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http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/1943| Accurate classification of 29 objects detected in the 39 month Palermo Swift/BAT hard X-ray catalogue ⋆, ⋆ ⋆ | |
| Vahram Chavushyan | |
| Acceso Abierto | |
| Atribución-NoComercial-SinDerivadas | |
| Atomic data X-rays: galaxies X-rays: binaries Novae, cataclysmic variables | |
| Through an optical campaign performed at four telescopes located in the northern and the southern hemispheres, plus archival data from two on-line sky surveys, we obtained optical spectroscopy for 29 counterparts of unclassified or poorly studied hard X-ray emitting objects detected with Swift /Burst Alert Telescope (BAT) and listed in the 39 month Palermo catalogue. All these objects also have observations taken with Swift /X-ray Telescope (XRT) or XMM-European Photon Imaging Camera (EPIC) which not only allow us to pinpoint their optical counterpart, but also study their X-ray spectral properties (column density, power law photon index, and F₂₋₁₀ keV flux). We find that 28 sources in our sample are active galactic nuclei (AGNs); 7 are classified as type 1, while 21 are of type 2; the remaining object is a Galactic cataclysmic variable. Among our type 1 AGNs, we find 5 objects of intermediate Seyfert type (1.2−1.9) and one narrow-line Seyfert 1 galaxy; for 4 out of 7 sources, we are able to estimate the central black hole mass. Three of the type 2 AGNs of our sample display optical features typical of low-ionization nuclear emission-line regions (LINER) and one is a likely Compton thick AGN. All galaxies classified in this work are relatively nearby objects since their redshifts lie in the range 0.008−0.075; the only Galactic object found lies at an estimated distance of 90 pc. We also investigate the optical versus X-ray emission ratio of the galaxies of our sample to test the AGN unified model. For these galaxies, we also compare the X-ray absorption (caused by gas) with the optical reddening (caused by dust): we find that for most of our sources, specifically those of type 1.9−2.0 the former is higher than the latter confirming early results of Maiolino and collaborators; this is possibly due to the properties of dust in the circumnuclear obscuring torus of the AGN. | |
| Astronomy & Astrophysics | |
| 2012 | |
| Artículo | |
| Inglés | |
| Estudiantes Investigadores Público en general | |
| Parisi, P., et al., (2012), Accurate classification of 29 objects detected in the 39 month Palermo Swift/BAT hard X-ray catalogue ⋆, ⋆ ⋆, Astronomy & Astrophysics, Vol. 545(A101):1-14 | |
| ASTRONOMÍA Y ASTROFÍSICA | |
| Versión aceptada | |
| acceptedVersion - Versión aceptada | |
| Aparece en las colecciones: | Artículos de Astrofísica |
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