Date and Time of the Query: 2019-08-17 T15:35:37 PDT
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Notes for object PKS 0500+019

15 note(s) found in NED.

1. 2004A&A...424...91E
Re:PKS J0503+0203
J0503+0203: VLBI images of this CSO are given by Fey & Charlot (2000),
Fomalont et al. (2000) and Stanghellini et al. (2001).

2. 2002A&A...386...97J
Re:PKS B0500+019
Galaxy identification from CCD imaging, extended and diffuse on B
frame, very much brighter on Gunn-i and Gunn-z. The host is a
narrow-line radio galaxy with a redshift of 0.582 (Paper II); it is a
well-known Gigahertz-Peak-Spectrum (GPS) source v (1990), although
included in the study by Kollgaard et al. (1995ApJ...449...61K) of
``optically-quiet quasars''.

3. 2002A&A...381...13C
Re:PKS 0500+019
0500+019: In spite of the poor seeing conditions in which our CCD material
was obtained, our images show evidence of structure. See extensive note by
Fugmann et al. (1988), who barely resolved the optical counterpart. For
this source we obtain very high radio-optical RA and DEC residuals, which
could probably be attributed to our mediocre observational material.
Drinkwater also obtains large residuals for this object, but they are
completely inconsistent with ours.

4. 2001A&A...377..377S
Re:TXS 0500+019
0500+019: we consider the radio source to be associated with a galaxy at
z = 0.583 rather than a background quasar (cf. Stickel et al. 1996a, and
see also Paper I for references on individual objects). The radio source
is S-shaped as is sometimes found among GPS radio galaxies, with the
northern part brighter than the southern part. Polarized emission is
detected at a low fractional level (~0.3% at the total intensity peak
position in PA +101) only in the brightest component. The VLA total
fractional polarization at 5 GHz is below 0.1% (the reference for total
fractional polarization here and for the other objects is Stanghellini
et al. 1998). The spectral index image shows that a clear flat-spectrum
region is not present, the flattest spectral index being close to the
brightest component B. The low resolution image does not permit us to
separate the contribution of the subcomponents B1 and B2, but we see
slightly darker shades just south of the peak intensity on the low
resolution image, and we suspect the flattest component is component B2.
Therefore, if the core is located in component B2 or close to it, this
radio source would be a genuine CSO. This classification is in agreement
with the MEM image showing compact subcomponents corresponding to B1 and
B2, and extended regions at the edges of the radio source.

5. 2000A&AS..143..181D
Re:PKS 0500+019
0500+019 This source has already been described in Paper I, but Stickel
et al. (1996) later suggested the GPS source to be a background quasar,
based on a single unidentified emission line at 6543A. Our 1995 redshift
measurement (z=0.583) would therefore be of an intervening galaxy.
However, we do not see any evidence of this 6543A line in our spectrum,
nor does our Hubble Space Telescope NICMOS J and K band data show a hint
of this quasar-galaxy superposition (cf. De Vries 1999). The recent H I
absorption redshift of 0.58472 (Carilli et al. 1998) is therefore
intrinsic and not due to an intervening absorber, as Stickel et al.

6. 1998ApJ...503..138D
Re:PKS 0500+019
0500+019 (OG 003); GPS (z = 0.583).-There is some controversy about
the nature of this source. Stickel et al. (1996) claim that this source
is a superposition of a foreground galaxy and a background quasar. The
alignment has to be near perfect, since the quasar and galaxy nuclei
coincide on the plane of the sky. It does, however, neatly explain the
anomalous position of the source in the J_ext_ versus K_ext_ plot
(Fig. 3). Because of the high nuclear absorption by the foreground
nucleus, the background quasar only becomes prominent at the near-IR
wavelengths. All this is based on an unidentified emission line in
their spectrum (Stickel et al. 1996), not seen (at that level) in
previous spectra (de Vries et al. 1995; Kollgaard et al. 1995), casting
some doubt on the proposed model. We suggest 0500+019 is a "red quasar"
intrinsic to the z = 0.583 galaxy.

7. 1998A&AS..129..219D
Re:PKS 0500+019
0500+019 [G, z = 0.583]
There has been some debate on the optical identification: formerly associated
with a quasar by Fugmann & Meisenheimer (1988), now the radio source host has
been classified as a galaxy at z=0.583 by de Vries et al. (1995).
The source was not resolved with VLBI by Hodges et al. (1984) at 18 cm. Whilst
the structure is barely resolved at S band (with F_S_~65%), at X band (Fig. 2)
the radio emission shows two very asymmetric regions separated by~10 mas in
PA~-180^deg^ and accounting for almost the whole flux density. Our data are
consistent with a global VLBI image at 5 GHz by Stanghellini et al. (1997). The
integrated radio spectrum peaks around 3 GHz and is rather flat at dm
wavelengths and is similar to that presented by O'Dea et al. (1990). There is a
significant steepening in the high frequency end ({alpha}~0.9 between 10.7 and
31 GHz). Millimeter observations reported by Wiren et al. (1992) are suggestive
of an increased flux density at high frequencies, with a possible flattening of
the spectrum.

