Ivo Labbe
Among the most remarkable results from JWST is the discovery of abundant, compact, and very red sources in the early Universe known as "Little Red Dots" (LRDs). The relative degree to which starlight and active galactic nuclei (AGN) drive…
JWST data have enabled the abundant identification of compact broad Balmer line sources nicknamed the Little Red Dots. While they share broad lines with active galactic nuclei, they are unusually X-ray and infrared weak. We investigate the…
While the size-mass relation provides insight into the structural evolution of galaxies, the data available and methods employed have hindered our ability to study a detailed and comprehensive description of this key relation across cosmic…
We present spectrally-resolved structural parameter measurements of 29,608 sources from the legacy lensing field of Abell 2744, quantifying global structures from observed $0.7 \mu m - 4.8 \mu m$ and spanning rest-frame UV to NIR at…
We present 3D-Herschel, a new 0.3-350$\mu$m photometric catalog that combines deblended Herschel far-infrared (FIR) imaging with the CANDELS/3D-HST legacy fields to probe the dust-obscured universe. Using the 17-parameter fitting code…
We constrain the nebular attenuation curve and investigate dust geometry in star-forming galaxies at cosmic noon using photometric medium-band emission line measurements. We measure H-alpha emission line fluxes for a sample of 209…
We present the discovery of a strongly lensed galaxy at $z\sim11-12$, dubbed the ``Misty Moons'', identified in the JWST Treasury Survey, Vast Exploration for Nascent, Unexplored Sources (VENUS). The Misty Moons is gravitationally lensed by…
Little red dots (LRDs) are an abundant population of compact high-redshift sources with red rest-frame optical continua, discovered by the James Webb Space Telescope (JWST). Their red colors and power sources have been attributed either to…
We report a revised spectroscopic redshift for the dusty massive galaxy S1, previously inferred with an exceptionally high baryon-to-star conversion efficiency from NIRCam slitless grism data at $z_{\rm grism}=5.58$. Our new JWST/NIRSpec…
We present the number density of massive ($ \mathrm{ log (M_{*}/M_{\odot}) > 10.3} $) quiescent galaxies at $2<z<5$ using JWST NIRSpec PRISM spectra. This work relies on spectra from RUBIES, which provides excellent data quality and an…
JWST has revealed a stunning population of bright galaxies at surprisingly early epochs, $z>10$, where few such sources were expected. Here we present the most distant example of this class yet -- MoM-z14, a luminous ($M_{\rm{UV}}=-20.2$)…
Star formation timescales are key to understanding fundamental physics like feedback mechanisms, as well as the abundance of bright galaxies at $z>10$. We investigate galaxy star formation histories (SFHs) and their evolution across…
"Little red dots" (LRDs) represent a new population of astronomical objects uncovered by JWST whose nature remains debated. Although many LRDs are suspected as active galactic nuclei (AGN), they show little variability on days-years…
The correlation between galaxy stellar mass and gas-phase metallicity, known as the mass-metallicity relation (MZR), gives key insights into the processes that govern galaxy evolution. However, unquantified observational and selection…
We use the DAWN JWST Archive to construct and characterise a sample of 116 little red dots (LRDs) across 2.3<z<9.3, selecting all sources with v-shaped UV-optical continua from NIRSpec/PRISM spectra and compact morphologies in NIRCam/F444W…
At low redshift, massive quiescent galaxies (MQGs) are most frequently found in massive, rich galaxy clusters, but at high redshift the trend is less clear. Here, we present spectroscopic evidence of the effects of environment on the…
We report the discovery of two z ~ 12 galaxy candidates with unusually red UV slopes (betaUV ~> -1.5), and probe the origin of such colors at cosmic dawn. From Prospector fits to the UNCOVER/MegaScience dataset -- deep JWST/NIRCam imaging…
The origin of the rest-optical emission of compact, red, high-redshift sources known as `little red dots' (LRDs) poses a major puzzle. If interpreted as starlight, it would imply that LRDs would constitute the densest stellar systems in the…
New populations of red active galactic nuclei (known as ``Little Red Dots'') discovered by JWST exhibit remarkable spectral energy distributions. Leveraging X-ray through far-infrared observations of two of the most luminous known Little…
One of the most surprising results of early James Webb Space Telescope (JWST) observations is the discovery of an abundance of red, compact, broad-line objects dubbed "little red dots" (LRDs) at $z>4$. Their spatial density…