Members Can Post Anonymously On This Site
Post-flight interview with Matthias Maurer | Cosmic Kiss
-
Similar Topics
-
By NASA
This artist’s concept shows how the universe might have looked when it was less than a billion years old, about 7 percent of its current age. Star formation voraciously consumed primordial hydrogen, churning out myriad stars at an unprecedented rate. NASA’s Nancy Grace Roman Space Telescope will peer back to the universe’s early stages to understand how it transitioned from being opaque to the brilliant starscape we see today.NASA, ESA, and A. Schaller (for STScI) 0:00 / 0:00
Your browser does not support the audio element. Today, enormous stretches of space are crystal clear, but that wasn’t always the case. During its infancy, the universe was filled with a “fog” that made it opaque, cloaking the first stars and galaxies. NASA’s upcoming Nancy Grace Roman Space Telescope will probe the universe’s subsequent transition to the brilliant starscape we see today –– an era known as cosmic dawn.
“Something very fundamental about the nature of the universe changed during this time,” said Michelle Thaller, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Thanks to Roman’s large, sharp infrared view, we may finally figure out what happened during a critical cosmic turning point.”
Lights Out, Lights On
Shortly after its birth, the cosmos was a blistering sea of particles and radiation. As the universe expanded and cooled, positively charged protons were able to capture negatively charged electrons to form neutral atoms (mostly hydrogen, plus some helium). That was great news for the stars and galaxies the atoms would ultimately become, but bad news for light!
It likely took a long time for the gaseous hydrogen and helium to coalesce into stars, which then gravitated together to form the first galaxies. But even when stars began to shine, their light couldn’t travel very far before striking and being absorbed by neutral atoms. This period, known as the cosmic dark ages, lasted from around 380,000 to 200 million years after the big bang.
Then the fog slowly lifted as more and more neutral atoms broke apart over the next several hundred million years: a period called the cosmic dawn.
“We’re very curious about how the process happened,” said Aaron Yung, a Giacconi Fellow at the Space Telescope Science Institute in Baltimore, who is helping plan Roman’s early universe observations. “Roman’s large, crisp view of deep space will help us weigh different explanations.”
0:00 / 0:00
Your browser does not support the audio element. Prime Suspects
It could be that early galaxies may be largely to blame for the energetic light that broke up the neutral atoms. The first black holes may have played a role, too. Roman will look far and wide to examine both possible culprits.
“Roman will excel at finding the building blocks of cosmic structures like galaxy clusters that later form,” said Takahiro Morishita, an assistant scientist at Caltech/IPAC in Pasadena, California, who has studied cosmic dawn. “It will quickly identify the densest regions, where more ‘fog’ is being cleared, making Roman a key mission to probe early galaxy evolution and the cosmic dawn.”
The earliest stars were likely starkly different from modern ones. When gravity began pulling material together, the universe was very dense. Stars probably grew hundreds or thousands of times more massive than the Sun and emitted lots of high-energy radiation. Gravity huddled up the young stars to form galaxies, and their cumulative blasting may have once again stripped electrons from protons in bubbles of space around them.
“You could call it the party at the beginning of the universe,” Thaller said. “We’ve never seen the birth of the very first stars and galaxies, but it must have been spectacular!”
But these heavyweight stars were short-lived. Scientists think they quickly collapsed, leaving behind black holes –– objects with such extreme gravity that not even light can escape their clutches. Since the young universe was also smaller because it hadn’t been expanding very long, hordes of those black holes could have merged to form even bigger ones –– up to millions or even billions of times the Sun’s mass.
Supermassive black holes may have helped clear the hydrogen fog that permeated the early universe. Hot material swirling around black holes at the bright centers of active galaxies, called quasars, prior to falling in can generate extreme temperatures and send off huge, bright jets of intense radiation. The jets can extend for hundreds of thousands of light-years, ripping the electrons from any atom in their path.
NASA’s James Webb Space Telescope is also exploring cosmic dawn, using its narrower but deeper view to study the early universe. By coupling Webb’s observations with Roman’s, scientists will generate a much more complete picture of this era.
So far, Webb is finding more quasars than anticipated given their expected rarity and Webb’s small field of view. Roman’s zoomed-out view will help astronomers understand what’s going on by seeing how common quasars truly are, likely finding tens of thousands compared to the handful Webb may find.
This view from the James Webb Space Telescope contains more than 20,000 galaxies. Researchers analyzed 117 galaxies that all existed approximately 900 million years after the big bang. They focused on 59 galaxies that lie in front of quasar J0100+2802, an active supermassive black hole that acts like a beacon, located at the center of the image above appearing tiny and pink with six prominent diffraction spikes. The team studied both the galaxies themselves and the illuminated gas surrounding them, which was lit up by the quasar’s bright light. The observation sheds light on how early galaxies cleared the “fog” around them, eventually leading to today’s clear and expansive views.NASA, ESA, CSA, Simon Lilly (ETH Zürich), Daichi Kashino (Nagoya University), Jorryt Matthee (ETH Zürich), Christina Eilers (MIT), Rob Simcoe (MIT), Rongmon Bordoloi (NCSU), Ruari Mackenzie (ETH Zürich); Image Processing: Alyssa Pagan (STScI), Ruari Macken “With a stronger statistical sample, astronomers will be able to test a wide range of theories inspired by Webb observations,” Yung said.
