Tucson, AZ, United States
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Jacoby G.H.,WIYN Observatory | Kronberger M.,Deepskyhunters Collaboration | Patchick D.,Deepskyhunters Collaboration | Teutsch P.,Deepskyhunters Collaboration | And 10 more authors.
Publications of the Astronomical Society of Australia | Year: 2010

Recent Hα surveys such as SHS and IPHAS have improved the completeness of the Galactic planetary nebula (PN) census. We now know of ∼3000 PNe in the Galaxy, but this is far short of most estimates, typically ∼25 000 or more for the total population. The size of the Galactic PN population is required to derive an accurate estimate of the chemical enrichment rates of nitrogen, carbon, and helium. In addition, a high PN count (>20 000) is strong evidence that most main-sequence stars of mass 1-8 M⊙ will go through a PN phase, while a low count (<10 000) argues that special conditions (e.g. close binary interactions) are required to form a PN. We describe a technique for finding hundreds more PNe using the existing data collections of the digital sky surveys, thereby improving the census of Galactic PNe. © Astronomical Society of Australia 2010.

Pang X.,University of Heidelberg | Grebel E.K.,University of Heidelberg | Allison R.J.,University of Heidelberg | Goodwin S.P.,University of Sheffield | And 4 more authors.
Astrophysical Journal | Year: 2013

We present deep Hubble Space Telescope/Wide Field and Planetary Camera 2 photometry of the young HD 97950 star cluster in the giant H II region NGC 3603. The data were obtained in 1997 and 2007 permitting us to derive membership based on proper motions of the stars. Our data are consistent with an age of 1 Myr for the HD 97950 cluster. A possible age spread, if present in the cluster, appears to be small. The global slope of the incompleteness-corrected mass function for member stars within 60″ is Γ = -0.88 ± 0.15, which is flatter than the value of a Salpeter slope of -1.35. The radially varying mass function shows pronounced mass segregation ranging from slopes of -0.26 ± 0.32 in the inner 5″ to -0.94 ± 0.36 in the outermost annulus (40″-60″). Stars more massive than 50 M ⊙ are found only in the cluster center. The Λ minimum spanning tree technique confirms significant mass segregation down to 30 M ⊙. The dependence of Λ on mass, i.e., that high-mass stars are more segregated than low-mass stars, and the (weak) dependence of the velocity dispersion on stellar mass might imply that the mass segregation is dynamical in origin. While primordial segregation cannot be excluded, the properties of the mass segregation indicate that dynamical mass segregation may have been the dominant process for segregation of high-mass stars. © 2013. The American Astronomical Society. All rights reserved.

Sawyer D.G.,National Optical Astronomy Observatory | Daly P.N.,National Optical Astronomy Observatory | Howell S.B.,National Optical Astronomy Observatory | Hunten M.R.,National Optical Astronomy Observatory | Schweiker H.,WIYN Observatory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

A project is currently underway to upgrade the Kitt Peak National Observatory (KPNO) Mosaic-1 Imager, an 8192 x 8192 pixel CCD array used on the Mayall 4-meter and WIYN 0.9-meter telescopes. Mosaic-1 has been a heavily subscribed instrument by the US astronomical community since it was commissioned more than a decade ago. In recent years, however, the reliability and efficiency of Mosaic-1 has declined due to aging and failing components. In addition, servicing has become more and more difficult as spare parts are used up, replacement parts become unavailable, and technical expertise for the out-dated controller technology diminishes. The Mosaic-1 upgrade project addresses these reliability and servicing concerns by replacing the CCDs with modern detectors and replacing the controllers with a MONSOON image acquisition system. The upgrade will also enhance the scientific productivity of the instrument through reduced read times, lower read noise, and improved quantum efficiency. We will describe the project status, the technical requirements related to the installation of new CCD detectors and MONSOON controllers, the configuration of the system, and integration of the system into the existing instrument and telescope environments. © 2010 Copyright SPIE - The International Society for Optical Engineering.

