It Takes a Team

There is no denying that the history we tell about science is full of achievements often credited to individual efforts.  The reality, of course, is that scientific achievements are not done alone or in intellectual vacuums.

Standing on the Shoulders of Giants

Astronomer Edwin Hubble, for example, built upon the ideas of other astronomers when he made his landmark discovery in 1923 that the faint spiral nebulae observed in the sky were actually other galaxies outside our Milky Way.  This surprising finding greatly expanded our understanding of the size of the universe.

Still from Hubblecast episode 89: Edwin Hubble

This is a still image from Hubblecast 89, which talks about the life of Edwin Hubble.  Credit: NASA & ESA

Before Hubble’s discovery, scientists were embroiled in a fierce debate about the nature of these nebulae.  Some, most prominently astronomer Harlow Shapley, believed that these nebulae were parts of our own Milky Way galaxy.  Others, like Heber Curtis, posited that the Milky Way galaxy was smaller than suggested by Harlow Shapley, and these nebulae were likely entire galaxies outside of the Milky Way.  This scientific disagreement was brought to the fore during a public debate between Curtis and Shapley in 1920.

It was not until 1923 when Edwin Hubble observed a cepheid variable star in one such nebulae that the debate was quickly settled.  Hubble determined that the cepheid variable he was observing was very far away – much too far away to be a part of the Milky Way galaxy.  In fact, he had discovered the variable star resided in what we now know to be our neighboring Andromeda galaxy.  This put to rest the debate vociferously argued by Shapley and Curtis.

Cepheid variable stars are stars whose intrinsic brightnesses change with time by a known amount. This makes them great “standard candles” to calculate their distances.  If you know you are observing a 60-watt light bulb, you can calculate the distance to the light bulb based on the amount of light you observe – the  fainter the 60-watt light bulb appears, the farther away it is.

The key to Hubble’s discovery was the knowledge that we could determine a cepheid variable’s intrinsic brightness based off of its observed periodicity, which is the amount of time the variable star takes to go from maximum brightness to minimum brightness and back to maximum brightness.  Hubble could not make his discovery without this background information, which, as it turns out, was first published in 1912 by astronomer Henrietta Swan Leavitt.  Henrietta was not given proper credit for this monumental discovery at the time, but there is now no doubt that her efforts paved the way for our modern understanding of stars and distances in the cosmos.

leavitt_aavso

Picture of astronomer Henrietta Swan Leavitt taken before 1921.

Astronomy, like all sciences, is dependent on building upon our scaffolded knowledge to further our understanding into new realms of the unknown.  It also depends upon teams of dedicated individuals working together.  Edwin Hubble, a premiere astronomer of the early 20th century, built upon the discoveries of prior scientists and engineers.  He also depended upon the support of his assistant and the staff of the Mt. Wilson Observatory, where he conducted many of his observations.

The Frontier Fields: A Team of Professionals Building Upon the Successes of Prior Programs

Today, astronomy is increasingly relying on larger projects that require teams of men and women with diverse skill sets, including the Hubble Frontier Fields program.  Frontier Fields was conceived following the successes of prior Hubble deep-field programs.  These include the Hubble Deep Field, Hubble Ultra Deep Field, CANDELS, and in particular, CLASH – which helped build our understanding of gravitational lensing around galaxy clusters.  The general Frontier Fields program also both benefited from, and enhanced, our understanding of mathematical models that predict how light from distant galaxies will be lensed by foreground massive clusters.  Of course, all of the deep-field studies are possible because of the work of prior luminaries such as Edwin Hubble, Henrietta Leavitt, and Albert Einstein.

In July 2016, the Hubble Frontier Fields team was given the AURA team award.  AURA – the Association of Universities for Research in Astronomy – operates the Space Telescope Science Institute (STScI – the science operations center for Hubble) for NASA.

"The STScI Frontier Fields team receives the 2016 AURA team award for its
unparalleled efforts in implementing the Hubble Frontier Fields Director's
Discretionary program and providing rapid [astronomical] community access to
high-level data products generated from the observations." - AURA

The full list of recipients of the AURA award can be found by clicking the link below.

hubble-frontier-fields-aura-award-recipients

2016 AURA Team  Award - STScI Frontier Fields

Some of the recipients of the 2016 AURA team award.  The team received the award in July 2016 for the Hubble Frontier Fields program, which began in 2013.  Credit: P. Jeffries/STScI.

In addition to the awardees, there is also support from the STScI directorate (Ken Sembach and Neill Reid).

It should be noted that the NASA Frontier Fields program is bigger than just the core Hubble Frontier Fields program at STScI.  There are also teams of people working with NASA’s other Great Observatories, the Chandra X-ray Observatory and the Spitzer Space Telescope, to acquire images of these fields in invisible X-ray and infrared light.  There are teams of astronomers proposing for follow-up observations of the Frontier Fields using many ground-based observatories in radio, millimeter, infrared, and visible light.  In addition, there are the astronomers and mathematical modelers who are taking this publicly available data and using it to broaden our understanding of the physics of the cosmos.

Science truly is a team sport.

The Whirlpool Galaxy Seen Through a Cosmic Lens

The Frontier Fields images, while beautiful, aren’t all that easy to comprehend to eyes outside the astronomy community. Look at them and you see streaks of light and blurry smudges mixed into a field of obvious galaxies. It can be difficult to interpret the distortions that occur as light from distant galaxies becomes magnified and bent by the vast mass of the Frontier Fields’ galactic clusters.

So here’s an interesting thought experiment. What if we could take a well-known galaxy and put it behind one of our Frontier Fields galaxy clusters? What would that look like?

Thanks to Dr. Rachael Livermore of the University of Texas at Austin and Dr. Frank Summers of the Space Telescope Science Institute, you can see for yourself. In this video simulation, the Whirlpool Galaxy, also known as M51, sweeps behind the Frontier Fields galaxy cluster Abell 2744. As it moves, the gravity of the galaxy cluster distorts the light of the Whirlpool, warping and magnifying and even multiplying its image.

Obviously, this isn’t a realistic video — galaxies don’t just take jaunts through the cosmos. But it illustrates how our image of the Whirlpool would change depending on where it was placed behind the galaxy cluster. Livermore used the Whirlpool Galaxy for this video because it’s a well-known, popular Hubble image, easily recognizable through the distortions that happen at different locations in the lensing cluster.

Take a look. After the intro, the image on the left of the dotted line shows the location of the Whirlpool behind the cluster, while the image on the right shows the lensing distortion underway.

