Search Publications
Ubiquitous broad-line emission and the relation between ionized gas outflows and Lyman continuum escape in Green Pea galaxies
Chisholm, J.; Schaerer, D.; Marques-Chaves, R. +29 more
We report observational evidence of highly turbulent ionized gas kinematics in a sample of 20 Lyman continuum (LyC) emitters (LCEs) at low redshift (z ∼ 0.3). Detailed Gaussian modeling of optical emission line profiles in high-dispersion spectra consistently shows that both bright recombination and collisionally excited lines can be fitted as one…
The CO-to-H2 conversion factor of molecular outflows. Rovibrational CO emission in NGC 3256-S resolved by JWST/NIRSpec
Rigopoulou, D.; García-Burillo, S.; González-Alfonso, E. +2 more
We analyze JWST/NIRSpec observations of the CO rovibrational υ = 1−0 band at ~4.67 µm around the dust-embedded southern active galactic nucleus (AGN) of NGC 3256 (d = 40 Mpc; LIR = 1011.6 L⊙). We classify the CO υ = 1−0 spectra into three categories based on the behavior of P- and R-branches of the band: (a) both b…
Lyman continuum leaker candidates at z ∼ 3-4 in the HDUV based on a spectroscopic sample of MUSE LAEs
Oesch, P. A.; Illingworth, G. D.; Verhamme, A. +15 more
Context. In recent years, a number of Lyman continuum (LyC) leaker candidates have been found at intermediate redshifts, providing insight into how the Universe was reionised at early cosmic times. There are now around 100 known LyC leakers at all redshifts, which enables us to analyse their properties statistically.
Aims: Here, we identify n…
Evidence for inflows and outflows in the nearby black hole transient Swift J1727.8−162
Armas Padilla, M.; Mata Sánchez, D.; Muñoz-Darias, T. +2 more
We present 20 epochs of optical spectroscopy obtained with the GTC-10.4m telescope across the bright discovery outburst of the black hole candidate Swift J1727.8−162. The spectra cover the main accretion states and are characterised by the presence of hydrogen and helium emission lines, commonly observed in these objects. They show complex profile…
THEMIS 2.0: A self-consistent model for dust extinction, emission, and polarisation
Miville-Deschênes, M. -A.; Ysard, N.; Guillet, V. +6 more
Context. Recent observational constraints in emission, extinction, and polarisation have at least partially invalidated most of the astronomical standard grain models for the diffuse interstellar medium. Moreover, laboratory measurements on interstellar silicate analogues have shown quite significant differences with the optical properties used in…
The ALMA-CRISTAL survey: Widespread dust-obscured star formation in typical star-forming galaxies at z = 4–6
Übler, Hannah; Ferrara, Andrea; Fisher, Deanne B. +29 more
We present the morphological parameters and global properties of dust-obscured star formation in typical star-forming galaxies at z = 4–6. Among 26 galaxies composed of 20 galaxies observed by the Cycle-8 ALMA Large Program, CRISTAL, and 6 galaxies from archival data, we individually detect rest-frame 158 µm dust continuum emission from 19 g…
A Walk on the Retrograde Side (WRS) project. I. Tidying-up the retrograde halo with high-resolution spectroscopy
Ilyin, I.; Lardo, C.; Massari, D. +7 more
Relics of ancient accretion events experienced by the Milky Way are predominantly located within the stellar halo of our Galaxy. However, debris from different objects display overlapping distributions in dynamical spaces, making it extremely challenging to properly disentangle their contribution to the build-up of the Galaxy. To shed light on thi…
Modeling the molecular gas content and CO-to-H2 conversion factors in low-metallicity star-forming dwarf galaxies
Ramambason, L.; Lebouteiller, V.; Madden, S. C. +8 more
Context. Low-metallicity dwarf galaxies often show no or little CO emission, despite the intense star formation observed in local samples. Both simulations and resolved observations indicate that molecular gas in low-metallicity galaxies may reside in small dense clumps, surrounded by a substantial amount of more diffuse gas that is not traced by …
Classification and parameterization of a large Gaia sample of white dwarfs using XP spectra
Jordan, S.; Barstow, M. A.; Bergeron, P. +3 more
Context. The latest Gaia data release in July 2022, DR3, in addition to the refinement of the astrometric and photometric parameters from DR2, added a number of important data products to those available in earlier releases, including radial velocity data, information on stellar multiplicity, and XP spectra of a selected sample of stars. Gaia has …
Discovery of the local counterpart of disc galaxies at z > 4: The oldest thin disc of the Milky Way using Gaia-RVS
Guiglion, G.; Chiappini, C.; Queiroz, A. B. +5 more
Context. JWST recently detected numerous disc galaxies at high redshifts, and there have been observations of cold disc galaxies at z > 4 with ALMA. In the Milky Way (MW), recent studies highlight the presence of metal-poor stars in cold-disc orbits, suggesting an ancient disc. This prompts two fundamental questions. The first refers to the tim…