How Far Away Is It - 2017 Review - Gamma Ray Bursts

hello and welcome to our 2017 review 2017 was another really good year and it had a number of interesting bursts we'll see the first asteroid that we've detected that came from outside our solar system swiggy transient facility that we talked about last year saw its first light this year we saw for the first time an ancient dead galaxy that was not elliptical it was spiral which has some interesting implications we saw a type 1a supernova companion star for the first time we've been looking for that for ages we even saw a star fall into a black hole without a supernova and one of the most interesting things this past year was that we saw merging neutron stars coalescing but we'll start close to home with a new picture from Hubble of Jupiter on April 7th Jupiter was in opposition with the hemisphere facing earth fully illuminated by the Sun this Hubble image reveals the intricate detailed beauty of Jupiter's clouds as arranged into bands these bands are produced by air blowing in different directions at various latitudes lighter colored areas called zones experience high pressure where the atmosphere Rises darker low pressure regions where air falls are called belts constantly stormy weather occurs where these opposing east to west and west to east winds interact recent Hubble observations of Jupiter's icy moon Europa have uncovered a probable plume of material erupting from the moon's surface the plume went about 100 kilometres above Europa's surface at 62 miles it happened at the same location as a similar apparent plume erupted two years earlier these plumes are consistent with the idea that Europa has an ocean of water under a thick layer of ice although it is quite cold on the icy surface at 92 degrees Kelvin that's minus 289 degrees Fahrenheit other studies have found that there is an area of relatively warmer temperatures in the same region where the plumes are located if there is a causal link between the plumes and the thermal anomaly there could be geologic activity on Europa's surface that is producing the plumes this would also provide the energy for life given all this a new mission has been funded to send a spacecraft called the Europa clipper to Jupiter with the instruments needed to study Europa in greater detail it is scheduled for launch in the 2020s in October 2017 a team from the pan-starrs Observatory in Hawaii detected a very unique object traveling on a hyperbolic path through our solar system subsequent observations by a variety of telescopes using spectroscopy and brightness curves found it to be a reddish grey elongated asteroid tumbling lengthwise the object approached our solar system from almost directly above the ecliptic that's the plane in space where the planets and most asteroids orbit the Sun its path indicates that it came from outside our solar system on September 2nd the small body crossed under the elliptic plane just inside Mercury's orbit and then made its closest approach to the Sun on September 9th at that point is perihelion it was traveling at 89 kilometers per second that's 55 miles per second relative to the Sun at that velocity it is definitely not gravitationally bound to the Sun pulled by the star's gravity the object made a hairpin turn under our solar system passing under Earth's orbit on October 14th at a distance of 24 million kilometers that's 15 million miles about 60 times our distance from the moon it is now shot back up above the plane and is speeding towards the constellation Pegasus Kyah continues its work creating a three-dimensional map of billions of stars with unprecedented positional and radial velocity measurements a full data release is due in 2018 this past year Gaia released 14 months worth of data on the Large Magellanic Cloud one of the nearest galaxies to our Milky Way this image is based on stellar density it shows the large-scale distribution of stars in the LMC clearly delineating the full extent of the spiral arms it is peppered with bright dots each representing a faint cluster of stars this image is based on total luminosity it is dominated by the brightest most massive stars which greatly outshine their fainter lower mass counterparts in this view the bar of the LMC is outlined in greater detail alongside individual regions of star formation like the bubbling tarantula nebula here are a few views in visible light from ground-based telescopes [Music] [Music] here we are zooming into the sculptor dwarf galaxy an elliptical spheroidal galaxies orbiting the Milky Way in 2017 Gaia and Hubble provided datasets separated by 12 years that were used to measure the exact three-dimensional motion of a small number of sculptors stars the main goal was to examine the distribution of dark matter in a galaxy without a central bar like our own the current theory has it that dark matter is cold and only interacts with itself and visible matter via gravitational forces statistical simulations indicate that matter with these properties would clump up into galaxies with the dark matter density being highest in the center this peak density at the center is referred to as a dark matter cusp but spheroidal galaxies like this one don't have core dense Center bars so the central question became does this galaxy have a dark matter cusp even though it has no visible core if the answer is no as expected by many then we go back to the drawing board for figuring out dark matter 126 stars were found in common in the two hubble pointings and the gaia data set using star distance the researchers identified 91 of these that were actually inside sculptor using only those stars with the most accurate motion readings brought