{"591992":{"#nid":"591992","#data":{"type":"news","title":"In Search of the Goldilocks of Black Holes","body":[{"value":"\u003Cp\u003EBlack holes can be divided into three classes according to mass. On the low end are those with masses 10 times that of the sun. Examples are the two black holes whose merger generated the \u003Ca href=\u0022http:\/\/www.news.gatech.edu\/2016\/02\/11\/gravitational-waves-detected-100-years-after-einsteins-prediction\u0022\u003Efirst gravitational wave to be detected\u003C\/a\u003E, by \u003Ca href=\u0022http:\/\/www.ligo.org\/\u0022\u003Ethe LIGO Scientific Collaboration\u003C\/a\u003E (LSC), an international team including researchers in the School of Physics\u0026rsquo; \u003Ca href=\u0022http:\/\/www.cra.gatech.edu\u0022\u003ECenter for Relativistic Astrophysics\u003C\/a\u003E (CRA). LIGO stands for Laser Interferometer Gravitational-Wave Observatory, a facility based in the U.S.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EOn the high end are black holes that are a million times as massive as the sun. \u003Ca href=\u0022https:\/\/www.nasa.gov\/multimedia\/imagegallery\/image_feature_1846.html\u0022\u003EEvidence for them comes from NASA images\u003C\/a\u003E.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFor the Goldilocks black holes, with masses in between, no hard proof exists to date. \u003Ca href=\u0022https:\/\/www.nasa.gov\/feature\/goddard\/astronomers-identify-a-new-mid-size-black-hole\u0022 target=\u0022_blank\u0022\u003EIndirect evidence\u003C\/a\u003E has been offered, but nothing unambiguous so far. A single detection can transform our understanding of the first stars in the universe.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAs it happens, LIGO has been designed to detect gravitational waves arising from collisions of midsize black holes. A \u003Ca href=\u0022https:\/\/arxiv.org\/pdf\/1704.04628.pdf\u0022\u003Erecent study\u003C\/a\u003E suggests that the Goldilocks of black holes may be uncommon. Analysis of LIGO data collected from September 2015 through January 2016 found no evidence for midsize black holes. However, the work enables scientists to estimate more accurately than ever before the abundance of such black holes.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe paper reports a \u0026ldquo;survey of the universe for midsize-black-hole collisions up to 5 billion light years ago,\u0026rdquo; says \u003Ca href=\u0022https:\/\/www.physics.gatech.edu\/user\/karan-jani\u0022\u003EKaran Jani\u003C\/a\u003E, a former Georgia Tech Ph.D. physics student who participated in the study. That volume of space contains about 100 million galaxies the size of the Milky Way. Nowhere in that space did the study find a collision of midsize black holes.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026ldquo;Clearly they are much, much rarer than low-mass black holes, three collisions of which LIGO has detected so far,\u0026rdquo; Jani says. Nevertheless, should a gravitational wave from two Goldilocks black holes colliding ever gets detected, Jani adds, \u0026ldquo;we have all the tools to dissect the signal.\u0026rdquo;\u003C\/p\u003E\r\n\r\n\u003Cp\u003EThe study was undertaken by hundreds of scientists worldwide belonging to LSC and \u003Ca href=\u0022http:\/\/public.virgo-gw.eu\/the-virgo-collaboration\/\u0022\u003Ethe Virgo Collaboration\u003C\/a\u003E, another international team observing gravitational waves from a facility in Italy. Georgia Tech scientists worked on \u003Ca href=\u0022https:\/\/arxiv.org\/pdf\/1704.04628.pdf\u0022\u003Ethe paper\u003C\/a\u003E in close collaboration with colleagues from the \u003Ca href=\u0022http:\/\/www.aei.mpg.de\/14026\/AEI_Hannover\u0022\u003EAlbert Einstein Institute Hannover\u003C\/a\u003E, in Germany; Hillsdale College; Kenyon College; \u0026nbsp;Massachusetts Institute of Technology; Pennsylvania State University; \u003Ca href=\u0022http:\/\/www.ru.nl\/english\/\u0022\u003ERadboud University\u003C\/a\u003E, in the Netherlands; \u003Ca href=\u0022https:\/\/www.univ-paris-diderot.fr\/\u0022\u003EUniversit\u0026eacute; Paris Diderot\u003C\/a\u003E, in France; and the \u003Ca href=\u0022http:\/\/www.birmingham.ac.uk\/index.aspx\u0022\u003EUniversity of Birmingham\u003C\/a\u003E, in England.