Date and Time of the Query: 2019-05-20 T01:49:22 PDT
Help | Comment | NED Home

Notes for object 3C 147

15 note(s) found in NED.

1. 2004ApJS..155...33S
Re:VSOP J0542+4951
(3C 147) The source is composed of a core component with diffuse
emission to the west. See also the VSOP image from Slysh et al.
(2001). The area subtended by the core is less than 0.10 mas^2^.

2. 2003MNRAS.346.1009H
Re:3C 147
3C 147. It is unclear if the very broad feature surrounding the H{alpha}
line is real, and if so, what its origin is. It is possible that it is
simply an artefact generated by failure of the flux calibration process
near the band edges; on the other hand, it may be a broad wing of
H{alpha}. The error on the total H{alpha} flux is larger than usual
(probably 30-40 per cent) owing to difficulty in fitting to the
continuum at the blue end of the spectrum. The noise to the red end of
the optical part of the composite is due to coincidence with a set of
strong sky emission lines. We can join our 3C 147 spectrum to the
optical spectrum of Jackson & Browne (1991) giving us confidence in the
flux calibration of our IR data - the power law optical continuum
matches up in both spectral index and magnitude between the two
spectra. The composite spectrum thus obtained is shown in Fig. 3.

3. 2000ARep...44..286T
Re:3C 147
3C 147
This is a quasar with redshift z = 0.545. Observations at 22.5, 15,
8.4, 5, and 1.6 GHz with resolution ~0.1" show a weak, extended component
to the north and a stronger, more compact structure to the south,
stretching 0.25" from northwest to south-east. Observations with resolution
~0.02" indicate that the southern component has a core-jet structure
surrounded by a weak halo. The core, which is at the southern end of the
jet, is very compact (~0.005" x 0.002") and contributes most of the flux
density from compact emission at 1.67 GHz. Superluminal expansion has been
observed in the core. A comparison of the core and jet at 1.67 GHz,
609 MHz, and 329 MHz showed that the shape and size of the jet are the same
at these three frequencies, but its relative contribution to the total flux
changes. At 1.67 GHz, the core contributes most of the compact flux
density, while the flux densities from the core and the two knots
dominating the jet emission are comparable at 329 MHz. Unfortunately, many
papers dealing with high-resolution observations do not present estimates
for the flux densities of individual features, forcing us to estimate these
flux densities from the radio maps presented.
We observed 3C 147 over six days at elongations ~29^deg^. This is the
strongest source in our sample, both in terms of its integrated flux
density (S_int_ = 84 Jy) and the flux density of the scintillating
component (S_scin_ = 39 Jy, for {theta} ~ 0.2"). Figure 3 presents an
example of a recording for 3C 147. The scintillations are clearly visible,
even in the sidelobes of the antenna. There is an appreciable turnover in
the integrated spectrum, due to a turnover in the spectrum of the compact
features. However, we were not able to construct a trustworthy spectrum
including our measurement. It appears that this is one of relatively few
cases in which the components dominating the scintillations are negligible
at high frequencies. Therefore, we used the spectrum presented in to
estimate the physical conditions in this source.

4. 2000AJ....120.2284A
Re:3C 147
The emission-line morphology of 3C 147 is also dominated by an
unresolved central source, embedded in a more diffuse region, which is
elongated along P.A. +30^deg^ and extends over ~1.2", approximately
symmetric with respect to the center of the continuum emission. Along
the same axis, ~1.8" south from the nucleus, there is a faint arclike
structure. Note that the two compact knots at the eastern edge of this
arc are continuum features (see Fig. 8). The emission-line arc extends
over ~1.3" and spans P.A. ~185^deg^ to P.A. ~230^deg^. Another galaxy,
possibly a companion, is located 3.9" away at P.A. 190^deg^.
The double radio structure (van Breugel et al. 1984) is oriented
along P.A. ~+30^deg^ and extends over ~1", and it is therefore well
aligned and essentially cospatial with the line emission. The southern
component envelopes a very bright jet. The radio core is well separated
from the surrounding bright 3C 147 steep spectrum emission at high
resolution only (Zhang et al. 1991).

5. 2000A&AS..145....1P
Re:3C 147
0538+498 (3C 147): This quasar (z=0.545) shows no flux variations as
expected. It has been used as a primary flux calibrator;

6. 1998MNRAS.299..467L
Re:3C 147
3C 147. The total intensity structure of this quasar has been studied in
detail by MERLIN (Akujor, Spencer & Wilkinson 1990) and the EVN (Zhang
et al. 1991). The new MERLIN 5-GHz map shows the diffuse northern lobe
and the jet to the south-west of the core, surrounded by diffuse
emission. The source is barely polarized at 5 GHz, but VLA images at
8.4 and 15 GHz (Akujor & Garrington 1995) show significant polarization
in the northern lobe, indicating that this lobe is depolarized at 5 GHz.

7. 1998A&A...332...10M
Re:3C 147
3C147 (0538+498)
3C147 has been observed by several investigators; see, for example, the
collection of images by Alef et al. (1990). Those authors have also observed
3C147 with 5 GHz VLBI over three epochs. The source shows an unusually-complex,
nonlinear structure which varies with time. Superluminal separation of two
components in the core region was observed also. New 8.4 GHz data (Alef, private
communication) confirm a mildly-superluminal separation velocity of
v_app_~1.3c/h. The jet is embedded in a diffuse emission region and shows a
change in the projected orientation of its major axis of 90^deg^ at ~200 mas
from the core. A VLA image at 1 GHz (van Bruegel et al. 1984) shows a weak
component north to the main one in a position which is opposite to the jet
respect to the core. 3C147 shows large RM's of -3144 and +630 rad m^-2^ in the
rest frame of the source for the main component and for the extension to the NNE
respectively (Junor et al. submitted).

