Tobias J. Looser
A5057710598- 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
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- CCD and CMOS Imaging Sensors
- Spectroscopy and Laser Applications
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Black Holes and Theoretical Physics
- History and Developments in Astronomy
- Astro and Planetary Science
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Photocathodes and Microchannel Plates
- Real-time simulation and control systems
- Advanced Statistical Methods and Models
- Advanced Measurement and Metrology Techniques
- Advanced Optical Sensing Technologies
- Spectroscopy and Chemometric Analyses
University of Cambridge
2021-2025
Mount Stromlo Observatory
2024
ACT Government
2024
ARC Centre of Excellence for All-sky Astrophysics
2023
ASTRO-3D
2023
Space Telescope Science Institute
2022
ETH Zurich
2021
We present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous candidate z > 10 Lyman break galaxy in GOODS-North field with M UV = −21.5. derive a redshift 10.603 (lower than previous determinations) based on multiple emission lines our low and medium resolution spectra over 0.7 − 5.3 μm. significantly detect continuum measure blue rest-UV spectral slope β −2.4. Remarkably, we see spatially extended Lyman- α (despite highly neutral intergalactic expected at this early epoch),...
We analyse the chemical properties of three z~8 galaxies behind galaxy cluster SMACS J0723.3-7327, observed as part Early Release Observations programme James Webb Space Telescope (JWST). Exploiting [O III]4363 auroral line detections in NIRSpec spectra, we robustly apply direct Te method for very first time at such high redshift, measuring metallicities ranging from extremely metal poor (12+log(O/H)~7) to about one-third solar. also discuss excitation these sources, and compare them with...
Several theories have been proposed to describe the formation of black hole seeds in early Universe and explain emergence very massive holes observed first thousand million years after Big Bang
We present JWST NIRCam 9-band near-infrared imaging of the luminous $z=10.6$ galaxy GN-z11 from Advanced Deep Extragalactic Survey (JADES) GOODS-N field. find a spectral energy distribution (SED) entirely consistent with expected form high-redshift galaxy: clear blue continuum 1.5 to 4 microns complete dropout in F115W. The core is extremely compact imaging. analyze image two-component model, using point source and S\'{e}rsic profile that fits half-light radius 200 pc an index $n=0.9$....
Abstract JWST has revolutionized the field of extragalactic astronomy with its sensitive and high-resolution infrared view distant Universe. Adding to new legacy observations, we present first NIRCam imaging data release from Advanced Deep Extragalactic Survey (JADES), providing nine filters ∼25 arcmin 2 covering Hubble Ultra Field portions Great Observatories Origins South. Utilizing 87 on-sky dual-filter hours exposure time, these images reveal deepest ever near-infrared this iconic field....
ABSTRACT We present an interstellar medium and stellar population analysis of three spectroscopically confirmed z > 7 galaxies in the Early Release Observations JWST/NIRCam JWST/NIRSpec data SMACS J0723.3−7327 cluster. use Bayesian spectral energy distribution-fitting code prospector with a flexible star formation history (SFH), variable dust attenuation law, self-consistent model nebular emission (continuum lines). Importantly, we self-consistently fit both line fluxes from...
We present emission-line ratios from a sample of 27 Lyman-break galaxies z ∼ 5.5 − 9.5 with −17.0 < M 1500 −20.4, measured ultra-deep JWST/NIRSpec multi-object spectroscopy the JWST Advanced Deep Extragalactic Survey (JADES). used combination 28 h deep PRISM/CLEAR and 7 G 395 / F 290 LP observations to measure, or place strong constraints on, widely studied rest-frame optical emission lines including H α , β [O II ] λλ 3726, 3729, [Ne III λ 3869, 4959, 5007, I 6300, [N 6583, [S 6716, 6731...
We analysed the gas-phase metallicity properties of a sample low-stellar-mass (log M ⋆ / ⊙ ≲ 9) galaxies at 3 < z 10 observed with JWST/NIRSpec as part JADES programme in its deep GOODS-S tier. By combining this more massive similar redshifts from other programmes, we study scaling relations between stellar mass ( ), oxygen abundance (O/H), and star-formation rate (SFR) for 146 spanning three orders magnitude out to epoch early galaxy assembly. find evidence shallower slope low-mass end...
Abstract We present a catalog of 717 candidate galaxies at z > 8 selected from 125 square arcmin NIRCam imaging as part the JWST Advanced Deep Extragalactic Survey (JADES). combine full JADES data set with Medium and First Reionization Epoch Spectroscopic COmplete (FRESCO) along extremely deep existing observations Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) final filter that includes 15 JWST/NIRCam filters five HST/ACS filters. The high-redshift galaxy candidates were...
We present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous candidate $z>10$ Lyman break galaxy in GOODS-North field with $M_{UV}=-21.5$. derive a redshift $z=10.603$ (lower than previous determinations) based on multiple emission lines our low and medium resolution spectra over $0.8-5.3 μ$m. significantly detect continuum measure blue rest-UV spectral slope $β=-2.4$. Remarkably, we see spatially-extended Lyman-$α$ (despite highly-neutral IGM expected at this early epoch),...
We present an overview of the James Webb Space Telescope (JWST) Advanced Deep Extragalactic Survey (JADES), ambitious program infrared imaging and spectroscopy in GOODS-S GOODS-N deep fields, designed to study galaxy evolution from high redshift cosmic noon. JADES uses about 770 hours Cycle 1 guaranteed time largely Near-Infrared Camera (NIRCam) Spectrograph (NIRSpec) instrument teams. In GOODS-S, around Hubble Ultra Field Chandra South, produces a region ~45 arcmin$^2$ with average 130 hrs...