the number down to 15 stars over the 12 years they would have traveled on average only 6 10 thousandths of a Lightyear and sculptors own reference frame the results show that the stars and sculptor move preferentially on elongated radial orbits this indicates that the density of dark matter increases towards the center instead of flattening out these findings are in agreement with the established Dark Matter model but the data set is very small and more research is needed before a definite answer to our question can be reached three decades ago astronomers spotted one of the brightest exploding stars in more than 400 years the Titanic supernova called 1987a in the Large Magellanic Cloud blazed with the power of a hundred million suns for several months following its discovery a dense ring of gas around the supernova is glowing in optical light and has a diameter of about one Lightyear a flash of ultraviolet light from the explosion energized the gas in the ring making it glow for decades this time-lapse video sequence of Hubble images show the effects of the shock wave from the supernova blast smashing into the ring the ring begins to brighten as the shock wave hits it in the past few years the Rings x-ray light has stopped getting brighter and the bottom left part of the ring has started to fade these changes provide evidence that the explosions blast wave has moved into the region beyond the ring this represents the end of an era for the supernova we expect to learn more about the new region as the blast wave impacts its contents most supernova explosions involve just one star but type 1a supernovae involve a binary star system with a normal star and a white dwarf but no one has ever found an exploding stars companion in 2017 a group of astronomers used Hubble to study the remnant of the type 1a supernova explosion n1 o3 be located in the LMC where they may have finally found one using the exploding stars remnant curved shock fronts they located the center of the explosion and found a candidate star nearby the star has the right temperature luminosity and distance from the center of the original supernova explosion although this star is a reasonable contender for n 103 bees surviving companion its status cannot be confirmed yet without a spectroscopic confirmation the research is still ongoing here we are panning across the climb and low nebula 1300 light-years away at the heart of the orion molecular cloud it is the most active star-forming region in orion cloaked in dust the stars of Kleinman law are only visible in infrared light decades ago researchers found two stars labeled B N and I traveling at high speeds in opposite directions they trace both stars back 540 years to the same location this suggested that they were part of a multiple star system but the duo's combined energy which is propelling them outward didn't add up the researchers reasoned that there must be at least one other star that took kinetic energy from the other two while searching for rogue planets and brown dwarfs among the turbulence astronomers have found a star labeled X moving at an unusually high speed about two hundred thousand kilometers per hour that's almost 30 times the speed of most of Orion stars it's thought that this star might be the missing piece of the star system if this is the missing star it might shed light on just what caused the three star system to break apart in the first place in the year 14 77 the large binocular telescope LBT for short in Arizona was scanning the fireworks galaxy 22 million light-years away looking for supernova candidates they examine the star named n 69 46 - BH 1 a star 25 times more massive than our Sun stars the size usually end in a supernova explosion leaving behind a neutron star or a black hole here's a graph of the star's luminosity in visible and infrared light over time in 2007 Hubble took this picture of the star in 2009 the star shot up in brightness to become over 1 million times more luminous than our Sun for several months the expectation was it was about to supernova but it didn't it just seemed to vanish as seen in this image from 2015 after the LBT turned up the star astronomers aim the Hubble for visible light and Spitzer for infrared light to see if the star was still there all tests came up negative the star was no longer there the researchers eventually concluded that the star must have become a black hole without a supernova we covered Palomar observatory's news wiki transient facility ztf for short in our 2016 review it's a robotic camera with the ability to capture hundreds of thousands of stars and galaxies in a single shot in 2017 ztf took its first image of the sky and event astronomers referred to as first light this first light image of orion is a taste of what's to come every night CTF will scan a large portion of the northern sky discovering objects that erupt move or varying brightness including asteroids comets and supernovae each image is more than twenty four thousand by twenty four thousand pixels and four terabytes of data will be collected each night ztf science survey phase is scheduled to begin in February you may recall that we use redshift to determine the galaxies receding velocity along with the inverse square law for standard candles like C feed variables and type 1a supernovae to determine a galaxy's distance combined they gave us Hubble's law and the Hubble constant in 2017 a Swedish led team of astronomers use the hubble space telescope to analyze multiple images of a gravitationally lens type 1a supernova this had never been done before here we see the lens galaxy in the middle frame it's over 2 billion light years away the four images of the supernova