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Jacqueline Antwi-Danso …NSERC Banting Postdoctoral Fellow at the David A. Dunlap Department for Astronomy & Astrophysics
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.
“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.
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.
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.
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
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.
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.
“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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From passion to plate: Chichi Yakubu’s culinary journey
Driven by her personal weight loss journey and passion for healthy eating, Chichi Yakubu has carved a niche for herself in the culinary industry.
Her dedication and commitment has turned her business, NyoNyo Essentials, to one of Ghana’s most sought-after catering companies in the country.
Born to a Nigerian father and a Ghanaian mother, Chichi grew up in a family of passionate women at Mamprobi Polytechnic.
Her mother, an avid cook, started a small catering business, which Chichi helped manage during vacations.
“From upper primary through to Junior High School, I will close from school to go and help my mother at her small food stand at Sakaman to do the dishes after her customers had eaten.
Her mother was known for her special dough Banku with Okro soup. Her small food joint expanded to become a chop bar where she worked at when on vacations.
She acknowledged that, “this early exposure to entrepreneurship sparked my interest in the culinary industry.”
After her university education, Chichi embarked on a weight loss journey, which led her to explore the culinary side of things.
According to Chichi, her weight loss journey began after she realised in her late teens her family struggle with weight.
“I wasn’t going to just allow it but someway, somehow, I started gaining so much weight in my early twenties and I decided to take action by changing my lifestyle by eating healthy and exercising. That’s what got me interested in meal prepping which eventually became my side hustle,” she narrated.
Chichi later discovered the business potential of healthy food and decided to pursue it. Also her friends were curious about her weight loss strategies, which inspired her to offer meal-prep services at a fee.
With a bold vision and determination, Chichi started small, offering sandwiches, salads, and smoothies.
Leveraging social media marketing, she reached a wider audience and grew her business rapidly.
Today, Chichi is the Chief Executive Officer of Nyonyo Essential, a business that has expanded to cater for weddings, parties, and corporate events with her team providing excellent service, and word-of-mouth referrals have helped her expand her client base.
Again, Chichi has also opened kitchen centres in selected areas, providing healthy food options to Ghanaians.
She mentioned that, her mother has been her number one supporter saying “she had the blue print handed down to me. I started my business in her kitchen, and she also spared me some of her workers when the new people I had hired didn’t show up.
“My then boyfriend and now husband believed in me even when I was not sure to do it full time as I was in corporate Ghana and not doing bad.”
Chichi said one of her biggest challenges was staff retention, adding that she was of the opinion that the work itself was not much of a challenge but the people.
The other thing was stereotyping, saying that, “some years back people look down on food business operators, we were not regarded as professionals with others assuming we are school dropouts or just people who don’t know what we are about.”
But I was determined to change that narrative by handling work with the outmost professionalism, which I have since the beginning of my weight loss journey in 2014.
Chichi is motivated by her faith in Christ, her passion for entrepreneurship, and her commitment to empowering women.
As a wife, mother, and business owner, she strives to create a balance that reflects her vision of an all-rounded woman.
In business, she emphasised, her drive comes from a deep love for the hospitality industry and a desire to help others succeed through the business of catering by NyoNyo, saying that, “My belief that Jesus is Lord guides my decisions, ensuring that integrity, excellence, and purpose shape both my life and business.”
She urged young people, especially young women, who are just starting out in their careers or entrepreneurial journeys to believe in themselves, trust God’s timing, and be willing to put in the work.
Moreover, she said “success does not happen overnight, so stay consistent, be patient, and keep learning. Surround yourself with the right people, mentors, peers, and a support system that challenges and encourages you.”
“Opportunities don’t pause for perfection. While we overthink, others take action. Start where you are, with what you have. The world moves fast—so should we,” – Chichi Yakubu advised
She again added that women should embrace their multifaceted roles without guilt saying “you can be an entrepreneur, a wife, a mother, and a sister’s keeper all at once. Most importantly, stay true to your values and never compromise on integrity. Let your journey reflect both purpose and excellence.”
Chicihi loves to spend quality time away from the noise of life in new places or go on an adventure with her family and friends.
She is a product of Christian home school, Okuapeman secondary, Central University College and Harvard University.
By Jemima Esinam Kuatsinu
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Patriotism, sacrifice and service — the veterans’ perspective
For men and women with battlefield experience, patriotism, sacrifice, and service are not just abstract ideas, they are lived experiences deep-rooted in hardship and sustained endurance in the line of duty.
Such lifelong duty goes beyond the uniform to include the values of duty, honour, and commitment, long after active military service.
