Dust and ionized gas in active radio elliptical galaxies

The authors present broad and narrow bandwidth imaging of three southern elliptical galaxies which have flat-spectrum active radio cores (NGC 1052, IC 1459 and NGC 6958). All three contain dust and extended low excitation optical line emission, particularly extensive in the case of NGC 1052 which has a large H alpha + (NII) luminosity. Both NGC 1052 and IC 1459 have a spiral morphology in emission-line images. All three display independent strong evidence that a merger or infall event has recently occurred, i.e., extensive and infalling HI gas in NGC 1052, a counter-rotating core in IC 1459 and Malin-Carter shells in NGC 6958. This infall event is the most likely origin for the emission-line gas and dust, and the authors are currently investigating possible excitation mechanisms (Sparks et al. 1990)

Searching for Standards: Disclosure in the Municipal Securities Market

Prokrastinering, eller att mot bättre vetande skjuta upp något, är ett stort problem i samhället i allmänhet och för studenter i synnerhet. I denna artikel beskriver vi en utbildningsmodul om prokrastinering som vi introducerat på två civilingenjörsprogram på KTH, varav denna rapport behandlar datateknikprogrammet där 466 studenter deltog. Utvärderingen hade 100% svarsfrekvens, och visar att 95% av studenterna hade problem med prokrastinering varav 43% hade stora eller mycket stora problem. 88% ansåg att prokrastinering var ett bra tema att ha med i utbildningen, och 57% ansåg att momentet haft positiva effekter på deras studievanor. Endast 7% ansåg att momentet inte hade gett några märkbara effekter på studierna. Då modulen endast kräver ca 8 timmars arbete från studenternas sida anser vi att fördelarna är så stora att denna eller en liknande modul borde ingå i samtliga utbildningsprogram.QC 20131216</p

Diamonds on the Hat: Globular Clusters in The Sombrero Galaxy (M104)

Images from the HST ACS are used to carry out a new photometric study of the globular clusters (GCs) in M104, the Sombrero galaxy. The primary focus of our study is the characteristic distribution function of linear sizes (SDF) of the GCs. We measure the effective radii for 652 clusters with PSF-convolved King and Wilson dynamical model fits. The SDF is remarkably similar to those measured for other large galaxies of all types, adding strong support to the view that it is a "universal" feature of globular cluster systems. We develop a more general interpretation of the size distribution function for globular clusters, proposing that the shape of the SDF that we see today for GCs is strongly influenced by the early rapid mass loss during their star forming stage, coupled with stochastic differences from cluster to cluster in the star formation efficiency (SFE) and their initial sizes. We find that the observed SDF shape can be accurately predicted by a simple model in which the protocluster clouds had characteristic sizes of $0.9 \pm 0.1$ pc and SFEs of $0.3 \pm 0.07$. The colors and luminosities of the M104 clusters show the clearly defined classic bimodal form. The blue sequence exhibits a mass/metallicity relation (MMR), following a scaling of heavy-element abundance with luminosity of $Z \sim L^{0.3}$ very similar to what has been found in most giant elliptical galaxies. A quantitative self-enrichment model provides a good first-order match to the data for the same initial SFE and protocluster size that were required to explain the SDF. We also discuss various forms of the globular cluster Fundamental Plane (FP) of structural parameters, and show that useful tests of it can be extended to galaxies beyond the Local Group.Comment: In press for MNRA

Structural parameters for globular clusters in M31 and generalizations for the fundamental plane

The structures of globular clusters (GCs) reflect their dynamical states and past histories. High-resolution imaging allows the exploration of morphologies of clusters in other galaxies. Surface brightness profiles from new Hubble Space Telescope observations of 34 globular clusters in M31 are presented, together with fits of several different structural models to each cluster. M31 clusters appear to be adequately fit by standard King models, and do not obviously require alternate descriptions with relatively stronger halos, such as are needed to fit many GCs in other nearby galaxies. The derived structural parameters are combined with corrected versions of those measured in an earlier survey to construct a comprehensive catalog of structural and dynamical parameters for M31 GCs with a sample size similar to that for the Milky Way. Clusters in M31, the Milky Way, Magellanic Clouds, Fornax dwarf spheroidal and NGC 5128 define a very tight fundamental plane with identical slopes. The combined evidence for these widely different galaxies strongly reinforces the view that old globular clusters have near-universal structural properties regardless of host environment.Comment: AJ in press; 59 pages including 16 figure

The Electrosphere of Macroscopic "Quark Nuclei": A Source for Diffuse MeV Emissions from Dark Matter

Using a Thomas-Fermi model, we calculate the structure of the electrosphere of the quark antimatter nuggets postulated to comprise much of the dark matter. This provides a single self-consistent density profile from ultrarelativistic densities to the nonrelativistic Boltzmann regime that use to present microscopically justified calculations of several properties of the nuggets, including their net charge, and the ratio of MeV to 511 keV emissions from electron annihilation. We find that the calculated parameters agree with previous phenomenological estimates based on the observational supposition that the nuggets are a source of several unexplained diffuse emissions from the Galaxy. As no phenomenological parameters are required to describe these observations, the calculation provides another nontrivial verification of the dark-matter proposal. The structure of the electrosphere is quite general and will also be valid at the surface of strange-quark stars, should they exist.Comment: 20 Pages, REVTeX4.

WMAP Haze: Directly Observing Dark Matter?

In this paper we show that dark matter in the form of dense matter/antimatter nuggets could provide a natural and unified explanation for several distinct bands of diffuse radiation from the core of the Galaxy spanning over 12 orders of magnitude in frequency. We fix all of the phenomenological properties of this model by matching to x-ray observations in the keV band, and then calculate the unambiguously predicted thermal emission in the microwave band, at frequencies smaller by 10 orders of magnitude. Remarkably, the intensity and spectrum of the emitted thermal radiation are consistent with--and could entirely explain--the so-called "WMAP haze": a diffuse microwave excess observed from the core of our Galaxy by the Wilkinson Microwave Anisotropy Probe (WMAP). This provides another strong constraint of our proposal, and a remarkable nontrivial validation. If correct, our proposal identifies the nature of the dark matter, explains baryogenesis, and provides a means to directly probe the matter distribution in our Galaxy by analyzing several different types of diffuse emissions.Comment: 16 pages, REVTeX4. Updated to correspond with published version: includes additional appendices discussing finite-size effect

Exercise interventions for preventing dementia or delaying cognitive decline in people with mild cognitive impairment

This is the protocol for a review and there is no abstract. The objectives are as follows: To evaluate the effects of exercise interventions for preventing dementia in people with mild cognitive impairment. We refer to Forbes 2015b and Forbes 2015c for the review protocols on exercise interventions for maintaining cognitive function in cognitively healthy people in mid and late life

Exercise interventions for maintaining cognitive function in cognitively healthy people in mid life

This is the protocol for a review and there is no abstract. The objectives are as follows: To evaluate the effects ofexercise interventions on cognitive function in cognitively healthy people in mid life. We refer to Forbes 2015b for the review protocol on Exercise interventions for maintaining cognitive function in cognitively healthy people in late life and to Forbes 2015c for the review protocol on Exercise interventions for prevention of dementia in people with mild cognitive impairment