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Notes for object NGC 6814

22 note(s) found in NED.


1. 2009ApJ...705..199B
Re:NGC 6814
The lag structure for NGC 6814 as a function of velocity is shown in Figure 16,
which again demonstrates that the lag time measured for each velocity bin is
consistent with a constant value, although there is a slight preference for
longer lag times in the line core than the wings. This behavior is most likely
consistent with gas in circular orbits.

2. 2009A&A...502..457G
Re:NGC 6814
A.1.10 NGC 6814 This source is an unabsorbed Sy 1.5, with log N_H_ < 20.7
(Reynolds 1997). It is known to be highly variable, even after accounting for a
neighboring CV that contaminated early observations (e.g. see the results of
long-term RXTE monitoring described by Mukai et al. 2003). Using the PL model
with {GAMMA} = 2.48 from Beckmann et al. (2006) and extrapolating from their
INTEGRAL 20-100 fluxes to below 10 keV suggests that JEM-X should have detected
the source, which it did not. Instead, some spectral curvature probably needs to
be invoked. Including a simple PEXRAV (Magdziarz & Zdziarski 1995)
parametrization with {GAMMA} = 1.6, R = 1 and E_cut_ = 150 keV agrees with 20-40
keV and 40-100 keV fluxes of Bird et al. (2007) and with the mean published RXTE
observations mentioned above, and also matches the <10 keV photon-index found
from ASCA analysis of data in the Tartarus database. This implies a mean L_2-10_
= 1.33 x 10^42^ erg s^-1^. A large variation of 0.4 in dex accounts for the
source variability.

3. 2007AJ....134..648M
Re:NGC 6814
NGC 6814 (Figs. 7.13, 9.13, 20.13): In this image there is not much visible
apart from the plain PSF of the nucleus and some faint structure of the outer
face-on spiral.

4. 2004MNRAS.350.1087S
Re:NGC 6814
NGC 6814: this SABbc galaxy presents a quite compact bulge. This fact,
along with the relatively poor seeing (~2.3 arcsec full width at half
maximum (FWHM)) prevented us from obtaining V-band morphological
parameters. Marquez et al. (1999) observed this galaxy in the J- and
K'-bands, finding bar parameters (PA, {epsilon}) very similar to ours
(see Paper I). Nevertheless, the bulge and disc morphological parameters
derived in the NIR are quite different from our optical parameters
(though comparable): the bulge and disc equivalent radii lie between 9.2
arcsec and 62 arcsec in the J-band and 5.5 arcsec and 40 arcsec in the
K'-band, while our I-band bulge and disc equivalent radius are equal to
2.9 arcsec and 33.8 arcsec, respectively.

5. 2004MNRAS.350.1049G
Re:NGC 6814
9.25 NGC 6814 This is a Seyfert with nearly 'ordinary' colours much of
the time. Oknyanskij & Horne (2001) report an upper limit for the delay
between U and K of 15 d, based on work by B. O. Nelson. The present data
give ~35 d.

6. 2003ApJS..146..353M
Re:NGC 6814
NGC 6814 (GD)
The grand-design nuclear spiral is the most obvious feature in the
circumnuclear region, although there are several additional dust lanes
at larger radii. This is unusual as most of the grand-design spirals
are wider and higher contrast at larger radii and become fragmented
closer to the nucleus.

7. 2002A&A...389...68G
Re:NGC 6814
NGC 6814: this is a nearly face-on galaxy and as a result
the values of the angles are not well constrained. We have
two catalogs of different richness. As the PA can not be
well constrained using our methods, we have decided to
adopt the values from the kinematics of Listz & Dickey (1995)
which are in fair agreement with the values obtained by our
methods for the less rich catalog from Evans et al. (1996).
Note that the richer catalog of Knapen et al. (1993) has a
well delineated strong northern arm which can bias our
results.

