Case Study: Western Digital Plays Pivotal Role in First-Ever Image of A

Total Page:16

File Type:pdf, Size:1020Kb

Case Study: Western Digital Plays Pivotal Role in First-Ever Image of A Credit: EHT Collaboration. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) CASE STUDY Western Digital Plays Pivotal Role in First-Ever Image of a Black Hole International black hole imaging team turns to Messier 87* Western Digital’s Ultrastar® HDDs with HelioSeal® By the Numbers technology to capture massive amounts of data in extreme conditions The galaxy known as M87 is 53 million light-years away.1 With several trillion stars, a family of approximately 15,000 globular star clusters, and a supermassive black hole, it is one of the largest galaxies in our universe.2 53 million light-years Separate Earth and the M87* Supermassive black hole. That’s far. 12.5 million times farther than the closest star to our solar system, Proxima Centauri.² The project involved… 8 telescopes around the world collected the data over several days in April 2017. 200 researchers4 Figure 1: Messier 87 60 When an international team of astronomers and computer scientists targeted the scientific institutions heart of M87 to capture the first-ever image of a black hole, it made headlines around the world. Less heralded was the astronomical amount of data needed to create that image—approximately 4.5 petabytes.3 To put this in perspective, the size of a typical low-resolution smartphone photo is 3.5 megabytes. The data needed to create an image 20 of the black hole was over 1,000,000,000X larger than a typical smartphone photo and is countries5 as much data as taking 4,000 typical smartphone photos per day for close to 900 years.4 The Event Horizon Telescope project gathered that much data in the span of ten days in April 2017.5 350 ~4.5 960 Capturing M87’s black hole was no small feat—one researcher compared it to taking terabytes collected petabytes of data hard drives a photo of an orange on the surface of the moon from Earth.1 To create an instrument 6 7 8 each day collected total stored that data powerful enough to collect images even of an object of that size 53 million light-years away, researchers connected eight highly sophisticated telescopes around the world That much data is equivalent to taking 4,000 photos a day for almost 200 years on your cellphone.9 to create one virtual, Earth-sized telescope using a method called Very Long Baseline Interferometry (VLBI). (continued on next page) Trucks and planes delivered the hard drives to data centers in Cambridge, MA and Bonn, Germany. Western Digital Plays Pivotal Role in First-Ever Image of a Black Hole Transferring all of that data over 10 the internet would’ve taken ~25 years 4 computer-imaging algorithms 11 were used by 4 independent groups of experts to help eliminate bias in reviewing the findings. The result? 1 history-making photo†. M87* Image Credit: EHT Collaboration. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) Messier 87* By the Numbers 53 million light-years Separate Earth and the M87* Supermassive black hole. That’s far. 12.5 million times farther than the closest star to our solar system, Proxima Centauri.² The project involved… 8 telescopes around the world collected the data over several days in April 2017. 200 researchers4 60 scientific institutions 20 countries5 350 ~4.5 960 terabytes collected petabytes of data hard drives 6 7 8 each day collected total stored that data CASE STUDYThat much data is equivalent to taking 4,000 photos a day for almost 200 years on your cellphone.9 Each individual telescope was part of a virtual telescope called the Event Horizon Trucks and planes delivered Telescope. The individual telescopes were synchronized together with GPS and highly- the hard drives to data accurate atomic clocks to ensure consistency in the images they captured. Each data centers in Cambridge, MA and Bonn, Germany. point the telescopes captured was digitized, time-stamped and saved to hard disk drives (HDDs).6 The hard drives used for this astronomy data needed to be both powerful enough to Transferring all of that data over 10 collect megabytes of data per second flowing from telescopes around the world, and the internet would’ve taken ~25 years tough enough to withstand the punishing environments where many of these instruments are based. 