Deep Spectroscopy of Ultra-Strong Emission Line Galaxies (2009)
Hu, Esther M., Cowie, Lennox L., Kakazu, Yuko, Barger, Amy J.
Ultra strong emission-line galaxies (USELs) with extremely high equivalent widths (EW(H beta) > 30A) can be used to pick out galaxies of extremely low metallicity in the z=0-1 redshift range. Large...
Abstract. Ly emission presents a means of identifying very high redshift galaxies, provided such objects can be reliably distinguished from foreground emission-line galaxies. Here we report on a...
Esther M. Hu, Richard G. Mcmahon
We present the results of ground-based and HST imaging studies targeted on z>4:5 quasar elds. High-redshift galaxies identi ed in deep narrow-band Ly images of the elds surrounding the quasars...
To appear in The Astronomical Journal (2008)
High-z Ly, Search Objects Near, Lennox L. Cowie, Esther M. Hu
We present deep narrow-band ( = 5390 A, =77A) and multi-color observations of the Hubble Deep Field and the Hawaii Deep Field SSA22 obtained with the LRIS instrument at the Keck II 10-m telescope. It...
Submitted to Nature 7/05/95; revised 8/31/95 (2007)
Lennox L. Cowie, Esther M. Hu, Antoinette Songaila, Spectroscopic Studies
The complex problem of when and how galaxies formed has not until recently been susceptible of direct attack. It has been known for some time that the excessive number of blue galaxies counted at...
Redshift Clustering In The Hubble Deep Field (2007)
Judith Cohen Lennox, Judith G. Cohen, Lennox L. Cowie, David W. Hogg, Antoinette Songaila, Roger Blandford, ...
We present initial results from a redshift survey carried out with the low-resolution imaging spectrograph on the 10 m W. M. Keck Telescope in the Hubble Deep Field. In the redshift distribution of...
Mapping the Youngest Galaxies to Redshift One (2007)
Kakazu, Yuko, Cowie, Lennox L., Hu, Esther M.
We describe results of a narrow band search for ultra-strong emission line galaxies (USELs) with EW(H beta) > 30 A. 542 candidate galaxies are found in a half square degree survey using two ~100...
The Stellar Population of Lyman-alpha Emitting Galaxies at z ~ 5.7 (2006)
Lai, Kamson, Huang, Jia-Sheng, Fazio, Giovanni, Cowie, Lennox L., Hu, Esther M., Kakazu, Yuko
We present a study of three Lyman-alpha emitting galaxies (LAEs), selected via a narrow-band survey in the GOODS northern field, and spectroscopically confirmed to have redshifts of z ~ 5.65. Using...
Spectroscopic Studies of z~5.7 and z~6.5 Galaxies: Implications for Reionization (2005)
Hu, Esther M., Cowie, Lennox L., Capak, Peter, Kakazu, Yuko
The recent development of large, complete samples which identify high-redshift galaxies at z~5.7 and z~6.5 from deep, wide-field surveys provides detailed information on the earliest galaxies, their...
The Team Keck Treasury Redshift Survey of the GOODS-North Field (2004)
Wirth, Gregory D., Willmer, Christopher N. A., Amico, Paola, Chaffee, Frederic H., Goodrich, Robert W., Kwok, Shui, ...
We report the results of an extensive imaging and spectroscopic survey in the GOODS-North field completed using DEIMOS on the Keck II telescope. Observations of 2018 targets in a magnitude-limited...
The Luminosity Function of Lyman Alpha Emitters at Redshift z~5.7 (2003)
Hu, Esther M., Cowie, Lennox L., Capak, Peter, McMahon, Richard G., Hayashino, Tomoki, Komiyama, Yutaka
We report results of a deep wide-field narrowband survey for redshift z~5.7 Ly alpha emitters carried out with SuprimeCam on Subaru 8.3-m telescope. Deep narrowband imaging of the SSA22 field through...
The Extended Emission-Line Region of 4C 37.43 (2002)
Stockton, Alan, MacKenty, John W., Hu, Esther M., Kim, Tae-Sun
We have explored the nature of the extended emission-line region around the z=0.37 quasar 4C 37.43, using extensive ground-based and HST imaging and spectroscopy. The velocity field of the ionized...
A Redshift z = 6.56 Galaxy Behind the Cluster Abell 370 (2002)
Hu, Esther M., Cowie, Lennox L., McMahon, Richard G., Capak, Peter, Iwamuro, Fumihide, Kneib, Jean-Paul, ...
We report the discovery of a redshift z=6.56 galaxy lying behind the cluster Abell 370. The object HCM 6A was found in a narrowband imaging survey using a 118 Angstrom bandpass filter centered at...
Galaxies at z>5: The View from Hawaii (1999)
Hu, Esther M., Cowie, Lennox L., McMahon, Richard G.
We review the properties of z>5 galaxies studied with HST and with the Keck telescopes, and discuss the detectability of Lyman alpha emission-line galaxies out to z~6.5 based on these data and...
Limits on the Gunn-Peterson Effect at z = 5 (1999)
Songaila, Antoinette, Hu, Esther M., Cowie, Lennox L., McMahon, Richard G.
