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Notes for object WISE J142832.62+424021.0

8 note(s) found in NED.


1. 2008A&A...477..513F
Re:1ES 1426+428
1426+428 has been detected at VHE {gamma}-rays by CAT and HEGRA (Djannati-Atai
et al. 2002; Petry et al. 2000) and has been the target of multiwavelength
campaigns (Horns 2003). Its only reported optical spectrum was published by
Remillard et al. (1989). Their highest S/N spectrum (S/N ~ 10) with the MDM 1.3
m telescope yielded z=0.129 from marginal detections of Mg I and Na I at ~5800
and ~6650 A. Unfortunately, we were not able to achieve a higher S/N spectrum,
nor were we able to observe at a wavelength above 5500 A, thus we could not
confirm this observation; we could only constrain its redshift to z >= 0.106.
The host galaxy of 1426+428 was resolved by Urry et al. (2000) and found to have
m_R_=16.14, leading to a photometric redshift of z = 0.132 +/- 0.030. Our
measurements are consistent with the previous redshift claims.

2. 2004ApJ...613..752G
Re:RBS 1399
1426+428. The comparison of the NVSS total flux density (61 mJy) and the
peak of the A-array image (32 mJy beam^-1^) indicates that some extended
emission is present. Our image confirms the presence of a faint halo
surrounding the central core but does not recover all the flux. Since
previous images in the C array (Laurent-Muehleisen et al. 1993) detected
an intermediate value of 46 mJy, we believe that the difference has to
be ascribed to resolution effects rather than variability. The northwest
extension is oriented at P.A. ~ 50deg and therefore presents a
{DELTA}P.A. = 30deg with respect to the inner structure studied by
Kollgaard et al. (1996). Note that this is a TeV source (Aharonian et
al. 2002; Horan et al. 2002).

3. 2001A&A...371..512C
Re:1ES 1426+428
3.2.6 1ES 1426+428
The spectrum of this object is very well fitted by a single flat power-law
model, with galactic absorption: there is no clear sign of bending in the
shape of the residuals (see Fig. 10). Broken power-law models do not
statistically improve the fit, and moreover give values of {alpha}_1_ and
{alpha}_2_ both flatter than unity [they are also only marginally different
({alpha}_2_-{alpha}_1_ ~ 0.1)]. The data in the PDS band are particularly
important for this source, in order to assess or not the presence of a
steeper component ({alpha} > 1) that would reveal the position of the
synchrotron peak.
Unfortunately, the PDS data are contaminated by another known hard
source, namely the quasar GB 1428+422 (Fabian et al. 1998). This object,
characterized by a very flat spectral index ({alpha} < 0.5), lies at 41'
from 1ES 1426+428, thus inside the PDS f.o.v. but outside the MECS f.o.v..
For a lucky coincidence however, the quasar was observed by BeppoSAX on
4/2/99, four days before our observation. Thanks to the collaboration
between the two proposing groups, we have been able to estimate the
relative inter-contamination. Furthermore, we have also checked in NED and
WGACAT databases for other potentially contaminating sources within 80'
from 1ES 1426+428, selecting hard sources (HR >0.8) and/or with a high
countrate, excluding those already identified as stars, and estimating
their flux in the PDS range under the assumption of a power-law spectrum.
Besides the quasar, the highest contributions came from two sources:
WGA J1426.1+4247 ({alpha} ~ 0.57, ROSAT countrate = 0.011 cts/s) and
CRSS 1429.7+4240 ({alpha} ~ 0.87, ROSAT countrate = 0.015 cts/s). Their
estimated high energy X-ray flux turned out to be roughly two orders of
magnitude lower than 1ES 1426+428 in the PDS band, so we did not consider
them, leaving GB 1428+422 as the only contaminating source.
The PDS data of both blazars were contaminated one by the other. The
strategy to disentangle the two contributions has been the following. First
we fitted only the LECS+MECS data of both sources. Then we extrapolated
these best fit models into the PDS range, for estimating the relative
contaminations. We fitted the combined LECS+MECS+PDS data of one source,
adding in the PDS range the LECS+MECS model of the other source, after
accounting for the instrument off-axis response, and cross-checked the
results for consistency. In Fig. 11 the single components of the models
used in the 1ES 1426+428 fit are shown, together with the total expected
flux in the PDS instrument. Of course, this technique is based on the
assumption that no large changes of flux or spectral index occurred in the
four days separating the two observations, but in any case it gives a
reference point to estimate possible variations. Figure 10 (left panel)
shows the fit including for the PDS model the BeppoSAX spectrum of
GB 1428+422 ({alpha} = 0.42, F_1 keV_ = 0.30 microJy). The PDS points
remain slightly above the flat ({alpha}_X_ = 0.92) power-law that fits the
1ES 1426+428 LECS+MECS data, however the fit is good ({chi}_r_^2^ = 1.06),
with no sign of declining slope up to 100 keV. A broken power-law model
gives even flatter indices above 10 keV ({alpha}_2_ ~ 0.3-0.4), however,
these values are not very plausible, since, even not considering the
GB 1428+426 contribution, the emerging of such a flat component would have
implied a 3{sigma} detection in the PDS also in the 100-200 keV band, not
observed (~8.2 10^-2^ cts/s against the observed 2.2 +/- 2.7 10^-2^ cts/s).

