We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets... Show moreWe present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 {$μ$}m Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = 0.''35, we find scattered light as close as 0.''1 (20-28 AU) from the star, with no visible cavity at H, K', or K$_s$ . We find two small-scaled spiral structures that asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h ~{} 0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5$^{+3}$ $_{- 4}$ M$_J$ , in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L' and angular differential imaging with Locally Optimized Combination of Images at K' and K$_s$ , we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0.''5. We reach 5{$σ$} contrasts limiting companions to planetary masses, 3-4 M$_J$ at 1.''0 and 2 M$_J$ at 1.''55, using the COND models. Collectively, these data strengthen the case for MWC 758 already being a young planetary system. Show less
Grady, C.; Muto, T.; Hashimoto, J.; Fukagawa, M.; Currie, T.; Biller, B.; ... ; Tamura, M. 2013
We present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and... Show moreWe present the first near-IR scattered light detection of the transitional disk associated with the Herbig Ae star MWC 758 using data obtained as part of the Strategic Exploration of Exoplanets and Disks with Subaru, and 1.1 {$μ$}m Hubble Space Telescope/NICMOS data. While submillimeter studies suggested there is a dust-depleted cavity with r = 0.''35, we find scattered light as close as 0.''1 (20-28 AU) from the star, with no visible cavity at H, K', or K$_s$ . We find two small-scaled spiral structures that asymmetrically shadow the outer disk. We model one of the spirals using spiral density wave theory, and derive a disk aspect ratio of h ~{} 0.18, indicating a dynamically warm disk. If the spiral pattern is excited by a perturber, we estimate its mass to be 5$^{+3}$ $_{- 4}$ M$_J$ , in the range where planet filtration models predict accretion continuing onto the star. Using a combination of non-redundant aperture masking data at L' and angular differential imaging with Locally Optimized Combination of Images at K' and K$_s$ , we exclude stellar or massive brown dwarf companions within 300 mas of the Herbig Ae star, and all but planetary mass companions exterior to 0.''5. We reach 5{$σ$} contrasts limiting companions to planetary masses, 3-4 M$_J$ at 1.''0 and 2 M$_J$ at 1.''55, using the COND models. Collectively, these data strengthen the case for MWC 758 already being a young planetary system. Show less
On 15 December 2006 Marloes Janson (Zentrum Moderner Orient, Berlin) and Dorothea Schulz (Indiana University) convened a workshop titled “Piety, Responsibility, Subjectivity: Reconfigurations of... Show moreOn 15 December 2006 Marloes Janson (Zentrum Moderner Orient, Berlin) and Dorothea Schulz (Indiana University) convened a workshop titled “Piety, Responsibility, Subjectivity: Reconfigurations of the Moral Economy of Gender Relations in Contemporary Muslim Africa” at the Snoeck Hurgronje Huis, Leiden. The workshop and the subsequent public event were sponsored by ISIM, in cooperation with the Knowledge Centre Religion and Development and ZemZem, Journal for the Middle East, North Africa, and Islam. Show less
Over the years, the Tablighi Jamaat has expanded into what is probably indeed the largest Islamic movement of contemporary times. Despite its magnitude, its impact in sub-Saharan Africa has been... Show moreOver the years, the Tablighi Jamaat has expanded into what is probably indeed the largest Islamic movement of contemporary times. Despite its magnitude, its impact in sub-Saharan Africa has been largely neglected. This article, based on ethnographic field research, focuses on the Jamaat in The Gambia (West Africa) where particularly youth convert to Tablighi ideology, in what could be seen as a form of rebellion against the authority of their elders. In the process, established religious and social values are redefined. Show less
Gambian griottes, or female bards, are in a serious predicament. Islamic ethics prescribe that women should behave in a modest way, while conversely the griottes' very profession implies that they... Show moreGambian griottes, or female bards, are in a serious predicament. Islamic ethics prescribe that women should behave in a modest way, while conversely the griottes' very profession implies that they stand out by their behaviour and the way they dress. How do these women reconcile their identity as female performers with Islamic values? The Gambia is an interesting setting in which to explore this question because of its long history with Islam. There was even talk that President Jammeh wanted to impose the sharica in this small West African country. Show less