4 computer-imaging algorithms 11 Western Digital’s Ultrastar HDDs with HelioSeal technology helped provide the solution were used by 4 independent groups of experts to help eliminate bias in reviewing the findings. for collecting massive amounts of data in extreme conditions. HelioSeal technology hermetically seals the hard drive and replaces air with helium, which is 1/7th the density of air. Western Digital was the first company to ship helium-filled HDDs, which enable higher densities, higher performance, less energy and greater reliability compared to air-filled drives. Helium-filled HDDs enabled data capture and storage in the extreme climates of some of The result? these telescopes, from freezing temperatures in Antarctica to high altitudes in Mexico, 1 history-making photo†. where air-filled drives would not function properly. Once the drives collected the astronomy data, they were transported (not via the internet, but by plane and by car6) to research centers in the U.S. and Germany for processing—the end result of which, of course, is the iconic image that captivated the world in 2019. The M87 black hole image is the perfect example of the power that data represents. With the ability to collect and analyze data at scale, we can see what was previously unseen and reveal insights that previously lay in shadow. In a very real way, data is opening up a M87* Image Credit: EHT Collaboration. Licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) Credit: EHT Collaboration. Licensed under CC BY 4.0 whole universe of discovery. (https://creativecommons.org/licenses/by/4.0/) This content is produced by WIRED Brand Lab in collaboration with Western Digital. Article Sources: Infographic Sources: 1 How Scientists Captured the First Image of a Black Hole 1 How Scientists Captured the First Image of a Black Hole (https://www.jpl.nasa.gov/edu/news/2019/4/19/how-scientists-captured-the-first-image-of-a-black-hole/) (https://www.jpl.nasa.gov/edu/news/2019/4/19/how-scientists-captured-the-first-image-of-a-black-hole/) 2 Messier 87 (https://www.nasa.gov/feature/goddard/2017/messier-87) 2 How Long Would It Take To Travel To The Nearest Star? 3 AskScience AMA Series: We are scientists here to discuss our breakthrough results from the Event Horizon (https://www.universetoday.com/15403/how-long-would-it-take-to-travel-to-the-nearest-star/) Telescope. AUA! (https://www.reddit.com/r/askscience/comments/bbknik/askscience_ama_series_we_ 3 How They Took the First Picture of a Black Hole are_scientists_here_to/ekk3cgp/) (https://www.nytimes.com/interactive/2019/04/10/science/event-horizon-black-hole-images.html) 4 Average file sizes vary but cellphone photos are generally ~3-3.5 MB. Examples of the number of photos that 4 This is the first photo of a black hole can be stored are provided for illustrative purposes only. Results will vary based on resolution, content, file (https://www.cnn.com/2019/04/10/world/black-hole-photo-scn/index.html) compression, file format, file size, host device, pre-loaded files, settings, software and other factors. 5 Astronomers Capture First-Ever Image of a Supermassive Black Hole (https://www.cnet.com/news/iphone-6s-camera-filesizes-4k-live-photos-hdr/) (https://www.smithsonianmag.com/science-nature/astronomers-capture-first-images-supermassive-black- 5 How They Took the First Picture of a Black Hole hole-180971927/#vDRqXF0GA5hxH9wp.99) (https://www.nytimes.com/interactive/2019/04/10/science/event-horizon-black-hole-images.html) 6 Black hole images captured in world first 6 The Hidden Shipping and Handling Behind That Black-Hole Picture (https://www.ucl.ac.uk/news/2019/apr/black-hole-images-captured-world-first-0) (https://www.theatlantic.com/science/archive/2019/04/black-hole-hard-disks-picture/587119/) 7 Taking that picture of a black hole required massive amounts of data (https://www.techspot.com/news/79637-taking-picture-black-hole-required-massive-amounts-data.html) 8 Why the Event Horizon Telescope took so long to image a black hole (http://www.astronomy.com/news/2019/04/the-road-to-imaging-a-black-hole) 9 Average file sizes vary but typical low-resolution cellphone photos are generally ~3-3.5 MB. Examples of the number of photos that can be stored are provided for illustrative purposes only. Results will vary based on resolution, content, file compression, file format, file size, host device, pre-loaded files, settings, software and other factors. (https://www.cnet.com/news/iphone-6s-camera-filesizes-4k-live-photos-hdr/) 10Behind the Scenes of the First Black Hole Photo (https://www.popularmechanics.com/space/telescopes/a27131631/behind-the-scenes-of-the-first-black- hole-photo/) 11Algorithms gave us the black hole picture. She’s the 29-year-old scientist who helped create them (https://www.washingtonpost.com/science/2019/04/10/algorithms-gave-us-black-hole-pic-this-scientist- helped-create-them/?utm_term=.ca75c249a84d) 5601 Great Oaks Parkway ©2020 Western Digital Corporation or its affiliates. All rights reserved. Western Digital, the Western Digital logo, HelioSeal, and Ultrastar are registered trademarks or San Jose, CA 95119, USA trademarks of Western Digital Corporation or its affiliates in the US and/or other countries. All other marks are the property of their respective owners. US (Toll-Free): 1.888.426.5214 International: 408.717.6000 www.westerndigital.com Western Digital Plays Pivotal Role in First-Ever Image of a Black Hole April 2020.
