279 research outputs found

    Physical properties and morphology of a newly identified compact z=4.04 lensed submillimeter galaxy in Abell 2218

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    We present the identification of a bright submm source, SMMJ163555.5+661300, detected in the lensing cluster Abell2218, for which we have accurately determined the position using observations from the Submillimeter Array (SMA). The identified optical counterpart has a spectroscopic redshift of z=4.044+-0.001 if we attribute the single emission line detected at lambda=6140AA to Lyman-alpha. This redshift identification is in good agreement with the optical/near-infrared photometric redshift as well as the submm flux ratio S_450/S_850~1.6, the radio-submm flux ratio S_1.4/S_850 < 0.004, and the 24um to 850um flux ratio S_24/S_850 < 0.005. Correcting for the gravitational lensing amplification of ~5.5, we find that the source has a far-infrared luminosity of 1.3x10^12 Lsun, which implies a star formation rate of 230 Msun/yr. This makes it the lowest-luminosity SMG known at z>4 to date. Previous CO(4-3) emission line obserations yielded a non-detection, for which we derived an upper limit of the CO line luminosity of L'_CO = 0.3x10^10 K km/s/pc^2, which is not inconsistent with the L'_CO - L_FIR relation for starburst galaxies. The best fit model to the optical and near-infrared photometry give a stellar population with an age of 1.4 Gyr and a stellar mass of 1.6x10^10 Msun. The optical morphology is compact and in the source plane the galaxy has an extent of ~6kpc x 3kpc with individual star forming knots of <500 pc in size. J163556 is not resolved in the SMA data and we place a strict upper limit on the size of the starburst region of 8kpc x 3kpc, which implies a lower limit on the star formation rate surface density of 12 Msun/yr/kpc^2. The redshift of J163556 extends the redshift distribution of faint, lensed SMGs, and we find no evidence that these have a different redshift distribution than bright SMGs.Comment: Accepted for publication in ApJ. 11 pages, 7 figure

    Unveiling Palomar 2: The Most Obscure Globular Cluster in the Outer Halo

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    We present the first color-magnitude study for Palomar 2, a distant and heavily obscured globular cluster near the Galactic anticenter. Our (V,V-I) color-magnitude diagram (CMD), obtained with the UH8K camera at the CFHT, reaches V(lim) = 24 and clearly shows the principal sequences of the cluster, though with substantial overall foreground absorption and differential reddening. The CMD morphology shows a well populated red horizontal branch with a sparser extension to the blue, similar to clusters such as NGC 1261, 1851, or 6229 with metallicities near [Fe/H] = -1.3.Fromanaverageofseveralindicators,weestimatetheforegroundreddeningatE(BV)=1.24+0.07andobtainatruedistancemodulus(mM)0=17.1+0.3. From an average of several indicators, we estimate the foreground reddening at E(B-V) = 1.24 +- 0.07 and obtain a true distance modulus (m-M)_0 = 17.1 +- 0.3, placing it about 34 kpc from the Galactic center. We use starcounts of the bright stars to measure the core radius, half-mass radius, and central concentration of the cluster. Its integrated luminosity is M_V = -7.9, making it clearly brighter and more massive than most other clusters in the outer halo.Comment: 25 pages, aastex, with 8 postscript figures; accepted for publication in AJ, September 1997. Also available by e-mail from [email protected]. Please consult Harris directly for (big) postscript files of Figures 1a,b (the images of the cluster

    Molecular tendrils feeding star formation in the Eye of the Medusa - The Medusa merger in high resolution 12CO 2-1 maps

