71 results on '"Gerard A. Luppino"'
Search Results
52. Detection of weak lensing by a cluster of galaxies at z=0.83
- Author
-
Gerard Anthony Luppino and Nick Kaiser
- Subjects
Physics ,Astrophysics (astro-ph) ,FOS: Physical sciences ,Astronomy and Astrophysics ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Redshift ,Galaxy ,Distribution (mathematics) ,Space and Planetary Science ,Magnitude (astronomy) ,Cluster (physics) ,Galaxy cluster ,Weak gravitational lensing ,Astrophysics::Galaxy Astrophysics - Abstract
We report the detection of weak gravitational lensing of faint, distant background galaxies by the rich, X-ray luminous cluster of galaxies MS1054-03 at z=0.83. This is the first measurement of weak lensing by a bona fide cluster at such a high redshift. We detect tangential shear at the 5% - 10% level over a range of radii 50'' < r < 250'' centered on the optical position of the cluster. Two-dimensional mass reconstruction using galaxies with 21.5 < I < 25.5 shows a strong peak which coincides with the peak of the smoothed cluster light distribution. Splitting this sample by magnitude (at I = 23.5) and color (at R-I = 0.7), we find that the brighter and redder subsamples are only very weakly distorted, indicating that the faint blue galaxies (FBG's), which dominate the shear signal, are relatively more distant. The derived cluster mass is quite sensitive to the N(z) for the FBG's. At one extreme, if all the FBG's are at z_s = 3, then the mass within a $0.5h^{-1}$Mpc aperture is $(5.9 \pm 1.24)\times 10^{14}$\h1 $M_\odot$, and the mass-to-light ratio is $M/L_V = 350 \pm 70 h$ in solar units. For $z_s = 1.5$ the derived mass is $\sim$70\% higher and $M/L \simeq 580 h$. If $N(z)$ follows the no evolution model (in shape) then $M/L \simeq 800h$, and if all the FBG's lie at $z_s\la 1$ the required $M/L$ exceeds $1600h$. These data provide clear evidence that large, dense mass concentrations existed at early epochs; that they can be weighed efficiently by weak lensing observations; and that most of the FBG's are at high redshift., Submitted to ApJ, 15 pages (incl 8 figs, 3 of which are plates). Plate images not included, but are available from ftp://hubble.ifa.hawaii.edu/pub/ger/ms1054/ms1054_fig[1,3,5].ps.Z
- Published
- 1996
53. MegaCam: a wide-field optical/infrared camera for the UH 2.2-m telescope
- Author
-
Gerard Anthony Luppino, Klaus-Werner Hodapp, and Joseph L. Hora
- Subjects
Physics ,Pixel ,business.industry ,Optical engineering ,Magnification ,Field of view ,law.invention ,Telescope ,chemistry.chemical_compound ,Optics ,chemistry ,Angle of incidence (optics) ,law ,Optoelectronics ,Mercury cadmium telluride ,business ,Beam splitter - Abstract
The MegaCam is a multi-purpose, wide-field, two-color camera being designed for use at the UH 2.2m telescope. The camera will utilize a Rockwell 1024 x 1024 HgCdTe detector array for 1-2.5 micrometers imaging, and a 2048 x 4096 frame-store CCD (2048 x 2048 active area) for optical imaging. The optics are based on a modified Offner relay design with additional lenses to give a 2:1 magnification in the infrared channel for a field of view of 5'.8 x 5'.8 (0.34 arcsec/pixel) using the f/10 telescope secondary, or a scale of 1'.9 x 1'.9 (0.15 arcsec/pixel) at f/31. This design provides a simple, high-throughput, and compact optical layout. A beamsplitter is placed in front of the IR optics at a low angle of incidence to form the optical image at 1:1 magnification on the CCD, for a field of view of 4'.7 x 4'.7 and 1'.5 x 1'.5 at f/10 and f/31, respectively. The optics and filters are to be housed in a LN2-cooled dewar. The CCD and IR arrays will be operated with modified SDSU-design controllers. The user interface will have several modes to make simultaneous optical/IR imaging simple to configure and perform at the telescope.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
- Published
- 1994
54. Design of an 8192x8192 pixel CCD mosaic
- Author
-
Gerard Anthony Luppino, John C. Geary, and Richard A. Bredthauer
- Subjects
Physics ,Optics ,Distance measurement ,Mauna kea ,Sampling (signal processing) ,Pixel ,Galactic astronomy ,Observatory ,business.industry ,Field of view ,Mosaic (geodemography) ,business ,Remote sensing - Abstract