8. 1997A&A...325..943S
Re:PKS 0500+019
Fugmann and Meisenheimer (1988) found the optical counterpart of 0500+019 to be
a pointlike source with a nearby extended companion. while di Serego Alighieri
et al. (1994) found it slightly resolved. De Vries et al. (1995) consider the
parent object a galaxy and measure a redshift of z=0.583. Stickel et al. (1996)
find an asymmetric galaxy of magnitude m_R_=20.7 as the optical counterpart of
thc radio source and find the morphology dominated by a point source in the
infrared ({lambda}=2.16 microns). They also find in addition to the z=0.583
redshift system, an unidentified emission line at 6543A not seen in the
spectrum previously presented by de Vries et al. (1995). Stickel et al. (1996),
based on the detection of the emitting line, to the pointlike VLBI morphology
(Hodges and Mutel 1984), and the flux density variability at 22 GHz [Sic] from
Stanghellini et al. 1990, suggest that the radio source is associated with a
background quasar.
Our image (Fig. 5) resolves the structure of 0500+019 revealing an S-shaped
morphology oriented in the NS direction accounting for the whole VLA flux
density. The large flux density variability at 22 GHz stated by Stickel et al
(1996) is probably based on a misunderstanding of the data in Stanghellini et
al. (1990) where the flux densities given are referred to the wavelength, not
to the frequency. At 5 GHz where many flux density measures are available the
radio source is stable within the errors (Perley 1982, Kuhr et al. 1981, O'Dea
et al. 1990). Therefore we prefer the association of the radio source with the
galaxy at z=0.583 rather than with the background candidate quasar at an
unknown redshift. The weak emission line seen at 6543A by Stickel et al. (1996)
could well be an artifact or a local fluctuation of the noise, and the
existence of a background quasar requires further confirmation.
It is difficult to provide a morphological classification with an image at a
single frequency, but the radio structure is symmetric and is dominated by
components similar to jets and/or micro-lobes with the possible presence of a
weak core. Such an S-shaped structure is commonly found among GPS radio
galaxies (Taylor et al. 1996) and symmetric or quasi-symmetric structures are
preferably found in galaxies rather than in quasars (Dallacasa et al. 1995).
This is also evident in other sources of the small sample presented here.

9. 1996ApJ...468..556S
Re:PKS 0500+019
0500+019.--The source appears to be moderately variable; the infrared image
indicates no significant interference with the aperture photometry from nearby
sources. Fugmann, Meisenheimer, & Roeser (1988) described the optical
counterpart as an unresolved QSO lying only 2" north of a galaxy. The imaging
data shown in Stickel et al. (1995) and in a deeper R-band image from 1995
February, however, show only an asymmetric extended galaxy without a noticeable
point source, while a strong point source has been detected in the infrared
image. The differences in optical morphology could be due to variability. The
optical spectrum shows narrow, moderate-excitation emission lines and Ca II
absorption at z=0.583 as well as an additional unidentified emission line of
unknown redshift (Stickel et al. 1995). The infrared spectrum is relatively flat
(spectral index {alpha}=-1.4), but Fugmann & Meisenheimer (1988) find that the
optical SED is extremely steep, consistent either with an exponential cutoff or
with very strong reddening. From the optical and infrared morphology in
conjunction with the optical spectrum, it seems likely that the very steep SED
is caused by reddening in the galaxy, and it is possible that the QSO lies
behind it rather than within it.

10. 1996A&AS..115...11S
Re:PKS 0500+019
0500+019: Our CCD image shows an optical counterpart at the radio position,
but it is neither deep enough nor has sufficient spatial resolution to allow
the discrimination between resolved or stellar and to show the presence of two
objects, as described by Fugmann et al. (1988). The classification and optical
magnitude listed in Table 1 has been taken from Fugmann et al. (1988). In
contrast, the optical counterpart has been described to be extended and
classified as a galaxy by di Serego Alighieri et al. (1994).

11. 1995ApJ...449...61K
Re:PKS J0503+0203
0503+020.-This source is reported to have a gigahertz-peaked radio
spectrum, low radio polarization, slight variations at millimeter
wavelengths, and a detection with the Einstein Observatory (Ledden &
O'Dell 1983; Gregorini et al. 1984; O'Dea et al. 1990; Wiren et al.
1992). Our radio measurements show only an unresolved core with a
spectral index {alpha}_r_ = -0.6 above 1.4 GHz. An optical image shows
several faint objects around the AGN, including one 2' to the south, and
it is possible 0503+020 lies in the outer portion of a cluster (Fugmann,
Meisenheimer, & Roser 1988). Our optical spectrum (Fig. 2b) shows a very
red continuum with a weak emission feature at roughly 7920 A, and two
weaker features at 7852 A and 5890 A. The 5890 A feature may be spurious,
as it lies very near the night sky and city light NaD emission line which
is extremely strong at Lick Observatory, and is consequently difficult to
subtract properly. We tentatively identify these features with
[O III] {lambda}{lambda}4959,5007 and [O II] {lambda}3727 and estimate a
redshift of z = 0.58; it should be emphasized that this redshift is
uncertain. The optical continuum is very red with {alpha}_0_ = -5. As
with 0409+123, the ROSAT spectrum (Fig.1b) is consistent with either
significant excess absorption or a very hard spectrum. With X-ray
emission far above the extrapolation of the remarkably red optical
continuum and C = 1.2, we confirm that this object is an OQQ.

12. 1995A&AS..114..259d
Re:PKS 0500+019
0500+019: Our optical identification agrees with Fugmann et al.
(1988). We measure a redshift of z = 0.583 (see below).

13. 1994MNRAS.269..998d
Re:PKS 0500+019
This compact radio source was identified by Fugmann et al. (1988). Our
CCD frame shows their object 1 to be slightly resolved, and its spectrum
has a faint red continuum with possible emission lines at 5910 and 6400A.

14. 1994A&AS..105..211S
Re:[KWP81] 0500+01
The identification and magnitude were taken from Fugmann et al. (1988).
The same optical counterpart has also been found by Torres & Wroblewski
(1987) and was described as very faint and of unknown type.

15. 1993MNRAS.263.1023M
Re:PKS 0500+019
0500+01. O'Dea, Baum & Stanghellini (1991) classified this compact source
as GPS.

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