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Notes for object 3C 380

17 note(s) found in NED.

1. 2006MNRAS.366..339B
Re:3C 380
3C 380. The strong pileup for this source led us to mask a central circle of
radius 1.5 arcsec. Our result is in agreement with that found by Prieto (1996)
using ROSAT data ({GAMMA} = 1.58+/-0.13) and consistent with the photon index
recently published by Marshall et al. (2005): {GAMMA} = 1.61+/-0.09. However,
there is a discrepancy between our and their measure of the X-ray flux. We and
Marshall et al. (2005) extracted the spectrum from the same area; we used
slightly different background, but the background is negligible for such a
high-flux source. However, the big difference between the two studies is the
calibration. Our newer analysis has taken into account the charge transfer
inefficiency and the ARF is better determined. Moreover, without using a pileup
model, Marshall et al. (2005) found a poor fit, with a spectrum that was
inconsistently flatter than that in the current work, and consequently a lower
1-keV flux density. Marshall et al. (2005) attributed the flat spectrum and bad
fit to pileup, but the improve d calibration now available allows a more precise
flux density to be determined.

2. 2005ApJS..156...13M
Re:[HB89] 1828+487
3.3.17. 1828+487 = 3C 380 The radio polarization electric vectors are
parallel to the direction of the 2" long inner jet, oriented at
a position angle of -40deg. A parsec-scale superluminal radio jet
(Polatidis & Wilkinson 1998) is aligned with this arcsec-scale jet. The
Chandra point spread function is just small enough to provide a
detection of a knot in the inner jet about 1.8" from the core
coincident with the inner radio jet (Fig. 1q). See also the radio and
X-ray profiles (Figs. 2 and 3).

3. 2005A&A...443...61O
Re:3C 380
B.10 3C 380 No host is detected in R band for this object at z=0.692, though it
is clearly present in V and I band. However, there is an off-centred structure
visible in all bands, which coincides with the two optical synchrotron hotspots
detected by de Vries et al. (1997) with HST. There is very little
[OII]{lambda}3727 line emission in the aligned component, suggesting that the
optical continuum light dominates the two knots (O'Dea et al. 1999).

4. 2005A&A...435..839T
4.2 Previously identified inverted-spectrum sources
B1828+487: this is a CSS quasar with a turnover frequency of <20 MHz
(e.g. Spencer et al. 1989) at z = 0.692 that has detailed
correspondence between the radio and the optical images of the nucleus
and the hotspots (de Vries et al. 1999). It is one of the brightest
sources in the 3C catalog, where it is called 3C 380. It has been
discussed (e.g. Wilkinson et al. 1991) whether this source is
intrinsically small (jets of 2.6 kpc Liu & Zhang 2002) or completely
surrounded by a halo of 60 kpc in diameter (Wilkinson et al. 1991) and
a representative of the CSS class or is it a Fanaroff-Riley type II
galaxy viewed from end-on. The superluminal motion found by Wilkinson
et al. (1991) support the latter but the comparatively weak and
non-variable core is inconsistent with it. The optical polarization of
this source is low: only 0.89% (Wills et al. 1992).
Again our data (Fig. 5) lacks the low frequency end of the spectrum so
the possible turnover at low MHz-frequencies cannot be verified. There
are only minor variations at high frequencies, in good agreement with
the properties observed by Wilkinson et al. (1991).

5. 2002AJ....124..662Z
Re:TXS 1828+487
1828+487: This is a powerful FR II compact steep-spectrum radio
source surrounded by a halo of 14" x 9" in size (van Breugel et al.
1992). The superluminal motions in this source are described by
Polatidis & Wilkinson (1998). Taylor (1998) reported high rotation
measures at parsec scales. The source has a prominent jet extending
toward the northwest, which is also visible in our image. Components
can be identified at distances of ~4 and ~10 mas from the core in
P.A. ~ 30^deg^. Similar structures are visible in the 5 GHz space
VLBI image of Lister et al. (2001).

6. 1999ApJ...526...27D
Re:3C 380
3C 380.-[O II], z = 0.692. This quasar is classified in the "detailed
correspondence" category because of the precise match of the nucleus and
both hot spots in the radio and optical images. The lack of line
emission suggests that the optical emission is pure continuum.
O'Dea et al. (1999a) suggest that the optical hot spots are most likely
due to synchrotron radiation from the same population of electrons that
produces the strong radio hot spots.

