Search Publications
Local Helioseismology of Sunspots: Current Status and Perspectives
Kosovichev, Alexander G.
Mechanisms of the formation and stability of sunspots are among the longest-standing and intriguing puzzles of solar physics and astrophysics. Sunspots are controlled by subsurface dynamics, hidden from direct observations. Recently, substantial progress in our understanding of the physics of the turbulent magnetized plasma in strong-field regions…
Constraints on cosmic-ray efficiency in the supernova remnant RCW 86 using multi-wavelength observations
Giordano, F.; Lemoine-Goumard, M.; Uchiyama, Y. +4 more
Context. Several young supernova remnants (SNRs) have recently been detected in the high-energy (HE; 0.1 < E < 100 GeV) and very-high-energy (VHE; E > 100 GeV) gamma-ray domains. As exemplified by RX J1713.7-3946, the nature of this emission has been hotly debated, and direct evidence for the efficient acceleration of cosmic-ray protons a…
A noon-to-midnight electric field and nightside dynamics in Saturn's inner magnetosphere, using microsignature observations
Krupp, N.; Dougherty, M. K.; Roussos, E. +5 more
We have created a new, updated catalog of energetic electron microsignature events caused by the moons Tethys and Dione. We used electron data of the MIMI-LEMMS detector that is onboard the Cassini spacecraft, in the energy range 20-300 keV and for the period from July 2004 to January 2011. The present study looks at how the location of a moon's w…
Temporal and Spectral Evolution in X- and γ-Rays of Magnetar 1E 1547.0-5408 since its 2008 October Outburst: The Discovery of a Transient Hard Pulsed Component after its 2009 January Outburst
Kuiper, L.; Hermsen, W.; den Hartog, P. R. +1 more
The magnetar 1E 1547.0-5408 exhibited outbursts in 2008 October and 2009 January. In this paper, we present in great detail the evolution of the temporal and spectral characteristics of the persistent total and pulsed emission of 1E 1547.0-5408 between ~1 and 300 keV starting on 2008 October 3 and ending in 2011 January. We analyzed data collected…
X-Ray Observations of the Young Pulsar J1357—6429 and Its Pulsar Wind Nebula
Pavlov, George G.; Kargaltsev, Oleg; Chang, Chulhoon +1 more
We observed the young pulsar J1357—6429 with the Chandra and XMM-Newton observatories. The pulsar spectrum fits well a combination of an absorbed power-law model (Γ = 1.7 ± 0.6) and a blackbody model (kT = 140+60 - 40 eV, R ~ 2 km at the distance of 2.5 kpc). Strong pulsations with pulsed fraction of 42% ± 5%, apparently asso…
Resolving the Vela C ridge with P-ArTéMiS and Herschel
Hill, T.; Rodriguez, L.; André, Ph. +25 more
We present APEX/P-ArTéMiS 450 µm continuum observations of RCW 36 and the adjacent ridge, a high-mass high-column density filamentary structure at the centre of the Vela C molecular cloud. These observations, at higher resolution than Herschel/SPIRE camera, reveal clear fragmentation of the central star-forming ridge. Combined with PACS far-…
Constraining the formation of inner bars: photometry, kinematics and stellar populations in NGC 357
Corsini, E. M.; Aguerri, J. A. L.; Debattista, Victor P. +2 more
Double-barred galaxies are common in the local Universe, with approximately one-third of barred spirals hosting a smaller, inner bar. Nested bars have been proposed as a mechanism to transport gas to the very central regions of the galaxy, trigger star formation and contribute to the growth of the bulge. To test this idea, we perform for the first…
Plasma penetration of the dayside magnetopause
Lundin, R.; Gunell, H.; Dandouras, I. +6 more
Data from the Cluster spacecraft during their magnetopause crossing on 25 January 2002 are presented. The magnetopause was in a state of slow non-oscillatory motion during the observational period. Coherent structures of magnetosheath plasma, here typified as plasmoids, were seen on closed magnetic field lines on the inside of the magnetopause. Us…
The CoRoT B-type binary HD 50230: a prototypical hybrid pulsator with g-mode period and p-mode frequency spacings⋆
Auvergne, M.; Baudin, F.; Poretti, E. +14 more
Context. B-type stars are promising targets for asteroseismic modelling, since their frequency spectrum is relatively simple.
Aims: We deduce and summarise observational constraints for the hybrid pulsator, HD 50230, earlier reported to have deviations from a uniform period spacing of its gravity modes. The combination of spectra and a high-q…
Rotating Wolf-Rayet stars in a post RSG/LBV phase. An evolutionary channel towards long-duration GRBs?
Harries, T. J.; Vink, J. S.; Gräfener, G. +1 more
Context. Wolf-Rayet (WR) stars with fast rotating cores are thought to be the direct progenitors of long-duration gamma-ray bursts (LGRBs). A well accepted evolutionary channel towards LGRBs is chemically-homogeneous evolution at low metallicities, which completely avoids a red supergiant (RSG), or luminous blue variable (LBV) phase. On the other …