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Unremarkable on the Face of It

Description: This paper was part of a series by the Smithsonian Photography Initiative 'Click! Photography Changes Everything'. This paper discusses family photographs and how sometimes seemingly unremarkable snapshots can be truly remarkable.
Date: December 3, 2009
Creator: O'Connor, Brian Clark
Partner: UNT College of Information

EXIF and Electric Boat

Description: This photograph shows a Nikon camera on a tripod in the middle of a an electric boat. The electric boat is sitting on the edge of the water. Over the image, photographic information is listed in white font.
Date: unknown
Creator: O'Connor, Brian Clark
Partner: UNT College of Information

FPS-vidicon television camras for ultrafast-scan data acquisition

Description: Two ultrafast-scan (<8 ms/field) television (TV) camera prototypes have been developed for closed-circuit data-acquisition applications. The line and field rates are quasi-continuously adjustable. The number of lines, the integration duty cycle, and the scan direction are among the other adjustable parameters. Typical resolution at the fastest scan rate is >500 TV lines per picture height with a corresponding dynamic range (to light input) of more than 100. The cameras use the unique properties of FPS vidicons and specially designed electronics to achieve their performance levels and versatility. The advantages and disadvantages of FPS vidicons and of antimony trisulfide and silicon target materials in such applications are discussed in detail. All of the electronics circuits are discussed. The sweep generator designs are treated at length because they are the key to the cameras' versatility. Emphasis is placed on remotely controllable analog and digital sweep generators. The latter is a complete CAMAC-compatible subsystem containing a 16-function master arithmetic logic unit. Pulsed and cw methods of obtaining transfer characteristics are described and compared. The effects of generation rates, tube types, and target types on the resolution, determined from contrast-transfer-function curves, are discussed. Several applications are described, including neutron TV pinhole, TREAT, and barium-release experiments.
Date: June 1, 1980
Creator: Noel, B.W. & Yates, G.J.
Partner: UNT Libraries Government Documents Department

Sensor Development for the Large Synoptic Survey Telescope.

Description: The Large Synoptic Survey project proposes to build an 8m-class ground-based telescope with a dedicated wide field camera. The camera consists of a large focal plane mosaic composed of multi-output CCDs with extended red response. Design considerations and preliminary characterization results for the sensors are presented in this contribution to the Workshop.
Date: June 7, 2007
Creator: O'Connor,P.; Radeka, V. & Takacs, P.
Partner: UNT Libraries Government Documents Department

The rest-frame K-band luminosity function of galaxies in clusters to z = 1.3

Description: We derive the rest-frame K-band luminosity function for galaxies in 32 clusters at 0.6 &lt; z &lt; 1.3 using deep 3.6 {micro}m and 4.5 {micro}m imaging from the Spitzer Space Telescope InfraRed Array Camera (IRAC). The luminosity functions approximate the stellar mass function of the cluster galaxies. Their dependence on redshift indicates that massive cluster galaxies (to the characteristic luminosity M*{sub K}) are fully assembled at least at z {approx} 1.3 and that little significant accretion takes place at later times. The existence of massive, highly evolved galaxies at these epochs is likely to represent a significant challenge to theories of hierarchical structure formation where such objects are formed by the late accretion of spheroidal systems at z &lt; 1.
Date: March 20, 2007
Creator: De Propris, R; Stanford, S A; Eisenhardt, P R; Holden, B P & Rosati, P
Partner: UNT Libraries Government Documents Department

New approach to jitter reduction of an x-ray streak camera in accumulation mode.

