fiction but also with short fiction by white South African writers

    South African short fiction in English and Afrikaans since 1948.

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    Prevailing critical practice tends to view South African literature as comprising a number of writing communities in the country whose works and concerns have little to do with each other. Hence literary works in English and in Afrikaans, by black and by white South African writers are rarely considered in relation to one another. Literary criticism in South Africa has, in other words, proceeded along much the same lines as the political determinations of the country, dividing the literature into distinct racial and linguistic camps. While I have chosen to consider South African short fiction with reference to different major writing communities in the country, an underlying principle of this study is the essential unity of South African literature. Works in different languages and by writers of different social groups are seen as comprising a single national literature. Consequently I have followed the practice throughout of frequently drawing comparisons between stories by writers in English and in Afrikaans, by black and by white writers. One sees as the study develops how works by writers in all of the communities are closely related to one another. Black and white South African writers share a host of common concerns in their works. The short story has been chosen as the genre for consideration in this work because it is a predominant literary form in all of the major South African communities. It has been at the cutting edge of developments in South African prose fiction since the 194-0's. The short story sharply illustrates not only historical and social changes in the country but also changing patterns within the writing communities. The historical context of this study is that of the short period of ascendency of Afrikaner nationalism during the 1950's and 1960's and the indications of this movement's gradual disintegration and collapse during the 1970's and 1980's. This is seen against the emergence of African nationalism as the most forceful adversary of white racism in South Africa. The section on the white short fiction in English takes as one of its key points of examination the notable range and diversity in its works; this is directly linked with the fact that this community is at a remove from the central historical clash between Afrikaner and African nationalisms. The short fiction of Afrikaners is considered in two phases, that of the 1950's and 1960's, and then from the 1970's on. In the first phase the writers were striving to modernize their prose tradition and to a great extent abandoned pressing local issues for an involvement in the fashionable trends and concerns of contemporary European and American writers. By the 1970's, however, Afrikaans writing returns to share the concerns of English South African writers about the ravages of apartheid in the region. Black short fiction of this era is viewed as dealing with a central tension in the black community: namely, the threat of violence against traditional values of communalism. The study concludes with an appraisal of the literature of apartheid assessing its place within African and international literary traditions. The principal writers discussed in this study are: Hennie Aucamp, Chris Barnard, H.C. Bosman, M.C. Botha, Breyten Breytenbach, Jack Cope, Achmat Dangor, Abraham De Vries, Ahmed Essop, Nadine Gordimer, Henriette Grove, P.J. Haasbroek, Bessie Head, Christopher Hope, Dan Jacobson, Elsa Joubert, Alex La Guma, E.M. Macphail, Mtutuzeli Matshoba, James Matthews, John Miles, Casey Motsisi, Es'kia Mphahlele, Mbulelo Mzamane, Njabulo Ndebele, Welma Odendaal, Alan Paton, Jan Rabie, Richard Rive, Sheila Roberts, Barney Simon, Can Themba, and Peter Wilhelm

    Spectropolarimetric Evidence for Radiatively Inefficient Accretion in an Optically Dull Active Galaxy

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    We present Subaru/FOCAS spectropolarimetry of two active galaxies in the Cosmic Evolution Survey. These objects were selected to be optically dull, with the bright X-ray emission of an AGN but missing optical emission lines in our previous spectroscopy. Our new observations show that one target has very weak emission lines consistent with an optically dull AGN, while the other object has strong emission lines typical of a host-diluted Type 2 Seyfert galaxy. In neither source do we observe polarized emission lines, with 3-sigma upper limits of P_BLR < 2%. This means that the missing broad emission lines (and weaker narrow emission lines) are not due to simple anisotropic obscuration, e.g., by the canonical AGN torus. The weak-lined optically dull AGN exhibits a blue polarized continuum with P = 0.78 +/- 0.07% at 4400 A < lambda_rest < 7200 A (P = 1.37 +/- 0.16% at 4400 A < lambda_rest < 5050 A). The wavelength dependence of this polarized flux is similar to that of an unobscured AGN continuum and represents the intrinsic AGN emission, either as synchrotron emission or the outer part of an accretion disk reflected by a clumpy dust scatterer. Because this intrinsic AGN emission lacks emission lines, this source is likely to have a radiatively inefficient accretion flow.Comment: Accepted to ApJ. 6 pages, 2 figure

    Evolution of the Quasar Luminosity Function Over 3 < z < 5 in the COSMOS Survey Field

