Leonidas A. Moustakas
A5015312473- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Astrophysics and Star Formation Studies
- History and Developments in Astronomy
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Calibration and Measurement Techniques
- Pulsars and Gravitational Waves Research
- Geophysics and Gravity Measurements
- Spacecraft Design and Technology
- Computational Physics and Python Applications
- Astro and Planetary Science
- Relativity and Gravitational Theory
- Advanced Optical Sensing Technologies
- Photocathodes and Microchannel Plates
- Radioactive Decay and Measurement Techniques
Jet Propulsion Laboratory
2014-2024
California Institute of Technology
2009-2019
Carnegie Observatories
2015
European Southern Observatory
2012
Space Telescope Science Institute
2004-2007
University of Oxford
1997-2005
Michigan Science Center
2004
Science Oxford
2004
University of California, Berkeley
1993-2000
Berkeley College
1997
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over approximate redshift (z) range 8--1.5. It will image >250,000 distant galaxies using three separate cameras on Hubble Space Telescope, from mid-ultraviolet near-infrared, and find measure Type Ia supernovae at z>1.5 test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with...
This special issue of the Astrophysical Journal Letters is dedicated to presenting initial results from Great Observatories Origins Deep Survey (GOODS) that are primarily, but not exclusively, based on multiband imaging data obtained with Hubble Space Telescope and Advanced Camera for Surveys (ACS). The survey covers roughly 320 arcmin2 in ACS F435W, F606W, F814W, F850LP bands, divided into two well-studied fields. Existing deep observations Chandra X-Ray Observatory ground-based facilities...
This paper describes the Hubble Space Telescope imaging data products and reduction procedures for Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). survey is designed to document evolution of galaxies black holes at $z\sim1.5-8$, study Type Ia SNe beyond $z>1.5$. Five premier multi-wavelength sky regions are selected, each with extensive multiwavelength observations. The primary CANDELS consist obtained in Wide Field Camera 3 / infrared channel (WFC3/IR) UVIS channel,...
The Cluster Lensing And Supernova survey with Hubble (CLASH) is a 524-orbit multi-cycle treasury program to use the gravitational lensing properties of 25 galaxy clusters accurately constrain their mass distributions. survey, described in detail this paper, will definitively establish degree concentration dark matter cluster cores, key prediction CDM. CLASH sample larger and less biased than current samples space-based imaging studies similar depth, as we have minimized lensing-based...
We use cosmological simulations to study the effects of self-interacting dark matter (SIDM) on density profiles and substructure counts halos from scales spiral galaxies galaxy clusters, focusing explicitly models with cross sections over particle mass \sigma/m = 1 0.1 cm^2/g. Our rely a new SIDM N-body algorithm that is derived self-consistently Boltzmann equation reproduces analytic expectations in controlled numerical experiments. find well-resolved have constant-density cores,...
We report on a complete sample of seven luminous early-type galaxies in the Hubble Ultra Deep Field (UDF) with spectroscopic redshifts between 1.39 and 2.47, to KAB < 23. Using BzK selection criterion, we have preselected set objects over UDF, which fulfill photometric conditions for being passively evolving at z > 1.4. Low-resolution spectra these been extracted from Space Telescope (HST) ACS grism data taken UDF by Grism Program Extragalactic Science (GRAPES) project. Redshifts identified...
In this the first of a series Letters, we present panchromatic data set in Extended Groth Strip region sky. Our survey, All-Wavelength International Survey (AEGIS), aims to study physical properties and evolutionary processes galaxies at z ~ 1. It includes following deep, wide-field imaging sets: Chandra/ACIS X-ray, GALEX ultraviolet, CFHT/MegaCam Legacy optical, CFHT/CFH12K Hubble Space Telescope/ACS optical NICMOS near-infrared, Palomar/WIRC Spitzer/IRAC mid-infrared, Spitzer/MIPS...
We use stellar masses, surface photometry, strong-lensing and velocity dispersions (σe/2) to investigate empirical correlations for the definitive sample of 73 early-type galaxies (ETGs) that are strong gravitational lenses from SLACS survey. The traditional (fundamental plane (FP) its projections) consistent with those found non-lens galaxies, supporting thesis lens representative massive ETGs (dimensional mass Mdim = 1011–1012 M☉). addition high-precision estimates total allows us gain...
(Abridged) We present a joint gravitational lensing and stellar dynamical analysis of fifteen massive field early-type galaxies, selected from the Sloan Lens (SLACS) Survey. The following numerical results are found: (i) A joint-likelihood gives an average logarithmic density slope for total mass 2.01 (+0.02/-0.03) (68 perecnt C.L). inside Einstein radius. (ii) position-angle difference between light distribution is found to be 0+-3 degrees, setting upper limit <= 0.035 on external shear....
The Sloan Lens ACS (SLACS) Survey is an efficient Hubble Space Telescope Snapshot imaging survey for new galaxy-scale strong gravitational lenses. targeted lens candidates are selected spectroscopically from within the Digital Sky (SDSS) database of galaxy spectra having multiple nebular emission lines at a redshift significantly higher than that SDSS target galaxy. In this paper, we present catalog 19 newly discovered lenses, along with 9 other observed candidate systems either possible...
We present a weak gravitational lensing analysis of 22 early-type strong lens galaxies, based on deep HST images obtained as part the Sloan Lens ACS Survey. Using most advanced techniques to control systematic uncertainties related variable PSF and charge transfer efficiency ACS, we detect signal out 300 kpc/h. analyze blank fields from COSMOS survey in same manner, inferring that residual uncertainty tangential shear is <0.3%. A joint shows average total mass density profile consistent with...
