525 citations · 2.9k across the 29 of their papers we have counts for
29 papers
Spatially-Resolved Temperature and Density Structures of Nearby HII regions
Yifei Jin, Ralph Sutherland, Lisa Kewley +1
Photoionization models frequently assume constant temperature or density within HII regions. We investigate this assumption by measuring the detailed temperature and density struct…
CEERS Key Paper VIII: Emission Line Ratios from NIRSpec and NIRCam Wide-Field Slitless Spectroscopy at z>2
Bren E. Backhaus, Jonathan R. Trump, Nor Pirzkal +37
We use James Webb Space Telescope Near-Infrared Camera Wide Field Slitless Spectroscopy (NIRCam WFSS) and Near-Infrared spectrograph (NIRSpec) in the Cosmic Evolution Early Release…
JWST reveals a possible galaxy merger in triply-lensed MACS0647JD
Tiger Yu-Yang Hsiao, Dan Coe, Abdurro'uf +63
MACS0647JD is a triply-lensed galaxy originally discovered with the Hubble Space Telescope. Here we report new JWST imaging, which clearly resolves MACS0647JD as ha…
Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations
Jorge A. Zavala, Veronique Buat, Caitlin M. Casey +121
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-…
A Long Time Ago in a Galaxy Far, Far Away: A Candidate z ~ 12 Galaxy in Early JWST CEERS Imaging
Steven L. Finkelstein, Micaela B. Bagley, Pablo Arrabal Haro +117
We report the discovery of a candidate galaxy with a photo-z of z~12 in the first epoch of the JWST Cosmic Evolution Early Release Science (CEERS) Survey. Following conservative se…
The Physical Conditions of Emission-Line Galaxies at Cosmic Dawn from JWST/NIRSpec Spectroscopy in the SMACS 0723 Early Release Observations
Jonathan R. Trump, Pablo Arrabal Haro, Raymond C. Simons +61
We present rest-frame optical emission-line flux ratio measurements for five galaxies observed by the JWST Near-Infared Spectrograph (NIRSpec) in the SMACS 0723 Early Release…
CLEAR: The Ionization and Chemical-Enrichment Properties of Galaxies at 1.1 < z < 2.3
Casey Papovich, Raymond C. Simons, Vicente Estrada-Carpenter +15
We use deep spectroscopy from the Hubble Space Telescope (HST) Wide-Field-Camera 3 (WFC3) IR grisms combined with broad-band photometry to study the stellar populations, gas ioniza…
Spatially resolved direct method metallicity in a high-redshift analogue local galaxy: temperature structure impact on metallicity gradients
Alex J. Cameron, Tiantian Yuan, Michele Trenti +2
We investigate how HII region temperature structure assumptions affect "direct-method" spatially-resolved metallicity observations using multispecies auroral lines in a galaxy from…
Spatial Variation in Strong Line Ratios and Physical Conditions in Two Strongly-Lensed Galaxies at z~1.4
Michael K. Florian, Jane R. Rigby, Ayan Acharyya +14
For studies of galaxy formation and evolution, one of the major benefits of the James Webb Space Telescope is that space-based IFUs like those on its NIRSpec and MIRI instruments w…
Understanding Galaxy Evolution through Emission Lines
Lisa J. Kewley, David C. Nicholls, Ralph S. Sutherland
We review the use of emission-lines for understanding galaxy evolution, focusing on excitation source, metallicity, ionization parameter, ISM pressure and electron density. We show…
Theoretical ISM pressure and electron density diagnostics for local and high-redshift galaxies
Lisa J. Kewley, David C. Nicholls, Ralph S. Sutherland +4
We derive new self-consistent theoretical UV, optical, and IR diagnostics for the ISM pressure and electron density in the ionized nebulae of star-forming galaxies. Our UV diagnost…
Rest-frame UV and optical emission line diagnostics of ionised gas properties: a test case in a star-forming knot of a lensed galaxy at z~1.7
Ayan Acharyya, Lisa J. Kewley, Jane R. Rigby +7
We examine the diagnostic power of rest-frame ultraviolet (UV) nebular emission lines, and compare them to more commonly used rest-frame optical emission lines, using the test case…
