3,466 research outputs found

    The Stellar Population of Stripped Cluster Spiral NGC 4522: A Local Analog to K+A Galaxies?

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    We present observations of the stripped Virgo Cluster spiral NGC 4522, a clear, nearby example of a galaxy currently undergoing ISM-ICM stripping. Utilizing SparsePak integral field spectroscopy on the WIYN 3.5m telescope and GALEX UV photometry, we present an analysis of the outer disk (r > 3 kpc) stellar population of this galaxy, beyond the HI and Halpha truncation radius. We find that the star formation in the gas-stripped outer disk ceased very recently, ~100 Myr ago, in agreement with previous claims that this galaxy is currently being stripped. At the time of this stripping, data and models suggest that the galaxy experienced a modest starburst. The stripping is occurring in a region of the cluster well outside the cluster core, likely because this galaxy is experiencing extreme conditions from a dynamic ICM due to an ongoing sub-cluster merger. The outer disk has a spectrum of a K+A galaxy, traditionally observed in high-redshift cluster galaxies. In the case of NGC 4522, a K+A spectrum is formed by simple stripping of the interstellar gas by the hot intracluster medium. These data show K+A spectra can be created by cluster processes and that these processes likely extend beyond the cluster core.Comment: 5 pages, 3 figures, accepted for publication in ApJ Letter

    It’s Time to Listen to the Survivors: Understanding Undergraduate College Women’s Choice to Report a Sexual Assault to College Officials

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    The purpose of this study was to add to the existing literature about the lived experience of undergraduate college women between the ages of 18-24 years who experienced a sexual assault while enrolled in college. This study used a semi-structured interview protocol with six undergraduate women, between the ages of 18-22 years, who were enrolled in a Western New York college. The qualitative phenomenological design, along with feminist interviewing practices, provided a deeper understanding of the lived experience of the survivors and the barriers that keep women from reporting their assaults to college officials. Six undergraduate college women shared their experience of being sexually assaulted while in college. Contextual and structural themes were developed from the analysis of the participant interviews, which explored their campus sexual assault. Contextual themes included: (a) lack of definition of the experience; (b) not a big deal, it was my fault; and (c) did not want to get self or others in trouble. Additionally, the structural themes included: (a) mistrust of the reporting process, and (b) lack of knowledge about campus support services and personnel. These themes provided valuable insight to understanding the effects of a sexual assault for college women. The findings indicate a need to improve support services and the manner in which students are asked to report being sexually assaulted and the importance of given students a voice in the develop of policies and procedures

    The materials processing research base of the Materials Processing Center

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    The goals and activities of the center are discussed. The center activities encompass all engineering materials including metals, ceramics, polymers, electronic materials, composites, superconductors, and thin films. Processes include crystallization, solidification, nucleation, and polymer synthesis

    Direct and indirect selection on flowering time, water-use efficiency (WUE, δ (13)C), and WUE plasticity to drought in Arabidopsis thaliana.

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    Flowering time and water-use efficiency (WUE) are two ecological traits that are important for plant drought response. To understand the evolutionary significance of natural genetic variation in flowering time, WUE, and WUE plasticity to drought in Arabidopsis thaliana, we addressed the following questions: (1) How are ecophysiological traits genetically correlated within and between different soil moisture environments? (2) Does terminal drought select for early flowering and drought escape? (3) Is WUE plasticity to drought adaptive and/or costly? We measured a suite of ecophysiological and reproductive traits on 234 spring flowering accessions of A. thaliana grown in well-watered and season-ending soil drying treatments, and quantified patterns of genetic variation, correlation, and selection within each treatment. WUE and flowering time were consistently positively genetically correlated. WUE was correlated with WUE plasticity, but the direction changed between treatments. Selection generally favored early flowering and low WUE, with drought favoring earlier flowering significantly more than well-watered conditions. Selection for lower WUE was marginally stronger under drought. There were no net fitness costs of WUE plasticity. WUE plasticity (per se) was globally neutral, but locally favored under drought. Strong genetic correlation between WUE and flowering time may facilitate the evolution of drought escape, or constrain independent evolution of these traits. Terminal drought favored drought escape in these spring flowering accessions of A. thaliana. WUE plasticity may be favored over completely fixed development in environments with periodic drought

    VIVA, VLA Imaging of Virgo spirals in Atomic gas: I. The Atlas & The HI Properties

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    We present the result of a new VLA HI Imaging survey of Virgo galaxies, VIVA (the VLA Imaging survey of Virgo galaxies in Atomic gas). The survey includes high resolution HI data of 53 carefully selected late type galaxies (48 spirals and 5 irregular systems). The goal is to study environmental effects on HI gas properties of cluster galaxies to understand which physical mechanisms affect galaxy evolution in different density regions, and to establish how far out the impact of the cluster reaches. As a dynamically young cluster, Virgo contains examples of galaxies experiencing a variety of environmental effects. Its nearness allows us to study each galaxy in great detail. We have selected Virgo galaxies with a range of star formation properties in low to high density regions (at the projected distance from M87, d_87=0.3-3.3 Mpc). Contrary to pr evious studies, more than half of the galaxies in the sample (~60%) are fainter than 12 mag in B_T. Overall, the selected galaxies represent the late type Virgo galaxies (S0/a to Sd/Irr) down to m_p<~14.6 fairly well in morphological type, systemic velocity, subcluster membership, HI mass and deficiency. In this paper (VIVA I: the atlas and the HI properties), we present HI maps and properties, and describe the HI morphology and kinematics of individual galaxies in detail (abbreviated).Comment: K band magnitudes for 6 galaxies in Table 3 have been corrected. One of the labels in Figure 8 is corrected and an omission in the acknowledgments has been added. The latter two were correct in the previous astro-ph version but are wrong in the journal version. A full resolution with the complete HI atlas can be downloaded at http://www.astro.yale.edu/viva/pub.htm
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