Search Publications
A whole sky study of quasars known population starting from the LQAC-2 compiled catalogue
Barache, C.; Souchay, J.; Gattano, C.
Context. Thanks to huge surveys, such as the Sloan Digital Sky Survey (SDSS), the last decade has shown a dramatic increase in the number of known quasars. In the second release of the general compiled catalogue Large Quasar Astrometric Catalogue (LQAC), 187 504 objects are recorded.
Aims: From this catalogue, we carry out statistical studies…
The ACS Survey of Globular Clusters. XIII. Photometric Calibration in Comparison with Stetson Standards
Anderson, Jay; Majewski, Steven R.; Sarajedini, Ata +11 more
In this study we compare the photometric data of 34 Milky Way globular clusters, observed within the Advanced Camera for Surveys (ACS) Treasury Program (PI: A. Sarajedini) with the corresponding ground-based data, provided by the Photometric Standard Field Catalogs of Stetson. We focus on the transformation between the Hubble Space Telescope/ACS F…
Automated Processing of LASCO Coronal Images: Spurious Point-Source-Filtering and Missing-Blocks Correction
Llebaria, A.; Lamy, P.; Boclet, B. +1 more
We report on automated procedures for correcting the images of the LASCO coronagraph for i) spurious quasi-point-sources such as the impacts of cosmic rays, stars, and planets, and ii) the absence of signal due to transmission errors or dropouts, which results in blocks of missing information in the images. Correcting for these undesirable artifac…
A mass threshold in the number density of passive galaxies at z ~ 2
Giavalisco, M.; McLure, R. J.; Dunlop, J. S. +17 more
The process that quenched star formation in galaxies at intermediate and high redshifts is still the subject of considerable debate. One way to investigate this puzzling issue is to study the number density of quiescent galaxies at z ≃ 2 and its dependence on mass. Here we present the results of a new study based on very deep Ks-band im…
The radio-loud AGN population at z ≳ 1 in the COSMOS field. I. selection and spectral energy distributions
Chiaberge, Marco; Capetti, Alessandro; Baldi, Ranieri D. +1 more
We select a sample of radio galaxies at high redshifts (z ≳ 1) in the COSMOS field by cross-matching optical and infrared (IR) images with the FIRST radio data. The aim of this study is to explore the high-z radio-loud (RL) active galactic nuclei (AGN) population at much lower luminosities than the classical samples of distant radio sources, which…
X-ray Flares Observed from Six Young Stars Located in the Region of Star Clusters NGC 869 and IC 2602
Pandey, J. C.; Singh, K. P.; Kumar, Brijesh +2 more
We present, for the first time, an analysis of seven intense X-ray flares observed from six stars (LAV 796, LAV 1174, SHM2002 3734, 2MASS 02191082+5707324, V553 Car, V557 Car). These stars are located in the region of young open star clusters NGC 869 and IC 2602. These flares detected in the XMM-Newton data show a rapid rise (10–40 min) and a slow…
Searching for small-scale diffuse emission around SGR 1806-20
Tiengo, A.; Mereghetti, S.; Stella, L. +6 more
Diffuse radio emission was detected around the soft gamma-ray repeater SGR 1806-20 after its 2004 powerful giant flare. We study the possible extended X-ray emission at small scales around SGR 1806-20, in two observations by the High Resolution Camera Spectrometer (HRC-S) on board of the Chandra X-ray Observatory: in 2005, 115 days after the giant…
Analysis of Rosetta/VIRTIS spectra of earth using observations from ENVISAT/AATSR, TERRA/MODIS and ENVISAT/SCIAMACHY, and radiative-transfer simulations
Oliva, F.; Irwin, P. G. J.; Capaccioni, F. +7 more
Rosetta, the Solar System cornerstone mission of ESA's Horizon 2000 programme, consists of an orbiter and a lander, and is due to arrive at the comet 67P/Churyumov-Gerasimenko in May 2014. Following its 2004 launch, Rosetta carried out a series of planetary fly-bys and gravitational assists. On these close fly-bys of the Earth, measurements were t…
High-resolution absorption spectroscopy of the circumgalactic medium of the Milky Way
Richter, P.; Fox, A. J.; Bomans, D. +3 more
In this article we discuss the importance of high-resolution absorption spectroscopy for our understanding of the distribution and physical nature of the gaseous circumgalactic medium (CGM) that surrounds the Milky Way. Observational and theoretical studies indicate a high complexity of the gas kinematics and an extreme multi-phase nature of the C…
Comparison of low-harmonics spectra and maps according to the WMAP and Planck space missions
Verkhodanov, O. V.
We present a comparison of the angular power spectra and maps represented by the WMAP and Planck mission teams. The spectra are compared in the the multi pole range (2 ≤ ℓ ≤ 50). The ℓ =5, 7, 13, 29, 37, 41–46 harmonics have a discrepancy in the angular power spectra. The maps of the microwave background and their phase characteristics are studied…