Abstract
Results of observations of the OH maser in W75N at 18 cm are reported. The observations were obtained on the radio telescope of the Nancay Radio Astronomy Observatory (France) from October 2007 to April 2009. The profiles of the Stokes parameters I, Q, U, and V in the 1665 and 1667 MHz OH lines have been measured. A technique taking into account instrumental polarization has been developed and applied. The emission in the OH lines is strongly polarized both linearly and circularly. The degree of polarization of some emission features reaches almost 100%. There were two flares of the maser emission in 2008–2009. During a flare at a radial velocity of +5.5 km/s, a Zeeman pattern was detected in the 1667 MHz line. The measured intensity of the line-of-sight component of the magnetic field was −1.1 mG, which corresponds to the field being directed away from the observer. The maser flares and the associated enhancement of the magnetic field could be associated with the compression of gas at a shock front.
Similar content being viewed by others
References
D. A. Varshalovich and V. V. Burdyuzha Astron. Zh. 52, 1178 (1975) [Sov. Astron. 19, 705 (1976)].
R. D. Davies, in Galactic Radio Astronomy, Ed. by F. J. Kerr and S. C. Simonson (Reidel, Dordrecht, Holland, Boston, 1974), p. 275.
H. E. Radford, Phys. Rev. 122, 114 (1961).
A. L. Argon, M. J. Reid, and K. M. Menten, Astrophys. J. Suppl. Ser. 129, 159 (2000).
V. L. Fish, M. J. Reid, A. L. Argon, and K.M. Menten, Astrophys. J. 596, 328 (2003).
V. L. Fish, M. J. Reid, A. L. Argon, and X.-W. Zheng, Astrophys. J. Suppl. Ser. 160, 220 (2005).
V. L. Fish and M. J. Reid, Astrophys. J. Suppl. Ser. 164, 99 (2006).
V. L. Fish and M. J. Reid, Astrophys. J. 656, 952 (2007).
M. Szymczak and E. Gérard, Astron. Astrophys. 494, 117 (2009).
B. Zuckerman, D. F. Dickinson, J. A. Ball, et al., Astron. J. 73, S210 (1968).
W. T. Sullivan, III and J. H. Kerstholt, Astron. Astrophys. Suppl. Ser. 26, 399 (1976).
A.V. Alakoz, V. I. Slysh, M.V. Popov, and I. E. Val’tts, Pis’ma Astron. Zh. 31, 422 (2005) [Astron. Lett. 31, 375 (2005)].
P. J. Harvey, R. S. Booth, R. D. Davies, et al., Mon. Not. R. Astron. Soc. 169, 545 (1974).
N. J. Evans, II, R. M. Crutcher, and W. J. Wilson, Astrophys. J. 206, 440 (1976).
A. D. Haschick, M. J. Reid, B. F. Burke, et al., Astrophys. J. 244, 76 (1981).
R. P. Norris, R. S. Booth, P. J. Diamond, and N. D. Porter, Mon. Not. R. Astron. Soc. 201, 191 (1982).
E. E. Baart, R. J. Cohen, R. D. Davies, et al., Mon. Not. R. Astron. Soc. 219, 145 (1986).
V. I. Slysh, I. E. Val’tts, and V. Migenes, Astron. Zh. 78, 1073 (2001) [Astron. Rep. 45, 942 (2001)].
V. I. Slysh, V. Migenes, I. E. Val’tts, et al., Astrophys. J. 564, 317 (2002).
V. I. Slysh, I. E. Val’tts, and V. Migenes, Astron. Zh. 79, 240 (2002) [Astron. Rep. 46, 216 (2002)].
B. Hutawarakorn, R. J. Cohen, and G. C. Brebner, Mon. Not. R. Astron. Soc. 330, 349 (2002).
V. I. Slysh and V. Migenes, Mon. Not. R. Astron. Soc. 369, 1497 (2006).
M. D. Gray, B. Hutawarakorn, and R. J. Cohen, Mon. Not. R. Astron. Soc. 343, 1067 (2003).
V. L. Fish, M. J. Reid, K. M. Menten, and T. Pillai, Astron. Astrophys. 458, 485 (2006).
I. S. Shklovsky, Astron. Zh. 46, 3 (1969).
M. Szymczak and E. Gérard, Astron. Astrophys. 423, 209 (2004).
D. H. Roberts, J. F. C. Wardle, and L. F. Brown, Astrophys. J. 427, 718 (1994).
G. V. Rozenberg, Usp. Fiz. Nauk 56, 77 (1955).
Physical Encyclopedia, Ed. by A. M. Prokhorov (Bol. Ross. Entsiklop., 1994), Vol. 4, p. 690 [in Russian].
E. E. Lekht, V. I. Slysh, and V.V. Krasnov, Astron. Zh. 84, 1070 (2007) [Astron. Rep. 51, 967 (2007)].
E. E. Lekht, V. I. Slysh, and V.V. Krasnov, Astron. Zh. 86, 460 (2009) [Astron. Rep. 53, 420 (2009)].
Author information
Authors and Affiliations
Additional information
Original Russian Text © V.I. Slysh, M.I. Pashchenko, G.M. Rudnitskiĭ, V.M. Vitrishchak, P. Colom, 2010, published in Astronomicheskiĭ Zhurnal, 2010, Vol. 87, No. 7, pp. 655–666.
Rights and permissions
About this article
Cite this article
Slysh, V.I., Pashchenko, M.I., Rudnitskiĭ, G.M. et al. Polarization observations of the OH maser W75N on the Nançay radio telescope. Astron. Rep. 54, 599–610 (2010). https://doi.org/10.1134/S1063772910070048
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1063772910070048