7. 1998MNRAS.299..467L
Re:3C 380
3C 380. The multifrequency polarization properties of this source have
been studied by Flatters (1987) and Wilkinson et al. (1991) with the VLA
and MERLIN. The unresolved southernmost component in our map contains
the core and the VLBI jet, which has 6 per cent polarized emission, with
position angles perpendicular to the jet. In the component B, m is
16 per cent and the position angles are parallel to the original jet
direction. We have partially resolved the region where the jet appears
to be disrupted, changing direction towards the east, possibly creating
the arc seen by Flatters.

8. 1998ApJ...506..637T
Re:3C 380
This quasar (z = 0.692, 1 mas = 7.9 pc) is among the most luminous
sources in the 3C catalog. Although traditionally classified as a
Compact Steep Spectrum (CSS) source, it is more likely to be an FR II
source viewed at a small angle to the line of sight (Wilkinson et al.
1991). The mas-scale structure and evolution have been studied by
Polatidis & Wilkinson (1998) at frequencies ranging from 1.6 to 22 GHz.
Polatidis & Wilkinson find dramatic changes in flux density and
structure at the bright component (A) 8.9 mas northwest of the core at
epoch 1997.07 and an average proper motion of 0.2 mas yr^-1^.
The only polarimetric VLBI observation in the literature is reported
by Cawthorne et al. (1993) for epoch 1984.78 at 5 GHz. Cawthorne et al.
find the core component to be less than 1% polarized and component A to
be ~4% polarized. Farther from the core in the broad, extended jet, they
find the polarization to increase to 77%, which is near the theoretical
maximum permitted from incoherent synchrotron emission. Cawthorne et al.
note that the electric field vectors in this extended jet are also
remarkable in their uniformity: the projected magnetic field lies within
4^deg^ of the local jet direction after correction using the integrated
RM of 130 rad m^-2^ (Wilkinson et al. 1991). A comparison between the
VLBI observations of Cawthorne et al. and nearly contemporaneous VLA
observations by Rusk (1988) suggest that the intermediate scale
structure is ~8% polarized and has a projected magnetic field that
continues to run parallel to the jet.
The core is found to be only weakly polarized at all frequencies (see
Table 3). At 15 GHz in the inner jet (components C1 and C2), the
polarization increases to 2.2% and 5.8%, respectively, and reaches a
maximum of 13% at component A ( Fig. 7a). The electric-vector position
angle changes abruptly between the core, C1, and C2. In the core, the
RMs are not well fitted by a {lambda}^2^ law. Good fits to a {lambda}^2^
law are obtained in component C1 with observed values of -880 +/- rad
m^-2^. In component C2 the RMs fall abruptly to -30 +/- 70 rad m^-2^
and remain low throughout the extended jet (see Fig. 2 and Table 3). The
RM-corrected magnetic field orientation is shown in Figure 3.
Given the low RMs found at component C2 and beyond, I have combined
the data from all four frequencies between 4.6 and 5.1 GHz to produce
the image shown in Figure 8. In addition to increasing the sensitivity
through additional data, this has the added advantage of improving the
UV coverage and hence the image fidelity. I find component A to be 12%
polarized but do not find the polarization to increase as dramatically
in the diffuse extended jet as reported by Cawthorne et al. Rather, the
polarization ranges from 5%-35% with the maximum values occurring along
the edge of the source. At the edges the high fractional polarization
may result in part from errors in the total intensity image.

9. 1997ApJS..110..191d
Re:3C 380
3C 380 (quasar, z = 0.692, m_F702W_ = 16.86).-This source also has a very
detailed one-to-one correspondence between the optical and radio
emission. Both optical hot spots to the north-west are closely matched by
peaks in the radio emission, so these optical hot spots probably
originate from synchrotron radiation. Because of the close correlation,
we assume an alignment angle of 0^deg^. Superluminal motion in this
source was found by Wilkinson (1990), implying a viewing angle nearly
perpendicular to the plane of the sky. The intrinsic source size is
therefore significantly larger than the 20 kpc CSS limit.