We describe the design of an ultra-format, 8192 x 8192 pixel CCD mosaic imager under construction for the Mauna Kea Observatory. The mosaic will be built from a 4 x 2 array of 3-edge-buttable 2048 x 4096 15 micrometers pixel CCDs fabricated by Loral Fairchild. We outline the scientific justification for such a mosaic and the technical details of the 3-edge-buttable 2048 x 4096 CCD design. We also present our strategy for imager packaging and subsequent mosaic construction which will result in a mosaic with individual elements that can easily be installed and removed. This particular CCD mosaic is intended for two existing MKO telescopes: the UH 2.2 m and the CFHT 3.6m. In either configuration, the imager will offer an enormous field of view with excellent spatial sampling.
- Published
- 1994
55. UH/IfA fast tip-tilt secondary
- Author
-
Gerard Anthony Luppino, Tony T. Young, Wesley Nakamura, Malcolm J. Northcott, Claude Roddier, Kevin T. C. Jim, J. Elon Graves, Andrew J. Pickles, Timothy J. Keller, Lennox L. Cowie, Hubert Yamada, Richard J. Wainscoat, Charles P. Cavedoni, and Alan Stockton
- Subjects
Telescope ,Engineering ,Tilt (optics) ,Mauna kea ,business.industry ,Image quality ,law ,Optical engineering ,business ,Adaptive optics ,Simulation ,Remote sensing ,law.invention - Abstract
A fast tip-tilt secondary is being implemented on the University of Hawaii 2.2-m telescope, to provide image quality to match the site characteristics of Mauna Kea, and complement the existing wide-field RC secondary.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
- Published
- 1994
56. New circular radial-scan frame-storage CCDs for low-order adaptive optics wavefront curvature sensing
- Author
-
Gerard Anthony Luppino and John C. Geary
- Subjects
Physics ,Wavefront ,Optics ,Series (mathematics) ,business.industry ,Computer data storage ,Frame (networking) ,Wavefront sensor ,business ,Adaptive optics ,Deformable mirror ,Symmetry (physics) - Abstract
CCDs having circular rather than rectilinear symmetry offer some advantages for low-order wavefront sensing. A series of imagers having 24 sectors and 12 radial zones (plus frame store) has been developed. Three different output structures have been utilized in order to investigate low-noise operational limits.
- Published
- 1994
57. HUBBLE SPACE TELESCOPEIMAGING OF Lyα EMISSION ATz≈ 4.4
- Author
-
Donald N. B. Hall, Rogier A. Windhorst, James E. Rhoads, Joseph Silk, Jay Anderson, Randy A. Kimble, Steven L. Finkelstein, Alistair R. Walker, Anton M. Koekemoer, Michael John Disney, Jay A. Frogel, Robert W. O'Connell, Nimish P. Hathi, Howard E. Bond, John T. Trauger, Bruce Balick, Norman A. Grogin, Seth H. Cohen, Bradley C. Whitmore, Gerard Anthony Luppino, Francesco Paresce, Keely D. Finkelstein, Jon A. Holtzman, Max Mutchler, Patrick J. McCarthy, Michael A. Dopita, Erick T. Young, Daniela Calzetti, Russell E. Ryan, Sangeeta Malhotra, and Abhijit Saha
- Subjects
Physics ,Photon ,010308 nuclear & particles physics ,Astrophysics::High Energy Astrophysical Phenomena ,Astronomy ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,medicine.disease_cause ,01 natural sciences ,Galaxy ,Redshift ,Space and Planetary Science ,0103 physical sciences ,Radiative transfer ,medicine ,Halo ,Alpha decay ,010303 astronomy & astrophysics ,Wide Field Camera 3 ,Astrophysics::Galaxy Astrophysics ,Ultraviolet - Abstract
We present the highest redshift detections of resolved Lyman alpha emission, using Hubble Space Telescope/ACS F658N narrowband-imaging data taken in parallel with the Wide Field Camera 3 Early Release Science program in the GOODS CDF-S. We detect Lyman alpha emission from three spectroscopically confirmed z = 4.4 Lyman alpha emitting galaxies (LAEs), more than doubling the sample of LAEs with resolved Lyman alpha emission. Comparing the light distribution between the rest-frame ultraviolet continuum and narrowband images, we investigate the escape of Lyman alpha photons at high redshift. While our data do not support a positional offset between the Lyman alpha and rest-frame ultraviolet (UV) continuum emission, the half-light radii in two out of the three galaxies are significantly larger in Lyman alpha than in the rest-frame UV continuum. This result is confirmed when comparing object sizes in a stack of all objects in both bands. Additionally, the narrowband flux detected with HST is significantly less than observed in similar filters from the ground. These results together imply that the Lyman alpha emission is not strictly confined to its indigenous star-forming regions. Rather, the Lyman alpha emission is more extended, with the missing HST flux likely existing in a diffuse outer halo. This suggests that the radiative transfer of Lyman alpha photons in high-redshift LAEs is complicated, with the interstellar-medium geometry and/or outflows playing a significant role in galaxies at these redshifts.