In this simulation, we’ve moved the Whirlpool to a distance astronomers refer to as redshift 2. That far back, it would be so distant that the light we’re seeing from it would have started traveling away from the galaxy when the universe was just a quarter of its current age. If the Whirlpool were that far away in real life, its light would take 10 billion years to reach Earth.

Note that this isn’t how the Whirlpool would really appear at that distance. At such a distance, all we would be able to make out is the vivid central bulge of stars. But for the purpose of this illustration, the whole galaxy has been kept artificially bright.

The most impressive distortions occur as the Whirlpool passes behind the center of the galaxy cluster, with multiple, stretched, distorted images of the galaxy appearing. At this point, the light of the Whirlpool beaming toward Earth bends to go around the cluster, but can go either left or right. There’s no preference, so some of it goes one way, and some goes another, and we get many images of the same galaxy.

This location is ideal for astronomers, because as you can see in this illustration, the images become both stretched and magnified, allowing the galaxy structure to be seen in greater detail. Furthermore, because a gravitational lens acts much as a telescope lens, more light is focused our way, making the galaxies brighter.

This, Livermore notes, is a primary reason why astronomers are interested in these galaxy clusters – the chance to see the distant background galaxies in so much greater detail than Hubble would be able to produce on its own.

 

 

 

 

 

Spotlight on Gabriel Barnes Brammer, ESA/AURA Astronomer

This occasional series focuses on members of the Frontier Fields team. It highlights the individuals, their jobs, and the paths they took to get to where they are today.

Portrait of Gabriel Brammer

Astronomer Gabriel Brammer answers questions about his role on the Frontier Fields program and the path he took to get there.

What does a typical day on the job entail? What are your responsibilities?

A typical day involves a lot of communication: e-mail and teleconferencing with scientific collaborators around the U.S. and around the world, assisting observers with preparing their Hubble observations, and conversations and meetings with fellow members of the Hubble Wide Field Camera 3 instrument team. My research focuses on the formation and evolution of distant galaxies, often using Hubble observations. I have a position that allows me to pursue my own independent research interests along with my responsibilities supporting Hubble operations, and I appreciate that the goals of both of these aspects of my work are closely aligned.

 What specifically is your educational background?

I obtained a bachelor’s degree in astronomy from Williams College in Williamstown, Massachusetts, and a Ph.D. in astronomy from Yale University in New Haven, Connecticut.

 How did you first become interested in space?

My favorite subjects in school were always math and science, particularly physics when I was a bit older. Reading Carl Sagan’s “Cosmos” in high school always sticks with me as being a defining moment in inspiring my interest in space science and astronomy. Sagan presents such a clear connection between the beauty of the subject and the rigorous science that underlies it; I’ve seen from other profiles of my colleagues similar to this one that I’m far from alone in finding inspiration there!

Was there someone (parent, teacher, spouse, sibling, etc.) or something (book, TV show, lecture, etc.) that influenced you in developing a love for what you do, or the program you’re a part of?

The pursuit of an advanced degree in astronomy, or any field, is a very long chain that stretches over 20 years of a student’s life, obviously including a dramatic evolution in his or her own personal development and maturity. From day one I’m grateful for the tireless love, support, and encouragement from my parents and family, and I have had many excellent teachers, mentors, and role models at all stages of my education and career. Each of them represents a strong link in that chain, and without any one of them individually, the path I would have taken would likely have been very different from the one I am happy and honored to be on today.

Was there a particular event (e.g., lunar landing, first Shuttle flight, etc.) that particularly captured your imagination and led to life changes?

 The bright appearance of Comet Hale-Bopp in the winter of 1997, my junior year of high school, was a formative event for me at an opportune moment. Seeing the bright comet, a transient visitor from the outer solar system, just hanging over the horizon captivated me. As often as I could, I would drag the small telescope my dad had recently bought, along with as many friends I could muster, out to the cold, dark skies of central Iowa to see it.

Later in the summer of ’97, I went to New England to tour potential colleges, where, during a short visit to Williams College, I met Professor Jay M. Pasachoff and his students who were preparing an expedition to observe the solar eclipse in Aruba the following year. That brief encounter, along with the recent experience observing Hale-Bopp, showed me that studying astronomy would offer an ideal combination of research in the physical sciences and travel to exotic locales to observe both aesthetically and scientifically magnificent phenomena. I was privileged to later study and research with Professor Pasachoff myself, including an unforgettable expedition to observe the solar eclipse in Lusaka, Zambia, in 2001.

Gabe checks out the telescope for observations of the June 21, 2001, total solar eclipse from Lusaka, Zambia, as part of the Williams College Eclipse Expedition. Credit: J. Pasachoff.

Gabe checks out the telescope for observations of the June 21, 2001, total solar eclipse from Lusaka, Zambia, as part of the Williams College Eclipse Expedition. Credit: J. Pasachoff.

How did you first get started in the space business?

My first experience visiting and working at a professional astronomical observatory was with the National Science Foundation’s Research Experiences for Undergraduates program at the Cerro Tololo Inter-American Observatory in 2001. I must say I was pretty miserably exhausted my first night observing up on the mountain top, ready to adjust my career plans at 4 a.m., with the local radio reminding us between cumbia (dance music) hits of the glacial progress of time — “son las cuatro con cinco minutes … son las cuatro con diez minutos.” I suppose the second night was a bit better, and by the third night I was hooked.

I’ve been working at observatories ever since, now having spent something like 270 nights observing the skies from mountain tops in Arizona (Kitt Peak) and Chile (Cerros Tololo, Las Campanas, and Paranal) to valleys in Japan (Nobeyama). Going outside at night at one of these observatories and seeing the eyes of giant telescopes staring up at the sky, gathering in photons from distant objects, is an extraordinary experience. I’m happy to now have a more normal sleep schedule at the Space Telescope Science Institute, but I appreciate still being close to the day-to-day operations of Hubble as an observatory and working on the front lines as photons from distant stars and galaxies hit the detectors.

A composite image of sunset and midnight at the Very Large Telescope at Cerro Paranal, Chile.

A composite image of sunset and midnight at the Very Large Telescope at Cerro Paranal, Chile. Each of the four domes houses a telescope with a primary mirror 8.2 meters (26.9 feet) in diameter. Credit: Gabriel Brammer.

What do you think of the Hubble results, or the impact that Hubble has on society? 

