Search Publications
Further ALMA observations and detailed modeling of the Red Rectangle
Sánchez Contreras, C.; Alcolea, J.; Santander-García, M. +3 more
Aims: We aim to study the rotating and expanding gas in the Red Rectangle, which is a well known bipolar nebula surrounding a double stellar system whose primary is a post-asymptotic giant branch (post-AGB) star. We analyze the properties of both components and the relation between them. Rotating disks have been very elusive in post-AGB nebul…
AGN feedback in the nucleus of M 51
Meidt, S. E.; Schinnerer, E.; Leroy, A. K. +10 more
AGN feedback is invoked as one of the most relevant mechanisms that shape the evolution of galaxies. Our goal is to understand the interplay between AGN feedback and the interstellar medium in M 51, a nearby spiral galaxy with a modest AGN and a kpc-scale radio jet expanding through the disc of the galaxy. For this purpose, we combine molecular ga…
Search for 511 keV emission in satellite galaxies of the Milky Way with INTEGRAL/SPI
Vincent, Aaron C.; Diehl, Roland; Siegert, Thomas +3 more
Context. The positron (e+) annihilation γ-ray signal in the Milky Way (MW) shows a puzzling morphology: a very bright bulge and a very low surface-brightness disk. A coherent explanation of the e+ origin, propagation through the Galaxy and subsequent annihilation in the interstellar medium has not yet been found. Tentative ex…
High-velocity extended molecular outflow in the star-formation dominated luminous infrared galaxy ESO 320-G030
Colina, L.; Villar-Martín, M.; Planesas, P. +9 more
We analyze new high spatial resolution (~60 pc) ALMA CO(2-1) observations of the isolated luminous infrared galaxy ESO 320-G030 (d = 48 Mpc) in combination with ancillary Hubble Space Telescope optical and near infrared (IR) imaging, as well as VLT/SINFONI near-IR integral field spectroscopy. We detect a high-velocity (~450 km s-1) spat…
Sulphur molecules in the circumstellar envelopes of M-type AGB stars
Olofsson, H.; Justtanont, K.; Black, J. H. +2 more
Aims: The sulphur compounds SO and SO2 have not been widely studied in the circumstellar envelopes of asymptotic giant branch (AGB) stars. By presenting and modelling a large number of SO and SO2 lines in the low mass-loss rate M-type AGB star R Dor, and modelling the available lines of those molecules in a further four …
Close stellar conjunctions of α Centauri A and B until 2050 . An mK = 7.8 star may enter the Einstein ring of α Cen A in 2028
Kervella, P.; Mignard, F.; Thévenin, F. +1 more
The rapid proper motion of the α Cen pair (≈3.7 arcsec yr-1) and its location close to the galactic plane on a rich stellar background combine constructively to make them excellent candidates for close stellar conjunctions with more distant stars. Adding new differential astrometry to archival data, we have refined the orbital parameter…
Gaia FGK benchmark stars: new candidates at low metallicities
Gilmore, G.; Randich, S.; Soubiran, C. +10 more
Context. We have entered an era of large spectroscopic surveys in which we can measure, through automated pipelines, the atmospheric parameters and chemical abundances for large numbers of stars. Calibrating these survey pipelines using a set of "benchmark stars" in order to evaluate the accuracy and precision of the provided parameters and abunda…
Search for associations containing young stars (SACY). VII. New stellar and substellar candidate members in the young associations
Bayo, A.; Montes, D.; Sterzik, M. F. +5 more
Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5-150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M⊙) owing to…
A HIFI view on circumstellar H2O in M-type AGB stars: radiative transfer, velocity profiles, and H2O line cooling
Olofsson, H.; Justtanont, K.; De Beck, E. +4 more
Aims: We aim to constrain the temperature and velocity structures, and H2O abundances in the winds of a sample of M-type asymptotic giant branch (AGB) stars. We further aim to determine the effect of H2O line cooling on the energy balance in the inner circumstellar envelope.
Methods: We use two radiative-transfer co…
Parallax and masses of α Centauri revisited
Boffin, Henri M. J.; Pourbaix, Dimitri
Context. Despite the thorough work of van Leeuwen, the parallax of α Centauri is still far from being carved in stone. Any derivation of the individual masses is therefore uncertain, if not questionable. And yet, that does not prevent this system from being used for calibration purpose in several studies.
Aims: We aim for more accurate model-…