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Notes for object UGCA 166

12 note(s) found in NED.


1. 2004ApJ...607..309I
Re:MRK 0116
Markarian 116 (1 Zwicky 18).-This sight line pierces high-velocity cloud
Complex A and a marginal detection of N V at v ~ - 150 km s^-1^ might be
associated, but this is rejected as is the entire sight line, because no
low-velocity N V is detected.

2. 2003ApJS..146....1W
Re:MRK 0116
Mrk 116.-The continuum near the O VI {lambda}1031.926 line is somewhat
difficult to determine, as the absorption lies in the shoulder of the
Ly{beta} absorption associated with Mrk 116. The decision on where to
place the continuum was helped by knowing the expected strength of the
H_2_ lines. This justifies placing the continuum fairly high.
The H_2_ J = 4 line contaminates the positive-velocity edge of the thick
disk absorption, but it only increases the systematic error from 21 to
24 m{angstrom}.
This is one of three sight lines projected onto HVC complex A. No
obvious associated high-velocity feature is present in the combined
spectrum.

3. 2001A&A...373...24P
Re:SBS 0930+554
0930+554 complex morphology with propagating SF wave (Izotov 1999, private
communication).

4. 2000ApJ...531..776G
Re:I Zw 018
0930+554 = I Zw 18 = Mrk 116.-Izotov et al. (1997) and Legrand et al.
(1997) detected both the blue and red bumps in this BCD, the most
metal-deficient WR galaxy known. Izotov et al. (1997) also saw
N III {lambda}4512 and Si III {lambda}4565 emission lines. However, they
misidentified the latter line as Mg I {lambda}4571. Possibly,
N II {lambda}5720-40 and {lambda}5928-52 lines are detected, indicating
the presence of WNL stars. In contrast, Legrand et al. (1997) who
observed with a different position angle of the slit found evidence only
for WCE stars.

5. 1999A&AS..136...35S
Re:I Zw 018
I Zw 18 -- This well-known object is the galaxy with the lowest metal
content known. While nebular He II {lambda}4686 was observed
for a long time, only recently the deep spectra of Izotov et al. (1997b)
and Legrand et al. (1997) revealed several broad emission components
(C III {lambda}4650, He II {lambda}4686, C IV {lambda}5808) attributed
to WN and WC stars. The spatial distribution of He II {lambda}4686
emission was studied by Hunter & Thronson (1995) and De Mello et al.
(1998) based on WFPC2 HST observations. Izotov et al. (1997a) indicate
the presence of low intensity broad components of H{alpha} and/or
[O III] {lambda}5007.

6. 1998ApJ...506..222M
Re:I Zw 018
A bubble with radius r = 970 pc and projected expansion velocity v =
34 km s^-1^ was found south-southwest of the northwest H II region. A
kiloparsec-scale loop of H{alpha} emission also extends north-northeast
from it, although the kinematic evidence for expansion is less secure.
Notice how similar the velocity structure in I Zw 18-1 is to that in NGC
1569-11, NGC 1569-10, and even to that in M82-2. The main difference is
that the magnitude of the line splitting is about 5 times larger in M82.
See Martin (1996) for a discussion of the power requirements of these
shells and the associated production of metals.

7. 1998ApJ...506..222M
Re:I Zw 018
One might expect mass loss of catastrophic proportion, since I Zw 18
is one of the least luminous galaxies yet contains a kiloparsec-scale
polar bubble. (Note that only the southern lobe of the bipolar shell
discussed by Martin 1996 was detected kinematically and therefore
cataloged Table 3.) If the H I velocity field actually reflects a
rotating disk in equilibrium; however, the dynamical mass within r = 850
pc is ~5 x 10^8^ M_sun_ (Viallefond, Lequeux, & Comte 1987; van Zee et
al. 1998)-a bit more than NGC 1569! In Figure 9, the projected
expansion speed of the polar shell, 30 km s^-1^, is less than the escape
speed from an r_0_ = 1.4 kpc Burkert halo (dotted line). The deprojected
shell velocity, closer to ~90 km s^-1^ (Martin 1996), may exceed this
escape velocity. The central density must be increased by 9.4 over
Burkert's {rho}0(r0) relation to reach a circular velocity of 50 km
s^-1^ (solid line). Since the dynamical mass estimate greatly exceeds
the mass of this halo model, the argument for escape of the warm ionized
shells is marginal.

8. 1993ApJS...86....5K
Re:I Zw 018
I Zw 18 (UGCA 166, Mrk 116); Irr, BCDG.
This blue compact dwarf galaxy is one of the most metal-poor galaxies
known ([O/H ~ 0.02[O/H]_sun_; Dufour, Garnett, & Shields 1988). I Zw 18
has been described as the prototypical isolated extragalactic H II region
that is most probably undergoing its first burst of star formation
(Searle & Sargent 1970). There are two separate star-forming regions in
this galaxy, surrounded by a 3 kpc envelope of H{alpha} emission (Dufour
& Hester 1990). The UV spectrum of this super-metal-poor compact galaxy
rises to the blue and contains weak low-ionization absorption features
(Dufour et al. 1988).

9. 1985AnTok..202.335T
Re:KUG 0930+554
A pair of high UV-excess compact galaxies. Magnitude listed here is
a total of 15.4 + 17.6 given in the I Zw Catalogue.

10. 1976RC2...C...0000d
Re:MRK 0116
= I Zw 018
Close pair of blue compacts consisting of
A0930+55A and A0930+55B separated by 5.6 arcsec.
Description and Dimensions:
Ap. J. (Letters), 162, L155, 1970.
Photograph:
Ap. J., 143, 192, 1966.
Photometry:
M.N.R.A.S., 152, 79, 1971.
Spectrum:
Ap. J., 143, 192, 1966.
Spectrophotometry:
Ap. J. (Letters), 162, L155, 1970.
Ap. J., 173, 25, 1972.
"Nuclei of Galaxies", 81, 1971.
HI 21cm:
Astr. Ap., 8, 424, 1970.
IAU Symp. No. 44, 264, 1972.

11. 1974UGCA..C...0000N
Re:UGCA 166
UGCA 166:
= I Zw 018 = Mrk 0116
pair of compacts;
"Pair of interconnected blue compacts. Presumably young galaxies
with neutral hydrogen mass of the order 5x10(8)M(sun)" (CSCG);
No.1, m(pg) = 15.6, V = +778 km/sec;
No.2, m(pg) = 17.6, V = +928 km/sec (CSCG 1971)

12. 1971CGPG..C...0000Z
Re:CGPG 0930.5+5527
I Zw 018
Pair of interconnected blue compacts.
Presumably young galaxies
with a neutral hydrogen mass of the order of 5 x 10^8^M_sun_.
No. 1
Spectrum: Emission lines from a moderate continuum,
the Balmer series, He II, [OII], [OIII], [NeIII].
21 cm detected.
= +778 km/sec (Zwicky 1965)
m(pg) = 15.6
No. 2
Situated 5.6 arcsec [south-east] of No. 1.
Spectrum: Emission lines of [OII].
21 cm detected.
= +928 km/sec (Zwicky 1965)
Literature: Zwicky 1964a, 1966a, Chamaraux 1970a.
m(pg) = 17.6


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