Turno #1 as an ESO/ALMA Fellow

In January (2016) I returned to ALMA for my first "turno" (shift) as an ESO/ALMA fellow.  For the next three years, I will spend about 8 days every month at ALMA as part of my "duties" for the fellowship, but to me "duties" does not capture the experience.  Duty implies more obligation rather than opportunity. Opportunity to learn the intricacies of ALMA, opportunity to operate the world's largest astronomical project, opportunity to work with people from all over the world, opportunity to experience life in the "driest place on earth".  These duties, or rather opportunities, are an important reason why I chose this job.  

ALMA Operations Support Facility.
Click here for larger, zoomable panoramic image.

Posts in this blog from 2012 January -- March, plus a recap here, documented my experience as a visiting scholar (term that we made up because I was possibly the first US grad student to weasel her way into the project) during the "Early Science" phase of ALMA operations.  To explain concisely, in 2012 ALMA was already on the path to become the largest radio telescope array, with 16 antennas (each with 12-m diameter) and counting.  In 2013, ALMA was formally inaugurated with 50 functioning antennas (now with 12-m and 7-m diameter antennas).  In 2014 the phase known as "Commissioning and Science Verification" transformed into "Extension and Optimization of Capabilities", and full operations include 66 antennas.  

I wrote in a previous post (and was happy to revisit what I acknowledged 3 years ago): 

"ALMA has been integral in the development of my own career."

At the time I hoped, but did not know, that I would have the opportunity to return here for work after finishing my PhD.  In the meantime, we (with my PhD advisor Héctor Arce at Yale, and collaborators) actively applied to use ALMA for our research, and I was successful in publishing data from observations performed in 2014.  We have more data to analyze, and more observations in the queue, and when data are delivered it's like opening up presents on Christmas morning.  In other words, in the meantime, I realized how scientifically beneficial ALMA can be.

Hence my fortune in returning to ALMA with regularity, which I intend to document in this blog.  Now I'm on the "operations" side of delivering fantastic data to the astronomy community.  Just as my own career has developed in the last few years since being at ALMA, ALMA has developed substantially as well.  A few changes, a few "appearances", and a "disappearance" of sorts.   To conclude this post, I'll document these with photos that I took during my January turno.

CHANGES

The tiny little building to the left (that you can't even really see) is the Calama airport I knew back in 2012-13. Now a two story airport, complete with jetways, restaurants, gift shops, and plenty more amenities towers next door.  From the mining town of Calama, we take a bus for about 1.5 hours to ALMA.

The control room (sala de control) has been switched around, so the antenna operators control the telescope from the far right corner, and workspaces are set up to the left of the entrance.

APPEARANCES

Big new project on the site: the residencia (hotel)!  This should include hotel rooms for employees and visitors, dining room, recreation facilities, and a swimming pool.  These already exist on the site (except for the swimming pool), but in the form of temporary modular buildings.

These guys seem to come and go over the years, but I think they have become much more friendly.  Here's one burro (donkey) greeting us at the door to the control building, and inspecting the hand of a co-worker.

DISAPPEARANCES

The camps where the antennas were being assembled by the European, Japanese, and North American teams are now nearly devoid of antennas, because nearly all (66 in total!) are at the "high site" and acting as reliable members of the array.  Here it appears that one lone antenna is being worked on by the Japanese (center).  The rest of the antennas are at 5000 meters elevation, whereas we work and operate the telescope array from 3000 meters.

Habemus ALMA!

Yesterday was a career-defining day for many people.  No, I'm not referring to the new Pope.  March 13th, 2013 marked the official inauguration of the ALMA observatory, a multi-national scientific collaboration many years in the making.  The inauguration event took place at the ALMA Operations Support Facility (OSF), located at an elevation of 3000 meters in the Atacama Desert of Northern Chile, where more than 500 people gathered, with the President of Chile, Sebastián Piñera as the guest of honor.  Joining President Piñera were representatives of ALMA’s international partners, foreign ambassadors, ALMA executives, ALMA personnel and representatives of the neighbouring communities.

