Search Publications
The missing light of the Hubble Ultra Deep Field
Borlaff, Alejandro; Eliche-Moral, M. Carmen; Beckman, John E. +11 more
Context. The Hubble Ultra Deep field (HUDF) is the deepest region ever observed with the Hubble Space Telescope. With the main objective of unveiling the nature of galaxies up to z ∼ 7 - 8, the observing and reduction strategy have focused on the properties of small and unresolved objects, rather than the outskirts of the largest objects, which ar…
A census of massive stars in NGC 346. Stellar parameters and rotational velocities
Dufton, P. L.; Lennon, D. J.; Evans, C. J. +2 more
Spectroscopy for 247 stars towards the young cluster NGC 346 in the Small Magellanic Cloud has been combined with that for 116 targets from the VLT-FLAMES Survey of Massive Stars. Spectral classification yields a sample of 47 O-type and 287 B-type spectra, while radial-velocity variations and/or spectral multiplicity have been used to identify 45 …
HST spectra reveal accretion in MY Lupi
France, K.; Alcalá, J. M.; Manara, C. F. +5 more
The mass accretion rate is a crucial parameter for the study of the evolution of accretion discs around young low-mass stellar and substellar objects (YSOs). We revisit the case of MY Lup, an object where VLT/X-shooter data suggested a negligible mass accretion rate, and show it to be accreting on a level similar to other Class II YSOs in Lupus ba…
Multiphase quasar-driven outflows in PG 1114+445. I. Entrained ultra-fast outflows
Piconcelli, Enrico; Tombesi, Francesco; Serafinelli, Roberto +3 more
Substantial evidence in the last few decades suggests that outflows from supermassive black holes (SMBH) may play a significant role in the evolution of galaxies. These outflows, powered by active galactic nuclei (AGN), are thought to be the fundamental mechanism by which the SMBH transfers a significant fraction of its accretion energy to the sur…
The most luminous blue quasars at 3.0 < z < 3.3. I. A tale of two X-ray populations
Marconi, A.; Vignali, C.; Gilli, R. +8 more
We present the X-ray analysis of 30 luminous quasars at z ≃ 3.0 - 3.3 with pointed XMM-Newton observations (28-48 ks) originally obtained by our group to test the suitability of active galactic nuclei as standard candles for cosmological studies. The sample was selected in the optical from the Sloan Digital Sky Survey Data Release 7 to be represen…
Massive galaxies on the road to quenching: ALMA observations of powerful high redshift radio galaxies
Lehnert, Matthew D.; De Breuck, Carlos; Wylezalek, Dominika +10 more
We present 0.″3 (band 6) and 1.″5 (band 3) ALMA observations of the (sub)millimeter dust continuum emission for 25 radio galaxies at 1 < z < 5.2. Our survey reaches a rms flux density of ∼50 µJy in band 6 (200-250 GHz) and ∼20 µJy in band 3 (100-130 GHz). This is an order of magnitude deeper than single-dish 850 µm observat…
Gaia Data Release 2. All-sky classification of high-amplitude pulsating stars
Szabados, L.; Audard, M.; Plachy, E. +23 more
Context. More than half a million of the 1.69 billion sources in Gaia Data Release 2 (DR2) are published with photometric time series that exhibit light variations during the 22 months of observation.
Aims: An all-sky classification of common high-amplitude pulsators (Cepheids, long-period variables, δ Scuti/SX Phoenicis, and RR Lyrae stars) …
Abundances and kinematics of carbon-enhanced metal-poor stars in the Galactic halo. A new classification scheme based on Sr and Ba
Hansen, C. J.; Nordström, B.; Andersen, J. +4 more
Carbon-enhanced metal-poor (CEMP) stars span a wide range of stellar populations, from bona fide second-generation stars to later-forming stars that provide excellent probes of binary mass transfer and stellar evolution. Here we analyse 11 metal-poor stars (8 of which are new to the literature), and demonstrate that 10 are CEMP stars. Based on hig…
The bimodal [Mg/Fe] versus [Fe/H] bulge sequence as revealed by APOGEE DR14
Schultheis, M.; Minniti, D.; Recio-Blanco, A. +5 more
Context. The Galactic bulge has a bimodal metallicity distribution function: different kinematic, spatial, and, potentially, age distributions characterize the metal-poor and metal-rich components. Despite this observed dichotomy, which argues for different formation channels for those stars, the distribution of bulge stars in the α-abundance vers…
Aliphatic and aromatic hydrocarbons in comet 67P/Churyumov-Gerasimenko seen by ROSINA
Altwegg, K.; Balsiger, H.; Fuselier, S. A. +10 more
Context. Unlike all previous cometary space missions, the Rosetta spacecraft accompanied its target, comet 67P/Churyumov-Gerasimenko, for more than two years on its way around the Sun. Thereby, an unexpected diversity and complexity of the chemical composition was revealed.
Aims: Our first step of decrypting the exact chemical composition of …