A Search for H2CO 6cm Emission toward Young Stellar Objects III: VLA Observations

We report the results of our third survey for formaldehyde (H2CO) 6 cm maser emission in the Galaxy. Using the Very Large Array, we detected two new H2CO maser sources (G23.01−0.41 and G25.83−0.18), thus increasing the sample of known H2CO maser regions in the Galaxy to seven. We review the characteristics of the G23.01−0.41 and G25.83−0.18 star forming regions. The H2CO masers in G23.01−0.41 and G25.83−0.18 share several properties with the other known H2CO masers, in particular, emission from rich maser environments and close proximity to very young massive stellar objects. Subject headings: ISM: molecules — masers — radio lines: ISM Department of Physics and Astronomy, MSC07 4220, University of New Mexico, Albuquerque, NM 87131 National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 New Mexico Institute of Mining and Technology, Physics Department, 801 Leroy Place, Socorro, NM 87801 Max–Planck–Institut für Astronomie, Königstuhl 17, D–69117 Heidelberg, Germany. Centro de Radioastronomı́a y Astrof́ısica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72, 58089, Morelia, Michoacán, Mexico. University of Puerto Rico at Rio Piedras, Physics Department, P.O. Box 23343, San Juan, PR 00931. Istituto di Radioastronomia, INAF, Sezione di Firenze, Largo Enrico Fermi 5, I-50125 Florence, Italy.