Even classmates in my kids’ pre-kindergarten classes know Hubble when they see it! Hubble has something for everybody, from atmospheres of extra-solar planets to the most distant galaxies, and therefore has had an immeasurable impact on society’s scientific imagination and curiosity.

Is there a particular image or result that fascinates you?

To me the Hubble Ultra-Deep Field /eXtreme Deep Field (HUDF/XDF) represents all of the past success of Hubble and points to the future potential of Hubble and its successors like the James Webb Space Telescope in a single image. Now including near-infrared observations by the Wide Field Camera 3, installed in 2009, the HUDF/XDF shows us galaxies across some 95 percent of cosmic history, from the first star-bursting seeds of galaxies to the assembly of more massive, more regular structures of galaxies more like those we see today. The Frontier Fields represent the most recent exciting extension of the legacy begun with the Hubble Deep and Ultra-Deep Fields.

The eXtreme Deep Field, or XDF.

The eXtreme Deep Field, or XDF, was assembled by combining 10 years of NASA Hubble Space Telescope photographs taken of a patch of sky at the center of the original Hubble Ultra Deep Field. The XDF is a small fraction of the angular diameter of the full Moon. Credit: NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team.

 I also love browsing through Hubble’s spectacular high-resolution images of nearby galaxies. In the deep fields, we generally infer properties of galaxies based on small, barely resolved images of their structures, while images of local galaxies such as the mosaic of M82 show many of the myriad processes that form and shape galaxies in exquisite detail. It is through the combination of these resolved nearby studies and distant surveys that Hubble has made such a large contribution in our understanding of how galaxies form and evolve.

Mosaic image from Hubble of the magnificent starburst galaxy Messier 82 (M82).

This mosaic image from Hubble of the magnificent starburst galaxy Messier 82 (M82) is the sharpest wide-angle view ever obtained of this galaxy. M82 is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions. Credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA). Acknowledgment: J. Gallagher (University of Wisconsin), M. Mountain (STScI), and P. Puxley (National Science Foundation)

Are there specific parts of the program that you’re proud to have contributed to?

I am happy to have helped make the Frontier Fields observations as deep and as efficient as possible to maximize the scientific return from extremely valuable observing time on Hubble. With only a relatively minor change to the observing strategy, taking extra care to avoid extra glare from bright foreground light from the Earth, we enabled the Frontier Fields to see ever fainter and more distant galaxies than otherwise would have been possible.

Photo taken by Gabe of Comet Lovejoy (C/2011 W3) and the European Southern Observatory’s Very Large Telescope at Cerro Paranal, Chile (December 22, 2011). Credit: Gabriel Brammer.

Photo taken by Gabe of Comet Lovejoy (C/2011 W3) and the European Southern Observatory’s Very Large Telescope at Cerro Paranal, Chile (December 22, 2011). Credit: Gabriel Brammer.

 

Also see “Spotlight on Jennifer Mack, Research and Instrument Scientist,”
 Spotlight on Dan Coe, ESA/AURA Astronomer,” and Spotlight on Tricia Royle, Senior Program Coordinator.”

Spotlight on Tricia Royle, Senior Program Coordinator

This occasional series focuses on members of the Frontier Fields team.  It highlights the individuals, their jobs, and the paths they took to get to where they are today.

Portrait of Tricia Royle

Tricia Royle, senior program coordinator, answers questions about her role on the Frontier Fields program and the path she took to get there.

What does a typical day on the job entail? What are your responsibilities?

When astronomers are granted time on Hubble, their program is assigned to a program coordinator to make sure the observations are feasible and schedulable on the telescope. When problems occur any time between acceptance and execution, it’s the program coordinator who helps get problems resolved. We act as liaisons between the various groups at the Space Telescope Science Institute (STScI) — science, operations, scheduling — and the observers — principal investigators and co-investigators. I tend toward the large-scale and long-term observations like Frontier Fields.

What specifically is your educational background?

I have a BSc in physics and astronomy from York University in Toronto, Ontario, Canada, and I have taken postgraduate courses in applied physics from Johns Hopkins University in Baltimore, Maryland.

What particularly interested you in school or growing up?  What were your favorite subjects?

I wasn’t particularly good at school in the early years and didn’t like the monotony of memorizing multiplication tables or writing out spelling words. In grade six, when the curriculum started to get interesting and turn more logic-based, I started to pay attention and actually enjoyed just about every class — except history, which still had too much memory work. In high school, it became clear that math and science were my favorites, though I still took a lot of English and arts courses because I enjoyed the creativity involved.

Tricia Royle poses with an astronaut at Kennedy Space Center.

Nineteen-year-old Tricia on her fifth or sixth trip to Kennedy Space Center in Florida. Tricia recalls, “It was pretty much the first place I asked to go every time I’d go to Florida. Eventually, my family just accepted it as higher priority than Disney World.”

How did you first become interested in space?

Growing up in a very rural area about an hour outside of Toronto, surrounded by farms and no streetlights, I had always been able to see the Milky Way, but I didn’t know much about what I was seeing. When I first read that our sun was a star and figured out that meant every star I was seeing was potentially someone else’s “sun,” it was pretty humbling. I wasn’t very old and I’m pretty sure I annoyed a lot of aunts and uncles with my new-found “discovery” that our sun is actually a star. I didn’t understand how they could talk about anything else if they knew how many suns there were in the sky! Weather and gas prices just didn’t seem important enough to warrant discussion when compared to my new sun/star revelation.

Was there someone or something that influenced you in developing a love for what you do, or the program you’re a part of? Was there a particular event that especially captured your imagination and led to life changes?

A lot of things happened when I was in my pre-teens and teenage years to push me toward space. I remember feeling intense sadness and disbelief after the Challenger disaster. I was in middle school, just starting to enjoy learning, and had a hard time dealing with the idea that a teacher who was supposed to go into space, then come back to share her experience with her classroom and other classrooms, now wasn’t coming back at all. I hadn’t realized before then how dangerous it was to launch a shuttle and couldn’t see past the loss of those seven astronauts to understand why anyone would take that risk.

A year or so later, Star Trek: The Next Generation came on TV, and it all started to make sense. I loved the scientific language and ideas in the show and the notion of “going where no one had gone before.” Traveling around on the Enterprise seemed like a dream come true, and I started to understand why someone would put everything at risk to go into space. Star Trek: The Next Generation was my first exposure to positive science fiction — not just doomsday aliens and robots — and it introduced me to the concept of just how much more might be out there and what might be possible. Hubble launched a few years after that, when I was in high school, and started sending back incredible images of real things that were actually out there, waiting to be found. It seemed to me that maybe a bit of the show was coming to life and I wanted to know more.

