GGD 12-15 star-forming complex consists of 4 smaller regions designated as GGD 12, 13, 14, and 15; the complex is deeply embedded within the Monoceros R2 Molecular Cloud Complex. Notable structures within the complex include a bow shock of gas flowing out of the central star in the east, an extended emission region exhibiting weak filamentary structures in the south, and a dense cluster region with massive disk-bearing YSOs and T Tauri stars.
Star Formation
This dense cluster region contains two prominent stars: a massive B-typeYSO and a Herbig Be star. The dense cluster has an overall median age of ~4 Myr and the massive YSO and the compact cometary H II region are young and have median ages of ~1 Myr. Located in GGD 14, the core of the complex, the compact cometary H II region designated as G213.880-11.837 has been expanding and excited by a B0.5zero-age main sequence (ZAMS) star, while another object designated VLA 7 is the powering source of the molecular outflow that extends ~6 arcminutes from southeast to northwest. The molecular outflow is covering a molecular clump that created VLA 7. The surrounding molecular outflow and H2 emission knots may also have been produced by the B0.5ZAMS star. Star-forming activity in these molecular clouds is proven by the detection of 76 infrared point sources and 5 protostars. Observations of the CO¹⁸O emission line reveals that the molecular clump extends over ~2 pc and has a mass of 2850M☉. The molecular outflow covers this clump through its blueshifted and redshifted lobes; these lobes have masses of 11.7M☉ and 10.6M☉ respectively. A study found that the dense cluster region has about 100 disk-bearing YSOs, with half of them displaying variable star properties. Another study found 90 X-ray sources with infrared sources; 30 of the X-ray sources were previously known and 39 possible X-ray sources.
