Search Publications
Calibration of Seismic Signatures of Active Regions on the Far Side of the Sun
Hill, F.; Lindsey, C.; González Hernández, I.
Synoptic maps of the far hemisphere of the Sun calculated from seismic holography have proven to be very reliable in localizing large active regions before they rotate onto the visible hemisphere. We show here the first results toward a calibration of the far-side signatures of active regions in terms of active region size and magnetic field stren…
Deconstructing dwarf galaxies: a Suprime-Cam survey of Andromeda II
McConnachie, Alan W.; Arimoto, Nobuo; Irwin, Mike
We present deep, subhorizontal-branch, multicolour photometry of the Andromeda II dwarf spheroidal (And II dSph) taken with the Subaru Suprime-Cam wide-field camera. We identify a red clump population in this galaxy, the first time this feature has been detected in an M31 dSph, which are normally characterized as having no significant intermediate…
Identification of Ne VIII lines in H-deficient (pre-) white dwarfs: a new tool to constrain the temperature of the hottest stars
Rauch, T.; Werner, K.; Kruk, J. W.
For the first time, we have identified Ne VIII absorption lines in far-UV spectra of the hottest known (T_eff ⪆ 150 000 K) hydrogen-deficient (pre-) white dwarfs of spectral type PG1159. They are of photospheric origin and can be matched by synthetic non-LTE line profiles. We also show that a number of UV and optical emission lines in these stars …
South Pole of Mars: Nature and composition of the icy terrains from Mars Express OMEGA observations
Bibring, J. -P.; Gondet, B.; Langevin, Y. +6 more
Monitoring the exchange of CO 2, H 2O and dust between the atmosphere, regolith, seasonal deposits and the permanent polar caps of Mars is required to study the climate of the planet and its evolution. The imaging spectrometer Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA) of Mars Express contribute…
Phase-resolved Spectroscopy of the Vela Pulsar with XMM-Newton
Caraveo, P. A.; De Luca, A.; Manzali, A.
The ~104 yr old Vela Pulsar represents the bridge between the young Crab-like and the middle-aged rotation-powered pulsars. Its multiwavelength behavior is due to the superposition of different spectral components. We take advantage of the unprecedented harvest of photons collected by XMM-Newton to assess the Vela Pulsar spectral shape …
Saturn's dynamic D ring
Nicholson, Philip D.; Porco, Carolyn C.; Hedman, Matthew M. +8 more
The Cassini spacecraft has provided the first clear images of the D ring since the Voyager missions. These observations show that the structure of the D ring has undergone significant changes over the last 25 years. The brightest of the three ringlets seen in the Voyager images (named D72), has transformed from a narrow, <40-km wide ringlet to …
Ceres lightcurve analysis—Period determination
Esquerdo, Gilbert A.; Sykes, Mark V.; Chamberlain, Matthew A.
The sidereal period of Ceres is refined from 9.075 h to 9.074170±0.000002, making use of recent and historical lightcurves spanning almost 50 years. An observed increase in the amplitude of the lightcurve with solar phase angle is consistent with bright, discrete albedo features contributing a greater fraction of light as the defect of illuminatio…
Quiet-Sun Magnetic Fields from Space-borne Observations: Simulating Hinode's Case
Bellot Rubio, L. R.; del Toro Iniesta, J. C.; Orozco Suárez, D.
We examine whether it is possible to derive the field strength distribution of quiet-Sun internetwork regions from very high spatial resolution polarimetric observations in the visible. In particular, we consider the case of the spectropolarimeter attached to the Solar Optical Telescope aboard Hinode. Radiative magnetoconvection simulations are us…
Evidence for relativistic features in the X-ray spectrum of Mrk 335
Nandra, K.; Cappi, M.; Longinotti, A. L. +1 more
We present an analysis of hard X-ray features in the spectrum of the bright Sy 1 galaxy Mrk 335 observed by the XMM-Newton satellite. Our analysis confirms the presence of a broad, ionized Fe Kα emission line in the spectrum, first found by Gondoin et al. The broad line can be modelled successfully by relativistic accretion disc reflection models.…
A deficit of faint red galaxies in the possible large-scale structures around the RDCS J1252.9-2927 cluster at z = 1.24
Kodama, Tadayuki; Rosati, Piero; Kajisawa, Masaru +5 more
We report a discovery of possible large-scale structures around the RDCS J1252.9-2927 cluster at z = 1.24 based on photometric redshifts. We carried out multiband wide-field imaging with Suprime-Cam on the Subaru Telescope and WFCAM on the United Kingdom Infrared Telescope (UKIRT). Our data cover an approximately 35 × 30-arcmin2 field i…