{"id":14300,"date":"2021-03-10T00:00:00","date_gmt":"2021-03-10T00:00:00","guid":{"rendered":"https:\/\/www.nextias.com\/current_affairs\/uncategorized\/10-03-2021\/p17218-quasar\/"},"modified":"2021-03-10T00:00:00","modified_gmt":"2021-03-10T00:00:00","slug":"p17218-quasar","status":"publish","type":"post","link":"https:\/\/www.nextias.com\/ca\/current-affairs\/10-03-2021\/p17218-quasar","title":{"rendered":"P172+18 Quasar"},"content":{"rendered":"<p><strong>In News<\/strong><\/p>\n<ul>\n<li>An international team of <strong>astronomers<\/strong> have discovered the most distant <strong>\u2018radio-loud<\/strong>\u2019 quasar with the help of the <strong>European Southern Observatory\u2019s Very Large Telescope (ESO\u2019s VLT).<\/strong><\/li>\n<\/ul>\n<p><strong>About the Discovery <\/strong><\/p>\n<ul>\n<li>It is named <strong>P172+18, the quasar emitted wavelengths which had a redshift of 6.8.<\/strong>\n<ul>\n<li>Gravitational redshift occurs as <strong>particles of light (photons) climb out of a gravitational well <\/strong>like a black hole and the light&#8217;s wavelength gets drawn out. This shifts the wavelength to the red part of the light spectrum &#8211; hence &#8220;redshift&#8221;.<\/li>\n<li>It took <strong>13 billion years<\/strong> for the quasar\u2019s light to reach earth<strong>. <\/strong><\/li>\n<li>The higher the <strong>redshift of the radio wavelength,<\/strong> the <strong>farther away <\/strong>is the source.<\/li>\n<\/ul>\n<\/li>\n<li>The <strong>glowing disc around a blackhole is 300 million<\/strong> times more massive than our Sun.<\/li>\n<li>It is also one of the fastest accreting quasars, which means it is accumulating objects from the galaxy at an enormous speed.<\/li>\n<li>Only three other <strong>\u2018radio-loud\u2019 sources<\/strong> with redshift greater than six have been discovered so far and the most distant one had a <strong>redshift of 6.18<\/strong>.<\/li>\n<li>The scientists think that the powerful radio jets shooting out of the quasar fuelled the <strong>appetite of the black hole.<\/strong>\n<ul>\n<li>The jets are thought to be <strong>capable of disturbing the gas<\/strong> around the<strong> black hole, increasing the rate at which gas falls in.<\/strong><\/li>\n<\/ul>\n<\/li>\n<li><strong>Inference: <\/strong>The blackhole at its centre is consuming from its galaxy at a stunning rate.<\/li>\n<\/ul>\n<p><strong>Significance <\/strong><\/p>\n<ul>\n<li>A detailed study of these \u2018radio-loud\u2019 super bright objects <strong>can help the astronomers to understand how the supermassive black holes <\/strong>in their <strong>core grew to be as big so rapidly since the Big Bang.<\/strong><\/li>\n<li>The team believes that <strong>more such quasars <\/strong>that tell stories about the <strong>ancient universe will be found, perhaps even farther away from earth.<\/strong><\/li>\n<\/ul>\n<p><strong>What are Quasars?<\/strong><\/p>\n<p><strong><img decoding=\"async\" src=\"https:\/\/cfstatic.nextias.com\/cdn-cgi\/image\/format=auto\/file_library\/mix_content\/713747514792585900_image.png\" style=\"height:207px; margin-left:150px; margin-right:150px; width:346px\" \/><\/strong><\/p>\n<ul>\n<li><strong>Quasi Stellar radio sources, abbreviated QUASARS, <\/strong>are the most dynamic and far-off objects in a collective known as <strong>active galactic nuclei (AGN)<\/strong>.<\/li>\n<li><strong>Its spectrum consisted of wide emission lines, unlike stars, thus the name \u201cquasi-stellar.\u201d<\/strong><\/li>\n<li>These radiant sources were formed <strong>approximately twelve billion years ago<\/strong>.<\/li>\n<li><strong>Quasar formations<\/strong> take place by the<strong> collision of galaxies, i<\/strong>.e., the<strong> central black holes <\/strong>merge to form a <strong>supermassive black hole.<\/strong><\/li>\n<li><strong>Quasars are very luminous objects <\/strong>in<strong> faraway galaxies<\/strong> that <strong>emit jets at radio frequencies. <\/strong>They are only found in <strong>galaxies <\/strong>that have s<strong>upermassive black holes<\/strong> which power these bright discs.<\/li>\n<li>\u00a0However, <strong>90 percent of them<\/strong> do not <strong>emit strong radio waves<\/strong>, making this n<strong>ewly-discovered one special.<\/strong><\/li>\n<li>Most active <strong>galaxies have a supermassive black hol<\/strong>e at the centre which sucks in s<strong>urrounding objects.<\/strong><\/li>\n<\/ul>\n<ul>\n<li>Although quasars were<strong> originally discovered<\/strong> due to their<strong> radio emissions<\/strong>, only about <strong>10% of quasars have substantial radio emissions. <\/strong>\n<ul>\n<li><strong>These quasars<\/strong> are <strong>now called radio-loud quasars<\/strong>.