When it came time to choose a topic for my first high school term paper — it happened to be advanced chemistry — I decided it was a good excuse to find out more about all those suns/stars I had seen in the sky as a child, on Star Trek for the past four or five seasons and now coming down from Hubble. This seemed like a really good idea until my 10-page report was closer to 30 pages, and I still had several books to go through. Thankfully, I had a wonderful chemistry teacher who encouraged me to delve as deep as I wanted into the topic, but to choose something specific to keep the final paper under 15 pages so she could finish reading it in an evening. I chose to focus on the life cycle of stars, and that was the beginning of my intense curiosity about the science of space and the universe.

Tricia Royle posing at the sign at the entrance to Kennedy Space Center.

On a later trip, 21-year-old Tricia poses at the entrance to Kennedy Space Center.

How did you first get started in the space business?

The summer after my third year at York University, I worked with Dr. John Caldwell analyzing Hubble data on the low-mass stellar companions of larger stars. During that summer, he visited STScI and Johns Hopkins University to attend a conference and meet with his collaborators. I was invited to tag along. I imagine I looked a little — or a lot — lost and awkward standing among seasoned Hubble scientists and STScI employees in the auditorium after a talk. Fortunately, one of the Hubble data analysts took pity on me and invited me into her conversation. Lisa Frattare — now part of Hubble Heritage — became an instant friend and would later encourage me to apply to work at STScI after graduation.

I didn’t take her seriously, thinking there was no way a fresh-out-of-school job could be with something as huge as Hubble. But on a dare with one of my college roommates, we both applied for our unattainable dream jobs — I applied to STScI and he applied for a coaching job at the University of Hawaii. As luck would have it, I got an interview and came to work at STScI shortly after graduation as a program coordinator. Sadly, my roommate did not make it out to Hawaii.

Before I left York University, Dr. Caldwell described my new position at STScI as “the hot seat of astronomy,” which ended up being an understatement. Immediately after I started, I was working with and attending conferences with scientists I’d seen listed in textbooks. In my first two years, I had the opportunity to work with the Director of STScI — Robert Williams — and many others on the Hubble Deep Field to push the science limits of the telescope, and to join Lisa Frattare and Keith Noll on the Hubble Heritage Project to help make beautiful images from Hubble’s scientific data. I worked with Hubble Heritage for five years and still think it is one of those really great initiatives that highlights for everyone, not just scientists, what Hubble can do. All in all, not a bad start to a career in space.

What do you think of the Hubble results, or the impact that Hubble has on society? 

 I think people have started to take for granted the amazing images Hubble continues to allow scientists to take. It’s been up there for almost 26 years, which means there are a lot of kids and even adults who don’t know what it’s like to NOT have these observations sent down on a regular basis, or what it was like before Hubble helped solve some of the fundamental questions about the expansion of the universe and what is out there. I have two school-aged kids who just assume that Hubble has or will answer any question they may have about stars or galaxies. I don’t think it occurs to them that Hubble hasn’t always been and won’t always be around to do that.

The fact that it is such an ingrained part of the scientific and academic community says just how successful it has become. It’s like the Internet – it’s hard to remember what it was like before we had this way to find answers to our questions. I suspect Hubble’s archives and legacy programs will continue to provide answers, or trigger new questions, for a long time yet.

Is there a particular image or result that fascinates you?

The Ultra Deep Field, or UDF. I found out I was pregnant with my first child just after I started working as program coordinator for the UDF, and the UDF images were released while I was still in the hospital after delivering my daughter — so I will forever tie those two events together. But more than that, I still use the UDF image in my presentations, even though it is almost 12 years old, because it fascinates everyone who learns what they are really looking at. I ask people to look at that image and realize that what they are seeing aren’t individual stars, but galaxies. Then I ask them to keep in mind that this particular piece of sky was chosen because it was “boring,” and to further consider that everything they are seeing is contained within a patch of sky the size of the president’s eye on a dime, held at arm’s length. More than a few jaws drop at the implication. Seeing the UDF image triggers that realization in people, especially kids, of just how vast the universe must be easily makes the UDF my favorite.

Are there specific parts of the program that you’re especially proud to have contributed to?

I like the view from where I sit in Operations. I like watching a Hubble program develop from the initial science outline in the Phase 1, to a workable Phase 2, to a successfully executed set of observations. I especially love the large and multi-cycle programs — 47 Tuc, Hubble Deep Field, Ultra Deep Field, Andromeda, CANDELS, and now Frontier Fields. They allow me to work with people who have such a passion for what they do on these in-depth programs and challenge me to find new ways to get them the science they need.

Because repeat observers are assigned, when possible, to the same program coordinator each time they observe, that working relationship has a chance to grow cycle after cycle. Program coordinators tend to get very attached to the scientists they work with multiple times. I’ve been here since Cycle 6 and now we’re ramping up for Cycle 24, so the list of observers I claim as mine is pretty long, and I feel very protective of them and their observations, even if they’ve moved on to other program coordinators or even other telescopes.

What outside interests could you share that would help others understand you better?

A lot of what we do on Hubble can feel abstract and intangible, since we can’t actually go to the telescope or out in space to touch what we observe — so I like to do things that produce more tangible, immediate results. In addition to my love of reading and watching sci-fi TV shows, I do a lot of crafts to create something I can hold in my hand.

With most of my observers scattered around the country and internationally, I rarely see them in person. Giving talks about Hubble to schools and the more general public lets me connect the science to people. Being able to explain a Hubble image to someone without a science background and make it real for them, helps put into perspective that what I do at work on a daily basis can be inspiring and has results beyond the image itself. I want what we do at STScI and on Hubble to show people they can dream as big as they like because the universe is big enough to handle it.

Is there anything else that you think is important for readers to know about you?

I was one of only four female physics and astronomy majors in my first year at York University. Before classes even started, my academic advisor suggested that I might want to choose something easier than physics and astronomy, despite coming in with an A+ average in high school and scoring in the top 5 percent on the math assessment. Male classmates with B averages were not given the same suggestion to find an easier major.

In the years ahead, every test grade of mine that fell below an A – there weren’t many – brought up the question from others, and myself, as to whether I really should be there, whether I was good enough. It was a constant fight to prove to classmates, professors and myself that I deserved to major in physics and astronomy. It wasn’t enough that I wanted to be there and was passing my courses – I had to excel. Four of us started, but I was the only female graduate in physics and astronomy in my year.