Description: An x-ray streak camera operating in accumulation mode was developed for studying ultrafast dynamics at synchrotron facilities. A laser-triggered photoconductive switch was used as a sweeping unit to obtain low timing jitter. The fast rise time of the ramp pulse generated by the switch (90 ps) combined with the fast response of the traveling wave deflection plates (150 ps) significantly reduced the jitter caused by the shot-to-shot laser fluctuation. At {approx}1% rms (root mean square) laser energy fluctuation, the resolution of the camera is 1.1 ps when over 5000 laser shots were accumulated. This is two times better than that of the previous design with slower response (300 ps) deflection plates.
Date: July 19, 2002
Creator: Liu, J.; MacPhee, A. G.; Liu, C.; Shan, B.; Wang, J. & Chang, Z.
Partner: UNT Libraries Government Documents Department


Description: A prototype liquid xenon {gamma}-camera has been constructed and preliminary results obtained. The sensitive volume is 7 c x 7 cm in area and 1.5 cm thick. Orthogonal coordinates for each interacting {gamma}-ray are provided by 24 anode wires 5 {micro} in diameter spaced 2.8 mm apart and 24 cathode strips.
Date: December 1, 1972
Creator: Zaklad, Haim; Derenzo, Stephen E.; Muller, Richard A. & Smits,Robert G.
Partner: UNT Libraries Government Documents Department

A New Determination of the High Redshift Type Ia Supernova Rateswith the Hubble Space Telescope Advanced Camera for Surveys

Description: We present a new measurement of the volumetric rate of Type Ia supernova up to a redshift of 1.7, using the Hubble Space Telescope (HST) GOODS data combined with an additional HST dataset covering the North GOODS field collected in 2004. We employ a novel technique that does not require spectroscopic data for identifying Type Ia supernovae (although spectroscopic measurements of redshifts are used for over half the sample); instead we employ a Bayesian approach using only photometric data to calculate the probability that an object is a Type Ia supernova. This Bayesian technique can easily be modified to incorporate improved priors on supernova properties, and it is well-suited for future high-statistics supernovae searches in which spectroscopic follow up of all candidates will be impractical. Here, the method is validated on both ground- and space-based supernova data having some spectroscopic follow up. We combine our volumetric rate measurements with low redshift supernova data, and fit to a number of possible models for the evolution of the Type Ia supernova rate as a function of redshift. The data do not distinguish between a flat rate at redshift &gt; 0.5 and a previously proposed model, in which the Type Ia rate peaks at redshift {approx} 1 due to a significant delay from star-formation to the supernova explosion. Except for the highest redshifts, where the signal to noise ratio is generally too low to apply this technique, this approach yields smaller or comparable uncertainties than previous work.
Date: October 1, 2007
Creator: Kuznetsova, N.; Barbary, K.; Connolly, B.; Kim, A.G.; Pain, R.; Roe, N.A. et al.
Partner: UNT Libraries Government Documents Department

Tower Camera Handbook

Description: The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.
Date: January 1, 2005
Creator: Moudry, D
Partner: UNT Libraries Government Documents Department

Circumnuclear Star Clusters in the Galaxy Merger NGC 6240, Observed with Keck Adaptive Optics and HST

Description: We discuss images of the central {approx} 10 kpc (in projection) of the galaxy merger NGC 6240 at H and K{prime} bands, taken with the NIRC2 narrow camera on Keck II using natural guide star adaptive optics. We detect 28 star clusters in the NIRC2 images, of which only 7 can be seen in the similar-spatial-resolution, archival WFPC2 Planetary Camera data at either B or I bands. Combining the NIRC2 narrow camera pointings with wider NICMOS NIC2 images taken with the F110W, F160W, and F222M filters, we identify a total of 32 clusters that are detected in at least one of these 5 infrared ({lambda}{sub c} &gt; 1 {micro}m) bandpasses. By comparing to instantaneous burst, stellar population synthesis models (Bruzual & Charlot 2003), we estimate that most of the clusters are consistent with being {approx} 15 Myr old and have photometric masses ranging from 7 x 10{sup 5} M{sub {circle_dot}} to 4 x 10{sup 7}M{sub {circle_dot}}. The total contribution to the star formation rate (SFR) from these clusters is approximately 10M{sub {circle_dot}} yr{sup -1}, or {approx} 10% of the total SFR in the nuclear region. We use these newly discovered clusters to estimate the extinction toward NGC 6240's double nuclei, and find values of A{sub v} as high as 14 magnitudes along some sightlines, with an average extinction of A{sub v} {approx} 7 mag toward sightlines within {approx} 3-inches of the double nuclei.
Date: February 12, 2007
Creator: Pollack, L K; Max, C E & Schneider, G
Partner: UNT Libraries Government Documents Department

