Interstellar polarization at high galactic latitudes from distant stars

VI. Extended polarization map and connection with the local spiral structure

Tuorla Observatory, 21500 Piikkiö, Finland e-mail: andrei@astro.utu.fi; pekkatee@astro.utu.fi

Corresponding author: A. Berdyugin, andrei@astro.utu.fi

Received: 8 October 2001
Accepted: 4 January 2002

Abstract

We present new interstellar polarization measurements for 116 stars at high galactic latitudes. Our data show that Markkanen's cloud – the main polarization structure seen in the North Galactic Pole area () extends further towards lower latitudes. Especially, we have found a new dust formation in the area  < , . Interstellar polarization in this part of the sky peaks at , which gives a lower limit to the extinction . Polarization vectors in this cloud are very well aligned along the direction of . On the IRAS 100 micron map this dust structure shows up as a bright emission area. We discuss the new polarization map extending from circumpolar to lower latitudes and point out features which suggest that Markkanen's cloud may be a part of the dust lane in the inner edge of the local spiral or spur.