The York University Magazine

Fall 2015

The alumni magazine of York University

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velocities up to 20 per cent of the speed of light. These winds can affect the galaxy surrounding the quasar, and are an active topic of current research in astronomy, including my own." Study co-author Niel Brandt, Distinguished Research Pro- fessor at Penn State University, explains further: "Just like you can use the Doppler shift for sound to tell if an airplane is moving away from you or toward you, we use the Doppler shift for light to tell whether the gas in quasars is moving away from us or toward us. In these objects, some gas is doing both, though most of it is moving away from us." Quasars like these were not predicted by models of quasar winds, and astronomers weren't on the lookout for them. "No one realized what these objects were until one day, while looking for something else, I spotted one which could only be explained as having gas around the quasar moving away from us at very high velocity," says Hall. Such infalling gas is believed to occur in only about one out of 10,000 quasars, and only 17 cases are known. This discovery is detailed in a peer-reviewed paper in the journal Monthly Notices of the Royal Astronomical Society, published by Oxford University Press. Given the strong gravity of black holes, and the fact that there is nothing else unusual about these particular quasars, why isn't gas falling into more of them? "It could be that the gas moving away from us is not [actually] falling into the black hole but is orbiting around it, just above the disc of hot gas, and is very gradually being pushed away from the black hole," explains Hall. "A wind like that will show gas moving both toward us and away from us." Due to this discovery, models of quasars and their winds need to be revised to account for these rare cases, he says. To help understand what revisions are required, Hall, his students and his colleagues are continuing to observe these quasars further, using the Canadian and American access to the Gemini North telescope in Hawaii. l A C E N T U RY AG O, the average Canadian lifespan was 60 years. Today, most of us can expect to live at least 20 years longer. In addition, the baby boom generation, comprising 30 per cent of the Canadian population, is now entering retirement age – causing many to worry about the potential ramifications. But no two people retire the same, suggests Thomas Klassen, a professor in York University's Department of Political Science and School of Public Policy & Administration. As the arc of our individual and collective lives continues to change, he says, so too will the experience of retirement. Klassen has written extensively on retirement and income security for older Canadians. In his latest book, Retirement in Canada, he tackles a myriad of myths and misconceptions about retirement and offers insights into how retirement is changing as the baby boom generation ages – for individuals, families, employers, policy-makers and Canadian society at large. "I wanted to counter the various doomsday scenarios that are being put forward," says Klassen, "including that the retiring baby boomers are causing the implosion of public health care and pensions, and taking jobs away from young people. A more balanced account seemed important, rather than the sensational journalistic stories or those from financial advisors, which too often scare readers." What does Klassen hope the takeaway will ultimately be? "That readers understand that retirement, both for individuals and for society, is a gradual process." l TSUNAMI Worried about retirement? Don't be Fall 2015 The York University Magazine 11

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