\u003C\/p\u003E\r\n\r\n\u003Cp\u003EJani received a \u003Ca href=\u0022https:\/\/www.youtube.com\/watch?v=_d2XtsLLRhQ\u0022\u003EPh.D. in spring 2017\u003C\/a\u003E. He worked with CRA Director \u003Ca href=\u0022https:\/\/www.physics.gatech.edu\/user\/deirdre-shoemaker\u0022\u003EDeirdre Shoemaker\u003C\/a\u003E, \u003Ca href=\u0022http:\/\/www.cos.gatech.edu\/hg\/item\/590681\u0022\u003ELSC Deputy Spokesperson Laura Cadonati\u003C\/a\u003E, and CRA colleagues \u003Ca href=\u0022http:\/\/www.cra.physics.gatech.edu\/people\/jbustillo3\u0022\u003EJuan Calderon Bustillo\u003C\/a\u003E, \u003Ca href=\u0022http:\/\/www.cra.physics.gatech.edu\/people\/jclark308\u0022\u003EJames Clark\u003C\/a\u003E, \u003Ca href=\u0022http:\/\/www.cra.physics.gatech.edu\/people\/clazzaro3\u0022\u003EClaudia Lazzaro\u003C\/a\u003E, and \u003Ca href=\u0022http:\/\/www.cra.physics.gatech.edu\/people\/plaguna3\u0022\u003EPablo Laguna\u003C\/a\u003E. All of them participated in the first detection of a gravitational wave, on Sept. 14, 2015.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Gravitational waves data suggest they are rare"}],"field_summary":[{"value":"\u003Cp\u003EBlack holes can be divided into three classes according to mass. On the low end are those with masses 10 times that of the sun. Examples are the two black holes whose merger generated the \u003Ca href=\u0022http:\/\/www.news.gatech.edu\/2016\/02\/11\/gravitational-waves-detected-100-years-after-einsteins-prediction\u0022\u003Efirst gravitational wave to be detected\u003C\/a\u003E.\u0026nbsp;On the high end are black holes that are a million times as massive as the sun. \u003Ca href=\u0022https:\/\/www.nasa.gov\/multimedia\/imagegallery\/image_feature_1846.html\u0022\u003EEvidence for them comes from NASA images\u003C\/a\u003E. For the Goldilocks black holes, with masses in between, no hard proof exists to date.\u0026nbsp;\u003C\/p\u003E\r\n","format":"limited_html"}],"field_summary_sentence":[{"value":"Analysis of gravitational waves data by hundreds of scientists so far reveals no collisions from mid-sized black holes."}],"uid":"30678","created_gmt":"2017-05-22 15:55:31","changed_gmt":"2017-05-23 16:29:40","author":"A. Maureen Rouhi","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2017-05-22T00:00:00-04:00","iso_date":"2017-05-22T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"591967":{"id":"591967","type":"image","title":"Georgia Tech\u0027s computer simulation of the merger of two small black holes, unleashing the first gravitational wave to be detected","body":null,"created":"1495457912","gmt_created":"2017-05-22 12:58:32","changed":"1495467888","gmt_changed":"2017-05-22 15:44:48","alt":"","file":{"fid":"225614","name":"Grav.waves_.IMBH_Poster_KPJ.png","image_path":"\/sites\/default\/files\/images\/Grav.waves_.IMBH_Poster_KPJ.png","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/images\/Grav.waves_.IMBH_Poster_KPJ.png","mime":"image\/png","size":3667229,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/Grav.waves_.IMBH_Poster_KPJ.png?itok=igODO42_"}}},"media_ids":["591967"],"groups":[{"id":"1278","name":"College of Sciences"},{"id":"126011","name":"School of Physics"}],"categories":[{"id":"135","name":"Research"}],"keywords":[{"id":"99091","name":"Gravitational waves"},{"id":"120161","name":"LIGO"},{"id":"166937","name":"School of Physics"},{"id":"4896","name":"College of Sciences"},{"id":"10881","name":"black holes"},{"id":"173122","name":"KAran Jani"},{"id":"174488","name":"Deirdre Shoemaker."},{"id":"120191","name":"Laura Cadonati"}],"core_research_areas":[{"id":"39431","name":"Data Engineering and Science"}],"news_room_topics":[{"id":"71881","name":"Science and Technology"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EA. Maureen Rouhi, Ph.D.\u003Cbr \/\u003E\r\nDirector of Communications\u003Cbr \/\u003E\r\nCollege of Sciences\u003C\/p\u003E\r\n","format":"limited_html"}],"email":["maureen.rouhi@cos.gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}