Search Publications
Observations of solar small-scale magnetic flux-sheet emergence
Bello González, N.; Borrero, J. M.; Fischer, C. E. +1 more
Aims: Two types of flux emergence were recently discovered in numerical simulations: magnetic loops and magnetic sheet emergence. While magnetic loop emergence has been documented well in recent years using high-resolution full Stokes data from ground-based telescopes as well as satellites, magnetic sheet emergence is still an understudied pr…
LISA Pathfinder Performance Confirmed in an Open-Loop Configuration: Results from the Free-Fall Actuation Mode
Mendes, L.; Russano, G.; Nofrarias, M. +75 more
We report on the results of the LISA Pathfinder (LPF) free-fall mode experiment, in which the control force needed to compensate the quasistatic differential force acting on two test masses is applied intermittently as a series of "impulse" forces lasting a few seconds and separated by roughly 350 s periods of true free fall. This represents an al…
Supergiant Fast X-ray Transients uncovered by the EXTraS project: flares reveal the development of magnetospheric instability in accreting neutron stars
Esposito, Paolo; Belfiore, Andrea; Salvaterra, Ruben +5 more
The low luminosity, X-ray flaring activity, of the sub-class of high-mass X-ray binaries called Supergiant Fast X-ray Transients, has been investigated using XMM-Newton public observations, taking advantage of the products made publicly available by the EXTraS project. One of the goals of EXTraS was to extract from the XMM-Newton public archive in…
The CEMP star SDSS J0222-0313: the first evidence of proton ingestion in very low-metallicity AGB stars?
Salvadori, S.; Bonifacio, P.; Caffau, E. +9 more
Context. Carbon-enhanced metal-poor (CEMP) stars are common objects in the metal-poor regime. The lower the metallicity we look at, the larger the fraction of CEMP stars with respect to metal-poor stars with no enhancement in carbon. The chemical pattern of CEMP stars is diversified, strongly suggesting a different origin of the C enhancement in t…
Searching for g modes. II. Unconfirmed g-mode detection in the power spectrum of the time series of round-trip travel time
Corbard, T.; Appourchaux, T.
Context. The recent claims of g-mode detection have restarted the search for these potentially extremely important modes. The claimed detection of g modes was obtained from the analysis of the power spectrum of the time series of round-trip travel time of p modes.
Aims: The goal of this paper is to reproduce these results on which the claims …
The signal of decaying dark matter with hydrodynamical simulations
Lovell, Mark R.; Crain, Robert A.; Schaye, Joop +11 more
Dark matter particles may decay, emitting photons. Drawing on the EAGLE family of hydrodynamical simulations of galaxy formation - including the APOSTLE and C-EAGLE simulations - we assess the systematic uncertainties and scatter on the decay flux from different galaxy classes, from Milky Way satellites to galaxy clusters, and compare our results …
Peering at the outflow mechanisms in the transitional pulsar PSR J1023+0038: simultaneous VLT, XMM-Newton, and Swift high-time resolution observations
D'Avanzo, P.; Campana, S.; Casella, P. +6 more
We report on a simultaneous near-infrared, optical, and X-ray campaign performed in 2017 with the XMM-Newton and Swift satellites and the HAWK-I instrument mounted on the Very Large Telescope (VLT) on the transitional millisecond pulsar PSR J1023+0038. Near-infrared observations were performed in fast-photometric mode (0.5 s exposure time) in orde…
Broad-band X-ray analysis of local mid-infrared-selected Compton-thick AGN candidates
Pozzi, F.; Vignali, C.; Gruppioni, C. +2 more
The estimate of the number and space density of obscured active galactic nuclei (AGNs) over cosmic time still represents an open issue. While the obscured AGN population is a key ingredient of the X-ray background synthesis models and is needed to reproduce its shape, a complete census of obscured AGN is still missing. Here we test the selection o…
The Dynamics of Saturn's Main Aurorae
Badman, S. V.; Ray, L. C.; Cowley, S. W. H. +9 more
Saturn's main aurorae are thought to be generated by plasma flow shears associated with a gradient in angular plasma velocity in the outer magnetosphere. Dungey cycle convection across the polar cap, in combination with rotational flow, may maximize (minimize) this flow shear at dawn (dusk) under strong solar wind driving. Using imagery from Cassi…
Unusually high magnetic fields in the coma of 67P/Churyumov-Gerasimenko during its high-activity phase
Tsurutani, B. T.; Behar, E.; Nilsson, H. +10 more
Aims: On July 3, 2015, an unprecedented increase in the magnetic field magnitude was measured by the Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko (67P). This increase was accompanied by large variations in magnetic field and ion and electron density and energy. To our knowledge, this unusual event marks the highest magnetic fie…