Hostname: page-component-7c8c6479df-xxrs7 Total loading time: 0 Render date: 2024-03-28T11:40:51.543Z Has data issue: false hasContentIssue false

Variability of Water Masers in W49N: Results from Effelsberg Long-term Monitoring Programme

Published online by Cambridge University Press:  16 July 2018

Busaba H. Kramer
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany email: bkramer@mpifr-bonn.mpg.de National Astronomical Research Institute of Thailand, 260 Moo 4, T. Donkaew, Amphur Maerim, Chiang Mai, 50180, Thailand
Karl M. Menten
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany email: bkramer@mpifr-bonn.mpg.de
Alex Kraus
Affiliation:
Max-Plank-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany email: bkramer@mpifr-bonn.mpg.de
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present the results from an ongoing long-term monitoring of the 22 GHz H2O maser in W49N with the 100-m Effelsberg radio telescope from February 2014 to September 2017. The unique Effelsbergs spectral line observation capability provides a broad velocity range coverage from −500 to +500 km s−1 with a spectral resolution better than 0.1 km/s. Following the strong major outburst in W49N in late 2013, we have started a long-term monitoring programme at Effelsberg. The major outburst feature (up to 80,000 Jy at VLSR − 98 km s−1) faded away by June 2014. However, we found that the site is still active with several high velocity outbursts (both blue and redshifted). Some features appear at extremely high velocities (up to ±280 km s−1) and show rapid flux variations within a 1-2 month period. This sub-year scale variability implies that the water masers could be excited by episodic shock propagation caused by a high-velocity protostellar jet.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

Honma, M., Choi, Y. K., Bushimata, T., et al., 2004, PASJ, 56, L15Google Scholar
Kramer, B. H., et al. (in prep).Google Scholar