Cosmic Gravitational Shear from the HST Medium Deep Survey (2003)
Casertano, Stefano, Ratnatunga, Kavan U., Griffiths, Richard E.
We present a measurement of cosmic shear on scales ranging from $ 10\arcsec $ to $ 2\arcmin $ in 347 WFPC2 images of random fields. Our result is based on shapes measured via image fitting and on a...
Investigation of Gravitational Lens Mass Models (2001)
Knudson, Adam, Ratnatunga, Kavan U., Griffith, Richard E.
We have previously reported the discovery of strong gravitational lensing by faint elliptical galaxies using the WFPC2 on HST and here we investigate their potential usefulness in putting constraints...
Disk and Bulge Morphology of WFPC2 galaxies: The HST Medium Deep Survey database (1999)
Ratnatunga, Kavan U., Griffiths, Richard E., Ostrander, Eric J.
Quantitative morphological and structural parameters are estimated for galaxies detected in HST observations of WFPC2 survey fields. A modeling approach based on maximum likelihood has been developed...
Tyson, J. Anthony, Fischer, Philippe, Guhathakurta, Puragra, McIlroy, Peter, Wenk, R. A., Huchra, John P., ...
Deep Hubble Space Telescope Wide Field Camera (WFC-1) imaging of a region 3farcm7 east of the V = 13 mag Seyfert galaxy NGC 5548 in the F555W and F785LP bands, and deep ground-based V and I imaging,...
Tyson, J. Anthony, Fischer, Philippe, Guhathakurta, Puragra, McIlroy, Peter, Wenk, R. A., Huchra, John P., ...
Deep Hubble Space Telescope Wide Field Camera (WFC-1) imaging of a region 3farcm7 east of the V = 13 mag Seyfert galaxy NGC 5548 in the F555W and F785LP bands, and deep ground-based V and I imaging,...
The HST Medium Deep Survey: progress towards resolution of the faint blue galaxy problem (1997)
Griffiths, Richard, Ratnatunga, Kavan U., Casertano, Stefano, Im, Myungshin, Neuschaefer, Lyman W., Ostrander, Eric J., ...
WFPC2 on HST has provided the means to make rapid progress towards solving a long-standing problem in observational cosmology, viz. the nature of the objects contributing to the faint blue galaxy...
The HST Medium Deep Survey: progress towards resolution of the faint blue galaxy problem (1997)
Griffiths, Richard, Ratnatunga, Kavan U., Casertano, Stefano, Im, Myungshin, Neuschaefer, Lyman W., Ostrander, Eric J., ...
WFPC2 on HST has provided the means to make rapid progress towards solving a long-standing problem in observational cosmology, viz. the nature of the objects contributing to the faint blue galaxy...
Im, Myungshin, Griffiths, Richard E., Ratnatunga, Kavan U.
We have identified seven (field) elliptical galaxies acting as strong gravitational lenses and have used them to measure cosmological parameters. To find the most likely value for Omega_m (=...
Compact Nuclei in Moderately Redshifted Galaxies (1996)
Sarajedini, Vicki L., Green, Richard F., Griffiths, Richard E., Ratnatunga, Kavan U.
The Hubble Space Telescope WFPC2 is being used to obtain high-resolution images in the V and I bands for several thousand distant galaxies as part of the Medium Deep Survey (MDS). An important...
Luminosity Functions of Elliptical Galaxies at z < 1.2 (1996)
Im, Myungshin, Griffiths, Richard E., Ratnatunga, Kavan U., Sarajedini, Vicki L.
The luminosity functions of E/S0 galaxies are constructed in 3 different redshift bins (0.2 < z < 0.55, 0.55 < z < 0.8, 0.8 < z < 1.2), using the data from the Hubble Space Telescope Medium Deep...
Driver, Simon P., Windhorst, Rogier A., Ostrander, Eric J., Keel, William C., Griffiths, Richard E., Ratnatunga, Kavan U.
