How an Astronomer Is Trying to Solve Mysteries From Far-Off Galaxies

“We want to know why these galaxies are so luminous. What is the source – is there a big central nucleus at the centre,” says Seema Pooranchand

Seema Pooranchand at UoH. Credit: The Life of Science

Seema Pooranchand at UoH. Credit: The Life of Science

Hyderabad: For scientists, the period after their PhD is crucial. They are fresh out of the lab they spent the last four or more years in, motivated by new discoveries and published papers. Their career is at a high, and the skill and aggression with which they capitalise on this momentum will likely dictate their ascent in academia.

In 1994, twenty-eight-year-old astronomer Seema Pooranchand was in the same boat. She had just completed her PhD from Physical Research Laboratory (PRL), a space research institute in Ahmedabad. Things were looking up for her. Having recently gotten married to her colleague at PRL, she moved to the US where he had a project with NASA’s JPL and she had secured a research position in one of the world’s most famous sites for astronomy research, California Institute of Technology, or Caltech as it is popularly known. But after an encouraging stint there for two years, things didn’t just slow down for Pooranchand, they stood still. Some unexpected challenges in her personal life forced her out of academia for the next 18 years.

In 2015, Pooranchand, now nearing fifty, made a quiet return, aided by a government fellowship for women scientists. I met her at a somewhat dingy office room in the University of Hyderabad, where she and her husband now work.

University of Hyderabad. Credit: The Life of Science

University of Hyderabad. Credit: The Life of Science

In a galaxy far, far, away

These days, Pooranchand and her trusty laptop scour through data that comes from the Spitzer space telescope, trying to answer some fundamental mysteries in far-off galaxies. “Specifically, I study ultra-luminous galaxies,” she said. These galaxies emit 10^12 to 10^13 times more light than the sun (or 100 to 1,000 times more than the Milky Way), and astronomers are still not sure why. “We want to know why these galaxies are so luminous. What is the source – is there a big central nucleus at the centre, or is there too much star formation happening?”

An ultraluminous galaxy named IRAS 14348-1447. Credit: Wikimedia Commons

An ultraluminous galaxy named IRAS 14348-1447. Credit: Wikimedia Commons

The ‘big central nucleus’ that she talks about is technically called an active galactic nuclei (AGN). The extreme radiation from an AGN is believed to be from a phenomenon called a super-massive black hole. But Pooranchand’s hunch is that it’s not AGN that is the source of her ultra-luminous galaxies but a rapid evolution of stars – that is, starburst activity caused by galactic collisions (the merging of two galaxies).

The Spitzer Space Telescope was launched by NASA in 2003. Space telescopes are able to observe objects in the distant parts of the universe that are invisible to optical telescopes on Earth. Spitzer’s camera enabled it to see objects in space that emit infrared light (as opposed to visible light, which our eyes and optical telescopes can see). This makes Spitzer data ideal for Pooranchand because most of the light emitted by her ultra-luminous galaxies is infrared.

In addition to the camera, Spitzer also has an instrument called the Infrared Spectograph that takes in the infrared light coming in from galaxies and splits them into light of different wavelengths – just like a prism splits white light into a rainbow. This phenomenon is represented on a graph with peaks and pits (see image). Since each element has a signature wavelength, it is possible to detect the elements and molecules that make up a galaxy from its spectrum. Several software have been built to computerise this detection.

Spitzer space telescope – an artist’s rendering. Credit: NASA JPL

Spitzer space telescope – an artist’s rendering. Credit: NASA JPL

This is the sort of data that Pooranchand deals with. She is on the lookout for a class of compounds called poly aromatic hydrocarbons (PAH). PAH is known to be present in high levels when stars form and in low levels in the presence of an active galactic nucleus (AGN). Hence, it can be used as a marker-compound to indicate starburst activity. Her sample consists of 500 ultra-luminous galaxies.

Already, evidence of PAH in her sample is trickling in. “I’m finding that many show PAH signature. I’m looking for a particular wavelength of 7.7 microns. If there is strong emission there, PAH must be present. But I need more statistical proof.”

Credit: The Life of Science.

Credit: The Life of Science.

Credit: The Life of Science

Credit: The Life of Science

Like most astronomical research, the results of Pooranchand’s project will help us understand our own better. “There is no direct application but ultimately we want to know how our galaxy was formed, did it ever merge with another, and what,” she said with a smile, “will the end be like…”

Moving and staying out of her comfort zone

Pooranchand was educated in a convent school in Hyderabad. Being the only girl among four children, she grew up very protected, studious and shy. Like most science students in high school, she too tried to get into an engineering college, but there were only a few colleges and the competition was too fierce. She decided to pursue her BSc in Physics at the local women’s college instead.

It was when she procured admission in Roorkee University (now IIT Roorkee) that Pooranchand and her family were first confronted with the idea of her leaving home. “It was not easy for them to send me to a hostel. Moreover, my father was not a big officer or anything, and he had four children to look after. But he had an aspiration for me, so he sponsored me to go pursue my MSc.”

Finally out of her comfort zone, Pooranchand was able to shed some of her timidity and plunge into the world of research. She went on to secure a PhD position at the prestigious PRL in Ahmedabad, and her parents were thrilled. Her mother had even accompanied her to the interview. Pooranchand is unflinching in her belief that her achievements would not have happened if not for their support. “I had a classmate in BSc. She was quite good academically and got in to PRL but her mother did not allow her to go. The same thing happened with another classmate from Kanpur, who was the gold-medallist in my MSc class,” she recalled. “Even when my father suddenly died while I was in Roorkee, my family did not stop me from continuing with studies. I am thankful that my parents never said come back, get married…It helps ladies to have that encouragement.”

