2014MNRAS.438..647H


Query : 2014MNRAS.438..647H

2014MNRAS.438..647H - Mon. Not. R. Astron. Soc., 438, 647-656 (2014/February-2)

What obscures low-X-ray-scattering active galactic nuclei ?

HONIG S.F., GANDHI P., ASMUS D., MUSHOTZKY R.F., ANTONUCCI R., UEDA Y. and ICHIKAWA K.

Abstract (from CDS):

X-ray surveys have revealed a new class of active galactic nuclei (AGN) with a very low observed fraction of scattered soft X-rays, fscat <0.5 percent. Based on X-ray modelling, these `X-ray new-type', or low observed X-ray-scattering (hereafter, `low-scattering') sources have been interpreted as deeply buried AGN with a high covering factor of gas. In this paper, we address the questions whether the host galaxies of low-scattering AGN may contribute to the observed X-ray properties, and whether we can find any direct evidence for high covering factors from the infrared (IR) emission. We find that X-ray low-scattering AGN are preferentially hosted by highly inclined galaxies or merger systems as compared to other Seyfert galaxies, increasing the likelihood that the line of sight towards the AGN intersects with high columns of host-galactic gas and dust. Moreover, while a detailed analysis of the IR emission of low-scattering AGN ESO 103-G35 remains inconclusive, we do not find any indication of systematically higher dust covering factors in a sample of low-scattering AGN based on their IR emission. For ESO 103-G35, we constrained the temperature, mass and location of the IR emitting dust which is consistent with expectations for the dusty torus. However, a deep silicate absorption feature probably from much cooler dust suggests an additional screen absorber on larger scales within the host galaxy. Taking these findings together, we propose that the low fscat observed in low-scattering AGN is not necessarily the result of circumnuclear dust but could originate from interference of host-galactic gas with a column density of the order of 1022/cm2 with the line of sight. We discuss implications of this hypothesis for X-ray models, high-ionization emission lines and observed star formation activity in these objects.

Abstract Copyright: © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2013)

Journal keyword(s): galaxies: active - galaxies: individual: ESO103 - G35 - galaxies: nuclei - galaxies: Seyfert - infrared: galaxies - X-rays: galaxies

Simbad objects: 17

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Number of rows : 17
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 NGC 235 Sy1 00 42 52.8103465632 -23 32 27.718834092   14.24   12.63   ~ 168 1
2 NGC 262 Bla 00 48 47.14147900 +31 57 25.0845702 14.04 13.90 13.06 8.53   ~ 778 2
3 2C 94 Sy2 01 08 52.8701830824 +13 20 14.262799812   15.19       ~ 494 2
4 NGC 454 PaG 01 14 22.93 -55 23 55.4   14.26       ~ 56 1
5 MCG-07-04-025 Sy2 01 38 37.1620572432 -40 00 41.151457872   14.28   12.96   ~ 103 2
6 LEDA 1073991 AGN 02 28 13.4780034408 -03 15 02.474411076           ~ 9 0
7 NGC 1142 Sy2 02 55 12.2311509144 -00 11 00.807149472   15.42 14.41     ~ 350 1
8 ESO 5-4 Sy2 06 05 41.721 -86 37 55.02   13.55   11.88 12.2 ~ 174 1
9 IC 2461 Sy2 09 19 58.030 +37 11 27.77   15.1       ~ 151 0
10 Mrk 417 Sy2 10 49 30.9259950912 +22 57 52.375267800   16.0       ~ 107 0
11 MCG+08-21-065 LIN 11 35 43.96335 +49 02 15.4939   16       ~ 34 0
12 NGC 4074 Sy2 12 04 29.6666072616 +20 18 58.654406844   15.43 14.44     ~ 174 0
13 MCG-04-30-007 Sy2 12 38 54.5928340392 -27 18 28.009897704   14.59   12.87   ~ 119 1
14 NGC 4992 Sy2 13 09 05.5929226104 +11 38 02.824910124   14.6       ~ 142 0
15 ESO 103-35 Sy2 18 38 20.3204821536 -65 25 39.141804936   14.75 14.53 13.24   ~ 342 0
16 NGC 7172 Sy2 22 02 01.897 -31 52 11.60   12.72 13.61 11.15 25.10 ~ 572 2
17 NGC 7319 Sy2 22 36 03.602 +33 58 33.18   14.57 13.53 12.65   ~ 325 0

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