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Date and Time of the Query: 2022-01-20 T06:48:41 PST
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Notes for object NGC 1553

15 note(s) found in NED.


1. 2006ApJ...647..140F
Re:NGC 1553
This galaxy (L2/T2, S0) has three point sources in its central kiloparsec. The
brightest one is exactly at the center of the galaxy, and its spectrum is well
fitted by either a two-temperature plasma model (kT_1_ = 0.14^+0.04^_-0.09_ keV,
kT_2_ = 18.0^+70^_-10.4_ keV) or a power law ({GAMMA} = 1.2^+0.2^_-0.1_). The
preference of a two-temperature over a one-temperature plasma model and a
power-law model is justified by the F-test. Both of the above models give a
luminosity of L_0.5-10 keV_ = 1.5 x 10^40^40 ergs s^-1^. With such a luminosity
and spectral characteristics, this source is probably an AGN. This is supported
by observations in the radio band: NGC 1553 is a weak radio source (10 mJy at
843 MHz; Harnett 1987). Assuming a radio spectral index of {rho} = -0.5 (adopted
as our default value hereafter, where S_{nu}_ is proportional to {nu}^{rho}^),
we calculate the radio flux at 5 GHz to be S_5_ Ghz = 4.1 mJy and log R_X_ =
-2.7, which means that this source is radio-loud. Blanton et al. (2001) came to
the same conclusion on the nature of the central source using the same data set,
but they estimated its luminosity to be slightly higher (L_0.3-10 keV = 1.75 x
10^40^ ergs s^-1^). We evaluated the luminosity of the central 2.5" region to be
L_2-10 keV_ = 1.6 x 10^40^ ergs s^-1^. The luminosity of the AGN is evaluated by
integrating the power law that fits the data to be L_2-10 keV_ = 1.5x10^40^ ergs
s^-1^, which means that the AGN is the source of 92% of the X-ray luminosity
from the central region. This is consistent with estimates of the age of the
stellar population that indicate that the stars in the nucleus of NGC 1553 are
old (>17 Gyr, Terlevich & Forbes 2002; 10-15 Gyr, Longhetti et al. 2000).

2. 2006ApJ...639..136H
Re:NGC 1553
NGC 1553. We extracted the spectrum from a 2' (10 kpc) aperture, excluding
data in the vicinity of the central LLAGN. The Chandra image reveals
remarkable structure (a striking S-shaped pattern, which may be related to
interaction with the central AGN; Blanton et al. 2001). Blanton et al.
(2001) reported Z_Fe_ = 0.17 for the hot gas, using the Chandra data,
which agrees very well with our fit with a single ~0.4 keV gas component.
We do not find any evidence of a hard component, such as reported by these
authors, in addition to the hot gas and point-source components. However,
if we include a small amount of flaring-contaminated data, such a
component is required. Given the low abundance and the complexity of the
ISM, we experimented with the addition of a second (kT ~ 0.86 keV) gas
component. It did not improve the fit appreciably (delta chi^2^ ~= 2), but
Z_Fe_ was significantly increased to 0.24^+0.64^_-0.11, and ZNe/Z_Fe_
reduced to 0.67^0.100^_-0.57_. The very low abundance we obtain for this
galaxy may, therefore, be mitigated by the Fe bias. However, the data do
not require such an additional hot gas component.

