L 1274: A multiwavelength study of a dark cloud in the Cep -Cas void

¹ Department of Astronomy of the Loránd Eötvös University, Pázmány Pétér sétány 1/A, 1117 Budapest, Hungary
² Onsala Space Observatory, 439 92 Onsala, Sweden
³ Astronomical Observatory, Volgina 7, 11160 Belgrade, Serbia, Yugoslavia
⁴ Radioastronomisches Institut der Universität Bonn, Auf dem Hügel 71, 53121 Bonn, Germany

Corresponding author: S. Nikolić, silvana@oso.chalmers.se

Received: 8 November 1999
Accepted: 4 December 2000

Abstract

We present a multiwavelength study of L 1274, a dark molecular cloud in the Cep -Cas void. From objective prism spectroscopy we derive a distance of pc to the cloud. CO maps reveal a slightly elongated molecular cloud with a diameter of about 2 pc. Maps in ¹²CO (1-0), ¹³CO (1-0) and ¹²CO (2-1) indicate two distinct features: a "main body" and an adjacent "ridge". The kinetic temperature of the CO gas is 10-12 K, calculated by a non -LTE method. The total gas mass of the main body is estimated from the CO data to be 25 -45 . We find a large difference between CO -inferred gas mass and virial mass, a property usually attributed to HLCs. However, the derived mean density of H₂ is at least an order of magnitude larger than typical for HLCs, i.e. similar to ordinary dark cloud cores. We discuss the validity of our mass estimates and the possibility of an external disturbance, e.g. a passage of a supernova induced shock-front.