OH Counterparts for H[TINF]2[/TINF]O Masers in the Galactic Center: Evolved Stars Instead of Signs of Recent Star Formation

Abstract

We present the detection of OH maser emission associated with the H2O masers recently found in the Galactic center by Levine et al. and by Yusef-Zadeh & Mehringer. The 1612 MHz OH masers were found in high-sensitivity maps created by combining 17 VLA observations taken by van Langevelde et al. as well as in new observations with the ATCA. Both Levine et al. and Yusef-Zadeh & Mehringer consider the H2O emission to be clues for recent massive star formation, by associating it with a supergiant and an H II region. The newly found OH masers show the typical double-peaked spectra for evolved oxygen-rich stars and do not stand out among other OH/IR stars in this region, either in H2O or OH maser characteristics. We conclude that the H2O maser detections are associated with evolved, low- to intermediate-mass stars, and that these H2O masers thus cannot be regarded as signposts for massive young stars or star-forming regions.