I have a daughter and a son, still relatively young, but they’re starting to look at what they want to do when they finish school. Obviously I want them to do well, but my wish for both of them, and anyone else looking at what to do in their life, is that in whatever field they choose, they know that wanting to be there is enough and they don’t have to prove to anyone they deserve to follow their dreams.

 

Also see “Spotlight on Jennifer Mack, Research and Instrument Scientist
and “
Spotlight on Dan Coe, ESA/AURA Astronomer

How Hubble “Sees” Gravity

[Note: this post is cross-posted on the Hubble’s Universe Unfiltered blog.]

Gravity is the familiar force of nature responsible for the diverse motions of a baseball thrown high into the air, a planet orbiting a star, or a star orbiting within a galaxy. Astronomers have long observed such motions and deduced the amount of gravity, and therefore the amount of matter, present in the planet, star, or galaxy. When taken to the extreme, gravity can also create some intriguing visual effects that are well suited to Hubble’s high-resolution observations.

Einstein’s general theory of relativity expresses how very large mass concentrations distort the space around them. Light passing through that distorted space is re-directed, and can produce a variety of interesting imagery. The bending of light by gravity is similar to the bending of light by a glass lens, hence we call this effect “gravitational lensing”.

einstein_cross_g2237_0305-hst-650x602

An “Einstein Cross” gravitational lens.

The simplest type of gravitational lensing is called “point source” lensing. There is a single concentration of matter at the center, such as the dense core of a galaxy. The light of a distant galaxy is re-directed around this core, often producing multiple images of the background galaxy (see the image above for an example). When the lensing approaches perfect symmetry, a complete or almost complete circle of light is produced, called an “Einstein ring”. Hubble observations have helped to greatly increase the number of Einstein rings known to astronomers.

a2218-hst-crop01-1280x768

Gravitational lensing in galaxy cluster Abell 2218

More complex gravitational lensing arises in observations of massive clusters of galaxies. While the distribution of matter in a galaxy cluster generally does have a center, it is never perfectly circularly symmetric and is usually significantly lumpy. Background galaxies are lensed by the cluster with their images often appearing as short thin “lensed arcs” around the outskirts of the cluster. Hubble’s images of galaxy clusters, such as Abell 2218 (above) and Abell 1689, showed the large number and detailed distribution of these lensed images throughout massive galaxy clusters.

These lensed images also act as probes of the matter distribution in the galaxy cluster. Astronomers can measure the motions of the galaxies within a cluster to determine the total amount of matter in the cluster. The result indicates that the most of the matter in a galaxy cluster is not in the visible galaxies, does not emit light, and is thus called “dark matter”. The distribution of lensed images reflects the distribution of all matter, both visible and dark. Hence, Hubble’s images of gravitational lensing have been used to create maps of dark matter in galaxy clusters.

In turn, a map of the matter in a galaxy cluster helps provide better understanding and analysis of the gravitational lensed images. A model of the matter distribution can help identify multiple images of the same galaxy or be used to predict where the most distant galaxies are likely to appear in a galaxy cluster image. Astronomers work back and forth between the gravitational lenses and the cluster matter distribution to improve our understanding of both.

macs_j0647_jd123-hst-montage-1100x805

Three lensed images of a distant galaxy seen through a cluster of galaxies.

On top of it all, gravitational lenses extend Hubble’s view deeper into the universe. Very distant galaxies are very faint. Gravitational lensing not only distorts the image of a background galaxy, it can also amplify its light. Looking through a lensing galaxy cluster, Hubble can see fainter and more distant galaxies than otherwise possible. The Frontier Fields project has examined multiple galaxy clusters, measured their lensing and matter distribution, and identified a collection of these most distant galaxies.

While the effects of normal gravity are measurable in the motions of objects, the effects of extreme gravity are visible in images of gravitational lensing. The diverse lensed images of crosses, rings, arcs, and more are both intriguing and informative. Gravitational lensing probes the distribution of matter in galaxies and clusters of galaxies, as well as enables observations of the distant universe. Hubble’s data will also provide a basis and guide for the future James Webb Space Telescope, whose infrared observations will push yet farther into the cosmos.

sdss_j1038+4849_smiley-hst-crop-500x420

A “smiley face” gravitational lens in a galaxy cluster.

The distorted imagery of gravitational lensing often is likened to the distorted reflections of funhouse mirrors, but don’t take that comparison too far. Hubble’s images of gravitational lensing provide a wide range of serious science.

‘Hubble’s Views of the Deep Universe’ – Public Lecture

On November 3, 2015, I gave a presentation called “Hubble’s Views of the Deep Universe”.  This presentation was to commemorate some of Hubble’s most influential observing campaigns during this 25th anniversary year.  Of course, I could not get to all of Hubble’s programs that observed the deep universe in just an hour.  For additional information, check out the science articles on the Hubble 25th website and, of course, keep checking back to this blog.

Dr. Brandon Lawton
“Hubble’s Views of the Deep Universe”

November 3, 2015

For two decades, the Hubble Space Telescope has pioneered the exploration of the distant universe with images known as the “deep fields”. These deep fields have given astronomers unprecedented access to understanding how galaxies form and develop over billions of years in the history of our universe, from shortly after the Big Bang to today. Join us for a retrospective view of Hubble’s contributions to the investigation of the deep reaches of the cosmos and some fresh glimpses of what Hubble is currently doing to further our understanding of the most distant parts of the universe.

This lecture is part of the monthly public lecture series at the Space Telescope Science Institute in Baltimore, Maryland. Each month addresses a different cosmic topic, usually related to Hubble, but always venturing to some fascinating part of the universe. For more information, check out the web page on HubbleSite:
http://hubblesite.org/about_us/public_talks/

Spotlight on Dan Coe, ESA/AURA Astronomer

This occasional series focuses on members of the Frontier Fields team.  It highlights the individuals, their jobs, and the paths they took to get to where they are today.

Dan Coe, ESA/AURA Astronomer, in front of the first Frontier Fields image, Abell 2744.

Dan Coe, ESA/AURA Astronomer, in front of the first Frontier Fields image, Abell 2744.

What is your position? What are your responsibilities?

I am an ESA/AURA astronomer at the Space Telescope Science Institute (STScI) in Baltimore. I use gravitational lensing to search for distant galaxies in Hubble and Spitzer Space Telescope images. I am the gravitational lens model coordinator for the Frontier Fields program. I also work to support astronomers’ use of Hubble’s Advanced Camera for Surveys and the Near-Infrared Camera on the upcoming James Webb Space Telescope.