Important guests at the inauguration, on one of the antenna transporters.
Photo credit: ESO

Although commissioning and science verification, as well as early science projects have been undertaken during the construction phase of ALMA, the inauguration event officially marks the transition to a fully-operating observatory.  While I wasn't one of the lucky few (hundreds of) people invited to the inauguration, I watched the video feed from the ALMA Santiago Central Offices, along with many of the ALMA employees responsible for various components of the observatory.  After about one hour waiting in anticipation for the President to arrive at the OSF and for the ceremony to begin, it was a festive environment in the conference room which typically hosts routine meetings or seminars.

Several speeches during the event reminded us of the complexity and longevity of the ALMA project (check out this video for the full story).  In fact, the observatory had been independently conceived as three separate projects by the Europeans, North Americans and Japanese in the 1980s.  Each cohort was hoping to access the best site in the world for radio astronomy, and investigate the southern skies at wavelengths that had previously been basically invisible to humans.  In the 1990s, the independent groups came together with an agreement to build the largest observatory in the world, something that no individual member could achieve on its own, considering the total construction cost of ALMA is more than a billion US dollars.  Construction began in 2003, and here we are in 2013 celebrating the observatory's inauguration!

You can find a brochure about the ALMA partnership here.

Some people at the inauguration have devoted their careers to this observatory, and they must be very proud, perhaps amazed, at what it has achieved, and what it will achieve during its expected operating lifetime of 30 years.  I should be very thankful to these people, because watching the inauguration, I also began to reflect on the role that ALMA has played in my own "career".  When I entered graduate school at Yale, I was interested in learning about astronomy as much as I was interested in learning about how to do astronomy.

The idea that what we know about star formation is limited by the capabilities of the most powerful telescope fascinated me, and I knew that ALMA would provide ground-breaking data in the coming years.  Equally fascinating to me was the idea that only via an international collaboration on the grandest scale could a sufficient telescope be constructed.  And, lucky for me, this observatory was being built in the Atacama Desert, a landscape which I already loved and to which I hoped to return.

My thesis has been exciting because I'm learning the capabilities of ALMA along with the majority of other astronomers, grad students and professors alike. I have been fortunate to be visiting ALMA during 2012-2013, to learn from the experts how ALMA operates, and to see as the first ALMA results are released.  This year we will have our own science project observed with ALMA, and we're eagerly awaiting answers to questions we have been asking for several years about our designated target.

We represent the ALMA partners: East Asia, Europe, North America and Chile
Photo credit: ESO/Max Alexander

I estimate that if my astronomy career dates back to 2008 with my first astronomy research project at Cerro Tololo, then ALMA-anticipation has occupied about 50-75% of my career.  It's not that I myself have been integral in the construction of ALMA, but rather that ALMA has been integral in the development of my own career.  I wonder if one day I will witness the inauguration of another major astronomical project like ALMA, but from the perspective of one of those who made it happen.

Not only the scientific results, but the economic and cultural components of astronomy keep me interested, and keep me traveling to observatories around the world, the majority in Chile.  We have a lot to learn about the Universe, and a lot to learn about people working together to make these discoveries possible.

On astronomy and international relations

Photo of James Bond filming at Paranal in 2008, photo courtesy of ESO.

It was in Chile that I first became passionate about astronomy in 2008. During the REU at Cerro Tololo Inter-American Observatory, we had an opportunity to visit several of the major observatories in Chile, including the European Southern Observatory (ESO) at Cerro Paranal, coincidentally just weeks before James Bond would be filmed at the observatory's residencia.  Astronomy in Chile was gaining world-wide notice, and at the same time I was contemplating what to do with a liberal arts major in physics, minor in economics and an interest in international relations.

My first visit to Paranal, learning about astronomy in Chile in 2008.
Behind me are some of the 1.8m ESO telescopes.

