ASTRONOMY & ASTROPHYSICS, Volume 546, id.A47, 14 pp.
We observed a B0IVe star, HD 51452, with the high-precision, high-cadence photometric CoRoT satellite and high-resolution, ground-based HARPS and SOPHIE spectrographs to study its pulsations in great detail. We also used the lower resolution spectra available in the BeSS database. Thanks to CoRoT data, we have detected a new kind of pulsations in HD 51452, which are stochastically excited gravito-inertial modes, probably due to its very rapid rotation. These modes are probably also present in other rapidly rotating hot Be stars.
ASTRONOMY & ASTROPHYSICS, Volume 542, id.A34, 11 pp.
BAO are imprinted in the density field by acoustic waves travelling in the plasma of the early universe. Their fixed scale can be used as a standard ruler to study the geometry of the universe. The BAO have been previously detected using correlation functions and power spectra of the galaxy distribution. We present a new method to detect the real-space structures associated with BAO. These baryon acoustic structures are spherical shells of relatively small density contrast, surrounding high density central regions.
ASTRONOMY & ASTROPHYSICS, Volume 542, id.A36, 19 pp.
We study the relations between the multimodality of galaxy clusters drawn from the SDSS DR8 and the environment where they reside. As cluster environment we consider the global luminosity density field, supercluster membership, and supercluster.
ASTRONOMY & ASTROPHYSICS, Volume 542, id.A20, 17 pp.
Our goal is to characterize the ability of the Advanced Large, Homogeneous Area Medium-Band Redshift Astronomical (ALHAMBRA) survey in assigning accurate photo-z's to broad-line AGN (BLAGN) and quasi-stellar objects (QSOs) based on their ALHAMBRA very-low-resolution optical-near-infrared (NIR) spectroscopy. This will serve as a benchmark for any future compilation of ALHAMBRA selected QSOs and the basis for the statistical analysis required to derive luminosity functions up to z ~ 5.
ASTRONOMY & ASTROPHYSICS, Volume 540, id.A123, 18 pp.
We search for the presence of substructure, a non-Gaussian, asymmetrical velocity distribution of galaxies, and large peculiar velocities of the main galaxies in clusters with at least 50 member galaxies, drawn from the SDSS DR8. We employ a number of 3D, 2D, and 1D tests to analyse the distribution of galaxies in clusters: 3D normal mixture modelling, the Dressler-Shectman test, the Anderson-Darling and Shapiro-Wilk tests, as well as the Anscombe-Glynn and the D'Agostino tests. We find the peculiar velocities of the main galaxies, and use principal component analysis to characterise our results.
ASTRONOMY & ASTROPHYSICS, Volume 535, id.A36, 12 pp.
We use data about superclusters drawn from the SDSS DR7 to analyse possible selection effects in the supercluster catalogue, to study the physical and morphological properties of superclusters, to find their possible subsets, and to determine scaling relations for our superclusters. We apply principal component analysis and Spearman's correlation test to study the properties of superclusters. We have found that the parameters of superclusters do not correlate with their distance.
ASTRONOMY & ASTROPHYSICS, Volume 533, id.A23, 9 pp.
Swift J1626.6-5156 is an X-ray pulsar that was discovered in December 2005 during an X-ray outburst. Although the X-ray data suggest that the system is a high-mass X-ray binary, very little information exists on the nature of the optical counterpart. We investigate the emission properties of the optical counterpart in the optical and near-IR bands and the long-term X-ray variability of the system to determine unambiguously the nature of this X-ray pulsar.
ASTRONOMY & ASTROPHYSICS, Volume 532, id.A5, 20 pp.
We study the morphology of a set of superclusters drawn from the SDSS DR7. We calculate the luminosity density field to determine superclusters from a flux-limited sample of galaxies from SDSS DR7 and select superclusters with 300 and more galaxies for our study. We characterise the morphology of superclusters using the fourth Minkowski functional V3, the morphological and the shape parameter We investigate the supercluster sample using multidimensional normal mixture modelling. We use Abell clusters to identify our superclusters with known superclusters and to study the large-scale distribution of superclusters.
ASTRONOMY AND ASTROPHYSICS, Volume 522, id.A92, 19 pp.
The measurement of redshifts for objects on the verge of instrumental observability is difficult and prone to error, as is the case for GRB afterglows. We have developed a new method that is close in philosophy to the photometric redshift technique, which can be applied to spectral data with a very low signal-to-noise ratio. We intend to measure redshifts, while minimising the dangers posed by the usual extraction techniques. GRB afterglows can be described well by a pure power law, over which the separate effects of absorption and reddening in the GRB host, the intergalactic medium, and our own Galaxy are superimposed. We model all these effects over a series of template afterglow spectra to produce a set of clean spectra that reproduce what would reach our telescope.
ASTRONOMY AND ASTROPHYSICS, Volume 522, id.A92, 19 pp.
Aims: We present the results of the study of the substructure and galaxy content of ten rich clusters of galaxies in three different superclusters of the Sloan great wall, the richest nearby system of galaxies (hereafter SGW).