8. 1999ApJ...516...97N
Re:NGC 6814
NGC 6814: RC3 does not list a major axis P.A. for this object. ESGC
lists a diameter of 4.47' x 4.47' and Buta (1988, private communication
to the Lyon-Meudon Extragalactic Database; see e.g., Paturel et al.
1997, hereafter LEDA) finds a diameter of 3.02' x 2.88'. Liszt & Dickey
(1995) have mapped the H I emission in this galaxy out to a diameter of
about 6'. They find a large kinematic warp in the outer galaxy disk: the
kinematic major axis decreases monotonically from 200^deg^ at distance
3 kpc from the center to 165^deg^ at distance 21 kpc from the center,
leading them to adopt a major axis P.A._H I_ = 176^deg^. They also
suggest that the galaxy is much more nearly face-on than i = 22 ^deg^,
and we therefore label its inclination as i = 0 ^deg^ (see section 2.4).

9. 1999A&AS..140....1M
Re:NGC 6814
This galaxy shows a beautiful spiral structure on the K' image, with
spiral arms emerging from a thick bar (Fig. 15a). Our image appears to
be quite similar to that of Mulchaey et al. (1997).
The spiral structure is seen in the sharp-divided image, where the bar
is traced as a faint elongation (Fig. 15b). The spiral structure is
clearly observed in the difference image (Fig. 15c).
Except for the very nucleus, the J/K' image remains constant throughout
the galaxy, excepting the innermost 2 arcsec, which are redder
(Figs. 15d and 15h).
The bar parameters from (Fig. 15e) are in agreement with Mulchaey
et al. (1997). Note the strong and sudden change of PA at the radius
where the spiral arms begin. However the bulge + disk fit is very good
(Figs. 15f and 15g). The NICMOS HST image is saturated in the nucleus,
so it cannot be used to gather information on the presence of inner
structures. The bar is seen as a thick elongated 10 arcsec structure
along the NS direction in Fig. 32.

10. 1998ApJS..114...73G
Re:NGC 6814
Section A15. NGC 6814
This Seyfert 1.2 galaxy was first detected in X-rays in the early 1990s,
NGC 6814 had its 15 months of fame because of the apparent detection of a
periodicity in its X-ray light curve (Mittaz & Branduardi-Raymont 1989; Done
et al. 1992) which spawned a frenzy of theoretical activity. However,
subsequent observations by the ROSAT PSPC revealed the periodicity to be the
result of strong contamination by a Galactic source within the field of view
of previous instruments (Madejski et al. 1993). It now appears that the X-ray
emission from this Seyfert 1.2 galaxy is relatively weak. ASCA observed
NGC 6814 on three occasions prior to 1994 May, but only one data set
[NGC 6814(1)] met the criteria for inclusion in our sample (Paper I). The
count rate for this observation, performed in 1993 May, is a factor of 10
lower than any of the other sources in our sample. Given the signal-to-noise
ratio, it is perhaps not surprising that we find the data set to be
consistent with a simple power law ({GAMMA} ~ 1.7) absorbed by N^gal^_H,0_.
R97 also found a lack of evidence for O VII and O VIII absorption edges in
their analysis of this data set.

11. 1998AJ....116.2682C
Re:IRAS 19399-1026
NGC 6814. Seyfert 1. Optical position from Clements (1981).
High-resolution VLA maps of the nucleus at 1.49 and 4.86 GHz in Vila
et al. (1990).

12. 1997ApJS..110..299M
Re:NGC 6814
Bar is visible in both the ellipse fits and the K_S_image. Unbarred in the
RSA.

13. 1997ApJS..108..155G
Re:NGC 6814
The classification of this S1 nucleus has changed from S1 to S2 several
times; it is in an Sbc host galaxy. The nuclear emission is compact, and
the disk shows many H II regions located in the spiral arms. The nucleus
accounts for only 6% of the total H{alpha} emission. Deeper images of the
host galaxy have been presented by Knapen et al. (1993).

14. 1996ApJS..105...93E
Re:NGC 6814
4.14. NGC 6814
The nuclear variability of NGC 6814 has been investigated extensively. Optical
photometry and spectrophotometry (e.g., Morris & Ward 1988; Sekiguchi & Menzies
1990; Winkler et al. 1992; Winkler 1992) reveal that the broad nuclear H{beta}
flux can vary by factors of 2-4 over a period of a few months to a few years,
with smaller variations and continuum variability occurring on shorter
timescales. Figure 1 reveals numerous giant extragalactic H II regions tracing
both the inner and outer spiral arms. The inner spiral arnis are particularly
congested. An H{alpha} image of the galaxy was obtained by Knapen et al.
(1993), who studied the statistical properties of the H II region population
from measurements of over 700 H II regions. Additional H{alpha} + [N II]
{lambda}{lambda}6548,6583 and [O III] {lambda}5007 images have been published
by Pogge (1989a). Like NGC 6300, this is a low galactic latitude object with
some field contamination from foreground stars.