You probably know where this led me -- to pursue a PhD in Astronomy at Yale, Fulbright fellowship and year in Chile.  I find myself fortunate to follow a path which returns to the places where my passion began.  Recently I had the opportunity to travel to Paranal again, this time with several ALMA astronomers.  Our goal was to learn how Paranal operates and how ALMA might aspire to operate once the construction and commissioning are complete.  ALMA and Paranal are two great examples of international projects, based on a worldwide effort of scientists and governments working together, with the goal of investigating the physical secrets of our Universe.  In other words, physics, economics and international relations.

In 2012, I spent about 6 weeks at observatories, all the time observing light with wavelengths of about 1 mm, also called millimeter or sub-mm wavelengths, so my visit to Paranal was an opportunity to become re-acquainted with optical astronomy.  While the mm/sub-mm telescopes look like giant satellite dishes, the telescopes at Paranal use giant mirrors enclosed within domes.  Paranal has four 8.4 m telescopes called the Very Large Telescopes, as well as several 1.8 m telescopes, which can work together to comprise the Very Large Telescope Interferometer.  With an ESO scientist and interferometry expert, we toured the telescopes and interferometer lab, and we watched the scientists at work in the control room.  We asked a million questions about optical interferometry; of particular interest to us were comparisons with interferometry at longer wavelengths with ALMA.

An 8m mirror...

...inside one of these giant domes!

Paranal is run very efficiently, a joint-effort of astronomers, telescope operators, engineers, computer programmers, and other staff.  To give you some idea, there seemed to be about 10 astronomers and operators working in the control room at the beginning of the night, with decreased demand as the nights' observations progressed smoothly. During the day was time for engineers and programmers to maintain the equipment, or for astronomers to catch up on science projects.  We heard that it took years for many of these operations to be stream-lined following the construction of Paranal in XX, giving hope to the scientists at ALMA where construction only began a few years ago and inauguration is planned for March 2013.

Isolated from the nearest city of Antofagasta, about two hours by bus, the location of Paranal ensures very dark skies, and the facilities provide a very conducive work environment for the staff and visitors. The blast of humidity as you step into the residencia will rejuvenate your desert-dried skin, as the lush indoor greenery and swimming pool will also refresh your senses.  I was impressed by a photo exhibit featuring work by ESO astronomers, as well as professional artwork in the lobby. Small touches like these acknowledged that astronomers are people too.  For the creative, artistic or spiritual guests, there is also a music room, theater, gym and non-denominational chapel on site.  Three square meals a day at the cafeteria, and cookie cabinets in the control room, sustained the necessary scientific and extracurricular endeavors.

The residencia at Paranal, an oasis in the desert.

I only had the opportunity to spend one night at Paranal, but I enjoyed very much the first-hand account of how a major observatory operates.  A successful observatory seems to depend equally on human and technical capital.  Paranal certainly does have cutting edge telescopes, with multi-ton structures, perfectly polished mirrors and precise lasers.  To make all of this function, it also has trained personnel from many countries (in this case, mostly Europe and of course Chile), who are passionate about their work and their working environment.  ALMA is one degree more international, considering that ESO, which runs Paranal, is one of three partners, including North America and East Asia, in collaboration with Chile.  In the control room or cafeteria at these observatories, it's not uncommon to hear several languages, or to strike up conversations about careers and experiences around the world.

Although my day-job usually finds me staring at a computer screen in a more urban office environment, my experiences at observatories, often in foreign countries and among remarkable landscapes, remind me of the multi-faceted lure of astronomy, which I consider the greatest example of international relations and scientific endeavor.

How To: Observe with APEX

Something I find exciting, interesting about a thesis on observational astronomy is the experience to learn how to use a variety of telescopes, often in stunning locations.  One purpose of this blog is to document the diversity in observing experiences, since each telescope, location, team has a story to tell.

Getting ready for observations at APEX.

Last week at APEX, circumstances obliged me to take the role of operator and astronomer at the telescope, and I had the privilege and responsibility to learn and synthesize the observing techniques and requirements.  My informal training consisted of watching over the shoulder of a staff astronomer for a couple of days at the telescope, and then following remotely via a virtual network connection to the telescope during the morning shift preceding my afternoon shift.  I took note of important commands, and planned my strategy for the afternoon.