Peering back into the universe’s first few hundred million years with Roman’s wide-eyed view will also help scientists determine whether a certain type of galaxy (such as more massive ones) played a larger role in clearing the fog.
“It could be that young galaxies kicked off the process, and then quasars finished the job,” Yung said. Seeing the size of the bubbles carved out of the fog will give scientists a major clue. “Galaxies would create huge clusters of bubbles around them, while quasars would create large, spherical ones. We need a big field of view like Roman’s to measure their extent, since in either case they’re likely up to millions of light-years wide –– often larger than Webb’s field of view.”
Roman will work hand-in-hand with Webb to offer clues about how galaxies formed from the primordial gas that once filled the universe, and how their central supermassive black holes influenced galaxy and star formation. The observations will help uncover the cosmic daybreakers that illuminated our universe and ultimately made life on Earth possible.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory and Caltech/IPAC in Southern California, the Space Telescope Science Institute in Baltimore, and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.
Download high-resolution video and images from NASA’s Scientific Visualization Studio
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media contact:
Claire Andreoli
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
Explore More
5 min read How NASA’s Roman Space Telescope Will Rewind the Universe
Article 1 year ago 6 min read How NASA’s Roman Space Telescope Will Chronicle the Active Cosmos
Article 8 months ago 5 min read How NASA’s Roman Mission Will Hunt for Primordial Black Holes
Article 3 months ago Share
Details
Last Updated Jul 25, 2024 ContactAshley Balzerashley.m.balzer@nasa.govLocationGoddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Active Galaxies Astrophysics Black Holes Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research Goddard Space Flight Center James Webb Space Telescope (JWST) Origin & Evolution of the Universe Science & Research Stars Supermassive Black Holes The Big Bang The Universe View the full article
-
By NASA
Rebekah Hounsell is an assistant research scientist working on ways to optimize and build infrastructure for future observations made by the Nancy Grace Roman Space Telescope. The mission will shed light on many astrophysics topics, like dark energy, which are currently shrouded in mystery. Rebekah also works as a support scientist for the TESS (Transiting Exoplanet Survey Satellite) mission, helping scientists access and analyze data.
Name: Rebekah Hounsell
Title: Assistant Research Scientist
Formal Job Classification: Support Scientist for the TESS mission and Co-Principal Investigator of the Roman Supernova Project Infrastructure Team (PIT)
Organization: Code 667.0
Rebekah Hounsell knew she wanted to study space from a very young age. Now, she’s a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md. NASA/Chris Gunn What do you do and what is most interesting about your role at Goddard?
I am fortunate to have several roles at Goddard. I am a support scientist for TESS. Here I aid the community in accessing and analyzing TESS data. I am a co-principal investigator of a Roman project infrastructure team, focusing on building infrastructure to support supernova cosmology with the Roman HLTDS (High Latitude Time-Domain Survey). In addition, I am part of the Physics of the Cosmos program analysis group executive committee, co-chairing both the Cosmic Structure Science interest group and the Time-Domain and Multi-Messenger Astrophysics Science interest group. In these roles I have been fortunate enough to get a glimpse into how missions such as TESS and Roman work and how we can make them a success for the community. Missions like TESS are paving the way for future wide area surveys like Roman, providing a plethora of high cadence transient and variable star data, which can be used to gain a better understanding of our universe and our place within it.
How will your current work influence the Nancy Grace Roman Space Telescope’s future observations?
The Roman team I am leading is tasked with developing a pixels-to-cosmology pipeline for the analysis of supernova data from the HLTDS. What this means is that we will develop tools to aid the community in obtaining supernova lightcurves and prism spectra, which are precise enough to be used in testing various cosmological modes. We are also working to develop tools which will allow the community to test various HLTDS designs, adjusting cadence, filters, exposure times, etc., to best optimize its output for their science.
What got you interested in astrophysics? What was your path to your current role?
When I was a child I lived in a very rural area in England, with little to no light pollution. I had a wonderful view of the night sky and was fascinated by stars. I remember when I found out that the universe was expanding and my first thought was “into what?” I think it was that which fueled my curiosity about space and pushed me into astrophysics. At about 10 years old, I decided astrophysics was the path for me, and after that I really started to focus on physics and math at school.
