Hsiao-wen Chen

On the Redshift Evolution of MgII Absorption Systems (2009)

Tinker, Jeremy L., Chen, Hsiao-Wen

We use a halo occupation approach to connect MgII absorbers to dark matter halos as a function of redshift. Using the model constructed in Tinker & Chen (2008), we parameterize the conditional...

Deep Keck u-band imaging of the Hubble Ultra Deep Field: A catalog of z~3 Lyman Break Galaxies (2009)

Rafelski, Marc, Wolfe, Arthur M., Cooke, Jeff, Chen, Hsiao-Wen, Armandroff, Taft E., Wirth, Gregory D.

We present a sample of 407 z~3 Lyman break galaxies (LBGs) to a limiting isophotal u-band magnitude of 27.6 mag in the Hubble Ultra Deep Field (UDF). The LBGs are selected using a combination of...

GRB 090426: The Environment of a Rest-Frame 0.35-second Gamma-Ray Burst at Redshift z=2.609 (2009)

Levesque, Emily M., Bloom, Joshua S., Butler, Nathaniel R., Perley, Daniel A., Cenko, S. Bradley, Prochaska, J. Xavier, ...

We present the discovery of an absorption-line redshift of z = 2.609 for GRB 090426, establishing the first firm lower limit to a redshift for a gamma-ray burst with an observed duration of 90%...

The Last Eight-Billion Years of Intergalactic CIV Evolution (2009)

Cooksey, Kathy L., Thom, Christopher, Prochaska, J. Xavier, Chen, Hsiao-Wen

We surveyed the HST UV spectra of 49 low-redshift quasars for z < 1 CIV candidates, relying solely on the characteristic wavelength separation of the doublet. After consideration of the defining...

Probing the IGM-Galaxy Connection at z < 0.5 I: A Galaxy Survey in QSO Fields and a Galaxy-Absorber Cross-Correlation Study (2009)

Chen, Hsiao-Wen, Mulchaey, John S.

(Abridged) We present an imaging and spectroscopic survey of galaxies in fields around QSOs HE0226-4110, PKS0405-123, and PG1216+069. The fields are selected to have ultraviolet echelle spectra...

Casting light on the 'anomalous' statistics of Mg II absorbers toward Gamma-Ray Burst afterglows: the incidence of weak systems (2009)

Tejos, Nicolas, Lopez, Sebastian, Prochaska, J. Xavier, Bloom, Joshua S., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, ...

We revisit echelle spectra (spectral resolution R ~ 40000) of 8 Gamma-Ray Burst afterglows to obtain the incidence (dN/dz) of weak intervening Mg II systems at a mean redshift of = 1.5. We show that...

The Galactic Environment of the NeVIII Absorber toward HE0226-4110 (2009)

Mulchaey, John S., Chen, Hsiao-Wen

We report the discovery of a small galaxy system in the vicinity of the NeVIII absorber at z=0.20701 toward HE0226-4110. The galaxy system consists of two 0.25 L* disk galaxies and a 0.05 L* galaxy...

Strong z~0.5 O VI Absorption Toward PKS 0405-123: Implications for Ionization and Metallicity of the Cosmic Web (2009)

Howk, J. Christopher, Ribaudo, Joseph S., Lehner, Nicolas, Prochaska, J. Xavier, Chen, Hsiao-Wen

We present observations of the O VI system at z_abs = 0.495096 toward PKS 0405-123 (z_em = 0.5726) obtained with FUSE and STIS. In addition to strong O VI, with log N(O VI) = 14.47+/-0.02, and...

The Clustering of MgII Absorption Systems at z=0.5 and Detection of Cold Gas in Massive Halos (2009)

Gauthier, Jean-Rene, Chen, Hsiao-Wen, Tinker, Jeremy L.

We measure the large-scale clustering of Mg II \lambda\lambda 2796,2803 absorbers with respect to a population of luminous red galaxies (LRGs) at z \sim 0.5. From the cross-correlation measurements...

Red nuggets at z simlar to 1.5: compact passive galaxies and the formation of the Kormendy relation (2009)

Damjanov, Ivana, McCarthy, Patrick J., Abraham, Roberto G., Glazebrook, Karl, Yan, Haojing, Mentuch, Erin, ...

We present the results of Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) imaging of a sample of 19 high-mass passively evolving galaxies with 1.2 < z < 2, taken primarily from the...

A near-infrared excess in the continuum of high-redshift galaxies: a tracer of star and planet formation? (2009)

Mentuch, Erin, Abraham, Roberto G., Glazebrook, Karl, McCarthy, Patrick J., Yan, Haojing, O'Donnell, Daniel V., ...