- Published
- 2011
58. Curvature-based adaptive optics instrument for the UH 2.2-m telescope
- Author
-
Gerard Anthony Luppino, Malcolm J. Northcott, Timothy J. Keller, Alan T. Tokunaga, Kevin T. C. Jim, Andrew J. Pickles, and J. Elon Graves
- Subjects
Flexibility (engineering) ,Engineering ,business.industry ,Curvature ,law.invention ,Telescope ,Signal-to-noise ratio ,law ,visual_art ,Electronic component ,visual_art.visual_art_medium ,Electronic engineering ,Cost constraint ,Focus (optics) ,business ,Adaptive optics - Abstract
This paper describes a low cost adaptive optics (AO) instrument that is being built for the f/31 focus of the UH 2.2m telescope. While operating within the low cost constraint, we have tried to maximize the flexibility and usefulness of the instrument, and minimize the impact of the necessary performance compromises. We have used off-the-shelf optical and electronic components wherever possible, and have emphasized simplicity of design throughout the instrument. The UH prototype AO system, on which the 2.2m AO system is based, is described elsewhere, thus the principles of operation of the UH 2.2m instrument will not be described in detail here.
- Published
- 1993
59. Astronomical CCD mosaics: first results with the University of Hawaii 4096 x 4096 pixel CCD camera system
- Author
-
Robert J. Hlivak, Hubert Yamada, Gerard A. Luppino, and Kevin T. C. Jim
- Subjects
Physics ,Pixel ,Workstation ,business.industry ,Controller (computing) ,Serial port ,Die (integrated circuit) ,law.invention ,Telescope ,Cardinal point ,Optics ,law ,Computer graphics (images) ,business ,Digital signal processing - Abstract
We present the first results from the University of Hawaii Institute for Astronomy project to develop largeformat optical CCD mosaics for the telescopes on Manna Kea. We have constructed two 4096 x 4096 mosaics: both are 2 x 2 arrays of 2-edge abuttable 2048 x 2048 15tm pixel imagers built by Loral Aeronutronics. The first mosaic is constructed using an abuttable package design yielding an array that can be assembled and disassembled using the bestavailable separatelytested quadrants. The second mosaic is formed by packaging a monolithic quad die consisting of four functioning 2048 x 2048 devices from a single wafer. In addition to the mechanical design of the focal plane and dewar we describe the system used to operate the CCDs including the programmable DSP-based CCD controller and our high-speed serial interface into the DSP port of a NeXT computer workstation. We present our initial x-ray and optical test results from the " monolithic mosaic" and our first data from the telescope. 1
- Published
- 1992
60. 4096 x 4096 pixel CCD mosaic imager for astronomical applications
- Author
-
John C. Geary, Richard Bredthauer, Gerard Anthony Luppino, Robert J. Hlivak, and Lloyd B. Robinson
- Subjects
Engineering ,Optics ,Pixel ,business.industry ,Package design ,Solid-state ,Wafer ,business - Abstract
A large-format CCD imager to be used in a 2 X 2 mosaic array has been designed and fabricated. Each quadrant is an independent imager of 2048 X 2048 15 micrometers pixels, designed to be edge-butted on two sides. After sawing and mounting the individual dice in custom, buttable packages, the authors assembled a 4096 X 4096 mosaic array measuring more than 61 mm on a side with just 400 microns dead space between imaging areas. With this buttable package design, each quadrant of the mosaic can be separately tested, optimized, and, if necessary, replaced. Also described are smaller 2688 X 512 15 micrometers pixel CCD imagers designed for spectrographic applications that were fabricated using space in the chords of the same 100 mm silicon wafer containing the 2048 X 2048 edge-buttable devices.