At 18, 19 I went to Liverpool University/Liverpool John Moores and completed my master’s in astrophysics in 2008. I then went on to obtain my Ph.D., focusing on classical and recurrent novae. In 2012 I received my first postdoc at STScI (the Space Telescope Science Institute in Baltimore). It was at STScI that I learned about how the instruments operating on Hubble worked and figured out that what I really loved doing was working on data and improving it. At the time however, I wasn’t ready to leave academia altogether, so I took another postdoc at the University of Illinois Champaign Urbana/UC Santa Cruz. It was here that I first started working on Roman, only back then it was known as WFIRST. I was a member of a Supernova Science Investigation Team for WFIRST and worked to optimize the design of what was then known as the SN survey, later to become the HLTDS. During this time I published a paper that created some of the most realistic simulations of the survey, including various statistical and systematic effects. After this I headed to the University of Pennsylvania to work on core collapse supernovae from the Dark Energy Survey. This was an exciting data set, but again I realized what I really liked doing was working on data from or for a mission. As such I took my current job at NASA.
Rebekah stands by a model of NASA’s upcoming Nancy Grace Roman Space Telescope. The observatory’s deployable aperture cover, or sun shade, is visible in the background in the largest clean room at Goddard.NASA/David Friedlander What are you most looking forward to exploring through Roman’s eyes?
Given the nature of the mission, Roman is going to discover a plethora of transient events. Some of these will be extremely rare and if caught in one of Roman’s high cadenced, deep fields, the data obtained will be able to shed new light on the physics driving these phenomena. I am also excited about these data being used with those from other observatories including the Vera C. Rubin Observatory and NASA’s James Webb Space Telescope.
What has surprised you the most about the universe as you’ve learned more about it?
We are still discovering so many new things which shed new light on the universe, its evolution, and our place in it. In recent years we have learned about kilonovae, gravitational waves, and we’ve discovered various diverse supernovae. There are so many extreme and complex events that we are still trying to understand, and I suspect that Roman will reveal even more.
What is your favorite thing about working for NASA?
There is no one path to working at NASA. I have met so many people who entered into the field following completely different paths than myself. I love this. We all have something different to bring to the table and those differences are what makes NASA what it is today.
A portrait of Rebekah in front of the NASA meatball.NASA/David Friedlander What hobbies fill your time outside of work?
I like to paint and draw. I also enjoy looking after animals. I also love participating in outreach events. When I lived in Philly I helped to set up the Astronomy on Tap branch there. I think it is important to talk about what we do and why it is needed.
What advice do you have for others who are interested in working in astronomy?
There is no one path. Don’t think you have to complete x, y, z steps and then you make it. That is not true. Do what you are passionate about, what you enjoy to learn about. And most importantly ask questions! Learn about what others are doing in the field, how they got there, and figure out what works for you.
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Conversations With Goddard is a collection of Q&A profiles highlighting the breadth and depth of NASA’s Goddard Space Flight Center’s talented and diverse workforce. The Conversations have been published twice a month on average since May 2011. Read past editions on Goddard’s “Our People” webpage.
Share
Details
Last Updated Jul 16, 2024 ContactAshley Balzerashley.m.balzer@nasa.govLocationGoddard Space Flight Center Related Terms
People of NASA Careers Goddard Space Flight Center Nancy Grace Roman Space Telescope People of Goddard Women at NASA Explore More
10 min read Ken Carpenter: Ensuring Top-Tier Science from Moon to Stars
Article 2 months ago 8 min read Joshua Schlieder: Feet on the Ground, Head in the Stars
Goddard astrophysicist Dr. Joshua Schlieder supports NASA's Roman Space Telescope and Swift Observatory with creativity,…
Article 6 months ago 8 min read Melissa Vess: Triathlete and Roman Spacecraft Systems Engineer
Article 3 years ago View the full article
-
By NASA
Cosmic Road Trip: four distinct composite images from NASA’s Chandra X-ray Observatory and the James Webb Space Telescope, presented in a two-by-two grid, Rho Ophiuchi at lower right, the heart of the Orion Nebula at upper right, the galaxy NGC 3627 at lower left and the galaxy cluster MACS J0416.X-ray: NASA/CXC/SAO; Optical/Infrared: (Hubble) NASA/ESA/STScI; IR: (JWST) NASA/ESA/CSA/STScI It’s time to take a cosmic road trip using light as the highway and visit four stunning destinations across space. The vehicles for this space get-away are NASA’s Chandra X-ray Observatory and James Webb Space Telescope.
The first stop on this tour is the closest, Rho Ophiuchi, at a distance of about 390 light-years from Earth. Rho Ophiuchi is a cloud complex filled with gas and stars of different sizes and ages. Being one of the closest star-forming regions, Rho Ophiuchi is a great place for astronomers to study stars. In this image, X-rays from Chandra are purple revealing infant stars that violently flare and produce X-rays. Infrared data from Webb are red, yellow, cyan, light blue and darker blue and provide views of the spectacular regions of gas and dust.