4. 2001A&A...371..512C
Re:1ES 1426+428
Assuming also the possibility of a large flux variation for GB 1428+422
(not unlikely: in 1998, during pointed ROSAT HRI observations, it has
doubled its flux over a timescale of two weeks or less, see Fabian et al.
1999), we also fitted the PDS data letting the GB 1428+422 normalization
free to vary (Fig. 10, right panel). Again, the 1ES 1426+428 spectrum
remains flatter than unity up to 100 keV, even accounting for a GB 1428+422
increase of a factor ~4 in 4 days, from F_1 keV_ = 0.30 microJy to
F_1 keV_ = 1.44 microJy. Given the SED of 1ES 1426+428 (see Fig. 14), this
result quite reliably constrains the synchrotron peak to lie near or above
100 keV.

5. 2001A&A...371..512C
Re:1ES 1426+428
4.2 1ES 1426+428
Besides ROSAT, this source has been previously observed also by HEAO-1,
EXOSAT, ASCA and the BBXRT experiment (details in Sambruna et al. 1994,
1997). In Fig. 13 we report the historical flux levels in the 2-10 keV
band, together with the measured spectral indices in that band. In all the
previous observations, there is no evidence of a flat spectrum above 2 keV,
even in the presence of large flux variations. The BeppoSAX observation is
the first where this source showed a flat spectrum up to 100 keV. In BBXRT
and ASCA data, the full band spectrum is best fitted by a broken power-law:
in this case, the resulting break energy locates the synchrotron peak, for
both observations, between 1 and 2 keV. This source therefore has undergone
a shift in the peak frequency of at least two orders of magnitude. Note
that, as shown by Fig. 13, the BeppoSAX flux in the 2-10 keV band of
1ES 1426+428 is not particularly high: it is the second lowest state
observed, about ~20% higher than the lowest one, observed by ASCA
(2.04 vs. 1.64 10^-11^ ergs cm^-2^ s^-1^, in the 2-10 keV band). This
indicates that the object can be very powerful above 10 keV while remaining
inconspicuous in the soft X-ray band. This is also supported by the XTE
monitoring, which did not show any special activity during the BeppoSAX
observation. The other two "over 100 keV" sources (i.e. Mkn 501 and
1ES 2344+514) showed a markedly different behavior, becoming very active
and strong also below 10 keV when their synchrotron spectrum peaks at high
energies. 1ES 1426+428 has shown that the soft X-ray activity is not always
necessary to be a strong 100 keV synchrotron emitter. At the same time, in
this source, a relatively faint 2-10 keV state does not guarantee a hard
spectrum (see e.g. the ASCA and ROSAT data in Fig. 13): all this is
revealing of a complex relation between the injected power and the location
of the synchrotron peak.

6. 1996ApJ...460..174K
Re:87GB 142634.5+425353
4.3. 1426+429
From VLA observations this z = 0.13 XBL shows some evidence of a diffuse radio
halo around an unresolved core and has relatively weak radio and optical
polarization for a BL Lacertae object (Laurent-Muehleisen et al. 1993;
Jannuzi, Smith, & Elston 1994). No previous VLBI observations have been made.
Our I image of 1426+429 is shown in Figure 3. The source is compact, although
a bulge to the northeast is clearly visible. A model fit to this weak double
structure is given in Table 1. Our integrated polarization measurements
indicated that during our observations the source was unpolarized, and no
polarized flux was detected on milliarcsecond scales.

7. 1995ApJS..100...37G
Re:H 1426+428
1H 1427+42 is an XBL (Maccagni et al. 1989; Remillard et al. 1989;
Burbidge & Hewitt 1992; Giommi et al. 1990; Hewitt & Burbidge 1993). It
was observed with EXOSAT on 1985 January 12. The power-law plus
absorption model fits this spectrum best (Table 3). This blazar is a
steep-spectrum ({GAMMA} = 2.10 +/- 0.07) source with no intrinsic
absorption (Remillard et al. 1989). The radio through X-ray spectrum of
this blazar is shown in Figure 4i, and it can be represented by a single
parabolic spectral component.

8. 1993ApJS...85..265J
Re:H 1426+428
H 1426+428
We confirm this object's classification as a BL Lac object because we have
detected intrinsic and variable polarized emission. However, we did not
observe a value for the percent polarization greater than 3%. The evidence
for variable polarized emission comes from the variation in {theta}. In
Paper II we discuss whether or not a minimum observed polarization (e.g.,
3%) should be required for an object to be classified as a BL Lac object.


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