8. 1997ApJS..110..191d
Re:3C 147
3C 147 (quasar, z = 0.545, m_F702W_ = 17.21).-Our image is dominated by
the PSF. The two bright spots to the south of the source may be companion
objects possibly associated with the quasar. Superluminal motion has also
been detected in this source (Alef, Preuss, & Kellermann 1990).

9. 1995A&AS..112..235A
Re:3C 147
3C 147 (0538+49)
The extension to the south-east of this source is highly polarized, but
at this resolution the polarization in the jet is low at 8.4 and 15 GHz.

10. 1994ApJS...93....1A
Re:3C 147
Q0538+4949 (3C 147, z_em_ = 0.545)
We find no published spectra and no absorption lines in our spectrum.

11. 1994ApJS...91..491G
Re:3C 147
0538+498 (3C 147) - [O III] {lambda}4959 is lost to atmospheric A-band
absorption. The wing of this absorption feature reaches under the blue
wing of [O III] {lambda}5007, but was corrected prior to profile

12. 1994A&AS..105...91B
Re:3C 147
0538+498 (3C 147, Fig. 12) Radio data at sub-arcsecond resolution of this
CSS (Compact Steep Spectrum) quasar can be found at many places in the
literature, e.g. in van Breugel et al. (1984; 15 GHz VLA map), Pearson et
al. (1985; 8.4 GHz VLA A array map), Spencer et aI. (1989; VLA maps at
4.8 and 15 GHz), Akujor et al. (1990; MERLIN maps at 151, 408, 1666, and
4995 MHz), and van Breugel et al. (1992; 22.5 GHz VLA map). Our 15 GHz
observation does not resolve the source: published higher resolution
observations reveal a complex, two-sided structure.

13. 1992A&A...256...56v
Re:3C 147
3C 147 (Fig. 12): Akujor et al. (1990), from MERLIN observations at 151
MHz, found a faint halo of 10" around the main component. Our 1.5 GHz
data, with a dynamic range of 7000:1 in the B-configuration map, and a
similar resolution, do not show any evidence for this halo. The
comparison between the A- and B- configuration flux densities also shows
no evidence for the halo. A comparison with total power flux measures
(quoted in Kuhr et al. 1981) is inconclusive. Therefore the spectrum of
any halo component must be very steep.

14. 1988ApJ...328..114P
Re:3C 147
0538+498 (3C 147).-3C 147 is an archetypal example of a steep-spectrum
compact source, and it has been well studied by many workers. In view of
this, we did not make 5 GHz observations of this object as part of our
survey. Nevertheless, it is part of our complete sample, and we
therefore discuss it here for completeness.
The large-scale structure of 3C 147 has been mapped using the VLA at
4.9 and 15.0 GHz by Readhead, Napier, and Bignell (1980), at 15.0 GHz by
van Breugel, Miley, and Heckman (1984), and at 5 GHz by Pearson, Perley,
and Readhead (1985). There is also a 5 GHz MERLIN map by Wilkinson et
al. (1984c). In addition there are observations at 81.5 MHz, both by
interplanetary scintillations (Readhead and Hewish 1974) and by
long-baseline interferometer (Hartas et al. 1983). These observations
all reveal emission over about 0.5" (2 kpc), with greatest extension in
P.A. 20deg. There is no evidence of any larger scale structure, so the
radio source is presumably much smaller than any host galaxy (in
projection, at least). The spectrum has a peak at 120 MHz, and a
low-frequency cutoff which is generally attributed to synchrotron
self-absorption (Scott and Readhead 1977).
There have been many VLBI observations of 3C 147, including the first
hybrid maps to be made by VLBI (Wilkinson et al. 1977). It has been
mapped at 327 MHz (Simon et al. 1983), 609 MHz (Wilkinson et al. 1977),
1661 and 1671 MHz (Readhead and Wilkinson 1980; Simon, Readhead, and
Wilkinson 1984), and 5 GHz (Preuss et al. 1984). Above 5 GHz it is
heavily resolved, and therefore difficult to observe. The VLBI
observations at frequencies up to 1671 MHz reveal a one-sided core-jet
structure, with the jet extending 0.2" (~1 kpc) to the southwest of the
core. At the extreme southwestern end the jet bends through 90deg
northward over a distance comparable to the width of the jet and then
rapidly fades. Such rapid fading in the vicinity of a bend is also seen
in 3C 309.1. The width of the jet is ~20 mas (75 pc), and is well
resolved. There are a number of distinct regions of higher brightness
along the jet. The core is heavily resolved in all directions. It is
about 5 mas across and roughly circular. The structure of the core
changes at both low frequencies (Simon et al. 1983) and high frequencies
(Preuss et al. 1984), but it is complex, and no simple pattern has
emerged. The low-frequency variability may be attributable to refractive
effects in the interstellar medium (Rickett, Coles, and Bourgois 1984;
Blandford and Narayan 1985), or it could represent intrinsic variations
enhanced by Dopper boosting (Simon et al. 1983).
The VLA and MERLIN maps show that the "large-scale", 0.5", structure is
on the side of the core opposite the jet. There are also faint
extensions toward the east. The overall morphology of 3C 147 is
mysterious. With its well-collimated jet, diffuse core, and apparent
lack of outer lobes, it does not fit into the pattern of either the
extended double sources or the compact objects.
Where necessary, we have assumed H_0_ = 100h km s^-1^ Mpc^-1^
and q_0_ = 0.5 to convert angles to projected distances.

15. 1964ApJ...140...35M
Re:3C 147
No. 17.-Redshift by Schmidt (Schmidt and Matthews 1964).

Back to NED Home