X-ray: NASA/CXC/MIT/C. Canizares; IR: NASA/ESA/CSA/STScI/K. Pontoppidan; Image Processing: NASA/ESA/STScI/Alyssa Pagan, NASA/CXC/SAO/L. Frattare and J. Major The next destination is the Orion Nebula. Still located in the Milky Way galaxy, this region is a little bit farther from our home planet at about 1,500 light-years away. If you look just below the middle of the three stars that make up the “belt” in the constellation of Orion, you may be able to see this nebula through a small telescope. With Chandra and Webb, however, we get to see so much more. Chandra reveals young stars that glow brightly in X-rays, colored in red, green, and blue, while Webb shows the gas and dust in darker red that will help build the next generation of stars here.
X-ray: NASA/CXC/Penn State/E.Fei It’s time to leave our galaxy and visit another. Like the Milky Way, NGC 3627 is a spiral galaxy that we see at a slight angle. NGC 3627 is known as a “barred” spiral galaxy because of the rectangular shape of its central region. From our vantage point, we can also see two distinct spiral arms that appear as arcs. X-rays from Chandra in purple show evidence for a supermassive black hole in its center while Webb finds the dust, gas, and stars throughout the galaxy in red, green, and blue. This image also contains optical data from the Hubble Space Telescope in red, green, and blue.
Spiral galaxy NGC 3627.X-ray: NASA/CXC/SAO; Optical: NASA/ESO/STScI, ESO/WFI; Infrared: NASA/ESA/CSA/STScI/JWST; Image Processing:/NASA/CXC/SAO/J. Major Our final landing place on this trip is the farthest and the biggest. MACS J0416 is a galaxy cluster, which are among the largest objects in the Universe held together by gravity. Galaxy clusters like this can contain hundreds or even thousands of individual galaxies all immersed in massive amounts of superheated gas that Chandra can detect. In this view, Chandra’s X-rays in purple show this reservoir of hot gas while Hubble and Webb pick up the individual galaxies in red, green, and blue.
ACS J0416 galaxy cluster.X-ray: NASA/CXC/SAO/G. Ogrean et al.; Optical/Infrared: (Hubble) NASA/ESA/STScI; IR: (JWST) NASA/ESA/CSA/STScI/Jose M. Diego (IFCA), Jordan C. J. D’Silva (UWA), Anton M. Koekemoer (STScI), Jake Summers (ASU), Rogier Windhorst (ASU), Haojing Yan (University of Missouri) NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.
Read more from NASA’s Chandra X-ray Observatory.
For more Chandra images, multimedia and related materials, visit:
https://www.nasa.gov/mission/chandra-x-ray-observatory/
Visual Description:
This release features four distinct composite images from NASA’s Chandra X-ray Observatory and the James Webb Space Telescope, presented in a two-by-two grid.
At our lower right is Rho Ophiuchi, a cloud complex filled with gas, and dotted with stars. The murky green and gold cloud resembles a ghostly head in profile, swooping down from the upper left, trailing tendrils of hair. Cutting across the bottom edge and lower righthand corner of the image is a long, narrow, brick red cloud which resembles the ember of a stick pulled from a fire. Several large white stars dot the image. Many are surrounded by glowing neon purple rings, and gleam with diffraction spikes.
At our upper right of the grid is a peek into the heart of the Orion Nebula, which blankets the entire image. Here, the young star nursery resembles a dense, stringy, dusty rose cloud, peppered with thousands of glowing golden, white, and blue stars. Layers of cloud around the edges of the image, and a concentration of bright stars at its distant core, help convey the depth of the nebula.
In the lower left of the two-by-two grid is a hazy image of a spiral galaxy known as NGC 3627. Here, the galaxy appears pitched at an oblique angle, tilted from our upper left down to our lower right. Much of its face is angled toward us, making its spiral arms, composed of red and purple dots, easily identifiable. Several bright white dots ringed with neon purple speckle the galaxy. At the galaxy’s core, where the spiral arms converge, a large white and purple glow identified by Chandra provides evidence of a supermassive black hole.
At the upper left of the grid is an image of the distant galaxy cluster known as MACS J0416. Here, the blackness of space is packed with glowing dots and tiny shapes, in whites, purples, oranges, golds, and reds, each a distinct galaxy. Upon close inspection (and with a great deal of zooming in!) the spiraling arms of some of the seemingly tiny galaxies are revealed in this highly detailed image. Gently arched across the middle of the frame is a soft band of purple; a reservoir of superheated gas detected by Chandra.
News Media Contact
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
Lane Figueroa
Marshall Space Flight Center
Huntsville, Ala.
256-544-0034
View the full article
-
By NASA
Xinchuan Huang Let’s start with your childhood, where you were born, where you’re from, your young years, your family at the time, what your parents did, and how early it was in your life that you decided you’d like to pursue a career like the one you’re pursuing now?
I was born in a small town in Sichuan, China. It is not far from the famous Emei Mountain, and the beautiful Qingyi river runs through it. At the beginning, I lived with my grandmother’s family in a small village on the riverbank, called “Pond in heaven”. After I left there at four years old, I lived with my parents in Sichuan and Xinjiang provinces, alternatively, as my parents had been working apart. Luckily their reunion came after three years, and finally there was a real “home” for us. My parents were both high school teachers, they worked in the school system opened by a research institute for the children of their employees. It has elementary schools, middle schools, and high schools. That’s where I grew up and received my pre-college education.
