Of Moice and Men: The Evolution of Male-led Sound Change

Some of the most prominent findings regarding the documentation of linguistic change and how social and linguistic factors affect change as it moves through a community have come from the project on Linguistic Change and Variation in Philadelphia (LCV) conducted in the 1970’s, and the analysis of these data (Labov 1994, 2001). This dissertation is a re-study of the Philadelphia speech community, focusing on the effects of sex on language change. The male-led change of the centralization of the nucleus of /ay/ before voiceless consonants (ay0) was selected as the focus of this dissertation. In addition to this variable, this dissertation investigates (aw) and (eyC) through a real time study using the methodology adopted by the LCV. A representative set of vowel tokens were measured and normalized for each subject, and these data were used in multiple regression analyses to identify changes in progress and possible social factors affecting the changes. In order to explore gender further, a 3-part Gender Index was created using sex, sexual orientation and childhood/adolescent socialization experiences. All three variables are still involved in change in apparent time, which is supported by real time analyses. The raising of (ay0) no longer shows a significant sex difference or social stratification. (aw) shows a reversal of the direction of the change in F2 as posited by the LCV, and the real time data confirm this analysis. (eyC) shows change in vowel height, rather than change in F2 as identified in the LCV data. Like (ay0), (eyC) does not show sex differentiation. While the Gender Index does not show significant effects predicting vowel production for any of these variables, sexual orientation does: lesbian women are leading the changes of (aw) and (eyC), while gay men show some resistance to these changes. A matched guise test shows that Philadelphians evaluate the linguistic behavior of women and men on different scales with respect to (ay0). This dissertation shows that language change can exist without sex differentiation, and that sexual orientation is a significant social factor in language change

Correcting the influence of an asymmetric line spread function in 2-degree Field spectrograph data

We investigate the role of asymmetries in the line spread function of the 2-degree field spectrograph and the variations in these asymmetries with the CCD, the plate, the time of observation and the fibre. A data-reduction pipeline is developed that takes these deformations into account for the calibration and cross-correlation of the spectra. We show that, using the emission lines of calibration lamp observations, we can fit the line spread function with the sum of two Gaussian functions representing the theoretical signal and a perturbation of the system. This model is then used to calibrate the spectra and generate templates by downgrading high resolution spectra. Thus, we can cross-correlate the observed spectra with templates degraded in the same way. Our reduction pipeline is tested on real observations and provides a significant improvement in the accuracy of the radial velocities obtained. In particular, the systematic errors that were as high as ~20 km/s when applying the AAO reduction package 2dfDR are now reduced to ~5 km/s. Even though the 2-degree Field spectrograph is to be decommissioned at the end of 2005, the analysis of archival data and previous studies could be improved by the reduction procedure we propose here.Comment: 9 pages, 9 figures, accepted to PASA, minor change

Gemini and Lowell observations of 67P/Churyumov−Gerasimenko during the <i>Rosetta</i> mission

We present observations of comet 67P/Churyumov−Gerasimenko acquired in support of the Rosetta mission. We obtained usable data on 68 nights from 2014 September until 2016 May, with data acquired regularly whenever the comet was observable. We collected an extensive set of near-IR J, H and Ks data throughout the apparition plus visible-light images in g', r', i' and z' when the comet was fainter. We also obtained broad-band R and narrow-band CN filter observations when the comet was brightest using telescopes at Lowell Observatory. The appearance was dominated by a central condensation and the tail until 2015 June. From 2015 August onwards, there were clear asymmetries in the coma, which enhancements revealed to be due to the presence of up to three features (i.e. jets). The features were similar in all broad-band filters; CN images did not show these features but were instead broadly enhanced in the southeastern hemisphere. Modelling using the parameters from Vincent et al. replicated the dust morphology reasonably well, indicating that the pole orientation and locations of active areas have been relatively unchanged over at least the last three apparitions. The dust production, as measured by A(0°)fρ peaked ∼30 d after perihelion and was consistent with predictions from previous apparitions. A(0°)fρ as a function of heliocentric distance was well fitted by a power law with slope −4.2 from 35 to 120 d post-perihelion. We detected photometric evidence of apparent outbursts on 2015 August 22 and 2015 September 19, although neither was discernible morphologically in this data set