2011A&A...525A...6M


C.D.S. - SIMBAD4 rel 1.7 - 2020.07.04CEST19:59:55

2011A&A...525A...6M - Astronomy and Astrophysics, volume 525A, 6-6 (2011/1-1)

The transition from quasar radio-loud to radio-quiet state in the framework of the black hole scalability hypothesis.

MARECKI A. and SWOBODA B.

Abstract (from CDS):

There are several lines of evidence that active galactic nuclei (AGN) can be regarded as scaled-up X-ray binaries (XRB). The timescales of the evolutionary phenomena in these two classes are proportional to the black hole (BH) masses. Consequently, unlike in the case of XRBs, the evolution of AGNs is too slow to be followed directly. What could be done, however, is to assign particular types of active galaxies to different evolutionary stages observable in XRBs. We studied such an assignment for three quasars with clear signatures of a recent transition from the radio-loud to the radio-quiet state. The quasars we investigated have large-scale radio lobes that are clearly asymmetric - one lobe is of Fanaroff-RileyII type, while the other one is a diffuse relic devoid of a hotspot. We suggest that the prime cause of the asymmetry of these radio sources is that the nuclei of their host galaxies currently produce no jets. To prove that, we observed them with milliarcsecond resolution to check if they are similar to those in radio-quiet quasars. The observations carried out with the EVN revealed that the nuclei of the quasars under investigation are not of a core-jet type that is characteristic for radio-loud, lobe-dominated quasars. It follows that the lobes are no longer fuelled and that the apparent asymmetry results from the orientation, which causes a time lag of the order of 106 years between their images: the lobe perceived as a relic is nearer than the lobe with a hotspot and so it is observed in a later stage of the decay. The three AGNs under investigation were radio-loud earlier, but now they have switched to the radio-quiet state. In the framework of the XRB/AGN unification, the above means that they have left the very high state and have moved now to the high/soft state. If this scenario is correct it poses a challenge to the so-called spin paradigm. While a radio-loud AGN must have a spinning BH in its centre, the BH of a radio-quiet AGN does not necessarily have low spin; AGNs with high-spin BHs, like those we deal with here, may become radio-quiet.

Abstract Copyright:

Journal keyword(s): radio continuum: galaxies - galaxies: active - X-rays: binaries

Simbad objects: 9

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Number of rows : 9

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 Mrk 1506 Sy1 04 33 11.0958197353 +05 21 15.617543663   15.72 15.05 10.08   ~ 1840 2
2 7C 084700.80+544855.00 QSO 08 50 39.9669541019 +54 37 53.375537489   19.00 18.68     ~ 26 1
3 QSO J1151+3355 QSO 11 51 39.6797010083 +33 55 41.389082805   18.53 18.29     ~ 24 0
4 3C 273 BLL 12 29 06.6996828061 +02 03 08.598846466   13.05 14.830 14.11   ~ 5316 1
5 2MASS J13533592+2631475 Sy1 13 53 35.9252576560 +26 31 47.507782451   17.15 17.18     ~ 56 1
6 V* V821 Ara HXB 17 02 49.3810714542 -48 47 23.163091737 16.20 16.30 15.5     ~ 1764 0
7 NAME Great Annihilator LXB 17 43 54.83 -29 44 42.6           ~ 638 1
8 NAME Sgr A* X 17 45 40.03599 -29 00 28.1699           ~ 3446 3
9 Granat 1915+105 LXB 19 15 11.54938 +10 56 44.7585           ~ 2281 0

    Equat.    Gal    SGal    Ecl

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2020.07.04-19:59:55

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