The Emei Mountain lookout. In China, it is the holy site of Samantabhadra Bodhisattva in Buddhism. Many monkeys live there. Family photo when Xinchuan was 2 yrs. old The Qingyi river runs through Xinchuan’s home village. Since I was young, my mother has taught me enlightenment and urged my study. While my father was not quite involved in my academics, he valued the importance of reading and cultivated my interest in books. Every time we walked into a bookstore together, I was just purely happy because it simply meant one or two new books were coming home with me. He encouraged me to keep expanding my knowledge and horizons by also subscribing to many educational magazines and newspapers for kids, among which I remember two of my most favorite magazines. Before elementary school it was the “Children’s Science Pictorial”, and in elementary school it was the “Youth Science”. Those magazines started and nurtured my interest in science and the universe.
In middle school, there was an advertisement for a simple and cheap monocular telescope. I told my dad about it and he helped me order one, even though all it could show was the craters on the moon. But I was so excited, I could lay on the cold ground, watching the moon for hours, as if a new world was unfolding in front of me. Seeing how much I enjoyed it, my father later ordered for me the astronomy volume of the Chinese Encyclopedia. It cost 20 Yuan, which was not a small amount at that time. I was so thrilled to have the book. Holding that hardcover book, I felt that I was holding the universe in my arms.
I can imagine!
But most contents in that encyclopedia were still too advanced for me at the time, so I was more obsessed with the colorful photos in the book. Along with my interest in space and the universe, I was also interested in the topics of UFOs and extraterrestrial civilizations. For example, I read a book called “The Mystery of Flying Saucers”, which was a collection of reports and discussions translated from French. In that book, it mentioned the Drake equation for estimating the likelihood of civilizations in the universe. It deeply impressed me. In 2009, after my postdoc at Ames, I had an opportunity to meet with Dr. Drake. He’s the author of the equation and the founder of the SETI Institute. I must say that not everyone has the opportunity or the luck to meet an idol from their childhood and truly chat with him.
Good luck indeed!
However, when I told Dr. Drake that my first time reading about his equation was in a book of UFOs, he laughed and said “(it) was in a wrong story!” (laughs)
Dr. Drake (left) and Xinchuan at SETI Institute (2010) When I graduated from high school, I did consider a major in astronomy, but there were very few undergraduate astronomy majors in China universities. The only few available that year were either not recruiting in Sichuan or in a city I didn’t like. The famous Peking University did have astrophysics major, but each year they only recruited about 10 undergraduate students from the whole country, and few from Sichuan. Otherwise, I could have enrolled there thirty years ago.
Any idea why they didn’t place more emphasis on astronomy? China, as you know, has a strong reputation in space exploration.
There is tradition for astronomy in China, and people know of ancient records and scientists, but it likely wasn’t the focus at that time. The astronomy and astrophysics research of Peking university and other China institutions have expanded significantly in last 30 years.
That’s for sure.
Anyway, I was admitted to the Fudan University in Shanghai, to major in Applied Chemistry II. That’s an interesting name. Usually you see chemistry, applied chemistry, materials chemistry, etc. What does the “II” mean? Previously, it was the Radiochemistry major, but people adjusted its content to keep up with the growth of economy, and to make it easier for their students to find jobs. There was already a major of “Applied Chemistry” in the Chemistry department, so it became “Applied Chemistry II”. My undergraduate thesis was done in the Institute of Laser Chemistry at Fudan, on the UV dissociation of a small organic molecule under cryogenic matrix isolation conditions.
Well, you certainly were well served by both your parents, as they helped direct your focus and your education. I also looked it up because I had not remembered that you came to Ames as a postdoc when I was associated with the NPP program as the Ames representative.
Yes.
In Tim’s Office. From Left to Right: Ryan Fortenberry, Timothy Lee, Xinchuan Huang, and Partha Bera (03/2011) I don’t remember all of them of course as there were quite a few over that period of time, but I hope that was a good experience for you. You were working with Tim Lee as your advisor and I’d known him for a very long time.
I appreciated and enjoyed the opportunity of doing my postdoc at Ames. I had been thinking of other career choices right before Tim sent an email to Joel (my PhD advisor) asking if there was any student suited for a research project at Ames, about ammonia’s Infrared spectrum calculations. The target was to generate a complete IR line list which people can utilize to characterize the NH3 related celestial environments and eliminate all the NH3 features from the astronomical observations, such as those in Titan’s atmosphere. It was a very good match to my Ph.D. background on the potential energy surface and vibrational dynamics of water cluster ions.
You had another postdoc before you came to Ames? At Emory University?
Yes, that was more like a one-year extension after the thesis defense, to finish up my Ph.D. projects.
How did you get from China to the United States? Was it because of your educational pursuits?
