Results for "Anton M. Koekemoer"

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The SEDs, Host Galaxies and Environments of Variability Selected AGN in GOODS-SJul 18 2012Jul 22 2012Variability selection has been proposed as a powerful tool for identifying both low-luminosity AGN and those with unusual SEDs. However, a systematic study of sources selected in such a way has been lacking. In this paper, we present the multi-wavelength ... More
On the Stellar Populations and Evolution of Star-Forming Galaxies at 6.3 < z < 8.6Dec 08 2009Jun 21 2010We study the physical characteristics of galaxies at 6.3 < z < 8.6, selected from deep near-infrared imaging with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope. Accounting for the photometric scatter using simulations, galaxies at ... More
Hubble Space Telescope Observations of the Associated Absorption Systems in Q0122+0338Oct 19 1999We have studied a spectrum of Q0122+0338 (z = 1.202) obtained by the FOS on board HST. We present the analysis of three associated absorption systems at z = 1.207, 1.199 and 1.166. The most complex of these at z = 1.207 shows strong absorption from the ... More
A Detection of Weak Lensing Magnification using Galaxy Sizes and MagnitudesNov 15 2011Nov 17 2011Weak lensing is commonly measured using shear through galaxy ellipticities, or using the effect of magnification bias on galaxy number densities. Here, we report on the first detection of weak lensing magnification with a new, independent technique using ... More
MC$^2$: Subaru and Hubble Space Telescope Weak-Lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9Oct 06 2017Nov 17 2017The second most significant detection of the Planck Sunyaev Zel'dovich survey, PLCK~G287.0+32.9 ($z=0.385$) boasts two similarly bright radio relics and a radio halo. One radio relic is located $\sim 400$ kpc northwest of the X-ray peak and the other ... More
Early-type galaxies in the PEARS survey: Probing the stellar populations at moderate redshiftAug 05 2009Aug 07 2009Using HST/ACS slitless grism spectra from the PEARS program, we study the stellar populations of morphologically selected early-type galaxies in the GOODS North and South fields. The sample - extracted from a visual classification of the (v2.0) HST/ACS ... More
3C236: Radio Source, Interrupted?Jan 24 2001We present new HST STIS/MAMA near-UV images and archival WFPC2 V and R band images which reveal the presence of four star forming regions in an arc along the edge of the dust lane in the giant (4 Mpc) radio galaxy 3C236. Two of the star forming regions ... More
The Lyman Continuum escape fraction of emission line-selected $z\sim2.5$ galaxies is less than 15%May 17 2017Recent work suggests that strong emission line, star-forming galaxies may be significant Lyman Continuum leakers. We combine archival HST broadband ultraviolet and optical imaging (F275W and F606W, respectively) with emission line catalogs derived from ... More
Weak Lensing Calibrated M-T Scaling Relation of Galaxy Groups in the COSMOS FieldSep 16 2013The scaling between X-ray observables and mass for galaxy clusters and groups is instrumental for cluster based cosmology and an important probe for the thermodynamics of the intracluster gas. We calibrate a scaling relation between the weak lensing mass ... More
Crowded Field Galaxy Photometry: Precision Colors in the CLASH ClustersSep 06 2017Nov 01 2017We present a new method for photometering objects in galaxy clusters. We introduce a mode-filtering technique for removing spatially variable backgrounds, improving both detection and photometric accuracy (roughly halving the scatter in the red sequence ... More
Secular evolution and a non-evolving black hole to galaxy mass ratio in the last 7 GyrSep 21 2011We present new constraints on the ratio of black hole (BH) mass to total galaxy stellar mass at 0.3<z<0.9 for a sample of 32 type-1 active galactic nuclei (AGNs) from the XMM-COSMOS survey covering the range M_BH/M_sun~10^(7.2--8.7). Virial M_BH estimates ... More
A Possible New Population of Sources with Extreme X-Ray / Optical RatiosJun 19 2003We describe a possible new class of X-ray sources that have robust detections in ultra-deep Chandra data, yet have no detections at all in our deep multi-band GOODS Hubble Space Telescope (HST) ACS images, which represent the highest quality optical imaging ... More
