Astrobites at AAS 241: Day 1

Welcome to the winter American Astronomical Society (AAS) meeting in Seattle, WA, and online! Astrobites is attending the conference as usual, and we will report highlights from each day here. If you’d like to see more timely updates during the day, we encourage you to search the #AAS241 hashtag on Twitter. We’ll be posting once a day during the meeting, so be sure to visit the site often to catch all the news!

Table of Contents:


Fred Kavli Plenary Lecture: Jane Rigby (NASA Goddard Space Flight Center) (by Graham Doskoch)

AAS 241 kicked off with one of the most anticipated plenary talks of the week. Dr. Jane Rigby, the Project Scientist for Operations for JWST, has helped shepherd the telescope through many of its crucial milestones, from the tests upon tests upon tests before it even left the ground to the agonizing hours of launch day to the long, arduous process of scientific commissioning. She was chosen to give the Fred Kavli Plenary Lecture in recognition of her work to build and operate what might be the most important telescope of this decade and the next.

Dr. Rigby began by reflecting on the early days of gravitational lensing surveys, and the wealth of information that can be obtained from this phenomenon, including spectra and possibly details on individual stars within lensed galaxies. JWST was expected to significantly improve on previous observations – and it hasn’t stopped there. Its scientific performance has exceeded expectations across the board, from its point spread function, to its guiding and pointing accuracy, to its sensitivity to background light and stray photons. Over 20,000 people were involved in the telescope’s design, construction, deployment or operation in some way, their work has paid off.

As a brief interlude, Dr. Rigby talked about the human side of this endeavor. She discussed the tense days during and after JWST’s launch, saying, “It’s a lot like having a newborn at home. . . We didn’t know if the mission was going to be a total failure or if it was going to work.” So many things could have failed, like the unfolding of the solar panels or the deployment of the sunshield.

Fortunately, nothing major failed, and JWST has already produced prodigious amounts of scientific results. Dr. Rigby noted that astronomers have already published 163 papers based on JWST observations – on galaxies alone! In the spectroscopic realm, the telescope has targeted exoplanets, stars and galaxies, probing the cosmos back to a redshift of 13.17 – in other words, when the universe was only a few hundred million years old. The images, too, are phenomenal; she shows a picture of a Wolf-Rayet star in a binary system, which forms concentric circles of dust every eight years.

Before wrapping up her talk, Dr. Rigby took a moment to acknowledge that JWST is “the telescope that 20,000 people built.” That’s what it takes to peer so deep into the cosmos – and the JWST team pulled it off.

Link to live-tweets (by Graham Doskoch): https://twitter.com/astrobites/status/1612475596096917509

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#AbolishQuals: Barriers to Success for Graduate Students of Color in Astronomy (by Pratik Gandhi)

Link to livetweets by Pratik Gandhi: https://twitter.com/astrobites/status/1612509773840412673

One of the first special sessions of this year’s AAS was the panel discussion on qualifying exams organized by the Committee on the Status of Minorities in Astronomy (CSMA). Moderated by Dra. Nicole Cabrera Salazar, co-chair of the CSMA, the panel featured Ph.D. students Erin Flowers (Princeton), Caprice Phillips (Ohio State), and Keshawn Ivory (Vanderbilt), along with professors Enrico Ramirez-Ruiz (UCSC) and David Helfand (Columbia). 

Quals, or qualifying exams, are a staple in most US-based astronomy Ph.D. programs, and often consist of a written and/or oral exam used to try and predict which students are most likely to complete their Ph.D.s and succeed. The panel’s focus was addressing the following questions:

  • What is the purpose of quals in astronomy?
  • What is the effect of quals on marginalized students?
  • Have the existence, structure, and validity of quals been properly examined?
  • What are community sentiments about quals?
  • How do we move forward?

AAS CSMA conducted an informal survey on twitter, with 62 respondents, to gauge people’s thoughts on and experiences with qualifying exams. There was a decent variety of respondents, from professors to students to university staff, and while most of them identified as White, there was representation from a variety of backgrounds/races as well. About half were Cis women, a quarter Cis men, and 16% under the Trans umbrella. 

Image 1: survey results on Ph.D. qualifying exam.

