Jennifer M. Lotz
A5037646322- 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
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Advanced Vision and Imaging
- CCD and CMOS Imaging Sensors
- History and Developments in Astronomy
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Astrophysics and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Geophysics and Gravity Measurements
- Scientific Computing and Data Management
- Remote Sensing in Agriculture
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
- Astro and Planetary Science
- Cosmology and Gravitation Theories
- Optical Systems and Laser Technology
- Plant Water Relations and Carbon Dynamics
- Fluid Dynamics Simulations and Interactions
NSF’s NOIRLab
2022-2024
Space Telescope Science Institute
2012-2023
Community Science and Data Center
2022-2023
Gemini North Observatory
2020-2022
University of Copenhagen
2021
Johns Hopkins University
1998-2019
Capgemini (Netherlands)
2019
Gemini South Observatory
2019
NIU Observatory
2019
Bloomberg (United States)
1998-2018
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...
We analyze star formation (SF) as a function of stellar mass (M*) and redshift z in the All-Wavelength Extended Groth Strip International Survey. For 2905 field galaxies, complete to 1010(1010.8) M☉ at < 0.7(1), with Keck spectroscopic redshifts out = 1.1, we compile SF rates (SFRs) from emission lines, GALEX, Spitzer MIPS 24 μm photometry, optical-NIR M* measurements, HST morphologies. Galaxies reliable signs form distinct "main sequence" (MS), limited range SFRs given (1 σ ≲ ±0.3 dex),...
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,...
We present two new non-parametric methods for quantifying galaxy morphology: the relative distribution of pixel flux values (the Gini coefficient or G) and second-order moment brightest 20% galaxy's (M20). test robustness G M20 to decreasing signal-to-noise spatial resolution, find that both measures are reliable within 10% at average per greater than 3 resolutions better 1000 pc 500 pc, respectively. have measured M20, as well concentration (C), asymmetry (A), clumpiness (S) in rest-frame...
We describe the design and data sample from DEEP2 Galaxy Redshift Survey, densest largest precision-redshift survey of galaxies at z ~ 1 completed to date. The has conducted a comprehensive census massive galaxies, their properties, environments, large-scale structure down absolute magnitude M_B = -20 via ~90 nights observation on DEIMOS spectrograph Keck Observatory. covers an area 2.8 deg^2 divided into four separate fields, observed limiting apparent R_AB=24.1. Objects with < 0.7 are...
Galactic winds are a prime suspect for the metal enrichment of intergalactic medium and may have strong influence on chemical evolution galaxies nature QSO absorption line systems. We use sample 1406 galaxy spectra at z~1.4 from DEEP2 redshift survey to show that blueshifted Mg II 2796, 2803 A is ubiquitous in starforming this epoch. This first detection frequent outflowing galactic z~1. The presence depth independent AGN spectral signatures or morphology; major mergers not prerequisite...
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 present global structural parameter measurements of 109,533 unique, H_F160W-selected objects from the CANDELS multi-cycle treasury program. Sersic model fits for these are produced with GALFIT in all available near-infrared filters (H_F160W, J_F125W and, a subset, Y_F105W). The parameters best-fitting models (total magnitude, half-light radius, index, axis ratio, and position angle) made public, along newly constructed point spread functions each field filter. Random uncertainties...
We analyze star formation (SF) as a function of stellar mass (M_*) and redshift z in the All Wavelength Extended Groth Strip International Survey (AEGIS), for star-forming field galaxies with M_* >~ 10^10 M_sun out to z=1.1. The data indicate that high specific SF rates (SFR) many less massive do not represent late, irregular or recurrent, starbursts evolved galaxies. They rather seem reflect onset (initial burst) dominant episode galaxies, after which gradually declines on Gyr timescales...
Using HST/WFC3 imaging taken as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS), we examine role that major galaxy mergers play in triggering active galactic nuclei (AGN) activity at z~2. Our sample consists 72 moderate-luminosity (Lx ~ 1E42-1E44 erg/s) AGN 1.5<z<2.5 are selected using 4 Msec Chandra observations Field South, deepest X-ray to date. Employing visual classifications, have analyzed rest-frame optical morphologies host galaxies and compared...
We have generated synthetic images of ∼27 000 galaxies from the IllustrisTNG and original Illustris hydrodynamic cosmological simulations, designed to match Pan-STARRS observations log10(M*/M⊙) ≈ 9.8–11.3 at |$z$| 0.05. Most our were created with skirt radiative transfer code, including effects dust attenuation scattering, performing directly on Voronoi mesh used by simulations themselves. analysed both real newly developed statmorph which calculates non-parametric morphological diagnostics...
Abstract We present an investigation into the first 500 Myr of galaxy evolution from Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one 13 JWST ERS programs, targets formation z ∼ 0.5 to >10 using several imaging and spectroscopic modes. make use epoch CEERS NIRCam imaging, spanning 35.5 arcmin 2 , search for candidate galaxies at > 9. Following a detailed data reduction process implementing custom steps produce high-quality reduced images, we perform multiband...
We perform a detailed analysis of the resolved colors and stellar populations complete sample 323 star-forming galaxies at 0.5 < z 1.5, 326 1.5 2.5 in ERS CANDELS-Deep region GOODS-South. Galaxies were selected to be more massive than 10^10 Msun have specific star formation rates above 1/t_H. model 7-band optical ACS + near-IR WFC3 spectral energy distributions individual bins pixels, accounting simultaneously for galaxy-integrated photometric constraints available over longer wavelength...