UVI colour gradients of 0.4<z<1.4 star-forming main sequence galaxies in CANDELS: dust extinction and star formation profilesMay 15 2017This paper uses radial colour profiles to infer the distributions of dust, gas and star formation in z=0.4-1.4 star-forming main sequence galaxies. We start with the standard UVJ-based method to estimate dust extinction and specific star formation rate ... More
MOIRCS Deep Survey. VI. Near-Infrared Spectroscopy of K-Selected Star-Forming Galaxies at z~2May 26 2010We present near-infrared (NIR) spectroscopy for 37 BzK-color-selected star-forming galaxies with MOIRCS on Subaru. The sample is drawn from the Ks-band selected catalog of the MOIRCS Deep Survey (MODS) in the GOODS-N region. About half of our samples ... More
Hubble Space Telescope Wide Field Camera 3 Observations of Escaping Lyman Continuum Radiation from Galaxies and Weak AGN at Redshifts $z$$\,\simeq\,$2.3-4.1Feb 04 2016Dec 21 2017We present observations of escaping Lyman Continuum (LyC) radiation from 34 massive star-forming galaxies and 12 weak AGN with reliably measured spectroscopic redshifts at $z$$\simeq$2.3-4.1. We analyzed Hubble Space Telescope Wide Field Camera 3 (WFC3) ... More
The Relationship between Galaxy and Dark Matter Halo Size from z~3 to the presentJan 12 2017May 12 2017We explore empirical constraints on the statistical relationship between the radial size of galaxies and the radius of their host dark matter halos from $z\sim 0.1$--3 using the GAMA and CANDELS surveys. We map dark matter halo mass to galaxy stellar ... More
Pathways to quiescence: SHARDS view on the Star Formation Histories of massive quiescent galaxies at 1.0 < z < 1.5Jul 28 2015Jan 21 2016We present Star Formation Histories (SFHs) for a sample of 104 massive (stellar mass M > 10$^{10}$ M$_{\odot}$) quiescent galaxies (MQGs) at $z$=1.0-1.5 from the analysis of spectro-photometric data from the SHARDS and HST/WFC3 G102 and G141 surveys of ... More
Morphologies and Spectral Energy Distributions of Extremely Red Galaxies in the GOODS-South FieldSep 05 2003Using U'- through Ks-band imaging data in the GOODS-South field, we construct a large, complete sample of 275 ``extremely red objects'' (EROs; K_s<22.0, R-K_s>3.35; AB), all with deep HST/ACS imaging in B_435, V_606, i_775, and z_850, and well-calibrated ... More
Unveiling the Phase Transition of the Universe During the Reionization Epoch with Lyman-alphaMar 11 2019The epoch of reionization (6 < z < 10) marks the period in our universe when the first large galaxies grew to fruition, and began to affect the universe around them. Massive stars, and potentially accreting supermassive black holes, filled the universe ... More
PdBI Cold Dust Imaging of Two Extremely Red H-[4.5]>4 Galaxies Discovered with SEDS and CANDELSMar 06 2014May 23 2014We report Plateau de Bure Interferometer (PdBI) 1.1 mm continuum imaging towards two extremely red H-[4.5]>4 (AB) galaxies at z>3, which we have previously discovered making use of Spitzer SEDS and Hubble Space Telescope CANDELS ultra-deep images of the ... More
Observational constraints on the merger history of galaxies since $z\approx6$: Probabilistic galaxy pair counts in the CANDELS fieldsMar 28 2019Galaxy mergers are expected to have a significant role in the mass assembly of galaxies in the early Universe, but there are very few observational constraints on the merger history of galaxies at $z>2$. We present the first study of galaxy major mergers ... More
Color and Stellar Population Gradients in Passively Evolving Galaxies at z~2 from HST/WFC3 Deep Imaging in the Hubble Ultra Deep FieldJan 04 2011May 05 2011We report the detection of color gradients in six massive (stellar mass > 10^{10} M_{sun}) and passively evolving (specific SFR < 10^{-11}/yr) galaxies at redshift 1.3<z<2.5 identified in the HUDF using HST ACS and WFC3/IR images. After matching different ... More
The FMOS-COSMOS survey of star-forming galaxies at $z\sim1.6$ VI: Redshift and emission-line catalog and basic properties of star-forming galaxiesDec 04 2018Dec 13 2018We present a new data release from the Fiber Multi-Object Spectrograph (FMOS)-COSMOS survey, which contains the measurements of spectroscopic redshift and flux of rest-frame optical emission lines (H$\alpha$, [NII], [SII], H$\beta$, [OIII]) for 1931 galaxies ... More
