Black HoleSome 3.9 billion years ag

Black Hole
Some 3.9 billion years ago in the heart of a distant galaxy, the intense tidal pull of a monster black hole shredded a star that passed too close. When X-rays produced in this event first reached Earth on March 28, 2011, they were detected by NASA's Swift satellite, which notified astronomers around the world. Within days, scientists concluded that the outburst, now known as Swift J1644+57, represented both the tidal disruption of a star and the sudden flare-up of a previously inactive black hole.


NASA Goddard astronomer Erin Kara discusses the discovery of X-ray echoes from Swift J1644+57, a black hole that shattered a passing star. X-rays produced by flares near this million-solar-mass black hole bounced off the nascent accretion disk and revealed its structure.
Credits: NASA's Goddard Space Flight Center
Download high-resolution video at NASA’s Scientific Visualization Studio
Now astronomers using archival observations from Swift, the European Space Agency's (ESA) XMM-Newton observatory and the Japan-led Suzaku satellite have identified the reflections of X-ray flares erupting during the event. Led by Erin Kara, a postdoctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park (UMCP), the team has used these light echoes, or reverberations, to map the flow of gas near a newly awakened black hole for the first time.

"While we don't yet understand what causes X-ray flares near the black hole, we know that when one occurs we can detect its echo a couple of minutes later, once the light has reached and illuminated parts of the flow," Kara explained. "This technique, called X-ray reverberation mapping, has been previously used to explore stable disks around black holes, but this is the first time we've applied it to a newly formed disk produced by a tidal disruption."

Thick accretion disk around supermassive black hole, stellar debris falling toward black hole, X-ray light burst near center
In this artist's rendering, a thick accretion disk has formed around a supermassive black hole following the tidal disruption of a star that wandered too close. Stellar debris has fallen toward the black hole and collected into a thick chaotic disk of hot gas. Flashes of X-ray light near the center of the disk result in light echoes that allow astronomers to map the structure of the funnel-like flow, revealing for the first time strong gravity effects around a normally quiescent black hole.
Credits: NASA/Swift/Aurore Simonnet, Sonoma State University
Stellar debris falling toward a black hole collects into a rotating structure called an accretion disk. There the gas is compressed and heated to millions of degrees before it eventually spills over the black hole's event horizon, the point beyond which nothing can escape and astronomers cannot observe. The Swift J1644+57 accretion disk was thicker, more turbulent and more chaotic than stable disks, which have had time to settle down into an orderly routine. The researchers present the findings in a paper published online in the journal Nature on Wed., June 22.

One surprise from the study is that high-energy X-rays arise from the inner part of the disk. Astronomers had thought most of this emission originated from a narrow jet of particles accelerated to near the speed of light. In blazars, the most luminous galaxy class powered by supermassive black holes, jets produce most of the highest-energy emission.

"We do see a jet from Swift J1644, but the X-rays are coming from a compact region near the black hole at the base of a steep funnel of inflowing gas we're looking down into," said co-author Lixin Dai, a postdoctoral researcher at UMCP. "The gas producing the echoes is itself flowing outward along the surface of the funnel at speeds up to half the speed of light."

X-rays originating near the black hole excite iron ions in the whirling gas, causing them to fluoresce with a distinctive high-energy glow called iron K-line emission. As an X-ray flare brightens and fades, the gas follows in turn after a brief delay depending on its distance from the source.

"Direct light from the flare has different properties than its echo, and we can detect reverberations by monitoring how the brightness changes across different X-ray energies," said co-author Jon Miller, a professor of astronomy at the University of Michigan in Ann Arbor.

Swift J1644+57 is one of only three tidal disruptions that have produced high-energy X-rays, and to date it remains the only event caught at the peak of this emission. These star shredding episodes briefly activate black holes astronomers wouldn't otherwise know about. For every black hole now actively accreting gas and producing light, astronomers think nine others are dormant and dark. These quiescent black holes were active when the universe was younger, and they played an important role in how galaxies evolved. Tidal disruptions therefore of

ผลลัพธ์ (ไทย) 1:

หลุมดำ3.9 พันล้านปีก่อนในใจกลางของดาราจักรที่อยู่ไกล การดึงยาวรุนแรงของหลุมดำมอนสเตอร์ฝอยดาวที่ผ่านใกล้เกินไป เมื่อไอออนที่ผลิตในเหตุการณ์นี้ถึงโลกครั้งแรกเมื่อ 28 มีนาคม 2011 พวกเขาพบทางของนา Swift ดาวเทียม ที่แจ้งนักดาราศาสตร์ทั่วโลก ภายใน นักวิทยาศาสตร์ได้ข้อสรุปว่า ระเบิด ตอนนี้ เรียกว่า Swift J1644 + 57 แสดงทั้งหยุดชะงักยาวของดาวและแม้ว่าฉับพลันของหลุมดำไม่ได้ใช้งานก่อนหน้านี้นักดาราศาสตร์ของนาซ่าก็อดเดิร์ด Erin Kara กล่าวถึงการค้นพบเอกซเรย์สะท้อนจาก Swift J1644 + 57 หลุมดำที่ผ่านดาว รังสีเอกซ์โดยพลุใกล้หลุมดำนี้ล้านมวลพลังงานแสงอาทิตย์ที่สะท้อนออกดิสก์ nascent accretion ที่จดจำ และเปิดเผยโครงสร้างเครดิต: ของนาซ่าก็อดเดิร์ดศูนย์การบินอวกาศดาวน์โหลดวิดีโอความละเอียดสูงที่สตูดิโอการแสดงทางวิทยาศาสตร์ของนาซ่าตอนนี้นักดาราศาสตร์ใช้จดหมายเหตุสังเกตจาก Swift ที่องค์การอวกาศยุโรป (ESA) นิวตัน XMM หอดูดาวและดาวเทียมประเทศญี่ปุ่นนำปรับเปลี่ยนง่ายดายได้ระบุสะท้อนของพลุเอ็กซเรย์ในระหว่างเหตุการณ์ที่ปะทุขึ้น นำ โดย Erin Kara นักวิจัยหลังที่ศูนย์การบินอวกาศก็อดเดิร์ดของนาซ่าในสาธารณะกรีนเบลท์ แมรี่แลนด์ และมหาวิทยาลัยแมริแลนด์ วิทยาลัยสวน (UMCP), ทีมงานได้ใช้หรือเหล่านี้สะท้อนแสง เสียง การไหลของก๊าซใกล้หลุมดำ awakened ใหม่ครั้งแรก"While we don't yet understand what causes X-ray flares near the black hole, we know that when one occurs we can detect its echo a couple of minutes later, once the light has reached and illuminated parts of the flow," Kara explained. "This technique, called X-ray reverberation mapping, has been previously used to explore stable disks around black holes, but this is the first time we've applied it to a newly formed disk produced by a tidal disruption."Thick accretion disk around supermassive black hole, stellar debris falling toward black hole, X-ray light burst near centerIn this artist's rendering, a thick accretion disk has formed around a supermassive black hole following the tidal disruption of a star that wandered too close. Stellar debris has fallen toward the black hole and collected into a thick chaotic disk of hot gas. Flashes of X-ray light near the center of the disk result in light echoes that allow astronomers to map the structure of the funnel-like flow, revealing for the first time strong gravity effects around a normally quiescent black hole.Credits: NASA/Swift/Aurore Simonnet, Sonoma State UniversityStellar debris falling toward a black hole collects into a rotating structure called an accretion disk. There the gas is compressed and heated to millions of degrees before it eventually spills over the black hole's event horizon, the point beyond which nothing can escape and astronomers cannot observe. The Swift J1644+57 accretion disk was thicker, more turbulent and more chaotic than stable disks, which have had time to settle down into an orderly routine. The researchers present the findings in a paper published online in the journal Nature on Wed., June 22. One surprise from the study is that high-energy X-rays arise from the inner part of the disk. Astronomers had thought most of this emission originated from a narrow jet of particles accelerated to near the speed of light. In blazars, the most luminous galaxy class powered by supermassive black holes, jets produce most of the highest-energy emission."We do see a jet from Swift J1644, but the X-rays are coming from a compact region near the black hole at the base of a steep funnel of inflowing gas we're looking down into," said co-author Lixin Dai, a postdoctoral researcher at UMCP. "The gas producing the echoes is itself flowing outward along the surface of the funnel at speeds up to half the speed of light."X-rays originating near the black hole excite iron ions in the whirling gas, causing them to fluoresce with a distinctive high-energy glow called iron K-line emission. As an X-ray flare brightens and fades, the gas follows in turn after a brief delay depending on its distance from the source. "Direct light from the flare has different properties than its echo, and we can detect reverberations by monitoring how the brightness changes across different X-ray energies," said co-author Jon Miller, a professor of astronomy at the University of Michigan in Ann Arbor.Swift J1644+57 is one of only three tidal disruptions that have produced high-energy X-rays, and to date it remains the only event caught at the peak of this emission. These star shredding episodes briefly activate black holes astronomers wouldn't otherwise know about. For every black hole now actively accreting gas and producing light, astronomers think nine others are dormant and dark. These quiescent black holes were active when the universe was younger, and they played an important role in how galaxies evolved. Tidal disruptions therefore of