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    We investigate the high-redshift quasar luminosity function (QLF) down to an apparent magnitude of I(AB) = 25 in the Cosmic Evolution Survey (COSMOS). Careful analysis of the extensive COSMOS photometry and imaging data allows us to identify and remove stellar and low-redshift contaminants, enabling a selection that is nearly complete for type-1 quasars at the redshifts of interest. We find 155 likely quasars at z > 3.1, 39 of which have prior spectroscopic confirmation. We present our sample in detail and use these confirmed and likely quasars to compute the rest-frame UV QLF in the redshift bins 3.1 < z < 3.5 and 3.5 < z < 5. The space density of faint quasars decreases by roughly a factor of four from z \sim 3.2 to z \sim 4, with faint-end slopes of {\beta} \sim -1.7 at both redshifts. The decline in space density of faint optical quasars at z > 3 is similar to what has been found for more luminous optical and X-ray quasars. We compare the rest-frame UV luminosity functions found here with the X-ray luminosity function at z > 3, and find that they evolve similarly between z \sim 3.2 and z \sim 4; however, the different normalizations imply that roughly 75% of X-ray bright active galactic nuclei (AGN) at z \sim 3 - 4 are optically obscured. This fraction is higher than found at lower redshift and may imply that the obscured, type-2 fraction continues to increase with redshift at least to z \sim 4. Finally, the implications of the results derived here for the contribution of quasars to cosmic reionization are discussed.Comment: Accepted for publication in ApJ. 17 pages, 14 figure

    Elevated Gestational IL-13 During Fetal Development Is Associated With Hyperactivity and Inattention in Eight-Year-Old Children

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    Maternal immune activation (MIA) during fetal development leads to behavioral and psychological disorders in the offspring. Concomitantly, insufficient supply of polyunsaturated fatty acids (PUFAs) is suspected to contribute to early neuronal maldevelopment due to the immune modulatory capabilities of PUFAs. However, human data are missing considering both of these aspects and their impact on children's behavioral outcomes. In line, this study aimed to elucidate the influence of gestational cytokines and PUFA-containing lipids during late pregnancy on behavioral sequelae in childhood, particularly focusing on an immune activation shaped by a history of maternal atopic diseases instead of a pathogen-mediated immune response. Based on the prospective mother-child cohort LINA we assessed the unstimulated blood cytokine profiles and concentrations of PUFA-containing lipids of 293 mothers at the 34th week of pregnancy. Maternal history of atopic diseases was obtained from questionnaires and behavior in eight-year-old children was assessed by the standardized Strength and Difficulties Questionnaires (SDQ) generating scores for hyperactivity/inattention, emotional symptoms, conduct problems, and peer relationship problems. Elevated IL-13 increased the risk for the child to show behavioral difficulties, in particular, hyperactive/inattentive behavior [adj. OR (95% CI): 2.47 (1.51-4.02), n = 255 vs. 38] at the age of eight years. Although the presence of maternal atopic dermatitis (AD) was associated with increased gestational IL-13 concentrations [adj. MR (95% CI): 1.17 (1.04-1.32)], no effect on children's behavioral difficulties was observed. However, a decrease in the PUFA containing lipid species PC aa C38:6 was not only associated with an increased gestational IL-13 concentration but also mediated the indirect effect of low PC aa C38:6 concentrations on children's abnormal behavior independent of maternal AD. We additionally assessed whether maternal IL-13 and PC aa C38:6 concentrations translate their effect by altering children's cord blood PC aa C38:6 and IL-13. While also the children's cord blood IL-13 was related to children's behavior, no effect of children's PC aa C38:6 was observed. This is the first study demonstrating that elevated gestational IL-13 increases the risk for children to develop behavioral difficulties. Analyses suggest that a reduced supply of gestational PC aa C38:6 contributes to elevated gestational IL-13 leading to behavioral sequelae in the offspring

    Massive Galaxies in COSMOS: Evolution of Black hole versus bulge mass but not versus total stellar mass over the last 9 Gyrs?

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    We constrain the ratio of black hole (BH) mass to total stellar mass of type-1 AGN in the COSMOS survey at 1<z<2. For 10 AGN at mean redshift z~1.4 with both HST/ACS and HST/NICMOS imaging data we are able to compute total stellar mass M_(*,total), based on restframe UV-to-optical host galaxy colors which constrain mass-to-light ratios. All objects have virial BH mass-estimates available from the COSMOS Magellan/IMACS and zCOSMOS surveys. We find zero difference between the M_BH--M_(*,total)-relation at z~1.4 and the M_BH--M_(*,bulge)-relation in the local Universe. Our interpretation is: (a) If our objects were purely bulge-dominated, the M_BH--M_(*,bulge)-relation has not evolved since z~1.4. However, (b) since we have evidence for substantial disk components, the bulges of massive galaxies (logM_(*,total)=11.1+-0.25 or logM_BH~8.3+-0.2) must have grown over the last 9 Gyrs predominantly by redistribution of disk- into bulge-mass. Since all necessary stellar mass exists in the galaxy at z=1.4, no star-formation or addition of external stellar material is required, only a redistribution e.g. induced by minor and major merging or through disk instabilities. Merging, in addition to redistributing mass in the galaxy, will add both BH and stellar/bulge mass, but does not change the overall final M_BH/M_(*,bulge) ratio. Since the overall cosmic stellar and BH mass buildup trace each other tightly over time, our scenario of bulge-formation in massive galaxies is independent of any strong BH-feedback and means that the mechanism coupling BH and bulge mass until the present is very indirect.Comment: Published in ApJL; 7 pages, 2 figures; updated to accepted version (methods changed, results unchanged

