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Notes for object ARK 120

13 note(s) found in NED.


1. 2008ApJ...673...96A
Re:1ES 0513-002
QSO B0513-002 is a Seyfert 1 galaxy. The BAT and ASCA spectra can be fit by an
absorbed power-law model and a blackbody component. The required absorption is
in agreement with the Galactic one. The photon index and the plasma temperature
are, respectively, 1.83^+0.02^_-0.016_ and 0.27^+0.02^_-0.02_ keV. We also
detect an iron line whose equivalent width is 90.8^+66.2^_-76.7_eV.

2. 2004MNRAS.350.1049G
Re:ARK 120
9.9 Akn 120 Akn 120 has been monitored in the visible region at SAAO by
Winkler et al. (1992), Winkler (1997) and in a service observing
programme at SAAO under the control of Dr D. Kilkenny.
It has also been observed extensively by Doroshenko & Lyuty (1999),
who found that the U - B colour of its variable component did not remain
constant during two episodes of fading.
A delay of about 315 d was found between U and L, but between J and L
only ~60 d was found. Clavel et al. (1989) found that the delay between
U and the near-IR wavelengths tended to be increase with wavelength in
F9. Uneven sampling could also play a part in the seeming discrepancy.

3. 2003ApJS..146....1W
Re:MRK 1095
Mrk 1095 (Akn 120).-This sight line shows narrow Galactic O VI, similar
to that seen in the neighboring directions toward Mrk 618 and HE 0450-2958.
The feature at 1030.578 {angstrom (-390 km s^-1^ on the O VI velocity
scale) is obvious and strong in the LiF2B segments of both observations,
but may be absent in the LiF1A segments. The measured b-value is very
low (14 km s^-1^). This casts doubt on its reality, even though in the
combined spectrum it nominally is a 3.4 {sigma} detection. If this
feature were intergalactic Ly{beta} at = 1420 km s^-1^, the
corresponding Ly{alpha} line would have an equivalent width of
140 m{angstrom}. Unfortunately, it is not possible to check this, as
this line would be at {lambda} = 1221.420 {angstrom}, whereas the GHRS spectrum
of Mrk 1095 only extends to 1222.4 {angstrom} (see Penton et al. 2000,
who use the name Akn 120). The FOS spectrum may show a feature at the
right wavelength but is rather noisy. However, the absence of a known
galaxy group with similar velocities argues against an interpretation
as Ly{beta}. We list it as "unidentified."

4. 2002AJ....124..675C
Re:UGC 03271
Unsually warm FIR source: alpha(25,60) = 0.51. Seyfert 1.

5. 2001ApJS..136...61S
Re:MRK 1095
5.14. Mrk 1095 (=UGC 3271 = Ark 120)
The nucleus of Mrk 1095 exhibits a typical Seyfert 1 spectrum
(Rafanelli & Schulz 1991) whose optical continuum and emission line show
variability over times scales of years (Peterson et al. 1998). A dominant
unresolved nucleus is reported in HST observations by Nelson et al. (1996).
The 3D data show very broad Br{gamma} emission centered on the nucleus and
a very red spectrum. The latter can be interpreted as hot dust emission
diluting the stellar continuum. This is in qualitative agreement with
Oliva et al. (1999b), who use a technique of fitting stellar template
spectra to restricted portions of the H- and K-band spectra and report
stellar contributions of 50% and 25% at 1.62 and 2.29 microns,
respectively.