15. 1996ApJS..103...81C
Re:NGC 6814
NGC 6814.--Seyfert 1. VLA A-configuration map at 1.49 GHz and B-configuration
map at 4.86 GHz of the radio core in Vila et al. (1990).

16. 1996ApJ...463..498S
Re:NGC 6814
A12. NGC 6814
Pogge (1989) found that the nuclear [O III] emission of this galaxy is
unresolved when observed from the ground. This galaxy has an unresolved core
and some extended emission along PA 150^deg^. The total extent of the emission
is ~1" (106 pc). There is no emission related to the western radio extension
found by Ulvestad & Wilson (1984a), but the overall distribution of the
[O III] emission seems to follow that of the radio emission.

17. 1994CAG1..B...0000S
Re:NGC 6814
Hubble Atlas, p. 20
Sbc(rs)I-II
PH-236-B
Sep 11/12, 1950
103aO + GG11
30 min
The spiral pattern in NGC 6814 has features
of both grand design and multiple-armed
(MAS) types. However, the arms are quite well
defined as separate entities unlike the arms in
pure MAS galaxies, such as NGC 2841 (panels
142, S4, S12). Here, the main arms can each be
traced for about half a revolution before they
branch and become multiple.
The redshift is v_o = 1643 km/s.

18. 1976RC2...C...0000d
Re:NGC 6814
Type 1 Seyfert nucleus.
B(nucleus) = 15.65.
B_T (excludinmg nucleus) = 12.10.
Photometry (UBV):
A.J., 73, 858, 1968.
Publ. Dept. A. Univ. Texas, II, 2, No. 7, 1968.
P.A.S.P., 83, 392, 1972.
Atti. Conv. Sci. Osserv. Cima Ekar, Padova-Asiago, 101, 1973
= Cont. Asiago No. 300bis.
Photometry (I.R. 1-10 microns):
Ap. J. (Letters), 159, L165, 1970.
Ap. J. (Letters), 176, L95, 1972.
M.N.R.A.S., 169, 357, 1974.
Spectrum:
Ap. J. (Letters), 165, L61, 1971.
Spectrophotometry:
M.N.R.A.S., 168, 109, 1974.
HI 21cm:
Source R2 (Astr. Ap., 6, 456, 1970), quality D, rejected.
Radio Observations:
Australian J. Phys., 19, 565, 1966.

19. 1968MCG4..C...0000V
Re:MCG -02-50-001
Seyfert galaxy (Ap.J., 97, 195)
Type:
vdB - Sb+ I
Sand - Sb
Morg - fgS1
deV - SAB(rs)bc
Photo: Sandage - completely agrees with our description.
Redshift = +1,590 km/sec
F0e
Cp' = 0.89.

20. 1964RC1...C...0000d
Re:NGC 6814
Very small, very bright nucleus in a weak diffuse bar. Several knotty arms
form pseudo (r): 0.75 arcmin x 0.75 arcmin. Weak out parts.
Heidelberg Veroff. Vol. 9, 1926 dimensions are for the bright party only.

21. 1961Hubbl.B...0000S
Re:NGC 6814
Sb
PH-236-B
Sept.11/12,1950
103aO + GG1
30 min
Enlarged 5.0X
Notice the tightly wound multiple arms of this galaxy.
They are thicker than those of NGC 2841, and the nuclear
region is smaller. The arms are highly branched. Each of
the arms is of almost uniform surface brightness for about
one complete revolution, at which point there is a sharp
break in the brightness. Fainter extensions of the arm
system can be traced on the outside of the brighter arms.
The same phenomenon occurs in many galaxies such as
NGC 6384 (left) and NGC 3147 (right).

22. 1918PLicO..13....9C
Re:NGC 6814
Faint, nearly round spiral 2' in diameter. Whorls rather open; stellar nucleus.
3 s.n.


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