NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-24 T05:20:20 PDT
Help | Comment | NED Home

Notes for object AP Lib

16 note(s) found in NED.


1. 2005A&A...442...97A
Re:AP Lib
1514-241 (AP Lib): this is one of the objects which defined the blazar class; it
has presented values of optical polarization between 2-7% (Angel & Stockman
1980). Mead et al. (1990) reported similar values. We followed AP Lib on
different occasions, always with variable results; however, the average degree
of polarization was quite low. During the last night in April 2004 the position
angle rotated in an anti-clockwise direction from 180.3^deg^ to 170.9^deg^ with
a speed of 10.5^deg^/h^1^.

2. 2004MNRAS.347..771W
Re:PKS 1514-24
3.4.14 1514-24 (Ap Lib) This is a BL Lac object, classified on the basis
of its spectrum and light distribution (e.g. see Disney, Peterson &
Rodgers 1974). It is not possible to gain an adequate fit to the
continuum with either an old elliptical galaxy component or a young
stellar component alone, or a combination of the two. Instead a
power-law component is clearly required and is the dominant
component. We get reasonable fits ({chi}^2^ ~0.6) with a 0.05-15 Gyr
component combined with a power-law component, with little difference
between them. The [O III] was detected and from this we derived a
redshift of z = 0.0480.

3. 2002AJ....124..662Z
Re:IERS B1514-241
1514-241: This nearby N-type galaxy displays high
variability in the optical, reaching rates of
0.06 +/- 0.01 mag hr^-1^ (Carini et al. 1991; Bond 1971). The
HST images published by Scarpa et al. (2000) show a bright point
surrounded by a large, round elliptical host. It has a
parsec-scale straight radio jet extending at least 20 to the east
of the core at P.A. = 88^deg^ (Morganti, Killeen, & Tadhunter 1993).
Lister, Marscher, & Gear (1998) published 43 GHz polarimetric
images of this object, showing a jet pointing toward P.A. = -171^deg^,
within 1 mas of the core, then turning to P.A. = 157^deg^. The
RRFID images show a jet toward the southeast. Our image shows
structure toward the southeast out to 5 mas.

4. 1999ApJS..121..131F
Re:AP LIBRAE
This variable ({DELTA}m=3.0mag; Branly et al. 1996) object is located
at the center of an elliptical galaxy with an emission-line redshift of
z=0.049 (Disney, Peterson, & Rodgers 1974), polarizations of
P_3.7 cm_ =4.4% (Wardle 1978), P_IR_ =2%-7.4%, and P_opt_ =7% (Impey
et al. 1982). The infrared data show a correlation between (J-K) and
(H-K): (J-K)=0.18(H-K)+0.84 with r=0.928 and p=4.5x10^-5^. For the color
index and the magnitude, there is an indication of (J-K) increasing with
H, but this is far from certain (see Fig. 17).

5. 1999A&AS..139..601C
Re:[HB89] 1514-241
1514-241: Antonucci & Ulvestad (1985) report a component 21" away from
the core. Our A+B array image at 1.36 GHz shows a jet emerging along the
SE direction and bending towards NE after a dozen of arcseconds, for a
total extent ~ 55" (Fig. 21), also visible in the 4.88 GHz image
(Fig. 22). The image from the D array (Fig. 23) was obtained from the
NVSS survey (Condon et al. 1998), and clearly shows a diffuse emission
on the arcmin scale on the same side of the jet. The flux density of
this component was added to the estimate from our A+B array image.