A broad continuum excess in the near-infrared, peaking in the rest frame at 2-5 micron, is detected in a spectroscopic sample of 88 galaxies at 0.5

Red nuggets at z similar to 1.5: compact passive galaxies and the formation of the Kormendy relation (2009)

Damjanov, Ivana, McCarthy, Patrick J., Abraham, Roberto G., Glazebrook, Karl, Yan, Haojing, Mentuch, Erin, ...

We present the results of Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) imaging of a sample of 19 high-mass passively evolving galaxies with 1.2 < z < 2, taken primarily from the Gemini...

A near-infrared excess in the continuum of high-redshift galaxies: a tracer of star and planet formation? (2009)

Mentuch, Erin, Abraham, Roberto G., Glazebrook, Karl, McCarthy, Patrick J., Yan, Haojing, O'Donnell, Daniel V., ...

A broad continuum excess in the near-infrared, peaking in the rest frame at 2-5 micron, is detected in a spectroscopic sample of 88 galaxies at 0.5

The A2A adenosine receptor rescues the urea cycle deficiency of Huntington's disease by enhancing the activity of the ubiquitin-proteasome system (2009)

Chiang, Ming-Chang, Chen, Hui-Mei, Lai, Hsing-Lin, Chen, Hsiao-Wen, Chou, Szu-Yi, Chen, Chiung-Mei, ...

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a CAG trinucleotide expansion in the Huntingtin (Htt) gene. The resultant mutant Htt protein (mHtt) forms...

High-Redshift Starbursting Dwarf Galaxies Revealed by GRB Afterglows (2008)

Chen, Hsiao-Wen, Perley, Daniel A., Pollack, Lindsey K., Prochaska, J. X., Bloom, J. S., Dessauges-Zavadsky, M., ...

We present a study of 15 long-duration gamma-ray burst (GRB) host galaxies at z>2. The GRBs are selected with available early-time afterglow spectra in order to compare interstellar medium (ISM)...

Red Nuggets at z~1.5: Compact passive galaxies and the formation of the Kormendy Relation (2008)

Damjanov, Ivana, McCarthy, Patrick J., Abraham, Roberto G., Glazebrook, Karl, Yan, Haojing, Mentuch, Erin, ...

We present the results of NICMOS imaging of a sample of 16 high mass passively evolving galaxies with 1.32, this is the first time such systems have been detected in a rest-frame optical survey at 1.3

A Survey for NV Absorption at z~z_GRB in GRB Afterglow Spectra: Clues to Gas Near the Progenitor Star (2008)

Prochaska, Jason X., Dessauges-Zavadsky, Miroslava, Ramirez-Ruiz, Enrico, Chen, Hsiao-Wen

We survey NV absorption in the afterglow spectra of long-duration gamma-ray bursts (GRBs) with the intent to study highly ionized gas in the galaxies hosting these events. We identify a high...

Resolving The ISM Surrounding GRBs with Afterglow Spectroscopy (2008)

Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.

We review current research related to spectroscopy of gamma-ray burst (GRB) afterglows with particular emphasis on the interstellar medium (ISM) of the galaxies hosting these high redshift events....

A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 I.: The Statistical Properties of Ionized Gas (2008)

Thom, Christopher, Chen, Hsiao-Wen

We have conducted a systematic survey for intervening OVI absorbers in available echelle spectra of 16 QSOs at z_QSO = 0.17-0.57. These spectra were obtained using HST/STIS with the E140M grating....

A STIS Survey for OVI Absorption Systems at 0.12 < z < 0.5 II.: Physical Conditions of the Ionised Gas (2008)

Thom, Christopher, Chen, Hsiao-Wen

We present a complete catalogue of 27 O VI absorbers at low redshift (0.12 < z < 0.5) from a blind survey of 16 QSO echelle spectra in the HST/STIS data archive. These absorbers are identified based...

The Baryon Content of Dark Matter Halos: Empirical Constraints from MgII Absorbers (2008)

Chen, Hsiao-Wen, Tinker, Jeremy L.

We have initiated a survey of MgII 2796, 2803 absorbers near known galaxies at projected distances rho

On the Halo Occupation of Dark Baryons (2007)

Tinker, Jeremy L., Chen, Hsiao-Wen

We introduce a new technique that adopts the halo occupation framework for understanding the origin of QSO absorption-line systems. Our initial study focuses specifically on MgII absorbers. We...

A compact cluster of massive red galaxies at a redshift of 1.5 (2007)

McCarthy, Patrick J., Yan, Haojing, Abraham, Roberto G., Mentuch, Erin, Glazebrook, Karl, Yan, Lin, ...