Measuring the Geometry of the Universe from Weak Gravitational Lensing behind Galaxy Groups in the HST COSMOS surveyNov 14 2011Gravitational lensing can provide pure geometric tests of the structure of space-time, for instance by determining empirically the angular diameter distance-redshift relation. This geometric test has been demonstrated several times using massive clusters ... More
Cross-correlation between X-ray and optical/near-infrared background intensity fluctuationsOct 06 2016Angular power spectra of optical and infrared background anisotropies at wavelengths between 0.5 to 5 $\mu$m are a useful probe of faint sources present during reionization, in addition to faint galaxies and diffuse signals at low redshift. The cross-correlation ... More
Hot-Dust-Poor Type 1 Active Galactic Nuclei in the COSMOS SurveySep 16 2010Nov 01 2010We report a sizable class of type 1 active galactic nuclei (AGNs) with unusually weak near-infrared (1-3{\mu}m) emission in the XMM-COSMOS type 1 AGN sample. The fraction of these "hot-dust-poor" AGNs increases with redshift from 6% at lowredshift (z ... More
The Hubble Ultra Deep FieldJul 27 2006This paper presents the Hubble Ultra Deep Field (HUDF), a one million second exposure of an 11 square minute-of-arc region in the southern sky with the Hubble Space Telescope. The exposure time was divided among four filters, F435W (B435), F606W (V606), ... More
Astro2020 Science White Paper: Assembly of the Most Massive Clusters at Cosmic NoonMar 12 2019Galaxy evolution is driven by many complex interrelated processes as galaxies accrete gas, form new stars, grow their stellar masses and central black holes, and subsequently quench. The processes that drive these transformations is poorly understood, ... More
Near-Infrared Imaging of a z=6.42 Quasar Host Galaxy With the Hubble Space Telescope Wide Field Camera 3Jul 13 2012Aug 09 2012We report on deep near-infrared F125W (J) and F160W (H) Hubble Space Telescope Wide Field Camera 3 images of the z=6.42 quasar J1148+5251 to attempt to detect rest-frame near-ultraviolet emission from the host galaxy. These observations included contemporaneous ... More
Breaking the Curve with CANDELS: A Bayesian Approach to Reveal the Non-Universality of the Dust-Attenuation Law at High RedshiftDec 16 2015May 25 2016Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant Universe. Here, we model the spectral energy distributions (SEDs) of galaxies at z = 1.5--3 ... More
Extended X-ray emission from non-thermal sources in the COSMOS field: A detailed study of a large radio galaxy at z=1.168Apr 11 2012X-ray selected galaxy group samples are usually generated by searching for extended X- ray sources that reflect the thermal radiation of the intragroup medium. On the other hand, large radio galaxies that regularly occupy galaxy groups also emit in the ... More
Quantifying the abundance of faint, low-redshift satellite galaxies in the COSMOS surveyMay 18 2018Faint dwarf satellite galaxies are important as tracers of small-scale structure, but remain poorly characterized outside the Local Group, due to the difficulty of identifying them consistently at larger distances. We review a recently proposed method ... More
On heat transfer in a thermally perturbed harmonic chainAug 06 2017Unsteady heat transfer in a harmonic chain is analyzed. Two types of thermal perturbations are considered: 1) initial instant temperature perturbation, 2) external heat supply. Closed equations describing the heat propagation are obtained and their analytical ... More
Pulse rate estimation using imaging photoplethysmography: generic framework and comparison of methods on a publicly available datasetOct 17 2017Objective: to establish an algorithmic framework and a benchmark dataset for comparing methods of pulse rate estimation using imaging photoplethysmography (iPPG). Approach: first we reveal essential steps of pulse rate estimation from facial video and ... More
Super-Teichmüller spaces and related structuresNov 25 2018This short note provides an overview of some theorems and conjectures obtained by the author and his collaborators. It is an extended abstract for the Oberwolfach workshop "New Trends in Teichm\"uller Theory and Mapping Class Groups", 2 September - 8 ... More
The Dust and Molecular Gas in the Brightest Cluster Galaxy in MACS 1931.8-2635May 03 2019We present new ALMA observations of the molecular gas and far-infrared continuum around the brightest cluster galaxy (BCG) in the cool-core cluster MACS 1931.8-2635. Our observations reveal $1.9 \pm 0.3 \times 10^{10}$ M$_{\odot}$ of molecular gas, on ... More
