RADIO-TO-OPTICAL FLUX DENSITY RADIO LUMINOSITY RADIO MORPHOLOGY

1. RADIO LOUD AGN DETECTED BY INTEGRAL M. Molina, on behalf of the INTEGRAL AGN Team • A number of INTEGRAL/IBIScatalogues have been proposed so far, one of the most recent being the third INTEGRAL/IBISsurvey (Bird et al. 2007), which lists around 150 AGN (identified and candidates). The Ve/Va relationship has been applied to the sources in the catalogue in order to extract a complete sample of AGN selected in the hard (20-40 keV) X-ray band. • This complete sample comprises 33 Type I sources, 3 Narrow Line Seyfert 1s, 30 Type II sources and 7 Blazars/QSOs. Among the 33 Type 1 sources we have identified a number of sources which could be classified as “Radio Loud” objects. However, the definition of “radio loudness” is rather loose, depending on which criteria one relies on. The first selection of the sub-sample of candidate radio loud sources has been made by using two diagrams, plotting the ratio between the 1.4/5 GHz luminosity and the 20-100 keV luminosity versus the 1.4/5 GHz luminosity; this ratio is used here to select a group of candidate radio loud AGN. • Using as a dividing line Log(L1.4/5GHz/L20-100keV) ~ -4 we have identified 10 sources, so to investigate their radio loud nature. 4 are simply classified as Seyfert galaxies (open circles) and the others are already known as broad line radio galaxies. The sources are: QSO B0241+62, B3 0309+411B, 3C 111, MCG+08-11-011, Mrk 6, 3C 390.3, IGR J13109-5552, 4C 74.26, S5 2116+81 and IGR J21247+5058. • RADIO-TO-OPTICAL FLUX DENSITY • RADIO LUMINOSITY • RADIO MORPHOLOGY We decided to use 3 criteria to identify “radio loud” sources: • A source is therefore considered RADIO LOUD if it satisfies the criteria F(5GHz)/F(B)≥10, L(5GHz)≥1032 erg s-1 Hz-1 and has a double lobe radio morphology. This kind of morphology is typical of FR II radio sources, which are generally assumed to be the counterparts of radio loud quasars. Orientation-unification theory also suggests that the Radio Quiet/Radio Loud boundary is set by the least radio luminous FR IIs and by the lowest radio-to-optical ratio for an FR II. In our case, the least luminous FR II is IGR J21247+5058, a well known radio galaxy (see Molina et al. 2007), which has Log(L5GHz) ~31 erg s-1 Hz-1. For this reason, we decided to lower L(5GHz) to this value. • In our sample all but 4 sources (Mrk 6, MCG+08-11-011, QSO B0241+62 and IGR J13109-5552) are classified as BLRG and FR IIs and have two lobes extending from the central nucleus. 3 of the 4 Seyfert galaxies show instead an unresolved compact core, although high resolution radio imaging suggests a possible double-lobe morphology; in the case of IGR J13109-5552 an MPGS-2 image shows an unresolved elongated structure. • Adopting all 3 criteria we consider 5 objects as bona fide radio loud AGN (satisfying all 3 criteria), 3 sources fulfill 2 out of 3 requirements, while Mrk 6 and MCG+08-11-011 satisfy only 1 criterion and have therefore been excluded from the sample. Half of the sample is made of newly discovered radio loud AGN. The peculiar case of IGR J21247+5058 The XMM/INTEGRAL spectrum is well described by a cut-off power law, absorbed by two layers of cold material, with column densities of the order of 1023 and 1022 cm-2 , covering 27% and 83% of the central source respectively. IGR J21247+5058 shows the typical behaviour of other BLRG, showing weak reprocessing features and flatter X/Gamma-ray power law slopes than observed in radio quiet Seyfert 1s. It does not however show the presence of a jet component. • Complex absorption is NOT a typical feature in BLRG: so far, it has been observed in only one object, 3C 445 (Sambruna et al. 2007). • Complex absorption is also at odds with the Seyfert 1 classification of IGR J21247+5058. This can be explained if the “clumpy torus” model is invoked (Elitzur & Shlosman 2006). In this model the torus is not a continous toroidal structure, but is made of clouds with NH~1022-1023 cm-2 distributed around the equatorial plane of the AGN. Because of this clumpiness, the difference between type I and type II objects is not only due to orientation effect but it also depends on how many clouds our line of sight intercepts. Contact: molinam@phys.soton.ac.uk