Young M.D.,Indiana University | Kotulla R.,University of Wisconsin - Milwaukee | Gopu A.,Indiana University | Liu W.,WIYN Observatory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

As imaging systems improve, the size of astronomical data has continued to grow, making the transfer and processing of data a significant burden. To solve this problem for the WIYN Observatory One Degree Imager (ODI), we developed the ODI-Portal, Pipeline, and Archive (ODI-PPA) science gateway, integrating the data archive, data reduction pipelines, and a user portal. In this paper, we discuss the integration of the QuickReduce (QR) pipeline into PPA's Tier 2 processing framework. QR is a set of parallelized, stand-alone Python routines accessible to all users, and operators who can create master calibration products and produce standardized calibrated data, with a short turn-around time. Upon completion, the data are ingested into the archive and portal, and made available to authorized users. Quality metrics and diagnostic plots are generated and presented via the portal for operator approval and user perusal. Additionally, users can tailor the calibration process to their specific science objective(s) by selecting custom datasets, applying preferred master calibrations or generating their own, and selecting pipeline options. Submission of a QuickReduce job initiates data staging, pipeline execution, and ingestion of output data products all while allowing the user to monitor the process status, and to download or further process/analyze the output within the portal. User-generated data products are placed into a private user-space within the portal. ODI-PPA leverages cyberinfrastructure at Indiana University including the Big Red II supercomputer, the Scholarly Data Archive tape system and the Data Capacitor shared file system. © 2014 SPIE.

Harbeck D.,WIYN Observatory | Gallagher III J.,University of Wisconsin - Madison | Crnojevic D.,University of Edinburgh
Monthly Notices of the Royal Astronomical Society | Year: 2012

We investigate the star cluster population in the outer parts of the starburst galaxy NGC 5253 using archive images taken with the Hubble Space Telescope's Advanced Camera for Surveys. Based on the F415W, F555W and F814W photometry ages and masses are estimated for bona fide star cluster candidates. We find three potentially massive (≥10 5 M ⊙) star clusters at ages of the order of 1-2 Gyr, implying, if confirmed, a high global star formation rate in NGC 5253 during that epoch. This result underlines earlier findings that the current starburst is just one episode in a very active dwarf galaxy. © 2012 The Authors Monthly Notices of the Royal Astronomical Society © 2012 RAS.

Mosby G.,University of Wisconsin - Madison | Tremonti C.A.,University of Wisconsin - Madison | Hooper E.J.,University of Wisconsin - Madison | Hooper E.J.,WIYN Observatory | And 3 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2014

To study the effect of supermassive black holes (SMBHs) on their host galaxies it is important to study the hosts when the SMBH is near its peak activity. A method to investigate the host galaxies of high luminosity quasars is to obtain optical spectra at positions offset from the nucleus where the relative contribution of the quasar and host is comparable. However, at these extended radii the galaxy surface brightness is often low (20-22 mag arcsec-2) and the resulting spectrum might have such low signal-to-noise ratio (S/N) that it hinders analysis with standard stellar population modelling techniques. To address this problem, we have developed a method that can recover galaxy star formation histories (SFHs) from rest-frame optical spectra with S/N ~ 5 Å-1. This method uses the statistical technique diffusion k-means to tailor the stellar population modelling basis set. Our diffusion k-means minimal basis set, composed of four broad age bins, is successful in recovering a range of galaxy SFHs. Additionally, using an analytic prescription for seeing conditions, we are able to simultaneously model scattered quasar light and the SFH of quasar host galaxies (QHGs). We use synthetic data to compare results of our novel method with previous techniques. We also present the modelling results on a previously published QHG and show that galaxy properties recovered from a diffusion k-means basis set are less sensitive to noise added to this QHG spectrum. Our new method has a clear advantage in recovering information from QHGs and could also be applied to the analysis of other low S/N galaxy spectra such as those typically obtained for high redshift objects or integral field spectroscopic surveys. © 2014 The Authors.

