Ho, Luis C., Greene, Jenny E., Filippenko, Alexei V., Sargent, Wallace L. W.
We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published...
Ho, Luis C., Greene, Jenny E., Filippenko, Alexei V., Sargent, Wallace L. W.
We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published...
High-Redshift Metals. I. The Decline of C IV at z > 5.3 (2009)
Becker, George D., Rauch, Michael, Sargent, Wallace L. W.
We present the results from our search for C iv absorption systems at redshifts z = 5.3-6.0. We have observed four z ~ 6 QSOs with Keck/NIRSPEC in echelle mode. The data are the most sensitive yet...
High Redshift Metals I.: The Decline of C IV at z > 5.3 (2008)
Becker, George D., Rauch, Michael, Sargent, Wallace L. W.
We present the results from our search for C IV in the intergalactic medium at redshifts z=5.3-6.0. We have observed four z~6 QSOs with Keck/NIRSPEC in echelle mode. The data are the most sensitive...
Walsh, Jonelle L., Barth, Aaron J., Ho, Luis C., Filippenko, Alexei V., Rix, Hans-Walter, Shields, Joseph C., ...
We present Space Telescope Imaging Spectrograph observations of 14 nearby low-luminosity active galactic nuclei, including 13 LINERs and 1 Seyfert, taken at multiple parallel slit positions centered...
Walsh, Jonelle L., Barth, Aaron J., Ho, Luis C., Filippenko, Alexei V., Rix, Hans-Walter, Shields, Joseph C., ...
(Abridged) We present STIS observations of 14 nearby low-luminosity active galactic nuclei, including 13 LINERs and 1 Seyfert, taken at multiple parallel slit positions centered on the galaxy nuclei...
Viel, Matteo, Becker, George D., Bolton, James S., Haehnelt, Martin G., Rauch, Michael, Sargent, Wallace L. W.
Walsh, Jonelle L., Barth, Aaron J., Ho, Luis C., Filippenko, Alexei V., Rix, Hans-Walter, Shields, Joseph C., ...
We present Space Telescope Imaging Spectrograph observations of 14 nearby low-luminosity active galactic nuclei, including 13 LINERs and 1 Seyfert, taken at multiple parallel slit positions centered...
The Evolution of Optical Depth in the Lyα Forest: Evidence Against Reionization at z~6 (2007)
Becker, George D., Rauch, Michael, Sargent, Wallace L. W.
We examine the evolution of the IGM Lyα optical depth distribution using the transmitted flux probability distribution function (PDF) in a high-resolution sample of 55 QSOs spanning absorption...
Shields, Joseph C., Rix, Hans-Walter, Sarzi, Marc, Barth, Aaron J., Filippenko, Alexei V., Ho, Luis C., ...
We present results from a program of optical spectroscopy for 23 nearby galaxies with emission-line nuclei. This investigation takes advantage of the spatial resolution of the Hubble Space Telescope...
The Evolution of Optical Depth in the Ly-alpha Forest: Evidence Against Reionization at z~6 (2006)
Becker, George D., Rauch, Michael, Sargent, Wallace L. W.
We examine the evolution of the IGM Ly-alpha optical depth distribution using the transmitted flux probability distribution function (PDF) in a sample of 63 QSOs spanning absorption redshifts 1.7 < z...
Discovery of excess O I absorption towards the z = 6.42 QSO SDSS J1148+5251 (2005)
Becker, George D., Sargent, Wallace L. W., Rauch, Michael, Simcoe, Robert A.
We present a search for O I in the spectra of nine 4.9 < z_qso < 6.4 QSOs taken with Keck/HIRES. We detect six systems with N(O I) > 10^13.7 cm^{-2} in the redshift intervals where O I 1302 falls...
Expansion and Collapse in the Cosmic Web (2005)
Rauch, Michael, Becker, George D., Viel, Matteo, Sargent, Wallace L. W., Smette, Alain, Simcoe, Robert A., ...
We study the kinematics of the gaseous cosmic web at high redshift with Lyman alpha forest absorption in multiple QSO sightlines. Using a simple analytic model and a cosmological hydrodynamic...
