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Exploring Mysteries in Star Formation

Story: The integrated emission of the NH3 (1,1) and (2,2) inversion transitions toward the young high-mass star IRAS 20126+4104, as compared to the bipolar SiO outflow (Cesaroni et al. 1999). The NH3 data, obtained with the VLA reveals a compact rotating disk-like structure surrounding a massive protostellar object (Zhang et al. 1998).

Story: The integrated intensity of the combined NH3 (1,1) emission in white solid contours overlaid on the Spitzer 8 micron image in logarithmic color scales of an IRDC G28.37 (Wang et al. 2008). The star symbols mark the 24 micron emission peaks observed with MIPS/Spitzer. The cross symbols mark water maser emission detected with the VLA (Wang et al. 2006). The thin dashed line indicates the 50 of the sensitivity level of the 7 pointing mosaic in NH3. The NH3 data have a resolution of 5'' x 3'', shown as the shaded ellipse at the lower-left corner of the panel. The thick dashed circles mark the SMA fields presented in Zhang et al. (2009). The studies of G28.37 reveals a quescent region in P1 which appears to be at the very start of a cluster formation, in contrast to the more evolved 'hot molecular core' phase in P2. The SMA image of the P1 region shows a strong of 5 young dust cores resulting from the initial fragmentation of molecular cloud.

Story: The background shows a three-color Spitzer image of the massive star-forming region G31.41. Blue color represents the Spitzer image at 3.6 micron, green at 8 micron, and red at 24 micron. The zoom-in region depicts the 870 micron dust emission obtained from the Submillimeter Array of the massive hot molecular core in G31.41 (color and contour image) superposed with bars outlining the direction of magnetic fields. Pictured in the bottom of the image is the SMA stop Mauna Kea, Hawaii. This study by Girart, Rao, Zhang, Beltran and Estalella (Science, 2009) demonstrates the importance of magnetic fields during the collapse of massive molecular cloud core. Credit: Josep Miquel Girart (CSIC-IEEC), Nimesh Patel (Harvard-Smithsonian Center for Astrophysics) and Manel Carrillo