Images of the two observed areas in the first (top) and fourth (bottom) Galactic quadrant with Herschel/SPIRE at 500 μm. Green dots indicate protostellar objects in the entire field while blue triangles show protostellar clumps at the bar, i.e. at a distance 5 < d < 7 kpc in the first quadrant and 10 < d < 12 kpc in the fourth quadrant (see Sect. 4 for more details). Known star forming regions from Blum et al. (1999), Leahy & Tian (2008), Zavagno et al. (2010), Urquhart et al. (2011), Sewilo et al. (2011) are labeled in yellow.