NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-25 T02:07:52 PDT
Help | Comment | NED Home

Notes for object NGC 0247

13 note(s) found in NED.


1. 2007MNRAS.382.1552L
Re:NGC 0247
NGC 247: The colours of the bright central sources are consistent with their
being star-forming regions. Pa{alpha} emission is also seen in the central
regions (Boker et al. 1999). The nucleus of this galaxy appeared unresolved in
the UV (Maoz et al. 1995). Our spectral analysis implies a combination of young,
intermediate and old stars.

2. 2006AJ....131.1361K
Re:NGC 0247
NGC 247: Among the known galaxies in the Sculptor filament, this spiral
galaxy remained the last one without a reliable distance estimate. The
dimensions of NGC 247 (27' x 7') extend far beyond the ACS field. We
targeted the northern side of the galaxy at a distance of 6.5' from
the nucleus, which is relatively free from bright stellar complexes.
Nevertheless, about 1.7 x 10^5^ stars have been detected in this field.
The derived TRGB distance to NGC 247, 3.65 Mpc, agrees with the distance
estimate, 4.1 Mpc, obtained from the TF relation
(Karachentsev et al. 2003b).

3. 2005PNAOJ...8....1M
Re:KUG 0044-210
A number of blue knots are located on the galaxy plane.

4. 2000MNRAS.319...17L
Re:NGC 0247
NGC 247: Two strong X-ray sources are seen in the southern region of the
ROSAT HRI image (see Fig. 5). A 2{sigma} upper limit for a point source
located in the nuclear region of the galaxy can be found in Table 5. Read,
Ponman & Strickland (1997) report the detection of five ROSAT PSPC sources
associated with the galaxy, three of which lie outside our optical image.
The remaining two correspond to our sources X1 and X2. No obvious optical
couterparts are seen at these positions, although X1 is located at the
edge of a bright star-forming region. Notice that the astrometry of the
observations is thought to be accurate (Section 3.2.2).
From a fit in the 0.1-2.0 keV range, Read et al. (1997) found that the
PSPC spectrum of X1 indicates a very soft and obscured source
(kT = 0.12 keV, N_H_ = 6.4 x 10^21^ cm^-2^). Using their spectral
parameters, we find that the HRI count rate corresponds to a flux in the
0.1-2.0 keV energy range (corrected by Galactic absorption only) of
5.0 x 10^-13^ erg s^-1^ cm^-2^, compared with the PSPC flux of
2.1 x 10^-13^ erg s^-1^ cm^-2^ given by Read et al. This corresponds to
an increase in the source luminosity by more than a factor of 2 between
the PSPC and HRI observations. From the HRI count rate, the intrinsic
luminosity of the source is found to be ~10^42^ erg s^-1^ for an assumed
distance to NGC 247 of 3.69 Mpc, although variations in the adopted
parameters can change this significantly. For example, changing the
hydrogen column and temperature by 1{sigma} each (using the error bars in
Read et al. 1997, i.e., kT = 0.15 keV, N_H_ = 4.7 x 10^21^ cm^-2^)
decreases the luminosity by an order of magnitude. The very soft spectral
distribution, extremely high intrinsic luminosity, and detected variability
make this source a good candidate for a stellar accreting black hole.
Mackie et al. (1995) also report PSPC observations, and find a faint
nuclear source with L_X_ = 1 x 10^36^ erg s^-1^, which is well below
the detection limit of our HRI observations. However, due to the poor
spatial resolution of the PSPC, it is not clear whether this source is
coincident with the galaxy nucleus.