Dominant Nuclear Outflow Driving Mechanisms in Powerful Radio GalaxiesFeb 20 2007In order to identify the dominant nuclear outflow mechanisms in Active Galactic Nuclei, we have undertaken deep, high resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys (ACS) aboard ... More
A Very Large ($θ_{E}\gtrsim40$") Strong Gravitational Lens Selected with the Sunyaev-Zel'dovich Effect: PLCK G287.0+32.9 ($z$ = 0.38)Feb 16 2017May 03 2017Since galaxy clusters sit at the high-end of the mass function, the number of galaxy clusters both massive and concentrated enough to yield particularly large Einstein radii poses useful constraints on cosmological and structure formation models. To date, ... More
AGN and quasar science with aperture masking interferometry on the James Webb Space TelescopeJan 02 2014Mar 20 2014Due to feedback from accretion onto supermassive black holes (SMBHs), Active Galactic Nuclei (AGNs) are believed to play a key role in LambdaCDM cosmology and galaxy formation. However, AGNs' extreme luminosities and the small angular size of their accretion ... More
Superluminous supernovae at high redshiftFeb 08 2017Superluminous supernovae are beginning to be discovered at redshifts as early as the epoch of reionization. A number of candidate mechanisms is reviewed, together with the discovery programs.
The projected gravitational potential of the galaxy cluster MACS~J1206 derived from galaxy kinematicsJul 23 2015Sep 28 2015We reconstruct the radial profile of the projected gravitational potential of the galaxy cluster MACS-J1206 from 592 spectroscopic measurements of velocities of cluster members. For doing so, we use a method we have developed recently based on the Richardson-Lucy ... More
On the Transition of the Galaxy Quenching Mode at 0.5<z<1 in CANDELSMay 02 2018We investigate the galaxy quenching process at intermediate redshift using a sample of $\sim4400$ galaxies with $M_{\ast} > 10^{9}M_{\odot}$ between redshift 0.5 and 1.0 in all five CANDELS fields. We divide this sample, using the integrated specific ... More
Constraints on the Mass, Concentration, and Nonthermal Pressure Support of Six CLASH Clusters from a Joint Analysis of X-ray, SZ, and Lensing DataDec 16 2016We present a joint analysis of Chandra X-ray observations, Bolocam thermal Sunyaev-Zel'dovich (SZ) effect observations, Hubble Space Telescope (HST) strong lensing data, and HST and Subaru Suprime-Cam weak lensing data. The multiwavelength dataset is ... More
Bulge Growth and Quenching since z = 2.5 in CANDELS/3D-HSTFeb 04 2014Apr 17 2014Exploiting the deep high-resolution imaging of all 5 CANDELS fields, and accurate redshift information provided by 3D-HST, we investigate the relation between structure and stellar populations for a mass-selected sample of 6764 galaxies above 10^10 Msun, ... More
The Isophotal Structure of Star-forming Galaxies at $0.5< z <1.8$ in CANDELS: Implications for the Evolution of Galaxy StructureFeb 22 2018We have measured the radial profiles of isophotal ellipticity ($\varepsilon$) and disky/boxy parameter A$_4$ out to radii of about three times the semi-major axes for $\sim4,600$ star-forming galaxies (SFGs) at intermediate redshifts $0.5<z<1.8$ in the ... More
CANDELS Observations of the Environmental Dependence of the Color-Mass-Morphology Relation at z = 1.6May 03 2013We study the environmental dependence of color, stellar mass, and morphology by comparing galaxies in a forming cluster to those in the field at z = 1:6 with Hubble Space Telescope near-infrared imaging in the CANDELS/UDS field. We quantify the morphology ... More
The structural properties of classical bulges and discs from z~2Feb 11 2019Feb 13 2019We study the rest-frame optical mass-size relation of bulges and discs from z~2 to z~0 for a complete sample of massive galaxies in the CANDELS fields using 2 component S\'ersic models (Dimauro et a. 2018). Discs and star forming galaxies follow similar ... More
A catalog of polychromatic bulge-disk decompositions of ~ 17.600 galaxies in CANDELSMar 27 2018Mar 30 2018Understanding how bulges grow in galaxies is critical step towards unveiling the link between galaxy morphology and star-formation. To do so, it is necessary to decompose large sample of galaxies at different epochs into their main components (bulges ... More