As highlighted in Image 1, the main survey results showed that the majority of respondents did not have positive attitudes towards quals, with 45.0% indicating a negative attitude and 33.3% neutral. Answers to what respondents perceived as the purpose of quals included “gatekeeping”, “illusion of rigor”, “weeding out”, and “negative perpetuation of tradition”. Since there is no standard way of doing qualifying exams and almost every single department does it differently, there is large inconsistency in student experiences, grades, and outcomes across departments and institutions. 

After this initial presentation, the panelists answered questions. The first one was about the structure of the qual at their institution, and these were their responses.

  1. Erin Flowers (Princeton): the qualifying exam was based on the 4 subject courses; panel of 4 faculty members who ask you questions on those courses, with optional additional “fun time” for extra questions.
  2. Caprice Phillips (OSU) ​​took two qualifying exams. At the first one in Texas, Caprice could choose three classes for an oral exam after presenting on research. The second exam at the OSU was more research-focused, with a presentation followed by questions.
  3. Keshawn Ivory (Vanderbilt) will be taking the qual in May! It’s research-based with feedback from a committee on the students’ research proposal, with possible general astrophysics questions related to the research.
  4. Enrico Ramirez-Ruiz (UCSC): three requirements – submit a first-author paper by the end of 2nd year, give a talk to the entire department, and a written exam about core and elective classes. The third requirement was abolished after realizing that it didn’t have the intended learning outcomes.
  5. David Helfand (Columbia): abolished exams a while ago! In their first year, students pick a project, regularly present it to a faculty committee for feedback, and in September of the second year they start a different project and repeat the process. Then they segue into their PhD dissertation.

Next question: how much informed consent is there for the quals in your department? Do students go in knowing what to expect? How transparent is it?

  1. Erin noted that learning about the exam going in happens from older grad students. Once they take their exams, they immediately write down questions to act as a study guide for future students. Faculty did not provide explicit guidelines for the exams during classes!
  2. Caprice said that at OSU there’s a level of transparency, with the professors often indicating potential questions, and you’re allowed to discuss and clarify with faculty.
  3. Keshawn noted that at Vanderbilt, the grad students learnt from more senior grads. This is also common at many other institutions! One hidden component, however, relates to the purpose of the test — to determine whether the student possesses the ability to succeed.
  4. Prof. Ramirez-Ruiz said that UCSC did not have a very transparent exam in the past, but is getting better now. In the past, the written exam did not correlate with metrics for success, and it took a couple of faculty doing that analysis to motivate abolishing it.

Dra. Salazar raised the important point that departments have a responsibility to their students; not just the other way around. Fewer than 1 of 5 PhDs are going to become faculty, so why is there so much of an onus on students to replicate the standardized way of doing academia, instead of training them for a variety of research and other careers? Dra. Salazar also mentioned inertia in psychosocial situations: the idea of abolishing something seems like it’ll never happen because of institutional resistance, so we might never try to actually do it. However, there are institutions that ARE and HAVE BEEN doing it successfully!!!

Audience question: how does your institution treat disabled students going through quals?

  1. Prof. Ramirez-Ruiz said that a lot of the UCSC discussions were triggered because a disabled student had difficulties with the test, which prompted re-evaluation of the exam’s purpose as well as eradicating barriers for students across many dimensions of marginalization/oppression.
  2. Caprice noted that often disability accommodations aren’t genuine, because departments use the extra time students are given to ask them extra questions instead of giving the students more time to think!!! Super important when considering the needs of disabled students.

The conversation started wrapping up with Dra. Salazar highlighted the collective power that graduate students have, pointing to the recent UC-wide strikes as an example. However, the problem is that the onus is usually on the students currently in the program and not on the system!

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Press Conference: Eyes on Galaxies with JWST (by Mark Popinchalk)

Link to live tweets by Mark Popinchalk: https://twitter.com/astrobites/status/1612515024161107970?s=20&t=f2aMqNOoYQkncGpKpmYcXA

The first of eight press conferences for #aas241, which are an opportunity for exciting results to have some additional fan fare. And there is nothing more exciting right now than JWST. The panel of five scientists included Dr. Jeyhan Kartaltepe, Dr. James Rhoads, Dr. Philip Appleton, Dr. Haojing Yan, and Dr. Vivian U, all showing off fascinating new science results using JWST to study galaxies. 