5. 1994CAG1..B...0000S
Re:NGC 0247
South Polar Group
Sc(s)III-IV
CD-512-S
Sep 28/29, 1978
103aO + GG385
45 min
NGC 247 is a highly resolved nearby galaxy
in the South Polar Group (de Vaucouleurs
1959a). Among members of the group are NGC 55,
NGC 247, NGC 253, NGC 300, and NGC 7793,
all in the RSA and all shown in this atlas.
The stellar content of NGC 247 is easily
resolved into individual stars, star clusters,
associations, and a few small HII regions. The
resolution begins at about B = 17 for the blue
supergiants. The distance modulus must be nearly
the same as that of NGC 300 (panels 261, S6)
at m - M = 26.5 from Cepheids (Graham 1984).
Hence the brightest blue supergiants have absolute
magnitudes of about M_B_ = -9.5, consistent
with the calibration given elsewhere (Sandage
and Carlson 1988). The redshift is small at
v_o = 227 km/s, consistent with the small distance
modulus.
The type is very late Sc. Note the small
nucleus and the absence of a central bulge.

6. 1985SGC...C...0000C
Re:NGC 0247
Plate 4496r
Pretty bright nucleus, short bar, patchy arms with many knots; partially
resolved. Superposed on group.

7. 1982ESOU..C...0000L
Re:ESO 004440-2102.0
=ESO 540- G 22
in foreground of cluster

8. 1976RC2...C...0000d
Re:NGC 0247
In the Sculptor Group.
HI 21cm:
Astr. Ap., 23, 295, 1973.
Search for Halo:
Astr. Ap., 28, 95, 1973.
HII Regions and Distance Modulus:
Ap. J., 194, 559, 1974.
Dynamics and Mass Determination:
Proc. A.S. Australia, 1, 288, 1969.

9. 1974UGCA..C...0000N
Re:UGCA 011
UGCA 011:
= NGC 0247

10. 1964RC1...C...0000d
Re:NGC 0247
In the Sculptor Group
along with NGC 0045, NGC 0055, NGC 0253,
NGC 0300, and NGC 7793 (Ap. J., 130, 718, 1959).
Extremely small, very bright nucleus, or star.
Low surface brightness.
Well resolved, emission-line objects
Asymmetric Mt. Wilson Velocity for bright emission patch
5.0 arcmin [south-following] nucleus: +1 km/sec.
Description and Drawing:
Helwan 9
Photometry:
Medd. Lund, II, 128, 1950.
HII Regions:
Zeit. fur Ap., 50, 168, 1960.
HI Emission:
Epstein, Harvard Thesis, 1962.

11. 1961AJ.....66..541B
Re:NGC 0247
3. NGC 55 Group
De Vaucouleurs (1959) has argued that NGC 45, 55, 247, 253, 300, and 7793 form a
physical group about 8X 10^5^ pc in diameter. The group is only about 2.5 X
10^6^ pc distant and the galaxies are all spirals. The argument for their
forming a physical group is based on their distribution among the other bright
galaxies in the southern hemisphere. From the radial velocities, de Vaucouleurs
showed that the virial theorem would not be satisfied unless the average masses
of the galaxies were in excess of 10^12^ M_sun_, with a mass-to-light ratio
greater than 500. Thus if the galaxies form a physical group, it must be
expanding, unless there is a large concentration of intergalactic matter.

12. 1959ApJ...130..718D
Re:NGC 0247
NGC 247
The velocity + 1 +/- 35 km/sec measured by Humason on a low-dispersion Mount
Wilson spectrogram refers to an emission patch 5'0 south-following the nucleus.
The location of the object in this tilted system is such that about half the
rotational velocity, Vr, is reflected in the observed radial velocity, Vo, and,
if the arms are trailing, the velocity at the center is V_s_ = Vo + (1/2)Vr. NGC
247 is rather similar to M33 in type, absolute magnitude, and dimensions; its
apparent dimensions are about five times smaller; in M33 the rotational velocity
25' from the center is about 100 km/sec; if the circular rotational velocity is
the same 5'0 from the center of NGC 247, the systemic velocity is then V_s_ = 1
+ 50 ~ 50 km/sec. This "rectified" value with an estimated p.e.+/- 50 km/sec,
admittedly uncertain, will be used in the discussion.

13. 1918PLicO..13....9C
Re:NGC 0247
A faint, very large, spiral, 18' x 5' in p.a. 175^deg^ Nucleus stellar; many
almost stellar condensations. Whorls somewhat irregular, and indistinct. 22 s.n.


Back to NED Home