During my undergraduate study, I had some interest in laser chemistry and spectroscopy. For example, photodissociation products were detected and characterized by their infrared spectrum, and we know the spectroscopic fingerprints of molecules are determined by their nature, or internal properties. After college, I became a graduate student at the Institute of Chemistry, Chinese Academy of Science, in Beijing. Supposedly I should learn how to use a femtosecond laser system to investigate some ultra-fast processes in chemical reactions, but my supervisor left the institute unexpectedly.
So, I applied to some graduate programs in United States, and later enrolled in the chemistry department of Emory University in Atlanta. The admission could be related to my background in laser chemistry labs, but I didn’t continue that path. Instead, I changed to theoretical chemistry and vibrational dynamics studies. But I always admired our colleague experimental spectroscopists working in the laboratories, perhaps because I have myself witnessed how difficult an experimental study could become. It may include sample preparation, optical path platform construction, vacuum pumps, laser tuning, circuit of detectors, hardware interface and software development, etc., so requiring a variety of knowledge and skills from chemistry, physics, to mechanics, electronics, and even materials and computer science. Compared to that, it is relatively simpler to do theoretical spectroscopic studies. But from our perspective, our work still belongs to the laboratory astrophysics. Our lab is set up inside computers, and our equipment and devices are computing programs and algorithms.
Did you come to Emory because of a connection or a contact with them? Or did they just have a good program in what you were studying?
I applied to several graduate programs in the US, and received admissions including Emory, but I had no connections with them before. I chose the physical chemistry graduate program at Emory, for their reputation in both experimental and theoretical research.
So, you applied to several programs and you chose and got admitted to Emory. And then what was your route to Ames? Was it your postdoc? You got a postdoc here and then you stayed?
Yes.
That’s very straightforward.
Straight and simple.
Did you know Tim at all beforehand? From a conference or something like that?
Not personally, except that he was an expert in Coupled Cluster theory. After Tim contacted my advisor in the summer of 2005, I met him later that year in the ACS meeting at D.C.
You were going to tell us something about the work that you are doing, which I found very complicated. It had to do with something called a “potential energy surface” and some other things which I don’t even know what they are, but let’s go ahead because one of the reasons we asked this question is because we want to know why it is important enough that taxpayers should fund research into it.
Our research focuses on the Infrared and microwave spectrum ranges, provides high quality spectroscopic constants, or highly accurate Infrared line list predictions for small molecules in outer space. Those molecules play important roles in the interstellar medium, atmospheres of solar system objects, like Venus and Titan, and atmospheres of brown dwarfs and exoplanets. The IR spectroscopic constants and line lists will facilitate the detection of those molecules, help characterize the physical conditions of related environments, determine column densities or atmospheric concentrations, and improve the chemistry evolution models. Since a large part of the astronomical research involves spectrum data analysis and modeling, naturally more reliable and more accurate reference data will be needed to better support NASA strategic goals, help maximize the scientific output of various NASA missions, and eventually help us better understand what’s going on in the universe.
Inside SOFIA flight as a Guest Investigator (09/2015) EXES observation towards Orion KL/IRc2 (09/2015) Sgr B2, looking for c-C3H3+ IR features (09/2015) In the last two decades, the generation of more accurate reference data and predictions has required us to combine the advantages of experiments and theories. Our colleagues in Europe adopted similar strategies. For example, the latest Infrared line list we computed for hot carbon dioxide up to 3000 K has several components: high quality ab initio potential energy surface refined using reliable, high resolution experimental data or models, and the best dipole moment surfaces with accuracy already verified by recent highly accurate experiment IR intensities, and the most accurate line positions from the experiment based effective Hamiltonian models. In this way, the spectral line position and intensity accuracy from existing experiment data are integrated with the completeness, reliability and consistency from theoretical predictions. We hope the line list can improve the accuracy of CO2 analysis and modeling for brown dwarf and hot exoplanet atmospheres, which include, but not limited to the recent CO2 discoveries that JWST made on exoplanets.
Hot CO2 IR Simulation at 1980 K using our AI-3000K line list, compared to experiment, UCL-4000, and HITEMP2010. See details in “AI-3000K Infrared line list for hot CO2” (Huang et al, 2023, JMSpec) open access. On the other hand, like I mentioned earlier, some molecules, like methyl cyanide, SO2, and ammonia, generate a plethora of spectral lines, appearing like wild grasses. That’s why some molecules were called “weeds”. They’re the “weeds” in the field of spectrum and may overshadow other important signals. Once I looked at a small segment of SOFIA EXES spectrum at 20 mm. Although I already knew it contained hundreds of sulfur dioxide bending mode transitions, I did not expect that so many very weak oscillations and tiny bumps in the observed spectrum could be excellently explained and reproduced until I ran the simulations by myself using SO2 line lists. Without a reliable and complete line list, many weak features may go unnoticed and treated as noises. But when you have a good line list, you can identify all the features of a specific molecule, then try to remove them, like removing weeds, so more interesting features or molecules can be found. We may call them the “flowers”. From this angle, we are like farmers in the spectroscopy field, or treasure hunters in the jungle of spectrum.