3. 2006AJ....132.2634L
Re:NGC 1553
The dominant feature of this galaxy's morphology is a strong inner ring/lens
(Sandage & Brucato 1979; Kormendy 1984). The lens shows subtle structure in our
K_s_-band image and is classified as an inner ring in RC3. BCO06 give a type of
SA(rl)0+ to highlight that the feature really is more a ring than a lens. In the
central part of the galaxy a second elongated feature is present, which in our
unsharp mask (Fig. 5) appears to be a nuclear disk showing spiral arms. Sandage
& Bedke (1994) noticed that this galaxy has subtle dust lanes in the disk,
leading to its classification as a peculiar SB0/Sa. The major-axis rotation
curve for this galaxy is found to be typical for S0 galaxies (Kormendy 1984;
Rampazzo 1988). Contrary to all previous evidence, SGA04 reclassified NGC 1553
as an elliptical with an inner disk, a choice that was justified by the fact
that their decomposition did not find any outer disk. No B/T ratio is given by
SGA04, but the shape parameter of the bulge was found to be n = 5.2 4. In our
analysis the presence of the inner disk is obvious: it is particularly clearly
visible in the image in which the exponential disk is subtracted, shown in
Figure 5. The best 2D solution was found by fitting a bulge, lens/ring, and an
outer disk, which appeared to be exponential (as in the {mu}-profile by Kormendy
1984). We found B/T = 0.21 and n = 1.9. Again, in order to duplicate the 2D
solution of SGA04 we also made a 2D bulge-disk decomposition; this gives B/T =
0.88 and n = 3.33, which is exactly the same result as that obtained by our 1D
method for this galaxy. The reason for the very large difference between our
two- and three-component decompositions is that in the two-component solution
the flux of the lens goes erroneously to the bulge. In all our decompositions
the shape parameter of the bulge is considerably smaller than the value n = 5.24
obtained by SGA04. The nature of the bulge in this galaxy is unclear even in our
best-fitting solution. The component that is fitted as a bulge is actually the
inner disk, and there is no other more spherical component in the central
regions that could be interpreted as a bulge. Perhaps there is no bulge in this
galaxy, unless the inner disk is interpreted as a pseudobulge. Kinematical
evidence for this interpretation comes from the study by Kormendy (1984), who
argued that the bulge (the small central component) is cooler than the lens that
dominates at larger radial distances. The change in the stellar velocity
dispersion occurs at r = 12" - 15", after which the lens starts to dominate.
This is precisely the distance inside of which we find the disklike bulge in our
decomposition.

4. 2005ApJS..157...59L
Re:NGC 1553
ULX1 and ULX2 are within the D_25_ isophote in this lenticular galaxy at a
distance of 18.54 Mpc.

5. 1998A&AS..130..267L
Re:NGC 1553
Differently from the companion NGC 1549, the geometry of NGC 1553 is
characterized by a nearly constant position angle. The extended velocity
curves studied by Kormendy (1984) and Rampazzo (1988), along PA = 149.5
^deg^ and PA = 140 ^deg^ respectively show a secondary maximum (~ at
10"), visible also in our velocity curve. No rotation is measured by
the previous authors along the minor axis (PA = 59.5 ^deg^; PA = 50
^deg^ axes respectively) confirming that NGC 1553 is a lenticular galaxy.
PS96 report 185 km s^-1^ as the average value in literature for the
central velocity dispersion in good agreement with our nuclear value.

6. 1994CAG1..B...0000S
Re:NGC 1553
Dorado 37
S0_1/2_(5) pec
(P)
CD-651-Br
Jan 5/6, 1979
103aO + GG385
10 min
NGC 1553 forms a pair with NGC 1549
(E2; panels 5, S1) with a projected angular
separation of 11.5'. The redshifts, corrected to
the centroid of the Local Group, are v_o(1549) =
991 km/s and v_o(1553) = 1053 km/s. The
galaxies clearly form a physical pair. The redshift
distance of 20 Mpc (H = 50) gives a projected
linear separation of 67 kpc.
The subtle lanes (dust?) in the disk and the
bright boundary lane at the rim of the disk are
the reasons for the mixed S0_1/2_ classification.

7. 1994A&AS..105..433L
Re:NGC 1553
NGC 1553 (Fig. 10); it is an S0 galaxy with an unusually large lens,
which influences the brightness profile from 20" to ~ 40" from the
center, the outer part being dominated by the exponential disk (see
Kormendy 1984 and references therein). The rotation curve along the major
axis (PA=151^deg^) has the typical shape of an early S0. There is a first
maximum at ~8" from the nucleus, possibly followed by a minimum at 15".
Then the velocity seems to stabilize. The velocity dispersion remains
almost constant in the inner ~ 5" and then decreases to reach ~ 150 km
s^-1^ at 30" from the center. In our data there is no clear evidence for
the slight increase found by Kormendy (1984) at r ~ 12"-15" and
interpreted as the inner part of the lens being hotter than the bulge.
The velocity dispersion profile has the same behaviour along the minor
axis (PA = 61^deg^), where no rotation is present. Rampazzo (1988) finds
a similar behaviour in the velocity dispersion profile at PA 140^deg^,
but his maximum is less prominent.

