ar X iv : a st ro - p h / 99 01 25 3 v 1 1 9 Ja n 19 99 The Detection of Two Distinct High Ionization States in a QSO
نویسنده
چکیده
We have detected two high ionization phases of gas in the z ∼ 2.77 partial Lyman limit system (LLS) towards QSO 1157+3143 . We detect the first phase by CIV and SiIV absorption, and the second phase – which is either warmer or undergoing larger random bulk motions than the first – via OVI absorption. Both phases of gas are present in similar column density ratios in each of the 5 velocity components, making it appear that this LLS is constructed of 5 very similar building blocks. We find that this system displays some of the properties expected of a hierarchical merging event, although published models may have trouble explaining the SiIV absorption we observe. When different ions show similar velocity structure, we commonly assume that they arise in the same gas, and we compare their column densities to derive the ionization and abundances. For this one absorption system the different ions have similar velocity but they do not arise in the same gas. Subject headings: quasars: absorption lines, quasars: individual 1157+3143
منابع مشابه
ar X iv : a st ro - p h / 99 01 10 8 v 1 1 0 Ja n 19 99 Accretion Disk Models
Models of black hole accretion disks are reviewed, with an emphasis on the theory of hard X-ray production. The following models are considered: i) standard, ii) super-critical, iii) two-temperature, and iv) disk+corona. New developments have recently been made in hydrodynamical models of accretion and in phenomenological radiative models fitting the observed X-ray spectra. Attempts to unify th...
متن کاملar X iv : a st ro - p h / 99 01 14 4 v 1 1 2 Ja n 19 99 BeppoSAX observations of bright Seyfert 2 galaxies
We report on BeppoSAX broad band (0.1-100 keV) observations of bright Seyfert 2 galaxies and discuss the results in the framework of the unified theory of AGNs. The data are used to probe N H distribution in type 2 objects and to identify heavily absorbed (10 24 ≤ N H ≤ 10 25 cm −2) sources, which are particularly bright in hard X-rays. They also provide, for the first time, high energy spectra...
متن کاملar X iv : a st ro - p h / 97 01 22 8 v 1 2 9 Ja n 19 97 Large - scale Structures revealed by Wavelet Decomposition 1
متن کامل
ar X iv : a st ro - p h / 96 01 12 9 v 1 2 3 Ja n 19 96 Is Her X - 1 a strange star
The possible identification of Her X-1 with a strange star (Li et al. 1995) is shown to be incorrect.
متن کاملar X iv : a st ro - p h / 99 06 25 1 v 1 1 5 Ju n 19 99 Inflow and outflows in NGC 2992 / 3
We present observational evidences for inflow and outflows in the interacting system Arp 245 (NGC 2992/3).
متن کامل