Far-infrared loops in the 2nd Galactic Quadrant

We present the results of an investigation of the large-scale structure of the diffuse interstellar medium in the 2nd Galactic Quadrant (90°≤l≤180°). 145 loops were identified on IRAS-based far-infrared maps. Our catalogue lists their basic physical properties. The distribution clearly suggests that there is an efficient process that can generate loop-like features at high Galactic latitudes. Distances are provided for 30 loops. We also give an observational estimate of the volume filling factor of the hot gas in the Local Arm, 4.6%≤f_2nd<6.4%.

Appendices A-C are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/418/131