<\/li>\n<li>Quasars <strong>without strong radio emissions<\/strong> are called <strong>radio-quiet quasars<\/strong><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<table border=\"1\" cellspacing=\"0\" style=\"width:624px\">\n<tbody>\n<tr>\n<td style=\"background-color:#fff2cc; width:468.0pt\">\n<p><strong>Blackhole <\/strong><\/p>\n<ul>\n<li>It is a <strong>region in space<\/strong> where the <strong>pulling force of gravity<\/strong> is so strong that neither <strong>matter nor light can escape.<\/strong> This phenomenon occurs when a <strong>star is dying.<\/strong><\/li>\n<li>For anything approaching a black hole, the point of no return is called the <strong>\u201cevent horizon\u201d <\/strong>and anything that c<strong>omes within the event horizon will be consumed forever.<\/strong><\/li>\n<li>Since <strong>no light can escape from it,<\/strong> a <strong>black hole is invisible<\/strong>.<\/li>\n<li>However, <strong>advanced space telescopes<\/strong> can <strong>identify black holes <\/strong>by observing the <strong>behaviour of material<\/strong> and <strong>stars that are very close to black holes<\/strong>.<\/li>\n<li>This hot <strong>disk of material encircling<\/strong> a <strong>black hole shines bright and against this disk<\/strong>, a<strong> black hole appears<\/strong> to <strong>cast a shadow.<\/strong><\/li>\n<li>This is how the <strong>photograph of the black hole was achieved.<\/strong><\/li>\n<li>In 2019, NASA released the f<strong>irst-ever photograph of a black hole<\/strong> and its shadow, which was captured by an i<strong>nternational network of radio telescopes called the Event Horizon Telescope (EHT).<\/strong>\n<ul>\n<li>The image shows the shadow of a supermassive black hole in the centre of Messier 87 (M87), an elliptical galaxy some 55 million light-years from Earth.<\/li>\n<li>This black hole is 6.5 billion times the mass of the Sun.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><strong><img decoding=\"async\" src=\"https:\/\/cfstatic.nextias.com\/cdn-cgi\/image\/format=auto\/file_library\/mix_content\/538201798559548350_image.png\" style=\"height:471px; margin-left:50px; margin-right:50px; width:416px\" \/><\/strong><\/p>\n<p><strong>About the ESO\u2019s VLT:<\/strong><\/p>\n<ul>\n<li>The Very Large Telescope array (VLT) is the flagship facility for <strong>European ground-based <\/strong>astronomy at the<strong> beginning of the third Millennium.<\/strong><\/li>\n<li><strong>Very Large Telescope (VLT), an observatory located on the mountain Cerro Paranal (2,635 metres [8,645 feet]) in Chile <\/strong><\/li>\n<li>It is the <strong>world&#8217;s most advanced optical instrument<\/strong>, <strong>consisting of four Unit Telescopes<\/strong> with <strong>main mirrors of 8.2m diameter and four movable 1.8m diameter<\/strong> Auxiliary Telescopes.\n<ul>\n<li>The telescopes can work together, to form a <strong>giant \u2018interferometer\u2019<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<li>The ESO Very Large Telescope Interferometer, allowing astronomers to see details up to <strong>25 times finer than with the individual telescopes.<\/strong><\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><a href=\"https:\/\/www.downtoearth.org.in\/news\/science-technology\/most-distant-source-of-radio-emission-discovered-holds-clues-about-ancient-universe-75833\" target=\"_blank\" rel=\"noopener\">Source :DTH<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In News An international team of astronomers have discovered the most distant \u2018radio-loud\u2019 quasar with the help of the European Southern Observatory\u2019s Very Large Telescope (ESO\u2019s VLT). About the Discovery It is named P172+18, the quasar emitted wavelengths which had a redshift of 6.8. Gravitational redshift occurs as particles of light (photons) climb out of [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":14301,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21],"tags":[],"class_list":["post-14300","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-current-affairs"],"acf":[],"jetpack_featured_media_url":"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2023\/07\/7882145current-affairs (1).jpg","_links":{"self":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/14300","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/comments?post=14300"}],"version-history":[{"count":0,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/14300\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media\/14301"}],"wp:attachment":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media?parent=14300"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/categories?post=14300"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/tags?post=14300"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}