CANDELS Sheds Light on the Environmental Quenching of Low-mass GalaxiesMay 04 2017May 16 2017We investigate the environmental quenching of galaxies, especially those with stellar masses (M*)$<10^{9.5} M_\odot$, beyond the local universe. Essentially all local low-mass quenched galaxies (QGs) are believed to live close to massive central galaxies, ... More
X-UDS: The Chandra Legacy Survey of the UKIDSS Ultra Deep Survey FieldSep 21 2018We present the X-UDS survey, a set of wide and deep Chandra observations of the Subaru-XMM Deep/UKIDSS Ultra Deep Survey (SXDS/UDS) field. The survey consists of 25 observations that cover a total area of 0.33 deg$^{2}$. The observations are combined ... More
CANDELS: The Contribution of the Observed Galaxy Population to Cosmic ReionizationJun 04 2012Jun 06 2012We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6<z<8. These galaxies were selected from new deep near-infrared HST imaging from the CANDELS, HUDF09 and ERS programs. In contrast to the majority ... More
On Star Formation Rates and Star Formation Histories of Galaxies out to z ~ 3Jun 27 2011We compare multi-wavelength SFR indicators out to z~3 in GOODS-South. Our analysis uniquely combines U-to-8um photometry from FIREWORKS, MIPS 24um and PACS 70, 100, and 160um photometry from the PEP survey, and Ha spectroscopy from the SINS survey. We ... More
Evidence for a correlation between the sizes of quiescent galaxies and local environment to z ~ 2Jul 11 2013Jul 15 2013We present evidence for a strong relationship between galaxy size and environment for the quiescent population in the redshift range 1 < z < 2. Environments were measured using projected galaxy overdensities on a scale of 400 kpc, as determined from ~ ... More
Lyman-alpha Forest Tomography from Background Galaxies: The First Megaparsec-Resolution Large-Scale Structure Map at z>2Sep 19 2014We present the first observations of foreground Lyman-$\alpha$ forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with $z\sim 2.3-2.8$ within a $5' \times 15'$ region of the COSMOS field. The transverse sightline ... More
Stellar Mass--Gas-phase Metallicity Relation at $0.5\leq z\leq0.7$: A Power Law with Increasing Scatter toward the Low-mass RegimeMar 15 2016Apr 14 2016We present the stellar mass ($M_{*}$)--gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts ($0.5\leq z\leq0.7$) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a ... More
Effect of local environment and stellar mass on galaxy quenching and morphology at $0.5<z<2.0$Jun 12 2017Sep 20 2017We study galactic star-formation activity as a function of environment and stellar mass over 0.5<z<2.0 using the FourStar Galaxy Evolution (ZFOURGE) survey. We estimate the galaxy environment using a Bayesian-motivated measure of the distance to the third ... More
The Bursty Star Formation Histories of Low-mass Galaxies at $0.4<z<1$ Revealed by Star Formation Rates Measured from H$β$ and FUVApr 18 2016Nov 16 2016We investigate the burstiness of star formation histories (SFHs) of galaxies at $0.4<z<1$ by using the ratio of star formation rates (SFRs) measured from H$\beta$ and FUV (1500 \AA) (H$\beta$--to--FUV ratio). Our sample contains 164 galaxies down to stellar ... More
The Nature of Optically Dull Active Galactic Nuclei in COSMOSOct 14 2009We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull AGNs in the COSMOS field. These objects exhibit the X-ray luminosity of an active galactic nucleus (AGN) but lack broad and narrow emission lines in their optical spectrum. ... More
Deep ATLAS radio observations of the CDFS-SWIRE fieldOct 18 2006We present the first results from the Australia Telescope Large Area Survey (ATLAS), which consist of deep radio observations of a 3.7 square degree field surrounding the Chandra Deep Field South, largely coincident with the infrared Spitzer Wide-Area ... More
The Herschel view of the dominant mode of galaxy growth from z=4 to the present daySep 18 2014Jan 07 2015We present an analysis of the deepest Herschel images in four major extragalactic fields GOODS-North, GOODS-South, UDS and COSMOS obtained within the GOODS-Herschel and CANDELS-Herschel key programs. The picture provided by 10497 individual far-infrared ... More
Deconstructing the Galaxy Stellar Mass Function with UKIDSS and CANDELS: the Impact of Colour, Structure and EnvironmentNov 12 2014We combine photometry from the UDS, and CANDELS UDS and CANDELS GOODS-S surveys to construct the galaxy stellar mass function probing both the low and high mass end accurately in the redshift range 0.3<z<3. The advantages of using a homogeneous concatenation ... More
