57 hasil untuk "Pascal A. Oesch"
Menampilkan 1–20 · 0,42 detik · RSS
-
Artikel Jurnal Teks lengkap
Rapid Reionization by the Oligarchs: The Case for Massive, UV-bright, Star-forming Galaxies with High Escape Fractions
Abstract The protagonists of the last great phase transition of the universe—cosmic reionization—remain elusive. Faint star-forming galaxies are leading candidates because they are found to be numerous and may have significant ionizing photon escape fractions ( ). Here we update this picture via an…
-
Artikel Jurnal
Deep Spitzer/IRAC Data for z ∼ 10 Galaxies Reveal Blue Balmer Break Colors: Young Stellar Populations at ∼500 Myr of Cosmic Time
We present the deepest constraints yet on the median rest-UV+optical spectral energy distribution (SED) of z ∼ 10 galaxies prior to James Webb Space Telescope science operations. We constructed stacks based on four robust J _125 dropouts, previously identified across the GOODS fields. We used…
-
Artikel Jurnal
The Hα Luminosity Function of Galaxies at z ∼ 4.5
We present the H α luminosity function (LF) derived from a large sample of Lyman break galaxies at z ∼ 4.5 over the GOODS-South and North fields. This study makes use of the new, full-depth Spitzer/IRAC [3.6] and [4.5] imaging from the GOODS Re-ionization Era wide-Area Treasury from the Spitzer…
-
Artikel Jurnal
Connecting Environment, Star Formation History, and Morphology of Massive Quiescent Galaxies at 3 < z < 4 with JWST
We present the morphological properties of 17 spectroscopically confirmed massive quiescent galaxies ( $10.2\lt {\mathrm{log}}({M}_{* }/{M}_{\odot })\lt 11.2$ ) at 3.0
-
Artikel Jurnal
Exploring Cosmic Dawn with PANORAMIC. II. Cosmic Variance and Galaxy Clustering at z ∼ 10
Observational campaigns with JWST have revealed a higher-than-expected abundance of UV-bright galaxies at z ≳ 10, with various proposed theoretical explanations. A powerful complementary constraint to break degeneracies between different models is galaxy clustering. In this paper, we combine…
-
Artikel Jurnal
Spatially Resolved Properties of Galaxies at 5 < z < 9 in the SMACS 0723 JWST ERO Field
We present the first spatially resolved measurements of galaxy properties in the JWST ERO SMACS 0723 field. We perform a comprehensive analysis of five 5 < z < 9 galaxies with spectroscopic redshifts from NIRSpec observations. We perform spatially resolved spectral energy distribution fitting with…
-
Artikel Jurnal
21 Balmer Jump Street: The Nebular Continuum at High Redshift and Implications for the Bright Galaxy Problem, UV Continuum Slopes, and Early Stellar Populations
We study, from both a theoretical and observational perspective, the physical origin and spectroscopic impact of extreme nebular emission in high-redshift galaxies. The nebular continuum, which can appear during an extreme starburst, is of particular importance as it tends to redden UV slopes and…
-
Artikel Jurnal
A population of faint, old, and massive quiescent galaxies at $$3
Abstract Here we present a sample of 12 massive quiescent galaxy candidates at $$z\sim 3-4$$ z ∼ 3 - 4 observed with the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). These galaxies were pre-selected from the Hubble Space Telescope imaging and 10 of our sources were unable…
-
Artikel Jurnal
A Black Hole Star at Cosmic Noon: Extreme Balmer Break, Photospheric Continuum, and Broad Absorption by Thick Winds in a Little Red Dot at z = 1.7
Recent studies at high redshift have revealed an enigmatic class of little red dots (LRDs) with extreme Balmer breaks, stronger than in any stellar atmosphere. However, it is unclear whether such objects exist at lower redshift, especially given the low number of LRDs reported at z ≲ 2. Here, we…
-
Artikel Jurnal
Detection of [O iii]88 μm in JADES-GS-z14-0 at z = 14.1793
We report the first successful Atacama Large Millimeter/submillimeter Array (ALMA) follow-up observations of a secure z > 10 JWST-selected galaxy, by robustly detecting (6.6 σ ) the [O iii ] _88 _μ _m line in JADES-GS-z14-0 (hereafter GS-z14). The ALMA detection yields a spectroscopic redshift of z…
-
Artikel Jurnal
