2002A&A...396..439L


Query : 2002A&A...396..439L

2002A&A...396..439L - Astronomy and Astrophysics, volume 396, 439-448 (2002/12-3)

Infrared spectroscopy around 4µm of Seyfert 2 galaxies: Obscured broad line regions and coronal lines.

LUTZ D., MAIOLINO R., MOORWOOD A.F.M., NETZER H., WAGNER S.J., STURM E. and GENZEL R.

Abstract (from CDS):

The state of the matter that is obscuring a small circumnuclear region in active galactic nuclei can be probed by observations of its broad emission lines. Infrared lines are particularly useful since they penetrate significant columns of obscuring matter, the properties of which can be constrained by comparing infrared and X-ray obscuration. We report on new 4µm spectroscopy with ISAAC at the ESO VLT of a sample of 12 Seyfert 2 galaxies, probing for broad components to the Brackett α 4.05µm hydrogen recombination line. Broad components are observed in 3 to 4 objects. All objects with a broad component exhibit relatively low X-ray obscuring columns, and our results are consistent with a Galactic ratio of 4µm obscuration to the BLR and X-ray column. In combination with observations of a non-Galactic ratio of visual obscuration of BLRs and X-ray obscuring column in Seyferts, and interpreted in a unified AGN scheme, this result can be reconciled with two interpretations. Either the properties of dust near the AGN are modified towards larger grains, for example through coagulation, in a way that significantly flattens the optical/IR extinction curve, or the ratio of dust obscuration to X-ray column varies for different viewing angles with respect to the axis of symmetry of the putative torus. Our spectra also provide a survey of emission in the [SiIX] 3.94µm coronal line, finding variation by an order of magnitude in its ratio to Brα. The first extragalactic detection of the [CaVII] 4.09µm and [CaV] 4.16µm coronal lines is reported in the spectrum of the Circinus galaxy.

Abstract Copyright:

Journal keyword(s): galaxies: active - galaxies: Seyfert - galaxies: ISM

Simbad objects: 13

goto Full paper

goto View the references in ADS

Number of rows : 13
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 M 77 GiP 02 42 40.7091669408 -00 00 47.859690204 9.70 9.61 8.87 10.1 9.9 ~ 4323 2
2 NGC 2110 Sy2 05 52 11.3768668776 -07 27 22.507465392   14.77 13.51 11.86   ~ 626 1
3 Mrk 1210 Sy2 08 04 05.8608218112 +05 06 49.823376120   14.55 13.7     ~ 281 2
4 NGC 2992 Sy2 09 45 42.045 -14 19 34.90 13.54 13.14 12.18 12.6 12.2 ~ 828 3
5 ESO 434-40 Sy2 09 47 40.1332188528 -30 56 55.960779696   14.10 13.69 12.44   ~ 511 0
6 NGC 3081 Sy2 09 59 29.5437024336 -22 49 34.747341960   13.06 13.55 11.67 12.1 ~ 438 0
7 NGC 4388 Sy2 12 25 46.820 +12 39 43.45 11.91 11.76 11.02     ~ 1260 2
8 NGC 4507 Sy2 12 35 36.6338976888 -39 54 33.710416272   12.95 13.54 11.70 12.4 ~ 464 0
9 NGC 4941 Sy2 13 04 13.1036380320 -05 33 05.752803672   13.18 12.23 10.74   ~ 332 0
10 NGC 4968 Sy2 13 07 05.976 -23 40 37.34   13.78 14.79 12.46   ~ 171 1
11 NAME Circinus Galaxy Sy2 14 13 09.906 -65 20 20.47   10.89 9.84 10.6 10.0 ~ 1093 2
12 NGC 5506 AGN 14 13 14.8761010056 -03 12 27.556909272   15.25 14.38     ~ 1045 0
13 NGC 5643 Sy2 14 32 40.778 -44 10 28.60   11.03 13.60 9.92 10.6 ~ 507 0

To bookmark this query, right click on this link: simbad:objects in 2002A&A...396..439L and select 'bookmark this link' or equivalent in the popup menu


2022.05.25-00:03:37

© Université de Strasbourg/CNRS

    • Contact