can be seen in the rightmost frame it originated over four billion light years away these four images of the exploding star and the time difference in their light profiles can be used to measure the Hubble constant in a completely different way since the light travel times for the various images are unequal intrinsic variations in the source would be observed at different times in the images the time delay between images is proportional to the difference in the light path lengths through the lens and galaxy space time which in turn is proportional to one over a Hubble constant so by measuring redshifts and time delays and by producing an accurate model for the lensing galaxy the Hubble constant can be calculated but measuring the lens properties of a galaxies billions of light-years away is difficult this is where most of the ongoing research is focused here are a few of the interacting galaxies photographed by Hubble in 2017 here we are zooming into Markarian 266 [Music] the odds structure of this galaxy is due to the fact that it is not one galaxy but two in the process of a galactic collision it is composed of two disk galaxies whose nuclei are currently just thirteen thousand light-years apart their constituent gas dust and stars are swirling together igniting newborn stars and bright star formation regions across the galaxy in addition each merging galaxies contains an active galactic nucleus or gas and other debris are fed into supermassive black holes here we see NGC 4490 and NGC 44 85 together they form the system ARP 269 twenty-four thousand light-years currently separates the two over millions of years their mutual gravitational attraction has dragged the two galaxies into each other in this image the two galaxies have moved through each other and are speeding apart again but the galaxies are likely to collide once more within a few billion years the extreme tidal forces of these interactions have determined the shapes and properties of the two galaxies 4490 was once a barred spiral galaxies like the Milky Way but now virtually no trace of its past spiral structure can be seen from our perspective the outlying regions have been stretched out resulting in it's nicknamed the cocoon galaxy here we're suing into tiny galaxy NGC 1510 and it's colossal neighbor NGC 1512 you [Music] the large galaxy to the left in this image is classified as a bar spiral the tiny galaxy to the right is a dwarf galaxy despite their very different sizes each galaxy affects the other through gravity causing slow changes in their appearances here's an image of two galaxies one is seen almost face-on and the other is edge-on they were observed by Hubble in 2017 to celebrate its 27th year in orbit in the face on galaxies we can see spiral arms and the blue patches of ongoing star formation and young stars in the edge-on galaxy we can see huge swaths of dust responsible for the molted brown patterns we also see a burst of blue to the left side of the galaxy indicating a region of extremely vigorous star formation their galaxy centers are 35,000 light-years apart at their closest point the galaxies are separated from each other by only 7,000 light years given this very close arrangement astronomers are intrigued by the galaxies of parent lack of any significant gravitational interaction the long tidal tails and deformations and other structures that are typical of galaxies lying so close together are missing completely when the universe was just three billion years old half of the most massive galaxies were extremely compact and had already exhausted their fuel for star formation the galaxy is said to be dead when it stops creating new stars they were elliptical and it is believed that they grew into the most massive local elliptical galaxies we see today through mergers with nearby galaxies in 2017 while scanning a distant galaxy cluster astronomers discovered the first example of a massive compact dead galaxies in the early universe that is not elliptical the foreground galaxy cluster has magnified the image to the more distant galaxies enabling a closer look than ever before the dead galaxy is in fact a fast spinning disc shaped galaxy it has three times the mass of the Milky Way but is only half the size and spinning at more than twice the speed this is the first direct observational evidence that at least some of the earliest dead galaxies somehow evolved from a Milky Way shaped disc into the giant elliptical galaxies we see today how this could happen is not yet understood gamma-ray bursts are the most energetic and luminous electromagnetic events in the universe they can release more energy in ten seconds then our Sun will emit in its entire 10 billion year expected lifetime to understand these events we need to take a closer look at gamma rays gamma rays of the highest energy form of light the wavelengths are smaller than the diameter of a typical atomic nucleus here's an example of a gamma ray photon created when an excited cobalt atomic nucleus decays to a lower energy level the gamma ray photon has 640 thousand times more energy than the yellow light photon and this is a relatively low energy gamma ray other sources are extreme conditions in our Milky Way and other galaxies some are generated by transient events such as solar flares and supernovas others are produced by steady sources like supermassive black holes that galaxy centers since June 2008 the Fermi gamma-ray Space Telescope has been scanning the entire sky for gamma rays every three hours here's an all-sky map as seen by Fermi the brighter gamma ray light is shown in yellow and progressively dimmer gamma ray light is shown in red and blue we see that the plane of