What was striking was the diversity of results, thanks to JWST’s wavelength range being in the infrared. This means the observatory is well suited to look at distant high redshift galaxies, which Dr. Kartaltepe used to describe the shape of 850 galaxies at z > 3, Dr. Rhoads used to link modern “green pea” galaxies to ancient young galaxies, and Dr. Yan used to identify 87 candidate galaxies at z > 11. It can also be used to look at incredible structure in nearby modern galaxies, where Dr. Appleton described new theories for the radiation in a shockwave in Stephan’s Quintet, and Dr. U probed the interior structure of NGC 7469, creating the maps of different gas species around the super massive blackhole. 

Also worth pointing out that running the press conferences this week are Dr. Kerry Hensley, Ben Cassese and Zili Shen – all current or past astrobiters being the voice of the society!

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Plenary Lecture: Jessie Christiansen (Caltech/IPAC-NASA Exoplanet Science Institute) (by Macy Huston)

For the second plenary lecture of the week, Dr. Jessie Christiansen presented “Towards an Exoplanet Demographics Ladder: The Emerging Picture of Planet Populations!” Astrobites interviewed her in this article, and Macy Huston wrote our twitter thread of this plenary talk.

Dr. Christiansen is the Project Scientist for the NASA Exoplanet Archive. She started with an intro to IPAC, the Science & Data Center for Astrophysics & Planetary Sciences at Caltech. IPAC hosts the NASA Exoplanet Archive, which reached the amazing milestone of 5,000 confirmed exoplanets last year!

The next portion of the lecture covered the populations of known exoplanets discovered with each of the four main methods (from most to fewest found): transits, radial velocity, microlensing, and direct imaging. The transit method is great for finding planets on close-in (<1 AU) orbits, and we see an interesting split into two populations, with a gap near ~30 Earth masses. The radial velocity method primarily finds planets that are relatively high-mass and on short to intermediate orbits. Microlensing can detect planets across the planetary mass range and within a ~1-10 AU orbital range. Direct imaging is only possible for very high-mass and wide-orbit planets. So, how do we bring these all together to get a full picture of exoplanet demographics?

A plot of planet mass vs. orbit semi-major axis. The scatted points are grouped by detection method: the transit planets are clustered around the lower left corner, and the next categories move to the upper right: radial velocity, microlensing, and imaging.

Dr. Christiansen discussed the prevalence of Earth-like planets, quantified as η. Based on the Kepler planet sample, initial estimates of η varied by orders of magnitude. With more recent analysis, η is thought to be in the 10-50% range, but the current estimates are consistent with anything from 1-100%. Ongoing refinements of Kepler occurrence rates may help narrow this estimate. Additionally, new exoplanet discoveries from the upcoming Roman Space Telescope and the proposed EarthFinder and Earth 2.0 missions can provide new data sets for this type of analysis.

There are many different types of stars and planetary systems in the Galaxy, so the conditions for planet formation and evolution could impact planetary demographics. Some evidence suggests that Earth-like planets might be more likely to exist in systems that have inner rocky planets and/or outer Jupiter-like planets. Already-discovered systems with planets like these may make good targets for future habitable planet searches. M-dwarfs, the most common type of star, may also be potentially habitable host stars.

K2 and TESS are currently enabling the study of small, short-period exoplanets. Dr. Christiansen’s group recently cataloged ~750 K2 planet candidates ready for demographic study, and validated 60. Kepler and K2 populations both show a bimodality in the size distribution of small planets at short periods. Recent m-dwarf studies suggest the existence of a density bimodality dividing rocky planets and water-dominated planets.

A number of other factors could impact the occurrence rates of planets around certain stellar types and regions. Kepler and K2 suggest that small, short-period planets are more common among stars that stay closer to the Galactic plane (i.e. in the thin disk, not the thick disk). Stellar properties like metallicity and age may also affect formation, as protoplanetary disks require planet-building material and dissipate over time.

To wrap up the lecture, we return to the plot of known exoplanets discovered via the four main methods, plotted by orbital semi-major axis and mass (or mass*sin[i]). But, these masses are indirect estimates for all methods. Additionally, different methods focus on different types of host stars. So, combining the data sets is complicated, but not hopeless! There is overlap between the parameter spaces covered. Dr Christiansen proposes the “planet demographics ladder,” as an analogy to the cosmological distance ladder, to bring the methods together where they overlap. Roman‘s survey of the Galactic bulge will greatly extend our coverage of planets on orbits around and beyond an AU, which will work together with Kepler data to establish occurrence rates including η.