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    Studying molecular gas properties in merging galaxies gives us important clues to the onset and evolution of interaction-triggered starbursts. NGC4194 is particularly interesting to study since its FIR-to-CO luminosity ratio rivals that of ULIRGs,despite its lower luminosity compared to ULIRGs, which indicates a high star formation efficiency that is relative to even most spirals and ULIRGs.We study the molecular medium at an angular resolution of 0.65"x .52" through our observations of CO2-1 emission using the SMA. We compare our CO2-1 maps with optical HST and high angular resolution radio continuum images to study the relationship between molecular gas and other components of the starburst region. The molecular gas is tracing the complicated dust lane structure of NGC4194 with the brightest emission being located in an off-nuclear ring-like structure with ~320pc radius, the Eye of the Medusa. The bulk CO emission of the ring is found south of the kinematical center of NGC4194. The northern tip of the ring is associated with the galaxy nucleus, where the radio continuum has its peak. A prominent, secondary emission maximum in the radio continuum is located inside the molecular ring. This suggests that the morphology of the ring is partially influenced by massive supernova explosions. From the combined evidence, we propose that the Eye of the Medusa contains a shell of swept up material where we identify a number of giant molecular associations. We propose that the Eye may be the site of an efficient starburst of 5-7M_sun/yr, but it would still constitute only a fraction of the 30-50M_sun/yr SFR of NGC4194. Furthermore, we find that ~50% of the molecular mass of NGC4194 is found in extended filamentary-like structures tracing the minor and major axis dust lanes. We suggest that molecular gas is transported along these lanes providing the central starburst region with fuel.Comment: accepted for publication in A&A, 12 pages, 9 figure

    Effects of Transferable Skills Workshops on the Career Self-Efficacy of College Student-Athletes

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    This study was designed to investigate the effects of two types of transferable skills workshops on the career self-efficacy of intercollegiate student-athletes. Participants were 79 college student-athletes (45 males [30 football players and 15 basketball players] and 34 females [14 softball players and 20 soccer players]) enrolled at a small NCAA Division III institution. Student-athletes (N=79) were randomly assigned to one of three conditions: (a) a control condition that involved viewing a video on sports nutrition, (b) an unaugmented transferable skills workshop that was based on the model suggested by Petitpas and Schwartz (1989), and (c) an augmented transferable skills workshop similar to the unaugmented workshop but including completion of a self-report inventory designed to help athletes identify sport-related skills that can transfer to other domains. All participants completed the Career Decision Self-Efficacy Short-Form (COSE-SF; Betz & Taylor, 200 I) before and after the workshops. Analyses of covariance (ANCOVAs) with COSE-SF pretest scores as a covariate revealed that the augmented transferable skills workshop produced significantly greater increases in career self-efficacy than the unaugmented transferable skills workshop and the control condition. Paired samples t-tests indicated that both transferable skills workshops, but not the control condition, produced statistically significant gains in career self-efficacy. The results suggest that both transferable skills workshops can have a positive influence on the career self-efficacy of student-athletes and that a standardized transferable skills inventory can be a helpful tool in enhancing the ability of student-athletes to identify transferable skills that can increase their career self-efficacy. The career self-efficacy level of student-athletes who participated in the transferable skills workshops increased significantly compared to that of the control group. In addition, participants who completed the TSI as part of their transferable skills workshop showed higher levels of career self-efficacy than student-athletes who did not complete the TSI

    College Adjustment of Football Players: Predictors of First Semester Adjust to College among NCAA Division III Intercollegiate Football Players

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    This study examined predictors of first-semester adjustment to college among 48 first-year intercollegiate football players. Participants completed measures oflife stress, social support, quality of their relationship with parents, quality of their roommate relationship, sport satisfaction, athletic identity, and adjustment to college near the end of the first semester. The predictor variables accounted for 43% of the variance in adjustment to college, with quality of the roommate relationship and sport satisfaction emerging as significant (p < .05) predictors of adjustment. The results highlight the role of social and sport-related factors in how well first-year intercollegiate football players adjust to college. Recommendations for facilitating positive adjustment were provided. The more favorably participants perceived the relationship with their roommates and the more satisfied they were with their involvement in football, the better their adjustment near the end of the first semester of college. Contrary to the hypothesized pattern of results, however, factors found previously to relate to adjustment to college in the general student body (i.e., life stress, social support, and relationship with parents) were not associated with the football players' adjustment to college. Social support did not moderate the relationship between life stress and adjustment, and athletic identity did not moderate the relationship between sport satisfaction and adjustment. The failure of life stress, social support, and parent relationship to predict adjustment to college among first-year intercollegiate football players is surprising in light of research documenting associations between these variables and adjustment to college for the general student population (Compas et al., 1986; Holmbeck & Wandrei,1993; Prancer et al., 2000; Pratt et al., 2000; Wintre & Yaffe, 2000)

