Search Publications

Spin period evolution of GX 1+4
DOI: 10.1051/0004-6361/201117893 Bibcode: 2012A&A...537A..66G

Kretschmar, P.; Kuulkers, E.; Larsson, S. +4 more


Aims: We aim both to complement the existing data on the spin history of the peculiar accreting X-ray pulsar GX 1+4 with more past and current data from BeppoSAX, INTEGRAL, and Fermi and to interpret the evolution in the framework of accretion theory.
Methods: We used source light curves obtained from BeppoSAX/WFC and INTEGRAL/ISGRI to d…

2012 Astronomy and Astrophysics
INTEGRAL 50
A Tale of Two Populations: The Contribution of Merger and Secular Processes to the Evolution of Active Galactic Nuclei
DOI: 10.1088/0004-637X/751/1/72 Bibcode: 2012ApJ...751...72D

Ballantyne, D. R.; Draper, A. R.

Due to the co-evolution of supermassive black holes and their host galaxies, understanding the mechanisms that trigger active galactic nuclei (AGNs) is imperative to understanding galaxy evolution and the formation of massive galaxies. It is observationally difficult to determine the trigger of a given AGN due to the difference between the AGN lif…

2012 The Astrophysical Journal
INTEGRAL 50
Optical Spectroscopic Atlas of the MOJAVE/2cm AGN Sample
DOI: 10.48550/arXiv.1107.3416 Bibcode: 2012RMxAA..48....9T

Chavushyan, V.; Rosa-González, D.; Torrealba, J. +3 more

We present an optical spectroscopic atlas for 123 core-dominated radio-loud active galactic nuclei with relativistic jets, drawn from the MOJAVE/2cm sample at 15 GHz. It is the first time that spectroscopic and photometric parameters for a large sample of such type of AGN are presented. The atlas includes spectral parameters for the emission lines…

2012 Revista Mexicana de Astronomia y Astrofisica
eHST 50
Limb darkening laws for two exoplanet host stars derived from 3D stellar model atmospheres. Comparison with 1D models and HST light curve observations
DOI: 10.1051/0004-6361/201117868 Bibcode: 2012A&A...539A.102H

Pont, F.; Asplund, M.; Sing, D. +1 more

We compare limb darkening laws derived from 3D hydrodynamical model atmospheres and 1D hydrostatic MARCS models for the host stars of two well-studied transiting exoplanet systems, the late-type dwarfs HD 209458 and HD 189733. The surface brightness distribution of the stellar disks is calculated for a wide sp…

2012 Astronomy and Astrophysics
eHST 50
Geomorphological significance of Ontario Lacus on Titan: Integrated interpretation of Cassini VIMS, ISS and RADAR data and comparison with the Etosha Pan (Namibia)
DOI: 10.1016/j.icarus.2012.01.013 Bibcode: 2012Icar..218..788C

Le Mouélic, S.; Cornet, T.; Rodriguez, S. +11 more

Ontario Lacus is the largest lake of the whole southern hemisphere of Titan, Saturn's major moon. It has been imaged twice by each of the Cassini imaging systems (Imaging Science Subsystem (ISS) in 2004 and 2005, Visual and Infrared Mapping Spectrometer (VIMS) in 2007 and 2009 and RADAR in 2009 and 2010). We compile a geomorphological map and deri…

2012 Icarus
Cassini 50
Magnetic Energy and Helicity Budgets in the Active-region Solar Corona. II. Nonlinear Force-free Approximation
DOI: 10.1088/0004-637X/759/1/1 Bibcode: 2012ApJ...759....1G

Georgoulis, Manolis K.; Tziotziou, Kostas; Raouafi, Nour-Eddine

Expanding on an earlier work that relied on linear force-free (LFF) magnetic fields, we self-consistently derive the instantaneous free magnetic energy and relative magnetic helicity budgets of an unknown three-dimensional nonlinear force-free (NLFF) magnetic structure extending above a single known lower-boundary magnetic field vector. The propos…

2012 The Astrophysical Journal
Hinode SOHO 50
A Comparison between the Stellar and Dynamical Masses of Six Globular Clusters
DOI: 10.1088/0004-637X/755/2/156 Bibcode: 2012ApJ...755..156S

Bellazzini, M.; Sollima, A.; Lee, J. -W.

We present the results of a comprehensive analysis of the structure and kinematics of six Galactic globular clusters. By comparing the results of the most extensive photometric and kinematical surveys available to date with suitable dynamical models, we determine the stellar and dynamical masses of these stellar systems taking into account the eff…

2012 The Astrophysical Journal
eHST 50
Tracking down the Source Population Responsible for the Unresolved Cosmic 6-8 keV Background
DOI: 10.1088/0004-637X/758/2/129 Bibcode: 2012ApJ...758..129X

Lehmer, B. D.; Alexander, D. M.; Bauer, F. E. +10 more

Using the 4 Ms Chandra Deep Field-South (CDF-S) survey, we have identified a sample of 6845 X-ray-undetected galaxies that dominates the unresolved ≈20%-25% of the 6-8 keV cosmic X-ray background (XRB). This sample was constructed by applying mass and color cuts to sources from a parent catalog based on GOODS-South Hubble Space Telescope z-band im…

2012 The Astrophysical Journal
eHST 50
Spatial Analysis of the Polycyclic Aromatic Hydrocarbon Features Southeast of the Orion Bar
DOI: 10.1088/0004-637X/753/2/168 Bibcode: 2012ApJ...753..168B

Boersma, C.; Allamandola, L. J.; Rubin, R. H.

Polycyclic aromatic hydrocarbon (PAH) and dust emission features between 10 and 37 µm, observed with Spitzer at 11 positions southeast of the Bright Bar (BB) in Orion, are analyzed and connected to atomic and H2 lines reported earlier. Variations at these positions indicate changes in local conditions and materials sampled. The ma…

2012 The Astrophysical Journal
eHST 50
Patterns of accumulation and flow of ice in the mid-latitudes of Mars during the Amazonian
DOI: 10.1016/j.icarus.2012.03.010 Bibcode: 2012Icar..219..723D

Head, James W.; Fassett, Caleb I.; Dickson, James L.

Evidence has accumulated that non-polar portions of Mars have undergone significant periods of glaciation during the Amazonian Period. This evidence includes tropical mountain glacial deposits, lobate debris aprons, lineated valley fill, concentric crater fill, pedestal craters, and related landforms, some of which suggest that ice thicknesses exc…

2012 Icarus
MEx 50