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Jacqueline Antwi-Danso …NSERC Banting Postdoctoral Fellow at the David A. Dunlap Department for Astronomy & Astrophysics

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• Jacqueline Antwi-Danso
• Jacqueline Antwi-Danso

 In the 1990s, astronomers discovered two distant, mas­sive galaxies that had com­pletely stopped, or quenched their star formation. The discovery marked a complete shift in everything astrono­mers thought they knew about how galaxies formed.

Massive galaxies like the Milky Way took several billion years to form. But those new­ly discovered galaxies did so in just a fraction of that time.

“The discovery meant that these galaxies were older than the age of the universe, which is physically impossible,” says Jacqueline Antwi-Danso, the NSERC Banting Postdoc­toral Fellow at the David A. Dunlap Department for Astron­omy & Astrophysics.

Ms Antwi-Danso
Ms Antwi-Danso

“When we look at the formation histories of these distant quenched galaxies, the observations suggest that they formed too quickly and too early compared to what we see in cosmological simula­tions.”

Antwi-Danso is tackling one of astronomy’s biggest chal­lenges in her search to find the earliest distant quenched galaxies in the universe. She is particularly interested in how these galaxies formed and when they stopped forming stars.

Astronomers have discov­ered several more distant, quenched galaxies at increas­ingly earlier periods in the universe’s history. These gal­axies are more massive than the Milky Way and yet formed within a billion years of the Big Bang (which happened nearly 14 billion years ago). In other words, they formed their stars extremely rapidly, unlike any galaxy observed in the present-day.

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So, what does this all mean for astronomers? The extreme star formation processes implied by these observations of distant quenched galaxies are uncomfortably close to the limits permitted by galaxy formation physics. Therefore, trying to understand these objects in more detail is a high priority research area for astronomers.

Massive galaxies like the Milky Way have up to a trillion stars and are characterised by luminous, spiral-like arms of active star formation. Meanwhile, distant, quenched galaxies are composed of old stars and look like relics: small orange-red blobs. This is because their light has been “stretched out” to infrared wavelengths due to the ex­pansion of the universe, which also makes them fainter and harder to spot.

At U of T, Antwi-Danso is building on significant findings from a study she participated in as a PhD student at Texas A&M University. Using the 8-metre telescope at the Gemini South Observatory based in Chile, the FENIKS collaboration surveyed large areas of the sky to increase the chances of finding these rare massive galaxies. They designed and installed two new imaging filters on the telescope to push the bound­ary of what was possible with ground-based infrared tele­scopes. The survey led to two critical discoveries.

The first was the identi­fication of two new distant quenched galaxies. The discovery confirmed existing knowledge about the for­mation histories of distant galaxies, “namely, that these galaxies form too early and too quickly based on what theory predicts,” Antwi-Danso explains.

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The study also highlighted that astronomers can reliably use ground-based telescopes to observe distant quenched galaxies as far back as 12.5 billion years into history of the universe. To detect them at earlier times than this, space-based data is required.

Additionally, astronomers are rethinking long-standing models of galaxy formation as they observe distant quenched galaxies with supermassive black holes at their centers emitting energetic radiation.

This is important, Ant­wi-Danso says, because the differing models for light emission from stars and super­massive black holes can affect estimates of the physical properties of these distant galaxies.

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As more questions arise, there is an increasing need to ensure the accuracy of the physical properties of distant quenched galaxies derived from modeling their observa­tions. Fortunately, there have been significant technological advancements to address this need.

Harnessing the power of space-based technology

• Ms Antwi-Danso was reconized as a
Pillar of University Leadership in 2017
• Ms Antwi-Danso was reconized as a Pillar of University Leadership in 2017

The next stages of Ant­wi-Danso’s research involve further exploration of those two distant galaxies she dis­covered from Chile. To do so, she’s leveraging the power of the James Webb Space Tele­scope (JWST).

Distant galaxies are hard to detect because their emit­ted light is shifted to infra­red wavelengths, where the earth’s atmosphere blocks most of the light. The sky in the infrared is about 10,000 times brighter than the typical distant massive galaxy. This makes it extremely difficult to detect the most distant quenched galaxies using ground-based telescopes.

The JWST – which launched in December 2021 – is about 100 times more sensitive than the largest ground-based infrared telescopes and can observe galaxies in a fraction of the time of its predeces­sors.

