A5090712914- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Scientific Research and Discoveries
- Spectroscopy and Laser Applications
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Phase Equilibria and Thermodynamics
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- X-ray Spectroscopy and Fluorescence Analysis
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- CCD and CMOS Imaging Sensors
- Dark Matter and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Gas Dynamics and Kinetic Theory
- Calcium signaling and nucleotide metabolism
- Gaussian Processes and Bayesian Inference
- Impact of Light on Environment and Health
- Health Systems, Economic Evaluations, Quality of Life
- Aeolian processes and effects
University of California, Davis
2019-2025
University of Kentucky
2023-2025
University of Florida
2024
University of California, Los Angeles
2015-2023
University of Wisconsin–Madison
2014
Oral Roberts University
1977
In this paper we present the MOSFIRE Deep Evolution Field (MOSDEF) survey. The MOSDEF survey aims to obtain moderate-resolution (R=3000-3650) rest-frame optical spectra (~3700-7000 Angstrom) for ~1500 galaxies at 1.37<z<3.80 in three well-studied CANDELS fields: AEGIS, COSMOS, and GOODS-N. Targets are selected redshift intervals: 1.37<z<1.70, 2.09<z<2.61, 2.95<z<3.80, down fixed H_AB (F160W) magnitudes of 24.0, 24.5 25.0, respectively, using photometric spectroscopic catalogs from 3D-HST We...
We present results on the dust attenuation curve of z ∼ 2 galaxies using early observations from MOSFIRE Deep Evolution Field survey. Our sample consists 224 star-forming with zspec = 1.36–2.59 and high signal-to-noise ratio measurements Hα Hβ obtained Keck/MOSFIRE. construct composite spectral energy distributions (SEDs) in bins Balmer decrement to measure curve. find a that is similar SMC extinction at λ ≳ 2500 Å. At shorter wavelengths, shape identical Calzetti et al. relation, but lower...
Using observations from the MOSFIRE Deep Evolution Field (MOSDEF) survey, we investigate physical conditions of star-forming regions in $z\sim2.3$ galaxies, specifically electron density and ionization state. From measurements [O II]$\lambda\lambda$3726,3729 [S II]$\lambda\lambda$6716,6731 doublets, find a median $\sim250$ cm$^{-3}$ at $z\sim2.3$, an increase order magnitude compared to galaxies $z\sim0$. While are offset towards significantly higher O$_{32}$ values relative local fixed...
We present results on the excitation properties of z ∼ 2.3 galaxies using early observations from MOSFIRE Deep Evolution Field (MOSDEF) Survey. With its coverage full suite strong rest-frame optical emission lines, MOSDEF provides an unprecedented view spectra a representative sample distant star-forming galaxies. investigate locations in multiple emission-line diagnostic diagrams. These include [O iii]λ5007/Hβ vs. [N ii]/Hα and [S ii]λλ6717, 6731/Hα "BPT" diagrams, as well O32 R23 diagram....
We present detections of [OIII]$\lambda$4363 and direct-method metallicities for star-forming galaxies at $z=1.7-3.6$. combine new measurements from the MOSFIRE Deep Evolution Field (MOSDEF) survey with literature sources to construct a sample 18 $z>1$, spanning $7.5<1$2+log(O/H$)<8.2$ log(M$_*$/M$_{\odot})=7-10$. find that strong-line calibrations based on local analogs high-redshift reliably reproduce metallicity $z>1$ average. first mass-metallicity relation purely O/H, finding slope is...
Abstract The study of galaxy evolution hinges on our ability to interpret multiwavelength observations in terms their physical properties. To do this, we rely spectral energy distribution (SED) models, which allow us infer parameters from spectrophotometric data. In recent years, thanks wide and deep multiwave band surveys, the volume high-quality data have significantly increased. Alongside increased data, algorithms performing SED fitting improved, including better modeling prescriptions,...
Abstract We report detections of the [O iii ] λ 4364 auroral emission line for 16 galaxies at z = 2.1–8.7, measured from JWST/NIRSpec observations obtained as part Cosmic Evolution Early Release Science (CEERS) survey program. combine this CEERS sample with 9 objects literature 4−9 auroral-line and 21 1.4−3.7 ground-based spectroscopy. derive electron temperature ( T e ) direct-method oxygen abundances combined 46 star-forming 1.4−8.7. use these measurements to construct first high-redshift...
