2003A&A...397..557B


C.D.S. - SIMBAD4 rel 1.7 - 2021.03.03CET10:30:55

2003A&A...397..557B - Astronomy and Astrophysics, volume 397, 557-564 (2003/1-2)

1ES 1927+654: Persistent and rapid X-ray variability in an AGN with low intrinsic neutral X-ray absorption and narrow optical emission lines.

BOLLER T., VOGES W., DENNEFELD M., LEHMANN I., PREDEHL P., BURWITZ V., PERLMAN E., GALLO L., PAPADAKIS I.E. and ANDERSON S.

Abstract (from CDS):

We present X-ray and optical observations of the X-ray bright AGN 1ES 1927+654. The X-ray observations obtained with ROSAT and Chandra reveal persistent, rapid and large scale variations, as well as steep 0.1-2.4keV (Γ=2.6±0.3) and 0.3-7.0keV (Γ=2.7±0.2) spectra. The measured intrinsic neutral X-ray column density is approximately 7x1020cm–2. The X-ray timing properties indicate that the strong variations originate from a region, a few hundred light seconds from the central black hole, typical for type 1 AGN. High quality optical spectroscopy reveals a typical Seyfert 2 spectrum with some host galaxy contamination and no evidence of Fe II multiplets or broad hydrogen Balmer wings. The intrinsic optical extinction derived from the BLR and NLR are AV≥3.7 and AV=1.7, respectively. The X-ray observations give an AV value of less than 0.58, in contrast to the optical extinction values. We discuss several ideas to explain this apparent difference in classification including partial covering, an underluminous BLR or a high dust to gas ratio.

Abstract Copyright:

Journal keyword(s): galaxies: active - galaxies: Seyfert - galaxies: individual: 1ES 1927+654 - X-rays: galaxies

Nomenclature: Fig.9: [BVD2003] N (Nos 1-6).

CDS comments: PDS 654 is misprint for PDS 456

Simbad objects: 5

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Number of rows : 5

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 4U 0708-49 Sy1 07 08 41.4887418009 -49 33 06.308287663   16.02 15.7 12.7   ~ 440 0
2 [VV2006] J121255.2+650635 QSO 12 12 55.1581532574 +65 06 34.849039131   21.60 20.65     ~ 18 0
3 2MASX J13251937-3824524 Sy1 13 25 19.3805503234 -38 24 52.611897329   16.64 13.80 15.33   ~ 358 0
4 QSO B1725-142 QSO 17 28 19.7893541722 -14 15 55.855574749   14.69 14.03 13.7   ~ 249 0
5 2MASX J19271951+6533539 Sy1 19 27 19.5368415554 +65 33 54.331474137     15.4     ~ 37 0

    Equat.    Gal    SGal    Ecl

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2021.03.03-10:30:55

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