  Despite their carbon-rich photospheres, silicate carbon stars show evidence
of oxygen-rich circumstellar material, which is considered to exist in disks.
Silicate carbon stars represent interesting cases that allow us to study the
possible effects of binarity on stellar evolution and the mass loss accompanied
by the formation of disks. We present a small survey of the 22 GHz H2O masers
toward 10 silicate carbon stars with much better sensitivity than the previous
observations. We observed our sample with the Karl G. Jansky Very Large Array
(VLA) using the most expanded configuration (A-configuration) with a maximum
baseline of 36 km. For some of our program stars with noisy IRAS Low Resolution
Spectra (LRS), we present new mid-IR spectra obtained with the Very Large
Telescope Interferometer and the Spitzer Space Telescope. We detected the H2O
masers toward 5 out of 10 silicate carbon stars (EU And, V778 Cyg,
IRAS06017+1011, V1415 Cyg, and NC83=V1945 Cyg), with NC83 being new detection.
No H2O masers were detected toward BM Gem, IRAS07221-0431, IRAS08002-3803,
IRAS18006-3213, and HD189605. The velocity separation between the most blue-
and red-shifted maser features is 10--14 km/s. If we assume that the masers
originate in circum-companion disks, the measured velocity separations
translate into a lower limit of the rotational velocity of 5--7 km/s, and the
upper limit of the radius of the maser emitting region is estimated to be
10--68 AU for a companion mass of 0.5--1.7 Msun. The new mid-IR spectra of
NC83, IRAS06017+1011, and HD189605 confirm the 10 micron silicate emission. The
latter two stars show a bump at ~11.5 micron, which is presumably due to SiC
originating in the ongoing mass loss from the carbon-rich primary star, not due
to crystalline silicate. We also report on the detection of the UV flux at 2271
A toward HD189605.
