Search Publications
Statistical properties of superactive regions during solar cycles 19-23
Zhang, J.; Wang, J. X.; Chen, A. Q. +2 more
Context. Each solar activity cycle is characterized by a small number of superactive regions (SARs) that produce the most violent of space weather events with the greatest disastrous influence on our living environment.
Aims: We aim to re-parameterize the SARs and study the latitudinal and longitudinal distributions of SARs.
Methods: We …
Herschel observations of EXtra-Ordinary Sources (HEXOS): Methanol as a probe of physical conditions in Orion KL
Menten, K. M.; Martin, P. G.; Murphy, J. A. +45 more
We have examined methanol emission from Orion KL withthe Herschel/HIFI instrument, and detected two methanol bands centered at 524 GHz and 1061 GHz. The 524 GHz methanol band (observed in HIFI band 1a) is dominated by the isolated ΔJ = 0, K = -4 → -3, vt = 0 Q branch, and includes 25 E-type and 2 A-type transitions. The 1061 GHz methano…
First detection of hydrogen isocyanide (HNC) in Titan's atmosphere
Lara, L. M.; Hartogh, P.; Lellouch, E. +7 more
We report on the first identification of hydrogen isocyanide (HNC) in Titan's atmosphere, from observations using the HIFI instrument on the Herschel Space Observatory. An emission line from the HNC J = 6 → 5 rotational transition at 543.897 GHz was measured in Titan on June 14 and December 31, 2010. Radiative transfer modeling indicates that the …
Monitoring a high-amplitude δ Scuti star for 152 days: discovery of 12 additional modes and modulation effects in the light curve of CoRoT 101155310
Auvergne, M.; Baudin, F.; Poretti, E. +12 more
Aims: The detection of small-amplitude nonradial modes in high-amplitude δ Sct (HADS) variables has been very elusive until at least five of them were detected in the light curve of V974 Oph obtained from ground-based observations. The combination of radial and nonradial modes has a high asteroseismic potential, thanks to the strong constrain…
Study of the many fluorescent lines and the absorption variability in GX 301-2 with XMM-Newton
Wilms, J.; Ferrigno, C.; Pottschmidt, K. +7 more
We present an in-depth study of the high mass X-ray binary (HMXB) GX 301-2 during its pre-periastron flare using data from the XMM-Newton satellite. The energy spectrum shows a power law continuum absorbed by a large equivalent hydrogen column on the order of 1024 cm-2 and a prominent Fe Kα fluorescent emission line. Besides …
Multi-instrument X-ray monitoring of the January 2009 outburst from the recurrent magnetar candidate 1E 1547.0-5408
Campana, S.; Tiengo, A.; Götz, D. +9 more
Context. With two consecutive outbursts recorded in four months (October 2008 and January 2009), and a possible third outburst in 2007, 1E 1547.0-5408 is one of the most active transient anomalous X-ray pulsars known so far.
Aims: Thanks to extensive X-ray observations, obtained both in the quiescent and active states, 1E 1547.0-5408 represen…
First stars. XV. Third-peak r-process element and actinide abundances in the uranium-rich star CS31082-001
Bonifacio, P.; Spite, M.; Nordström, B. +12 more
Context. A small fraction of extremely metal-poor (EMP) stars exhibit moderate to extreme excesses of heavy neutron-capture elements produced in the r-process. The production site(s) of these elements in the early Galaxy remain(s) unclear, as is the reason for their occasional enhancement in the otherwise regular pattern of abundances of elements …
A high-resolution three-dimensional model of the solar photosphere derived from Hinode observations
Socas-Navarro, H.
A new three-dimensional model of the solar photosphere is presented in this paper and made publicly available to the community. This model has the peculiarity of having been obtained by inverting spectro-polarimetric observations, rather than by using numerical radiation hydrodynamical simulations. The data used here are from the spectro-polarimet…
Multi-wavelength modeling of the spatially resolved debris disk of HD 107146
Ertel, S.; Wolf, S.; Carpenter, J. M. +5 more
Aims: We aim to constrain the location, composition, and dynamical state of planetesimal populations and dust around the young, sun-like (G2 V) star
Methods: We consider coronagraphic observations obtained with the Advanced Camera for Surveys (HST/ACS) onboard the Hubble Space Telescope (HST) in broad V (λ
The continuum intensity as a function of magnetic field. I. Active region and quiet Sun magnetic elements
Solanki, S. K.; Borrero, J. M.; Kobel, P.
Context. Small-scale magnetic fields are major contributors to the solar irradiance variations. Hence, the continuum intensity contrast of magnetic elements in the quiet Sun (QS) network and in active region (AR) plage is an essential quantity that needs to be measured reliably.
Aims: By using Hinode/SP disk center data at a constant, high sp…