6. 1998ApJ...504..702L
Re:AP Librae
1514-241 (AP Librae)
AP Lib is a low-redshift (z = 0.0486) BL Lac object with rapidly
variable optical flux (night-to-night; Carini et al. 1991) and optical
polarization as high as 8.0% (Stickel, Meisenheimer, & Kuhr 1994).
Tornikoski et al. (1993) measured a flat radio spectrum out to ~40 GHz,
followed by an {alpha} ~ -0.3 falloff toward the infrared/optical
region. No gamma rays have been detected from this BL Lac object by
either EGRET or the Whipple telescope (Weekes et al. 1996). At arcsecond
scales, AP Lib displays a straight radio jet extending at least 20" to
the east of the core at P.A. ~ 88^deg^ (Morganti, Killeen, & Tadhunter
1993; Antonucci & Ulvestad 1985), and observations by Bondi et al.
(1996) show extended emission out to 57".
Because of the southern declination of AP Lib, the resolution beam of
the VLBA is highly elongated, and unfortunately extended in nearly the
same direction as the parsec-scale jet. As a result, the brightness
distribution in Figure 6 is highly smoothed. Within ~1 mas of the core,
the jet is fairly straight at P.A. ~171^deg^ and contains two components
(C1 and C2; see Table 2). The jet then bends through 14^deg^ to P.A.
~157^deg^. Since no other VLBI maps of this source have been published
in the literature, the apparent velocities of these components cannot be
estimated.
At 43 GHz, we detect polarized emission only at the location of
component C1, where the fractional polarization is approximately 7%. The
electric vector of C1 lies at an oblique angle to the local jet
direction. The upper limit on the core polarization of AP Lib is 0.8%,
which is somewhat lower than the other blazar cores in our sample. If
this is a result of Faraday depolarization caused by dense nuclear gas
(e.g., Cawthorne et al. 1993), it would have to be extremely localized
(within ~0.6 h^-1^ csc{theta} pc of the core), given the fractional
polarization of component C1. On the other hand, it is possible that the
core is merely in a low-polarization state in which it is not creating
any new components. The centimeter-wave EVPA (from the University of
Michigan data) has been relatively stable since 1994.5 (10^deg^ < EVPA <
55^deg^), and no major polarized or total intensity outbursts have
occurred since that time at these wavelengths. Nartallo et al. (1998)
have made one measurement of the EVPA at 273 GHz (epoch 1993.15), and
obtained 4.1^deg^ +/- 8^deg^. These data are consistent with a
transverse B-field during a period of rising 230 GHz flux density
(Tornikoski et al. 1996).

7. 1998AJ....115.1357S
Re:PKS 1514-24
PKS 1514-241 (AP Lib; Fig. 1p).--This source is a classical BL Lac object
(Strittmatter et al. 1972). The redshift is z=0.0486, based upon both absorption
lines and emission lines (Rodgers & Peterson 1977 and references therein). It
has been characterized as an optically violent variable (Carini et al. 1991;
Bozyan et al. 1990; Webb et al. 1988) and a highly polarized quasar (Wills et
al. 1992).
This source shows a core-jet morphology on arcsecond scales in 6 and 20 cm VLA
images (Morganti et al. 1993; Antonucci & Ulvestad 1985; Ulvestad, Johnston, &
Weiler 1983). A component 0.2" from the core at a position angle of 120^deg^ was
reported by Perley (1982).
Our VLBI image of this BL Lac object shows only a single component, 1.2 mas x
0.6 mas in size, with elongation in the north-south direction, and a flux
density of 1.53 Jy. The brightness temperature is 1.1x10^11^ K, which is
consistent with the value of ~1.5x10^11^ K from the 22 GHz survey (Moellenbrock
et al. 1996).

8. 1998A&A...336..479K
Re:PKS 1514-24
PKS 1514-241 = AP Lib is at redshift z = 0.0486 (Disney, Peterson &
Rodgers 1974). Our H-band magnitude agrees reasonably well with
literature photometry (Table 6). The elliptical host galaxy has been
studied extensively in the optical. Baxter et al. (1987) obtained M(V) =
-22.8, Abraham et al. (1991) M(R) = -22.8 and R(e) = 7.5 kpc, and
Stickel et al. (1993) derived M(R) = -23.5 and R(e) = 11.5 kpc. Finally,
we have analysed our unpublished optical images of this BL Lac, obtained
at the ESO 2.2m telescope, and find M(R) = -22.9 and R(e) = 4.3 kpc.
The host galaxy parameters derived by us in the NIR (M(H) = -25.1, R(e) =
3.3 kpc) are in reasonable agreement with those found in the previous
studies.

9. 1994ApJS...93..125F
Re:AP LIBRAE
1514-242.-AP Librae is a classical radio-selected object (Strittmatter et
al. 1972). We observed the source on seven occasions and found flux
variability of up to 1 magnitude. The optical energy distribution clearly
shows the presence of a thermal component from a host galaxy, which
contributes 33% of total flux. The spectral index remained practically
constant; only in the observation of 1987 August, at the minimum detected
flux level, did we observe a spectral index significantly flatter. The
host galaxy absolute magnitude is M_V_ = -21.6 +/-0.2. This value is in
agreement with all the previously reported values (Ulrich 1989; Abraham
et al. 1991; Falomo et al.1993a; Stickel et al. 1993).

