A large-scale 12CO (J=1→0) outflow survey (over～110  deg2) were conducted by authors from Purple Mountain Observatory (PMO)  toward the W3/4/5complex and its surroundings using the Purple Mountain  Observatory Delingha 13.7 m telescope. The datawere parts of the Milky  Way Imaging Scroll Painting Project (MWISP) -- a largeongoing project  whose goal is to map CO and its isotopictransitions on the Galactic  plane.

  A total of 459 outflow  candidates were detected, of which 284 were in the Perseus arm, 162 in  the Local arm, 5 inthe Outer arm and 8 in interarm regions. This  indicated that star formation was mainly concentrated to the Galactic  spiral arms (especially the Perseusarm).There were a few cases of star  formationoccurring in the interarm regions, and they were goodexamples  to study relatively isolated star formation.The W3/4/5 complex in the  Perseus arm, especially in the eastern high density layer (HDL) where  the W3 complex neighbors the W4 complex, presented   intensestar  formation activities (see Figure 1). Most of the star formation in  thesecomplexes were likely impacted by theHII regions surrounding  them.The paper was published in the Astrophysical JournalSupplement  Series (2019, ApJS, 242, 19).

 By with Li Yingjie

Fig.  Outflow candidate distribution in the W5 complex.The markers to  describe quality level and classification of outflow candidates are  placed in the bottom left corner of the panel, where 3, 2, and 1 denote  high-, intermediate-, and low-mass outflow candidates (see the criterion  in Section 3.3), respectively. The magenta and red/blue colors of the  shapes and the indices denote bipolar outflow candidates and outflow  candidates that have only a red/blue lobe, respectively.

The  paper was published in the Astrophysical JournalSupplement Series  (2019, ApJS, 242, 19). Detailed information of the paper can be found  at:https://iopscience.iop.org/article/10.3847/1538-4365/ab1e55.