Open Access Repository

The brightest known H2CO maser in the Milky Way: G339.88-1.26


Downloads per month over past year

Chen, X, Shen, Z-Q, Ellingsen, SP ORCID: 0000-0002-1363-5457, Li, X-Q, Yang, K, Chen, H-Y and Dong, J 2017 , 'The brightest known H2CO maser in the Milky Way: G339.88-1.26' , Astrophysical Journal Letters, vol. 851, no. 1 , pp. 1-5 , doi: 10.3847/2041-8213/aa9b2c.

Chen_2017.pdf | Download (622kB)

| Preview


We report the detection of the strongest 101-111 6 cm H2CO emission in our Galaxy. The detection toward the massive star-forming region G339.88-1.26 was made using the Shanghai Tianma radio telescope (TMRT). The G339.88-1.26 star formation region hosts one of the strongest 6.7 GHz methanol masers and has an accompanying collimated, ionized jet seen in radio continuum free–free emission. The peak flux density of the detected H2CO emission is ~19 Jy, one order of magnitude stronger than the nine previously known H2CO maser sources. The corresponding luminosity is also brighter than has been observed in previous H2CO maser sources, even those detected in the Central Molecular Zone of our Galaxy. A TMRT on-the-fly map of the region shows a point-like source structure and this, combined with the spectral characteristics of the H2CO emission (multiple, narrow components), leads us to conclude that the detected H2CO emission is masing (with a brightness temperature in excess of 104 K). The detection of a very strong H2CO maser in G339.88-1.26 suggests that ionized jet/outflow environments might provide efficient maser pumping for this transition, with the ionized jet/outflow-driven shock causing collisional excitation, and are also able to provide additional seed photons for maser amplification of the radio continuum emission.

Item Type: Article
Authors/Creators:Chen, X and Shen, Z-Q and Ellingsen, SP and Li, X-Q and Yang, K and Chen, H-Y and Dong, J
Keywords: ISM: molecules, masers, radio lines: ISM, stars: formation
Journal or Publication Title: Astrophysical Journal Letters
Publisher: Institute of Physics Publishing Ltd.
ISSN: 2041-8205
DOI / ID Number: 10.3847/2041-8213/aa9b2c
Copyright Information:

Copyright 2017 The American Astronomical Society. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0)

Related URLs:
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page