the Milky Way is bright in gamma rays above and below the bright band much of the gamma ray light is coming from outside of our galaxy [Music] here's a full spectrum composite image of the Cassiopeia a supernova remnant note the strong gamma-ray emission area on the right gamma-ray energies up to seven trillion electron volts were measured here but the energy from sources such as these spread out in all directions and weakened in intensity according to our familiar inverse square law the gamma ray bursts gr B's for short first spotted in the 1960s are focused and remain intense even as they move across the cosmos lasting anywhere from a few milliseconds to several minutes they shine hundreds of times brighter than a typical supernova and about a million trillion times brighter than our Sun here's the farthest and most powerful GRB ever detected it occurred 12.2 billion light-years away as determined by visible after color light seen by the European Southern Observatory in Chile with a distance known the strength of the blast can be calculated this blast exceeded the power of approximately five thousand nine hundred type 1a supernovae by the late 90s ten gamma-ray bursts have been observed this was enough to distinguish two distinct types short usually around a second or less and long usually around 30 seconds to a couple of minutes it was thought that long duration bursts came from imploding stars collapsing into black holes these are referred to as superluminous supernova or hypernova or collapse ours this theory was confirmed in 1998 when g RB 98 o 425 was also found to be supernova 1998 BW in a spiral galaxy a hundred million light years away but there has never been any confirmation that short bursts from merging neutron stars that is until August 17 2017 on August 17th 2017 a gravitational wave traveling at the speed of light swept across the two LIGO interferometers and the new Virgo interferometer in Italy the wave was named GW 1708 17 you may remember from our segment on gravitational waves that the interferometer waveform amplitude frequency and change in frequency called its chirp give us a measure of the merging objects mass and distance this waveform indicated that the masses fit the profile for neutron stars and that the luminosity distance to the source was around 130 million light years location analysis from LIGO limited the direction of the event to too long area of the sky as you may have noticed the Virgo interferometer in Italy did not trigger on the event this indicates that the angle of impact was one of the four that would not be seen by an interferometer because the instruments arms are impacted in exactly the same way at exactly the same time this allowed us to narrow the sources location on the sky considerably 1.7 seconds after LIGO triggered the Fermi gamma-ray burst detector registered gamma-ray bursts GRB 1708 17a in an area of the sky that overlaps the area identified by like.oh and Virgo simultaneous detection by ESA s integral satellite helped narrow down the gamma-ray sources possible area of the sky that was completely consistent with the gravitational waves origin but there are a number of candidate galaxies for the neutron star collision in this area all at various distances from Earth but galaxy NGC 4990 3 a hundred and thirty million light-years away looked like a good candidate alerts went out to all observatories across the planet and in orbit then a simultaneous gravitational wave in gamma-ray bursts had been detected in this area of the sky within hours ground-based telescopes observed optical and near-infrared images of a bright light and named it SSS 17 a redshift data indicated that it was indeed coming from NGC 4990 3-4 days later it had faded significantly over the next six days Hubble captured images of the galaxies and visible and infrared light here's an image of the new bright object that faded noticeably over that time period this all represents powerful evidence that GW 1708 17 GRB 1708 17 a and SS SS 17 a are indeed caused by the same event the merger of two neutron stars the combining of gravitational wave detection and electromagnetic detection gives us a whole new avenue of astronomical study we'll finish our 2017 review with a trip through Hubble's ultra deep field this visualization traverses the candles ultra deep survey field to showcase the varied appearance of galaxies and their three-dimensional distribution the sequence features a dense cluster of galaxies about 6 billion light-years away and extends to galaxies at more than twice that distance the changes seen in galaxies during the fly through illustrate the change in galaxies structure and appearance over billions of years of cosmic history handfuls is one of the largest projects ever done with the Hubble Space Telescope astronomers and visual artists extracted over 26 thousand galaxies from the Hubble ultra-deep Survey and created a computer model based on the measured and estimated properties here are the links to the Hubble sites white papers and other locations where I found the information contained in this 2017 review these are also the places where you can go to begin to do your own research and don't forget every how far away is it video including this one as a document with the text pictures links and notes located on how far away is it calm slash documents thanks for watching [Music] you

Channel: David Butler

Views: 241,264

Rating: 4.8694944 out of 5

Keywords: STEM, astronomy, Jupiter, Europa, Gaia, Sculptor Dwarf Galaxy, dark matter, LMC, Supernova, gamma rays, GRB, black hole, gravitational wave, ligo, virgo

Id: l7N8AIsOt3o

Length: 33min 42sec (2022 seconds)

Published: Fri Feb 16 2018