We describe a compact cluster or group of massive red galaxies at z = 1.5 discovered in one of the Gemini Deep Deep Survey (GDDS) fields. Deep H-band imaging from the Hubble Space Telescope (HST)...

A New Constraint on the Escape Fraction in Distant Galaxies Using Gamma-ray Burst Afterglow Spectroscopy (2007)

Chen, Hsiao-Wen, Prochaska, Jason X., Gnedin, Nickolay Y.

We describe a new method to measure the escape fraction fesc of ionizing radiation from distant star-forming galaxies using the afterglow spectra of long-duration gamma-ray bursts (GRBs). Optical...

Escape of Ionizing Radiation from High Redshift Galaxies (2007)

Gnedin, Nickolay Y., Kravtsov, Andrey V., Chen, Hsiao-Wen

We model the escape of ionizing radiation from high-redshift galaxies using high-resolution Adaptive Mesh Refinement N-body + hydrodynamics simulations. Our simulations include time-dependent and...

Super Star Cluster NGC1705-1: A Local Analogue to the Birthsite of Long-duration Gamma-ray Bursts (2007)

Chen, Hsiao-Wen, Prochaska, J. X., Bloom, Joshua S.

Recent observations suggest that global properties of the host galaxies for long-duration gamma-ray bursts (GRBs) are particularly well-suited for creating the massive star progenitors of these GRBs....

Characterizing the Low-Redshift Intergalactic Medium towards PKS1302-102 (2007)

Cooksey, Kathy L., Prochaska, Jason X., Chen, Hsiao-Wen, Mulchaey, John S., Weiner, Benjamin J.

We present a detailed analysis of the intergalactic metal-line absorption systems in the archival HST/STIS and FUSE ultraviolet spectra of the low-redshift quasar PKS1302-102 (z_QSO = 0.2784). We...

On the Incidence of C IV Absorbers Along the Sightlines to Gamma-Ray Bursts (2007)

Tejos, Nicolas, Lopez, Sebastian, Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava

We report on the statistics of strong (W_r > 0.15 A) C IV absorbers at z=1.5-3.5 toward high-redshift gamma-ray bursts (GRBs). In contrast with a recent survey for strong Mg II absorption systems at...

On the Nature of Velocity Fields in High z Galaxies (2007)

Prochaska, Jason X., Chen, Hsiao-Wen, Wolfe, Arthur M., Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.

We analyze the gas kinematics of damped Lya systems (DLAs) hosting high z gamma-ray bursts (GRBs) and those toward quasars (QSO-DLAs) focusing on threestatistics: (1) dv, the velocity interval...

Probing the ISM Near Star Forming Regions with GRB Afterglow Spectroscopy: Gas, Metals, and Dust (2007)

Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.

We study the chemical abundances of the interstellar medium surrounding high z gamma-ray bursts (GRBs) through analysis of the damped Lya systems (DLAs) identified in afterglow spectra. These...

Missing Molecular Hydrogen and the Physical Conditions of GRB Host Galaxies (2007)

Tumlinson, Jason, Prochaska, Jason X., Chen, Hsiao-Wen, Dessauges-Zavadsky, Miroslava, Bloom, Joshua S.

We examine the abundance of molecular hydrogen (H2) in the spectra of gamma ray burst afterglows (GRBs). In nearby galaxies H2 traces the cold neutral medium (CNM) and dense molecular star-forming...

The Gemini Deep Deep Survey: VIII. When Did Early-type Galaxies Form? (2007)

Abraham, Roberto G., Nair, Preethi, McCarthy, Patrick J., Glazebrook, Karl, Mentuch, Erin, Yan, Haojing, ...

We have used the Hubble Space Telescope's Advanced Camera for Surveys (Ford et al. 2003) to measure the cumulative mass density in morphologically-selected early-type galaxies over the redshift range...

When do early-type galaxies form? (2006)

Abraham, Roberto G., McCarthy, Patrick J., Mentuch, Erin, Glazebrook, Karl, Nair, Preethi, Gauthier, Jean-Rene, ...

We have used the Hubble Space Telescope's Advanced Camera for Surveys to measure the mass density function of morphologically selected early-type galaxies in the Gemini Deep Deep Survey fields, over...

On the absence of Wind Signatures in GRB Afterglow Spectra: Constraints on the Wolf-Rayet Winds of GRB Progenitors (2006)

Chen, Hsiao-Wen, Prochaska, Jason X., Ramirez-Ruiz, Enrico, Bloom, Joshua S., Dessauges-Zavadsky, Miroslava, Foley, Ryan J.

