Halo gas cross sections and covering fractions of MgII absorption selected galaxies (2008)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T.
We examine halo gas cross sections and covering fractions, fc, of intermediate-redshift Mg II absorption selected galaxies. We computed statistical absorber halo radii, Rx, using current values of...
Lawton, Brandon, Churchill, Christopher W., York, Brian A., Ellison, Sara L., Snow, Theodore P., Johnson, Rachel A., ...
We present equivalent width measurements and limits of six diffuse interstellar bands (DIBs) in seven damped Ly-alpha absorbers (DLAs) over the redshift range 0.091
Halo gas cross sections and covering fractions of Mg II absorption selected galaxies (2008)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T.
We examine halo gas cross sections and covering fractions, fc , of intermediate-redshift Mg II absorption selected galaxies. We computed statistical absorber halo radii, Rx, using current values of...
Halo gas cross sections and covering fractions of Mg II absorption selected galaxies (2008)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T.
We examine halo gas cross sections and covering fractions, fc , of intermediate-redshift Mg II absorption selected galaxies. We computed statistical absorber halo radii, Rx, using current values of...
A Correlation Between Galaxy Morphology and MgII Halo Absorption Strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
(Abridged) We compared the quantified morphological properties of 37 intermediate redshift MgII absorption selected galaxies to the properties of the absorbing halo gas, observed in the spectra of...
A correlation between galaxy morphology and Mg II halo absorption strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [ 0.03 angstrom
A correlation between galaxy morphology and Mg II halo absorption strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [ 0.03 angstrom
A correlation between galaxy morphology and Mg II halo absorption strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [ 0.03 angstrom
A correlation between galaxy morphology and Mg II halo absorption strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [ 0.03 angstrom
On the heterogeneity of metal-line and Lyα absorption in galaxy "halos" at z ∼ 0.7 (2007)
Churchill, Christopher W., Kacprzak, Glenn G., Evans, Jessica L.
Abstract not available.
A correlation between galaxy morphology and Mg II halo absorption strength (2007)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C., Murphy, Michael T., Evans, Jessica L.
We compared the quantified morphological properties of 37 intermediate redshift Mg II absorption selected galaxies to the properties of the absorbing halo gas [ 0.03 angstrom
On the heterogeneity of metal-line and Lyα absorption in galaxy "halos" at z ∼ 0.7 (2007)
Churchill, Christopher W., Kacprzak, Glenn G., Evans, Jessica L.
Abstract not available.
On the Heterogeneity of Metal-Line and Ly-Alpha Absorption in Galaxy "Halos" at z~0.7 (2006)
Churchill, Christopher W., Kacprzak, Glenn G., Steidel, Charles C., Evans, Jessica L.
We examine the properties of two galaxy "halos" at z ~ 0.7 in the TON 153 (z_em = 1.01) quasar field. The first absorber-galaxy pair (G1) is a z = 0.672, L_B = 4.3 L*_B, E/S0 galaxy probed at D = 58...
York, Brian A., Ellison, Sara L., Lawton, Brandon, Churchill, Christopher W., Snow, Theodore P., Johnson, Rachel A., ...
We report the first detection of the 5705 and 5780 A Diffuse Interstellar Bands (DIBs) in a moderate redshift Damped Lyman alpha (DLA) system. We measure a rest frame equivalent width of 63.2 +- 8.7...
First Detection of NaI D lines in High-Redshift Damped Lyman-alpha Systems (2006)
Kondo, Sohei, Kobayashi, Naoto, Minowa, Yosuke, Tsujimoto, Takuji, Churchill, Christopher W., Takato, Naruhisa, ...
A Near-infrared (1.18-1.35 micron) high-resolution spectrum of the gravitationally-lensed QSO APM 08279+5255 was obtained with the IRCS mounted on the Subaru Telescope using the AO system. We...
