Time-dependent modeling of TeV-detected, young pulsar wind nebulae

The increasing sensitivity of instruments at X-ray and TeV energies have revealed a large number of nebulae associated with bright pulsars. Despite this large data set, the observed pulsar wind nebulae (PWNe) do not show a uniform behavior and the main parameters driving features like luminosity, magnetization, and others are still not fully understood. To evaluate the possible existence of common evolutive trends and to link the characteristics of the nebula emission with those of the powering pulsar, we selected a sub-set of 10 TeV detections which are likely ascribed to young PWNe and model the spectral energy distribution with a time-dependent description of the nebulae's electron population. In 9 of these cases, a detailed PWNe model, using up-to-date multiwavelength information, is presented. The best-fit parameters of these nebula are discussed, together with the pulsar characteristics. We conclude that TeV PWNe are particle-dominated objects with large multiplicities, in general far from magnetic equipartition, and that relatively large photon field enhancements are required to explain the high level of Comptonized photons observed. We do not find significant correlations between the efficiencies of emission at different frequencies and the magnetization. The injection parameters do not appear to be particularly correlated with the pulsar properties either. We find that a normalized comparison of the SEDs (e.g., with the corresponding spin-down flux) at the same age significantly reduces the spectral distributions dispersion.Comment: 38 pages, 20 figures, 8 tables. Accepted for publication in the Journal of High Energy Astrophysics (JHEAp

Gamma-ray upper limits on magnetars with 6 years of Fermi-LAT observations

We report on the search for gamma-ray emission from 20 magnetars using 6 years of Fermi, Large Area Telescope (LAT) observations. No significant evidence for gamma-ray emission from any of the currently-known magnetars is found. We derived the most stringent upper limits to date on the 0.1--10 GeV emission of Galactic magnetars, which are estimated between $\sim10^{-12}-10^{-11}$ erg s$^{-1}$ cm$^{-2}$. Gamma-ray pulsations were searched for the four magnetars having reliable ephemerides over the observing period, but none were detected. On the other hand, we also studied the gamma-ray morphology and spectra of seven Supernova Remnants associated or adjacent to the magnetars.Comment: 22 pages, 4 figures, 2 tables, submitted to Ap

Quantifying slope-channel coupling in an active gully and fan complex at Tarndale, Waipaoa catchment, New Zealand

Two RIEGL LMS‐Z420i scanner surveys (November 2007 and November 2008) of the Tarndale Gully complex and its associated fan were used to generate a digital elevation model (DEM) of difference in order to quantify gully‐fan‐channel connectivity. The Te Weraroa Stream, into which the first order Tarndale system feeds, is buffered from sediment generated by the gully complex by a fan. Sediment yields and the role of the fan in buffering Te Weraroa Stream are inferred from the TLS of the entire complex. DEM analysis suggests that c.25% of material derived from the gully is buffered from the stream by being stored in the fan. This figure was applied to fan behaviour since December 2004, mapped on nine successive occasions using detailed GPS surveys to get a longer‐term picture of sediment supply within the system and appraise a qualitative assessment of connectivity constructed on the basis of fan behaviour alone

Mosaic: A Lifetime of Poems

In hopes of providing a clearer picture of the aging process and its effects on our personalities, follow this collection of poems through diary-like entries of individuals navigating their lives from daycare, heartbreak, and loneliness. The impact that development can have on our psychological well-being and brains is fascinating and feels familiar. Why do we see the world so differently when we are young? As we grow older, what is so important that makes us shift how we view ourselves and our environment multiple times? It is often seen that each generation shares like-mindedness throughout their lives – why

The Joint Impact Of Parent Health Efficacy And Child Temperament On Child Health Outcomes

Children and adolescents in the United States have high rates of obesity due to several factors including low rates of physical exercise. Parents greatly impact children\u27s short and long-term health behaviors through multiple mechanisms. The role of parental factors such as health self-efficacy in interaction with child temperament is underexplored. This present study had two primary aims: 1) to examine the main effects of parent health efficacy on child physical activity and body mass index (BMI) percentile; 2) to explore the impact of parent health efficacy as a function of child temperament and the main effects of temperament on children\u27s physical activity and BMI percentile. In the present study, 123 mother and child pairs from the greater Chicago area completed self-report measures regarding physical activity, child BMI percentile, and personality along with tracking child’s physical activity with a fitness tracker. A series of regressions were conducted showing that: the interaction term of parental nutritional efficacy and child temperament of effortful control significantly predicted child physical activity (b = 2.029, p \u3c .049) and the interaction term of parental nutritional efficacy and child temperament of surgency significantly predicted child BMI percentile (b = 2.095, p \u3c .033). This study was conducted to better understand the impact parents’ self-efficacy of their own health behaviors on child’s health outcomes. This study also has the potential to identify subgroups of families who may benefit from culturally tailored interventions