We investigate available constraints on the circumstellar medium (CSM) around long-duration gamma-ray burst (GRB) progenitors from afterglow spectra. We first establish a statistical sample of five...

On the incidence of strong MgII absorbers along gamma-ray burst sight lines (2006)

Prochter, Gabriel E., Prochaska, Jason X., Chen, Hsiao-Wen, Bloom, Joshua S., Dessauges-Zavadsky, Miroslava, Foley, Ryan J., ...

We report on a survey for strong ( rest equivalent width W-r >= 1 angstrom) intervening Mg II systems along the sight lines to long-duration gamma-ray bursts (GRBs). The GRB spectra that comprise the...

Searching for Low Surface-brightness Galaxies in the Hubble Ultra Deep Field: Implications for the Star Formation Efficiency in Neutral Gas at z ~ 3 (2006)

Wolfe, Arthur M., Chen, Hsiao-Wen

(Abridged) The Kennicutt--Schmidt law relates the face-on star formation rate (SFR) per unit area with the face-on gaseous column density in nearby galaxies. Applying this relation to damped Lya...

Temporal Variation in Excited Fe^+ Near a GRB Afterglow (2006)

Dessauges-Zavadsky, Miroslava, Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Joshua S., Barth, Aaron J.

Excited Si^+ and Fe^+ species are routinely observed in the host environment of gamma-ray burst (GRB) afterglows, but are not commonly seen in other extragalactic locations. Their presence signals...

A Shot in the Dark: A Technique for Locating the Stellar Counterparts of Damped Lyman Alpha Absorbers (2006)

O'Meara, John M., Chen, Hsiao-Wen, Kaplan, David L.

We present initial results from a Magellan telescope program to image galaxies that give rise to damped Lyman absorbers (DLAs) at 1.63 < z_DLA < 2.37. Our program differs from previous efforts in...

Probing the IGM/Galaxy Connection Toward PKS0405-123 III: The Galaxy Survey and Correlations with OVI Absorbers (2006)

Prochaska, Jason X., Weiner, Benjamin J., Chen, Hsiao-Wen, Mulchaey, John S.

We present a galaxy survey of the field surrounding PKS0405-123 performed with the WFCCD spectrometer at Las Campanas Observatory. The survey is comprised of two datasets: (1) a greater than 95%...

GRB Afterglows as a New Probe of the ISM and IGM at High Redshift (2006)

Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Josh S.

We summarize results from a study of the metallicity, relative abundances, gas density, and kinematics of dense media in the host environment of two Swift bursts, GRB050730 at z=3.968 and GRB051111...

Dissecting the Circumstellar Environment of Gamma-Ray Burst Progenitors (2006)

Prochaska, Jason X., Chen, Hsiao-Wen, Bloom, Joshua S.

We investigate properties of the interstellar medium (ISM) in galaxies hosting long-duration gamma-ray bursts (GRBs) from an analysis of atomic species (MgI, FeI) and excited fine-structure levels of...

High Metallicity, Photoionised Gas in Intergalactic Large-Scale Filaments (2005)

Aracil, Bastien, Tripp, Todd M., Bowen, David V., Proschaska, Jason X., Chen, Hsiao-Wen, Frye, Brenda L.

We present high-resolution UV spectra of absorption-line systems toward the low-z QSO HS0624+6907 (z=0.3700). Coupled with spectroscopic galaxy redshifts, we find that many of these absorbers are...

Echelle Spectroscopy of a GRB Afterglow at z=3.969: A New Probe of the Interstellar and Intergalactic Media in the Young Universe (2005)

Chen, Hsiao-Wen, Prochaska, Jason X., Bloom, Joshua S., Thompson, Ian B.

We present an echelle spectrum of the Swift GRB 050730, obtained four hours after the burst using the MIKE spectrograph on the Magellan Clay Telescope when the afterglow was at R=17.7. The spectrum...

Probing the IGM-Galaxy Connection Toward PKS0405-123 II : A Cross-Correlation Study of Lya Absorbers and Galaxies at z (2005)

Chen, Hsiao-Wen, Prochaska, Jason X., Weiner, Benjamin J., Mulchaey, John S., Williger, Gerard M.

We present a pilot study of the clustering properties of Lya absorbers with respect to known galaxies based on 112 Lya absorbers and 482 galaxies identified at z= 14 shows a comparable strength to...

The HST/ACS Grism Parallel Survey: II. First Results and a Catalog of Faint Emission-Line Galaxies at z < 1.6 (2005)

Drozdovsky, Igor, Yan, Lin, Chen, Hsiao-Wen, Stern, Daniel, Kennicutt Jr., Robert, Spinrad, Hyron, ...

