The Size and Origin of Metal-enriched Regions in the Intergalactic Medium from Spectra of Binary Quasars

We present tomography of the circum-galactic metal distribution at redshift 1.7-4.5 derived from echellete spectroscopy of binary quasars. We find C IV systems at similar redshifts in paired sightlines more often than expected for sightline-independent redshifts. As the separation of the sightlines increases from 36 kpc to 907 kpc, the amplitude of this clustering decreases. At the largest separations, the C IV systems cluster similar to the Lyman-break galaxies studied by Adelberger et al. in 2005. The C IV systems are significantly less correlated than these galaxies, however, at separations less than R_1 0.42 ± 0.15 h^( –1) comoving Mpc. Measured in real space, i.e., transverse to the sightlines, this length scale is significantly smaller than the break scale estimated previously from the line-of-sight correlation function in redshift space by Scannapieco et al. in 2006. Using a simple model, we interpret the new real-space measurement as an indication of the typical physical size of enriched regions. We adopt this size for enriched regions and fit the redshift-space distortion in the line-of-sight correlation function. The fitted velocity kick is consistent with the peculiar velocity of galaxies as determined by the underlying mass distribution and places an upper limit on the average outflow (or inflow) speed of metals. The implied timescale for dispersing metals is larger than the typical stellar ages of Lyman-break galaxies, and we argue that enrichment by galaxies at z > 4.3 played a greater role in dispersing metals. To further constrain the growth of enriched regions, we discuss empirical constraints on the evolution of the C IV correlation function with cosmic time. This study demonstrates the potential of tomography for measuring the metal enrichment history of the circum-galactic medium

Small-scale eruptive filaments on the quiet sun

A study of a little known class of eruptive events on the quiet sun was conducted. All of 61 small-scale eruptive filamentary structures were identified in a systematic survey of 32 days of H alpha time-lapse films of the quiet sun acquired at Big Bear Solar Observatory. When fully developed, these structures have an average length of 15 arc seconds before eruption. They appear to be the small-scale analog of large-scale eruptive filaments observed against the disk. At the observed rate of 1.9 small-scale eruptive features per field of view per average 7.0 hour day, the rate of occurence of these events on the sun were estimated to be greater than 600 per 24 hour day.. The average duration of the eruptive phase was 26 minutes while the average lifetime from formation through eruption was 70 minutes. A majority of the small-scale filamentary sturctures were spatially related to cancelling magnetic features in line-of-sight photospheric magnetograms. Similar to large-scale filaments, the small-scale filamentary structures sometimes divided opposite polarity cancelling fragments but often had one or both ends terminating at a cancellation site. Their high numbers appear to reflect the much greater flux on the quiet sun. From their characteristics, evolution, and relationship to photospheric magnetic flux, it was concluded that the structures described are small-scale eruptive filaments and are a subset of all filaments

Reduction of primordial chaos by generic quantum effects

According to general relativity, the generic early-universe dynamics is chaotic. Various quantum-gravity effects have been suggested that may change this behavior in different ways. Here, it is shown how key mathematical properties of the classical dynamics can be extended to evolving quantum states using quasiclassical methods, making it possible to apply the established dynamical-systems approach to chaos even to quantum evolution. As a result, it is found that quantum fluctuations contribute to the reduction of the primordial chaos in early-universe models.Comment: 11 pages, 2 figures, accepted for publication as a letter in Physical Review

Generalized Wick's theorem for multiquasiparticle overlaps as a limit of Gaudin's theorem

We are able to rederive in a very simple way the standard generalized Wick's theorem for overlaps of mean field wave functions by using the extension of the statistical Wick's theorem (Gaudin's theorem) in the appropriate limits.Comment: 28 page

Transverse Sizes of CIV Absorption Systems Measured from Multiple QSO Sightlines

We present tomography of the circum-galactic metal distribution at redshift 1.7 to 4.5 derived from echellete spectroscopy of binary quasars. We find CIV systems at similar redshifts in paired sightlines more often than expected for sightline-independent redshifts. As the separation of the sightlines increases from 36 kpc to 907 kpc, the amplitude of this clustering decreases. At the largest separations, the CIV systems cluster similar to Lyman-break galaxies (Adelberger et al. 2005a). The CIV systems are significantly less correlated than these galaxies, however, at separations less than R_1 ~ 0.42 +/- 0.15 h-1 comoving Mpc. Measured in real space, i.e., transverse to the sightlines, this length scale is significantly smaller than the break scale estimated from the line-of-sight correlation function in redshift space (Scannapieco et al. 2006a). Using a simple model, we interpret the new real-space measurement as an indication of the typical physical size of enriched regions. We adopt this size for enriched regions and fit the redshift-space distortion in the line-of-sight correlation function. The fitted velocity kick is consistent with the peculiar velocity of galaxies as determined by the underlying mass distribution and places an upper limit on the outflow (or inflow) speed of metals. The implied time scale for dispersing metals is larger than the typical stellar ages of Lyman-break galaxies (Shapley et al. 2001), and we argue that enrichment by galaxies at z > 4.3 played a greater role in dispersing metals. To further constrain the growth of enriched regions, we discuss empirical constraints on the evolution of the CIV correlation function with cosmic time. This study demonstrates the potential of tomography for measuring the metal enrichment history of the circum-galactic medium.Comment: 22 pages, 15 figures, 1 tabl

The Build-up to Eruptive Solar Events Viewed as the Development of Chiral Systems

Copyright © Copyright 2012 Astronomical Society of the PacificWhen we examine the chirality or observed handedness of the chromospheric and coronal structures involved in the long-term build-up to eruptive events, we find that they evolve in very specific ways to form two and only two sets of large-scale chiral systems. Each system contains spatially separated components with both signs of chirality, the upper portion having negative (positive) chirality and the lower part possessing positive (negative) chirality. The components within a system are a filament channel (represented partially by sets of chromospheric fibrils), a filament (if present), a filament cavity, sometimes a sigmoid, and always an overlying arcade of coronal loops. When we view these components as parts of large-scale chiral systems, we more clearly see that it is not the individual components of chiral systems that erupt but rather it is the approximate upper parts of an entire evolving chiral system that erupts. We illustrate the typical pattern of build-up to eruptive solar events first without and then including the chirality in each stage of the build-up. We argue that a complete chiral system has one sign of handedness above the filament spine and the opposite handedness in the barbs and filament channel below the filament spine. If the spine has handedness, the observations favor its having the handedness of the filament cavity and coronal loops above. As the separate components of a chiral system form, we show that the system appears to maintain a balance of right-handed and left-handed features, thus preserving an initial near-zero net helicity. Each individual chiral system may produce many successive eruptive events above a single filament channel.NSFNASANational Solar Observatory (NSO)AURA Inc., under cooperative agreement with the National Science Foundation (NSF).European Union Seventh Framework Programme (FP7/2007-2013) - COronal Mass Ejections and Solar Energetic Particles (COMESEP) projec