First detection of Na I D lines in high-redshift damped Lya Systems (2006)
Kondo, Sohei, Kobayashi, Naoto, Minowa, Yosuke, Tsujimoto, Takuji, Churchill, Christopher W., Takato, Naruhisa, ...
An NIR (1.18-1.35 mum) high-resolution spectrum of the gravitationally lensed QSO APM 08279+5255 was obtained with the Subaru Telescope IRCS using the AO system. We have detected strong Na I D...
Galaxy Morphology - Halo Gas Connections (2005)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C.
We studied a sample of 38 intermediate redshift MgII absorption-selected galaxies using (1) Keck/HIRES and VLT/UVES quasar spectra to measure the halo gas kinematics from MgII absorption profiles and...
A Search For Organic Molecules in Intermediate Redshift DLAs (2005)
Lawton, Brandon, York, Brian, Ellison, Sara L., Churchill, Christopher W., Johnson, Rachel A., Snow, Theodore P.
There has been a renewed interest in searching for diffuse interstellar bands (DIBs) due to their probable connection to organic molecules and, thus, their possible link to life in the Universe. Our...
MgII Absorption through Intermediate Redshift Galaxies (2005)
Churchill, Christopher W., Kacprzak, Glenn G., Steidel, Charles C.
The current status and remaining questions of MgII absorbers are reviewed with an eye toward new results incorporating high quality Hubble Space Telescope images of the absorbing galaxies. In the...
Models of five absorption-line systems along the line of sight toward PG 0117+213 (2005)
Masiero, Joseph R., Charlton, Jane C., Ding, Jie, Churchill, Christopher W., Kacprzak, Glenn G.
We present our investigation into the physical conditions of the gas in five intervening quasar absorption-line systems along the line of sight toward the quasar PG 0117+213, with redshifts of z =...
Galaxy morphology: halo gas connections (2005)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C.
We studied a sample of 38 intermediate redshift Mgii absorption-selected galaxies using (1) Keck/HIRES and VLT/UVES quasar spectra to measure the halo gas kinematics from Mgii absorption profiles and...
MgII absorption through intermediate redshift galaxies (2005)
Churchill, Christopher W., Kacprzak, Glenn G., Steidel, Charles C.
The current status and remaining questions of Mgii absorbers are reviewed with an eye toward new results incorporating high quality Hubble Space Telescope images of the absorbing galaxies. In the...
Galaxy morphology: halo gas connections (2005)
Kacprzak, Glenn G., Churchill, Christopher W., Steidel, Charles C.
We studied a sample of 38 intermediate redshift Mgii absorption-selected galaxies using (1) Keck/HIRES and VLT/UVES quasar spectra to measure the halo gas kinematics from Mgii absorption profiles and...
Models of five absorption-line systems along the line of sight toward PG 0117+213 (2005)
Masiero, Joseph R., Charlton, Jane C., Ding, Jie, Churchill, Christopher W., Kacprzak, Glenn G.
We present our investigation into the physical conditions of the gas in five intervening quasar absorption-line systems along the line of sight toward the quasar PG 0117+213, with redshifts of z =...
MgII absorption through intermediate redshift galaxies (2005)
Churchill, Christopher W., Kacprzak, Glenn G., Steidel, Charles C.
The current status and remaining questions of Mgii absorbers are reviewed with an eye toward new results incorporating high quality Hubble Space Telescope images of the absorbing galaxies. In the...
The Absorption Signature of Six MgII-Selected Systems Over 0.5 (2004)
Ding, Jie, Charlton, Jane C., Churchill, Christopher W.
We present the following results of photoionization modeling of six MgII-selected absorption systems, at redshift 0.5 < z 0.9, along lines of sight toward three quasars: PG 1241+176, PG 1248+401, and...
Zonak, Stephanie G., Charlton, Jane C., Ding, Jie, Churchill, Christopher W.
We analyze high resolution spectra of a multi--cloud weak [defined as W_r(MgII) < 0.3 A] absorbing system along the line of sight to PG 1634+706. This system gives rise to a partial Lyman limit break...