Abstract We utilize medium-resolution JWST/NIRSpec observations of 164 galaxies at z = 2.0–9.3 from the Cosmic Evolution Early Release Science (CEERS) survey to investigate evolution excitation and ionization properties high redshifts. Our results represent first statistical constraints on [O III ]/H β versus [N II α , [S I “BPT” diagrams > 2.7, analysis O 32 R 23 diagram 4 with a large sample. divide sample into five redshift bins containing 30–40 each. The subsamples ∼ 2.3, 3.3, 4.5 are...
Abstract We present results on the emission-line properties of z = 1.4–7.5 star-forming galaxies in Assembly Ultradeep Rest-optical Observations Revealing Astrophysics (AURORA) Cycle 1 JWST/NIRSpec program. Based its depth, continuous wavelength coverage from to 5 μ m, and medium spectral resolution ( R ∼ 1000), AURORA includes detections a large suite nebular emission lines spanning broad range rest-frame wavelength. investigate locations multiple different diagrams, including traditional...
Abstract The radial gradient of gas-phase metallicity is a powerful probe the chemical and structural evolution star-forming galaxies, closely tied to disk formation gas kinematics in early Universe. We present spatially resolved dynamical properties for sample 25 galaxies at 0.5 ≲ z 1.7 from MSA-3D survey. These innovative observations provide 3D spectroscopy spatial resolution approaching JWST’s diffraction limit high spectral R ≃ 2700. gradients measured our galaxy range −0.03 0.02 dex...
We present results on the z~2.3 mass-metallicity relation (MZR) using early observations from MOSFIRE Deep Evolution Field (MOSDEF) survey. use an initial sample of 87 star-forming galaxies with spectroscopic coverage H\beta, [OIII]\lambda 5007, H\alpha, and [NII]\lambda 6584 rest-frame optical emission lines, estimate gas-phase oxygen abundance based N2 O3N2 strong-line indicators. find a positive correlation between stellar mass metallicity among individual both also measure emission-line...
Abstract We investigate the nature of relation among stellar mass, star formation rate, and gas-phase metallicity (the <?CDATA ${M}_{* }$?> –SFR– Z relation) at high redshifts using a sample 260 star-forming galaxies z ∼ 2.3 from MOSDEF survey. present an analysis high-redshift based on several emission-line ratios for first time. show that clearly exists 2.3. The strength this is similar to predictions cosmological hydrodynamical simulations. By performing direct comparison stacks 0...
Abstract We derive a UV-optical stellar dust attenuation curve of galaxies at z = 1.4–2.6 as function gas-phase metallicity. use sample 218 star-forming galaxies, excluding those with very young or heavily obscured star formation, from the MOSFIRE Deep Evolution Field survey H α , β and [N ii ] λ 6585 spectroscopic measurements. constrain shape by comparing average flux densities sorted into bins obscuration using Balmer decrements, i.e., -to-H luminosities. The for high-metallicity (...
ABSTRACT We present results from the MOSFIRE Deep Evolution Field (MOSDEF) survey on identification, selection biases, and host galaxy properties of 55 X-ray, IR, optically selected active galactic nuclei (AGNs) at <?CDATA $1.4\lt z\lt 3.8$?> . obtain rest-frame optical spectra galaxies AGNs use BPT diagram to identify AGNs. examine uniqueness overlap identified different wavelengths. There is a strong bias against identifying any wavelength in low-mass galaxies, an additional IR most...
Far-ultraviolet (FUV; ~1200-2000 angstroms) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The launch JWST will soon usher in new era, pushing the UV spectroscopic frontier higher redshifts than ever before, however, its success hinges comprehensive star populations gas conditions that power observed spectral features. This requires level detail is only...
We present results from the NIRVANDELS survey investigating gas-phase metallicity ($\mathrm{Z}_{\mathrm{gas}}$, tracing O/H) and stellar ($Z_{\star}$, Fe/H) of 33 star-forming galaxies at redshifts $2.95 < z 3.80$. Based on a combined analysis deep optical near-IR spectra, rest-frame far ultraviolet respectively, we first simultaneous determination mass-metallicity relationships (MZRs) $z\simeq3.4$. In both cases, find that increases with increasing mass ($M_{\star}$), power-law slope...
