Query : 2020RAA....20..147X

2020RAA....20..147X - Research in Astron. and astroph., 20, 147-147 (2020/September-0)

X-ray absorption and 9.7 µm silicate feature as a probe of AGN torus structure.

XU J., SUN M.-Y., XUE Y.-Q., LI J.-Y. and HE Z.-C.

Abstract (from CDS):

The dusty torus plays a vital role in unifying active galactic nuclei (AGNs). However, the physical structure of the torus remains largely unclear. Here we present a systematical investigation of the torus mid-infrared (MIR) spectroscopic feature, i.e., the 9.7µm silicate line, of 175 AGNs selected from the Swift/BAT Spectroscopic Survey (BASS). Our sample is constructed to ensure that each of the 175 AGNs has Spizter/IRS MIR, optical, and X-ray spectroscopic coverage. Therefore, we can simultaneously measure the silicate strength, optical emission lines, and X-ray properties (e.g., the column density and the intrinsic X-ray luminosity). We show that, consistent with previous works, the silicate strength is weakly correlated with the hydrogen column density ((NHX), albeit with large scatters. For X-ray unobscured AGNs, the silicate-strength-derived V -band extinction and the broad-H_-inferred one are both small; however, for X-ray obscured AGNs, the former is much larger than the latter. In addition, we find that the optical type 1 AGNs with strong X-ray absorption on average show significant silicate absorption, indicating that their X-ray absorption might not be caused by dust-free gas in the broad-line region. Our results suggest that the distribution and structure of the obscuring dusty torus are likely to be very complex. We test our results against the smooth and clumpy torus models and find evidence in favor of the clumpy torus model.

Abstract Copyright:

Journal keyword(s): galaxies: active - infrared: galaxies - quasars: general

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
1 NGC 262 Sy2 00 48 47.14147900 +31 57 25.0845702 14.04 13.90 13.06 8.53   ~ 713 3
2 Mrk 3 Sy2 06 15 36.2812259376 +71 02 14.837219808 14.21 14.03 12.97     ~ 895 3
3 MCG+04-19-017 Sy2 07 59 53.4597207960 +23 23 24.344262096   14.67 14.02     ~ 59 0
4 Mrk 1210 Sy2 08 04 05.8608218112 +05 06 49.823376120   14.55 13.7     ~ 290 2

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