The JWST Early Release Observations

Pontoppidan, K. M.; Blome, Claire; Braun, Hannah; Brown, Matthew A.; Carruthers, Margaret; Coe, Dan; DePasquale, Joseph; Espinoza, N.; Marín, Macarena García; Henry, Alaina; Hustak, Leah; James, Andi; Koekemoer, Anton M.; LaMassa, Stephanie; Law, David R.; Lockwood, A.; Moro‐Martín, Amaya; Mullally, Susan E.; Pagan, Alyssa; Player, Dani; Proffitt, Charles; Pulliam, Christine; Ramsay, Leah; Ravindranath, Swara; Reid, Neill; Robberto, M.; Sabbi, E.; Úbeda, Leonardo

doi:10.48550/arxiv.2207.13067

Cited by 17 publications

(20 citation statements)

References 32 publications

(31 reference statements)

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“…The data we use for this analysis originates from the Early Release Observations of SMACS 0723 (Pontoppidan et al 2022) and include observations taken with the Near Infrared Camera (NIRCam; Rieke et al 2005Rieke et al , 2008Rieke et al , 2015. The images were obtained on June 06, 2022 (PI: Pontoppidan; Program ID 2736) in the F090W, F150W, and F200W short-wavelength (SW) bands, and F356W, F277W, and F444W long-wavelength (LW) bands.…”

Section: Data Reduction and Productsmentioning

confidence: 99%

Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at $z > 3$ with JWST in the SMACS 0723 Field

Ferreira¹,

Adams²,

Conselice³

et al. 2022

Preprint

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We present early results regarding the morphological and structural properties of galaxies seen with the James Webb Space Telescope at z > 3 in the Early Release Observations of SMACS 0723, a galaxy cluster at z = 0.39. We investigate, for the first time, the optical morphologies of a significant number of z > 3 galaxies with accurate photometric redshifts in this field to determine the form of galaxy structure in the relatively early universe. We use visual morphologies and Morfometryka measures to perform quantitative morphology measurements, both parametric with light profile fitting (Sérsic indices) and non-parametric (CAS values). Using these, we measure the relative fraction of disk, spheroidal, and peculiar galaxies at 3 < z < 8. We discover the surprising result that at z > 1.5 disk galaxies dominate the overall fraction of morphologies, with a factor of ∼ 10 relative higher number of disk galaxies than seen by the Hubble Space Telescope at these redshifts. Our visual morphological estimates of galaxies align closely with their locations in CAS parameter space and their Sérsic indices.

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Section: Data Reduction and Productsmentioning

confidence: 99%

Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at $z > 3$ with JWST in the SMACS 0723 Field

Ferreira¹,

Adams²,

Conselice³

et al. 2022

Preprint

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“…We use data from JWST NIRSpec Micro-Shutter Assembly (MSA) observations of the SMACSJ0723.3-7327 galaxy cluster taken on 2022 Jun 30, as part of the public ERO data release (Program ID 2736, PI: K. Pontoppidan, Pontoppidan et al 2022). The 0.2 × 0.46 MSA shutters are configurable and can be used to acquire spectra of hundreds of sources in a single field-of-view (Ferruit et al 2022).…”

Section: Data and Emission Line Fittingmentioning

confidence: 99%

First Insights into the ISM at $z>8$ with JWST: Possible Physical Implications of a High [O III]$\mathbf{λ4363}$/[O III]$\mathbf{λ5007}$

Katz¹,

Saxena²,

Cameron³

et al. 2022

Preprint

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We present a detailed analysis of the rest-frame optical emission line ratios for three spectroscopically confirmed galaxies at 𝑧 > 7.5. The galaxies were identified in the James Webb Space Telescope (JWST) Early Release Observations field SMACS J0723.3−7327. By quantitatively comparing Balmer and oxygen line ratios of these galaxies with various low-redshift "analogue" populations (e.g. Green Peas, Blueberries, etc.), we show that no single analogue population captures the diversity of line ratios of all three galaxies observed at 𝑧 > 7.5. We find that S06355 at 𝑧 = 7.67 and S10612 at 𝑧 = 7.66 are similar to local Green Peas and Blueberries. In contrast, S04590 at 𝑧 = 8.50 appears to be significantly different from the other two galaxies, most resembling extremely low-metallicity systems in the local Universe. Perhaps the most striking spectral feature in S04590 is the curiously high [O III] 𝜆4363/[O III] 𝜆5007 ratio (RO3) of 0.047 (or 0.059 when dust-corrected), implying either extremely high electron temperatures, > 3 × 10 4 K, or gas densities > 10 4 cm −3 . Observed line ratios indicate that this galaxy is unlikely to host an AGN. Using photoionization modelling, we show that the inclusion of high-mass X-ray binaries or a high cosmic ray background in addition to a young, low-metallicity stellar population can provide the additional heating necessary to explain the observed high RO3 while remaining consistent with other observed line ratios. Our models represent a first step at accurately characterising the dominant sources of photoionization and heating at very high redshifts, demonstrating that non-thermal processes may become important as we probe deeper into the Epoch of Reionization.

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“…The ratios Fe/Si and Mg/Si can place constraints on the size of a rocky planet's core or the composition of its mantle (Dorn et al 2017, Unterborn & Panero 2017, while volatile abundances (C, N, O) enable comparisons of stellar to planetary C/O and N/O which can hint at the formation locations of gaseous planets ( Öberg et al 2011, Mordasini et al 2016, MacDonald & Madhusudhan 2017. JWST has already begun to conduct its first observations of the atmospheres of other worlds, making a uniform determination of their host star abundances an important and timely step in the interpretation of those results (Pontoppidan et al 2022).…”

Section: Introductionmentioning

confidence: 99%

Chemical Abundances for 25 JWST Exoplanet Host Stars with KeckSpec

et al. 2022

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Using a data-driven machine learning tool we report T eff, log ( g ) , v sin ( i ) , and elemental abundances for 15 elements (C, N, O, Na, Mg, Al, Si, Ca, Ti, V, Cr, Mn, Fe, Ni, Y) for a sample of 25 exoplanet host stars targeted by JWST's first year of observations. The chemical diversity of these stars show that, while a number of their companion planets may have formed in a disk with chemistry similar to Solar, some JWST targets likely experienced different disk compositions. This sample is part of a larger forthcoming catalog that will report homogeneous abundances of ∼4500 FGK stars derived from Keck/HIRES optical spectra.

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The JWST Early Release Observations

Cited by 17 publications

References 32 publications

Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at $z > 3$ with JWST in the SMACS 0723 Field

Panic! At the Disks: First Rest-frame Optical Observations of Galaxy Structure at $z > 3$ with JWST in the SMACS 0723 Field

First Insights into the ISM at $z>8$ with JWST: Possible Physical Implications of a High [O III]$\mathbf{λ4363}$/[O III]$\mathbf{λ5007}$

Chemical Abundances for 25 JWST Exoplanet Host Stars with KeckSpec

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