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Press Conference: Mergers, Bursts & Jets (by Ryan Golant)

The second press conference of AAS241 featured four speakers: Dr. Michael Koss of Eureka Scientific, Inc., Professor Vikram Ravi of the California Institute of Technology, Professor Cecilia Chirenti of the University of Maryland, and Sirina Prasad of the Harvard/Smithsonian Center for Astrophysics. The four talks covered a range of exotic high-energy phenomena, from merging black holes and neutron stars to fast radio bursts to radio emission around massive stars.

Dr. Koss spoke about the detection of two extremely close active galactic nuclei (AGN) in the galaxy UGC 4211; with a separation of only 750 light-years, these two AGN form the closest dual AGN system yet detected. This discovery was made possible by the combination of data across multiple regions of the electromagnetic spectrum: the bright nuclei were first identified in the near-infrared (using Keck’s impressive adaptive optics), then followed-up by millimeter observations from ALMA and optical observations from MUSE. UGC 4211 is thought to be the intermediate result of two merging galaxies and could thus serve as a valuable prototype for similar mergers of distant active galaxies; currently, the behavior of close-in merging supermassive black holes is poorly understood, but UGC 4211 should provide useful constraints on this process.

Left panel: a glowing spiral galaxy. The central part is zoomed into the right panel: two disks with a black hole in the center.
Image 1: Illustration of dual Active Galactic Nuclei

Professor Ravi presented the first results from the Deep Synoptic Array (DSA), a new radio telescope at Caltech designed to simultaneously discover and precisely localize fast radio bursts (FRBs). In 2022, DSA discovered 30 FRBs, more than doubling the yield from all other FRB observatories. Furthermore, DSA’s impressive field of view, time resolution, and angular resolution allow it to localize FRBs to one-millionth of square degree on the sky – a localization accuracy roughly 600 times better than that of CHIME, another leading FRB instrument. With its remarkable specs, DSA is seeking both to better understand the origins of FRBs and to use FRBs to study the unseen hot luminous matter around and between galaxies; over 80% of the luminous matter in the nearby Universe is unseen, but the dispersion of radio pulses from FRBs can reveal the spatial distribution of this matter. The first results from DSA have already placed new constraints on the mass of the Milky Way’s circumgalactic medium – these results only used data from one DSA-detected FRB, leaving 29 more FRBs to analyze.

A photo of many radio telescope dishes arranged in a straight line.
Image 2: A photo of the Large Synoptic Array.

Professor Chirenti described the discovery of two hypermassive neutron stars in archival gamma-ray burst (GRB) data. As two neutron stars merge, the system first emits a gravitational wave signal and then launches a short, violent GRB. Detailed computer simulations incorporating general relativity suggest that, in the time between the gravitational wave emission and the GRB, a single extreme neutron star can form; this hypermassive neutron star (HMNS) is short-lived, however, collapsing into a black hole in less than a second. Prof. Chirenti and her collaborators looked through data on 700 short GRBs from the BATSE instrument and identified two bursts (GRB 931101B and GRB 910711) that exhibited the quasi-periodic gamma-ray signal indicative of HMNS formation. These HMNSs demonstrate record-breaking characteristics for neutron stars, rotating twice as fast as the fastest pulsars and possessing 20% more mass than the most massive neutron stars. While we can currently only see these HMNSs via gamma rays, the next generation of gravitational wave observatories will be able to detect them via their high-frequency gravitational wave emission. (Side note: huge props to Prof. Chirenti who, in the face of computer audio issues during her talk, sang the gravitational wave and GRB frequency signals of a binary neutron star merger herself)

Image 3: Artist impression of neutron star merger.

Finally, Sirina Prasad discussed how recent ALMA observations have shed new light on the peculiar binary star system MWC 349. MWC 349a is a massive evolved star surrounded by regions of hydrogen recombination line maser emission; recombination line maser emission – which presents strongly at radio wavelengths – occurs when the capture of free electrons by free protons triggers stimulated emission. Previously, the Submillimeter Array (SMA) had observed maser emission in MWC 349’s circumbinary disk and in an hourglass-shaped region around MWC 349a caused by an ionized wind; while these SMA observations provided useful information on the dynamics of the disk and of the rotating and expanding wind, the precision of the study was limited by SMA’s angular resolution. ALMA’s superior angular resolution provided a much clearer picture of MWC 349’s maser emission regions, both confirming the disk dynamics and revealing a previously unobserved jet emerging from MWC 349a; this is the first time a collimated jet has been detected around a massive evolved star, thus raising new questions about the process of jet formation and the degree to which jets can impact binary star systems.