Mg II absorbing galaxies: morphologies and kinematics (2004)
Churchill, Christopher W., Steidel, Charles C., Kacprzak, Glenn G.
In this contribution, we review our current knowledge of the properties of galaxies, and their extended halos, selected by Mg II absorption in the spectra of background quasars. We then describe...
Mg II absorbing galaxies: morphologies and kinematics (2004)
Churchill, Christopher W., Steidel, Charles C., Kacprzak, Glenn G.
In this contribution, we review our current knowledge of the properties of galaxies, and their extended halos, selected by Mg II absorption in the spectra of background quasars. We then describe...
Phase Structure of Weak MgII Absorbers: Star Forming Pockets Outside of Galaxies (2001)
Charlton, Jane C., Churchill, Christopher W., Ding, Jie, Zonak, Stephanie, Bond, Nicholas, Rigby, Jane R.
A new and mysterious class of object has been revealed by the detection of numerous weak MgII doublets in quasar absorption line spectra. The properties of these objects will be reviewed. They are...
The Population of Weak MgII Absorbers. II The Properties of Single-Cloud Systems (2001)
Rigby, Jane R., Charlton, Jane C., Churchill, Christopher W.
We present an investigation of MgII absorbers characterized as single-cloud weak systems at z~1. We measured column densities and Doppler parameters for MgII and FeII in 15 systems found in...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Dzuba, V. A., Churchill, Christopher W., Prochaska, Jason X., ...
An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar (QSO) absorption-line spectra with...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Churchill, Christopher W., Prochaska, Jason X.
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we...
Further evidence for cosmological evolution of the fine structure constant (2001)
Webb, J. K., Murphy, M. T., Flambaum, Victor V., Dzuba, V. A., Barrow, John D., Churchill, Christopher W., ...
We describe the results of a search for time variability of the fine structure constant α using absorption systems in the spectra of distant quasars. Three large optical data sets and two 21 cm...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Dzuba, V. A., Churchill, Christopher W., Prochaska, Jason X., ...
An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar (QSO) absorption-line spectra with...
Murphy, M. T., Webb, J. K., Flambaum, Victor V., Churchill, Christopher W., Prochaska, Jason X.
Comparison of quasar (QSO) absorption spectra with laboratory spectra allows us to probe possible variations in the fundamental constants over cosmological time-scales. In a companion paper we...
Further evidence for cosmological evolution of the fine structure constant (2001)
Webb, J. K., Murphy, M. T., Flambaum, Victor V., Dzuba, V. A., Barrow, John D., Churchill, Christopher W., ...
We describe the results of a search for time variability of the fine structure constant α using absorption systems in the spectra of distant quasars. Three large optical data sets and two 21 cm...
H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6 (2000)
Bouche, Nicolas, Lowenthal, James D., Charlton, Jane C., Bershady, Matthew A., Churchill, Christopher W., Steidel, Charles C.
Despite previous intensive ground-based imaging and spectroscopic campaigns and wide-band HST imaging of the z=0.927 QSO 3C336 field, the galaxy that hosts the damped Ly-alpha system along this...
On the Origin of Intrinsic Narrow Absorption Lines in z (2000)
Ganguly, Rajib, Bond, Nicholas A., Charlton, Jane C., Eracleous, Michael, Brandt, W. N., Churchill, Christopher W.
We present a statistical analysis of the associated, high ionization narrow absorption line (NAL) systems in a sample of 59 QSOs defined from the HST QSO Absorption Line Key Project. We have compiled...
Churchill, Christopher W., Mellon, Richard R., Charlton, Jane C., Jannuzi, Buell T., Kirhakos, Sofia, Steidel, Charles C., ...
[Abridged] We examine a sample of 45 Mg II absorption-selected systems over the redshift range 0.4 to 1.4. Mg II and Fe II absorption profiles were observed at a resolution of ~6 km/s with...
