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Magnetic fields in Neutron Stars

Rea, N.; Pons, J. A.; Miralles, J. A. +1 more

Isolated neutron stars show a diversity in timing and spectral properties, which has historically led to a classification in different sub-classes. The magnetic field plays a key role in many aspects of the neutron star phenomenology: it regulates the braking torque responsible for their timing properties and, for magnetars, it provides the energy…

An XMM-Newton view of FeKα in High Mass X-rays Binaries

Eikmann, W.; Oskinova, L. M.; Torrejón, J. M. +4 more

We present a comprehensive analysis of the whole sample of available XMM-Newton observations of High Mass X-ray Binaries (HMXBs) until August, 2013, focusing on the FeKα emission line. This line is a key tool to better understand the physical properties of the material surrounding the X-ray source within a few stellar radii (the circumstellar medi…

X-ray spectral variability of low ionization nuclear emission line regions (LINERs)

González-Martín, O.; Márquez, I.; Masegosa, J. +1 more

Although variability is a general property of AGN, and in LINERs variations in timescales of months/years have been found for some objects, it is not clear how these changes occur. The main purpose of this work is to investigate the X-ray variability in LINERs, including the main driver of such variations. We use the 18 LINERs in the Palomar sampl…

Discordant optical and X-ray classification of AGN

Carrera, F. J.; Wiersema, K.; Mateos, S. +1 more

To provide insight into the apparent mismatch between the optical and X-ray absorption properties observed in 10--30 % of Active Galactic Nuclei (AGN), we have conducted a detailed study of two X-ray unabsorbed AGN with a type-2 optical spectroscopic classification. In addition to high quality X-ray spectroscopic observations, that we used to dete…