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Plenary Lecture: Rich Matsuda (California Association for Research in Astronomy) (by Briley Lewis)

The three panelists of the Mauna Kea plenary panel
The panelists from the plenary on Mauna Kea stewardship. From left to right: Rich Matsuda, Dr. Noe Noe Wong-Wilson, John Komeiji. Screenshot of AAS 241 livestream.

Twitter thread: https://twitter.com/astrobites/status/1612601818743459841 (by Briley Lewis)

(Note: if you are unfamiliar with the context of observatories on Mauna Kea, we highly recommend reading/skimming these bites on the history of astronomy on Mauna Kea, the 2019 TMT-related protests, and recent developments with the MKSOA before diving into this session!)

In the wake of the 2019 demonstrations on Mauna Kea and other movements towards social justice, the Astro2020 Decadal Survey recommended that astronomy should engage in sustained conversation and collaboration with local indigenous communities. One outcome of this recommendation is the creation of the Mauna Kea Stewardship and Oversight Authority (MKSOA), a governing body to collaboratively manage the care of the mountain and the future of astronomy on Mauna Kea. This afternoon’s plenary was a discussion, moderated by Ka’iu Kimura, with multiple members of the MKSOA: Rich Matsuda, former director of Maunakea Observatories, Dr. Noe Noe Wong-Wilson, a Hawaiian elder (kūpuna) who participated in the blocking of the summit access road, and John Komeiji, chair of the MKSOA.

“To do the best Earth-based astronomy requires access to places unpopulated by city lights…in many cases, those places also happen to be the ancestral lands of people who connect their lineage and heritage back to the beginning of their Universe there as well,” said Kimura. “That is certainly the case for Mauna Kea.” 

The road to the recent climactic conflict surrounding the Thirty Meter Telescope was long, as Wong-Wilson described in the session. At the time of the first telescopes in Hawai’i, local communities were overwhelmed by other changes brought about by colonization, but as early as the 1980s Native Hawaiians began to speak up in dissent. Despite “following the rules” and attending community meetings, filing public comments, and opening court cases, their voices went unheard, leading to the more severe actions of physical roadblocks in 2019.

Eventually, a working group was formed to determine a path forward and bring together the various voices in the debate around Mauna Kea. Although it was received initially with great skepticism, the working group produced useful recommendations that then became law, creating the MKSOA. Matsuda credits four ingredients to the success of the working group: relationship-building between the group members, creating a safe and equitable space for all to share opinions, gaining a deeper understanding of Hawaiian culture, and centering the one thing they all had in common—the Mauna itself.

The MKSOA is still in its early formative stages, and (as any government entity does) it will take time to fully develop. Around 14 billion dollars have been allocated to the MKSOA, and they will take the next five years to hire staff and get up and running. After that, it is their responsibility to create plans for the future of astronomy on Mauna Kea, for environmental conservation efforts on the mountain, and more. “Our overall purpose is to manage the mountain and try to understand how mutual stewardship actually happens,” said Komeiji.

All three panelists agreed on the deep importance of the task of caring for Mauna Kea, which is not only important for astronomy but also for defining the culture of Hawai’i in future years. “We are going to be the generation that could finally come together and figure out how to take care of our Mauna,” said Wong-Wilson.

“I hope all of you didn’t see this as only a Hawai’i issue, or only an astronomy issue,” added Matsuda. He emphasized that it is a time to think about systems and whether they’re inclusive, equitable, and allowing everyone’s voices to be heard. The working group and subsequent creation of the MKSOA is truly a testament to the power of community-building when the right relations are prioritized, such as the spirit of the Hawaiian Kapu Aloha. Although Matsuda and Wong-Wilson were once seen as polarized opposition in a false dichotomy between science and culture, they have “been able to forge an unbelievable relationship” according to Kimura, praising how the two have come together to create a better future for Hawai’i.

“Out of extreme challenges come opportunities for new ways forward and new relationships,” said Kimura. In the spirit of the MKSOA, she ended the session by encouraging everyone to build relationships with those who have differing opinions – and with the land they are on.

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Newton Lacey Pierce Prize Lecture: Erin Kara (MIT) (by Graham Doskoch)

How do you study the environment around supermassive black holes (SMBHs for short)? These gargantuan beasties may be massive, but when viewed from millions of light-years away, they look small and dim. Fortunately, there’s a way around this – and that was the focus of the plenary talk given by Prof. Erin Kara, the recipient of the Newton Lacey Pierce Prize.