Quasistellar Objects: Intervening Absorption Lines (2000)
Charlton, Jane C., Churchill, Christopher W.
We briefly review, at a level appropriate for graduate students and non-specialists, the field of quasar absorption lines (QALs). Emphasis is on the intervening absorbers. We present the anatomy of a...
Churchill, Christopher W., Mellon, Richard R., Charlton, Jane C., Jannuzi, Buell T., Kirhakos, Sofia, Steidel, Charles C., ...
We present extensive metal-line absorption properties for 45 absorption systems that were selected by their Mg II absorption at redshifts between 0.4 and 1.4. For each system the properties of...
QSO Absorption Line Constraints on Intragroup High-Velocity Clouds (2000)
Charlton, Jane C., Churchill, Christopher W., Rigby, Jane R.
We show that the number statistics of moderate redshift MgII and Lyman limit absorbers may rule out the hypothesis that high velocity clouds are infalling intragroup material.
An Unusual Mini-BAL Quasar at z=4.59 (1999)
Churchill, Christopher W., Schneider, Donald P., Schmidt, Maarten, Gunn, James E.
The z=4.591 quasar PC 1415+3408 exhibits very strong associated metal-line absorption from the N V (1238,1242), Si IV (1393,1402), and C IV (1548,1550) doublets spanning the velocity interval -1700 <...
Intrinsic Narrow Absorption Lines in HIRES/Keck Spectra of a Sample of Six Quasars (1999)
Ganguly, Rajib, Eracleous, Michael, Charlton, Jane C., Churchill, Christopher W.
In the course of a large intervening MgII survey of 25 quasars, the CIV emission lines of six (three radio-loud and three radio-quiet) were observed serendipitously. In four of these six quasars, we...
The Multiple Phases of Interstellar and Halo Gas in a Possible Group of Galaxies at z~1 (1998)
Churchill, Christopher W., Charlton, Jane C.
We used HIRES/Keck profiles (R=6 km/s) of MgII and FeII in combination with FOS/HST spectra (R=230 km/s) to place constraints on the physical conditions (metallicities, ionization conditions, and...
The Population of Weak Mg II Absorbers I. A Survey of 26 QSO HIRES/Keck Spectra (1998)
Churchill, Christopher W., Rigby, Jane R., Charlton, Jane C., Vogt, Steven S.
We present a search for "weak" MgII absorbers [those with W_r(2796) < 0.3 A in the HIRES/Keck spectra of 26 QSOs. We found 30, of which 23 are newly discovered. The spectra are 80% complete to...
A Search for Time Variation of the Fine Structure Constant (1998)
Webb, John K., Flambaum, Victor V., Churchill, Christopher W., Drinkwater, Michael J., Barrow, John D.
A method offering an order of magnitude sensitivity gain is described for using quasar spectra to investigate possible time or space variation in the fine structure constant, alpha. Applying the...
An Aluminum Enhanced Cloud in a CIV Absorber at z = 1.94 (1998)
Ganguly, Rajib, Churchill, Christopher W., Charlton, Jane C.
In the z=1.94 CIV absorption line system in the spectrum of quasar Q1222+228 (z_em=2.04), we find two clouds which have contrasting physical conditions, although they are only at a 17 km/s velocity...
Chromospheric Ca II H and K Emission Among Subdwarfs (1998)
Smith, Graeme H., Churchill, Christopher W.
Echelle spectra have been obtained of the Ca II H and K lines for a sample of metal-poor subdwarf stars as well as for a number of nearby Population I dwarfs selected from among those included in the...
Churchill, Christopher W., Brun, Vincent Le
We report the discovery of two iron-group enhanced high-metallicity Mg II absorbers in a search through 28 Lyman Alpha forest clouds along the PKS 0454+039 sight line. Based upon our survey and the...
The Kinematic Composition of MgII Absorbers (1997)
Charlton, Jane C., Churchill, Christopher W.
