Search Publications
XMM-Newton Ultra Narrow Deep Field survey - II. X-ray spectral analysis of the brightest AGN population
Vignali, C.; Nicastro, F.; Krongold, Y. +6 more
In this work, we present the results of a detailed X-ray spectral analysis of the brightest active galactic nuclei (AGNs) detected in the XMM-Newton 1.75 Ms Ultra Narrow Deep Field. We analysed 23 AGNs that have a luminosity range of $\sim 10^{42} {\!-\!} 10^{46}\, \rm {erg}\, \rm {s}^{-1}$ in the $2 {\!-\!} 10\, \rm {keV}$ energy band, redshifts …
TOI-2379 b and TOI-2384 b: two super-Jupiter mass planets transiting low-mass host stars
Butler, R. Paul; Jordán, Andrés; Brahm, Rafael +31 more
Short-period gas giant planets have been shown to be significantly rarer for host stars less massive than the Sun. We report the discovery of two transiting giant planets - TOI-2379 b and TOI-2384 b - with low-mass (early M) host stars. Both planets were detected using Transiting Exoplanet Survey Satellite photometry and for both the transit signa…
The Gaia ultracool dwarf sample - V: the ultracool dwarf companion catalogue
Smart, R. L.; Pinfield, D. J.; Gagné, Jonathan +4 more
We present the Ultracool Dwarf Companion Catalogue of 278 multiple systems, 32 of which are newly discovered, each with at least one spectroscopically confirmed Ultracool Dwarf, within a 100 pc volume-limited sample. This catalogue is compiled using the Gaia Catalogue of Nearby Stars for stellar primaries and the Gaia Ultracool Dwarf Sample for lo…
On the orbital decay of the gas giant Kepler-1658b
Veras, Dimitri; Makarov, Valeri V.; Barker, Adrian J. +1 more
The gas giant Kepler-1658b has been inferred to be spiralling into its sub-giant F-type host star Kepler-1658a (KOI-4). The measured rate of change of its orbital period is $\stackrel{\bf \centerdot }{\textstyle {P}}_{\rm orb}\, =\, -\, 131^{+20}_{-22}\,\rm {ms\,yr^{ -1}}$, which can be explained by tidal dissipation in the star if its modified ti…
A uniform analysis of debris discs with the Gemini Planet Imager II: constraints on dust density distribution using empirically informed scattering phase functions
Duchêne, G.; Wilner, D. J.; Hom, Justin +40 more
Spatially resolved images of debris discs are necessary to determine disc morphological properties and the scattering phase function (SPF) thatantifies the brightness of scattered light as a function of phase angle. Current high-contrast imaging instruments have successfully resolved several dozens of debris discs around other stars, but few studi…
Non-thermal broadening of coronal lines in a 3D MHD loop model
Peter, H.; Solanki, S. K.; De Moortel, I. +2 more
Observed spectral profiles of emission lines from the corona are found to have widths exceeding the thermal line width. To investigate the physical mechanism, we run a 3D magnetohydrodynamics model of a single, straightened loop in which we partially resolve turbulent motions that form in response to the driving by self-consistently evolving magne…
Survey of extended main-sequence turn-offs in galactic open clusters: stellar rotations from Gaia RVS spectra
Milone, A. P.; Cordoni, G.; Marino, A. F. +6 more
The origin of extended main-sequence turn-offs (eMSTO) in star clusters younger than 2 Gyr still challenges our current understanding of stellar evolution. Exploiting data from Gaia Data Release 3 (DR3), we investigate eMSTOs in a large sample of 32 Galactic open clusters younger than 2.4 Gyr. We first validate Gaia rotational velocities from radi…
Deep JWST/NIRCam imaging of Supernova 1987A
Larsson, J.; Lundqvist, P.; Spyromilio, J. +46 more
JWST/NIRCam obtained high angular resolution (0.05-0.1 arcsec), deep near-infrared 1-5 $\mu$m imaging of Supernova (SN) 1987A taken 35 yr after the explosion. In the NIRCam images, we identify: (1) faint H2 crescents, which are emissions located between the ejecta and the equatorial ring, (2) a bar, which is a substructure of the ejecta…
Probing the magnetic field and dust grain properties of two dark clouds L1495 and L1498 through photopolarimetry
Pandey, J. C.; Medhi, B. J.; Das, H. S. +2 more
We present the R-band polarimetry of two low-latitude Lynd's clouds L1495 and L1498 acquired with AIMPOL at Aryabhatta Research Institute of Observational Sciences, Nainital, India. The estimated polarization across the regions of L1495 and L1498 is typically in the range of ~1-5 per cent and the position angle is typically in the range of ~100°-1…
TOI-2374 b and TOI-3071 b: two metal-rich sub-Saturns well within the Neptunian desert
Butler, R. Paul; Bieryla, Allyson; Fernández Fernández, Jorge +40 more
We report the discovery of two transiting planets detected by the Transiting Exoplanet Survey Satellite (TESS), TOI-2374 b and TOI-3071 b, orbiting a K5V and an F8V star, respectively, with periods of 4.31 and 1.27 d, respectively. We confirm and characterize these two planets with a variety of ground-based and follow-up observations, including ph…