When the time came, so did the adrenaline, and to add to the excitement of observing, I was stunned when the first command I sent to the telescope by typing "go" triggered an alarm!  In fact, it was just a warning that the telescope was beginning to move, as intended, and the operations went ahead.

Over the next few days, I learned by experience the observing routine, the quirks of the system, and methods to make the job simpler.  The most valuable lessons which will help me in the future were the general observing routine, which might also interest you, so I'll describe it here.

In the control room at the telescope. Who knows what to do now?

Observing routine
An observing routine includes several general categories, including set-up, calibrations, and science targets.

Set-up
We need to tell the telescope where in the sky we want it to point, and what frequency to observe.  To test this, we point to an object we know well, for example a bright planet like Venus, and make a few observations called pointing and focus.  We run scripts that tell the telescope to scan across venus, and calculate the corrections in each direction we need to make to get the best signal.

Calibrations 
When we observe, we are essentially measuring the intensity of light that arrives to the telescope.  To tell anything physical about our target (in our case, the molecular gas of a star forming cloud), we need calibrations to measure all of the stray light that leaks into the signal between our detector and our target region XX light years away.

For the ambient light in the sky, we observe a point in the sky that we expect to be free of any light related to our target.  This is our "off position", and we will subtract this signal from our "science" target observations.

But wait, closer to home, we need to understand the signal from our electronics and the path the light takes within our telescope.  For this we measure the temperature of the system electronics.  So in reality our detection will be (target+sky+electronics) minus (sky) minus (electronics) equals just target.

If we don't have the set-up and calibrations done right, our science observations lose their physical meaning.  Sometimes we even spend more time on the previous than the latter.

Science
Ultimately, what excites us is the detection of radiation from the "science" target that we are studying.  We can study just one point in the sky and integrate for a really long time, or we can make a map by scanning over a larger region of the sky and observing each point for a shorter amount of time.

Etc.
APEX observes radiation with wavelengths called sub-mm, which are longer than visible wavelengths but shorter than radio.  A sub-mm telescope can operate 24 hours per day, observing different sources as they rise and set all day and all night.  We can only observe regions of the sky above the horizon but not directly over head, and also away from the sun or we will fry the telescope.  We need to make a detailed schedule of what is possible to observe and when.  As we observe, a source is either rising or setting, so we can only observe a given source for a limited time, in this case we generally stayed on a project for a few hours.

Ambient weather, such as wind and precipitation can damage the telescope, and at some point I noticed a flashing red box on the control screen notifying me that the wind gusts were exceeding 20 meters per second (45 mph).  Had this wind sustained, we would have stopped observing because this grad-student-turned-antenna-operator didn't want to be held responsible for the antenna blowing away.  The telescope is designed to sustain the extreme weather conditions of the Atacama, and in fact we had no problems.

In practice
The control system has been designed to relieve many of these concerns and simplify the observing procedure, at least in theory.  Scripts made by engineers or astronomers responsible for a particular project tell the telescope the sequence of calibrations and observations.  Blinking red lights on the control screen generally mean that something is not right, and a vigilant operator can catch a problem before it manifests.

Even so, the observer might think that the telescope is happily observing, when in fact for some reason a setting is not right.  During observations, it's good practice to take a quick look at data as they arrive and verify that the observations are what we expect.  Of course, we don't know the exact signal we expect, or we wouldn't need the observations in the first place, but we have a general idea of the frequency and intensity of radiation we hope to detect, and where in the sky to point the telescope. If we don't detect anything, we can do a thorough check of the system and perhaps re-calibrate.  By understanding the entire system and environment, from detector on the telescope to source in the sky, we can be more confident in the detections that we report as science.

Somewhat unrelated, but I think these are the coolest things at 5000 meters, the "penitentes" ice formations.

Chile-time at APEX

Hola from the Atacama Pathfinder Experiment (APEX) in the Atacama Desert of Northern Chile!  APEX is a telescope with a 12m antenna that detects sub-mm radiation, or somewhat higher frequency than radio waves.  Operated by institutions in Germany and Sweden, as well as the European Southern Observatory, the observatory also adheres to the agreement that Chilean astronomers can use the telescope 10% of the time during the year.  This week is "Chile-time"!  