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In fact, it has doubled the number of spectroscopic ob­servations of the most distant, quenched galaxies within only two years of operation. Before its launch, astronomers had spectra of only 35 of these galaxies observed within the first two billion years of the universe’s history.

To further observe those two galaxies, Antwi-Danso will use data from the JWST to ex­amine their spectra – the light emitted by these galaxies over a range of wavelengths – which can reveal information like chemical composition. Insights will help provide a more accurate understanding of their formation histories to compare with updated cosmology simulations, and, hopefully, offer new an­swers about possible tensions between theory and observa­tions.

Additionally, Antwi-Danso is part of the Canadian NIRISS Unbiased Cluster Survey (CA­NUCS), a multi-institutional collaboration that uses gravi­tational lensing — a phenom­enon where a massive object acts as a cosmic magnifying glass — to study the building blocks of the earliest galaxies.

Within that collaboration, Antwi-Danso is also a re­searcher on the Technicolor Survey, which employs mul­tiple filters on the JWST’s Near-Infrared Camera to observe quenched galaxies at wavelengths that are inacces­sible from the ground.

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“We want to find galaxies that contain the first gen­erations of stars, and then model their observations with galaxy formation models to infer their physical properties and star formation histories,” Antwi-Danso says.

With the technological advantages provided by the JWST to push the boundaries of distant galaxy observations, Antwi-Danso’s research will provide valuable insight into understanding how early gal­axies came to be.

“We’re really excited to see where the results lead and to compare those observa­tions with current theoretical predictions for these distant massive galaxies.”

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Trailblazer: The woman who found purpose in her roots

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Mrs Osei Bonsu
Mrs Osei Bonsu

“We are always told what it is that we can’t do, but we must not allow the limitations placed on us to define who we are as women”- Mrs Lynn Osei-Bonsu

For many children raised in diplomatic homes, the world becomes a familiar territory where they easily get accustomed to. Countries change, schools change, friends change and home itself becomes fluid like a traversing stream.

However, for Mrs Lynn Osei Bonsu, one of Ghana’s foremost female communications strategist and philanthropist, life’s most defining lesson would come not from the polished streets of New York, where she spent part of her childhood, but from the quiet town of Jirapa in the Upper West Region.

Mrs Bonsu

Today, she leads uNuru Communications Group, a strategic communications firm delivering not just for its clients, but also helping in shaping the brand Ghana.

She also heads Trailblazers, a non-profit organisation committed to supporting women and children.

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Yet behind the polished corporate image is a deeply human story of identity, sacrifice, resilience and purpose.

A childhood between worlds

Born to Mr Hilary K. Ziniel, a diplomat father and Mrs Rose Ziniel a teacher mother, from Goziir in the Nandom District of the Upper West Region, she spent much of her early life outside Ghana due to her father’s regular postings with the Ministry of Foreign Affairs.

“My first memories are not growing up in Ghana,” she told The Spectator with utmost fondness.

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Mrs Bonsu at an event

But while her childhood stretched across countries and cultures, her father remained determined that his children would never lose sight of where they came from, as result when the family returned to Ghana after his postings in New York, he made a decision about Lynn’s education that initially devastated her.

Instead of enrolling her in one of the prestigious schools in Accra, he sent her to St. Francis Girls’ Senior High School in Jirapa. “He said I needed to know where I came from,” she recalls.

Harsh transition

Moving from New York to Ghana and immediately being dispatched to Jirapa for her secondary education came with what she describes as a “huge culture shock.”

There was limited electricity, no running water and a pace of life completely different from anything she had known. “At the time, I thought he was punishing me,” she says with a laugh.

Years later, however, that painful transition would become one of the greatest gifts of her life. “If my father were alive today, I would thank him every single day for that decision,” she says quietly.

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The experience, she explains, grounded her. It taught her humility, resilience and gratitude. More importantly, it gave her a deeper appreciation of sacrifice.

“It gave me a different outlook on life and a greater appreciation for my parents and everything they did for us.”

After secondary school and sixth form education, she gained admission to Carleton University in Canada. At the time, studying abroad was considered a major achievement for many Ghanaian families, especially for children from internationally exposed homes. But once again, her father encouraged her to think beyond prestige.

“He told me that if I wanted to live and work in Ghana, then I needed to build my network here,” she says.

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Mrs Bonsu

Shelving dream of becoming a diplomat

After her first degree, she dreamed of joining Ghana’s Foreign Service and had even written the Public Services Commission examination. Then, unexpectedly, her path changed.

