Board of Visitors Summer Meeting Showcases Breakthroughs in Cosmic Discovery

Friday, July 25, through Saturday, July 26, McDonald Observatory hosted the annual Board of Visitors Summer Meeting. Featuring science talks, discussion groups, and telescope tours and viewings, the event connected almost 200 attendees with the latest astronomical research. Although there were minor bouts of stormy weather, each evening the clouds cleared to reveal clear views of the night sky.

This year’s program provided an advanced glimpse of the Hobby-Eberly Telescope Dark Energy Experiment’s (HETDEX) highly anticipated results and explained the core scientific concepts behind its success.

Talks on HETDEX shared:

• Preliminary results and how the project was able to achieve them
• How observing galaxy clustering in the universe can be used to measure its expansion
• Unexpected findings in the HETDEX data and what they may mean

In addition, science discussion groups shared the unexpected challenges of maintaining telescopes; the importance of artificial intelligence in cosmological analysis; new research on molecular clouds; and how exhibits connect the public with our science.

Science Talks

The HETDEX Survey, Science, and Results

Karl Gebhardt, Astronomy Department Chair

Gebhardt unveiled the first scientific results from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). In the twenty years since its conception, the project has created the largest map of galaxies in the early and nearby universe. By calculating the distances between various galaxies, HETDEX has identified patterns in the distribution of matter and, in turn, how quickly the universe was expanding 11 billion years ago. This will help astronomers finally uncover the nature of dark energy – the mysterious substance causing the universe to expand more and more quickly.

Galaxy Clustering: A Large-Scale Ruler for Cosmology

Kuan Wang, HETDEX Cosmology Fellow

HETDEX uses patterns in galaxy clustering to measure the expansion of the universe during different epochs. Sounds waves from the Big Bang rippled through the early universe, causing subtle over- and under-densities in matter. As the universe cooled, these ripples – called Baryon Acoustic Oscillations (BAO) – became frozen in place. As the universe expanded, so did the ripples.

Though they aren’t visible, BAO can be detected by measuring the distance between galaxies. This technique has been key to the success of HETDEX in identifying the expansion rate of the early universe.

Serendipity in Science: Finding Lyman Alpha Absorption in HETDEX

Laurel Weiss, Astronomy Graduate Student

When an electron in hydrogen drops from an excited state to ground, it releases a burst of energy known as a Lyman alpha emission. This emission line, seen as a dramatic peak in spectral data, acts as a tell-tale sign of the presence of a galaxy. Identifying Lyman alpha emissions has allowed HETDEX to map the far-off universe.

As part of her Ph.D. research, Weiss noticed an unexpected and consistent dip in the lines on either side of the Lyman alpha data. These troughs aren’t typical, so she launched an investigation. Through her research, she concluded that the light from these galaxies was being removed twice – once when background light was subtracted from the data and then again when light from these galaxies traveled through clouds of gas and dust on its journey to Earth. 

Science Discussion Groups

A Bright Future for an Old Telescope: Refurbishing the HJST

Niv Drory, Senior Research Scientist

Originally built in the 1960s, the Harlan J. Smith Telescope remains a vital tool for modern astronomy. That’s possible through ongoing upgrades to its instrumentation. However, implementing these upgrades isn’t always a straightforward task. Drory shared an overview of the unique challenges that come with maintaining the telescope - missing, incomplete, or inaccurate documentation; unmarked wiring; classified electrical component data sheets; lost knowledge – and how the McDonald team overcomes these hurdles.

HETDEX in the Age of Artificial Intelligence: Decoding the Nature of the Cosmos

Mahdi Qezlou, HETDEX Cosmology Fellow

Machine learning is revolutionizing the analysis of astronomical data. To understand the evolution of the universe, HETDEX runs simulations on how variations in ten factors in the early cosmos – the amount of matter present, its distribution, and more – would play out over time. Because astronomers have to take so many factors and so much data into account, machine learning is vital to this process. A simulation that would take 343,000 years to run manually now only takes three months.

Do All Interstellar Clouds Form Stars? If Not, Why Not?

B-G Andersson, McDonald Observatory Assistant Director for Research Support

Andersson’s research probes a common assumption in astronomy: that all interstellar clouds eventually form stars. The recent discovery of a nearby molecular cloud, named Eos, presented astronomers with a unique opportunity to study star-formation up close. However, follow-up observations using the Tull Spectrograph on the Harlan J. Smith Telescope have shown no signs of it. This may be due to the hot stars already present nearby pushing out a hot bubble of gas and destroying the conditions required for new star formation. Follow-up studies will provide more insight into the cloud’s chemistry and if it is in the process of evaporating.

New Horizons: McDonald Observatory Exhibit Development and Collaborations

Katie Kizziar, McDonald Observatory Assistant Director for Education and Outreach

Kizziar shared how the Observatory researches and develops engaging and educational astronomy exhibits for the public. As a top tourist destination in the area, these exhibits are an important way the Observatory fulfills its mission to advance humanity’s knowledge of the universe. New updates will ensure we communicate the latest science.

Towards this goal, McDonald Observatory also partners with institutions across the state. Recently, this has included collaborating on the “Big Eye on Dark Skies” exhibit at UT Austin’s Texas Science & Natural History Museum and an upcoming astronomy exhibit with the Grace Museum in Abilene.