That’s a good way of putting it. And this leads to a greater understanding of what elements of the NASA mission? How does this fit in with what NASA is trying to accomplish, which could be just exploration, or the search for life, or some of the other great questions that NASA is trying to help answer?
There are several potential impacts from the basic scientific research we have been doing. One is to identify those molecules for their existence in the universe, where they are, and how many they are. Second is to figure out what their environment looks like, e.g., the pressure and temperature. An accurate reference line list can help to extract that information from observed spectrum data. The third impact is about some potential biosignature molecules for habitable exoplanets. Like the one we worked on recently, the nitrous oxide or laughing gas, N2O, it is one of those molecules contributing to the transit spectrum of Earth. Another impact is on chemical evolution models. Because our reliable predictions have very high consistency across isotopologues, higher than experiments, we can help to determine more accurate isotopic ratios and evolution history in outer space. In summary, and in the larger picture, we are contributing to the exploration of the universe and the search for habitable planets by providing basic reference data and tools for all NASA missions related to Infrared astronomy, from past Herschel, SOFIA, to JWST, and future ARIEL and other missions.
You mentioned biosignatures, which caught my attention because we’re hoping to find some evidence that we’re not alone in the universe, that there is other biology going on somewhere out there. Almost all of our research focuses on trying to address that, at some level. And it has a lot of popular support, taxpayer support, because they want the answer to that question perhaps most of all.
The IR spectra based astronomical research involves many models and datasets from different sources, like the spectra modeling on the JWST observations of exoplanet atmospheres. Every piece of work has its own uncertainties, which will add up model by model, database by database. A recent study published in Nature Astronomy revealed that the abundance errors resulting from the opacity inaccuracies can be about one order of magnitude larger than those brought on from JWST-quality observations. This is a bottleneck. From this perspective, our study can help to reduce, or to minimize those uncertainties and errors associated with the opacity data. Compared to experimental measurements under certain conditions, we are trying to provide a complete picture for molecules in the full range of IR and MW spectra. The computed line lists can be used to generate more reliable opacity data at different target temperatures. Having more accurate opacity data with uncertainty reduced or minimized, scientists can determine more accurate properties for exoplanets and other objects in the universe.
Have there been any surprising or breakthrough findings or discoveries or something not expected that has come from your work?
Not expected? Let me think. We should be careful about the claims on the strengths and limitations of our work. On one side we should have enough confidence, but every molecule is unique, we also need to properly estimate the limitation of our line list predictions. With the synergy between experimental data and high-quality theoretical calculations, many improvements actually can be expected. If we know clearly what we can do and what our limits are, they are not real surprises. Some predictions may look surprising, but they need verifications from future experiments. If verified, the agreement is still expected. If rejected, it means something we need to explain or fix, not real breakthrough or findings.
If we really want to talk about “surprises”, I can name two kinds of them. One is that we find surprisingly good agreement or high accuracy verification between predictions and experiments. For example, our room temperature CO2 line list. The IR intensity agreement with the best experiment measurement has reached the level of sub-half percent, for both accuracy and uncertainty, and towards 0.1 %, or permille level, 1‰. It was the best level ever achieved for CO2. That’s kind of a surprise because we were targeting a major upgrade, we knew we were doing better, but we didn’t know the improvements would be so good. That is a good surprise, but there could also be an opposite kind of surprise: a similar molecule or band, similar studies following the same track, so we had assumed it should come out as satisfactory as other molecules or bands, but it did not work out. Then we must figure out what’s going on, what we forgot or missed, or what’s the difference. For example, is that due to some unknown electronic state interference, sensitive resonances, potential defects in potential energy surface, or program bugs, etc.?
That is the science part of it.
Those are really the surprises.
You’re a very impressive and accomplished NASA research scientist, that’s obvious. And you’ve pursued that from youth, really, that line of work. Have you ever given any thought to, if you weren’t doing what you’re doing now, is there another dream job that you might like to have pursued if you had gone another way?
When people talk about a dream job, it usually means something that cannot be realized, except in our dreams. Maybe a contractor scientist without the need to worry about funding?
But still a scientist? OK, that’s good too. But what things would interest you if you couldn’t be a research scientist anymore? This is just to get into your personality and find out more about you.
Oh, if I forget the astronomer or scientist dream from childhood? My dream job has changed several times. Right now, I think it would be interesting to be a local tourist guide.
It would indeed. I like that.
It is also good for me, not only helps to get familiar with my neighborhood, community, the natural environment, but also gives me some good exercise! (laughs)
Right!
What advice might you give to a young aspiring student who would like to have a career like yours?