Simcoe, Robert A., Sargent, Wallace L. W., Rauch, Michael, Becker, George D.
We present a study of galaxies and intergalactic gas toward the z=2.73 quasar HS1700+6416, to explore the effects of galaxy formation feedback on the IGM. Our observations and ionization simulations...
Lidz, Adam, Heitmann, Katrin, Hui, Lam, Habib, Salman, Rauch, Michael, Sargent, Wallace L. W.
The analysis of the Lyman-alpha forest of absorption lines in quasar spectra has emerged as a potentially powerful technique to constrain the linear matter power spectrum. In most previous work, the...
The stellar populations in the central parsecs of galactic bulges (2005)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., Ho, Luis C., Barth, Aaron J., Rudnick, Gregory, ...
The stellar populations in the central Parsecs of galactic bulges (2005)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., Ho, Luis C., Barth, Aaron J., Rudnick, Gregory, ...
We present Hubble Space Telescope blue spectra at intermediate spectral resolution for the nuclei of 23 nearby disk galaxies. These objects were selected to have nebular emission in their nuclei and...
Shields, Joseph C., Rix, Hans-Walter, Sarzi, Marc, Barth, Aaron J., Filippenko, Alexei V., Ho, Luis C., ...
We present results from a program of optical spectroscopy for 23 nearby galaxy emission-line nuclei. This investigation takes advantage of the spatial resolution of the Hubble Space Telescope to...
The Stellar Populations in the Central Parsecs of Galactic Bulges Central Stellar Populations (2004)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., Ho, Luis C., Barth, Aaron J., Rudnick, Gregory, ...
We present Hubble Space Telescope blue spectra at intermediate spectral resolution for the nuclei of 23 nearby disk galaxies. These objects were selected to have nebular emission in their nuclei, and...
Simcoe, Robert A., Sargent, Wallace L. W., Rauch, Michael
We present a direct measurement of the metallicity distribution function for the high redshift intergalactic medium. We determine the shape of this function using survival statistics, which account...
Metallicity of the intergalactic medium using pixel statistics: III. Silicon (2003)
Aguirre, Anthony, Schaye, Joop, Kim, Tae-Sun, Theuns, Tom, Rauch, Michael, Sargent, Wallace L. W.
(Modified) We study the abundance of silicon in the intergalactic medium by analyzing the statistics of SiIV, CIV, and HI pixel optical depths in a sample of 19 high-quality quasar absorption spectra...
Schaye, Joop, Aguirre, Anthony, Kim, Tae-Sun, Theuns, Tom, Rauch, Michael, Sargent, Wallace L. W.
(Modified) We measure the distribution of carbon in the intergalactic medium as a function of redshift z and overdensity delta. Using a hydrodynamical simulation to link the H I absorption to the...
SN 2002cx: The Most Peculiar Known Type Ia Supernova (2003)
Li, Weidong, Filippenko, Alexei V., Chornock, Ryan, Berger, Edo, Berlind, Perry, Calkins, Michael L., ...
We present photometric and spectroscopic observations of supernova (SN) 2002cx, which reveal it to be unique among all observed type Ia supernovae (SNe Ia). SN 2002cx exhibits a SN 1991T-like...
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
We use the database from Paper III to quantify the global and nuclear properties of emission-line nuclei in the Palomar spectroscopic survey of nearby galaxies. We show that the host galaxies of...
Simcoe, Robert A., Sargent, Wallace L. W., Rauch, Michael
We describe a survey for OVI absorption in the spectra of 5 high redshift quasars (2.2 < z < 2.8). We identify 12 cosmological systems, and 6 systems that are either ejected from the background QSO...
Limits on the Mass of the Central Black Hole in 16 Nearby Bulges (2002)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., McIntosh, Daniel H., Ho, Luis C., Rudnick, Gregory, ...
Measuring Black Hole Masses Using Ionized Gas Kinematics (2001)
Barth, Aaron J., Sarzi, Marc, Ho, Luis C., Rix, Hans-Walter, Shields, Joseph C., Filippenko, Alexei V., ...
We describe techniques for measuring the central masses of galaxies using emission-line kinematics observed with the Hubble Space Telescope. For accurate results, it is necessary to model various...