Recommended publications
  • Messier Objects
    Messier Objects From the Stocker Astroscience Center at Florida International University Miami Florida The Messier Project Main contributors: • Daniel Puentes • Steven Revesz • Bobby Martinez Charles Messier • Gabriel Salazar • Riya Gandhi • Dr. James Webb – Director, Stocker Astroscience center • All images reduced and combined using MIRA image processing software. (Mirametrics) What are Messier Objects? • Messier objects are a list of astronomical sources compiled by Charles Messier, an 18th and early 19th century astronomer. He created a list of distracting objects to avoid while comet hunting. This list now contains over 110 objects, many of which are the most famous astronomical bodies known. The list contains planetary nebula, star clusters, and other galaxies. - Bobby Martinez The Telescope The telescope used to take these images is an Astronomical Consultants and Equipment (ACE) 24- inch (0.61-meter) Ritchey-Chretien reflecting telescope. It has a focal ratio of F6.2 and is supported on a structure independent of the building that houses it. It is equipped with a Finger Lakes 1kx1k CCD camera cooled to -30o C at the Cassegrain focus. It is equipped with dual filter wheels, the first containing UBVRI scientific filters and the second RGBL color filters. Messier 1 Found 6,500 light years away in the constellation of Taurus, the Crab Nebula (known as M1) is a supernova remnant. The original supernova that formed the crab nebula was observed by Chinese, Japanese and Arab astronomers in 1054 AD as an incredibly bright “Guest star” which was visible for over twenty-two months. The supernova that produced the Crab Nebula is thought to have been an evolved star roughly ten times more massive than the Sun.
    [Show full text]
  • The Messier Catalog
    The Messier Catalog Messier 1 Messier 2 Messier 3 Messier 4 Messier 5 Crab Nebula globular cluster globular cluster globular cluster globular cluster Messier 6 Messier 7 Messier 8 Messier 9 Messier 10 open cluster open cluster Lagoon Nebula globular cluster globular cluster Butterfly Cluster Ptolemy's Cluster Messier 11 Messier 12 Messier 13 Messier 14 Messier 15 Wild Duck Cluster globular cluster Hercules glob luster globular cluster globular cluster Messier 16 Messier 17 Messier 18 Messier 19 Messier 20 Eagle Nebula The Omega, Swan, open cluster globular cluster Trifid Nebula or Horseshoe Nebula Messier 21 Messier 22 Messier 23 Messier 24 Messier 25 open cluster globular cluster open cluster Milky Way Patch open cluster Messier 26 Messier 27 Messier 28 Messier 29 Messier 30 open cluster Dumbbell Nebula globular cluster open cluster globular cluster Messier 31 Messier 32 Messier 33 Messier 34 Messier 35 Andromeda dwarf Andromeda Galaxy Triangulum Galaxy open cluster open cluster elliptical galaxy Messier 36 Messier 37 Messier 38 Messier 39 Messier 40 open cluster open cluster open cluster open cluster double star Winecke 4 Messier 41 Messier 42/43 Messier 44 Messier 45 Messier 46 open cluster Orion Nebula Praesepe Pleiades open cluster Beehive Cluster Suburu Messier 47 Messier 48 Messier 49 Messier 50 Messier 51 open cluster open cluster elliptical galaxy open cluster Whirlpool Galaxy Messier 52 Messier 53 Messier 54 Messier 55 Messier 56 open cluster globular cluster globular cluster globular cluster globular cluster Messier 57 Messier
    [Show full text]
  • Arxiv:1301.7294V1 [Physics.Hist-Ph] 30 Jan 2013 2 1 Eds
    Origins of the Expanding Universe: 1912-1932 ASP Conference Series, Vol. 471 Michael J. Way and Deidre Hunter, eds. c 2013 Astronomical Society of the Pacific Dismantling Hubble’s Legacy? Michael J. Waya,b aNASA/Goddard Institute for Space Studies, New York, NY, 10029 USA bDepartment of Astronomy, Uppsala University, Uppsala, Sweden Abstract. Edwin Hubble is famous for a number of discoveries that are well known to amateur and professional astronomers, students and the general public. The origins of these discoveries are examined and it is demonstrated that, in each case, a great deal of supporting evidence was already in place. In some cases the discoveries had either already been made, or competing versions were not adopted for complex scientific and sociological reasons. 1. Introduction Edwin Hubble is considered one of the titans of early 20th century observational cos- mology. He is credited in most textbooks1 and the popular literature for a series of important discoveries made between 1920 and 1930: • The confirmation of the Island Universe hypothesis • The classification of extragalactic nebulae • The discovery of a linear relationship between distance and velocity for extra- galactic nebulae, providing the first evidence for the expanding universe • The brightness profile of galaxies The discoveries above are well-known to the astronomy community and most as- tronomers would associate them solely with Edwin Hubble; yet this is a gross over- simplification. Astronomers and historians are beginning to revise that standard story and bring a more nuanced version to the public’s attention. This paper is adding to this arXiv:1301.7294v1 [physics.hist-ph] 30 Jan 2013 burgeoning reappraisal.2 As a (small) counter-narrative, William Hoyt (1980, p.