We report new limits on the Gunn-Peterson effect at a redshift near 5 using spectroscopic observations of the z = 5 Sloan Digital Sky Survey quasar, J033829.31+002156.3, made with the LRIS and HIRES...
An Extremely Luminous Galaxy at z=5.74 (1999)
Hu, Esther M., McMahon, Richard G., Cowie, Lennox L.
We report the discovery of an extremely luminous galaxy lying at a redshift of z=5.74, SSA22-HCM1. The object was found in narrowband imaging of the SSA22 field using a 105 Angstrom bandpass filter...
The Density of Lyman-alpha Emitters at Very High Redshift (1998)
Hu, Esther M., Cowie, Lennox L., McMahon, Richard G.
We describe narrowband and spectroscopic searches for emission-line star forming galaxies in the redshift range 3 to 6 with the 10 m Keck II Telescope. These searches yield a substantial population...
Lyman alpha emission presents a means of identifying very high redshift galaxies, provided such objects can be reliably distinguished from foreground emission-line galaxies. Here we report on a...
Cowie, Lennox L., Hu, Esther M.
We present deep narrow-band (lambda = 5390 Angstroms, delta lambda = 77 Angstroms) and multi-color observations of the Hubble Deep Field and the Hawaii Deep Field SSA22 obtained with the LRIS...
Redshift Evolution of the Low-Column Density Lyman alpha Fores (1998)
Knowledge of the evolution of the low column density end of the Ly alpha forest (12.8 < log N_HI < 16.0 cm^-2) can provide substantial insight for models of structure formation and studies of the...
The Redshift Evolution of the Lyman Alpha Forest (1997)
Kim, Tae-Sun, Hu, Esther M., Cowie, Lennox L., Songaila, Antoinette
We have analyzed the properties of low column density Lyman alpha forest clouds (12.8 < log N_HI < 16.0) toward 5 QSOs at different redshifts, using high signal-to-noise data from the HIRES...
The Evolution of the Distribution of Star Formation Rates in Galaxies (1997)
Cowie, Lennox L., Hu, Esther M., Songaila, Antoinette, Egami, Eiichi
A large deep and nearly complete B
Hu, Esther M., McMahon, Richard G., Egami, Eiichi
We present the results of ground-based and HST imaging studies targeted on z>4.5 quasar fields. High-redshift galaxies identified in deep narrow-band Lyman alpha images of the fields surrounding the...
Redshift clustering in the Hubble Deep Field (1996)
Cohen, Judith G., Cowie, Lennox L., Hogg, David W., Songaila, Antoinette, Blandford, Roger, Hu, Esther M., ...
We present initial results from a redshift survey carried out with the Low Resolution Imaging Spectrograph on the 10~m W. M. Keck Telescope in the Hubble Deep Field. In the redshift distribution of...
Detection of Lyman-alpha Emitting Galaxies at Redshift z=4.55 (1996)
Hu, Esther M., McMahon, Richard G.
Studies of the formation and early history of galaxies have been hampered by the difficulties inherent in detecting faint galaxy populations at high redshift. As a consequence, observations at the...
Cowie, Lennox L., Songaila, Antoinette, Hu, Esther M., Cohen, J. G.
We present the results of spectroscopic studies with the LRIS spectrograph on Keck of two of the Hawaii deep survey fields. The 393 objects observed cover an area of 26.2 square arcmin and constitute...
REDSHIFT CLUSTERING IN THE HUBBLE DEEP FIELD 1 (1996)
Judith G. Cohen, Lennox L. Cowie, David W. Hogg, Roger Bl, Esther M. Hu, Patrick Shopbell
We present initial results from a redshift survey carried out with the Low Resolution Imaging Spectrograph on the 10 m W. M. Keck Telescope in the Hubble Deep Field. In the redshift distribution of...
Detection of a Lyman-alpha Emission-Line Companion to the z=4.69 QSO BR1202-0725 (1995)
Hu, Esther M., McMahon, Richard G., Egami, Eiichi
We report the detection of a nearby emission-line companion to the z=4.695 quasar BR1202-0725. Deep narrow-band exposures on this field from the UH 2.2 m show a Ly alpha flux of 1.5\times\ten{-16}...
Detection of Massive Forming Galaxies at Redshifts Greater than One (1995)
Cowie, Lennox L., Hu, Esther M., Songaila, Antoinette
The complex problem of when and how galaxies formed has not until recently been susceptible of direct attack. It has been known for some time that the excessive number of blue galaxies counted at...
Faintest Galaxy Morphologies from $HST$ WFPC2 Imaging of the Hawaii Survey Fields (1995)
Cowie, Lennox L., Hu, Esther M., Songaila, Antoinette
We present very deep $HST$ WFPC2 images in the F814W filter of two Hawaii Survey fields, SSA13 and SSA22. Using these data with previous ground-based imaging and spectroscopy, we compare the colors,...
The Distribution of Column Densities and b Values in the Lyman-Alpha Forest (1995)
Hu, Esther M., Kim, Tae-Sun, Cowie, Lennox L., Songaila, Antoinette, Rauch, Michael
We describe the properties of the Ly$\alpha$ forest in the column density range $\nhi \geq 2\times10^{12}$ cm$^{-2}$ based on 1056 lines in the wavelength range 4300--5100\AA measured in extremely...