We present the first results from the HST/ACS Grism Parallel Survey, a large program obtaining deep, slitless ACS grism spectroscopy of high-latitude HST parallel fields. We report on 11 high...

Gemini Deep Deep Survey VI: Massive Hdelta-strong galaxies at z=1 (2005)

Borgne, Damien Le, Abraham, Roberto, Daniel, Kathryne, McCarthy, Patrick, Glazebrook, Karl, Savaglio, Sandra, ...

We show that there has been a dramatic decline in the abundance of massive galaxies with strong Hdelta stellar absorption lines from z=1.2 to the present. These ``Hdelta-strong'', or HDS, galaxies...

Abundance Profiles and Kinematics of Damped Lyman-alpha Absorbing Galaxies at z < 0.65 (2004)

Chen, Hsiao-Wen, Kennicutt Jr, Robert C., Rauch, Michael

We present a spectroscopic study of six damped Lya absorption (DLA) systems at z 10^{11} h^{-1} M_sun appear to be common at intermediate redshifts. (3) Using an ensemble of six galaxy-DLA pairs, we...

Extended Neutral Gas Around z ~ 0.5 Galaxies: Properties of Damped Lya Absorbing Galaxies (2004)

Chen, Hsiao-Wen

I review current results from searching for galaxies giving rise to damped Lya absorbers (DLAs) at z

Probing the IGM/Galaxy Connection Toward PKS0405-123 I: UV Spectroscopy and Metal-Line Systems (2004)

Prochaska, Jason X., Chen, Hsiao-Wen, Howk, J. Christopher, Weiner, Benjamin J., Mulchaey, John

We present results from an analysis of FUSE and HST/STIS spectroscopy of the z_em=0.57 quasar PKS0405-123. We focus on the intervening metal-line systems identified along the sightline and...

Discovery of Massive Evolved Galaxies at z > 3 in the Hubble Ultra Deep Field (2004)

Chen, Hsiao-Wen, Marzke, Ron

We have identified six early-type galaxies at z>2.8 in the central 5.76 arcmin^2 Hubble Ultra Deep Field NICMOS region based on a pronounced broad-band discontinuity between the NICMOS F110W and...

HE 0047-1756: A new gravitationally lensed double QSO (2004)

Wisotzki, Lutz, Schechter, Paul L., Chen, Hsiao-Wen, Richstone, Douglas, Jahnke, Knud, Sanchez, Sebastian F., ...

The quasar HE 0047-1756, at z=1.67, is found to be split into two images 1.44" apart by an intervening galaxy acting as a gravitational lens. The flux ratio for the two components is roughly 3.5:1,...

The Host Galaxy of GRB 031203: Implications of its low metallicity, low redshift, and starburst nature (2004)

Prochaska, Jason X., Bloom, Joshua S., Chen, Hsiao-Wen, Hurley, Kevin C., Melbourne, Jason, Dressler, Alan, ...

We present Keck/NIRSPEC near-IR images and Magellan/IMACS optical spectroscopy of the host galaxy of GRB 031203. The host is an actively star-forming galaxy at z=0.1055 +/- 0.0001. This is the lowest...

The Gemini Deep Deep Survey: III. The abundance of massive galaxies 3-6 billion years after the Big Bang (2004)

Glazebrook, Karl, Abraham, Roberto, McCarthy, Patrick, Savaglio, Sandra, Chen, Hsiao-Wen, Crampton, David, ...

Hierarchical galaxy formation is the model whereby massive galaxies form from an assembly of smaller units. The most massive objects therefore form last. The model succeeds in describing the...

The Gemini Deep Deep Survey I: introduction to the survey, catalogs, and composite spectra (2004)

Abraham, Roberto G., Glazebrook, Karl, McCarthy, Patrick J., Crampton, David, Murowinski, Richard, Jorgensen, Inger, ...

The Gemini Deep Deep Survey (GDDS) is an ultradeep (K < 20.6 mag, I < 24.5 mag) redshift survey targeting galaxies in the "redshift desert" between z = 1 and z = 2. The primary goal of the...

The Gemini Deep Deep Survey II: metals in star-forming galaxies at redshift 1.3 less than z less than 2 (2004)

Savaglio, Sandra, Glazebrook, Karl, Abraham, Roberto G., Crampton, David, Chen, Hsiao-Wen, McCarthy, Patrick J., ...