Limits on the Mass of the Central Black Hole in 16 Nearby Bulges (2001)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., McIntosh, Daniel H., Ho, Luis C., Rudnick, Greg, ...
We report upper limits on the masses of black holes that can be present in the centers of 16 nearby galaxy bulges. These limits for our statistically complete sample were derived from the modeling of...
Rauch, Michael, Sargent, Wallace L. W., Barlow, Thomas A., Carswell, Robert F.
Spectra from the Keck HIRES instrument of the Lyman alpha forests in the lines of sight to the A and C components of the gravitationally lensed QSO Q1422+231 were used to investigate the structure of...
Central Structural Parameters of Early-Type Galaxies as Viewed with HST/NICMOS (2001)
Ravindranath, Swara, Ho, Luis C., Peng, Chien Y., Filippenko, Alexei V., Sargent, Wallace L. W.
We present surface photometry for the central regions of a sample of 33 early-type (E, S0, and S0/a) galaxies observed at 1.6 microns (H band) using the Hubble Space Telescope (HST). We employ a new...
Small Scale Structure at High Redshift: II. Physical Properties of the CIV Absorbing Clouds (2001)
Rauch, Michael, Sargent, Wallace L. W., Barlow, Thomas A.
Keck HIRES spectra were obtained of the separate images of three gravitationally lensed QSOs (UM 673, Q1104-1804, and Q1422+2309). We studied the velocity and column density differences in CIV...
Detection of Nuclear X-ray Sources in Nearby Galaxies with Chandra (2001)
Ho, Luis C., Feigelson, Eric D., Townsley, Leisa K., Sambruna, Rita M., Garmire, Gordon P., Brandt, W. N., ...
We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using ACIS on board Chandra. The total sample consists of 41 low-luminosity AGNs, including Seyferts,...
Ravindranath, Swara, Ho, Luis C., Peng, Chien Y., Filippenko, Alexei V., Sargent, Wallace L. W.
We present preliminary results from surface photometry of a sample of early-type galaxies observed with NICMOS on board HST in the F160W (H-band) filter. Dust is found to occur mostly in galaxies...
Supermassive Black Holes from the SUNNS survey (2000)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., Rudnick, Greg, Ho, Luis C., McIntosh, Daniel H., ...
We report three new accurate mass measurements for the supermassive black holes hosted by the early-type disk galaxies NGC2787, NGC4459 and NGC4596. The targets were selected from a larger set of...
SuperMassive Black Holes in Bulges (2000)
Sarzi, Marc, Rix, Hans-Walter, Shields, Joseph C., Rudnick, Greg, Ho, Luis C., McIntosh, Daniel H., ...
We present spatially extended gas kinematics at parsec-scale resolution for the nuclear regions of four nearby disk galaxies, and model them as rotation of a gas disk in the joint potential of the...
The detection of oxygen in the low-density intergalactic medium (2000)
Schaye, Joop, Rauch, Michael, Sargent, Wallace L. W., Kim, Tae-Sun
The abundances of metals in the intergalactic medium (IGM) can be used to constrain the amount of star formation at high redshift and the spectral shape of the ionizing background radiation. For both...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue
The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of...
Double-Peaked Broad Emission Lines in NGC 4450 and Other LINERs (2000)
Ho, Luis C., Rudnick, Greg, Rix, Hans-Walter, Shields, Joseph C., McIntosh, Daniel H., Filippenko, Alexei V., ...
Spectra taken with HST reveal that NGC 4450 emits Balmer emission lines with displaced double peaks and extremely high-velocity wings. This characteristic line profile, previously seen in a few...
Evidence for a Black Hole and Accretion Disk in the LINER NGC 4203 (2000)
Shields, Joseph C., Rix, Hans-Walter, McIntosh, Daniel H., Ho, Luis C., Rudnick, Greg, Filippenko, Alexei V., ...
We present spectroscopic observations from the Hubble Space Telescope that reveal for the first time the presence of a broad pedestal of Balmer-line emission in the LINER galaxy NGC 4203. The...
Constraining reionization using the thermal history of the baryons (2000)
Schaye, Joop, Theuns, Tom, Rauch, Michael, Efstathiou, George, Sargent, Wallace L. W.
