Search Publications

Estimating [α/Fe] from Gaia low-resolution BP/RP spectra using the ExtraTrees algorithm
DOI: 10.1051/0004-6361/202141589 Bibcode: 2021A&A...656A..93G

Fouesneau, Morgan; Andrae, René; Korn, Andreas J. +2 more

Context. Gaia Data Release 3 will contain more than a billion sources with positions, parallaxes, and proper motions. In addition, for hundreds of millions of stars, it will include low-resolution blue photometer (BP) and red photometer (RP) spectra. Obtained by dispersing light with prisms, these spectra have resolutions that are too low to allow…

2021 Astronomy and Astrophysics
Gaia 12
The IBISCO survey. I. Multiphase discs and winds in the Seyfert galaxy Markarian 509
DOI: 10.1051/0004-6361/202039773 Bibcode: 2021A&A...655A..25Z

Fiore, F.; Piconcelli, E.; Dadina, M. +9 more

We present the analysis of the ALMA CO(2−1) emission line and the underlying 1.2 mm continuum of Mrk 509 with spatial resolution of ∼270 pc. This local Seyfert 1.5 galaxy, optically classified as a spheroid, is known to host an ionised disc, a starburst ring, and ionised gas winds on both nuclear (ultra-fast outflows) and galactic scales. From CO(…

2021 Astronomy and Astrophysics
INTEGRAL eHST 12
Nowhere to hide: Radio-faint AGN in the GOODS-N field. II. Multi-wavelength AGN selection techniques and host galaxy properties
DOI: 10.1051/0004-6361/202038591 Bibcode: 2021A&A...649A..27R

Muxlow, T. W. B.; Thomson, A. P.; Garrett, M. A. +3 more

Context. Obtaining a census of active galactic nuclei (AGN) activity across cosmic time is critical to our understanding of galaxy evolution and formation. Many AGN classification techniques are compromised by dust obscuration. However, very long baseline interferometry (VLBI) can be used to identify high brightness temperature compact radio emiss…

2021 Astronomy and Astrophysics
Herschel eHST 12
Stellar Population Astrophysics (SPA) with the TNG. Stock 2, a little-studied open cluster with an eMSTO
DOI: 10.1051/0004-6361/202141747 Bibcode: 2021A&A...656A.149A

Vallenari, A.; Bragaglia, A.; Spina, L. +14 more

Stock 2 is a little-studied open cluster that shows an extended main-sequence turnoff (eMSTO). In order to investigate this phenomenon and characterise the cluster itself, we performed high-resolution spectroscopy in the framework of the Stellar Population Astrophysics project. We employed the High Accuracy Radial velocity Planet Searcher in the N…

2021 Astronomy and Astrophysics
Gaia 12
The search for extratidal star candidates around Galactic globular clusters NGC 2808, NGC 6266, and NGC 6397 with Gaia DR2 astrometry
DOI: 10.1051/0004-6361/202038720 Bibcode: 2021A&A...645A.116K

Piatti, Andrés E.; Minniti, Dante; Fernández-Trincado, José G. +5 more

Context. Extratidal stars are stellar bodies that end up outside the tidal radius of a cluster as a result of internal processes or external forces acting upon it. The presence and spatial distribution of these stars can give us insights into the past evolution of a cluster inside our Galaxy.
Aims: Previous works suggest that globular cluster…

2021 Astronomy and Astrophysics
Gaia 12
SPECIES. II. Stellar parameters of the EXPRESS giant star sample
DOI: 10.1051/0004-6361/202039357 Bibcode: 2021A&A...647A.157S

Jones, M. I.; Soto, M. G.; Jenkins, J. S.

Context. As part of the search for planets around evolved stars, we can understand planet populations around significantly higher-mass stars than the Sun on the main sequence. This population is difficult to study any other way, such as using radial-velocities to measure planet masses and orbital mechanics, since the stars are too hot and rotate t…

2021 Astronomy and Astrophysics
Gaia 12
Spectral analysis of the low-mass X-ray pulsar 4U 1822-371: Reflection component in a high-inclination system
DOI: 10.1051/0004-6361/202140557 Bibcode: 2021A&A...654A.160A

Sanna, A.; Di Salvo, T.; Burderi, L. +6 more

Context. The X-ray source 4U 1822-371 is an eclipsing low-mass X-ray binary and X-ray pulsar, hosting a NS that shows periodic pulsations in the X-ray band with a period of 0.59 s. The inclination angle of the system is so high (80-85°) that in principle, it should be hard to observe both the direct thermal emission of the central object and the r…

2021 Astronomy and Astrophysics
XMM-Newton 12
Combining white light and UV Lyman-α coronagraphic images to determine the solar wind speed. The quick inversion method
DOI: 10.1051/0004-6361/202141276 Bibcode: 2021A&A...654A..58B

Bemporad, A.; Frassati, F.; Giordano, S. +1 more

Context. The availability of multi-channel coronagraphic images in different wavelength intervals acquired from the space will provide a new view of the solar corona, allowing us to investigate the 2D distribution and time evolution of many plasma physical parameters, such as plasma density, temperature, and outflow speed.
Aims: This work foc…

2021 Astronomy and Astrophysics
SolarOrbiter 12
Discovery of a multiphase O VI and O VII absorber in the circumgalactic/intergalactic transition region
DOI: 10.1051/0004-6361/202038021 Bibcode: 2021A&A...656A.107A

Finoguenov, Alexis; Schaye, Joop; Muzahid, Sowgat +4 more


Aims: The observational constraints on the baryon content of the warm-hot intergalactic medium (WHIM) rely almost entirely on far ultraviolet (FUV) measurements. However, cosmological, hydrodynamical simulations predict strong correlations between the spatial distributions of FUV and X-ray absorbing WHIM. We investigate this prediction by ana…

2021 Astronomy and Astrophysics
XMM-Newton eHST 12
Parsec-scale alignments of radio-optical offsets with jets in AGNs from multifrequency geodetic VLBI, Gaia EDR3, and the MOJAVE program
DOI: 10.1051/0004-6361/202140652 Bibcode: 2021A&A...651A..64L

Liu, N.; Zhu, Z.; Barache, C. +5 more


Aims: We aim to study the relative positions of quasar emission centers at different wavelengths in order to help link the various realizations of the International Celestial Reference System (ICRS), and to unveil systematic uncertainties and individual source behavior at different wavelengths.
Methods: We based our study on four catalog…

2021 Astronomy and Astrophysics
Gaia 12