Exploring Cosmic Dawn with PANORAMIC. I. The Bright End of the UV Luminosity Function at z ∼ 9–17
In its first 2 yr of operation, the James Webb Space Telescope has enabled the discovery of a surprising number of UV-bright galaxies at z ∼ 10–14. Their number density is still relatively uncertain, due to cosmic variance effects, and the limited survey area with deep imaging. Here, we combine…
-
Artikel Jurnal
JWST+ALMA Reveal the Buildup of Stellar Mass in the Cores of Dusty Star-forming Galaxies at Cosmic Noon
Dusty star-forming galaxies (DSFGs) have long been suspected to serve as the missing evolutionary bridge between the star-forming and quiescent phases of massive galaxy evolution. With the combined power of JWST and the Atacama Large Millimeter/submillimeter Array (ALMA), it is now possible to use…
-
Artikel Jurnal Teks lengkap
Two Remarkably Luminous Galaxy Candidates at z ≈ 10–12 Revealed by JWST
Abstract The first few 100 Myr at z > 10 mark the last major uncharted epoch in the history of the universe, where only a single galaxy (GN-z11 at z ≈ 11) is currently spectroscopically confirmed. Here we present a search for luminous z > 10 galaxies with JWST/NIRCam photometry spanning ≈1–5 μ m…
-
Artikel Jurnal
The PANORAMIC Survey: Pure Parallel Wide Area Legacy Imaging with JWST/NIRCam
We present the PANORAMIC survey, a pure parallel extragalactic imaging program with JWST/NIRCam observed during Cycle 1. The survey obtained ∼530 square arcmin of NIRCam imaging from 1–5 μ m, totaling ∼192 hr of science integration time. This represents the largest on-sky time investment of any…
-
Artikel Jurnal
The Formation Histories of Massive and Quiescent Galaxies in the 3 < z < 4.5 Universe
We present the formation histories of 19 massive (≳3 × 10 ^10 M _⊙ ) quiescent (specific star formation rate, sSFR 3, resulting in a spectroscopically confirmed number density of ~1.4 × 10 ^−5 Mpc ^−3 between z ~ 3 and 4. Rest-frame U − V versus V − J color selections show high effectiveness in…
-
Artikel Jurnal Teks lengkap
Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys
Abstract Characterizing the prevalence and properties of faint active galactic nuclei (AGNs) in the early Universe is key for understanding the formation of supermassive black holes (SMBHs) and determining their role in cosmic reionization. We perform a spectroscopic search for broad H α emitters…
-
Artikel Jurnal
The Extreme Low-mass End of the Mass–Metallicity Relation at z ∼ 7
The mass–metallicity relation provides crucial insights into the baryon cycle in galaxies and strong constraints on galaxy formation models. We use JWST NIRSpec observations from the UNCOVER program to measure the gas-phase metallicity in a sample of eight galaxies during the epoch of reionization…
-
Artikel Jurnal
The AURORA Survey: Multiple Balmer and Paschen Emission Lines for Individual Star-forming Galaxies at z = 1.5–4.4. I. A Diversity of Nebular Attenuation Curves and Evidence for Non-unity Dust Covering Fractions
We present the nebular attenuation curves and dust covering fractions for 24 z = 1.5–4.4 star-forming galaxies using multiple Balmer and Paschen lines from the JWST/AURORA survey. Nebular reddening derived from Paschen lines exceeds that from Balmer lines for at least half the galaxies in the…
-
Artikel Jurnal
FRESCO: The Paschen-α Star-forming Sequence at Cosmic Noon
We present results from the JWST First Reionization Epoch Spectroscopically Complete Observations survey on the star-forming sequence (SFS) of galaxies at 1.0 < z < 1.7, around the peak of the cosmic star formation history. Star formation rates (SFRs) are measured from the redshifted, relatively…
-
Artikel Jurnal
Winding Back the Clock: Recent Star Formation Histories of Massive Quiescent Galaxies Are Consistent with Their Rapid Number Density Evolution since z ∼ 7
Massive quiescent galaxies have been identified out to z ∼ 7 in early JWST data, substantially exceeding (≳1 dex at z > 4) the number densities from most theoretical predictions. We investigate whether the number densities implied by the star formation histories (SFHs) of quiescent galaxies at 2 10…