Search Publications
Missions
Journals
Publication Years
The State-of-the-art HST Astro-photometric Analysis of the Core of ω Centauri. III. The Main Sequence's Multiple Populations Galore
Anderson, J.; Milone, A. P.; Marino, A. F. +5 more
We take advantage of the exquisite quality of the Hubble Space Telescope 26-filter astro-photometric catalog of the core of ω Cen presented in the first paper of this series and the empirical differential-reddening correction presented in the second paper in order to distill the main sequence into its constituent populations. To this end, we restr…
On-Disc Observations of Flux Rope Formation Prior to Its Eruption
Palmerio, E.; van Driel-Gesztelyi, L.; Kilpua, E. K. J. +6 more
Coronal mass ejections (CMEs) are one of the primary manifestations of solar activity and can drive severe space weather effects. Therefore, it is vital to work towards being able to predict their occurrence. However, many aspects of CME formation and eruption remain unclear, including whether magnetic flux ropes are present before the onset of er…
Population synthesis to constrain Galactic and stellar physics. I. Determining age and mass of thin-disc red-giant stars
Reylé, C.; Robin, A. C.; Lagarde, N. +1 more
Context. The cornerstone mission of the European Space Agency, Gaia, together with forthcoming complementary surveys (CoRoT, Kepler, K2, APOGEE, and Gaia-ESO), will revolutionize our understanding of the formation and history of our Galaxy, providing accurate stellar masses, radii, ages, distances, as well as chemical properties for a very large s…
Variable H13CO+ Emission in the IM Lup Disk: X-Ray Driven Time-dependent Chemistry?
Cleeves, L. Ilsedore; Bergin, Edwin A.; Öberg, Karin I. +3 more
We report the first detection of a substantial brightening event in an isotopologue of a key molecular ion, HCO+, within a protoplanetary disk of a T Tauri star. The H13CO+ J=3-2 rotational transition was observed three times toward IM Lup between 2014 July and 2015 May with the Atacama Large Millimeter/submillimet…
Kinematics of OB-associations in Gaia epoch
Dambis, A. K.; Mel'nik, A. M.
We use stellar proper motions from the Tycho-Gaia Astrometric Solution (TGAS) catalogue to study the kinematics of OB-associations. The TGAS proper motions of OB-associations generally agree well with the Hipparcos proper motions. The parameters of the Galactic rotation curve obtained with TGAS and Hipparcos proper motions agree within the errors.…
The search for multiple populations in Magellanic Cloud clusters - I. Two stellar populations in the Small Magellanic Cloud globular cluster NGC 121
Dalessandro, E.; Salaris, M.; Larsen, S. +14 more
We started a photometric survey using the WFC3/UVIS instrument onboard the Hubble Space Telescope to search for multiple populations within Magellanic Cloud star clusters at various ages. In this paper, we introduce this survey. As first results of this programme, we also present multiband photometric observations of NGC 121 in different filters t…
On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period-Luminosity-Metallicity Relations
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +14 more
We present new theoretical period-luminosity-metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances (Z = 0.0001-0.0198). In deriving the light curves, we tested two sets of atmospheric…
BICEP2 / Keck Array IX: New bounds on anisotropies of CMB polarization rotation and implications for axionlike particles and primordial magnetic fields
Ade, P. A. R.; Bock, J. J.; Crill, B. P. +64 more
We present the strongest constraints to date on anisotropies of cosmic microwave background (CMB) polarization rotation derived from 150 GHz data taken by the BICEP2 & Keck Array CMB experiments up to and including the 2014 observing season (BK14). The definition of the polarization angle in BK14 maps has gone through self-calibration in which…
A centrally heated dark halo for our Galaxy
Binney, James; Cole, D. R.
We construct a new family of models of our Galaxy in which dark matter and disc stars are both represented by distribution functions that are analytic functions of the action integrals of motion. The potential that is self-consistently generated by the dark matter, stars, and gas is determined, and parameters in the distribution functions are adju…
The black hole binary V404 Cygni: a highly accreting obscured AGN analogue
Motta, S. E.; Sánchez-Fernández, C.; Kuulkers, E. +2 more
Typical black hole binaries in outburst show spectral states and transitions, characterized by a clear connection between the inflow on to the black hole and outflows from its vicinity. The transient stellar mass black hole binary V404 Cyg apparently does not fit in this picture. Its outbursts are characterized by intense flares and intermittent p…