    Observational limits on type 1 active galactic nucleus rate in COSMOS

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    We present black hole masses and accretion rates for 182 Type 1 active galactic nuclei (AGNs) in COSMOS. We estimate masses using the scaling relations for the broad H β, Mg ii, and C iv emission lines in the redshift ranges 0.16 < z < 0.88, 1 < z < 2.4, and 2.7 < z < 4.9. We estimate the accretion rate using an Eddington ratio LI/L_(Edd) estimated from optical and X-ray data.We find that very few Type 1 AGNs accrete below LI/L_(Edd) ∼ 0.01, despite simulations of synthetic spectra which show that the survey is sensitive to such Type 1 AGNs. At lower accretion rates the broad-line region may become obscured, diluted, or nonexistent. We find evidence that Type 1 AGNs at higher accretion rates have higher optical luminosities, as more of their emission comes from the cool (optical) accretion disk with respect to shorter wavelengths. We measure a larger range in accretion rate than previous works, suggesting that COSMOS is more efficient at finding low accretion rate Type 1 AGNs. However, the measured range in accretion rate is still comparable to the intrinsic scatter from the scaling relations, suggesting that Type 1 AGNs accrete at a narrow range of Eddington ratio, with LI/L_(Edd) ∼ 0.1

    Magellan Spectroscopy of AGN Candidates in the COSMOS Field

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    We present spectroscopic redshifts for the first 466 X-ray and radio-selected AGN targets in the 2 deg^2 COSMOS field. Spectra were obtained with the IMACS instrument on the Magellan (Baade) telescope, using the nod-and-shuffle technique. We identify a variety of Type 1 and Type 2 AGN, as well as red galaxies with no emission lines. Our redshift yield is 72% down to i_AB=24, although the yield is >90% for i_AB<22. We expect the completeness to increase as the survey continues. When our survey is complete and additional redshifts from the zCOSMOS project are included, we anticipate ~1100 AGN with redshifts over the entire COSMOS field. Our redshift survey is consistent with an obscured AGN population that peaks at z~0.7, although further work is necessary to disentangle the selection effects.Comment: 19 pages, 14 figures. Accepted to ApJS special COSMOS issue. The full electronic version of Table 2 can be found at http://shaihulud.as.arizona.edu/~jtrump/tab2.tx

    The Nature of Optically Dull Active Galactic Nuclei in COSMOS

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    We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull AGNs in the COSMOS field. These objects exhibit the X-ray luminosity of an active galactic nucleus (AGN) but lack broad and narrow emission lines in their optical spectrum. We show that despite the lack of optical emission lines, most of these optically dull AGNs are not well-described by a typical passive red galaxy spectrum: instead they exhibit weak but significant blue emission like an unobscured AGN. Photometric observations over several years additionally show significant variability in the blue emission of four optically dull AGNs. The nature of the blue and infrared emission suggest that the optically inactive appearance of these AGNs cannot be caused by obscuration intrinsic to the AGNs. Instead, up to ~70% of optically dull AGNs are diluted by their hosts, with bright or simply edge-on hosts lying preferentially within the spectroscopic aperture. The remaining ~30% of optically dull AGNs have anomalously high f_x/f_o ratios and are intrinsically weak, not obscured, in the optical. These optically dull AGNs are best described as a weakly accreting AGN with a truncated accretion disk from a radiatively inefficient accretion flow.Comment: 12 pages, 10 figures. Accepted for publication in the Ap

    Observational Limits on Type 1 AGN Accretion Rate in COSMOS

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    We present black hole masses and accretion rates for 182 Type 1 AGN in COSMOS. We estimate masses using the scaling relations for the broad Hb, MgII, and CIV emission lines in the redshift ranges 0.16<z<0.88, 1<z<2.4, and 2.7<z<4.9. We estimate the accretion rate using an Eddington ratio L_I/L_Edd estimated from optical and X-ray data. We find that very few Type 1 AGN accrete below L_I/L_Edd ~ 0.01, despite simulations of synthetic spectra which show that the survey is sensitive to such Type 1 AGN. At lower accretion rates the BLR may become obscured, diluted or nonexistent. We find evidence that Type 1 AGN at higher accretion rates have higher optical luminosities, as more of their emission comes from the cool (optical) accretion disk with respect to shorter wavelengths. We measure a larger range in accretion rate than previous works, suggesting that COSMOS is more efficient at finding low accretion rate Type 1 AGN. However the measured range in accretion rate is still comparable to the intrinsic scatter from the scaling relations, suggesting that Type 1 AGN accrete at a narrow range of Eddington ratio, with L_I/L_Edd ~ 0.1.Comment: Accepted for pulication in ApJ. 7 pages, 5 figures, table 1 available on reques
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