Queen researchers are leading the discovery of two possible polar ring galaxies.
A group of international astronomers, including researchers from Queen’s University, have identified two possible polar ring galaxies, according to results published in the journal Science on September 13th. Royal Astronomical Society Monthly Notices.
Queen’s University researchers Nathan Degg and Christine Speckens (Physics, Engineering Physics, Astronomy) led the analysis of data obtained using a telescope owned and operated by Queen’s University . CSIRO, Australia’s National Science Agency. Observing sky maps of hydrogen gas in more than 600 galaxies as part of his ASKAP radio telescope at CSIRO wallaby questionnairethey identified two that may be polar ring galaxies, a type of galaxy that exhibits rings of stars and gas perpendicular to the main spiral disk.
“Polar ring galaxies are some of the most spectacular galaxies in the universe. These discoveries suggest that between 1 and 3 percent of nearby galaxies may have gaseous polar rings. , which is much higher than suggested by optical telescopes.”
— Dr. Nathan Degg, researcher in the Department of Physics, Engineering Physics and Astronomy, Queen’s University, Canada, and lead author of the study
Historical background and meaning
This is not the first time astronomers have observed a polar ring galaxy, but it was observed using the ASKAP telescope at CSIRO’s Murchison Radio Astronomy Observatory, Inyarimanha Yirgali Bundara, in Western Australia’s Wadjari Yamatji Country. It’s my first time.
These new gas-only detections suggest that polar galaxies may be more common than previously thought.
“These results very well demonstrate the tremendous value of mapping the sky deeper and wider than ever before. This is serendipity at its finest. We never expected to find anything. I found something I didn’t have.”
— Dr. Christine Speckens, Professor, Department of Physics, Engineering Physics and Astronomy, Queen’s University, Canada (concurrent appointment from the Royal Military College)
Understand how galaxies evolve
Exploring the structure of the polar ring in more detail could help us better understand how galaxies evolve. For example, one of the main hypotheses explaining the origin of polar rings is mergers, where larger galaxies “swallow” smaller galaxies. If polar ring galaxies are more common than previously thought, it could mean that these mergers occur more frequently.
In the future, polar galaxies could also be used to improve our understanding of the universe, and could even be applied to the study of dark matter. It is possible to use the polar ring to study the shape of the host galaxy’s dark matter, which could lead to new clues about the mysterious nature of the elusive matter.
“These new ASKAP observations reveal surprising ring-like structures around seemingly ordinary spiral galaxies, suggesting that gas accretion through interactions with gas-rich companion galaxies was previously thought to be WALLABY will be a great resource for uncovering more such systems in the future. ”
— Professor Lister Staveley-Smith, Wallaby Co-Principal Scientist and Interim Executive Director. Iqral
Visualization of polar galaxies
Jayan English, a member of the Wallaby research team and an expert in astronomical imaging at the University of Manitoba, combined optical and radio data from a variety of telescopes to create the first images of these gaseous polar galaxies. created. First, optical and infrared data from the Subaru Telescope in Hawaii provided images of the galaxy’s spiral disk. Next, he will detect atomic hydrogen emission from about 500,000 galaxies, based on data obtained from his WALLABY survey, an international project using his ASKAP radio telescope at CSIRO. Ring added.
“Our ASKAP radio telescope is delivering a huge amount of data, and we are ready for it. A full WALLABY with ASKAP will deliver over 200,000 hydrogen-rich galaxies, It also includes many unusual objects such as polar rings, which can be used to investigate the shape and distribution of dark matter halos.”
— Dr. Barber Kolibalski, CSIRO Senior Principal Researcher
The creation of this and other astronomical images are all composites because they contain information that our eyes cannot capture. In this particular case, a cold hydrogen gas component invisible to the human eye is seen in the radio ‘light’ using CSIRO’s ASKAP. The subtle color gradations in this ring represent the orbital motion of the gas, with the purplish hue at the bottom tracking the gas as it moves toward the observer, and the top moving away. The radiation from the rings was separated from the radio radiation emitted by the galaxy’s disk using virtual reality tools, in collaboration with Professor Tom Jarrett (University of Cape Town, South Africa).
“I am excited to be working with such a diverse and collaborative team. Now we have the rich velocity data, so we can assign multiple colors to this composite to subtly convey the movement happening within the polar ring. The dance and choreography of the gases is beautiful, and the gas The movement of the galaxy gives us clues about how galaxies evolve over time.”
— Dr. Jayan English, Department of Physics and Astronomy, University of Manitoba
More than 25 global collaborators from Canada, Australia, South Africa, Ecuador, Burkina Faso, Germany, China and more collaborated to analyze data from the first publicly available data from the WALLABY study, resulting in a newly published paper. I was born.
The next step for the research team is to confirm the polar ring galaxy discovery through additional observations using a variety of telescopes, including the MeerKAT radio telescope in South Africa.
“One of the most exciting outcomes of large-scale surveys like Wallaby will be to scan large swaths of the southern sky to conduct the largest census of neutral atomic hydrogen ever conducted.” It’s all about discovering the unexpected. These rare galaxies with beautiful gas rings are perfect for this example. ”
— Barbara Catinella, assistant professor, WALLABY co-principal investigator and co-author of the study. ICRAR, University of Western Australia
Reference: “WALLABY Pilot Survey: Potential Polar Ring Galaxies NGC 4632 and NGC 6156” N Deg, R Palleske, K Spekkens, J Wang, T Jarrett, J English, X Lin, J Yeung, JR Mould, B Catinella, Denes H, A Elagali, B -Q Four, P Kamfis, BS Kolibalski, K Lee-Waddell, C Murgeshan, S Oh, J Lee, P Serra, T Westmeyer, OI Wong, K Becchi, A Bosma, C Carignan, BW Holverda and N Yu, September 13, 2023; Royal Astronomical Society Monthly Notices.
DOI: 10.1093/mnras/stad2312