    Molecular Gas in Candidate Double-Barred Galaxies II. Cooler, Less Dense Gas Associated with Stronger Central Concentrations

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    We have performed a multi-transition CO study of the centers of seven double-barred galaxies that exhibit a variety of molecular gas morphologies to determine if the molecular gas properties are correlated with the nuclear morphology and star forming activity. Near infrared galaxy surveys have revealed the existence of nuclear stellar bars in a large number of barred or lenticular galaxies. High resolution CO maps of these galaxies exhibit a wide range of morphologies. Recent simulations of double-barred galaxies suggest that variations in the gas properties may allow it to respond differently to similar gravitational potentials. We find that the 12CO J=3-2/J=2-1 line ratio is lower in galaxies with centrally concentrated gas distributions and higher in galaxies with CO emission dispersed around the galactic center in rings and peaks. The 13CO/12CO J=2-1 line ratios are similar for all galaxies, which indicates that the J=3-2/J=2-1 line ratio is tracing variations in gas temperature and density, rather than variations in optical depth. There is evidence that the galaxies which contain more centralized CO distributions are comprised of molecular gas that is cooler and less dense. Observations suggest that the star formation rates are higher in the galaxies containing the warmer, denser, less centrally concentrated gas. It is possible that either the bar dynamics are responsible for the variety of gas distributions and densities (and hence the star formation rates) or that the star formation alone is responsible for modifying the gas properties.Comment: 27 pages + 6 figures; to appear in the April 20, 2003 issue of Ap

    Molecular Gas in Candidate Double Barred Galaxies III. A Lack of Molecular Gas?

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    Most models of double-barred galaxies suggest that a molecular gas component is crucial for maintaining long-lived nuclear bars. We have undertaken a CO survey in an attempt to determine the gas content of these systems and to locate double barred galaxies with strong CO emission that could be candidates for high resolution mapping. We observed 10 galaxies in CO J=2-1 and J=3-2 and did not detect any galaxies that had not already been detected in previous CO surveys. We preferentially detect emission from galaxies containing some form of nuclear activity. Simulations of these galaxies require that they contain 2% to 10% gas by mass in order to maintain long-lived nuclear bars. The fluxes for the galaxies for which we have detections suggest that the gas mass fraction is in agreement with these models requirements. The lack of emission in the other galaxies suggests that they contain as little as 7 x 10^6 solar masses of molecular material which corresponds to < 0.1% gas by mass. This result combined with the wide variety of CO distributions observed in double barred galaxies suggests the need for models of double-barred galaxies that do not require a large, well ordered molecular gas component.Comment: 17 pages (3 figures embedded on pg 17). To appear in the March 10 issue of the Astrophysical Journa

    Planck's dusty GEMS. V. Molecular wind and clump stability in a strongly lensed star-forming galaxy at z=2.2