The observations:
We're actually coming to the end of our observing run, and it has been a busy one.  After two days feeling slightly under the weather and trying to keep a cold at bay, then two more days preparing a proposal for APEX observations during the coming semester, finally the cold AND the proposal deadline have passed, and I'm getting the hang of the observations, making the experience extremely fulfilling academically.  In fact, I'm not observing my own project all the time, but rather a series of projects proposed by Chilean astronomers which are in the "queue", one of these being mine, and each day we choose which to observe next.  This is an efficient way to run an observatory, because the observatory can optimize lots of projects that each have distinct set-ups and requirements, such as time of day/night and weather conditions.

The other day, short-handed for telescope operators, I took command of the telescope during the afternoon shift and ran the queue of observations.  I wonder if this is the most expensive piece of equipment I have ever been responsible for, with the least amount of formal training?  Feeling a great sense of responsibility and also recognizing the value of this unique opportunity, in a couple of afternoons I have learned the basic observing routine, as well as synthesized a lot of what I had learned previously about observations of this kind.  In a coming post, I will try to explain more about how to observe with APEX.

Other "observations" along the way:
APEX is located on the same Chajnantor Plateau as ALMA, at an elevation of 5000 meters, and one exciting part of an observing run at APEX is ascending the ALMA road each afternoon to begin observations.  On the way, it's possible to "observe" incredible views and even rare wildlife, on the lucky days.  Giant birds, giant telescopes, giant mountains and deserts.  The experience has been awe-inspiring at many levels and at every moment.

My ALMA turno recap

The sun sets on my final flight from Calama.

Officially, my "visit" at ALMA is finished. I completed the agreed upon three months and three "turnos" (shifts at the ALMA site in northern Chile) in January through April, with a bonus fourth turno in late April.  The experience has been entirely positive, I have had an insider's view of what it takes the raise an observatory and to begin operations at the largest observatory in the world!  There are still many complicated aspects of the observatory that are beyond my understanding, but every day I learned something new that I hope will help me soon when I propose to use ALMA for observations related to my dissertation.

Following a wet "altiplanic winter", ALMA became rather green.

I value the opportunities I had to travel to northern Chile, and live for several weeks in the "driest desert in the world".  In fact, we experienced rain storms, snow, and sand storms in the early months this year.  Now it seems that the weather is improving, and we were able to make observations that are only possible in a few places on earth.

Equally interesting to me were the people I met who are part of this incredible international collaboration between North America, Europe and east Asia.  In the control room I often heard English, Spanish, and Japanese, which happen to be the three languages which I have learned (and I hope I have occasion to improve my Japanese again!), some sort of strange coincidence that leads me to believe that everything we do and learn will have some purpose in our lives in ways that we cannot foresee.

The sunset was always impressive from ALMA.  Check out the time sequence, especially where the sun is setting relative to the mountain in the distance.  In January...

Late February...

And finally the sunset in April.  The sun is now farther north, meaning summer is over and winter is soon.  For you in the northern hemisphere, summer is coming your way.

I hope to maintain my connections to ALMA during the remainder of my time in Chile, so now I'll be splitting time between the ALMA offices in Santiago and the Universidad de Chile Department of Astronomy.  During my final turno at ALMA, I asked a few of the people I had been working with (astronomers, data analysts, antenna operators) some questions about their jobs, to get a better idea of what it takes to work full time at an observatory like ALMA, realizing that one day I may be in a similar situation.  You can find their responses in my astrobites post here.

Science! In memory of Michele.

I sometimes wonder what is is that makes me love what I do.  And, when people ask me what is the point of studying the stars and the universe, it makes the stop and think. 

This sentence seems to explain it all: "Science is the greatest of all adventure stories, one that’s been unfolding for thousands of years as we have sought to understand ourselves and our surroundings."   Read more of the article here.

Note: I found this article from a link that was sent by my friend Michele.  Sadly, Michele passed away last year.  The MD project is a digital scrapbook created by her friends, where the memories of her live on.