3D Mapping of the MASER disk in NGC 1194

Data-driven 3D Animation

Animated data visualization which shows the velocities and positions of water vapor MASER emission regions in the active galaxy NGC 1194.

MASER is an acronym for „Microwave Amplification by Stimulated Emission of Radiation“. Essentially, this is the same process as for LASER, except that the amplified light is emitted at microwave frequencies rather than in the optical. The result is highly intense radiation at a precise frequency of 22.2 GHz. Due to an effect called Doppler effect the frequency that we observe from these regions changes if the source moves towards or away from us. Just light the sound of an ambulance changes which passes by our ears. Astronomers can use this frequency shift to analyze the movement of gas in distant galaxies.

The animation shows a 3D data visualization of MASER spots in the active galaxy NGC 1194. The galaxy is 182 million light years away from Earth! Using more than 7 years of different combinations of radio observations, graduate student Eugenia Fink (née Litzinger, Uni Wuerzburg) analyzed the velocities of maser emission regions which orbit around the central black hole of the galaxy. She was able to measure the distance of each maser spot and derive the size of the disk. With a diameter of 16 – 52 light years it belongs to the largest maser disks known today. However, due to the distant of the galaxy this angular size measures only 20 milliarcseconds, less than 1/1000 of the moon.

Acknowledgements

The data visualization project was done in collaboration with Eugenia Fink (née litzinger, University of Würzburg, Germany, responsible for scientific analysis) and Anda Iosip (Sound).

Data

GBT single-dish observations between 2006 and 2013 (K-band , 22 GHz, Gregorian K-band receiver till April 2011, since May 2011 K-band Focal Plane Array (KFPA)) and VLBI observations of the VLBA, Effelsberg 100m telescope and the GBT (2007/2008 VLBA with GBT, 2012 VLBA with Effelsberg and GBT).