The Nature of the Secondary Star in the Black Hole X-Ray Transient V616 Mon (=A0620-00)

We have used NIRSPEC on Keck II to obtain $K$-band spectroscopy of the low mass X-ray binary V616 Mon (= A0620$-$00). V616 Mon is the proto-typical soft x-ray transient containing a black hole primary. As such it is important to constrain the masses of the binary components. The modeling of the infrared observations of ellipsoidal variations in this system lead to a derived mass of 11.0 M_{\sun} for the black hole. The validity of this derivation has been called into question due to the possiblity that the secondary star's spectral energy distribution is contaminated by accretion disk emission (acting to dilute the variations). Our new $K$-band spectrum of V616 Mon reveals a late-type K dwarf secondary star, but one that has very weak $^{\rm 12}$CO absorption features. Comparison of V616 Mon with SS Cyg leads us to estimate that the accretion disk supplies only a small amount of $K$-band flux, and the ellipsoidal variations are not seriously contaminated. If true, the derived orbital inclination of V616 Mon is not greatly altered, and the mass of the black hole remains large. A preliminary stellar atmosphere model for the $K$-band spectrum of V616 Mon reveals that the carbon abundance is approximately 50% of the solar value. We conclude that the secondary star in V616 Mon has either suffered serious contamination from the accretion of supernova ejecta that created the black hole primary, or it is the stripped remains of a formerly more massive secondary star, one in which the CNO cycle had been active.Comment: 20 pages, 5 figure

A Preschool Aged Obesity Prevention Project Designed to Increase Moderate to Vigorous Physical Activity

Purpose: The purpose of Juntos Y Saludables (Get Healthy Together [GHT]) is to reduce the prevalence of childhood obesity by focusing on physical activity and healthy eating. GHT is an ongoing project, with phase one of three completed in May 2010.The GHT program was implemented in the Edgewood Independent School District’s Head Start centers located in San Antonio, TX. These centers were selected due to high prevalence of obesity (50%) and diabetes in children and adults living in the community. Method: The gross motor intervention was implemented at two of the three centers. The intervention consisted of teacher training and supplemental gross motor resources (lesson plans and activity resources). The System for Observing Fitness Instruction Time (SOFIT) was used to assess the amount of time spent in moderate to vigorous physical activity (MVPA) and the Learning Accomplishment Profile – 3rd Editions (LAP-3) were used to evaluate the program’s effects on gross motor development. Results: At the start of the project, the two intervention centers were spending eleven minutes (roughly 24%) of their gross motor class period engaged in MVPA while at the end of the program sixteen minutes (roughly 35%) of the time was spent engaged in MVPA. There was an overall increase in physical activity (P\u3c0.001) and MVPA (P\u3c0.019) levels in both intervention and control centers. A similar linear improvement was also observed in the LAP-3 results. At the conclusion of the project, all of the students either met or were above their gross motor developmental ages. Conclusion: Through the implementation of the GHT Gross Motor intervention a significant increase occurred in the student’s gross motor skills and the percentage of time spent in MVPA

Probing the Pulsar Wind Nebula of PSR B0355+54

We present XMM-Newton and Chandra X-ray observations of the middle-aged radio pulsar PSR B0355+54. Our X-ray observations reveal emission not only from the pulsar itself, but also from a compact diffuse component extending ~50'' in the opposite direction to the pulsar's proper motion. There is also evidence for the presence of fainter diffuse emission extending ~5' from the point source. The compact diffuse feature is well-fitted with a power-law, the index of which is consistent with the values found for other pulsar wind nebulae. The morphology of the diffuse component is similar to the ram-pressure confined pulsar wind nebulae detected for other sources. The X-ray emission from the pulsar itself is described well by a thermal plus power-law fit, with the thermal emission most likely originating in a hot polar cap.Comment: 9 pages (uses emulateapj.cls), 8 figures, 2 tables, accepted for publication in Ap