- Published
- 1991
61. Infrared Surface Brightness Fluctuations in Virgo Cluster Elliptical Galaxies
- Author
-
Gerard A. Luppino, Joseph B. Jensen, and John L. Tonry
- Subjects
Physics ,Luminous infrared galaxy ,Space and Planetary Science ,Surface brightness fluctuation ,Elliptical galaxy ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Surface brightness ,Brightest cluster galaxy ,Fundamental plane (elliptical galaxies) ,Virgo Cluster ,Galaxy cluster - Published
- 1996
62. Infrared surface brightness fluctuations - K-prime-band observations of M31, M32, and the distance to Maffei 1
- Author
-
Gerard A. Luppino and John L. Tonry
- Subjects
Absolute magnitude ,Physics ,Luminous infrared galaxy ,Infrared astronomy ,Space and Planetary Science ,K band ,Elliptical galaxy ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Surface brightness ,Lenticular galaxy ,Galaxy - Abstract
We have taken 2.1 μm infrared K'-band images of the Local Group galaxies M31 and M32 and the nearby elliptical galaxy Maffei 1 using a 256×256 pixel HgCdTe infrared array. Measurement of the amplitude of the K'-band surface brightness fluctuations (SBFs) for M31 has enabled us to calibrate the K'-band fluctuations absolute magnitude, M K' =-5.61±0.09, taking M31 to be 0.77 Mpc distant. This agrees with theoretical predictions
- Published
- 1993
63. Infrared imaging of MG 0414 + 0534 - The red gravitational lens systems as lensed radio galaxies
- Author
-
Gerard A. Luppino and James Annis
- Subjects
Physics ,Luminous infrared galaxy ,Infrared ,Radio galaxy ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Ir image ,law.invention ,Lens (optics) ,Photometry (astronomy) ,Gravitational lens ,X-shaped radio galaxy ,Space and Planetary Science ,law - Abstract
We present an IR image of the gravitational lens system MG 0414 + 0534, and IR photometry of PG 1115 + 080, H1413 + 117, and Q1429 - 008. The IR of MG 0414 + 0534 shows a morphology that is similar to the radio and optical morphologies. The object is bright (K-prime = 13.7) and extremely red (I-K-prime = 5.7). MG 0414 + 0534 thus becomes the second radio-selected lens system to have very red optical IR colors. When plotted on a color-magnitude diagram of objects from a radio survey, MG 0414 + 0534 and the other very red system, MG 1131 + 0456, lie near the locus of radio galaxies. We therefore suggest that these systems are lensed high-redshift radio galaxies. In general, lensed radio galaxies should be common among lens systems selected from radio surveys, since a high proportion of radio sources are radio galaxies.