The goal of the Gemini Deep Deep Survey (GDDS) is to study an unbiased sample of K < 20.6 galaxies in the redshift range 0.8 < z < 2.0. Here we determine the statistical properties of the...

Evolved galaxies at z greater than 1.5 from the Gemini Deep Deep survey: the formation epoch of massive stellar systems (2004)

McCarthy, Patrick J., Le Borgne, Damien, Crampton, David, Chen, Hsiao-Wen, Abraham, Roberto G., Glazebrook, Karl, ...

We present spectroscopic evidence from the Gemini Deep Deep Survey for a significant population of color-selected red galaxies at 1.3 < z, < 2.2 whose integrated light is dominated by evolved...

A high abundance of massive galaxies 3-6 billion years after the Big Bang (2004)

Glazebrook, Karl, Abraham, Roberto G., McCarthy, Patrick J., Savaglio, Sandra, Chen, Hsiao-Wen, Crampton, David, ...

Hierarchical galaxy formation is the model whereby massive galaxies form from an assembly of smaller units. The most massive objects therefore form last. The model succeeds in describing the...

The Gemini Deep Deep Survey I: introduction to the survey, catalogs, and composite spectra (2004)

Abraham, Roberto G., Glazebrook, Karl, McCarthy, Patrick J., Crampton, David, Murowinski, Richard, Jorgensen, Inger, ...

The Gemini Deep Deep Survey (GDDS) is an ultradeep (K < 20.6 mag, I < 24.5 mag) redshift survey targeting galaxies in the "redshift desert" between z = 1 and z = 2. The primary goal of the...

The Gemini Deep Deep Survey II: metals in star-forming galaxies at redshift 1.3 less than z less than 2 (2004)

Savaglio, Sandra, Glazebrook, Karl, Abraham, Roberto G., Crampton, David, Chen, Hsiao-Wen, McCarthy, Patrick J., ...

The goal of the Gemini Deep Deep Survey (GDDS) is to study an unbiased sample of K < 20.6 galaxies in the redshift range 0.8 < z < 2.0. Here we determine the statistical properties of the...

Evolved galaxies at z greater than 1.5 from the Gemini Deep Deep survey: the formation epoch of massive stellar systems (2004)

McCarthy, Patrick J., Le Borgne, Damien, Crampton, David, Chen, Hsiao-Wen, Abraham, Roberto G., Glazebrook, Karl, ...

We present spectroscopic evidence from the Gemini Deep Deep Survey for a significant population of color-selected red galaxies at 1.3 < z, < 2.2 whose integrated light is dominated by evolved...

A high abundance of massive galaxies 3-6 billion years after the Big Bang (2004)

Glazebrook, Karl, Abraham, Roberto G., McCarthy, Patrick J., Savaglio, Sandra, Chen, Hsiao-Wen, Crampton, David, ...

Hierarchical galaxy formation is the model whereby massive galaxies form from an assembly of smaller units. The most massive objects therefore form last. The model succeeds in describing the...

Rapid Growth of Massive Galaxies: A Paradox for Hierarchical Formation Models (2003)

Chen, Hsiao-Wen, Team, The LCIRS, Team, The GDDS

On behalf of the survey teams I summarize the designs and results of the Las Campanas Infrared Survey and Gemini Deep Deep Survey, both of which were initiated to understand the nature of red...

The Nature of Damped Ly-alpha Absorbing Galaxies at z (2003)

Chen, Hsiao-Wen, Lanzetta, Kenneth M.

We study the nature of damped Lya absorption (DLA) systems at z

Galaxies Associated with z~4 Damped Lya Systems: I. Imaging and Photometric Selection (2002)

Prochaska, Jason X., Gawiser, Eric, Wolfe, Arthur M., Quirrenbach, Andreas, Lanzetta, Kenneth M., Chen, Hsiao-Wen, ...

This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z~4 damped Lya systems. We present deep BRI images of three fields known to...

The Star Formation Rate Intensity Distribution Function--Implications for the Cosmic Star Formation Rate History of the Universe (2001)

Lanzetta, Kenneth M., Yahata, Noriaki, Pascarelle, Sebastian, Chen, Hsiao-Wen, Fernandez-Soto, Alberto

We address the effects of cosmological surface brightness dimming on observations of faint galaxies by examining the distribution of "unobscured" star formation rate intensities versus redshift. We...

The Las Campanas Infrared Survey. III. The H-band Imaging Survey and the Near-Infrared and Optical Photometric Catalogs (2001)

Chen, Hsiao-Wen, McCarthy, P. J., Marzke, R. O., Wilson, J., Carlberg, R. G., Firth, A. E., ...