Homotopy Algebras of Differential (Super)forms in Three and Four DimensionsFeb 12 2017We consider various $A_{\infty}$-algebras of differential (super)forms, which are related to gauge theories and demonstrate explicitly how certain reformulations of gauge theories lead to the transfer of the corresponding $A_{\infty}$-structures. In $N=2$ ... More
The bulk of the black hole growth since z~1 occurs in a secular universe: No major merger-AGN connectionSep 16 2010Nov 11 2010What is the relevance of major mergers and interactions as triggering mechanisms for active galactic nuclei (AGN) activity? To answer this longstanding question, we analyze 140 XMM-selected AGN host galaxies and a matched control sample of 1264 inactive ... More
The composite nature of Dust-Obscured Galaxies (DOGs) at z~2-3 in the COSMOS field: II. The AGN fractionApr 08 2019We present the X-ray properties of 108 Dust-Obscured Galaxies (DOGs; F$_{24 \mu m}$/F$_{R} >$ 1000) in the COSMOS field, all of which detected in at least three far-infrared bands with the Herschel Observatory. Out of the entire sample, 22 are individually ... More
Discovery of Massive, Mostly Star-formation Quenched Galaxies with Extremely Large Lyman-alpha Equivalent Widths at z ~ 3Jul 16 2015We report a discovery of 6 massive galaxies with both extremely large Lya equivalent width and evolved stellar population at z ~ 3. These MAssive Extremely STrong Lya emitting Objects (MAESTLOs) have been discovered in our large-volume systematic survey ... More
Inter-comparison of Radio-Loudness Criteria for Type 1 AGNs in the XMM-COSMOS SurveyAug 05 2014Limited studies have been performed on the radio-loud fraction in X-ray selected type 1 AGN samples. The consistency between various radio-loudness definitions also needs to be checked. We measure the radio-loudness of the 407 type 1 AGNs in the XMM-COSMOS ... More
Dynamics and Excitation of Radio Galaxy Emission-Line Regions - I. PKS 2356-61Nov 19 1997Results are presented from a programme of detailed longslit spectroscopic observations of the extended emission-line region (EELR) associated with the powerful radio galaxy PKS 2356-61. The observations have been used to construct spectroscopic datacubes, ... More
Redshifts of Emission Line Objects in the Hubble Ultra Deep FieldJan 30 2007We present redshifts for 115 emission line objects in the Hubble Ultra Deep Field (HUDF) identified through the GRism ACS Program for Extragalactic Science (GRAPES) project using the slitless grism spectroscopy mode of the ACS Camera on the Hubble Space ... More
Rest-frame UV--Optically Selected Galaxies at 2.3<z<3.5: Searching for Dusty Star-forming and Passively-Evolving GalaxiesOct 17 2011Apr 04 2012A new set of color selection criteria (VJL) analogous with the BzK method is designed to select both star-forming galaxies (SFGs) and passively-evolving galaxies (PEGs) at 2.3<z<3.5 by using rest-frame UV--optical (V-J vs. J-L) colors. The criteria are ... More
Discovery of a z = 7.452 High Equivalent Width Lyman-α Emitter from the Hubble Space Telescope Faint Infrared Grism SurveyDec 15 2017We present the results of an unbiased search for Ly{\alpha} emission from continuum-selected 6 < z < 8 galaxies. Our dataset consists of 160 orbits of G102 slitless grism spectroscopy obtained with the Hubble Space Telescope (HST) Wide Field Camera 3 ... More
Studying the Physical Properties of Tidal Features I. Extracting Morphological Substructure in CANDELS Observations and VELA SimulationsMar 26 2019The role of major mergers in galaxy evolution remains a key open question. Existing empirical merger identification methods use non-parametric and subjective visual classifications which can pose systematic challenges to constraining merger histories. ... More
A Type Ia Supernova at Redshift 1.55 in Hubble Space Telescope Infrared Observations from CANDELSJan 12 2012We report the discovery of a Type Ia supernova (SNIa) at redshift z=1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field, ... More
Galaxies in X-ray Groups I: Robust Membership Assignment and the Impact of Group Environments on QuenchingSep 27 2011Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend ... More
Evolution of the Sizes of Galaxies over 7<z<12 Revealed by the 2012 Hubble Ultra Deep Field CampaignDec 17 2012We analyze the redshift- and luminosity-dependent sizes of dropout galaxy candidates in the redshift range z~7-12 using deep images from the UDF12 campaign, data which offers two distinct advantages over that used in earlier work. Firstly, we utilize ... More