- Published
- 1993
64. C1 1358 + 6245 at Z = 0.32 - an X-ray selected, distant, rich cluster of galaxies
- Author
-
Gerard A. Luppino, George R. Ricker, Ian M. McHardy, and Brin A. Cooke
- Subjects
Luminous infrared galaxy ,Physics ,Velocity dispersion ,Astronomy ,Astronomy and Astrophysics ,Type-cD galaxy ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Abell 2744 ,Space and Planetary Science ,Galaxy group ,Astrophysics::Solar and Stellar Astrophysics ,Brightest cluster galaxy ,Lenticular galaxy ,Astrophysics::Galaxy Astrophysics ,Galaxy cluster - Abstract
BVRI CCD photometric observations of an extremely rich, X-ray selected cluster of galaxies, Cl 1358+6245, are presented. Spectroscopy of the optically dominant cluster galaxy indicate a redshift of z = 0.32 for the cluster. The photometric catalog contains 322 galaxies measured in at least two colors detected in the CCD field. The cluster luminosity function and color-magnitude diagrams are included. Cl 1358+6245 is extremely rich, contains a compact, concentrated core of galaxies, exhibits the Butcher-Oemler effect with a blue galaxy fraction 0.10 < f b < 0.18, and is X-ray luminous
- Published
- 1991
65. Erratum: 'Observations of Luminosity Fluctuations in Virgo' [AJ, 100, 1416 (1990)]
- Author
-
Edward A. Ajhar, Gerard A. Luppino, and John L. Tonry
- Subjects
Physics ,Space and Planetary Science ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Luminosity - Published
- 1991
66. Observations of surface-brightness fluctuations in Virgo
- Author
-
Edward A. Ajhar, John L. Tonry, and Gerard A. Luppino
- Subjects
Physics ,Space and Planetary Science ,Star formation ,Surface brightness fluctuation ,Metallicity ,Astronomy ,Astronomy and Astrophysics ,Astrophysics ,Astrometry ,Surface brightness ,Virgo Cluster ,Galaxy ,Luminosity - Abstract
VRI photometric observations of surface-brightness fluctuation in 13 Virgo Cluster galaxies, M32, and NGC 3379, obtained using an 800 x 800 CCD array on the 4-m telescope at KPNO during March 1989, are reported. The data-reduction techniques are described in detail, and the results are presented in tables and graphs. Particular attention is given to distance estimates derived from the I-band fluctuations: it is shown that NGC 4365 is behind the cluster, while NGC 4468 and NGC 4489 are in the foreground. The average distance to the cluster is found to be 17 + or - 1 Mpc, with H0 = 78 + or - 6 km/sec Mpc; the corresponding values from a direct isochrone calibration are 21 Mpc and 64 + or - 5 km/sec Mpc.
- Published
- 1990
67. X-Ray CCD Cameras: I. Design of Low Noise, High Performance Systems
- Author
-
Gerard A. Luppino, George R. Ricker, and John P. Doty
- Subjects
Physics ,Noise ,Optics ,Ccd camera ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,business ,Low noise - Abstract
In general, attention to a multitude of details is essential when designing low noise CCD cameras. This paper describes some of the critical details of the MIT X-ray CCD camera design. Special attention is given to those portions of the system which are different from conventional practice in the design of CCD cameras. Furthermore, an attempt has been made to generalize the design so that both optical and X-ray requirements can be satisfied wherever possible. Currently, noise levels of
- Published
- 1987
68. Imaging And Nondispersive Spectroscopy Of Soft X Rays Using A Laboratory X-Ray Charge-Coupled-Device System
- Author
-
John P. Doty, Natale M. Ceglio, George R. Ricker, Gerard A. Luppino, and John V. Vallerga
- Subjects
Physics ,X-ray spectroscopy ,Spectrometer ,business.industry ,General Engineering ,X-ray detector ,Atomic and Molecular Physics, and Optics ,Imaging spectroscopy ,Optics ,Charge-coupled device ,Image sensor ,business ,Spectroscopy ,Image resolution - Abstract
This paper describes the design and performance of a laboratory instrument for imaging and nondispersive spectroscopy of soft X-rays (300 eV to 10 keV) utilizing a virtual-phase CCD. This instrument has achieved a spatial resolution of 22 microns (limited by pixel size) with an overall array area of 584 x 390 pixels. It has achieved an energy resolution of about 140 eV FWHM for single-pixel Fe-55 X-ray events (5.9 keV) with the CCD operated at -30 C. The CCD has been operated in photon-counting mode at room temperature, and X-ray spectra with an energy resolution of about 450 eV at 5.9 keV have been obtained. The low energy X-ray sensitivity of the CCD also has been demonstrated by detecting carbon K-alpha X-rays (277eV).
