A.10. LGS3 LGS3 has only seven definable regions, five of which were useable.
This was the second closest galaxy in our survey at a distance of 0.6 Mpc, so we
should be able to see any star formation that might have been there. Despite
these favorable conditions, we still see nearly no star formation over the last
billion years. This galaxy has no measurable H II regions.
The H I cloud in the vicinity of LGS 3 was noted by Hulsbosch & Wakker
(1988) and is quite close to the galaxy, but the velocity centroid of
most of the H I differs from that of the galaxy by about 50 km s^-1^.
This galaxy was mapped with the VLA by Young & Lo (1997), who found an
H I cloud centered on the dSph within a few km s^-1^ of the velocity of
LGS 3 and a total H I mass of 4 x 10^5^ M_sun_. Smoothing of the LDS H I
profile at the position of the galaxy shows both the -285 km s^-1^
component and a component centered at about -340 km s^-1^. A hint of
the more extreme velocity can be seen in the 140" spectrum shown by
Young & Lo (1997). The probability of two HVCs seen along the same line
of sight that are this compact is about 10^-2^ (see section 2). While
the large velocity difference between the cloud shown in Figure 2 and
the cloud mapped by Young & Lo (1997) is puzzling, the relation of the
dSph to the cloud bears some resemblance to the other systems pictured
in Figure 1. We discuss in section 4 the possibility that the more
negative velocity component may result from ram-pressure stripping.
Although the emission detected by Young & Lo (1997) is not seen in
either the map or the spectrum shown in Figure 1, both are consistent
with their detection. The peak flux density of this galaxy observed at
the 140" telescope is about 110 mJy, corresponding to an expected
antenna temperature of 0.021 K when observed with the Dwingeloo
telescope. This is the strength at which the feature is seen, within the
noise, in the LDS at the position of the galaxy. The spectrum shown in
Figure 1 is an average of six positions at which the H I is detected;
the expected peak temperature of that feature is lowered by yet another
factor of 2.5; a feature of that strength is too weak to be detected.
Both the spectrum and the map of this source are consistent with the
observations of Young & Lo (1997).
Pisces (LSB-3). Tikhonov and Makarova (1996). The CCD survey of Lee (1995) is
not deep enough to construct the LF near the magnitude V(5). The comment is the
same as for Phoenix.
LGS 3 is one of the lowest surface brightness objects in our sample. It appears
partially resolved into stars and knots embedded in a very diffuse and
amorphous body. On our frames it appears more elongated than on POSS prints.
There is no pronounced nucleus visible. About 6 faint knots are clustered near
to the center, and a few further knots are visible in the periphery. We
measured the magnitudes and colours of the 7 brightest knots. Three central
knots have B-V colours in the range 0.18/0.53, and peripherial knots are
redder (0.62 < B-V < 1.11). Part of these knots may be projected foreground
stars. Central spikes in both light profiles are caused by the bright knots.
According to Tikhonov & Sazonova(1994) the distance of LGS 3 is about 0.58 Mpc.