How did you get involved with the Frontier Fields program?

In 2012, working on the Cluster Lensing And Supernova survey with Hubble (CLASH), I discovered a candidate for the most distant galaxy yet known, MACS0647-JD. Its light took about 13.4 billion years to get here, so we see it as it was long ago. We are looking 97 percent of the way back to the Big Bang. Back then, galaxies were much smaller, just 1 percent the size of our Milky Way, and had yet to form grand spiral structures.

MACS0647-JD is more distant than any of the galaxies discovered in the Hubble Ultra Deep Field (UDF), even though Hubble stared at the UDF for much longer: a week vs. four hours for the infrared images. This demonstrates the power of gravitational lensing. Galaxy clusters enable us to see fainter light from galaxies in the distant universe.

Gravitational lensing had been used often by astronomers, but its power had yet to be fully exploited. No one had taken ultra-deep images of a galaxy cluster with Hubble or Spitzer. I advocated for this to a committee convened by former STScI Director Matt Mountain. And now it has become a reality in the Frontier Fields program led by Jennifer Lotz. The ultra-deep images of galaxy clusters are revealing the faintest galaxies ever studied, magnified by gravitational lensing.

How do astronomers study gravitationally lensed galaxies?

The distant galaxies in these images are most typically magnified by factors of between 2 and 10. To properly study these galaxies, we need estimates of their magnifications from gravitational lens modeling. By studying the observed deflections and distortions of background galaxies, astronomers build up a model of each galaxy cluster’s mass distribution (primarily dark matter) and the resulting lensing magnifications.

For the Frontier Fields, five groups of astronomers from around the world collaborated to gather the best possible data on all six clusters and produce gravitational lensing models. I coordinated these efforts and processed their model submissions for all astronomers to use. This lens modeling work is unprecedented both for its collaborative nature and the accessibility that all astronomers now have to the magnification estimates. With deep Frontier Fields imaging now in hand, astronomers are able to study the lensing in much more detail and are producing the best dark matter maps and lensing models ever.

Are there specific parts of the program that you’re proud to have contributed to?

I helped Jennifer Lotz select the six Frontier Fields clusters—with a lot of input from other astronomers. I had hoped my babies would do well! So far they have, and I am proud.

Left: Frontier Fields Hubble image of Pandora's Cluster, Abell 2744. Right: Lensing magnifications (color) and distortions (swirls) of distant galaxies according to one model produced by Johan Richard and the

Left: Frontier Fields Hubble image of Pandora’s Cluster, Abell 2744. Right: Lensing magnifications (color) and distortions (swirls) of distant galaxies according to one model produced by Johan Richard and the “CATS” (Clusters As Telescopes) team.

How did you first become interested in space?

Mom was a space geek, as she tells it. She can still name the Mercury Seven [NASA’s first astronaut class]. She drew celestial bodies on the ceiling above my crib and hung a poster of Van Gogh’s “Starry Night” on my wall. She sat me on her lap to watch Carl Sagan’s “Cosmos” and to read the companion book. She took me outside to enjoy eclipses and meteor showers. And she held me in her arms and cried on my head as we watched the first Shuttle launch. I remember always being awestruck by the immensity of the universe. And I knew I wanted to work on everything.

This picture of Dan and his mom was taken when the future astronomer was just 5 months old.

This picture of Dan and his mom was taken when the future astronomer was just 5 months old.

What specifically is your educational background?

I went to Browne Academy elementary school, Thomas Jefferson High School for Science and Technology, Cornell University for my B.S. in Applied & Engineering Physics—with a concentration in astrophysics—and Johns Hopkins University, right across the street from STScI, for my Ph.D. in astronomy.

What particularly interested you in school or growing up? What were your favorite subjects?

Growing up, I loved math, puzzles, games, and eventually computer programming. The latter proved especially useful for my career since we write many programs to analyze our Hubble images and other data.

“What about poetry?” Mom would ask. She and my father had studied art, literature, and history. As a smart-aleck kid, I insisted all of that could be explained by mathematics. But as I grew up, I grew to appreciate the poetry in Carl Sagan’s explanations of our universe. I became more curious about all of the physical and personal forces that brought us to where we are and take us where we are going. And all of this, in time to meet my partner Kate Welch, a Shakespeare scholar, who gives me a deeper appreciation for both poetry and history. Turns out I should have listened to my mother all along!

How did you first get started in the space business?

I followed Carl Sagan to Cornell, but unfortunately I never got to meet him. He was too sick to teach my freshman year. During my senior year, astronomers announced new supernova results suggesting the existence of dark energy. Carl Sagan had taught us we are all made of star stuff. But then we learned that the universe is mostly made of something very different: dark matter and dark energy. Astronomy had humbled humanity yet again. I think I always planned to go to grad school for astronomy, but those exciting results really sealed it for me.

Once in grad school at Johns Hopkins, my advisor Narciso Benitez started me working on mapping dark matter in galaxy clusters by modeling gravitational lensing, and measuring distances to galaxies in new Hubble ACS images, including the UDF. He was a constant source of inspiration as I tackled tough analysis problems. I followed him to Granada, Spain, where I finished my Johns Hopkins Ph.D.

After three years at NASA’s Jet Propulsion Laboratory and Caltech in Pasadena, I am now back in Baltimore at STScI. My colleagues and I here are fortunate to work with Adam Riess, one of the Nobel Prize winners from that inspiring dark energy discovery in 1998.

What do you think of the Hubble results, or the impact that Hubble has on society?

I am proud to be contributing a small part to Hubble’s great legacy. In addition to my Frontier Fields work, I am leading a large new Hubble program called RELICS to observe 41 more lensing galaxy clusters. Complementary to the Frontier Fields, RELICS is casting a broader net with shallower imaging. Our goal is to find the best and brightest distant galaxy candidates for more detailed study with current telescopes and with the James Webb Space Telescope.

Hubble has filled us with wonder and taken us back in time, almost all the way back to the Big Bang. By flipping through Hubble’s scrapbook, we can relive 97 percent of the history of the universe. James Webb will tell the tale of our cosmic origins in the first galaxies.

I can’t say I really comprehend the immensity of the universe any more than I did as a child. But I have appreciated new details, and I remain awestruck. The universe teaches us to be humble yet proud, and most of all, I think, grateful. Humble, as an insignificant speck in the vast cosmos. Proud that we have come so far and can begin to comprehend it. And grateful that we have the privilege to witness and explore so much of it.