(Abridged) The Las Campanas Infrared Survey, based on broad-band optical and near-infrared photometry, is designed to robustly identify a statistically significant and representative sample of...

Properties of a Chemically Enriched Lya Absorption System at z=0.167 and Implications for the Total Baryons in Extended Gaseous Envelopes Around Galaxies (2001)

Chen, Hsiao-Wen, Prochaska, Jason X., Lanzetta, Kenneth M.

We present a detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(HI) ~ 10^{16} cm^{-2}) at low redshift (z=0.167 towards PKS0405-1219). We...

PMN J0134-0931: A gravitationally lensed quasar with an unusual radio morphology (2001)

Winn, Joshua N., Lovell, James E. J., Chen, Hsiao-Wen, Fletcher, Andre B., Hewitt, Jacqueline N., Patnaik, Alok R., ...

The radio-loud quasar PMN J0134-0931 was discovered to have an unusual morphology during our search for gravitational lenses. In VLA and MERLIN images, there are 5 compact components with maximum...

Discovery of the Galaxy Proximity Effect and Implications for Measurements of the Ionizing Background Radiation at Low Redshifts (2001)

Pascarelle, Sebastian M., Lanzetta, Kenneth M., Chen, Hsiao-Wen, Webb, John K.

We present an analysis of galaxy and QSO absorption line pairs toward 24 QSOs at redshifts between z~0.2 and 1 in an effort to establish the relationship between galaxies and absorption lines in...

The Gaseous Extent of Galaxies and the Origin of Lya Absorption Systems. V. Optical and Near-Infrared Photometry of Lya-absorbing Galaxies at z < 1 (2001)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Webb, John K., Barcons, Xavier

(Abridged) We present results of a program to obtain and analyze HST WFPC2 images and ground-based images of galaxies identified in an imaging and spectroscopic survey of faint galaxies in fields of...

The Origin of C IV Absorption Systems at Redshifts z (2001)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Webb, John K.

(Abridged) We report the discovery of extended CIV gaseous envelopes around galaxies of a wide range of luminosity and morphological type. First, we show that CIV absorption systems are strongly...

The Unusual Spectral Energy Distribution of a Galaxy Previously Reported to be at Redshift 6.68 (2000)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Pascarelle, Sebastian, Yahata, Noriaki

Observations of distant galaxies are important both for understanding how galaxies form and for probing the physical conditions of the universe at the earliest epochs. It is, however, extremely...

Clustering of Very Red Galaxies in the Las Campanas IR Survey (2000)

McCarthy, Patrick, Carlberg, Ray, Marzke, Ron, Chen, Hsiao-Wen, Firth, Andrew, McMahon, Richard, ...

We report results from the first 1000 square arc-minutes of the Las Campanas IR survey. We have imaged 1 square degree of high latitude sky in six distinct fields to a 5-sigma H-band depth of 20.5...

The Origin of a Chemically Enriched lya Absorption System at z=0.167 (2000)

Chen, Hsiao-Wen, Prochaska, Jason X.

We present the first detailed analysis of the chemical abundances, ionization state, and origin of a partial Lyman limit system (N(\hI) ~ 10^{16} \cmjj) at low redshift (z=0.167 towards...

On the compared accuracy and reliability of spectroscopic and photometric redshift measurements (2000)

Fernandez-Soto, Alberto, Lanzetta, Kenneth M., Chen, Hsiao-Wen, Pascarelle, Sebastian M., Yahata, Noriaki

We present a comparison between the spectroscopic catalog of the HDF recently published by Cohen et al and the redshifts measured by our group for those objects using photometric techniques. We...

Photometry and Photometric Redshifts of Faint Galaxies in the Hubble Deep Field South NICMOS Field (2000)

Yahata, Noriaki, Lanzetta, Kenneth M., Chen, Hsiao-Wen, Fernandez-Soto, Alberto, Pascarelle, Sebastian M., Yahil, Amos, ...

We present a catalog of photometry and photometric redshifts of 335 faint objects in the HDF-S NICMOS field. The analysis is based on (1) infrared images obtained with the Hubble Space Telescope...

The Origin of \lya Absorption Systems at $z>1$---Implications from the Hubble Deep Field (1999)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Fernández-Soto, Alberto

The Hubble Deep Field images have provided us with a unique chance to relate statistical properties of high-redshift galaxies to statistical properties of \lya absorption systems. Combining an {\em...

Galaxies of Redshift z > 5: The View from Stony Brook (1999)

Lanzetta, Kenneth M., Chen, Hsiao-Wen, Fernandez-Soto, Alberto, Pascarelle, Sebastian, Yahata, Noriaki, Yahil, Amos

We report on some aspects of our efforts to establish properties of the extremely faint galaxy population by applying our photometric redshift technique to the HDF and HDF-S WFPC2 and NICMOS fields....