Spectral Energy Distributions of Type 1 AGN in XMM-COSMOS Survey II - Shape EvolutionOct 10 2012Nov 22 2013The mid-infrared to ultraviolet (0.1 -- 10 $\mu m$) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 AGN in the wide-field ``Cosmic Evolution Survey" (COSMOS) have been studied for signs of evolution. For a sub-sample ... More
X-ray spectral analyses of AGNs from the 7Ms Chandra Deep Field-South survey: the distribution, variability, and evolution of AGN's obscurationMar 02 2017Jun 09 2017We present a detailed spectral analysis of the brightest Active Galactic Nuclei (AGN) identified in the 7Ms Chandra Deep Field South (CDF-S) survey over a time span of 16 years. Using a model of an intrinsically absorbed power-law plus reflection, with ... More
The 2012 Hubble Ultra Deep Field (UDF12): Observational OverviewDec 06 2012We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128-orbit Cycle 19 \HST\ program aimed at extending previous WFC3/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, ... More
NICMOS StatusApr 19 2006We provide an overview of the most important calibration aspects of the NICMOS instrument on board of HST. We describe the performance of the instrument after the installation of the NICMOS Cooling System, and show that the behavior of the instrument ... More
Relations Between the Sizes of Galaxies and their Dark Matter Halos at Redshifts $0 < z < 3$Jan 15 2017Mar 22 2017We derive relations between the effective radii $R_{\rm{eff}}$ of galaxies and the virial radii $R_{200c}$ of their dark matter halos over the redshift range $0 < z < 3$. For galaxies, we use the measured sizes from deep images taken with \emph{Hubble ... More
Ultraviolet Luminosity Density of the Universe During the Epoch of ReionizationSep 09 2015The spatial fluctuations of the extragalactic background light trace the total emission from all stars and galaxies in the Universe. A multi-wavelength study can be used to measure the integrated emission from first galaxies during reionization when the ... More
Ultraviolet HST Snapshot Survey of 3CR Radio Source Counterparts at Low RedshiftDec 10 2001We present ultraviolet images of 27 3CR radio galaxies with redshifts z<0.1 that have been imaged with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). The observations employed the NUV-MAMA and broad-band filters ... More
Ultraviolet Morphologies and Star-Formation Rates of CLASH Brightest Cluster GalaxiesApr 02 2015Brightest cluster galaxies (BCGs) are usually quiescent, but many exhibit star formation. Here we exploit the opportunity provided by rest-frame UV imaging of galaxy clusters in the CLASH (Cluster Lensing and Supernovae with Hubble) Multi-Cycle Treasury ... More
The Nature of Massive Transition Galaxies in CANDELS, GAMA, and Cosmological SimulationsNov 11 2016Jul 14 2017We explore observational and theoretical constraints on how galaxies might transition between the "star-forming main sequence" (SFMS) and varying "degrees of quiescence" out to $z=3$. Our analysis is focused on galaxies with stellar mass $M_*>10^{10}M_{\odot}$, ... More
The Detection and Statistics of Giant Arcs Behind CLASH ClustersNov 12 2015We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated ... More
Smooth(er) Stellar Mass Maps in CANDELS: Constraints on the Longevity of Clumps in High-redshift Star-forming GalaxiesMar 12 2012May 10 2012We perform a detailed analysis of the resolved colors and stellar populations of a complete sample of 323 star-forming galaxies at 0.5 < z < 1.5, and 326 star-forming galaxies at 1.5 < z < 2.5 in the ERS and CANDELS-Deep region of GOODS-South. Galaxies ... More
Thermal equilibration in a one-dimensional harmonic crystal surrounded by a viscous environmentApr 26 2019May 04 2019The features for the unsteady process of thermal equilibration (the fast motions) in a one-dimensional harmonic crystal lying in a viscous environment (e.g., a gas) are under investigation. It is assumed that initially the displacements of all the particles ... More
Galaxy Structure and Mode of Star Formation in the SFR-Mass Plane from z ~ 2.5 to z ~ 0.1Jul 01 2011Oct 11 2011We analyze the dependence of galaxy structure (size and Sersic index) and mode of star formation (\Sigma_SFR and SFR_IR/SFR_UV) on the position of galaxies in the SFR versus Mass diagram. Our sample comprises roughly 640000 galaxies at z~0.1, 130000 galaxies ... More