Prof. Kara took us through two intertwined journeys: one personal, one scientific, with valuable lessons from both. Her path through astronomy began as an undergraduate at Barnard College, where she took a physics class taught by Prof. Reshmi Mukherjee and fell in love with the cosmos. She also learned a valuable lesson: always find a good mentor. Prof. Mukherjee certainly was, and Kara soon found herself entering graduate school.

Around the same time, astronomers were making big strides in the study of a subset of supermassive black holes called active galactic nuclei, or AGN. These are SMBHs which are accreting matter; as that matter falls into the black hole, its gravitational potential energy is used to power relativistic jets or is transformed into high-energy x-rays. AGN are more luminous than quiescent SMBHs and can be detected at a variety of wavelengths, but traditional methods couldn’t reach the minute scales needed to probe their inner depths.

Fortunately, astronomers developed a way around this problem with a technique called reverberation mapping. Some of the x-rays created by infalling matter will be “echoed” off the accretion disk, which gives us information about the disk’s structure. Prof. Kara used a more down-to-Earth analogy: audience members could hear sound waves traveling directly from her mouth to their ears, but they could also hear echoes from her as other sound waves bounced off the walls. If someone precisely measured the arrival times of these echoes and calculated the speed of sound, they could determine the shape and size of the room they were in.

Reverberation mapping isn’t quite that simple – but then again, research rarely is. This was the second lesson Prof. Kara shared, the one she learned as a graduate student: every research project ebbs and flows, with periods of stagnation and periods of productivity. The secret to success is having people around you who will support you when you hit those walls.

Taking advantage of the information gathered by reverberation mapping requires adjustments and corrections. For example, AGN exhibit random, stochastic variability, which can drown out the light echoes. Astronomers can get around this by Fourier transforming the data and searching for signals that travel on different timescales than the stochastic variations; these are signals of the echoes. They also have to take into account relativistic effects, from both the intense gravitational pull of the black hole and the fast-moving matter in the accretion disk.

AGN aren’t the only objects that can be studied using reverberation mapping. Other promising targets include tidal disruption events and even stellar-mass black holes in binary systems. The latter group of objects can emit x-rays if their companion is a normal star; astronomers refer to these systems as x-ray binaries. They’re interesting because they undergo outbursts, but on timescales of only months to a year. This makes them potential analogs for AGN, which can evolve similarly but on much longer timescales.

As another interlude, Prof. Kara discussed a third lesson, from her time as a postdoc: branch out in your research, and work with new collaborators. Reverberation mapping is being applied to new types of objects and is yielding exciting new results; the same can be true for any astronomer poking their nose into a new subfield.

The study of x-ray binaries has been aided by NICER, on the International Space Station. Prof. Kara described some work that has been enabled by NICER, led by Kingyi Wang, a PhD student at MIT. Wang created a pipeline to study x-ray binaries and track them over the course of an outburst. Her results show that as the emission changes throughout an outburst, the lag times of light echoes can increase by an entire order of magnitude – so something in the x-ray binary is physically changing size by quite a lot! One possible culprit could be the relativistic jets given off by the accreting black hole.

Prof. Kara gave one final bit of advice, this time from her years as a professor: “Don’t forget about your hobbies!” Astronomers are human beings, not machines; we need rest and relaxation and time away from our work.

Prof. Kara closed the talk by showing some examples of sonification applied to AGN. Sonification is a method of turning images into sounds, making them accessible to visually impaired folks without losing any of the information. She showed several model AGN echoes and their sonified counterparts, joking, “You can hear the general relativity in these simulations!” She was right – and it was spectacular.

Prof. Kara spoke to Astrobites about her experience and you can read the post here.

Link to live-tweets (by Graham Doskoch): https://twitter.com/astrobites/status/1612609355400060928

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JWST Town Hall (by Graham Doskoch)

Judging by the hundreds of papers about data from its first months of observations, astronomers can’t get enough of JWST. Appropriately enough, then, we both began and ended the day with sessions about the telescope and its results. To complement the morning’s plenary lecture by Dr. Jane Rigby, the evening brought us the JWST Town Hall, a set of short talks describing the mission, the telescope’s performance so far, and the resources available to astronomers using it.

