Search Publications
Peering into cosmic reionization: Lyα visibility evolution from galaxies at z = 4.5-8.5 with JWST
Hu, W.; Kartaltepe, J. S.; Dickinson, M. +30 more
The resonant scattering interaction between Lyα photons and neutral hydrogen implies that a partially neutral intergalactic medium has the ability to significantly impact the detectability of Lyα emission in galaxies. Thus, the redshift evolution of the Lyα equivalent width distribution of galaxies offers a key observational probe of the degree of…
Discovery of a new N-emitter in the epoch of reionization
Schaerer, D.; Marques-Chaves, R.; Xiao, M. +1 more
We report the discovery of a compact star-forming galaxy at z = 9.380 in the GOODS-North field (named GN-z9p4), which shows numerous strong UV-optical emission lines and a single UV line, N IV] λ1486. This makes GN-z9p4 the third-highest redshift N-emitter known to date. We determined the nebular abundances of H, C, N, O and Ne, along with the siz…
1100 days in the life of the supernova 2018ibb. The best pair-instability supernova candidate, to date
Filippenko, Alexei V.; Fransson, Claes; Gromadzki, Mariusz +63 more
Stars with zero-age main sequence masses between 140 and 260 M⊙ are thought to explode as pair-instability supernovae (PISNe). During their thermonuclear runaway, PISNe can produce up to several tens of solar masses of radioactive nickel, resulting in luminous transients similar to some superluminous supernovae (SLSNe). Yet, no unambigu…
Gas-phase metallicity gradients in galaxies at z ∼ 6–8
Maiolino, R.; Castellano, M.; Pentericci, L. +18 more
The study of gas-phase metallicity and its spatial distribution at high redshift is crucial to understand the processes that shaped the growth and evolution of galaxies in the early Universe. Here we study the spatially resolved metallicity in three systems at z ∼ 6 ‑ 8, namely A2744-YD4, BDF-3299, and COSMOS24108, with JWST NIRSpec IFU low-resolu…
JADES: The emergence and evolution of Lyα emission and constraints on the intergalactic medium neutral fraction
Chevallard, Jacopo; Maseda, Michael V.; Parlanti, Eleonora +32 more
The rest-frame UV recombination emission line Lyα can be powered by ionising photons from young massive stars in star-forming galaxies, but the fact that it can be resonantly scattered by neutral gas complicates its interpretation. For reionisation-era galaxies, a neutral intergalactic medium will scatter Lyα from the line of sight, making Lyα a u…
New AGN diagnostic diagrams based on the [OIII]λ4363 auroral line
Feltre, Anna; Übler, Hannah; D'Eugenio, Francesco +8 more
The James Webb Space Telescope (JWST) is revolutionizing our understanding of black hole formation and growth in the early Universe. However, JWST has also revealed that some of the classical diagnostics, such as the Baldwin, Phillips & Terlevich (BPT) diagrams and X-ray emission, often fail to identify active galactic nuclei (AGN) at high red…
X-Shooting ULLYSES: Massive stars at low metallicity. III. Terminal wind speeds of ULLYSES massive stars
Crowther, P. A.; Herrero, A.; Hamann, W. -R. +26 more
Context. The winds of massive stars have a significant impact on stellar evolution and on the surrounding medium. The maximum speed reached by these outflows, the terminal wind speed v∞, is a global wind parameter and an essential input for models of stellar atmospheres and feedback. With the arrival of the ULLYSES programme, a legacy U…
Cosmography with supernova Refsdal through time-delay cluster lensing: Independent measurements of the Hubble constant and geometry of the Universe
Pagano, L.; Grillo, C.; Rosati, P. +1 more
We present new measurements of the values of the Hubble constant, matter density, dark energy density, and dark energy density equation-of-state (EoS) parameters. These results have been obtained from a full strong-lensing analysis of the observed positions of 89 multiple images and 4 measured time delays of the supernova (SN) Refsdal in the Hubbl…
Outshining in the spatially resolved analysis of a strongly lensed galaxy at z = 6.072 with JWST NIRCam
Magdis, G. E.; Laporte, N.; Mason, C. A. +19 more
We present JWST/NIRCam observations of a strongly lensed, sub-L*, multiply imaged galaxy at z = 6.072, with magnification factors µ ≳ 20 across the galaxy. The galaxy has rich HST, MUSE, and ALMA ancillary observations across a broad wavelength range. Aiming to quantify the reliability of stellar mass estimates of high redshift ga…
Discovery of a variable energy-dependent X-ray polarization in the accreting neutron star GX 5−1
Kaaret, Philip; Wu, Kinwah; Steiner, James F. +116 more
We report on the coordinated observations of the neutron star low-mass X-ray binary (NS-LMXB) GX 5−1 in X-rays (IXPE, NICER, NuSTAR, and INTEGRAL), optical (REM and LCO), near-infrared (REM), mid-infrared (VLT VISIR), and radio (ATCA). This Z-source was observed by IXPE twice in March-April 2023 (Obs. 1 and 2). In the radio band the source was det…