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Notes for object NGC 3486

11 note(s) found in NED.


1. 2008MNRAS.390.1241B
Re:NGC 3486
4.3 NGC 3486 The XMM-Newton spectrum of NGC 3486 is well fitted by a power-law
absorbed by the Galactic column only and so appears to be another unabsorbed
Seyfert 2 galaxy. However, an excess at hard energies points to a different
scenario. The spectrum is also well fitted by the addition of a Compton
reflection model (pexmon, Nandra et al. 2007) with an underlying thermal
component (raymond), so this could in fact be a Compton thick Seyfert 2 which
looks unabsorbed. We also attempt to add a strongly absorbed transmission
component to the model, which also improves the fit from a simple power law.
However, the column density of this component is poorly constrained, so we fix
this to an arbitrary log(N_H_)=24.5. Estimates of the intrinsic L_HX_
from the reflection component predict a L_Bol_ which agrees well with L_Bol_
estimated from L_[O III]_, suggesting that NGC 3486 is underluminous in X-rays
due to Compton thick obscuration. Finally, there is no evidence for variability
of the X-ray flux in the XMM- Newton observation.

2. 2008MNRAS.390.1241B
Re:NGC 3486
5.3.3 NGC 3486 Fitting the hard excess in the X-ray spectrum of NGC 3486 with a
reflection model yields an improved fit to this data, but the significance is
too low to conclude that the source is Compton thick, as a reflection spectrum
would imply. However, the XMM-Newton spectrum here, is in all ways similar to
the Chandra spectrum of NGC 4501, which we showed to originate from a hard
nucleus which is very likely Compton thick. As NGC 3486 is severely
underluminous in hard X-rays when compared to optical and mid-infrared
luminosities, this conclusion seems likely for NGC 3486 too. Again we need to
observe this Seyfert 2 above 10 keV to confirm our hypothesis, or with the high
angular resolution capabilities of Chandra.

3. 2007MNRAS.377.1696M
Re:NGC 3486
NGC 3486. In this borderline Seyfert/LINER nucleus, no radio cores at 6 and 20
cm were detected at a VLA resolution of 1 arcsec by Ho & Ulvestad (2001), to a
3{sigma} limit of 0.12 mJy beam^-1^.
In the UV monitoring by M05, this source displayed neither short-term changes
between the two, closely spaced (by 1 month), epochs in which it was observed,
nor long-term variations when comparing the 2500-A flux to a 2300-A measurement
in 1993 with the HST/FOC by Maoz et al. (1996). The 2500- and 3300-A flux levels
are 10.8 * 10^-17^ and 18.2 * 10^-17^ erg cm^-2^ s^-1^ A^-1^, respectively.
Thus, there is no variability-based lower limit on the AGN flux in this object.
Ho et al. (2001) used Chandra to set an upper limit of 0.5 * 10^-14^ erg
cm^-2^ s^-1^ on the 2-10 keV nuclear flux.
Given the X-ray and radio non-detections and the UV non-variability, M05
discussed the possibility that this is another non-AGN LINER with UV emission
dominated by stars, such as NGC 4569 and 5055, which I have excluded from the
present sample for this reason. M05 noted, however, that M81 and M87, which are
clearly AGNs with variable UV flux, were also near their 'historical' UV levels
in the M05 campaign, and were constant in the two closely spaced epochs (for
M87) or in four out of five epochs (for M81). Thus, detection of short-term
variability in NGC 3486 might have been possible with better temporal sampling.
I will therefore keep NGC 3486 in the sample, allowing for the possibility that
its UV flux is AGN dominated.

4. 2007AJ....134..648M
Re:NGC 3486
NGC 3486 (Figs. 7.49, 9.49, 20.49): This is a borderline object between a
Seyfert and a LINER galaxy, classified as Sy2 by Ho et al. (1997). It has a
bright nucleus and extended emission with dust patches spiraling inward.

5. 2003ApJS..146..353M
Re:NGC 3486
NGC 3486 (LW)
While this galaxy appears to have a weak grand-design spiral at larger
radii, in the central hundred parsecs these dust lanes fragment into a
multiarm spiral. This galaxy was therefore classified as a loosely
wound spiral, rather than a grand-design type.

