Aztec Quasar Pilgrimage

March 24, 2009

Twice each year, at the equinox, the feathered serpent Quetzalcoatl returns to his home at the Great Pyramid of Cholula. I was there with my family to welcome him this Saturday, having travelled to INAOE in Mexico to give my UKIDSS/VO colloquium. Quetzalcoatl must be a shy chap. It seems it needs a few thousand people to encourage him home by singing, dancing, eating gorditas, drinking pulque, and jumping over fires wearing absurdly large head-dresses. At twilight, we climbed the ancient pyramid towards the Christian church planted on its top. Halfway we turned and looked back towards Popocatapetl, smoking in the middle distance. It is just so huge and dramatic. How can you not feel stirred ? The church was full of icons of Mary / Diana / Earth Mother, and several images of the Sacred Heart, which seemed gruesomely appropriate. These things are so powerful, I think it is a mistake to think of religion simply as ignorance. Rationality is an insight, a liberation, that battles against some of our wiring.

Back down among the festival tents, there were in fact many astronomers in attendance, showing the locals how to make paper models of the Moon and of Stereo A and B. I am glad to report these stalls were very popular. Almost as popular as the pulque.

This morning I walked into INAOE, in the nearby village of Tonantzintla. I walked past the old Schmidt telescope, part of the original 1940s observatory founded by Guillermo Haro. Like my visit to Byurakan almost two years ago, this was a kind of historical pilgrimage. Haro was I believe the first to use the idea of a Schmidt objective prism to search systematically for blue things. He found all sorts of fascinating things, including discovering the jet-like structures in forming stars now known as Herbig-Haro objects. But his lists of blue things included star forming galaxies, and blue “stars” which later turned out to be quasars. (Ton 202 is a favourite of mine, being one of the quasars where my colleague Makoto Kishimoto uncovered the Balmer edge expected from an accretion disc atmosphere, and the nu**1/3 SED in the infrared – see post here). Today Roberto Terlevich told me that Haro worked with Ambartsumian, and actually convinced Markarian to undertake his historic survey – at first Markarian wasn’t interested. Apparently Haro was eventually awarded the Lenin Prize.

It is so strange to think of those quasars sitting there, in a list in Haro’s office, all those years until somebody knew what they were. What mysteries are hidden today, unrecognised in an anonymous list on somebody’s laptop ?