8. 1994A&AS..105..433L
Re:NGC 1553
NGC 1553 (Fig. 10); it is an S0 galaxy with an unusually large lens,
which influences the brightness profile from ~20" to ~40" from the
center, the outer part being dominated by the exponential disk (see
Kormendy 1984 and references therein). The rotation curve along the major
axis (PA=151^deg^) has the typical shape of an early S0. There is a first
maximum at ~8" from the nucleus, possibly followed by a minimum at 15".
Then the velocity seems to stabilize. The velocity dispersion remains
almost constant in the inner ~5" and then decreases to reach ~150 km
s^-1^ at 30" from the center. In our data there is no clear evidence
for the slight increase found by Kormendy (1984) at r~12" divided by 15"
and interpreted as the inner part of the lens being hotter than the
bulge. The velocity dispersion profile has the same behaviour along the
minor axis (PA= 61^deg^), where no rotation is present. Rampazzo (1988)
finds a similar behaviour in the velocity dispersion profile at
PA 140^deg^, but his maximum is less prominent.

9. 1993ApJS...86....5K
Re:NGC 1553
NGC 1553; S0 pec.
The UV spectrum has weak flux below the main-sequence turnoff at ~2400A,
which is typical of an older intermediate population present in quiescent
S0 galaxies (Gregg 1989). There is an increase in flux in the spectrum at
wavelengths below 1400 A (cf. Burstein et al. 1988 for analogous
behavior among elliptical galaxies, the "rising branch"). This galaxy is
at sufficiently high redshift (z = 0.004) that the intrinsic Mg II
absorption feature is separated from the Galactic feature by 11 A.

10. 1985SGC...C...0000C
Re:NGC 1553
Plate 1893
Overexposed center, pretty bright lens 4.5 x 2.8, very faint corona.
Interacting pair with NGC 1549 11.7 north-preceding.

11. 1982ESOU..C...0000L
Re:ESO 041505-5554.2
=ESO 157- G 17
in group
stars superimposed

12. 1979AJ.....84..472S
Re:NGC 1553
One of the most extreme known examples of
a high-surface-brightness lens of small intensity gradient within
which a much higher surface brightness central region exists.
The prominence of the lens is well shown in the microphotometer
tracing given by Freeman, K.C. 1975, Dynamics of Stellar Systems,
IAU Symp. No.69, ED. A. Hayli, (Dordrecht: Reidel), p. 367.
At the edge of this lens appears a remarkable intensity enhancement
consisting of two segments of a broken thin ring, inside of which
are very subtle thin dust lanes.
The regular ring segments are so unusual as to warrant the pec listing.
This is a much earlier example of the internal ring
such as is present in NGC 3275, but there it is lumpy in
NGC 3275 because of the young hot stars.
The lens is more prominent in NGC 1553
than in any other in the Shapley-Ames catalog.
Morphology is similar to (but more extreme than) VII Zw 793
studied by Kormendy, J. 1977, Ap. J., 214, 359. (his Figure 3f)
Quite similar to IC 2035 described here.

13. 1976RC2...C...0000d
Re:NGC 1553
Pair with NGC 1549 at 12 arcmin north-preceding.
IC 2058 is 21.5 arcmin south-following.
Photograph:
M.N.R.A.S., 131, 351, 1966.
J.R.A.S. Canada, 68, 117, 1974.
Photometry:
Atlas Gal. Austr., 1968.
Spectrum: Discordant V = +1035 km/sec;
Source M (M.N.A.S.S.A., 22, 100, 1963) rejected.

14. 1964RC1...C...0000d
Re:NGC 1553
Extremely bright nucleus.
Lens: 1.8 arcmin x 1.0 arcmin.
Slight brightening at rim of lens forms
Faint (r): 1.2 arcmin x 0.7 arcmin.
Non-interacting pair with IC 2058 at 21.5 arcmin.
Photometry:
M.N.R.A.S., 111, 526, 1951.
Spectrum:
Mem.R.A.S., 68, 69, 1961.

15. 1957HPh....53..275d
Re:NGC 1553
SA(r)0^o
(Plate 7)
A weak trace of a ring appears at the edge of the lens.
Note the small, distinct nucleus in the lens, and the faint
outer envelope.
Compare with NGC 4459 (Plate 3), NGC 7166 (Plate 6), and
NGC 7702 (Plate 8).


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