We perform joint modeling of the composite rest-frame far-UV (FUV) and optical spectra redshift 1.85<z<3.49 star-forming galaxies to deduce key properties massive stars, ionized ISM, neutral with aim investigating principal factors affecting production escape Ly-alpha (Lya) photons. Our sample consists 136 deep Keck/LRIS MOSFIRE covering, respectively, Ly-beta through CIII] 1907, 1909; [OII], [NeIII], H-beta, [OIII], H-alpha, [NII], [SII]. Spectral photoionization indicate that are uniformly...
Abstract We present an analysis of the star formation rates (SFRs) and dust attenuation properties star-forming galaxies at 2.7 ≤ z < 6.5 drawn from Cosmic Evolution Early Release Science Survey. Our is based on JWST/NIRSpec Micro-Shutter Assembly R ∼ 1000 spectroscopic observations covering approximately 1–5 μ m. primary rest-frame optical measurements are H α /H β Balmer decrements, which we use as indicator nebular attenuation. In turn, decrements to obtain dust-corrected -based SFRs...
Abstract We present a joint analysis of the galaxy S04590 at z = 8.496 based on NIRSpec, NIRCam, and NIRISS observations obtained as part Early Release Observations program James Webb Space Telescope (JWST) far-infrared [C ii ] 158 μ m emission line detected by dedicated Atacama Large Millimeter/submillimeter Array (ALMA) observations. determine physical properties from modeling spectral energy distribution (SED) through redshifted optical nebular lines with JWST/NIRSpec. The best-fit SED...
Abstract The abundance of carbon relative to oxygen (C/O) is a promising probe star formation history in the early universe, as ratio changes with time due production these elements by different nucleosynthesis pathways. We present measurement <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi mathvariant="normal">C</mml:mi> <mml:mrow> stretchy="true">/</mml:mo> </mml:mrow>...
We use medium resolution JWST/NIRSpec observations from the Cosmic Evolution Early Release Science (CEERS) Survey to place first constraints on dust attenuation and star formation based Paschen lines for a sizable sample of 63 galaxies at redshifts z=1.0-3.1. Our analysis indicates strong correlations between Balmer decrement, Ha/Hb, line ratios that include (i.e., Paa/Hb, Pab/Hb, Paa/Pab), suggesting former is sensitive overall obscuration towards HII regions in high-redshift galaxies. The...
Abstract We examine the factors responsible for variation in ionization parameter ( U ) of high-redshift star-forming galaxies based on medium-resolution JWST/NIRSpec observations obtained by Cosmic Evolution Early Release Science survey. The sample consists 48 with redshifts z spec = 2.7−6.3, which are largely representative typical at these redshifts. [S ii ] λ 6718, 6733 doublet is used to estimate electron densities n e ), and dust-corrected H α luminosities compute ionizing photon rates...
We analyze the rest-optical emission-line ratios of star-forming galaxies at 2.7<=z<6.5 drawn from Cosmic Evolution Early Release Science (CEERS) Survey, and their relationships with stellar mass (M_*). Our analysis includes both line based on [NII]6583 feature -- [NII]6583/Ha, ([OIII]5007/Hb)/([NII]6583/Ha) (O3N2), [NII]6583/[OII]3727 those featuring alpha elements [OIII]5007/Hb, [OIII]5007/[OII]3727 (O_32), ([OIII]4959,5007+[OII]3727)/Hb (R_23), [NeIII]3869/[OII]3727. Given typical flux...
We present observations of CO(3-2) in 13 main-sequence $z=2.0-2.5$ star-forming galaxies at $\log(M_*/M_{\odot})=10.2-10.6$ that span a wide range metallicity (O/H) based on rest-optical spectroscopy. find CO(3-2)/SFR decreases with decreasing metallicity, implying the CO luminosity per unit gas mass is lower low-metallicity $z\sim2$. constrain CO-to-H$_2$ conversion factor ($\alpha_{\text{CO}}$) and $\alpha_{\text{CO}}$ inversely correlates derive molecular masses ($M_{\text{mol}}$)...
Galaxy metallicity scaling relations provide a powerful tool for understanding galaxy evolution, but obtaining unbiased global gas-phase oxygen abundances requires proper treatment of the various line-emitting sources within spectroscopic apertures. We present model framework that treats galaxies as ensembles HII and diffuse ionized gas (DIG) regions varying metallicities. These models are based upon empirical between line ratios electron temperature regions, DIG strong-line ratio from...