Bridget Samuelson, of Northrop Grumman, opened the session with a brief welcome and a reminder of the public recognition JWST has already achieved. Northrop Grumman is one of the leading contractors on the telescope’s design and fabrication, and Samuelson has played several roles during the odyssey to send it to space. She noted that excitement about JWST hasn’t worn off – in fact, the team was just awarded the Goddard Memorial Trophy.

Next to take the podium was Dr. Nancy A. Levenson, who is currently serving as the Interim Director of the Space Telescope Science Institute (STScI). She showed some of the most famous early images from JWST: iridescent nebulae, mind boggling spectra, and deep galaxy fields. Dr. Levenson gave a brief overview of the role STScI plays for JWST. It’s the Missions Operations Center for the telescope, and handles proposals, data collection, communication with observers, and much more. She also drew attention to the JWST Users Committee (JSTUC), which provides a voice for the astronomers using the telescope.

Dr. Levenson was followed by Dr. Jonathan Gardner, of Goddard Space Flight Center, who gave updates on improvements since the telescope’s launch. After a notable micrometeoroid impact in May 2022, the team decided to implement a micrometeoroid avoidance zone in the next observing cycle. In August, an increase in friction was noticed in one of the grating wheels of the Mid-Infrared Instrument (MIRI), leading the team to pause one particular MIRI observing mode until November while the cause was investigated. Dr. Gardner also noted that the telescope briefly went into safe mode in December after a software problem hit the attitude control system, but was brought back online within a couple days, with minimal disruption to science operations.

Dr. Gardner finished by walking through some of the science highlights since observing began last year, including the highest-redshift images taken to date, wonderful exoplanet spectra, and observations of barred spiral galaxies only a few billion years after the Big Bang. Judging by JWST’s images showing up everywhere from Times Square to a Coldplay concert, the public might be almost as excited by the results as the astronomers who found them.

The next speaker was Dr. Jane Rigby, the Project Scientist for Operations for JWST, who had given the Fred Kavli Plenary Lecture that morning on the telescope’s science performance. In her Town Hall segment, she shared similar information, noting that JWST has exceeded expectations in many of its performance metrics. She highlighted how the smooth mirrors have enabled exceptional sensitivity, and the telescope’s pointing and guiding abilities have far exceeded what was required. The micrometeoroid impact was worrisome, but as Dr. Gardner mentioned, measures are being taken to avoid repeat events. Dr. Rigby noted that with two decades worth of fuel, nobody knows what will eventually limit JWST’s operating lifetime – but it will be sticking around for a while.

Dr. Rigby was followed by Dr. Klaus Pontoppidan, who described the work of the Science and Operations Center during Cycle 1 observations. The Center performs a variety of tasks, including coordinating observations, supporting proposal calls for Cycle 2, public outreach, and more. It also continues to improve the automatic calibration pipeline that processes the data, as well as the many tools available to astronomers using JWST or working on proposals.

To give a view of the mission timeline, the next speaker was Dr. Christine Chen, representing the JWST Science Policy Group at STScI. She reminded everyone that the call for Cycle 2 proposals is out, with the submission deadline of January 27 approaching. Over 5000 hours will be available for General Observer Programs, with additional time set aside for parallel, survey or archive programs and JWST Joint Programs with other telescopes, like ALMA or the Hubble Space Telescope. PIs will be notified of decisions in May, and Cycle 2 itself will start in July. Looking further ahead, the call for Cycle 3 proposals will be officially made on August 15, with a deadline of October 27, and Cycle 3 will begin in July of 2024.

As if to inspire the audience to finish any proposals by January 27, Dr. Chen was followed by Dr. Amaya Moro-Martín, who described some of the science highlights from the Early Release Science (ERS) programs. These teams were responsible for some of the first JWST results this past summer, and include the CEERS, TEMPLATE and Q3D groups. Over 175 papers have appeared on arXiv in the 6 months since science observations began, and ERS programs deserve a lot of credit for these early strides.

The session finished with a brief overview of how JWST press releases work. Teams using JWST data who believe they have a significant result can submit their results to STScI, which will make a determination. If the research seems to warrant a press release, STScI will create text and visuals, which will then be reviewed by the team and by NASA. The overarching lesson is to talk to the STScI team sooner rather than later, to give them adequate time to work on a release before a paper is published.

Link to live-tweets (by Graham Doskoch): https://twitter.com/astrobites/status/1612636189953085442

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