Evidence of interacting elongated filaments in the star-forming site
  AFGL 5142
  To probe the ongoing physical mechanism, we studied a wide-scale environment
around AFGL 5142 (area ~25 pc x 20 pc) using a multi-wavelength approach. The
Herschel column density (N(H_2)) map reveals a massive inverted Y-like
structure (mass ~6280 M_sun), which hosts a pair of elongated filaments
(lengths >10 pc). The Herschel temperature map depicts the filaments in a
temperature range of ~12.5-13.5 K. These elongated filaments overlap each other
at several places, where N(H_2) > 4.5 x 10^{21}cm^{-2}. The 12CO and 13CO line
data also show two elongated cloud components (around -1.5 and -4.5 km/s)
toward the inverted Y-like structure, which are connected in the velocity
space. First moment maps of CO confirm the presence of two intertwined
filamentary clouds along the line of sight. These results explain the
morphology of the inverted Y-like structure through a combination of two
different filamentary clouds, which are also supported by the distribution of
the cold HI gas. Based on the distribution of young stellar objects (YSOs),
star formation (SF) activities are investigated toward the inverted Y-like
structure. The northern end of the structure hosts AFGL 5142 and tracers of
massive SF, where high surface density of YSOs (i.e., 5-240 YSOs/pc^2) reveals
strong SF activity. Furthermore, noticeable YSOs are found toward the
overlapping zones of the clouds. All these observational evidences support a
scenario of collision/interaction of two elongated filamentary clouds/flows,
which appears to explain SF history in the site AFGL 5142.
