The galactic plane region near l=93 degrees I. HII region NRAO 655

We present new Canadian Galactic Plane Survey radio continuum and lambda 21 cm HI line ol,observations of NRAO 655 (G93.4+1.8). plus radio recombinati on line observations, anti optical Her-line observations. The radio spectru m of NRAO 655 confirms its emission as thermal. From the lambda 21 cm HI da ta we find an atomic hydrogen cavity associated with this object at v simil ar or equal to -71.5 kms(-1). The cavity corresponds in position and size t o the brightest radio continuum emission from NRAO 655. The corresponding k inematic distance is: 8.8 kpc, placing: NRAO 655 in the Perseus Arm. NRAO 6 55's linear size is therefore 70 pc x 130 pc. To confirm the lambda 21 cm H I velocity. we present the first recombination line detection of NRAO 655 ( H158a line, v: similar or equal to -71 km s(-1) ). and the first observatio ns of a molecular cloud coinciding with NRAO 655 (at v similar or equal to -72 km s(-1)). The first optical detection of lambda 656 nm Ha emission lin e features in NRAO 655 is also presented. and the H alpha emission line bri ghtness is determined. We suggest that the eastward extension of tills stro ngly asymmetric object originates ill a champagne outflow. and we estimate its age. We show that a single early-type star cannot bt, responsible for t he outflow, whereas a group of later-type stars would suffice. A partial HI shell iii seen adjacent to the brightest part of NRAO 655: we suggest that it has been formed by dissociation of H-2 in the molecular cloud.