The Stony Brook Photometric Redshifts of Faint Galaxies in the Hubble Deep Fields (1999)

Lanzetta, Kenneth M., Chen, Hsiao-Wen, Fernandez-Soto, Alberto, Pascarelle, Sebastian, Puetter, Rick, Yahata, Noriaki, ...

We report on some aspects of the current status of our efforts to establish properties of faint galaxies by applying our photometric redshift technique to faint galaxies in the HDF and HDF-S WFPC2...

Photometric/Spectroscopic Redshift Identification of Faint Galaxies in STIS Slitless Spectroscopy Observations (1999)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Pascarelle, Sebastian

We present a new spectrum extraction technique which employs optimal weights for the spectral extraction, deblends the overlapping spectra, determines the precise sky background, and takes into...

A Spectroscopically Identified Galaxy of Probable Redshift z = 6.68 (1999)

Chen, Hsiao-Wen, Lanzetta, Kenneth M., Pascarelle, Sebastian

The detection and identification of distant galaxies is a prominent goal of observational cosmology because distant galaxies are seen as they were in the distant past and hence probe early galaxy...

Photometry and photometric redshifts of faint . . . (1999)

Noriaki Yahata, Kenneth M. Lanzetta, Hsiao-Wen Chen, Alberto Fernandez-Soto, Sebastian M. Pascarelle, Amos Yahil, ...

We present a catalog of photometry and photometric redshifts of 335 faint objects in the Hubble Deep Field South near-infrared camera and multiobject spectrograph (NICMOS) Ðeld. The analysis is...

Photometry and Photometric Redshifts of Galaxies in the Hubble Deep Field South Nicmos Field (1998)

Chen, Hsiao-Wen, Fernandez-Soto, Alberto, Lanzetta, Kenneth M., Pascarelle, Sebastian M., Puetter, Richard C., Yahata, Noriaki, ...

We present an electronic catalog of infrared and optical photometry and photometric redshifts of 323 galaxies in the Hubble Deep Field South NICMOS field at...

Constraints on the Unseen Galaxy Population from the Lyman-alpha Forest (1998)

Lanzetta, Kenneth M., Chen, Hsiao-Wen, Webb, John K., Barcons, Xavier

Here we describe results of our attempt to determine what types of galaxies are responsible for the Lyman-alpha forest absorption systems, based on our ongoing imaging and spectroscopic survey of...

Galaxies at Redshifts z > 5 (1998)

Lanzetta, Kenneth M., Chen, Hsiao-Wen, Pascarelle, Sebastian, Yahata, Noriaki

Here we describe our attempts to establish statistically complete samples of very high redshift galaxies by obtaining photometric redshifts of galaxies in Medium Deep Survey (MDS) fields and...

Damped Lyman-alpha Absorption Associated with an Early-Type Galaxy at Redshift z = 0.16377 (1997)

Lanzetta, Kenneth M., Wolfe, Arthur M., Altan, Hakan, Barcons, Xavier, Chen, Hsiao-Wen, Fernandez-Soto, Alberto, ...

We report new HST and ground-based observations of a damped Lyman-alpha absorption system toward the QSO 0850+4400. The redshift of the absorption system is z = 0.163770 and the neutral hydrogen...

Fluxes of organic pollutants from the sediments of Boston Harbor / (1993)

Chen, Hsiao-Wen.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1993.

Mammalian Polynucleotide Phosphorylase Is an Intermembrane Space RNase That Maintains Mitochondrial Homeostasis▿

Chen, Hsiao-Wen, Rainey, Robert N., Balatoni, Cynthia E., Dawson, David W., Troke, Joshua J., Wasiak, Sylwia, ...

We recently identified polynucleotide phosphorylase (PNPase) as a potential binding partner for the TCL1 oncoprotein. Mammalian PNPase exhibits exoribonuclease and poly(A) polymerase activities, and...

A New Function in Translocation for the Mitochondrial i-AAA Protease Yme1: Import of Polynucleotide Phosphorylase into the Intermembrane Space▿ †

Rainey, Robert N., Glavin, Jenny D., Chen, Hsiao-Wen, French, Samuel W., Teitell, Michael A., Koehler, Carla M.

Polynucleotide phosphorylase (PNPase) is an exoribonuclease and poly(A) polymerase postulated to function in the cytosol and mitochondrial matrix. Prior overexpression studies resulted in PNPase...