Possibility of Measuring the Width of Narrow Fe II Astrophysical Laser Lines in the Vicinity of Eta Carinae by means of Brown-Twiss-Townes Heterodyne Correlation Interferometry

摘要

We consider the possibility of measuring the true width of the narrow Fe IIoptical lines observed in spectra of the Weigelt blobs in the vicinity of EtaCarinae. The lines originate as a result of stimulated amplification ofspontaneous emission of radiation in quantum transitions between energy levelsshowing inverted population (Johansson & Letokhov, 2002, 2003, 2004). The linesshould have a subDoppler spectral width of 30-100 MHz, depending on thegeometry of the lasing volume. To make measurements with a spectral resolutionof R>10^7 and an angular resolution better than 0.1 arcsec, we suggest the useof the Brown-Twiss-Townes optical heterodyne intensity correlationinterferometry. The estimates made of the S/N ratio for the optical heterodyneastrophysical laser experiment imply that it is feasible.