Is there a particular image or result that fascinates you?

We named one of our cats after the Carina Nebula. The Hubble + CTIO Blanco color image of this stellar nursery is a masterpiece—the most beautiful astronomy image I’ve seen. Our other cat is named Maggie, after Queen Margaret in Shakespeare’s Henry VI; she has a “tiger’s hide.”

Dan calls picture of the Carina Nebula

Dan calls this picture of the Carina Nebula “the most beautiful astronomy image I’ve seen.” This 50-light-year-wide view of the nebula’s central region shows a maelstrom of star birth and death. The mosaic was assembled from 48 frames taken with Hubble’s Advanced Camera for Surveys, with information added from the Cerro Tololo Inter-American Observatory in Chile.

What outside interests—e.g., hobbies, service, dreams, activities—could you share that would help others understand you better?

When I was around 10, my father and I started playing duplicate bridge at a local club on Saturdays. Many of the other partnerships would argue with one another over their play, but not us. Dad and I did our best, celebrated our good plays, and learned from our mistakes, but never got angry with one another. My parents’ unwavering support, pride, encouragement, and engagement of my curiosity have made me the astronomer I am today. I do my best to keep making them proud.

Dan, at the age of 11, poses with his mom and dad.

Dan, at the age of 11, poses with his dad and mom.

Is there anything else that you think is important for readers to know about you?

I feel very fortunate to be paid to do what I love. And I have been privileged. Like many others at STScI, I work hard and try to give back in small part by sharing the rich history of our universe with others in Baltimore and with people around the world. I hope you enjoy hearing our stories.

Also see “Spotlight on Jennifer Mack, Research and Instrument Scientist.”

Spotlight on Jennifer Mack, Research and Instrument Scientist

This occasional series focuses on members of the Frontier Fields team.  It highlights the individuals, their jobs, and the paths they took to get to where they are today.   

This is a picture of Jennifer Mack, a Hubble Research and Instrument Scientist.

Jennifer Mack, a Hubble Research and Instrument Scientist, answers questions about her role on the Frontier Fields project.

What is your position?

My formal title is Research & Instrument Scientist in Hubble Space Telescope’s Instruments Division. I help manage the Frontier Fields data pipeline, which delivers the best possible calibrated data products to the astronomical community. I am also part of the WFC3 [Wide Field Camera 3] Instrument team where I work on calibration of the UVIS [ultraviolet and visible light] and IR [infrared light] detectors.

What is a “data pipeline” and what does it mean to “calibrate”?

A data pipeline is a set of software for processing and combining sets of images. It includes tools to correct for instrument artifacts, such as bad pixels, thermal signal from the detectors, and variations in sensitivity across the field of view. The goal of calibration is to tie the brightness of objects measured in Hubble’s cameras to some absolute system, based on measurements of stars of known brightness.

What does a typical day on the job entail? What are your responsibilities?

The data pipeline team keeps an eye on the Frontier Fields images as they are arriving from the telescope. For a given cluster, these come in a steady stream over a period of about 6 weeks, so we have to keep on top of things. First and foremost we need to be sure that the telescope was pointing in the right place and that it was stable throughout the exposure.

We also develop software to correct the images for artifacts that aren’t automatically handled by Hubble’s standard calibration pipeline. This includes masking out artifacts like satellite trails or scattered light from bright stars. We also mask IR ‘persistence’ which is leftover signal from very bright objects in observations taken just prior to ours. For the IR detector, we correct the images for stray light, usually from the bright Earth, that varies with time over the course of an exposure. For the ACS [Advanced Camera for Surveys] detector, we correct for artifacts like hot pixels and charge transfer losses during readout, both of which are considerable after being in space for 13 years.

Once that is complete, we correct the images for distortion and align them. These are then stacked together to create full-depth mosaics for each filter using specialized software called AstroDrizzle which allows us to optimize the resolution of the final images.

What specifically is your background?

I have a BS in physics and an MS in astrophysics. I’ve been at Space Telescope since 1996, and over the years have helped calibrate Hubble’s main imaging cameras: WFPC2 [Wide-Field Planetary Camera 2], ACS, and now WFC3.

What particularly interested you in school or growing up?  What were your favorite subjects?

I was particularly interested in science and math in high school. I remember in physics class we had to predict the landing spot of a marble rolled down an inclined plane and off of the side of a table. Measuring only the height of the incline, the height of the table, and the time the marble was in the air, we were able to calculate where on the floor the marble would land and then put a paper cup there to catch it. I was amazed that this actually worked and was struck by the power of mathematics to predict events which seemed like magic to me.

How did you first become interested in space?

My birthday coincides with the peak of the Perseid meteor shower. This is a particularly spectacular event in southwest Colorado where I grew up, and when I was little I asked my mom if the meteors were special for my birthday. She cleverly told me that they must be, and that felt very magical to me. When I got older, friends and I would hike to the top of a mountain and lay back to get a full view of the night sky. As the meteors streaked across the sky, we would imagine that we were clinging to the side of the Earth, spinning at 1000 miles/hour, and trying not float away into space. Growing up under really dark skies really sparked my curiosity about space and made me think about all the mysteries still undiscovered.

Was there someone (parent, teacher, spouse, sibling, etc.) or something (book, TV show, lecture etc.) that influenced you in developing a love for what you do, or the program you’re a part of?

When I was young, I asked a lot of questions and especially wanted to understand how and why things worked. My parents never said “I don’t know,” but took the time to show me how to find answers, either in books or on the computer. We watched a lot of nature documentaries together, including the original Cosmos series which resulted in a lot of interesting discussions. My parents really listened to my questions and as a result instilled in me a general curiosity and love of learning.

Is there a particular image or result that especially fascinates you?

I’ve always been fascinated by galaxy clusters, and the Frontier Fields images are pushing the limits of HST’s instruments to the extreme. By combining very deep exposures with the power of a gravitational lens, we are able to look back even further in time to view galaxies when the Universe was only 500 million years old. When you create very deep images like these, limitations in the current instrument calibration become apparent. We are developing new techniques to do cutting-edge calibration and sharing these new methods with the user community in the hope of allowing for the best possible science with HST. It’s exciting to be a part of all this new discovery!

Are there specific parts of the program that you’re particularly proud to have contributed to?

