Search Publications
Asteroseismic analysis of the CoRoT δ Scuti star HD 174936
Auvergne, M.; Amado, P. J.; Baudin, F. +13 more
We present an analysis of the δ-Scuti star HD 174936 (
The XMM-Newton serendipitous survey. VI. The X-ray luminosity function
Silverman, J. D.; Ebrero, J.; Page, M. J. +6 more
Aims: To study the cosmological evolution of active galactic nuclei (AGN) is one of the main goals of X-ray surveys. To accurately determine the intrinsic (before absorption) X-ray luminosity function, it is essential to constrain the evolutionary properties of AGN and therefore the history of the formation of supermassive black holes with cosmic …
Combining weak and strong cluster lensing: applications to simulations and MS 2137
Meneghetti, M.; Bartelmann, M.; Merten, J. +2 more
Aims: While weak lensing cannot resolve cluster cores and strong lensing is almost insensitive to density profiles outside the scale radius, combinations of both effects promise to constrain density profiles of galaxy clusters well, and thus to allow testing of the CDM expectation on dark-matter halo density profiles.
Methods: We develop an al…
The spatial clustering of X-ray selected AGN in the XMM-COSMOS field
Finoguenov, A.; Kneib, J. -P.; Maccagni, D. +70 more
We study the spatial clustering of 538 X-ray selected AGN in the 2 deg2 XMM-COSMOS field that are spectroscopically identified with I_AB<23 and span the redshift range z=0.2-3.0. The median redshift and X-ray luminosity of the sample are z = 0.98 and L0.5-10=6.3× 1043 erg s-1, respectively. A strong c…
A fresh look at the seismic spectrum of HD49933: analysis of 180 days of CoRoT photometry
Auvergne, M.; Baudin, F.; García, R. A. +18 more
Context: Solar-like oscillations have now been observed in several stars, thanks to ground-based spectroscopic observations and space-borne photometry. CoRoT, which has been in orbit since December 2006, has observed the star HD49933 twice. The oscillation spectrum of this star has proven difficult to interpret.
Aims: Thanks to a new timeserie…
Solar-like oscillations with low amplitude in the CoRoT target HD 181906
Auvergne, M.; Baudin, F.; Jiménez-Reyes, S. J. +23 more
Context: The F8 star HD 181906 (effective temperature ∼6300 K) was observed for 156 days by the CoRoT satellite during the first long run in the direction of the galactic centre. Analysis of the data reveals a spectrum of solar-like acoustic oscillations. However, the faintness of the target (mv = 7.65) means the signal-to-noise (S/N) i…
Upward propagating high-frequency Alfvén waves as identified from dynamic wave-like spicules observed by SOT on Hinode
Tu, C. -Y.; Marsch, E.; Tian, H. +3 more
Aims: We identify high-frequency Alfvén waves propagating upward in the solar chromosphere and transition region from observation by Solar Optical Telescope (SOT) onboard Hinode.
Methods: The spicule shape is enhanced through application of a normal radial gradient filter and an un-sharp mask on the images taken by SOT. The displaced position …
Black hole growth and starburst activity at z = 0.6-4 in the Chandra Deep Field South. Host galaxies properties of obscured AGN
Merloni, A.; Fiore, F.; Comastri, A. +8 more
Aims: The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured active galactic nuclei (AGN) detected in the CDFS 1 Ms observation and their host galaxies.
Methods: We limited the analysis…
Comparison of transient horizontal magnetic fields in a plage region and in the quiet Sun
Ishikawa, R.; Tsuneta, S.
Aims: The properties of transient horizontal magnetic fields (THMFs) in both plage and quiet Sun regions are obtained and compared.
Methods: Spectro-polarimetric observations with the Solar Optical Telescope (SOT) on the Hinode satellite were carried out with a cadence of about 30 s for both plage and quiet regions located near the disk center…
Signatures of Alfvén waves in the polar coronal holes as seen by EIS/Hinode
Doyle, J. G.; Banerjee, D.; Pérez-Suárez, D.
Context: We diagnose the properties of the plume and interplume regions in a polar coronal hole and the role of waves in the acceleration of the solar wind.
Aims: We attempt to detect whether Alfvén waves are present in the polar coronal holes through variations in EUV line widths.
Methods: Using spectral observations performed over a pola…