    [Show full text]
  • Astronomy and Astrophysics Books in Print, and to Choose Among Them Is a Difficult Task
    APPENDIX ONE Degeneracy Degeneracy is a very complex topic but a very important one, especially when discussing the end stages of a star’s life. It is, however, a topic that sends quivers of apprehension down the back of most people. It has to do with quantum mechanics, and that in itself is usually enough for most people to move on, and not learn about it. That said, it is actually quite easy to understand, providing that the information given is basic and not peppered throughout with mathematics. This is the approach I shall take. In most stars, the gas of which they are made up will behave like an ideal gas, that is, one that has a simple relationship among its temperature, pressure, and density. To be specific, the pressure exerted by a gas is directly proportional to its temperature and density. We are all familiar with this. If a gas is compressed, it heats up; likewise, if it expands, it cools down. This also happens inside a star. As the temperature rises, the core regions expand and cool, and so it can be thought of as a safety valve. However, in order for certain reactions to take place inside a star, the core is compressed to very high limits, which allows very high temperatures to be achieved. These high temperatures are necessary in order for, say, helium nuclear reactions to take place. At such high temperatures, the atoms are ionized so that it becomes a soup of atomic nuclei and electrons. Inside stars, especially those whose density is approaching very high values, say, a white dwarf star or the core of a red giant, the electrons that make up the central regions of the star will resist any further compression and themselves set up a powerful pressure.1 This is termed degeneracy, so that in a low-mass red 191 192 Astrophysics is Easy giant star, for instance, the electrons are degenerate, and the core is supported by an electron-degenerate pressure.
    [Show full text]
  • A Portrait of a Black Hole
    Overview_Black Holes A picture of a dark monster. The image is the first direct visual evidence of a black hole. This particularly massive specimen is at the center of the supergiant galaxy Messier 87 and was acquired by the Event Horizon Telescope (EHT), an array of eight ground-based radio telescopes distributed around the globe. A portrait of a black hole Black holes swallow all light, making them invisible. That’s what you’d think anyway, but astronomers thankfully know that this isn’t quite the case. They are, in fact, surrounded by a glowing disc of gas, which makes them visible against this bright background, like a black cat on a white sofa. And that’s how the Event Horizon Telescope has now succeeded in taking the first picture of a black hole. Researchers from the Max Planck Institute for Radio Astronomy in Bonn and the Institute for Radio Astronomy in the Millimeter Range (IRAM) in Grenoble, France, were among those making the observations. Photo: EHT Collaboration TEXT HELMUT HORNUNG n spring 2017, scientists linked up objects at extremely small angles of less tion of the Max Planck Institute for Ra- eight telescopes spread out over than 20 microarcseconds. With that dio Astronomy. In the 2017 observing one face of the globe for the first resolution, our eyes would see individ- session alone, the telescopes recorded time, forming a virtual telescope ual molecules on our own hands. approximately four petabytes of data. with an effective aperture close to This is such a huge volume that it was the Idiameter of the entire planet.
    [Show full text]
  • First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
    The Astrophysical Journal Letters, 875:L5 (31pp), 2019 April 10 https://doi.org/10.3847/2041-8213/ab0f43 © 2019. The American Astronomical Society. First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring The Event Horizon Telescope Collaboration (See the end matter for the full list of authors.) Received 2019 March 4; revised 2019 March 12; accepted 2019 March 12; published 2019 April 10 Abstract The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data. To this end, we construct a large library of models based on general relativistic magnetohydrodynamic (GRMHD) simulations and synthetic images produced by general relativistic ray tracing. We compare the observed visibilities with this library and confirm that the asymmetric ring is consistent with earlier predictions of strong gravitational lensing of synchrotron emission from a hot plasma orbiting near the black hole event horizon. The ring radius and ring asymmetry depend on black hole mass and spin, respectively, and both are therefore expected to be stable when observed in future EHT campaigns. Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. If the black hole spin and M87’s large scale jet are aligned, then the black hole spin vector is pointed away from Earth. Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets.