6. 2002A&A...392..817F
Re:NGC 3486
3.3 NGC 3486
One ULX has been detected at 23'' from the optical centre. The
statistics are sufficient to perform a spectral fitting. The best-fit
model is obtained with a simple power law model with a photon index of
2.2 +/- 0.5({chi^2^= 7.7, {nu} = 14). The 0.5-10 keV flux is
8.3x10^-14^ erg cm^-2^ s^-1^, which corresponds to a luminosity of
5x10^38^ erg s^-1^. The fits are worse, but still acceptable, with the BB
({chi^2^=13.3, {nu} = 14) and MCD ({chi^2^=11.9, {nu} = 14 , ) models.
The former gives a temperature of kT = 0.26 +/- 0.05 keV, while the latter
gives a temperature of the inner disk of kT = 0.4 +/- 0.2 keV.
After the analysis of 41.3 ks of ASCA/SIS0 data, Pappa et al. (2001)
found, for this galaxy, an observed flux of 5x10^-14^ erg cm^-2^ s^-1^
(in the energy band 0.8-10 keV), using a power law with {GAMMA} = 1.9
absorbed by an additional column density of 3.2 x 10^21^ cm^-2^. They
suggested that NGC 3486 may be an obscured Seyfert 2 galaxy. However,
from XMM-Newton data, in a circle of 10'' centered in the optical centre
of NGC 3486, the count rate is (2.1 +/- 0.7) x 10^-3^ s^-1^, which
corresponds to a flux of (9 +/- 3) x 10^-15^ erg cm^-2^ s^-1^ (given the
conversion factor used in this paper). The luminosity is
(6 +/- 2) x 10^37^ erg s^-1^ in the 0.5-10 keV energy band. These data
are compatible with those of Chandra (Ho et al. 2001) and the upper limit
of ROSAT/HRI (6.1 x 10^-14^ erg cm^-2^ s^-1^ in the 0.1-2.4 keV band;
Halderson et al. 2001).
Since the ASCA flux was calculated by extracting photons in wider regions
(1.5'), because of the low angular resolution, this suggest the source
observed by ASCA was not the nucleus, but the ULX, at only 23'' (~825 pc)
from the optical centre of NGC 3486.

7. 2001ApJS..133...77H
Re:NGC 3486
NGC 3486 (S2). - Not detected. Hummel et al. (1987) obtained a less
stringent upper limit of S_20_ < 0.5 mJy ({DELTA}{theta} = 1.3").

8. 1994CAG1..B...0000S
Re:NGC 3486
Sbc(r)I.2
PH-8022-S
Feb 3/4, 1981
103aO
12 min
Many of the spiral fragments in NGC 3486
can be traced for only short distances before
their surface brightness becomes so low that the
outer features are lost. In these outer regions, the
HII region content that defines the path of the
spiral substantially decreases.
The overall spiral pattern is very regular.
The pattern starts at the rim of a
high-surface-brightness inner ring. The nucleus is
exceedingly bright, appearing nearly starlike by
visual inspection at a large telescope.
The several largest HII regions resolve at
the 4" level for the core plus halo diameter. The
redshift is low, v_o = 636 km/s.

9. 1976RC2...C...0000d
Re:NGC 3486
Description: and Photograph:
IAU Symp. No.38, 435, 1970.
HII Regions:
"Atlas and Catalogue", Univ. Washington, Seattle, 1966
Ap. J., 155, 417, 1969.
Ap. J., 194, 559, 1974.
Distance Modulus:
Ap. J., 194, 559, 1974.

10. 1973UGC...C...0000N
Re:UGC 06079
SAB(r)c (de Vaucouleurs), Sc- (Holmberg)

11. 1964RC1...C...0000d
Re:NGC 3486
Bright diffuse nucleus in weak bar: 0.55 arcmin x 0.1 arcmin. Partially
resolved knotty (r): 0.7 arcmin x 0.5 arcmin. Many partially resolved,
filamentary, branching arms. Similar to NGC 6744.
HA 88, 2 dimensions are for the bright part only.


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