XMM-Newton first X-ray detection of the LoBAL quasar PG 1700+518
| Autor: | Lucia Ballo, Piconcelli, E., Vignali, C., Schartel, N. |
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| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | NASA Astrophysics Data System |
| Popis: | We report the first high-energy detection of PG 1700+518, a well-known low-ionization broad absorption line quasar (QSO). Due to previous X-ray non-detection, it was classified as soft X-ray weak QSO. We observed PG 1700+518 with XMM-Newton for about 60 ksec divided in three exposures. The spectrum below 2 keV is very steep, Gamma ~ 2.4-3.8, while at higher energies the extremely flat emission (photon index Gamma ~ 0.15, when modelled with a power law) suggests the presence of strong absorption (NH,pl ~ 2\times10^23 cm-2, Gamma fixed to 1.8), or a reflection-dominated continuum. The broad-band flux is consistent with previous non-detection. Simultaneous EPIC and OM data confirm its X-ray weakness (alpha_ox = -2.2). The level of obscuration derived from the X-ray spectra of PG 1700+518 cannot explain its soft X-ray nuclear weakness unless a column density of NH >~ 2\times10^24 cm-2 is present. Accepted for publication in MNRAS; 7 pages, 5 figures, 2 tables |
| Databáze: | OpenAIRE |
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