6. 1998ApJ...501...82P
Re:ARK 120
The galaxy Akn 120 is of special interest to us, as it provided the original
evidence that the BLR is more compact than was thought at the beginning of the
last decade (Peterson et al. 1985b). Through the mid-1980s, we monitored Akn 120
regularly with the OSU IDS (see Peterson, Korista, & Wagner 1989, and references
therein). Several problems prevented obtaining an accurate measurement of the
lag:
1. The temporal sampling, originally selected on the assumption that the BLR was
a light year or so in radius, was too poor to resolve the line response.
2. The typical uncertainties in the IDS measurements were ~8%; short timescale,
low-amplitude variations simply could not be detected.
3. The narrow [O III] {lambda}{lambda}4959, 5007 lines are unusually weak in
Akn 120 (see Figs. 1, 2, and 3), and flux calibration based on
[O III] {lambda}5007 is less reliable than it is normally. This leads to
systematic "correlated errors" in the continuum and emission-line fluxes at zero
lag; i.e., any error in the [O III] {lambda}5007 calibration introduces a
systematic error that drives the continuum and line fluxes in the same
direction, thus artificially enhancing the cross-correlation at t = 0.
The large flux uncertainties presented the biggest problem with the earlier IDS
data, since simulations suggested that the systematic correlated errors would
not matter if the total error level could be decreased by a factor of 2 or more
(Gaskell & Peterson 1987). In fact, replacement of the IDS spectrograph with the
CCD spectrograph has decreased the uncertainties by a factor of 4.
The combined IDS and CCD continuum and H{beta} light curves of Akn 120 are shown
in Figure 15. The dramatic improvement in the signal-to-noise ratio of the light
curves between the two instruments is readily apparent. It might seem
disturbing that the amplitude of variability seems to have decreased with the
advent of the improved instrument, but this type of behavior is seen in more
homogeneous data as well. Mrk 509 (Fig. 9) shows a similar episode of violent
variability followed by lower amplitude variations. Since it was these dramatic
variations in Akn 120 that led us directly to programs such as reported here, we
do not regard the difference between the variations seen in the early 1980s and
those in the early 1990s as especially suspicious.
Figure 16 shows the result of cross-correlating the IDS continuum and H{beta}
light curves (also shown in Fig. 17 of Peterson et al. 1989). The centroid of
the ICCF shown in Figure 16 is {tau}_cent_=8.7_-10.2_^+9.9^ days, which is
certainly erroneous because the systematic errors have not been included in the
FR/RSS simulations. The sharp peak at zero lag demonstrates the strong influence
of correlated errors in this source. Peterson, Korista, & Wagner point out that
the asymmetric part of this function peaks at 51 +/- 12 days, which is generally
consistent with the results reported in Table 6, based on the higher quality CCD
data. The asymmetric peak around zero lag is also found using the DCF method,
also shown in Figure 16. This is contrary to what is stated by Edelson & Krolik
(1988) because the version of the DCF code used by Edelson & Krolik contained an
error in how the data were weighted (see White & Peterson 1994, footnote 2). Our
version of the DCF does not weight the data at all. Figure 16 should be compared
directly with Figure 5b of Edelson & Krolik.
The cross-correlation lags that we obtain for Akn 120 are also generally
consistent with the estimates of Gaskell & Peterson (1987; {tau} = 14+/-21 days,
based on a Monte Carlo model that included the effects of correlated errors) and
of Peterson & Gaskell (1991; {tau} = 39+/-14 days, based on combined UV/optical
data obtained during the largest outburst).

7. 1998AJ....116.2682C
Re:IRAS 05136-0012
UGC 03271, Mrk 1095. Seyfert 1. Optical position from Kojoian et al.
(1981).

8. 1998A&AS..129...87B
Re:IRAS F05136-0012
IRAS F05136-0012:
Relatively large offset of about 50 arcsec between the X-ray centroid and the
infrared position. A PSPC pointed observation on F05136-0012 indicates that the
X-ray centroid position and the optical position coincide. Therefore the offset
is probably due to an unusually large aspect error of the survey data.

9. 1998A&AS..129...87B
Re:IRAS F05136-0012
Relatively large offset of about 50 arcsec between the X-ray centroid and the
infrared position. A PSPC pointed observation on F05136-0012 indicates that
the X-ray centroid position and the optical position coincide. Therefore the
offset is probably due to an unusually large aspect error of the survey data.

10. 1996ApJS..102..309M
Re:ARK 120
Both the [O III] and H{alpha} emission in this Seyfert 1 galaxy have "halo"
morphologies. None of the observed emission fits our criterion for high
excitation gas.

11. 1996AJ....111.1431B
Re:1ES 0513-002
0513-002: No clear evidence for an HFE appears in the new measurements.

12. 1995ApJS...99..461N
Re:MRK 1095
Figure 2 shows the two prominent sources comprising Mrk 1095. The eastern
source, a, is the more luminous of the two. Figure 11 shows source a to
have no emission lines but a strong continuum about 4 times higher than
the continuum for source b. The spectrum for b is that of a Seyfert 2
type object. Inspection of Figure 2 shows wisps of material,
predominantly around source b (especially to the northwest), but with a
definite ``arm" of material from the area of source a arcing up and to
the west. The ``arm" measures nearly a full arcminute in length. The
heliocentric velocity as measured from the H{alpha} line of source b is
9,800 (+/-600) km s^-1^ making Mrk 1095 131 Mpc distant. The linear
projected separation of the two sources is therefore 24 kpc, with the
northwest arm measuring 36 kpc in length. If these two objects are really
physically related to one another, as opposed to being superimposed on
the sky, the structures linking the two are on the order of the size of
the Milky Way. Examination of the continuum subtracted H{alpha} image
shows almost no emission whatsoever with the exception of the faint
region to the northwest of source b seen in Figure 2.
Absorption lines dominate the spectrum of source a, indicating it is
either a normal (non-active) galactic nucleus similar to that of an Sa or
Sb type spiral (Kennicutt 1992) or a foreground star. MacKenty (1990)
using the University of Hawaii's 2.24 meter telescope at Mauna Kea
Observatory classifies a as a foreground star and attributes the faint
halo of emission as due to reflections in the optics. Inspection of
Mackenty's image shows the same structures as observed with the 5-meter
but with the addition of an off-center halo around the a source which is
assumed to be the reported reflection.

13. 1975ByuO...47....1A
Re:ARK 120
Object with jets or faint spiral arms.
Neutral color.


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