We present the properties of 17 faint Lyman- α emitting galaxies (LAEs) at z > 5.8 from JWST Advanced Deep Extragalactic Survey (JADES) spectroscopic data in Hubble Ultra Field/GOODS-S. These LAEs span a redshift range ≈ − 8.0 and UV magnitude M −17 to −20.6, with Ly equivalent width (EW) ≈25 350 Å. The detection other rest-optical emission lines spectra these enables determination accurate systemic redshifts velocity offsets, as well physical chemical composition their stars interstellar...
Abstract Local and low-redshift ( z < 3) galaxies are known to broadly follow a bimodal distribution: actively star-forming with relatively stable star-formation rates passive systems. These two populations connected by in slow transition. By contrast, theory predicts that star formation was stochastic at early cosmic times low-mass systems 1–4 . transitioned rapidly between starburst episodes phases of suppressed formation, potentially even causing temporary quiescence—so-called...
ABSTRACT Reionization is thought to be driven by faint star-forming galaxies, but characterizing this population has long remained very challenging. Here, we utilize deep nine-band JADES (JWST Advanced Deep Extragalactic Survey)/NIRCam (Near-Infrared Camera) imaging study the and ionizing properties of 756 $z\sim 6-9$ including hundreds ultraviolet (UV)-faint objects ($M_\mathrm{UV}\gt -18$). The faintest ($m\sim 30$) galaxies in our sample typically have stellar masses $M_\ast \sim...
Finding the first generation of stars formed out pristine gas in early Universe, known as Population III (PopIII) stars, is one most important goals modern astrophysics. Recent models have suggested that PopIII may form pockets halo more evolved galaxies. We present NIRSpec integral field spectroscopy and micro-shutter array spectroscopic observations region around GN-z11, an exceptionally luminous galaxy at z = 10.6, reveal a greater than 5 σ detection feature consistent with being HeII λ...
The rest-frame UV recombination emission line Ly α can be powered by ionising photons from young massive stars in star-forming galaxies, but the fact that it resonantly scattered neutral gas complicates its interpretation. For reionisation-era a intergalactic medium will scatter of sight, making useful probe fraction evolution. Here, we explore JWST/NIRSpec spectra ongoing JADES programme, which targets hundreds galaxies well-studied GOODS-S and GOODS-N fields. These sources are UV-faint...
Abstract We report the discovery of an extreme galaxy overdensity at z = 5.4 in GOODS-S field using James Webb Space Telescope (JWST)/NIRCam imaging from JADES and JEMS alongside JWST/NIRCam wide-field slitless spectroscopy FRESCO. identified potential members Hubble Telescope+JWST photometry spanning λ 0.4–5.0 μ m. These data provide accurate well-constrained photometric redshifts down to m ≈ 29–30 mag. subsequently confirmed N 81 galaxies 5.2 < 5.5 JWST over 3.9–5.0 through a targeted...
Finding the emergence of first metals in early Universe and identifying their origin are some most important goals modern astrophysics. We present deep JWST/NIRSpec spectroscopy GS-z12, a galaxy at z = 12.5, which we report detection C III ] λλ 1907,1909 nebular emission line. This represents distant metal transition, redshift determination based on lines. In addition, tentative detections [O II 3726,3729 [Ne λ 3869, possibly O 1661,1666. By using accurate obtained from ], can model Ly α...
Abstract We present the third data release of JWST Advanced Deep Extragalactic Survey (JADES), providing both imaging and spectroscopy in two GOODS fields. Spectroscopy consists medium-depth deep NIRSpec/microshutter assembly spectra 4000 targets, covering spectral range 0.6–5.3 μ m observed with low-dispersion prism ( R = 30–300) all three medium-resolution gratings 500–1500). describe observations, reduction, sample selection, target allocation. measured 2375 redshifts (2053 from multiple...
Abstract While JWST has observed galaxies assembling as early z ∼ 14, evidence of with significant old stellar populations in the Epoch Reionisation (EoR) – descendants these earliest are few and far between. Bursty star-formation histories (SFHs) have been invoked to explain detectability UV-bright galaxies, but also interpret showing Balmer breaks without nebular emission lines. We present first spectroscopic a 7.9 galaxy, A2744-YD4, which shows break lines, indicating presence both mature...
We present a detailed analysis of the rest-frame optical emission line ratios for three spectroscopically confirmed galaxies at $z>7.5$. The were identified in James Webb Space Telescope (JWST) Early Release Observations field SMACS J0723.3$-$7327. By quantitatively comparing Balmer and oxygen these with various low-redshift "analogue" populations (e.g. Green Peas, Blueberries, etc.), we show that no single analogue population captures diversity all observed find S06355 $z=7.67$ S10612...
Multiple theories have been proposed to describe the formation of black hole seeds in early Universe and explain emergence very massive holes observed first billion years after Big Bang. Models consider different seeding accretion scenarios, which require detection characterisation few hundred million Bang be validated. Here we present an extensive analysis JWST-NIRSpec spectrum GN-z11, exceptionally luminous galaxy at z=10.6, revealing [NeIV]2423 CII*1335 transitions (typical Active...
Large dust reservoirs (up to $\sim 10^8 \, \mathrm{M_\odot}$) have been detected in galaxies out redshift $z \sim 8$, when the age of universe was only about 600 Myr. Generating significant amounts within such a short timescale has proven challenging for theories formation and prompted revision modelling potential sites production as atmospheres asymptotic giant branch (AGB) stars low-metallicity environments, supernovae (SNe) ejecta, accelerated growth grains interstellar medium (ISM)....