Search Publications
Revisiting the exomoon candidate signal around Kepler-1625 b
Heller, René; Hippke, Michael; Gizon, Laurent +1 more
Context. Transit photometry of the Jupiter-sized exoplanet candidate Kepler-1625 b has recently been interpreted as showing hints of a moon. This exomoon, the first of its kind, would be as large as Neptune and unlike any moon we know from the solar system.
Aims: We aim to clarify whether the exomoon-like signal is indeed caused by a large ob…
Ejection processes in the young open cluster NGC 2264. A study of the [OI]λ6300Å emission line
Dougados, C.; Bouvier, J.; Alencar, S. H. P. +2 more
Context. Statistical studies of the spectral signatures of jets and winds in young stars are crucial to characterize outflows and understand their impact on disk and stellar evolution. The young, open cluster NGC 2264 contains hundreds of well-characterized classical T Tauri stars (CTTS), being thus an ideal site for these statistical studies. Its…
Expansion patterns and parallaxes for planetary nebulae
Balick, B.; Schönberner, D.; Jacob, R.
Aims: We aim to determine individual distances to a small number of rather round, quite regularly shaped planetary nebulae by combining their angular expansion in the plane of the sky with a spectroscopically measured expansion along the line of sight.
Methods: We combined up to three epochs of Hubble Space Telescope imaging data and det…
Accreting, highly magnetized neutron stars at the Eddington limit: a study of the 2016 outburst of SMC X-3
Vasilopoulos, Georgios; Koliopanos, Filippos
Aims: We study the temporal and spectral characteristics of SMC X-3 during its recent (2016) outburst to probe accretion onto highly magnetized neutron stars (NSs) at the Eddington limit.
Methods: We obtained XMM-Newton observations of SMC X-3 and combined them with long-term observations by Swift. We performed a detailed analysis of the…
Gaia Data Release 2. Calibration and mitigation of electronic offset effects in the data
Smith, M.; Allende Prieto, C.; Boudreault, S. +30 more
Context. The European Space Agency's Gaia satellite was launched into orbit around L2 in December 2013. This ambitious mission has strict requirements on residual systematic errors resulting from instrumental corrections in order to meet a design goal of sub-10 microarcsecond astrometry. During the design and build phase of the science instruments…
Spitzer Planck Herschel Infrared Cluster (SPHerIC) survey: Candidate galaxy clusters at 1.3 < z < 3 selected by high star-formation rate
Altieri, B.; Le Floc'h, E.; Omont, A. +17 more
There is a lack of large samples of spectroscopically confirmed clusters and protoclusters at high redshifts, z > 1.5. Discovering and characterizing distant (proto-)clusters is important for yielding insights into the formation of large-scale structure and on the physical processes responsible for regulating star-formation in galaxies in dense…
The XXL Survey: XXVII. The 3XLSS point source catalogue
Chiappetti, L.; Altieri, B.; Valtchanov, I. +35 more
We present the version of the point source catalogue of the XXL Survey that was used, in part, in the first series of XXL papers. In this paper we release, in our database in Milan and at CDS: (i) the X-ray source catalogue with 26 056 objects in two areas of 25 deg2 with a flux limit (at 3σ) of ~10-15 erg s-1 cm
Multiple cyclotron line-forming regions in GX 301-2
Pottschmidt, K.; Natalucci, L.; Kretschmar, P. +6 more
We present two observations of the high-mass X-ray binary GX 301-2 with NuSTAR, taken at different orbital phases and different luminosities. We find that the continuum is well described by typical phenomenological models, like a very strongly absorbed NPEX model. However, for a statistically acceptable description of the hard X-ray spectrum we re…
Multi-wavelength campaign on NGC 7469. III. Spectral energy distribution and the AGN wind photoionisation modelling, plus detection of diffuse X-rays from the starburst with Chandra HETGS
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +15 more
We investigate the physical structure of the active galactic nucleus (AGN) wind in the Seyfert-1 galaxy NGC 7469 through high-resolution X-ray spectroscopy with Chandra HETGS and photoionisation modelling. Contemporaneous data from Chandra, HST, and Swift are used to model the optical-UV-X-ray continuum and determine the spectral energy distributi…
Testing the accuracy of reflection-based supermassive black hole spin measurements in AGN
Nardini, E.; Kammoun, E. S.; Risaliti, G.
Context. X-ray reflection is a very powerful method to assess the spin of supermassive black holes (SMBHs) in active galactic nuclei (AGN), yet this technique is not universally accepted. Indeed, complex reprocessing (absorption, scattering) of the intrinsic spectra along the line of sight can mimic the relativistic effects on which the spin measu…