While awaiting for the results from the Public Services Commission, she came across an advertisement in the Daily Graphic announcing admissions into the School of Communication Studies. “It just jumped at me,” she recalls.

She applied and was admitted into the postgraduate communication programme — a decision that would eventually shape the rest of her career. Around the same time, she also came to an important personal realisation.

“Being a foreign service child meant moving every four years,” she says. “I realised I actually wanted stability. I wanted roots.” It was a powerful discovery for someone who had spent most of her life constantly moving.

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Building a career, rebuilding self

Her professional journey began in 1999 at Japan Motors where she worked as a Public Relations Officer. Four years later, she moved to Societe Generale Bank ⁠following the bank’s acquisition of SSB Bank.

Again, after four years, she joined GTBank Ghanaghana.gtbank.com⁠ as Head of Corporate Affairs. Looking back, she now finds humour in the pattern. “It was much later that I realised it reflected how often we moved during my father’s diplomatic postings,” she explains.

Eventually, motherhood changed her priorities and she decided to leave corporate life behind to focus more on family and pursue entrepreneurship.

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The decision initially frightened her. Walking away from the security of a monthly salary into the uncertainty of business was not easy. But with savings, planning and the support of her husband, she took the leap.

“He has been very supportive emotionally, financially and professionally,” she says.

In 2010, she established her own communications and advertising agency. The early years tested her patience and resilience. “It wasn’t easy because nobody really knew us at the beginning,” she says.

Her first breakthrough came when Koala Super Market gave her company an opportunity. From there, the business gradually expanded through referrals, relationships and consistency. Over the years, the company weathered economic downturns and survived the COVID-19 pandemic.

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“We’ve had ups and downs, but by God’s grace, we are still standing,” she says.

Trailblazer is birthed

Even while building her business, one thing remained constant; her desire to help others. Mrs Osei-Bonsu traces that instinct directly to her father. “My father was very big on education and helping females in particular,” she says.

For years, she quietly supported people through payment of school fees and personal assistance. But during the COVID-19 pandemic, after volunteering with several organisations, she felt compelled to formalise her efforts.

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This decision she explained led to the birth of Trailblazers in 2020. The organisation focuses on supporting women and children through education, skills development and empowerment initiatives. It has worked with schools, orphanages and vulnerable women, while also supporting organisations such as Street Girls Aid.

For her, philanthropy is not charity. It is responsibility even though she admits the work comes with challenges. “One of the biggest difficulties is funding,” she explains. “Many organisations are all trying to access limited resources.”

Yet despite the obstacles, she remains deeply committed to the mission and this is because for her, success was not measured only by titles or professional accomplishments, but by impact.

Coming full circle

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Today, she looks back on her journey with gratitude.

The young girl who once arrived in Jirapa angry, uncomfortable and homesick now understands that those difficult years shaped the woman she would become.

Her story is ultimately one of rediscovery — a journey back to identity, purpose and service. “I now understand why my father insisted so much on where we came from,” she says.

And perhaps that is the most powerful lesson of all: sometimes the roots we resist the most are the very ones that anchor our lives.

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By Cliff Ekuful

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Inside Nima: Faith, culture, life in Accra’s vibrant community

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Nima Market
Nima Market

Long before Accra fully wakes, Nima is already alive. From dawn, the call to prayer rises across the community as worshippers move quietly through narrow streets toward nearby mosques. Not far away, market women arrange tomatoes, onions, pepper, and smoked fish on wooden tables, while vendors prepare warm bowls of Hausa koko for workers starting their day early.

National mosque

This is Nima, one of Accra’s oldest, busiest, and most culturally vibrant communities.

For residents, Nima is more than a place. It is identity, family, struggle, faith, and survival woven tightly into everyday life. It is a community where life is shared and survival is collective.

Nima traces its roots to the colonial era, when migrants from northern Ghana and neighbouring West African countries settled in Accra in search of work and opportunity. Many arrived with little, but over time built a strong and closely knit community shaped by hard work, faith, and mutual support.

The origin of the name Nima is widely debated. Some link it to the Ga language, where “Nii” refers to a king and “mann” to a city, loosely interpreted as “city of the king.” Others trace it to the Arabic word “Ni’ma,” meaning “blessings,” reflecting the community’s strong Islamic influence.

Regardless of its origin, Nima remains one of Ghana’s largest and oldest Zongo communities, with roots stretching back to the 19th century.

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By Esinam Jemima Kuatsinu

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