The thermal evolution of the intergalactic medium (IGM) depends on the reionization history of the universe. Numerical simulations indicate that the low density IGM, which is responsible for the low...
The thermal history of the intergalactic medium (1999)
Schaye, Joop, Theuns, Tom, Rauch, Michael, Efstathiou, George, Sargent, Wallace L. W.
At redshifts z >~ 2, most of the baryons reside in the smooth intergalactic medium which is responsible for the low column density Lyman-alpha forest. This photoheated gas follows a tight...
McDonald, Patrick, Miralda-Escude, Jordi, Rauch, Michael, Sargent, Wallace L. W., Barlow, Tom A., Cen, Renyue, ...
A sample of eight quasars observed at high resolution and signal-to-noise is used to determine the probability distribution function (PDF), the power spectrum, and the correlation function of the...
KECK HIRES Spectroscopy of APM 08279+5255 (1999)
Ellison, Sara L., Lewis, Geraint F., Pettini, Max, Sargent, Wallace L. W., Chaffee, Frederic H., Foltz, Craig B., ...
With an optical R-band magnitude of 15.2, the recently discovered z=3.911 BAL quasar APM 08279+5255 is an exceptionally bright high redshift source. Its brightness has allowed us to acquire a high...
Metal Abundances in the Lyman Alpha Forest (1999)
Ellison, Sara L., Lewis, Geraint F., Pettini, Max, Sargent, Wallace L. W., Chaffe, Frederic H., Irwin, Mike J.
We present high S/N echelle spectra of the recently discovered ultraluminous QSO APM 08279+5255 and use these data to re-examine the abundance of Carbon in Ly alpha forest clouds. In agreement with...
Glimpses of the Interstellar Medium at Redshift 3.5 (1998)
Rauch, Michael, Sargent, Wallace L. W., Barlow, Thomas A.
We have obtained high resolution (FWHM = 4.4 km/s) Keck spectra of images A and C of the gravitationally lensed QSO Q1422+231. The images are separated by 1.3" on the sky. In an absorption system at...
Boksenberg, Alec, Sargent, Wallace L. W., Rauch, Michael
An extremely careful separation of the weak metal-line systems relating to the Lyman forest absorbers into individual ``single-phase ionization'' components with accurate parameters has yielded a...
Ma, Chung-Pei, Small, Todd A., Sargent, Wallace L. W.
We present a summary report on a detailed study of the mass and dynamical state of the Corona Borealis supercluster using the largest redshift survey of this object to date. Extensive $N$-body...
Lopez, Sebastian, Reimers, Dieter, Rauch, Michael, Sargent, Wallace L. W., Smette, Alain
Using new HST/FOS, NTT/EMMI, and Keck/HIRES spectra of the gravitationally-lensed double QSO HE 1104-1805 AB (z=2.31, \theta=3.2), and assuming UV photoionization by a metagalactic radiation field,...
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A., Rauch, Michael
We investigate the metal contents of Lyman-alpha clouds at 2.2
Arav, Nahum, Barlow, Thomas A., Laor, Ari, Sargent, Wallace L. W., Blandford, Roger D.
We search for a direct signature of discrete ''clouds'' in the broad line region (BLR) of the Seyfert galaxy NGC 4151. For this purpose we apply cross correlation (CC) analysis to a high resolution...
Abundances of Heavy Elements and CO Molecules in High Redshift Damped Lyman-alpha Galaxies (1997)
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Damped Lyman-alpha systems seen in spectra of background quasars are generally thought to represent high redshift counterparts of present-day galaxies. We summarize observations of heavy element...
Abundances in Damped Lyman-alpha Systems and Chemical Evolution of High Redshift Galaxies (1997)
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Recent abundance measurements in damped Lyman-alpha galaxies, supplemented with unpublished Keck observations, are discussed. The metallicity distribution with cosmic time is examined for clues about...
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Galactic chemical evolution model calculations indicate that there should be considerable scatter in the observed N/O ratios at a fixed metallicity (O/H) for galaxies with very low metallicities due...