Lesser M.,University of Arizona | Ouellette D.,University of Arizona | Boroson T.,NOAO | Harbeck D.,WIYN Observatory | And 6 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

The WIYN One Degree Imager (ODI) will provide a one degree field of view for the WIYN 3.5 m telescope located on Kitt Peak near Tucson, Arizona. Its focal plane consists of an 8x8 grid of Orthogonal Transfer Array (OTA) CCD detectors. These detectors are the STA2200 OTA CCDs designed and fabricated by Semiconductor Technology Associates, Inc. and backside processed at the University of Arizona Imaging Technology Laboratory. Several lot runs of the STA2200 detectors have been fabricated. We have backside processed devices from these different lots and provide detector performance characterization, including noise, CTE, cosmetics, quantum efficiency, and some orthogonal transfer characteristics. We discuss the performance differences for the devices with different silicon thickness and resistivity. A fully buttable custom detector package has been developed for this project which allows hybridization of the silicon detectors directly onto an aluminum nitride substrate with an embedded pin grid array. This package is mounted on a silicon-aluminum alloy which provides a flat imaging surface of less than 20 microns peakvalley at the -100 C operating temperature. Characterization of the package performance, including low temperature profilometry, is described in this paper. © 2012 SPIE-IS&T.

Yeatts A.K.,WIYN Observatory | Ivens J.,WIYN Observatory | Harbeck D.,WIYN Observatory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The WIYN One Degree Imager (ODI) exposure system must drive multiple complex subsystems requiring large amounts of configuration information that may change substantially between exposures. The mosaic OTA focal plane provides up to 64 streams of image data during readout or 512 ROI video streams for guidance or real time photometry. The work flows and instrument operation sequences are numerous, and are evolving to adapt to the new capabilities the mosaic OTA (Orthogonal Transfer Array) camera presents. By making scripting data driven, the ODI exposure system provides a very flexible, but structured and powerful paradigm for instrumentation process control and operation. © 2010 SPIE.

Ivens J.,WIYN Observatory | Yeatts A.,WIYN Observatory | Harbeck D.,WIYN Observatory | Martin P.,WIYN Observatory
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

User interfaces (UIs) are a necessity for almost any data acquisition system. The development team for the WIYN One Degree Imager (ODI) chose to develop a user interface that allows access to most of the instrument control for both scientists and engineers through the World Wide Web, because of the web's ease of use and accessibility around the world. Having a web based UI allows ODI to grow from a visitor-mode instrument to a queue-managed instrument and also facilitate remote servicing and troubleshooting. The challenges of developing such a system involve the difficulties of browser inter-operability, speed, presentation, and the choices involved with integrating browser and server technologies. To this end, the team has chosen a combination of Java, JBOSS, AJAX technologies, XML data descriptions, Oracle XML databases, and an emerging technology called the Google Web Toolkit (GWT) that compiles Java into Javascript for presentation in a browser. Advantages of using GWT include developing the front end browser code in Java, GWT's native support for AJAX, the use of XML to describe the user interface, the ability to profile code speed and discover bottlenecks, the ability to efficiently communicate with application servers such as JBOSS, and the ability to optimize and test code for multiple browsers. We discuss the inter-operation of all of these technologies to create fast, flexible, and robust user interfaces that are scalable, manageable, separable, and as much as possible allow maintenance of all code in Java. © 2010 SPIE.

Jacoby G.H.,NOAO | Jacoby G.H.,WIYN Observatory | Howell S.B.,NOAO | Harbeck D.R.,WIYN Observatory | Sawyer D.G.,NOAO
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

QUOTA is an 8Kx8K (16'x16') optical imager using four 4Kx4K orthogonal transfer CCDs arrays (OTAs). Each OTA has 64 nearly independent CCDs having 480x494 12μm pixels. By reading out several of the CCDs rapidly (20 Hz), the centroids of the stars in those CCDs can be used to measure image motion due to atmospheric effects, telescope shake, and guide errors. Motions are fed back to the remaining 250 CCDs that continue to integrate normally, allowing a shift of the collecting charge packets so that they always fall under the moving star images, thereby effecting low order adaptive optics tip/tilt correction in the silicon to improve image quality. As a bonus, the stars that are read rapidly can be studied for high speed photometric variability. QUOTA was conceived to be a prototype for WIYN's 32Kx32K One Degree Imager (ODI), providing a means to test and advance the technical developments for the larger imager (e.g., detectors, controllers, optics, coatings, cooling, and software). QUOTA will have been to the WIYN 3.5-m telescope only twice in its current configuration, but it provided a wealth of information that has been useful to the engineering of ODI. We focus on the areas in which ODI has benefited from QUOTA in this report. © 2010 Copyright SPIE - The International Society for Optical Engineering.

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