KPNO REU Students at the 211th AAS Meeting (January 2008)

The opportunity to present the findings of their original research at the most important national meeting of US astronomy is arguably one of the most prized benefits enjoyed by KPNO REU students. All six of the 2007 summer students will attend the 211th meeting of the American Astronomical Society (AAS) in Austin, TX in January 2008.

The abstracts of the REU student posters are reproduced below.

[051.06] VLT Spectroscopy of Six Short-Period Cataclysmic Variables

Rosalie C. McGurk (University of Washington), S. B. Howell (NOAO), E. Mason (ESO)

We present optical spectroscopy of six short-period cataclysmic variable stars obtained with ESO’s 8-meter Very Large Telescope. Four of the stars and their K1 amplitudes are GW Lib, 43.3 km/s; BW Scl, 56.6 km/s; V436 Cen, 77.5 km/s; VY Aqr, 48.7 km/s; and Z Cha, 180.6 km/s. We determined the mass ratio, q, for each system, but found likely unrealistic q values for GW Lib and Z Cha. GW Lib is a low inclination system and its accretion may be more of an accretion ring than an accretion disk. Z Cha’s high inclination and strong hot spot impact the determination of q. V436 Cen’s spectra show a strongly- rising blue continuum and Balmer decrements H_α/H_β and H_δ/H_β indicative an optically thick disk with a hot, thin chromosphere. WZ Sge was observed soon after its 2001 superoutburst. The emission lines were strongly dominated by the S-wave component leading to a unique radial velocity curve. We can model the RV variations as a combination of the underlying, weak binary motion combined with a string hot spot modulation. McGurk’s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[055.10] Tip of the Red Giant Branch Distance of Satellite Dwarfs as a Secondary Distance Indicator to NGC4258

Ferah Munshi1 (U. California, Berkeley), L. Macri (NOAO)

The Tip of the Red Giant Branch (TRGB) is a distance indicator of comparable accuracy to the Cepheid Period-Luminosity relation. We analyzed HST/ACS archival data of three previously unstudied dwarf galaxies that are companions to NGC4258 and located the TRGBs in their I-band Luminosity Functions (LF). By doing so, we obtained an estimate of the distance to NGC4258 that is comparable to the one derived from Cepheids located within the galaxy itself. Munshi’s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[089.02] Comparison Of UV And H-alpha SFR Indicators At Intermediate Redshift: Extraction Of GALEX UV Fluxes

Josiah Walton (University of Arkansas, Fayetteville), A. Esselman (Whitman College), S. Salim (NOAO), J. Lee (Carnegie Observatories)

We present preliminary results of an on-going study of the systematics between two commonly used star formation rate (SFR) indicators, UV and H-alpha emission, at z ~ 0.8. This poster reports on the construction of a PSF-based flux catalog, which effectively deals with object blending, using data from the GALEX ultra-deep imaging survey in the Extended Groth Strip. A companion poster presents the work done to extract H-alpha fluxes from new near-IR narrowband imaging observations in the same region. From the rest-frame far-UV flux and the UV slope, we calculate dust-corrected SFRs. For galaxies at z~0.8 having spectroscopic redshifts in DEEP2, our UV SFRs are compared to those obtained in the H-alpha analysis. We hope our study aids in a better understanding of these two indicators, since the systematics of both have not been extensively studied in the intermediate and high redshift regimes. Walton’s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[089.03] Comparison Of UV And H-alpha SFR Indicators At Intermediate Redshift: Extraction Of H-alpha Fluxes From Near-IR Narrowband Imaging

Andrew R. Esselman (Whitman College), J. Lee (Carnegie Observatories), S. Salim (NOAO), R. Finn (Sienna College), D. Dale (University of Wyoming)

We present preliminary results of an on-going study of the systematics between two commonly used star formation rate (SFR) indicators, UV and H-alpha emission at z ~ 0.8. This poster reports on the measurement of emission-line fluxes from new H-alpha near-IR narrowband imaging in the Extended Groth Strip (EGS), while a companion poster describes the extraction of UV fluxes from ultra-deep GALEX data taken in the same area. Two narrowband filters centered on 1113 and 1184 nm were used to image the EGS in 32 different pointings. The data were taken with the PISCES near-IR imager at the Steward Observatory Bok 2.3m Telescope. Catalogs were produced using Source Extractor and cross-correlated with the DEEP2 redshift dataset to identify true H-alpha emitters in the redshift windows of our filters. The SFR of these galaxies were computed and compared to the SFR computed by GALEX UV photometry. Esselman’s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[094.07] Creation and Control of an Internet Controlled Mars Rover Model

Gabor Angeli (U. California, Berkeley), C. Walker (NOAO)

The latest project in a longstanding correspondence between NOAO Tucson and the CADIAS center in La Serena, Chile focuses on Mars and Mars exploration. The objective was to provide a user-friendly yet moderately versatile imitation of the Spirit and Opportunity MARS rovers to be used by grade school students. In addition to basic motion, the rover that was built is able to take color photographs from a rotating camera, and avoid harmful collisions or structural stress via ‘bumper’ sensors on each of the wheels. The rover is intended to be used remotely via the Internet, and controlled locally via wireless radio. The focus of the project was to create a system that is stable, versatile, and user friendly. The majority of the system was coded in Java, including the micro controller, providing stability and a reliable internet protocol. A partial implementation of Scheme was used as a scripting language, providing an abstraction in the means of communication and control of the robot and allowing for a level of versatility in the range of commands available to the rover and the ease of tweaking those commands. A graphical user interface was implemented to provide a safe means of controlling the rover, creating an ‘action queue’ of safe commands to be sent as a block to the rover. We hope the project will provide a useful education tool for students in Chile, and potentially in the future students in Tucson as well. Angeli’s research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

[137.17] A Prototype Automated Wavefront Sensing Pipeline for the LSST

Timothy Rodigas (U. Virginia), C. F. Claver (NOAO), K. Mighell (NOAO), B. Kuhn (WPKuhn LLC), M. Lang (WPKuhn LLC)

The Large Synoptic Survey Telescope (LSST) is a planned 8.4 meter fast, wide-field telescope. Its ~10 square-degree field-of-view will allow the night sky to be entirely surveyed every four nights. The large structure of the telescope, combined with its fast operating scheme, will require an automated active optics system that can correct for optical distortions to produce sharp, optimal images. The active optics system (AOS) employs wavefront curvature sensing (WCS) located at the four corners of the inscribed square within the 3.5 degree field-of-view. The measured wavefront errors are used to determine the displacements and surface corrections in the AOS. To save operating time, we had to minimize human interaction in the WCS process by making the WCS software as automated as possible. We designed and coded this automated WCS software in a Matlab graphical user interface (GUI), which takes in input data (intra/extra-focal images), automatically cleans the data (bias-subtraction, trimming, removing bad columns), then automatically converts the image data into data that can be passed to the WCS code. The WCS code uses a Fourier-based algorithm to solve the intensity transport equation and estimate the system wavefront errors. These errors can then be corrected for by adjusting the physical components of the telescope’s optical system. Rodigas’ research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.