Persistence and a PhD

Pooranchand joined PRL in 1987 and completed her PhD in 1994. Seven years was a bit longer than she’d expected it to take, but the topic of her thesis was a difficult one. “I had taken up the challenge of developing an instrument to study galaxies. I had to use a special detector that was new to our lab,” she said. Another obstacle for her was that there were no telescopes in PRL at that time. “I had to study galaxies but most are too far and too faint. To observe the Orion Nebula, I needed to use the telescope present in Mount Abu. Once while on my way there, there was a lot of rain, and my instrument got spoilt. We had to send it back to England for repair and then wait to get it back. All of this took time.”

Seema Pooranchand at PRL. Credit: The Life of Science

Seema Pooranchand at PRL. Credit: The Life of Science

At the time she joined PRL, there were only two other women doing their PhDs. One of them was studying theory and the other was a day-scholar, so Pooranchand often did not have female company while travelling to make her observations. In terms of safety, she saw nothing amiss. The only disadvantage, she said, was that she found it difficult physically to carry the instrument alone. Her colleagues were mostly helpful but having to ask for assistance can be a hindrance. “Maybe I could’ve done more observations on my own if I didn’t have to,” she reflected.

There was a more immediate cause of anxiety for Pooranchand. “I was almost always alone in the girls’ hostel and trips from and to the lab in the night were a problem. I should tell you, there was physical abuse from strangers on two-wheelers. They used to push and touch and all.” Again, the harried PhD student had to turn to friendly male colleagues for safety and company.

It was around this time that she made friends with a senior of hers, Syed Maqbool Ahmed, who would eventually become her husband. Pooranchand said that Syed, also from Hyderabad, was a big help and being attached to him made it safer for her to walk out at night.

Challenges at home

Pooranchand and Syed got married shortly before she submitted her completed thesis. She was aware that when they chose to have children, she would have to sit out for a while, but when their daughter was born almost two months premature, Pooranchand’s plans went haywire. “The doctor said we need to take lots of care because her lungs were weak, and there were many other complications. So, I could not take up any academic work or job,” explained Pooranchand. A few years later, their son was born and he, too, had some health problems. At the age of seven, their daughter was diagnosed with muscular dystrophy – a genetic disorder that is marked by a progressive wasting away of muscles.

The situation hit the couple especially hard because they had no support from either of their parents. “Ours was an inter-religion marriage, so there was no support from the families. We had a court marriage in Ahmedabad – my brothers came and his brother and mother came, but they did not accept us completely. Since I did not have a mother or mother-in-law to come and stay with me, I could not leave my children at home and work like most people. Even socially, there was not much help. There were many times we had to rush the children to the hospital at night.”

The difficulty of a re-entry

Meanwhile, Pooranchand was trying her best to cling on to her career. “The thing is, in India we expect ladies to take care of the house. I was also expected to do so. Maybe I could have done some private research out of own interest, but because of this I could not get the time. It’s a bit disappointing sometimes.”

Pooranchand coached students and gave public lectures to school and college students to motivate them towards astronomy whenever she could. But as the years sped by, the prospect of getting back to research seemed to be getting dimmer. None of her job applications were making the cut; rarely was she even called for an interview. “I found that we are expected to have continuity in research and papers, despite the break. They ask us what we have done during the gap years, and unless it is something professional, we are not considered,” she said.

At some interviews, Pooranchand admits to having been caught off-guard by questions that had nothing to do with her research but were so basic that she had trouble answering them. The jobs she was offered paid very poorly. “Local private colleges preferred their own MSc candidates to someone from the outside like me, even though I have a PhD and experience at PRL and CalTech. Sometimes, it is a way for them to compromise on salaries. They are not ready to pay PhDs.”

The breakthrough she needed

Just as her confidence was waning, Pooranchand’s former supervisor at PRL moved to Hyderabad. He urged her to apply for a Department of Science & Technology fellowship for women scientists. The scheme, called Women Scientists Scheme-A (WOS-A), was started to bring back women scientists and technologists between the age group of 27-57 years into mainstream science after a break.

Though the scheme was meant for scientists who had taken a break, Pooranchand knew that her 18-year break set the odds against her. But she kept her hopes up. It took almost a year to prepare her proposal and finish the application process, but Pooranchand was elated to find that she made it. Her face lit up in recollection: “It was a very positive thing for me. The committee who interviewed me was very excited to hear about my long break. In that batch, most applicants had breaks of just three years. They said this was a great thing.”

The fellowship came at the right time for Pooranchand. The amount of 30 lakh rupees spread over three years required her to have a host university, and University of Hyderabad agreed to give her an office. Things have somewhat stabilised at home, too. Her daughter, 18 years old today, studies health psychology in the same university. Since all her data and the software are on her laptop, Pooranchand can work from home when needed.

As welcome as such schemes are, Pooranchand wishes the red tape was less tedious. Five months into her second year, she has not received the second installment of her grant money. “I called them up but they say they have not yet updated my file. I’m trying to continue my work, but it’s disappointing. We work so hard to get it but I heard that this happens with DST. Since my husband is working, I’m able to manage. I want to request them to look into this so that my research can go on smoothly.”

This piece was originally published by The Life of Science. The Wire is happy to support this project by Aashima Dogra and Nandita Jayaraj, who are travelling across India to meet unsung women scientists.