    [Show full text]
  • Sagittarius A*​ Selfies…?
    Sagittarius A* Selfies…? ​ Daven M.F. Cocroft Ever wonder what a black hole looks like? Kind of VLBI is a technique that uses multiple telescopes, a weird question considering that the gravity of thousands of miles apart, in order to make black holes is so strong that once light gets too observations (Figure 1). Signals from outer space close, it gets trapped and can never reach our eyes reach each telescope individually and are recorded. to be processed into an actual image of a black hole. Later, the data from all of the involved telescopes However, an international collaboration, known as are brought together and combined to form a larger, the Event Horizon Telescope (EHT), may have more wholistic dataset. There is usually some sort found a way to give us some type of visualization of of atomic clock involved in the process to properly a black hole! Actually, they will be trying to make account for time differences and ensure that data are observations of the event horizon of a black hole, combined as seamlessly as possible. Though, one which is the boundary past which light can no big problem that comes with using this technique is longer escape the gravitational pull of a black hole that observations can only be made when the chosen (Figure 2). Using an “array” of telescopes across telescopes can operate at the same time. Thus, a lot the globe in a technique called Very Long Baseline of planning has to go into any observations, and the Interferometry (VLBI), the EHT is essentially using EHT can only observe about once a year.
    [Show full text]
  • Charles Messier (1730-1817) Was an Observational Astronomer Working
    Charles Messier (1730-1817) was an observational Catalogue (NGC) which was being compiled at the same astronomer working from Paris in the eighteenth century. time as Messier's observations but using much larger tele­ He discovered between 15 and 21 comets and observed scopes, probably explains its modern popularity. It is a many more. During his observations he encountered neb­ challenging but achievable task for most amateur astron­ ulous objects that were not comets. Some of these objects omers to observe all the Messier objects. At «star parties" were his own discoveries, while others had been known and within astronomy clubs, going for the maximum before. In 1774 he published a list of 45 of these nebulous number of Messier objects observed is a popular competi­ objects. His purpose in publishing the list was so that tion. Indeed at some times of the year it is just about poss­ other comet-hunters should not confuse the nebulae with ible to observe most of them in a single night. comets. Over the following decades he published supple­ Messier observed from Paris and therefore the most ments which increased the number of objects in his cata­ southerly object in his list is M7 in Scorpius with a decli­ logue to 103 though objects M101 and M102 were in fact nation of -35°. He also missed several objects from his list the same. Later other astronomers added a replacement such as h and X Per and the Hyades which most observers for M102 and objects 104 to 110. It is now thought proba­ would feel should have been included.
    [Show full text]
  • Event Horizon Telescope Fact Sheet
    Event Horizon Telescope Fact Sheet The Event Horizon Telescope Collaboration The Event Horizon Telescope (EHT) is an international collaboration aiming to capture the first ever image of a black hole by creating a virtual Earth-sized telescope. This will test Einstein’s Theory of General Relativity in an extreme regime. The EHT consortium consists of 13 stakeholder institutes with about 200 participants in Europe, Asia, Africa, North and South America. The director of the EHT project is Dr. Sheperd S. Doeleman (Harvard- Smithsonian Center for Astrophysics). The technique applied for the EHT observations is called very-long-baseline interferometry (VLBI). VLBI enables the highest resolutions in astronomy by coupling a number of radio telescopes distributed across the Earth. This method is used for the investigation of the direct environment of supermassive black holes in the heart of active galaxies, in particular jets of high-energy particles emitted from the central regions. In the framework of the EHT project it will become possible to directly image the central black holes in addition to the jets. This is achieved by observations at shorter radio waves of only 1.3 mm wavelength. The resolution of the world-wide network of radio telescopes at that wavelength corresponds to the size of a tennis ball in the distance of the moon. To minimize the impact of the Earth’s atmosphere at that wavelength, the observations are only possible at high-altitude and dry sites like the Atacama desert in Chile, the Sierra Nevada in southern Spain, high volcanoes at Hawaii or even the South Pole.