Comparison of Theoretical Starburst Photoionisation Models for Optical Diagnostics
Joshua J. D'Agostino, Lisa J. Kewley, Brent Groves +5
We study and compare different examples of stellar evolutionary synthesis input parameters used to produce photoionisation model grids using the MAPPINGS V modelling code. The aim…
Calibrating Interstellar Abundances using SNR Radiative Shocks
Michael A. Dopita, Ivo R. Seitenzahl, Ralph S. Sutherland +4
Using integral field data we extract the optical spectra of shocked interstellar clouds in Kepler's supernova remnant located in the inner regions of our Galaxy, as well as in the…
IFU spectroscopy of Southern Planetary Nebulae IV: A Physical Model for IC 418
M. A. Dopita, A. Ali, R. S. Sutherland +2
We describe high spectral resolution, high dynamic range integral field spectroscopy of IC418 covering the spectral range 3300-8950Å and compare with earlier data. We determine lin…
Abundance scaling in stars, nebulae and galaxies
David C. Nicholls, Ralph S. Sutherland, Michael A. Dopita +2
We present a new basis for scaling abundances with total metallicity in nebular photoionisation models, based on extensive Milky Way stellar abundance data, to replace the uniform…
The Discovery of Raman Scattering in HII Regions
Michael A. Dopita, David C. Nicholls, Ralph S. Sutherland +2
We report here on the discovery of faint extended wings of Hα observed out to an apparent velocity of ~ 7600 km/s in the Orion Nebula (M42) and in five HII regions in the Large and…
Chemical abundances in high-redshift galaxies: A powerful new emission line diagnostic
Michael A. Dopita, Lisa J. Kewley, Ralph S. Sutherland +1
This Letter presents a new, remarkably simple diagnostic specifically designed to derive chemical abundances for high redshift galaxies. It uses only the H α, [N II] and [S II] emi…
Metal-poor dwarf galaxies in the SIGRID galaxy sample. II. The electron temperature-abundance calibration and the parameters that affect it
David C. Nicholls, Michael A. Dopita, Ralph S. Sutherland +3
In this paper, we use the Mappings photoionization code to explore the physical parameters that impact on the measurement of electron temperature and abundance in HII regions. In t…
Metal-poor dwarf galaxies in the SIGRID galaxy sample. I. HII region observations and chemical abundances
David C. Nicholls, Michael A. Dopita, Ralph S. Sutherland +3
In this paper we present the results of observations of seventeen HII regions in thirteen galaxies from the SIGRID sample of isolated gas rich irregular dwarf galaxies. The spectra…
Choirs HI Galaxy Groups: The metallicity of dwarf galaxies
Sarah M. Sweet, Michael J. Drinkwater, Gerhardt Meurer +4
We present a recalibration of the luminosity-metallicity relation for gas-rich, star-forming dwarfs to magnitudes as faint as M ~ -13. We use the Dopita et al. (2013) metallici…
Nebular metallicities in two isolated Local Void dwarf galaxies
David C. Nicholls, Helmut Jerjen, Michael A. Dopita +1
Isolated dwarf galaxies, especially those situated in voids, may provide insight into primordial conditions in the Universe and the physical processes that govern star formation in…
New Strong Line Abundance Diagnostics for \HII Regions: Effects of -Distributed Electron Energies and New Atomic Data
Michael A. Dopita, Ralph S. Sutherland, David C. Nicholls +2
Recently, \citet{Nicholls12}, inspired by \emph{in situ} observations of solar system astrophysical plasmas, suggested that the electrons in \HII regions are characterised by a …
Measuring nebular temperatures: the effect of new collision strengths with equilibrium and kappa-distributed electron energies
David C. Nicholls, Michael A. Dopita, Ralph S. Sutherland +2
In this paper we develop tools for observers to use when analysing nebular spectra for temperatures and metallicities, with two goals: to present a new, simple method to calculate…