We present the quantitative rest-frame B morphological evolution and galaxy merger fractions at 0.2 < z 1.2 as observed by All-wavelength Extended Groth Strip International Survey (AEGIS). use Gini coefficent M_20 to identify major mergers classify morphology for a volume-limited sample of 3009 galaxies brighter than 0.4 L_B^*, assuming pure luminosity 1.3 M_B per unit redshift. find that fraction remains roughly constant 10 +/- 2% 1.2. The E/S0/Sa increases from 21+/- 3% ~ 1.1 44 9% 0.3,...
We use HST/WFC3 imaging from the CANDELS Multicycle Treasury Survey, in conjunction with Sloan Digital Sky to explore evolution of galactic structure for galaxies stellar masses >3e10M_sun z=2.2 present epoch, a time span 10Gyr. relationship between rest-frame optical color, mass, star formation activity and galaxy structure. confirm dramatic increase day number density non-star-forming above 3e10M_sun reported by others. further find that vast majority these quiescent systems have...
Calculating the galaxy merger rate requires both a census of galaxies identified as candidates, and cosmologically-averaged `observability' timescale T_obs(z) for identifying mergers. While many have counted mergers using variety techniques, these techniques been poorly constrained. We address this problem by calibrating three estimators with suite hydrodynamic simulations formation models. estimate (1) close pairs range projected separations, (2) morphology indicator G-M20, (3) asymmetry A....
Abstract What are the faintest distant galaxies we can see with Hubble Space Telescope ( HST ) now, before launch of James Webb ? This is challenge taken up by Frontier Fields, a Director’s discretionary time campaign and Spitzer to deeper into universe than ever before. The Fields combines power natural gravitational telescopes massive high-magnification clusters produce deepest observations their lensed obtained. Six clusters—Abell 2744, MACSJ0416.1-2403, MACSJ0717.5+3745,...
We report the discovery of a candidate galaxy with photo-z z~12 in first epoch JWST Cosmic Evolution Early Release Science (CEERS) Survey. Following conservative selection criteria we identify source robust z_phot = 11.8^+0.3_-0.2 (1-sigma uncertainty) m_F200W=27.3, and >7-sigma detections five filters. The is not detected at lambda < 1.4um deep imaging from both HST JWST, has faint ~3-sigma F150W F160W, which signal Ly-alpha break near red edge filters, implying z~12. This object (Maisie's...
We report a new analysis of the Hubble Frontier Fields clusters Abell 2744 and MACS 0416 using wavelet decomposition to remove cluster light, enabling detection highly magnified (>50x) galaxies factor 10x fainter in luminosity than previous studies. find 167 at z > 6, with this sample we are able characterize UV function M_UV = -12.5 ~ -14 7 -15 8. steep faint-end slope (alpha consistent number faint needed reionize Universe under standard assumptions.
Abstract We present the data release and reduction process for Epoch 1 NIRCam observations Cosmic Evolution Early Release Science Survey (CEERS). These consist of imaging in six broadband filters (F115W, F150W, F200W, F277W, F356W F444W) one medium-band filter (F410M) over four pointings, obtained parallel with primary CEERS MIRI observations. reduced JWST Calibration Pipeline, custom modifications steps designed to address additional features challenges data. Here we provide a detailed...
Abstract We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of z ≃ 9 − 13 and M UV ∈ [ −21, −18] newly identified in NIRCam images the Cosmic Evolution Early Release Science Survey. confirm emission line 7 galaxies at = 7.762–8.998 using spectra ∼1–5 μ m either prism or its three medium-resolution ( R ∼ 1000) gratings. For candidates, we achieve a high confirmation rate ≃90%, which validates classical dropout selection from photometry. No robust lines...
Lyman Break Galaxy (LBG) candidates at z>10 are rapidly being identified in JWST/NIRCam observations. Due to the (redshifted) break produced by neutral hydrogen absorption of rest-frame UV photons, these sources expected drop out bluer filters while well detected redder filters. However, here we show that dust-enshrouded star-forming galaxies lower redshifts (z<7) may also mimic near-infrared (near-IR) colors LBGs, representing potential contaminants LBG candidate samples. First, analyze...
We present rest-frame optical emission-line flux ratio measurements for five $z>5$ galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in SMACS 0723 Early Release Observations. add several quality-control and post-processing steps to NIRSpec pipeline reduction products order ensure reliable relative calibration of emission lines that are closely separated wavelength, despite uncertain \textit{absolute} spectrophotometry current version reductions. Compared $z\sim3$ literature,...
The new capabilities that JWST offers in the near- and mid-infrared (IR) are used to investigate unprecedented detail nature of optical/near-IR faint, mid-IR bright sources, HST-dark galaxies among them. We gather data from CEERS survey EGS, jointly with HST data, analyze spatially resolved optical-to-mid-IR spectral energy distributions (SEDs) estimate both photometric redshifts 2 dimensions stellar populations properties a pixel-by-pixel basis. select 138 F150W-F356W>1.5 mag, F356W<27.5...
Abstract We present a comprehensive analysis of the evolution morphological and structural properties large sample galaxies at z = 3–9 using early James Webb Space Telescope (JWST) CEERS NIRCam observations. Our consists 850 > 3 detected in both Hubble (HST)/WFC3 JWST/NIRCam images, enabling comparison HST JWST morphologies. conduct set visual classifications, with each galaxy classified three times. also measure quantitative morphologies across all filters. find that have wide diversity...