Interarm islands in the Milky Way -- the one near the Cygnus spiral arm
  This study extends to the structure of the Galaxy. Our main goal is to focus
on the first spiral arm beyond the Perseus arm, often called the Cygnus arm or
the Outer Norma arm, by appraising the distributions of the masers near the
Cygnus arm. The method is to employ masers whose trigonometric distances were
measured with accuracy. The maser data come from published literature, having
been obtained via the existing networks (US VLBA, the Japanese VERA, the
European VLBI, and the Australian LBA). The new results for Cygnus are split in
two groups: those located near a recent CO fitted global model spiral arm, and
those congregating within an interarm island located halfway between the
Perseus arm and the Cygnus arm. Next, we compare this island with other similar
interarm objects near other spiral arms. Thus we delineate an interarm island
(6 x 2 kpc) located between the two long spiral arms (Cygnus and Perseus arms);
this is reminiscent of the small Local Orion arm (4 x 2 kpc) found earlier
between the Perseus and Sagittarius arms, and of the old Loop (2 x 0.5 kpc)
found earlier between the Sagittarius and Scutum arms. Various arm models are
compared, based on observational data (masers, HII regions, HI gas, young
stars, CO gas).