- Published
- 1987
69. Design Of Low Noise, High Performance X-Ray Charge-Coupled-Device Cameras
- Author
-
George R. Ricker, Gerard A. Luppino, and John P. Doty
- Subjects
Physics ,Signal processing ,Spectrometer ,Preamplifier ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,General Engineering ,X-ray optics ,Electron ,Noise (electronics) ,Atomic and Molecular Physics, and Optics ,Particle detector ,Optics ,Charge-coupled device ,business - Abstract
This paper describes some of the critical details of the MIT X-ray CCD camera design. Special attention is given to those portions of the system that deviate from conventional practice in the design of CCD cameras. Furthermore, an attempt has been made to generalize the design so that both optical and X-ray requirements can be satisfied whenever possible. Currently, noise levels of less than 8 electrons rms are routinely achieved with this design, and even lower levels (less than 5 electrons) should be realizable.
- Published
- 1987
70. X-Ray CCD Cameras II: A Versatile Laboratory System
- Author
-
George R. Ricker, Gerard A. Luppino, Natale M. Ceglio, John P. Doty, and John V. Vallerga
- Subjects
Physics ,Photon ,Optics ,business.industry ,Detector ,Resolution (electron density) ,X-ray detector ,X-ray ,Optoelectronics ,business ,Spectroscopy ,Image resolution ,Photon counting - Abstract
The use of charge-coupled devices (CCDs) as single photon X-ray detectors has been documented by several research groups. In this paper we describe the design and performance of a powerful laboratory instrument for imaging and non-dispersive spectroscopy of soft X-rays (200 eV to 10 keV) utilizing Texas Instruments TI-4849 virtual-phase CCDs. With this instrument we have achieved a spatial resolution of 22 microns (limited by pixel size) with an overall array area of 584x390 pixels.We have achieved an energy-resolution of -140 eV FWHM for single-pixel Fe55 X-ray events (5.9 keV) with the CCD operated at only -30°C. We have operated the CCD in photon-counting mode at room-temperature and have obtained X-ray spectra with an energy resolution of -450 eV at 5.9 keV. We also have demonstrated the low-energy X-ray sensitivity of the CCD by detecting Carbon K-alpha X-rays (277 eV).
- Published
- 1987
71. Surface brightness fluctuations and the distance to the Virgo Cluster
- Author
-
John L. Tonry, Gerard A. Luppino, and Edward A. Ajhar
- Subjects
Physics ,Astrophysics::High Energy Astrophysical Phenomena ,Surface brightness fluctuation ,Astronomy ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Virgo Cluster ,Galaxy ,Space and Planetary Science ,Elliptical galaxy ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Brightest cluster galaxy ,Astrophysics::Galaxy Astrophysics ,Galaxy cluster ,Dwarf galaxy ,Luminosity function (astronomy) - Abstract
Preliminary results from a project to measure the fluxes of giant stars in M32, NGC 3379, and five Virgo Cluster galaxies are presented. Since the Virgo Cluster galaxies are approximately equidistant, variations in observed fluctuation amplitude from galaxy to galaxy can be ascribed to variations in absolute luminosity of the giant stars in the galaxies. Assuming a distance of 0.72 Mpc for M32 and correcting for the color effect in m-bar, the typical brightness of giant stars, distances of 9 Mpc for NGC 3379 and 14 Mpc for Virgo, accurate to about 10 percent, are derived. This is used to find a Hubble constant of 88 km/s/Mpc. The method can be used to measure m-bar in galaxies at least 40-50 Mpc distant.
- Published
- 1989
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.