When I graduated from high school and went to Fudan University to study chemistry, I had never thought that one day I could still have the opportunity to work for NASA and become a scientist at SETI, Search for Extraterrestrial Intelligence Institute. I also met Dr. Drake and talked to him. In a way this was already infinitely close to my childhood dreams. In this life, I could not become a real astronomer, the most I can do is some basic and auxiliary research work in the field of astrochemistry and theoretical spectroscopy. But looking back from my childhood and my college, I can’t help thinking of a phrase that I read from Steve Jobs, the Apple founder. What he said was something like: “many seemingly unrelated and even useless points in your life may someday eventually connect together to form a path to your dreams. Every piece of past experience will have its meaning and function and role in your career. It Is only then that we can realize their meaning and their role”. This statement roughly applies to me, though of course my experience has been much simpler.
I like that quote because we don’t always realize as we’re living and moving forward, the significance of various things that happen. Something that’s just a coincidence can have quite an impact on one’s life or direction.
Yes. The universe is infinite, and all the Earth’s science and technology can be found useful in space explorations, sooner or later. If you are interested in the universe, in space sciences, but at the moment you cannot see how your specialty skills or major can be connected to space, don’t worry and don’t give up. Work hard on what you are doing now, whether it’s learning, research, or work, so that when the opportunity comes, you will be ready.
My second piece of advice was borrowed from Professor Yuan-Tseh Lee, a Nobel Prize winner in Chemistry. About 20 years ago I met him at a conference. At that time, people were talking about innovations everywhere, but I could not find out how to innovate at all, no matter where I looked, so I asked him for advice. Professor Lee said innovation is not like that; innovation comes from years of continuous accumulation and improvements. He said first you need to get very familiar with what you have at hand, get to the bottom, fully understand principles and techniques of what you are doing, and then try to make improvements. There is always room for improvements, and even a tiny improvement will count and will help. Keep improving, a little bit here, a little bit there. Over time, this will eventually lead to real innovation and breakthroughs. My understanding or take away from his replies, is just like the ancient Chinese saying: “No accumulation of steps, no distance to thousands of miles; no accumulation of small streams, there will be no rivers and seas.” That’s it.
Very good answer, thought provoking and true. Thank you for sharing that. Would you like to tell us anything about your family? Are you married? Do you have children?
Yeah, I’m married, and my wife was also from the Chemistry Department of Emory. But she works in the field of organic chemistry, which I could never figure out since my college years. (laughs) And we have two daughters, one in elementary school and the older one in high school. Our daily lives are kind of routine. Like driving the kids to school, back home doing my work, sometimes accompanying kids doing their homework, taking them to extra-curricular activities, cooking, etc.
Rainbow at Ke’e beach (2007) Moreton Bay fig trees and “dinosaur egg” in Allerton Garden (2021) We have a favorite travel destination, the Kauai Island in Hawai’i. Our first visit to Kauai was in 2007, and we really, really like it. I went there more often than my family: I have been there seven times! (laughs) I enjoyed looking out to the west of Pacific Ocean at the end of the Waimea canyon and walking on the Ke’e beach at the east end of the Na Pali Trail. If there is a chance, I may think about living there after retirement.
You could do worse than that! In fact, that might be the answer to the next question, which is: with all your work and family responsibilities, and everything that you are involved in, what do you do for fun?
My interests include reading, like history, literature, and sci-fi books. I like sci-fi fictions and TV shows, such as “The Expanse” series, “The Peripheral” from last year, and the “Three-Body” TV series from China. For fun, I like Chinese Crosstalk, which is a comic dialogue between two people. Every year I also like to pick cherries and nectarines from farms in Brentwood.
Cherries and nectarines we picked from Brentwood farms. Because I use my phone or camera like a recorder, I took too many photos here and there, far more than truly memorable moments. Those photos are a big headache when compiling a family yearbook. After our first child was born, it’s great fun to make annual photobooks for each year.
It’s wonderful that you do that. That will pay dividends in the future, for sure.
Before the pandemic, I also liked to have lunch together with a few colleagues every couple of weeks in some Chinese restaurants nearby, and most of the time we order spicy Chinese food.
You like that? I like that too, although not too spicy! What has been a prime inspiration for you in your life? Something that motivated you to accomplish all that you’ve accomplished so far. Is there a person that you particularly liked? Drake, for example, and his work, that helped to inspire you going forward?
A major motivation has been my curiosity about nature and stars. For inspirational figures, there were many – yes, Dr. Drake was one, because his work inspired people to think more seriously about the relation between life and the universe, and motivated me to make my own contributions. There was also inspiration from Professor Lee. After he won the chemistry Nobel Prize in 1986, there was a lot of laser chemistry related research going on in China. That’s what inspired me too, and why I asked him for advice.
This has been wonderful. I’ve learned a lot about you and that is the whole purpose of this series. Thank you very much. We’ve enjoyed chatting with you.
Thank you. It is great to have this opportunity to chat with you, I enjoyed it too.
View the full article
-
By European Space Agency
An international team of astronomers have used the NASA/ESA/CSA James Webb Space Telescope to discover gravitationally bound star clusters when the Universe was 460 million years old. This is the first discovery of star clusters in an infant galaxy less than 500 million years after the Big Bang.
View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.