New ex-OH maser detections in the northern celestial hemisphere

Abstract

Aims.Molecular masers, including methanol and hydroxyl masers, and in particular the ones in excited rotational states (ex-OHmasers), are one of the most informative tools for studying star-forming regions. So, the discovery, of new maser sources in theseregions is of great importance. Many studies and surveys of ex-OH maser sources have been carried out in the southern celestialhemisphere, but only a few have been done in the northern hemisphere. The specific aim of this work is to close this gap.Methods.The star-forming regions in the northern hemisphere with known active methanol masers were observed to search for newex-OH maser sources with the 32 m and 16 m radio telescopes of the Ventspils International Radio Astronomy Centre (VIRAC).Results.Three OH maser lines in the excited state at the 6035 MHz in three northern hemisphere star-forming regions are detected.The maser 189.030+0.783 was previously known, but we suggest this maser is a possible variable. We confirm recent detections ofthe ex-OH masers 85.41+0.00 and 90.92+1.49 by other authors. The magnetic field strength in the masering regions is estimated byusing right circular polarization (RCP) and left circular polarization (LCP) pair splitting. The high-velocity resolution provides uswith an estimation of a comparatively small magnetic field strength for the 189.030+0.783 and 90.92+1.49 star-forming regions

6 pages 1 figure 4 tables

References in corpus (7)

• On the Relationship of UC H II Regions and Class II Methanol Masers: I. Source Catalogs
• Review of Zeeman Effect Observations of Regions of Star Formation
• A 6.7 GHz Methanol Maser Survey II. Low Galactic Latitudes
• Structure of W3(OH) from Very High Spectral Resolution Observations of 5 Centimeter OH Masers
• Enhanced density and magnetic fields in interstellar OH masers
• Masers and star formation
• OH maser toward IRAS 06056+2131: polarization parameters and evolution status