Back in March I took a Science Journalism workshop with Ivan Semeniuk. We learned how to write about science for the public, the 5 W's etc. and how to interview a scientist about their work. We were also assigned to write our own stories. What follows is my submission based on interviews with Mubdi and Ilana.
It takes a dust buster to reveal Milky Way’s massive star clusters
Eleanor Louson
Our Galaxy was hiding its biggest and brightest star forming regions. A new paper for the Astrophysics Journal reveals how the authors cut through the dust and located massive clusters of stars in our own backyard.
Secret clusters in our Galaxy
Mubdi Rahman and coauthor Norman Murray, a professor from the Canadian Institute for Theoretical Astrophysics at the University of Toronto, wanted to measure the rate at which stars form in our Galaxy, “one of the critical measurements about our own Galaxy that we take for granted” says Rahman. In the process of doing this, they found the massive star forming regions, clusters of over ten thousand stars, which trigger the birth of additional star clusters nearby.
“Scientists in general have thought for the longest time that super star clusters were the strange, rare objects that existed far, far away from us” explains Rahman, a Ph.D. candidate in Astronomy and Astrophysics at the University of Toronto. “We're showing that there are more than a handful in our own Galaxy.”
Cutting through the dust
The problem was that the disk of own Galaxy was too dusty for any of these massive clusters to be detected in visible light. “Our Galaxy is incredibly dusty. This has been the problem in trying to look for these kinds of clusters - we have to look through the dust that blocks the light” says Rahman. Scientists have located these clusters in other Galaxies, particularly in those they call starburst galaxies, where stars form at a rate about 100 times more than in the Milky Way.
Rahman and Murray used radio wave and infared light telescopes to mitigate the effects of the dust and find the star forming regions closer to home. “Both of these have an easier time getting through the dust” according to Rahman.
First, they used data from a space telescope, the Wilkinson Microwave Anisotropy Probe (WMAP), to find the rough evidence of massive clusters. Ironically, data from that probe about our own Galaxy is usually discarded, because the probe's main goal is to focus on the background noise, a remnant of the early universe. “It’s very cool because they used observations originally meant to be used on the cosmic microwave background radiation, and they used data on our Galaxy that used to be taken out” says Ilana McDonald, a graduate student at the Canadian Institute for Theoretical Astrophysics who was not involved in this research. Since Rahman and Murray were looking for clusters in our own Galaxy, they followed their WMAP hunches using a survey of the majority of the plane of our Galaxy from the much more powerful Spitzer infared telescope.
Bigger clusters mean bigger stars
When it comes to finding big stars in a cluster, it’s the more, the merrier. “Just like with people, the bigger the group you look at, the more likely you are to find someone who is 7 feet tall” explains Rahman. Big clusters tend to contain big stars, and those big stars are exciting to astrophysicists. They live large, producing strong winds of gas from their surfaces, release the most energetic light – and die young in a blaze of glory. The biggest stars last only a few million years, whereas our Sun will eventually live for about 10 billion years.
Rahman and Murray found a few dozen new young clusters, including a few containing over 100 000 stars. They have exciting work ahead of them – looking at the specific stars in the clusters they detected in our Galaxy. “These clusters will be a great laboratory to figure out what the maximum mass a star can be” says Rahman.
For now, their work can inspire other astrophysicists to take a closer look in our own backyard. “There are vast riches in the depths of our Galaxy that are hidden by the copious amounts of dust” says Rahman. And even though he designed a method to find large, bright clusters of stars, Rahman thinks that similar creativity could go a long way towards detecting what else the Milky Way has hidden under all that dust.
Rahman and Murray’s paper, Massive Star Forming Regions in the Galaxy using the Spitzer GLIMPSE Survey, will be submitted to the Astrophysical Journal later this week.
It takes a dust buster to reveal Milky Way’s massive star clusters
Eleanor Louson
Our Galaxy was hiding its biggest and brightest star forming regions. A new paper for the Astrophysics Journal reveals how the authors cut through the dust and located massive clusters of stars in our own backyard.
Secret clusters in our Galaxy
Mubdi Rahman and coauthor Norman Murray, a professor from the Canadian Institute for Theoretical Astrophysics at the University of Toronto, wanted to measure the rate at which stars form in our Galaxy, “one of the critical measurements about our own Galaxy that we take for granted” says Rahman. In the process of doing this, they found the massive star forming regions, clusters of over ten thousand stars, which trigger the birth of additional star clusters nearby.
“Scientists in general have thought for the longest time that super star clusters were the strange, rare objects that existed far, far away from us” explains Rahman, a Ph.D. candidate in Astronomy and Astrophysics at the University of Toronto. “We're showing that there are more than a handful in our own Galaxy.”
Cutting through the dust
The problem was that the disk of own Galaxy was too dusty for any of these massive clusters to be detected in visible light. “Our Galaxy is incredibly dusty. This has been the problem in trying to look for these kinds of clusters - we have to look through the dust that blocks the light” says Rahman. Scientists have located these clusters in other Galaxies, particularly in those they call starburst galaxies, where stars form at a rate about 100 times more than in the Milky Way.
Rahman and Murray used radio wave and infared light telescopes to mitigate the effects of the dust and find the star forming regions closer to home. “Both of these have an easier time getting through the dust” according to Rahman.
First, they used data from a space telescope, the Wilkinson Microwave Anisotropy Probe (WMAP), to find the rough evidence of massive clusters. Ironically, data from that probe about our own Galaxy is usually discarded, because the probe's main goal is to focus on the background noise, a remnant of the early universe. “It’s very cool because they used observations originally meant to be used on the cosmic microwave background radiation, and they used data on our Galaxy that used to be taken out” says Ilana McDonald, a graduate student at the Canadian Institute for Theoretical Astrophysics who was not involved in this research. Since Rahman and Murray were looking for clusters in our own Galaxy, they followed their WMAP hunches using a survey of the majority of the plane of our Galaxy from the much more powerful Spitzer infared telescope.
Bigger clusters mean bigger stars
When it comes to finding big stars in a cluster, it’s the more, the merrier. “Just like with people, the bigger the group you look at, the more likely you are to find someone who is 7 feet tall” explains Rahman. Big clusters tend to contain big stars, and those big stars are exciting to astrophysicists. They live large, producing strong winds of gas from their surfaces, release the most energetic light – and die young in a blaze of glory. The biggest stars last only a few million years, whereas our Sun will eventually live for about 10 billion years.
Rahman and Murray found a few dozen new young clusters, including a few containing over 100 000 stars. They have exciting work ahead of them – looking at the specific stars in the clusters they detected in our Galaxy. “These clusters will be a great laboratory to figure out what the maximum mass a star can be” says Rahman.
For now, their work can inspire other astrophysicists to take a closer look in our own backyard. “There are vast riches in the depths of our Galaxy that are hidden by the copious amounts of dust” says Rahman. And even though he designed a method to find large, bright clusters of stars, Rahman thinks that similar creativity could go a long way towards detecting what else the Milky Way has hidden under all that dust.
Rahman and Murray’s paper, Massive Star Forming Regions in the Galaxy using the Spitzer GLIMPSE Survey, will be submitted to the Astrophysical Journal later this week.
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