10. 1995A&AS..112..235A
Re:3C 380
3C 380 (1828+48)
This source has been discussed in detail by Wilkinson et al. (1990). We
confirm the very asymmetric depolarization between 1.3 and 5 GHz.

11. 1995A&AS..110..213R
Re:[HB89] 1828+487
1828+487 (3C 380): The 408 MHz map was made from data supplied by P.
Wilkinson and the 1666 MHz maps published in Wilkinson et al. (1984). The
5 GHz map was made from 2 mins of data. The angular size listed in Table
2 refers to the separation of the brightest points in the extended
structure. The low brightness structure has an angular size of ~16

12. 1994ApJS...93....1A
Re:3C 380
Q1828+4842 (3C 380, z_em_ = 0.695)
Boisse et al. (1992) studied this object in the range 3139 -
3946A and found no lines. Spectrum #1 for this object suffers
from the flattening problem in the July 1988 spectra. In our spectra
we find Galactic Na I and tentative CaII.

13. 1994ApJS...91..491G
Re:3C 380
1828+487 (3C 380) - Our 4m and 2.1m observations agree well. We were
unable to fully correct for the effects of strong sky emission on the red
wing of H{beta} and for atmospheric absorption in the core of the H{beta}

14. 1994A&AS..105...91B
Re:3C 380
1828+487 (3C 380, Fig. 49) Radio maps at subarcsecond resolution of this
complex CSS quasar can be found in Pearson et al. (1985; 8.4 GHz VLA A
array map), Akujor et al. (1991; 5 GHz MERLIN map), and in van Breugel et
al. (1992; 1.4 GHz VLA map). The image given in Pearson et al. (1985)
displays more complex fine scale structure than our 15 GHz image.

15. 1992A&A...256...56v
Re:3C 380
3C 380 (Fig. 6): This source is surrounded by a halo of ~14" X 9"
accounting for 50% of total flux density at 1.5 GHz. For a detailed
discussion of the source structure see Wilkinson et al. (1990). and
Wilkinson et al. (1991).

16. 1988ApJ...328..114P
Re:3C 380
1828+487 (3C 380).-The large-scale structure of 3C 380 has been mapped
a number of times. VLA observations at 5 GHz by Pearson, Perley, and
Readhead (1985) show a complex structure extending over 9". This
structure is similar to that mapped at 1.7 GHz using MERLIN (Wilkinson
et al. 1984a, b; Flatters 1987). Four components can be distinguished in
these maps: a compact flat-spectrum core, a short "jet " extending to
the northwest, a bright ridge of emission 3" east of the core, and a
diffuse halo in which these features are embedded.
The compact component has been studied in several VLBI observations
(Readhead and Wilkinson 1980; Wilkinson et al. 1984a), and was observed
in the course of this survey. These observations show a compact,
flat-spectrum core with a steeper elongated component, generally
identified as a "jet," extended 15 mas in P.A. -57deg, close to the
position angle of the VLA and MERLIN maps (- 45deg).
The projected radius of the halo is 20h^-1^ kpc; thus even modest
deprojection by a factor of 2 would probably p1ace these regions outside
the parent galaxy. The spectrum of 3C 380 is steep between 20 MHz and 5
GHz, but flattens above 5 GHz owing to the flat-spectrum core component,
which dominates the spectrum at frequencies above 10 GHz.
It is possible that 3C 380 may be a classical triple source seen
end-on. There are 20 steep-spectrum double or triple sources in our
sample, so that the probability of having one of these objects aligned
within 5deg of the line of sight is about 10%, which is not too unlikely
for consideration. The size and power of the halo are typical of the
outer lobes of powerful triple sources, and the dominance of the
flat-spectrum core could be due to relativistic boosting of a weak core
component. An alternative possibility, advocated by Wilkinson et al.
(1984a), is that the morphology of 3C 380 is due to interaction with
the interstellar medium. Observations of the broad and narrow optical
emission lines may help to discriminate between these two possibilities.
Where necessary, we have assumed H_0_ = 100h km s^-1^ Mpc^-1^ and
q_0_ = 0.5 to convert angles to projected distances.

17. 1965AJ.....70..384W
Re:3C 380
Of three objects visible within the search area two are red with m_pg_'s~21. The
third is starlike, blue, m_pg_ ~17.0 and is located 15" E of the radio position.

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