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    We report the discovery of a molecular wind signature from a massive intensely star-forming clump of a few 10910^9 Msun, in the strongly gravitationally lensed submillimeter galaxy "the Emerald" (PLCK_G165.7+49.0) at z=2.236. The Emerald is amongst the brightest high-redshift galaxies on the submillimeter sky, and was initially discovered with the Planck satellite. The system contains two magnificient structures with projected lengths of 28.5" and 21" formed by multiple, near-infrared arcs, falling behind a massive galaxy cluster at z=0.35, as well as an adjacent filament that has so far escaped discovery in other wavebands. We used HST/WFC3 and CFHT optical and near-infrared imaging together with IRAM and SMA interferometry of the CO(4-3) line and 850 μ\mum dust emission to characterize the foreground lensing mass distribution, construct a lens model with Lenstool, and calculate gravitational magnification factors between 20 and 50 in most of the source. The majority of the star formation takes place within two massive star-forming clumps which are marginally gravitationally bound and embedded in a 9×10109 \times 10^{10} Msun, fragmented disk with 20% gas fraction. One of the clumps shows a pronounced blue wing in the CO(4-3) line profile, which we interpret as a wind signature. The mass outflow rates are high enough for us to suspect that the clump might become unbound within a few tens of Myr, unless the outflowing gas can be replenished by gas accretion from the surrounding disk. The velocity offset of -200 km s1^{-1} is above the escape velocity of the clump, but not that of the galaxy overall, suggesting that much of this material might ultimately rain back onto the galaxy and contribute to fueling subsequent star formation.Comment: 24 pages, 13 Figures, accepted for publication in A&

    A psycho-educational curriculum for sport career transition practitioners: Development and evaluation

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    Research question: This paper is an integration of three studies. Study 1 investigates sport career transition organisational intervention programmes for high performance athletes and training and development programmes for sport career transition practitioners in order to find a research gap with regard to sport career transition supporting services. A psycho-educational curriculum was developed for sport career transition practitioner in Study 2 to fill the research gap. In Study 3, the curriculum was examined to see if the curriculum contributed to enhancing practitioners’ confidence in key competences.  Research methods: A range of methods were applied to the studies including One Group Pre- and Post-test design, Case Study, Focus Group, Semi-Structured Interview, two-round Delphi-Method and Questionnaires. The data for Study 1 collected from 19 countries worldwide and total 16 participants based in seven different countries were invited to development and evaluation of the curriculum.  Results and Findings: A novel psycho-educational curriculum for sport career transition practitioner was developed and evaluated concerning four competences as a form of curriculum package. The findings revealed that the curriculum package increased the participants’ confidence in key competences concerning sport career transition.  Implications: The findings deepen the knowledge of sport career transition in the areas of organisational intervention programmes focusing on high performance athletes and sport career transition practitioners. These findings contribute to modifying the Conceptual Model of Adaptation to Career Transition (Lavallee, Park, & Taylor, 2014) by strengthening the organisational intervention perspective and applied work in respect of sporting organisation management strategie

    Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star

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    We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN 2011dh using data from the Swift and Chandra satellites, placing it among the best studied X-ray supernovae to date. We further present millimeter and radio data obtained with the SMA, CARMA, and EVLA during the first three weeks after explosion. Combining these observations with early optical photometry, we show that the panchromatic dataset is well-described by non-thermal synchrotron emission (radio/mm) with inverse Compton scattering (X-ray) of a thermal population of optical photons. In this scenario, the shock partition fractions deviate from equipartition by a factor, (e_e/e_B) ~ 30. We derive the properties of the shockwave and the circumstellar environment and find a shock velocity, v~0.1c, and a progenitor mass loss rate of ~6e-5 M_sun/yr. These properties are consistent with the sub-class of Type IIb SNe characterized by compact progenitors (Type cIIb) and dissimilar from those with extended progenitors (Type eIIb). Furthermore, we consider the early optical emission in the context of a cooling envelope model to estimate a progenitor radius of ~1e+11 cm, in line with the expectations for a Type cIIb SN. Together, these diagnostics are difficult to reconcile with the extended radius of the putative yellow supergiant progenitor star identified in archival HST observations, unless the stellar density profile is unusual. Finally, we searched for the high energy shock breakout pulse using X-ray and gamma-ray observations obtained during the purported explosion date range. Based on the compact radius of the progenitor, we estimate that the breakout pulse was detectable with current instruments but likely missed due to their limited temporal/spatial coverage. [Abridged]Comment: (27 pages, 5 figures, 2 tables, final version to appear in ApJ
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