Such has been the life of Ex Lance-Corporal Wisdom Edmund Kudowor, a 97-year-old World War Two (WWII) Veteran, who volunteered for recruitment in 1943 at the age of 15.
He was to be trained and enrolled as a soldier and tradesman for the Artisan Work Company of the then Gold Coast Regiment.
Though looking frail currently after a few days of head surgery, the ex-serviceman’s ability to recall his past experiences was exceptional.
Ex-Lance-Cpl Kudowor lived in an era that saw many young Africans recruited and conscripted to fight for their colonial masters in a war that ravaged half of Europe and claimed almost 85 million lives.
In a brief yet straight to the point interaction with the Ghana News Agency, he expressed no regret in volunteering, despite the imminent danger and harrowing stories about WWII back then.
More surprising was his nonchalant attitude towards the fact that he was not put on pension immediately after service. He expressed no bitterness nor pain.
He returned to the Gold Coast in 1946 after four years of service without any benefits, not until two years ago when he began receiving an annually paid British grant, which was recently increased to 1,350 pounds sterling.
Though the grant did not match the sacrifice, “it is still better than nothing,” he said. Despite his past experiences, the old veterans’ patriotism, sacrifice and service did not wane after his return in 1946, at age 18, to the then Gold Coast.
He gained scholarship to further his education (both home and abroad) and with the knowledge acquired, he served his country for almost half a century, first as a pupil teacher, and rising to become the Headmaster of the Kpando Technical Institute. He headed other educational institutions and retired as a civil servant.
The veteran was not happy about the decline in patriotism and sacrifice, especially among young people in contemporary Ghana.
Listening attentively due to a hearing challenge, the frail-looking veteran pointed to the attitude of the current generation, most of whom were unwilling to go the extra mile to support their country.
He expressed worry over their focus on immediate gains and monetary rewards for little services rendered.
His observation was corroborated by Captain Ben Edmund Duah (Rtd), a veteran, who began his service with the Field Engineer Regiment soon after being commissioned at age 24 as a young officer in the early 1970s.
The retired Army Captain, who once served with the Delta Company of the Five Battalion of Infantry (5BN) among other positions, said: “Patriotism is non-existent in today’s Ghana, unlike our time when we took pride in openly exercising these values.” He, however, did not entirely blame the youth for not exhibiting such traits.
Capt. Duah (Rtd) attributed the seeming non-patriotism by the youth to the struggles they see the veterans go through just to survive, after sacrificing for humanity.
The needs and concerns of patriots and forerunners, particularly veterans in Ghana, were largely unmet, compared to other countries, he said.
“The veterans brought honour to our colonial masters and by extension to Ghana. They were not given what they were promised. Right now, the British Government gives them some support and that is what sustains a lot of them.” Captain Ben Duah stressed the urgency for the country to pay more attention to the concerns and needs of veterans.
“We should see them as people who voluntarily decided to sacrifice their lives for us. If anybody does this for you, you should be fair enough to look at his interest…these are people who have devoted their lives to save us, therefore we should be nice to them in the form of caring for them,” he noted.
When asked for their opinion on many of the youth trying to seek greener pastures abroad due to their lack of confidence in the economy, Capt Duah and L/Cpl Kudowor both agreed that Ghana was still worth sacrificing for, despite the challenges.
Captain Duah, who served during an era awash with military coups d’etats, urged Ghanaians to respect, recognise and be willing to support veterans because government could not shoulder the responsibility alone.
“Citizens should realise that these are people who, some time ago, in their youthful years, sacrificed their precious lives to save others…We expect that as veterans, people will respect and admire them for their values and bravery,” he said.
“I will advise the youth to utilise existing opportunities as a means to serve Ghana. Service to the country, I believe, should be the youths’ primary goal”, Ex L/Cpl Kudowor said.
The two justified the continuous celebration of Veterans Day on the 28 of February as a step in the right direction.
This serves as a platform for the youth to learn about the three values of patriotism, service and sacrifice, the history behind the celebration and the need to respect veterans.
On February 28, 1948, Veterans of World War II, who had fought with the Gold Coast Regiment of the Royal West African Frontier Force, organised a peaceful demonstration, marching to the Christainborg Castle at Osu in Accra, the capital of the Gold Coast, to hand a petition to the colonial governor, demanding their end of war benefits, which they had been promised.
Before reaching the castle, the veterans were ordered to disperse by the colonial police chief. When they refused, he opened fire on them, instantly killing three of the ex-servicemen – Sergeant Adjetey, Corporal Attipoe, and Private Odartey Lamptey.
The 28 February Crossroads Shooting is commemorated every year to honour the veterans for their sacrifice to the country.
—GNA
