1,428 research outputs found
XMM-Newton unveils the type 2 nature of the BLRG 3C 445
We present an observation of XMM-Newton that unambiguously reveals the
``Seyfert 2'' nature of the Broad Line Radio Galaxy 3C 445. For the first time
the soft excess of this source has been resolved. It consists of unobscured
scattered continuum flux and emission lines, likely produced in a warm
photoionized gas near the pole of an obscuring torus. The presence of
circumnuclear (likely stratified) matter is supported by the complex
obscuration of the nuclear region. Seventy percent of the nuclear radiation
(first component) is indeed obscured by a column density ~4*10^{23} cm^{-2},
and 30 % (second component) is filtered by ~7* 10^{22} cm^{-2}. The first
component is nuclear radiation directly observed by transmission through the
thicker regions. The second one is of more uncertain nature. If the observer
has a deep view into the nucleus but near the edge of the torus, it could be
light scattered by the inner wall of the torus and/or by photoionized gas
within the Broad Line Region observed through the thinner rim of the
circumnuclear matter.Comment: MNRAS Letters, in pres
IRAS 13197-1627 has them all: Compton-thin absorption, photo-ionized gas, thermal plasmas, and a broad Fe line
We report results from the XMM-Newton observation of IRAS 13197-1627, a
luminous IR galaxy with a Seyfert 1.8 nucleus. The hard X-ray spectrum is steep
and is absorbed by Compton-thin neutral gas. We detect an Fe emission line at
6.4 keV, consistent with transmission through the absorber. The most striking
result of our spectral analysis is the detection of a dominant X-ray reflection
component and broad Fe line from the inner accretion disc. The
reflection-dominated hard X-ray spectrum is confirmed by the strong Compton
hump seen in a previous BeppoSAX observation and could be the sign that most of
the primary X-rays are radiated from a compact corona (or e.g. base of the jet)
within a few gravitational radii from the black hole. We also detect a
relatively strong absorption line at 6.81 keV which, if interpreted as Fe xxv
resonant absorption intrinsic to the source, implies an outflow with velocity
of about 5000 km/s. In the soft energy band, the high-resolution RGS and the
CCD-resolution data show the presence of both photo-ionized gas and thermal
plasma emission, the latter being most likely associated with a recent
starburst of 15-20 solar masses per year.Comment: accepted for publication in MNRA
ASCA Observations of the Seyfert 2 Galaxy NGC 7582: An Obscured and Scattered View of the Hidden Nucleus
ASCA observations of the Seyfert 2 galaxy NGC 7582 revealed it was highly
variable on the timescale of s in the hard X-ray (2-10 keV)
band, while the soft X-ray (0.5-2 keV) flux remained constant during the
observations.
The spectral analysis suggests that this object is seen through an obscuring
torus with the thickness of N. The
hard X-ray is an absorbed direct continuum from a hidden Seyfert 1 nucleus; the
soft X-ray is dominated by the scattered central continuum from an extended
spatial region. Thus we have an obscured/absorbed and a scattered view of this
source as expected from the unification model for Seyfert galaxies.
More interestingly, the inferred X-ray column was observed to increase by
from 1994 to 1996, suggesting a ``patchy''
torus structure, namely the torus might be composed of many individual clouds.
The observed iron line feature near 6.4 keV with the equivalent width of 170 eV
is also consistent with the picture of the transmission of nuclear X-ray
continuum through a non-uniform torus.Comment: 10 pages, 6 figures. To be appear in PASJ 50 No.5 (1998 Oct.25 issue
ASCA view on High-Redshift Radio-Quiet Quasars
We briefly discuss the latest ASCA results on the X-ray spectral properties
of high-redshift radio-quiet quasars.Comment: 4 pages, 1 figure, to appear in the Proceedings of the Conference
"X-ray Astronomy '999: Stellar Endpoints, AGNs, and the Diffuse X-ray
Background (September 6-10 - 1999
Warm absorber, reflection and Fe K line in the X-ray spectrum of IC 4329A
Results from the X-ray spectral analysis of the ASCA PV phase observation of
the Seyfert 1 galaxy IC 4329A are presented. We find that the 0.4 - 10 keV
spectrum of IC 4329A is best described by the sum of a steep () power-law spectrum passing through a warm absorber plus a strong
reflection component and associated Fe K line, confirming recent results
(Madejski et al. 1995, Mushotsky et al. 1995). Further cold absorption in
excess of the Galactic value and covering the entire source is also required by
the data, consistent with the edge-on galactic disk and previous X-ray
measurements. The effect of the warm absorber at soft X-ray energies is best
parameterized by two absorption edges, one consistent with OVI, OVII or NVII,
the other consistent with OVIII. A description of the soft excess in terms of
blackbody emission, as observed in some other Seyfert 1 galaxies, is ruled out
by the data. A large amount of reflection is detected in both the GIS and SIS
detectors, at similar intensities. We find a strong correlation between the
amount of reflection and the photon index, but argue that the best solution
with the present data is that given by the best statistical fit. The model
dependence of the Fe K line parameters is also discussed. Our best fit gives a
slightly broad ( keV) and redshifted (E keV) Fe K line, with equivalent width 89 33 eV.
The presence of a weak Fe K line with a strong reflection can be reconciled if
one assumes iron underabundances or ionized reflection. We also have modeled
the line with a theoretical line profile produced by an accretion disk. This
yields results in better agreement with the constraints obtained from the
reflection component.Comment: Accepted for publication in The Astrophysical Journal, 10th February
1996 issue; 24 pages and 8 figures + 1 table tared, compressed and uuencoded
(with uufiles
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