We have measured the rest--frame lambda~1500 Ang comoving specific luminosity density of star--forming galaxies at redshift 3.5
We present the definitive data for full sample of 131 strong gravitational lens candidates observed with Advanced Camera Surveys (ACS) aboard Hubble Space Telescope by Sloan Lens ACS (SLACS) Survey. All targets were selected higher-redshift emission lines and lower-redshift continuum in a single Digital Sky Survey (SDSS) spectrum. The foreground galaxies are primarily early-type morphology, redshifts from approximately 0.05 to 0.5 velocity dispersions 160 km/s 400 km/s; faint background...
Based on 58 SLACS strong-lens early-type galaxies (ETGs) with direct total-mass and stellar-velocity dispersion measurements, we find that inside one effective radius massive elliptical Meff ≳ 3 × 1010 M☉ are well approximated by a power-law ellipsoid, an average logarithmic density slope of 〈γ'LD〉 ≡ −dlog(ρtot)/dlog(r) = 2.085+0.025−0.018 (random error mean) for isotropic orbits βr 0, ±0.1 (syst.) intrinsic scatter (all errors indicate the 68% CL). We no correlation γ'LD galaxy mass (Meff),...
We present a candidate for the most distant galaxy known to date with photometric redshift of z = 10.7+0.6−0.4 (95% confidence limits; < 9.5 galaxies types ruled out at 7.2σ). This J-dropout Lyman break galaxy, named MACS0647-JD, was discovered as part Cluster Lensing and Supernova survey Hubble (CLASH). observe three magnified images this due strong gravitational lensing by cluster MACSJ0647.7+7015 0.591. The are factors ∼80, 7, 2, brighter two observed ∼26th magnitude AB (∼0.15 μJy) in...
Aims. We present the full data set of spectroscopic campaign ESO/GOODS program in GOODS-South field, obtained with FORS2 spectrograph at ESO/VLT. Method. Objects were selected as candidates for VLT/FORS2 observations primarily based on expectation that detection and measurement their spectral features would benefit from high throughput resolution FORS2. The reliability redshift estimates is assessed using redshift-magnitude color-redshift diagrams, comparing results public data. Results....
Growing observational evidence now indicates that nebular line emission has a significant impact on the rest-frame optical fluxes of z~5-7 galaxies observed with Spitzer. This makes appear more massive, lower specific star formation rates. However, corrections for this have been very difficult to perform reliably due huge uncertainties overall strength such at z>~5.5. Here, we present most direct yet ubiquitous high-EW [OIII]+Hbeta in Lyman-break z~7, while also presenting strategy an...
We present a detailed strong-lensing, weak-lensing and X-ray analysis of Abell 2744 (z= 0.308), one the most actively merging galaxy clusters known. It appears to have unleashed 'dark', 'ghost', 'bullet' 'stripped' substructures, each ∼1014 M⊙. The phenomenology is complex will challenge for numerical simulations reproduce. With new, multiband Hubble Space Telescope (HST) imaging, we identify 34 strongly lensed images 11 galaxies around massive Southern 'core'. Combining this with data from...
We investigate the properties of massive galaxies at z=1-3.5 using HST observations, ground-based near-IR imaging, and Spitzer Space Telescope observations 3-24 micron. identify 153 distant red (DRGs) with J-K > 2.3 mag (Vega) in southern GOODS field. This sample is approximately complete stellar mass for passively evolving above 10^11 solar masses z < 3. The identified by this selection are roughly split between objects whose optical rest-frame light dominated evolved stars combined...
Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size axial ratio distribution as a function redshift at look-back times t > 8 Gyr. These parameters measured rest-frame UV wavelengths (1200 Å < λ 2000 Å) on with resolution less than 0.8 kpc. Galaxy radii found scale approximately parameter H-1(z). This is in accord theoretical expectation that typical sizes luminous parts should track expected evolution virial radius...
We present results from the Hubble Higher z Supernova Search, first space-based open field survey for supernovae (SNe). In cooperation with Great Observatories Origins Deep Survey, we have used Space Telescope Advanced Camera Surveys to cover ~300 arcmin2 in area of Chandra Field South and North on five separate search epochs (separated by ~45 day intervals) a limiting magnitude F850LP ≈ 26. These deep observations allowed us discover 42 SNe redshift range 0.2 < 1.6. As these data span large...
We conduct dissipationless N-body simulations to investigate the cumulative effect of substructure impacts onto thin disk galaxies in context ΛCDM paradigm. Our simulation campaign is based on a hybrid approach combining cosmological and controlled numerical experiments. Substructure properties are culled from galaxy-sized CDM halos. demonstrate that accretions massive subhalos central regions host halos, where galactic resides, since z ∼ 1 should be common occurrences. In contrast,...
We present the current photometric data set for Sloan Lens ACS (SLACS) Survey, including Hubble Space Telescope (HST) photometry from Advanced Camera Surveys, WFPC2, and NICMOS. These have enabled confirmation of an additional 15 grade "A" (certain) lens systems, bringing number SLACS lenses to 85; 13 "B" (likely) has identified nearly 100 candidates. Approximately 80% systems elliptical morphologies while ∼10% show spiral structure; remaining lenticular morphologies. Spectroscopic redshifts...
We have identified 335 galaxy cluster and group candidates, 106 of which are at z > 1, using a 4.5 um selected sample objects from 7.25 deg^2 region in the Spitzer Infrared Array Camera (IRAC) Shallow Survey. Clusters were as 3-dimensional overdensities wavelet algorithm, based on photometric redshift probability distributions derived IRAC NOAO Deep Wide-Field Survey data. estimate only ~10% detections spurious. To date 12 1 candidates been confirmed spectroscopically, redshifts 1.06 to...