10. 1994AJ....107..494P
Re:AP LIBRAE
PKS 1514-241 (AP Lib)
PKS 1514-241 (AP Lib) is a well known, nearby BL Lac object
( z = 0.0486; Disney et al. 1974). These authors noted several galaxies
surrounding the BL Lac, in particular a lenticular galaxy 1 arcmin to the
northeast which has the same radius as the extended halo of the BL Lac
host galaxy. This latter was found to have an absolute magnitude
M_v_~21.4, consistent with that typical for BL Lac hosts (Ulrich 1989).
Stickel et al. (1993) noted that the isphotes of the host galaxy of
AP Lib are asymmetric and elongated towards the large lenticular
[m_R_ = 16.62, 64" northeast at PA = 26^deg^; G1 in the following; see
Fig. 1(d)], suggesting tidal interaction between the two.
We obtained a spectrum of G1 which shows Ca II H and K, the G band,
Mg I {lambda}5175, and Na I {lambda}5892 in absorption giving z = 0.048
[see Fig. 3(h)]. This indicates that the BL Lac host and G1 are really
associated. The projected separation of their centers is 83 kpc.
Due to the low redshift, and hence small field (~0.5 Mpc), of this
object, we are unable to determine reliably and excess of galaxies. We
have calculated the number of galaxies to m_R_ = 20.5 using the average
background and find 39 where 41 are observed. Thus, while we do not
detect a significant excess over the average background, we cannot
exclude the possibility that the intrinsic, local background is lower
than average. Larger scale images are required in this case.

11. 1994A&A...289..673T
Re:[HB89] 1514-241
There are no 22 nor 37 GHz observations available of this Southern
hemisphere source, and the optical data is severely undersampled during
the years 1989-1993 from where there are observations at the higher radio
frequencies. From the available data it is not possible to draw any
conclusions from possible correlations between the different frequencies.
No radio-optical connections of this source have been reported in the
literature.

12. 1993MNRAS.263.1023M
Re:AP Librae
1514-24 (Ap Lib). A well-known BL Lac object observed by Conway &
Stannard (1972) and by Ekers et al. (1989). Our VLA measurement of the
radio core agrees very well with the high-resolution measurement
given in the former paper.

13. 1993MNRAS.263..999T
Re:PKS 1514-24
1514-24 (Ap Lib). BL Lac spectrum: [O III] {lambda}5007 and [O II]
{lambda}3727 lines of small equivalent width. The continuum is blue, but
the Mg I b absorption feature is detected.

14. 1993AJ....106...11F
Re:ESO 514- G 001
1514-241
This is a classical BL Lac object (AP Lib). The presence of a galaxy
component is well apparent in the shape of spectral flux distribution. We
observed this source at three epochs with maximum flux variations of
about 15% in K and up to 50% in V. The decomposition in terms of a power
law plus standard elliptical yields {alpha} ~ 0.95 and P_g_ ~ 0.3. This
results in a host galaxy of M_V_ ~ -21.8.

15. 1993A&AS...98..393S
Re:AP LIBRAE
1514-241
This source has early been recognized as a member of the BL Lac class
(Strittmatter et al. 1972) and was initially associated with the variable
star AP Lib (Bond 1971). Due to its low redshift (z = 0.049), 1514-241 is
well resolved and the direct image shows that the outer isophotes of the
host galaxy are asymmetric and elongated towards a nearby galaxy ~65" to
the northeast. This appearance is reminiscent of tidal interaction
between the two galaxies and suggests that 1514-241 is an up to now
unrecognized interacting system.
In the course of the observations of the 1 Jy BL Lac objects,
spectroscopic observations of 1514-241 or the neighbouring galaxy have as
yet not been obtained, but an optical spectrum of the BL Lac objects
taken during a faint state of the variable central point source was
published by Morris & Ward (1988).

16. 1982ESOU..C...0000L
Re:ESO 151445-2411.4
=ESO 514- G 01
variable radio-source
in cluster


Back to NED Home