2008 NVO Summer School Student Prizes

During the 2008 NVO Summer School, students were asked to work on team-based projects using NVO protocols and software in service of astronomical science. At the end of the school when the projects were presented, NVOSS faculty granted awards to the five best projects. Winning projects received financial support to attend and present their work at the upcoming AAS meeting in January 2000 in Long Beach, California.

The following is a list of the winning projects.

Measuring extinction and extinction-distance relation near the galactic plane
Kristen A. Larson, S. G. Navarro

The distance to planetary nebulae near the plane of the Milky Way can be estimated from measured interstellar reddening if the average rates of reddening per unit distance along the lines of sight are known. The reddening-distance relationship in a line of sight can be determined by measuring reddening toward known stars in the field. In this way, we determine the reddening-distance relationship for stars that are in the same field as a planetary nebula, and use the relationship to estimate the distance to the planetary nebula whose reddening can be measured but whose intrinsic magnitude is unknown. We use tools of the National Virtual Observatory in this project to build a compilation of stellar spectral type from a variety of catalogs in the field of view of the planetary nebula. Spectral type is matched with intrinsic colors and magnitudes and catalog photometry for each star in the field to calculate the reddening and distance. We demonstrate the great potential of VO tools for this method, with planetary nebula distances that compare well to previous results. The use of VO tools in this method will be especially powerful when the VO has access to results of future surveys like GAIA. This research was done at the 2008 U.S. National Virtual Observatory Summer School held in Santa Fe, New Mexico on September 3-11, 2008 and sponsored by the National Science Foundation.

Is the Na D Absorption Line Useful For Integrated Light Stellar Population Studies In Galaxies?
Marcel Bergmann, B. Milvang-Jensen

The Sodium Na D absorption line at 5895 Angstroms is one of the strongest absorption features in stellar photospheres, but has been rarely used in integrated light stellar population studies of galaxies. A principal reason why it has not been used is the suspicion that interstellar absorption within the galaxies may enhance or alter the absorption profile of the combined stellar light, thus giving an errant description of the stellar population. As a project undertaken during the National Virtual Observatory Summer School, we have investigated to what extent ISM absorption seems to alter the measurements. We use VO tools to create multiple galaxy samples: a sample expected to have little ISM (cluster galaxies, which are mainly ellipticals), and two samples with higher expected levels of ISM (HI-detected galaxies and morphologically late-type galaxies). After culling the samples to match the same distribution of (older) ages and (higher) metallicities, we find that the Na D vs. velocity dispersion correlation is not significantly different for the samples with and without ISM, and all have similar levels of scatter. Consequently, the Na D line seems like a promising tool for evolutionary studies comparing high and low redshift galaxy samples. Our continuing work focuses on the effects of possible ISM absorption on the line-of-sight velocity profile as derived from the Na D line compared to Mgb and Ca H & K absorption features. This research has made use of data obtained from and software provided by the US National Virtual Observatory, which is sponsored by the National Science Foundation. We thank the US-VO and the NSF for the partial funding they provided to attend this meeting.

Using Virtual Astronomical Observatory Tools for Astronomy 101
Kenneth J. Mighell, K. Garmany, K. Larson, K. D. Eastwood

The Virtual Observatory provides several tools that are useful for educators. With these tools, instructors can easily provide real data to students in an environment that engages student curiosity and builds student understanding. In this poster we demonstrate how the tools Aladin and TOPCAT can be used to enhance astronomy education. The Aladin Sky Atlas is a Virtual Observatory portal from the CDS that displays images, superimposes catalogs, and provides interactive access to data. For illustration, we show an exercise for non-science majors in a college-level astronomy course that introduces students to the HR diagram of star clusters. After launching the pre-loaded Aladin applet, students select their own stars, connecting visual cues of brightness and color to the conceptual meaning behind a quantitative HR diagram. TOPCAT can be linked with Aladin on the desktop to let students analyze their data, perform calculations, and create professional-quality graphs. The basic exercise can be easily expanded to address other learning objectives and provides a launching point for students to access, visualize, and explore multi-wavelength data as they continue in astronomy. As a second example, we show an exercise that uses TOPCAT to do three-dimensional plotting of the positions of open and globular cluster to illustrate galactic structure. Detailed information is available at the following website: http://www.noao.edu/staff/mighell/nvoss2008/ . This research was done at the 2008 U.S. National Virtual Observatory Summer School which was held in Santa Fe, New Mexico on September 3 – 11, 2008 and was sponsored by the National Science Foundation.

Automating Image Import for Google Sky using Virtual Observatory Tools
Jared H. Crossley, R. DuPlain

We have developed a prototype web service that brings the wealth of Virtual Observatory image data to the Google Sky desktop client. The web service, “KML Now!,” presents the user with a simple web interface and requires no specialized knowledge of image conversion, coordinate system conversion, or Google Sky’s KML metadata format. KML Now! makes use of Virtual Observatory Simple Image Access Services to acquire images based on user-input search coordinates. Once images are acquired, open source conversion software is used to generate Sky-compatible image and metadata files; the files are cached on the server for reuse. A “launcher” KML file pointing to all applicable server-side data is returned to the user, and when opened in Google Sky, all images are automatically placed within the desktop client. KML Now! can also operate directly on a user-specified image, without the need for Virtual Observatory interaction. A KML Now! query is coded in URL arguments, which allows it to be easily called from within Google Sky, a feature to be added in future developments. Funding for this project is provided by the National Radio Astronomy Observatory and the National Virtual Observatory, both supported by the National Science Foundation.

Probing the quasar distribution within the Virtual Observatory
G. Barentsen, K. Borne, R. D’Abrusco, O. Laurino, G. Longo, P. Nayak

In the era of massive astronomical datasets, efficient identification of candidate quasars and the reconstruction of their three dimensional distribution in the Universe is a key requirement for constraining some of the main issues regarding the formation and evolution of QSOs. A method for the accurate determination of the photometric redshifts of QSOs based on multiwavelength photometry and a combination of data mining techniques will be discussed. This procedure, specifically suited for accompanying the candidate selection method discussed in D’Abrusco et al. 2008, makes use of specific tools developed under the EuroVO and NVO frameworks for data gathering, pre-processing and mining, while relying on the scaling capabilities of the computing grid.