CANDELS/GOODS-S, CDFS, ECDFS: Photometric Redshifts For Normal and for X-Ray-Detected GalaxiesSep 24 2014We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). The work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) ... More
No More Active Galactic Nuclei in Clumpy Disks Than in Smooth Galaxies at z~2 in CANDELS / 3D-HSTJul 28 2014We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3<z<2.4. We select galaxies undergoing gravitational ... More
UVUDF: Ultraviolet Through Near-infrared Catalog and Photometric Redshifts of Galaxies in the Hubble Ultra Deep FieldMay 05 2015We present photometry and derived redshifts from up to eleven bandpasses for 9927 galaxies in the Hubble Ultra Deep field (UDF), covering an observed wavelength range from the near-ultraviolet (NUV) to the near-infrared (NIR) with Hubble Space Telescope ... More
The distribution of satellites around massive galaxies at 1<z<3 in ZFOURGE/CANDELS: dependence on star formation activityJun 23 2014Jul 07 2014We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1<z<3 using imaging from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). ... More
Steady-state kinetic temperature distribution in a two-dimensional square harmonic scalar lattice lying in a viscous environment and subjected to a point heat sourceJan 07 2019Apr 26 2019We consider heat transfer in an infinite two-dimensional square harmonic scalar lattice lying in a viscous environment and subjected to a heat source. The basic equations for the particles of the lattice are stated in the form of a system of stochastic ... More
Fast and slow thermal processes in harmonic scalar latticesFeb 28 2017Nov 13 2017An approach for analytical description of thermal processes in harmonic lattices is presented. We cover longitudinal and transverse vibrations of chains and out-of-plane vibrations of two-dimensional lattices with interactions of an arbitrary number of ... More
A CANDELS WFC3 Grism Study of Emission-Line Galaxies at z~2: A Mix of Nuclear Activity and Low-Metallicity Star FormationAug 30 2011Feb 11 2012We present Hubble Space Telescope Wide Field Camera 3 slitless grism spectroscopy of 28 emission-line galaxies at z~2, in the GOODS-S region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). The high sensitivity of these ... More
A submillimetre galaxy at z=4.76 in the LABOCA survey of the Extended Chandra Deep Field SouthFeb 25 2009We report on the identification of the highest redshift submm-selected source currently known: LESSJ033229.4-275619. This source was detected in the Large Apex BOlometer CAmera (LABOCA) Extended Chandra Deep Field South (ECDFS) Submillimetre Survey (LESS), ... More
Quantum Group as Semi-infinite CohomologyDec 09 2008Apr 15 2010We obtain the quantum group $SL_q(2)$ as semi-infinite cohomology of the Virasoro algebra with values in a tensor product of two braided vertex operator algebras with complementary central charges $c+\bar{c}=26$. Each braided VOA is constructed from the ... More
On the completeness and Riesz basis property of root subspaces of boundary value problems for first order systems and applicationsJan 11 2014The paper is concerned with the completeness property of root functions of general boundary value problems for $n \times n$ first order systems of ordinary differential equations on a finite interval. In comparison with the recent paper [45] we substantially ... More
Prevalence of X-ray variability in the Chandra Deep Field SouthApr 21 2004We studied the X-ray variability of sources detected in the Chandra Deep Field South (Giacconi et al. 2002), nearly all of which are low to moderate z AGN (Tozzi et al. 2001). We find that 45% of the sources with >100 counts exhibit significant variability ... More
FIGS -- Faint Infrared Grism Survey: Description and Data ReductionJun 08 2017Jun 17 2017The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) ... More
A Two-Dimensional Spectroscopic Study of Emission Line Galaxies in the Faint Infrared Grism Survey (FIGS) I: Detection Method and CatalogJun 05 2018Nov 09 2018We present the results from the application of a two-dimensional emission line detection method, EMission-line two-Dimensional (EM2D), to the near-infrared G102 grism observations obtained with the Wide-Field Camera 3 (WFC3) as part of the Cycle 22 {\em ... More