Sunday, January 4, 2015

Photographing Astronomers

Giovanni talking at his 50th anniversary celebration, Cambridge, MA (May 28, 2009)

From time to time I am asked to take pictures at astronomy meetings. It is not an easy task for me, since I don't have any formal training to cover events and my equipment is not ideal for low light. I also lack the confidence to position myself where I should be for composing the best images, being afraid of distracting the speaker or the audience with my wandering around. So I generally sit in the front row near the podium, with a fast prime lens trying to capture as much natural light as possible. It doesn't make for the sharpest pictures, but the lectern light (or laptop screen) often provides an interesting illumination. Plus I have the advantage, with respect to professional photographers, to understand what's going on in the talk, predicting in advance when the good moments are coming and when I can expect an interesting expression from the speaker. The last time I wore my photographer's hat at an astronomy meeting was last spring, for the retirement celebration of a faculty member in my department. I am still working on the photos; today's post is from a previous event, celebrating the 50th anniversary of science of one of my mentors, Giovanni Fazio.

Giovanni talking with Mike Warner
Giovanni is the person that made it possible for me to work in the US. It was him, almost 20 years ago, that suggested I should apply for a fellowship from the Smithsonian Institution to complete my Ph.D. at the Harvard-Smithsonian Center for Astrophysics, where he is based. I was supposed to stay there for one year, but then I stayed the whole 3 years necessary to complete my program. After that I found a postdoc in the same institution, until I was hired by Giovanni as staff scientist to work on the infrared camera he was building for NASA's Spitzer Space Telescope. I worked with Giovanni for the whole cryogenic mission of Spitzer (that is, until the camera consumed its refrigerant and the program was scaled back). I am still collaborating with him, from Iowa where I moved after I left the Spitzer group. Giovanni is the best boss anybody could hope to work for; in many years of working together, I never heard him raising his voice even once, or order somebody to do something; when a task needed to be done, it was just enough that he mentioned it in our group meetings: somebody would volunteer to do it, with everybody's help, just out of Giovanni's charisma. This is how it is working with Giovanni.

Frank Licata
Despite his italian name, Giovanni was born in San Antonio Texas and does not speak italian. His parents emigrated from different parts of Italy (I believe Tuscany and Sicily) and met when they were already in the US. Their respective dialects were so different that English was their only common language. Giovanni grew up at a time when it was easier for talented kids to go to top schools regardless of their family's economic conditions: after completing his undergraduate studies at a liberal arts Catholic school in Texas he went-on to do its Ph.D. in Physics at MIT. Giovanni background was particle physics; the poster held by Frank Licata in the photo at the right shows a young Giovanni looking at a gamma ray detector that he flew in the 1960s with a balloon, to measure cosmic radiation hitting the stratosphere. These were pioneering years for science: Giovanni is fond to tell the story of how, early in his career, he was tasked to manually insert the target for an experiment at the Brookhaven accelerator. The way you would do it now would be to shut down the accelerator, make a gazillion radiation check, then walk-in with some protective equipment and replace the target: safe, but requiring days of downtime between pulses. The way they did it then was more efficient: replace the target between one pulse and the next, avoiding to be fried by the "beam-of-death" by calculating the exact interval in which the accelerator was down between pulses. Apparently this technique was not recommended even at the time, and the horrified management tried to discourage the exercise by surrounding the target area with a tall fence (to no avail, as they only had to factor-in the fence climbing time as part of the target replacement procedure). This technique was not perfect: Giovanni jokes that they knew the cross section (how much of the beam was absorbed) of everybody in the lab.

Jeffrey Hoffmann
From particle physics Giovanni moved to particle astrophysics (pioneering telescopes lifted by balloon flights to allow detection of radiation otherwise absorbed by the thick lower atmosphere) and was one of the founders of gamma ray and x-ray astronomy. He then moved further down the energy spectrum, and become one of the pioneers of infrared astronomy (this is how I met him). Giovanni was one of the proposers of the NASA space infrared great observatory, the one that would later become the Spitzer Space Telescope. Spitzer was originally meant to fly with the Shuttle, the same as the Hubble Space Telescope, and Giovanni was the principal investigator of an early prototype that flew with the Shuttle during the Spacelab 2 mission (STS-51-F, in 1985). The small photo on the left shows NASA astronaut Jeffrey Hoffmann, toasting to Giovanni during the celebration dinner. Hoffmann was one of the Shuttle mission specialists working on NASA astronomy experiments; while not involved with Giovanni's Shuttle infrared telescope he was part of the STS-61 crew that refurbished the Hubble telescope by fixing its "blurred" optics.

Spitzer was finally launched with a Delta II "Heavy" in 2003, almost 25 years after being initially proposed. It carried the camera designed by Giovanni and his group, which is still taking images well after its designed operational time (the telescope primary mission ended in 2009 when the liquid helium coolant was exhausted). Spitzer is still the source of the largest fraction of the data I use in my research. Giovanni is also still going strong, working towards the next mission that will carry one of his instruments to space into the next decade.

Irwing Shapiro (former CfA director) telling some animated story about Giovanni

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