Search Publications
Star formation in extreme environments: A 200 pc high velocity gas stream in the Galactic centre
Menten, K. M.; Schilke, P.; Fuller, G. A. +9 more
Context. The expanding molecular ring (EMR) manifests itself as a parallelogram in the position-velocity diagram of spectral line emission from the Central Molecular Zone (CMZ) surrounding the Galactic centre (GC). It is a high velocity (| VLSR | > 100 km s‑1) extended molecular gas structure. The formation of the EMR is b…
Atmospheric properties of AF Lep b with forward modeling
Tremblin, P.; De Rosa, R. J.; Boccaletti, A. +11 more
Context. About a year ago, a super-Jovian planet was directly imaged around the nearby young solar-type star AF Lep. The 2.8 MJup planet orbiting at a semimajor axis of 8.2 au matches the predicted location based on the HIPPARCOS-Gaia astrometric acceleration.
Aims: Our aim is to expand the atmospheric exploration of AF Lep b by mo…
High-resolution spectroscopy of the young open cluster M 39 (NGC 7092)
Vallenari, A.; Bragaglia, A.; Frasca, A. +5 more
M 39 is a nearby young open cluster hardly studied in the last few decades. No giant is known among its members and its chemical composition has never been studied. In order to investigate it, we performed high-resolution spectroscopy of 20 expected cluster members with the HARPS and FIES spectrographs. By combining our observations with archival …
An in-depth analysis of the differentially expanding star cluster Stock 18 (Villafranca O-036) using Gaia DR3 and ground-based data
Maíz Apellániz, J.; Sota, A.; Pantaleoni González, M. +4 more
Context. The Villafranca project is combining Gaia data with ground-based surveys to analyze Galactic stellar groups (clusters, associations, or parts thereof) with OB stars. Aims. We want to analyze the poorly studied cluster Stock 18 within the Villafranca project, as it is a very young stellar cluster with a symmetrical and compact H II region …
Recurring tidal disruption events a decade apart in IRAS F01004-2237
Buckley, David; Fan, Xiaohui; Gromadzki, Mariusz +16 more
Context. In theory, recurring tidal disruption events (TDEs) may occur when a close stellar binary encounters a supermassive black hole, if one star is captured and undergoes repeating partial TDEs, or if both stars are tidally disrupted (double TDEs). In addition, independent TDEs may be observed over decades in some special galaxies where the TD…
Investigating episodic mass loss in evolved massive stars: II. Physical properties of red supergiants at subsolar metallicity
Zapartas, E.; Munoz-Sanchez, G.; de Wit, S. +8 more
Mass loss during the red supergiant (RSG) phase plays a crucial role in the evolution of an intermediate-mass star; however, the underlying mechanism remains unknown. We aim to increase the sample of well-characterized RSGs at subsolar metallicity by deriving the physical properties of 127 RSGs in nine nearby southern galaxies. For each RSG, we pr…
JWST/NIRSpec and MIRI observations of an expanding, jet-driven bubble of warm H2 in the radio galaxy 3C 326 N
Petrov, R.; Nesvadba, N. P. H.; Mukherjee, D. +5 more
The physical link between AGN activity and the suppression of star formation in their host galaxies is one of the major open questions of the AGN feedback scenario. The Spitzer space mission revealed a subset of powerful nearby radio galaxies with unusually bright line emission from warm (T ≥ 100 K) molecular hydrogen, while typical star-formation…
MALS discovery of a rare H I 21 cm absorber at z ∼ 1.35: Origin of the absorbing gas in powerful active galactic nuclei
Momjian, E.; Combes, F.; Petitjean, P. +14 more
We report a new, rare detection of H I 21 cm absorption associated with a quasar (only six quasars are known at 1 < z < 2) toward J2339−5523 at zem = 1.3531, discovered through the MeerKAT Absorption Line Survey (MALS). The absorption profile is broad (∼400 km s−1 ), and the peak is redshifted by ∼200 km s−1 …
The VMC survey. L. Type II Cepheids in the Magellanic Clouds: Period-luminosity relations in the near-infrared bands
Ripepi, V.; Molinaro, R.; Marconi, M. +8 more
Context. Type II Cepheids (T2Cs) are the less frequently used counterparts of classical or type I Cepheids (CCs) which provide the primary calibration of the distance ladder for measuring the Hubble constant in the local Universe. In the era of the "Hubble tension", T2C variables together with the RR Lyrae stars and the tip of the red giant branch…
A systematic study of the ultra-fast outflow responses to luminosity variations in active galactic nuclei
Guainazzi, Matteo; Bianchi, Stefano; Kara, Erin +7 more
Context. Ultra-fast outflows (UFOs) have been revealed in a large number of active galactic nuclei (AGN) in the past two decades. Their extreme velocities and high ionization states make them a promising candidate for AGN feedback on the evolution of the host galaxy. However, their exact underlying driving mechanism is not yet fully understood.