Prior to the detection of gravitational waves, most black holes (excepting supermassive ones) were discovered through X-ray studies.From the figure below, what is different about the black holes detected through gravitational waves, and why might this be the case? 
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The process of building and maintaining relationships with people in one's industry or profession to further one's career or business interests.
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The act of looking for employment, through various means including online job boards, networking, or direct application to companies.
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