The study of galaxy evolution using quasar absorption lines requires an understanding of what components of galaxies and their surroundings are contributing to the absorption in various transitions....
Churchill, Christopher W., Charlton, Jane C.
Based upon QSO absorption line studies, galaxies at 0.3 < z < 1.0 are seen to have extended gaseous "halos". When the absorption lines are observed at high resolution, the velocity distribution of...
The Distribution of Gas In and Around Galaxies (1997)
Charlton, Jane C., Churchill, Christopher W.
A consensus is developing on the nature of various populations of absorbers at different redshift regimes and in particular on their relationships to galaxies at those epochs. As one example we...
Mg II Detection in the Lyman Alpha Forest: Metal Rich Cloud or LSB/Dwarf Galaxy? (1997)
Churchill, Christopher W., Brun, Vincent Le
We report the detection of Mg II absorption in two Lyman alpha forest clouds along the line of sight to PKS 0454+039. These clouds, at redshifts z=0.6248 and z=0.9315, respectively, also have strong...
Mg II Selected Absorbers: Ionization structures and a Survey of Weak Systems (1997)
First results from a study of high ionization absorption properties in roughly 30 Mg II absorption selected galaxies are presented. We have tested for correlations of Mg II, C IV, Si IV, N V, and O...
QSO Absorption Lines: The UV Rest-Frame from 0 < z < 4 (1997)
By charting the kinematic, chemical, and ionization conditions of galactic and intergalactic gas over the redshift range 0 - 4 with QSO absorption lines, the evolution of chemical abundances, the UV...
The low ionization gaseous content in intermediate redshift galaxies [microform] / (1997)
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On the Spatial and Kinematic Distributions of Mg II Absorbing Gas in =0.7 Galaxies (1996)
Churchill, Christopher W., Steidel, Charles C., Vogt, Steven S.
(Abridged) We present HIRES/Keck spectra having resolution 6 km/s of Mg II 2796 absorption profiles which arise in the gas associated with 15 identified galaxies over the redshift range 0.5 < z <...
MgII Absorbers: Disks, Halos, Satellites, and Pairs? (1996)
Charlton, Jane C., Churchill, Christopher W.
To understand which parts of galaxies give rise to the variety of observed MgII absorption profiles seen in QSO spectra, we have embarked upon a program to generate simulated absorption profiles as...
Establishing the Connections Between Galaxies and Mg II Absorbing Gas (1996)
HIRES/Keck spectra of Mg II (2796) absorption arising in the "halos" of 15 identified 0.4 < z < 0.9 galaxies are presented. Comparison of the galaxy and absorbing gas properties reveal that the...
QSO Absorption Line Systems as a Probe of Galaxies Like the Milky Way (1996)
Charlton, Jane C., Churchill, Christopher W.
Quasar absorption lines provide detailed information on the chemical, kinematic, and ionization conditions in galaxies and their environments, and provide a means for studying the evolution of these...
The Halo from the Outside In: QSO Absorption Lines (1996)
Churchill, Christopher W., Vogt, Steven S.
Studies of high resolution quasar absorption lines (QALs), arising from gas in local and z < 1.5 galaxies, provide direct probes of the kinematic, chemical, and ionization conditions and evolution of...
MgII Absorbers: Halos or Disks? (1996)
Charlton, Jane C., Churchill, Christopher W.
We challenge the conventional view that the majority of MgII/Lyman limit absorbers are extended halos of galaxies comprised of ``clouds'' with near-unity covering factor. The gaseous disks of spiral...
Probing Lyman-alpha Absorbers with Double Lines of Sight (1995)
Charlton, Jane C., Churchill, Christopher W., Linder, Suzanne M.
Study of Lyman-alpha absorption lines in the spectra of double line of sight (DLOS) quasars holds the promise of diagnosing the nature of the structures that give rise to Lyman-alpha absorption....