A T N F    D a i l y    A s t r o n o m y    P i c t u r e

5th of June 2018
Methanol masers in NGC 253
by Chen et al.
Chen et al. have used the Jansky Very large Array (JVLA) to follow-up earlier Australia Telescope Compact Array (ATCA) observations of 36.2 GHz class I methanol maser from starburst galaxy NGC 253, which lies about 11 million light years away. Combining the JVLA data with the previous ATCA observations and single-dish observations from the 65m Shanghai TianMa Radio Telescope, they show that the 36.2 GHz methanol emission consists of both extended (~300 light year) and compact (~3 light year) structures. The strongest components have a brightness temperature greater than 1000K, much higher than the maximum kinetic temperature of ∼100 K of the thermal methanol emission from NGC 253. These observations demonstrate for the first time the presence of maser emission from a class I (collisionaly excited) methanol transition in an external galaxy.

The figure shows a comparison of the ATCA (1.5km array), JVLA (A-array), and TianMa observations of the 36.2 GHz methanol emission in NGC 253. The black contours show the integrated methanol emission detected by the ATCA, red stars denote the peak positions of the four compact methanol components detected by the JVLA, and two methanol spectra detected by the TianMa 65m telescope are presented in the top-right corner. More details are given in the paper published in The Astrophysical Journal Letters.

<<   |   archive   |   about   |   today   *   ATNF   |   Parkes   |   ATCA   |   Mopra   |   VLBI   |   ASKAP   |   >>