How Cosmic Background Correlations at Large Angles Relate to Mass Autocorrelations in Space

The Sachs-Wolfe effect is known to produce large angular scale fluctuations in the Cosmic Microwave Background Radiation (CMBR) due to gravitational potential fluctuations. We show how the angular correlation function of the CMBR can be expressed explicitly in terms of the mass autocorrelation function $\xi (r)$ in the Universe. We derive analytic expressions for the angular correlation function and its multipole moments in terms of integrals over $\xi (r)$ or its second moment, $J_3 (r)$, which does not need to satisfy the sort of integral constraint that $\xi (r)$ must. We derive similar expressions for bulk flow velocity in terms of $\xi$ and $J_3$. One interesting result that emerges directly from this analysis is that, for angles $\theta$, there is a substantial contribution to the correlation function from a wide range of distance $r$ and that the radial shape of this contribution does not vary greatly with angle.Comment: 9 pages in Plain TeX and 6 figures appended in 9 pages of uuencoded PostScript. Lick Preprint Number 1

Wounded Women, Varied Voice

Daphne du Maurier and Sylvia Plath both use voice as a tool in their respective pieces, “La Sainte-Vierge” and “Lesbos.” Through the implementation of varied voices, these women convey female interiors. Du Maurier’s use of a third-person narrative voice in her short story “La Sainte-Vierge” allows her to comment on the lives of the main characters through the eyes of an outsider. Du Maurier’s outsider reveals a naïve and delusional housewife, unhealthy in her denial within a failing relationship. Contrasting with du Maurier’s Marie is Plath’s first-person voice of a scorned, dissatisfied housewife in her poem, “Lesbos.” Plath’s use of the first-person voice is central to this poem’s effectiveness, allowing for an emotional reading of the thoughts of a bitter woman. Although the reaction of the wronged woman differs, both pieces powerfully employ voice to illustrate the effects of a failing relationship

Feasibility of Seismic Monitoring to Identify Avalanche Activity: Snoqualmie Pass, WA

Avalanches across the Interstate-90 corridor over Snoqualmie Pass, in Washington State, are a concern for winter travelers and backcountry recreation. The temporary closure of the interstate for avalanche mitigation work also affects commerce by delaying transportation of merchandise. The study of seismic signals associated with snow avalanches could allow for greater understanding of avalanche properties, while remote sensing of avalanche activity could help established avalanche control programs and regional avalanche centers with forecasting and mitigation efforts. Two seismic stations were installed near the Alpental ski area on Snoqualmie Pass and recorded seismic activity throughout the winters of 2009-2010 and 2010-2011. During the winter of 2010-2011, two avalanches were successfully recorded, one artificially released with explosives and one naturally during a rain on snow event. These results show that it is possible to record avalanche activity over the traffic noise of the interstate and that avalanche activity can be distinguished from other seismic sources. Similarities in the seismic signals with previous research show distinct characteristics associated with avalanches, however, no further conclusions on the seismic characteristics unique to this avalanche path can be made with such a small sample size; more research is necessary

Studying Evolution of the Galactic Potential and Halo Streamers with Future Astrometric Satellites

Future astrometric satellites, such as SIM (NASA's Space Interferometric Mission) and GAIA (ESA's Global Astrometric Interferometer for Astrophysics), hold the promise of mapping out the detailed phase space structure of the Galactic halo by providing unprecedented annual proper motion and parallax of $1-10\mu$as astrometric accuracy. Here we show that proper motions of hundred or so giant branch stars in a tidal debris torn from a small satellite (a $10^{5-7}L_\odot$ Galactic dwarf galaxy or globular cluster) in the halo is sensitive to the current Galactic potential and its past evolution. We follow the evolution of a cold (velocity dispersion of 10 km/s) stream on a nearby (between 8-50 kpc) polar orbit in a variety of histories of the potential of the Galaxy, and observe the bright ($V<18$mag) members of the debris tail with GAIA accuracy. We simulate effects due to the growing or flipping of the Galactic disk over the past 4 Gyrs or the perturbation from a massive accreted lump such as the progenitor of the Magellanic Clouds. We study various factors influencing our ability to identify streams, including contamination from field stars, accuracy of radial velocity and distance data and evolution and non-axial symmetry of the potential. Our simulations suggest that nearby, cold streams could be detected with GAIA if these cousins of the Sagittarius stream exist. Results of Johnston, Zhao, Spergel & Hernquist (1999) and Helmi, Zhao & de Zeeuw (1999) for static Galactic potentials are likely to be largely generalizable to moderately time-evolving potentials. SIM and GAIA measurements of debris stars might be used to probe both Galactic structure and Galactic history.Comment: 13 pages including 8 ps figures, to appear in The Galactic Halo: Bright Stars and Dark Matter, proceedings of the Third Stromlo Symposium, eds. B.Gibson, T.Axelrod, M.Putman (ASP Conference Series