In addition to my Frontier Fields work, I’m proud to be a member of the Hubble Heritage Team, which produces some of the most iconic astronomy images ever. These images are designed specifically for the purpose of inspiring people, and I think that is an especially worthy pursuit! My specialty is in understanding Hubble’s instruments, and I work on designing the observations and also in calibrating and aligning the images once they have been acquired. Some recent mosaics I’ve had the pleasure of working on include hits like the Eagle Nebula, Westerlund 2, the Monkey Head Nebula, and the Horsehead Nebula.

Is there anything else that you think is important for readers to know about you?

I have a 5-year-old son who loves space and especially playing Lego “Hubble Rescue” to reenact the servicing missions. One of his more memorable quotes: “Hey mom, how about this time I be Mike Massimino and you be John Grunsfeld!” Being able to share my passion for astronomy with my son has been especially rewarding. [Editor’s note: Mike Massimino performed spacewalks on two Hubble servicing missions, and John Grunsfeld is a spacewalking veteran of three Hubble servicing missions.]

This picture shows Jennifer Mack enjoying time  with her son in a field in Colorado.

Jennifer Mack enjoying time in Colorado with her son.

 For more information on the processing of Hubble images, please see these posts:

For more information on how Hubble images are proposed, planned, and scheduled, please see these posts:

Galaxy Shapes in the Frontier Fields Observations

We can learn a lot about galaxies by analyzing their light, through computer modeling, and using other complex techniques. But at the most basic level, we can learn about galaxies by studying their shapes.

Galaxy appearance immediately reveals certain characteristics. Elliptical galaxies contain a wealth of old stars. Spiral galaxies are full of gas and dust. Distorted galaxies have likely experienced a gravitational interaction with another galaxy that warped their structure.

The Mice, as these colliding galaxies are called, are a pair of spiral galaxies seen about 160 million years after their closest encounter. Gravity has drawn stars and gas out of the galaxies into long tails.  Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA

The Mice, as these distorted colliding galaxies are called, are a pair of spiral galaxies seen about 160 million years after their closest encounter. Gravity has drawn stars and gas out of the galaxies into long tails. Credit: NASA, H. Ford (JHU), G. Illingworth (UCSC/LO), M.Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA

The Frontier Fields project adds another dimension to this simple analysis. When we look at extremely distant galaxies with the magnification of gravitational lensing, we see new detail that was previously obscured by distance. Their shapes are clues to what occurred within those galaxies when they were very young.

Galaxies viewed through the gravitational lenses of the Frontier Fields clusters can be seen at a resolution 10 times greater than non-lensed galaxies. That means those tiny red dots that so thrill astronomers in normal Hubble images actually have some structure in Frontier Fields imagery.

Previous studies, such as the Hubble Ultra Deep Field, The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, or even adaptive optics-enhanced studies by ground telescopes have shown that young, star-forming galaxies at about a redshift of 2 (existing when the universe was about 3.3 billion years old) appear to have a certain lumpiness. But without gravitational lensing, we lack the resolution to say for sure whether those lumps were massive clusters of newly forming stars, or whether some other factor was causing those galaxies to have a clumpy appearance.

Frontier Fields has revealed that yes, many of those galaxies have star-forming knots that really are quite large, implying that star formation occurred in a very different way in the early universe, perhaps involving greater quantities of gas in those young galaxies than previously expected.

Frontier Fields has also given us a better grasp of the physical size of gravitationally lensed young galaxies even farther away, at a redshift of 9 (when the universe was around 500 million years old). Observations show that these galaxies are actually quite small – perhaps 200 parsecs across, while a typical galaxy you see today is closer to 10,000 parsecs across. These observations help plan future observations with the Webb Space Telescope, picking out what will hopefully be the best targets for study.

This composite image shows examples of galaxies similar to our Milky Way at various stages of construction over a time span of 11 billion years. The galaxies are arranged according to time. Those on the left reside nearby; those at far right existed when the cosmos was about 2 billion years old. The Frontier Fields project is collecting galaxies from the earliest epochs of the universe to add to such comparisons. Credit: NASA, ESA, P. van Dokkum (Yale University), S. Patel (Leiden University), and the 3D-HST Team

This composite image shows examples of galaxies similar to our Milky Way at various stages of construction over a time span of 11 billion years. The galaxies are arranged according to time. Those on the left reside nearby; those at far right existed when the cosmos was about 2 billion years old. The Frontier Fields project is collecting galaxies from the earliest epochs of the universe to add to such comparisons. Credit: NASA, ESA, P. van Dokkum (Yale University), S. Patel (Leiden University), and the 3D-HST Team

Galaxy shape also plays a role in discoveries in the Frontier Fields’ six parallel fields, which are unaffected by gravitational lensing but provide a view into space almost as deep as Hubble’s famous Ultra Deep Field, with three times the area.

It’s well known that galaxies collide and interact, drawn to one another by gravity. Most galaxies in the universe are thought to have gone through the merger process in the early universe, but the importance of this process is an open question. The transitional period during which galaxies are interacting and merging is relatively short, making it difficult to capture. A distant galaxy may appear clumpy and distorted, but is its appearance due to a merger – or is it just a clumpy galaxy?

Collision-related features — such as tails of stars and gas drawn out into space by gravity, or shells around elliptical galaxies that occur when stars get locked into certain orbits – are excellent indicators of merging galaxies but are hard to detect in distant galaxies with ordinary observations. Frontier Fields’ parallel fields are providing astronomers with a collection of faraway galaxies with these collision-related features, allowing astronomers to learn more about how these mergers affected the galaxies we see today.

As time goes on and the cluster and parallel Frontier Fields are explored in depth by astronomers, we expect to to learn much more about how galaxy evolution and galaxy shapes intertwine. New results are on the way.

The Incredible Time Machine

Today’s guest post is by Mary Estacion. Mary is the News Video Producer at the Space Telescope Science Institute. She is also the host and producer of the “Behind the Webb” podcast series, which showcases the James Webb Space Telescope as it is being built as well as the engineers and scientists working on the observatory. The video in this post highlights a topic of particular interest to the Frontier Fields project — deep field astronomy.

The production of the “The Incredible Time Machine” video is part of a year-long celebration highlighting 25 years of the Hubble Space Telescope. Because of Hubble, we can see back to hundreds of millions of years after the Big Bang. This particular segment includes more than a half a dozen scientists from all over the country who have used Hubble to look at the universe’s earliest days. It takes you through the history of the Deep Field Program and shows how the addition of new instruments on Hubble throughout the years has furthered our understanding of the universe’s evolution.

For the video, go here:  http://hubble25th.org/video/5