    [Show full text]
  • QUANTUM GRAVITY and the ROLE of CONSCIOUSNESS in PHYSICS Resolving the Contradictions Between Quantum Mechanics and Relativity
    1 QUANTUM CONSCIOUSNESS RESEARCH LIMITED QUANTUM GRAVITY and the ROLE of CONSCIOUSNESS in PHYSICS Resolving the contradictions between quantum mechanics and relativity Sky Darmos 2020/8/14 Explains/resolves accelerated expansion, quantum entanglement, information paradox, flatness problem, consciousness, non-Copernican structures, quasicrystals, dark matter, the nature of quantum spin, weakness of gravity, arrow of time, vacuum paradox, and much more. 2 Working titles: Physics of the Mind (2003 - 2006); The Conscious Universe (2013 - 2014). Presented theories (created and developed by Sky Darmos): Similar-worlds interpretation (2003); Space particle dualism theory* (2005); Conscious set theory (2004) (Created by the author independently but fundamentally dependent upon each other). *Inspired by Roger Penrose’s twistor theory (1967). Old names of these theories: Equivalence theory (2003); Discontinuity theory (2005); Relationism (2004). Contact information: Facebook: Sky Darmos WeChat: Sky_Darmos Email: [email protected] Cover design: Sky Darmos (2005) Its meaning: The German word “Elementarräume”, meaning elementary spaces, is written in graffiti style. The blue background looks like a 2-dimensional surface, but when we look at it through the two magnifying glasses at the bottom we see that it consists of 1-dimensional elementary “spaces” (circles). That is expressing the idea that our well known 3-dimensional space could in the same way be made of 2- dimensional sphere surfaces. The play with dimensionality is further extended by letting all the letters approach from a distant background where they appear as a single point (or point particle) moving through the pattern formed by these overlapping elementary spaces. The many circles originating from all angles in the letters represent the idea that every point (particle) gives rise to another elementary space (circle).
    [Show full text]
  • Chandra Captures X-Rays in Coordination With
    National Aeronautics and Space Administration National Aeronautics and Space Administration ILLUSTRATION M87: Chandra Captures X-rays in Coordination with EHT The Event Horizon Telescope (EHT), a network of radio antennae around the globe, captured the first image of a black hole event horizon. This black hole is located in Messier 87, or Chandra can view the full length of the jet of M87, which is about 60 million light years high-energy particles launched by the intense from Earth. NASA’s Chandra X-ray Observa- gravitational and magnetic fields around the tory studied M87 many times over its 20-year black hole at M87. This jet (seen in detail from mission so far and sees a much wider field-of- Chandra, below left), extends more than 1,000 view than the EHT. In the image below, the “+” light years from the center of the galaxy. marks the spot in the Chandra image on the This dark portrait of the event horizon was left for the location of the EHT image on the obtained of the supermassive black hole in the right (not to same scale). center of the galaxy Messier 87 by the Event Astronomers used Chandra to obtain data of Horizon Telescope (EHT), an international M87 during the April 2017 observing run by collaboration. It took a remarkable effort and the EHT. These X-ray data, in combination coordination from scientists and organizations with the radio image from the EHT and other around the world to even have a chance to observations, will help scientists learn more make this happen.
    [Show full text]
  • Arxiv:1905.07378V4 [Astro-Ph.CO] 19 Jan 2020 Cosmic Accelerated Expansion
    Black hole shadow with a cosmological constant for cosmological observers Javad T. Firouzjaee1∗ and Alireza Allahyari2y 1Department of Physics, K.N. Toosi University of Technology, Tehran 15875-4416, Iran, School of physics, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran, Iran 2School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran, Iran Abstract: We investigate the effect of the cosmological constant on the angular size of a black hole shadow. It is known that the accelerated expansion which is created by the cosmological constant changes the angular size of the black hole shadow for static observers. However, the shadow size must be calculated for the appropriate cosmological observes. We calculate the angular size of the shadow measured by cosmological comoving observers by projecting the shadow angle to this observer rest frame. We show that the shadow size tends to zero as the observer approaches the cosmological horizon. We estimate the angular size of the shadow for a typical supermassive black hole, e.g M87. It is found that the angular size of the shadow for cosmological observers and static observers is approximately the same at these scales of mass and distance. We present a catalog of supermassive black holes and calculate the effect of the cosmological constant on their shadow size and find that the effect could be 3 precent for distant known sources like the Phoenix Cluster supermassive black hole. I. INTRODUCTION Recent observations of black holes shadow at a wavelength of 1.3 mm spectrum succeeded in observing the first image of the black hole in the center of the galaxy M87 [1, 2].
    [Show full text]