Lu, Limin, Savage, Blair D., Sembach, Kenneth R., Wakker, Bart P., Sargent, Wallace L. W., Oosterloo, Tom A.
We estimate the abundances of S and Fe in the high velocity cloud HVC 287.5+22.5+240, which has a velocity of +240 km/s with respect to the local standard of rest and is in the Galactic direction...
Small, Todd A., Sargent, Wallace L. W., Steidel, Charles C.
(abridged) Steidel & Sargent (1991a) found that the spectra of the components of the close quasar pairs Q1634+267A,B and Q2345+007A,B were in each case remarkably similar but that individual broad...
Small, Todd A., Ma, Chung-Pei, Sargent, Wallace L. W., Hamilton, Donald
(Abridged) We present a study of the structure and dynamics of the Corona Borealis Supercluster (z ~ 0.07) based on the redshifts for 528 galaxies in the supercluster. The galaxy distribution within...
Small, Todd A., Sargent, Wallace L. W., Hamilton, Donald
We measure the field galaxy luminosity function (LF) as a function of color and redshift from z = 0 to z = 0.5 using galaxies from the Norris Survey of the Corona Borealis Supercluster. We find that...
A Search for "Dwarf" Seyfert Nuclei. IV. Nuclei with Broad H-alpha Emission (1997)
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W., Peng, Chien Y.
We present the results of an optical spectroscopic survey designed to search for low-luminosity, "dwarf" Seyfert nuclei in a magnitude-limited sample of 486 bright, northern galaxies....
The Influence of Bars on Nuclear Activity (1997)
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
We test ideas on fueling of galactic nuclei by bar-driven inflow by comparing the detection rate and intensity of nuclear H II regions and AGNs among barred and unbarred galaxies in a sample of over...
Properties of H II Regions in the Centers of Nearby Galaxies (1997)
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
As part of an optical spectroscopic survey of nearby, bright galaxies, we have identified a sample of over 200 emission-line nuclei having optical spectra resembling those of giant extragalactic H II...
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
We have completed an optical spectroscopic survey of the nuclear regions (r < 200 pc) of a large sample of nearby galaxies. Although the main objectives of the survey are to search for low-luminosity...
A Search for "Dwarf" Seyfert Nuclei. V. Demographics of Nuclear Activity in Nearby Galaxies (1997)
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
We use the sample of emission-line nuclei derived from a recently completed optical spectroscopic survey of nearby galaxies to quantify the incidence of local (z = 0) nuclear activity. Consistent...
Initial Chemical Enrichment in Galaxies (1997)
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
We present evidence that damped Lyman-alpha galaxies detected in spectra of quasars may not have started forming stars until the redshift z~3. If damped Lyman-alpha absorbers are the progenitors of...
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Proof of the existence of a significant population of normal disk galaxies at redshift z>2 would have profound implications for theories of structure formation and evolution. We present evidence...
Low-Luminosity Seyfert Nuclei (1996)
Ho, Luis C., Filippenko, Alexei V., Sargent, Wallace L. W.
We describe a new sample of Seyfert nuclei discovered during the course of an optical spectroscopic survey of nearby galaxies. The majority of the objects, many recognized for the first time, have...
Abundances at High Redshifts: the Chemical Enrichment History of Damped Lyman-alpha Galaxies (1996)
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Damped Lyman-alpha absorption systems found in the spectra of high redshift quasars are believed to trace the interstellar gas in high redshift galaxies. In this paper, we study the elemental...
The Lyman-alpha Forest at z~4: Keck HIRES Observations of Q 0000-26 (1996)
Lu, Limin, Sargent, Wallace L. W., Womble, Donna S., Takada-Hidai, Masahide
This paper describes a study of the Lyman-alpha forest absorption clouds along the quasar sightline Q0000-26 (zem=4.1). The spectrum was obtained with the High Resolution Spectrometer on the 10m Keck...
The Chemical Enrichment History of Damped Lyman-alpha Galaxies (1996)
Lu, Limin, Sargent, Wallace L. W., Barlow, Thomas A.
Studies of damped Lyman-alpha absorption systems in quasar spectra are yielding very interesting results regarding the chemical evolution of these galaxies. We present some preliminary results from...