3w Transmitted Beam Diagnostic at the Omega Laser Facility

Description: A 3{omega} transmitted beam diagnostic has been commissioned on the Omega Laser at the Laboratory for Laser Energetics, University of Rochester [Soures et.al., Laser Part. Beams 11 (1993)]. Transmitted light from one beam is collected by a large focusing mirror and directed onto a diagnostic platform. The near field of the transmitted light is imaged; the system collects information from twice the original f-cone of the beam. Two gated optical cameras capture the near field image of the transmitted light. Thirteen spatial positions around the measurement region are temporally resolved using fast photodiodes to allow a measure of the beam spray evolution. The Forward stimulated Raman scattering and forward simulated Brillion scattering are spectrally and temporally resolved at 5 independent locations within twice the original f-cone. The total transmitted energy is measured in two spectral bands ({delta}{lambda} &lt; 400 nm and {delta}{lambda} &gt; 400 nm).
Date: April 24, 2006
Creator: Froula, D H; Rekow, V; Sorce, C; Piston, K; Knight, R; Alvarez, S et al.
Partner: UNT Libraries Government Documents Department

Radio-loud high-redshift protogalaxy canidates in Bootes

Description: We used the Near Infrared Camera (NIRC) on Keck I to obtain K{sub s}-band images of four candidate high-redshift radio galaxies selected using optical and radio data in the NOAO Deep Wide-Field Survey in Bootes. Our targets have 1.4 GHz radio flux densities greater than 1 mJy, but are undetected in the optical. Spectral energy distribution fitting suggests that three of these objects are at z &gt; 3, with radio luminosities near the FR-I/FR-II break. The other has photometric redshift z{sub phot} = 1.2, but may in fact be at higher redshift. Two of the four objects exhibit diffuse morphologies in K{sub s}-band, suggesting that they are still in the process of forming.
Date: July 20, 2007
Creator: Croft, S; van Breugel, W; Brown, M J; de Vries, W; Dey, A; Eisenhardt, P et al.
Partner: UNT Libraries Government Documents Department

SI PC104 Performance Test Report

Description: The Spectral Instruments (SI) PC104 systems associated with the SI-1000 CCD camera exhibited intermittent power problems during setup, test and operations which called for further evaluation and testing. The SI PC104 System is the interface between the SI-1000 CCD camera and its associated Diagnostic Controller (DC). As such, the SI PC104 must be a reliable, robust system capable of providing consistent performance in various configurations and operating conditions. This SI PC104 system consists of a stackable set of modules designed to meet the PC104+ Industry Standard. The SI PC104 System consists of a CPU module, SI Camera card, Media converter card, Video card and a I/O module. The root cause of power problems was identified as failing solder joints at the LEMO power connector attached to the SI Camera Card. The recommended solution was to provide power to the PC104 system via a PC104+ power supply module configured into the PC104 stack instead of thru the LEMO power connector. Test plans (2) were developed to test SI PC104 performance and identify any outstanding issues noted during extended operations. Test Plan 1 included performance and image acquisition tests. Test Plan 2 verified performance after implementing recommendations. Test Plan 2 also included verifying integrity of system files and driver installation after bootup. Each test plan was implemented to fully test against each set of problems noted. Test Plan presentations and Test Plan results are attached as appendices. Anticipated test results will show successful operation and reliable performance of the SI PC104 system receiving its power via a PC104 power supply module. A SI PC104 Usage Recommendation Memo will be sent out to the SI PC104 User Community. Recommendation memo(s) are attached as appendices.
Date: December 16, 2005
Creator: Montelongo, S
Partner: UNT Libraries Government Documents Department