We determine the morphological mix of field galaxies down to $m_{I}\simeq 24.25$ mag ($m_{B}\sim 26.0$ mag) from a single ultradeep HST WFPC2 image in both the $V_{606}$ and $I_{814}$ filters. In...
New "Einstein Cross" Gravitational Lens Candidates in HST WFPC2 Survey Images (1995)
Ratnatunga, Kavan U., Ostrander, Eric J., Griffiths, Richard E., Im, Myungshin
We report the serendipitous discovery of ``Einstein cross'' gravitational lens candidates using the Hubble Space Telescope. We have so far discovered two good examples of such lenses, each in the...
The theta-z relation for HST bulges and disks out to z similar or equal to 0.8 (1994)
Mutz, Steven B., Windhorst, Rogier A., Schmidtke, Paul C., Pascarelle, Sebastian M., Griffiths, Richard E., Ratnatunga, Kavan U., ...
We present HST scale lengths and ground-based redshifts for 63 faint field galaxies down to 1 ≲ 21.5 mag from the Medium-Deep Survey. These have measured redshifts z ≲ 0.8 and half-light...
The morphology of faint galaxies in medium deep survey images using WFPC2 (1994)
Griffiths, Richard, Casertano, Stefano, Ratnatunga, Kavan U., Neuschaefer, Lyman W., Ellis, Richard S., Gilmore, Gerard F., ...
First results from HST Medium Deep Survey images taken with WFPC2 demonstrate that galaxy classifications can be reliably performed to magnitudes I814 less-than-or-similar-to 22.0 in the F815W band....
Windhorst, Rogier A., Schmidtke, Paul C., Pascarelle, Sebastian M., Gordon, J. M., Griffiths, Richard, Ratnatunga, Kavan U., ...
We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medium Deep Survey (MDS). These have redshifts in the range...
Griffiths, Richard, Ratnatunga, Kavan U., Neuschaefer, Lyman W., Casertano, Stefano, Im, Myungshin, Wyckoff, Eric W., ...
We present results from the Medium Deep Survey (MDS), a Key Project using the Hubble Space Telescope. Wide Field Camera images of random fields have been taken in "parallel mode" with an effective...
The theta-z relation for HST bulges and disks out to z similar or equal to 0.8 (1994)
Mutz, Steven B., Windhorst, Rogier A., Schmidtke, Paul C., Pascarelle, Sebastian M., Griffiths, Richard E., Ratnatunga, Kavan U., ...
We present HST scale lengths and ground-based redshifts for 63 faint field galaxies down to 1 ≲ 21.5 mag from the Medium-Deep Survey. These have measured redshifts z ≲ 0.8 and half-light...
The morphology of faint galaxies in medium deep survey images using WFPC2 (1994)
Griffiths, Richard, Casertano, Stefano, Ratnatunga, Kavan U., Neuschaefer, Lyman W., Ellis, Richard S., Gilmore, Gerard F., ...
First results from HST Medium Deep Survey images taken with WFPC2 demonstrate that galaxy classifications can be reliably performed to magnitudes I814 less-than-or-similar-to 22.0 in the F815W band....
Windhorst, Rogier A., Schmidtke, Paul C., Pascarelle, Sebastian M., Gordon, J. M., Griffiths, Richard, Ratnatunga, Kavan U., ...
We present isophotal profiles of six faint field galaxies from some of the first deep images taken for the Hubble Space Telescope (HST) Medium Deep Survey (MDS). These have redshifts in the range...
Griffiths, Richard, Ratnatunga, Kavan U., Neuschaefer, Lyman W., Casertano, Stefano, Im, Myungshin, Wyckoff, Eric W., ...
We present results from the Medium Deep Survey (MDS), a Key Project using the Hubble Space Telescope. Wide Field Camera images of random fields have been taken in "parallel mode" with an effective...