The richness of compact radio sources in NGC 6334D to F
  The presence and properties of compact radio sources embedded in massive
star-forming regions can reveal important physical properties about these
regions and the processes occurring within them. The NGC 6334 complex, a
massive star-forming region, has been studied extensively. Nevertheless, none
of these studies has focused in its content in compact radio sources. We report
on a systematic census of the compact radio sources toward NGC 6334, and their
characteristics. This will be used to try and define their very nature. We use
VLA C band (4-8 GHz) archive data with 0.36" of spatial resolution and noise
level of 50 uJy/bm to carry out a systematic search for compact radio sources
within NGC 6334. We also search for infrared counterparts to provide some
constraints on the nature of the detected radio sources. A total of 83 compact
sources and three slightly resolved sources were detected. Most of them are
here reported for the first time. We found that 29 of these 86 sources have
infrared counterparts and three are highly variable. Region D contains 18 of
these sources. The compact source toward the center, in projection, of region E
is also detected. From statistical analyses, we suggest that the 83 reported
compact sources are real and most of them are related to NGC 6334 itself. A
stellar nature for 27 of them is confirmed by their IR emission. Compared with
Orion, region D suffers a deficit of compact radio sources. The infrared
nebulosities around two of the slightly resolved sources are suggested to be
warm dust, and we argue that the associated radio sources trace free-free
emission from ionized material. We confirm the thermal radio emission of the
compact source in region E. However, its detection at infrared wavelengths
implies that it is located in the foreground of the molecular cloud. Three
strongly variable sources are suggested to be magnetically active young stars.
