Search Publications
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…
Beyond Gaia DR3: Tracing the [α/M] - [M/H] bimodality from the inner to the outer Milky Way disc with Gaia-RVS and convolutional neural networks
Guiglion, G.; Fabbro, S.; Valentini, M. +17 more
Context. In June 2022, Gaia DR3 provided the astronomy community with about one million spectra from the Radial Velocity Spectrometer (RVS) covering the CaII triplet region. In the next Gaia data releases, we anticipate the number of RVS spectra to successively increase from several 10 million spectra to eventually more than 200 million spectra. T…
PDRs4All. II. JWST's NIR and MIR imaging view of the Orion Nebula
Hartigan, Patrick; Zhang, Yong; Gordon, Karl D. +139 more
Context. The James Webb Space Telescope (JWST) has captured the most detailed and sharpest infrared (IR) images ever taken of the inner region of the Orion Nebula, the nearest massive star formation region, and a prototypical highly irradiated dense photo-dissociation region (PDR).
Aims: We investigate the fundamental interaction of far-ultra…