We are all Cosmologists. Cosmologists concern themselves with theories about the origins and ultimate fate of the universe. So, indeed, we are all cosmologists, because we all have at one time or another thought, "Where did we come from? Are we just stardust? Did the Big Bang really happen?"
Podcast To Come
April 5, 2018
Chuck Hailey from Columbia University is searching for a vast swarm of black holes, called a DENSITY CUSP, that he believes should exist around the central supermassive black hole in our Milky Way, Sagittarius A* (Sag A*). Trouble is, he cannot find this swath, or DENSITY CUSP. Hailey theorizes that in a 6 light year diameter around Sag A*, there should be 10,000 - 20,000 solar mass black holes floating around. Currently, though, only 5 dozen (~60) solar mass black holes are know to exist in our galaxy, and that's with a Milky Way diameter of 100,000 light years. It is difficult to spot black holes, and till now, there presence has only been inferred by indirect methods. Hailey is now looking for less-energetic sources of X-ray emissions around Sag A*, to locate these so-called missing solar mass black holes. Black holes are difficult to find, and since Sag A* is 26,000 light years from Earth, this makes them all the more difficult to locate. In the next story, astronomers from the University of Toronto, and Yale University, have found a galaxy which they believe contains very little, or no, dark matter. The galaxy is known as NGC 1052-DF2. Dark matter is the stuff which builds galaxies. Its gravity pulls all the mass of stars together to form the galaxy. An analogy: its like having a cup of coffee, but without the cup. If someone were to pour coffee onto a table, then the coffee would spill everywhere; on the table, on the floor, on the books. There would be nothing to hold the coffee together, and the results would just be pools of coffee splattered everywhere. Astronomers therefore are puzzled that NGC 105-DF2 is holding itself together, because there is very little, or next to no, Dark Matter in this galaxy. The weight of the galaxy is 1/400 of the weight that astronomers believe it should have, so it seems that the dark matter is missing from this galaxy. Dark matter and dark energy cannot be seen, and it is believed that 95% of our universe is either dark matter or dark energy. The normal matter that we can see only makes up 5 % of our universe. So astronomers are wondering how this galaxy could have formed, and how it could still be held together, without any dark matter there to do the holding. Its like coffee without the cup. But the galaxy is still somehow holding itself together, even though it is a diffuse galaxy. In fact, astronomers can see right through the galaxy, to the background stars and galaxies behind NGC 1052-DF2. It has tagged as being a "FLUFFY GALAXY", or a "UDG", and Ultra Diffuse Galaxy. Researchers are looking for others galaxies like NGC 1052-DF2 to try to explain how this peculiar galaxy came to form, or how it is holding itself together, without dark matter. Its like coffee without a cup, or a skyscraper without its supports, or the human body without its skeleton.
May 31, 2018
Intro Einstein and his super large enormous brain, and how he figured out all of these difficult theories. Astronomers have determined why relativistic particles are flying through the Van Allen Radiation Belts. Electromagnetic waves, called chorus waves, speed up particles, just like an adult's hand would when speeding up a child on a swing, by pushing the swing. The chorus waves are thought to continuously push the particles to relativistic speeds. Astronomers would like to know the cause of the acceleration of the particles so they can learn more about the radiation in the Van Allen Belts, something which is hazardous to spacecraft and astronauts which pass through the belts. A lonely neutron star has been found in the Large Magellanic Cloud, about 200,00 light years from us. Images are shown in X-ray, from the Chandra X-Ray Observatory, and visible light from Hubble nd the Very Large Telescope (VLT) in Chile. The debris around the corpse neutron star is rich in oxygen, and scientists are studying E0102 because they want to learn more about how massive stars fuse lighter elements into heavier ones before they explode. Seen up to a few thousand years after the original explosion, oxygen-rich remnants contain the debris ejected from the dead star’s interior. Also, astronomers have released the most completer survey of nearby stars and galaxies. The stars studied are all bigger than the sun, and are from 11 - 58 million light years from us. The galaxies were chosen for study based on their mass, star-formation rate, and abundances of elements that are heavier than hydrogen and helium. The data provide detailed information on young, massive stars and star clusters, and how their environment affects their development. from among 500 galaxies, compiled in ground-based surveys, located between 11 million and 58 million light-years from Earth. Team members chose the galaxies based on their mass, star-formation rate, and abundances of elements that are heavier than hydrogen and helium. The star cluster catalogs contain about 8,000 young clusters whose ages range from 1 million to roughly 500 million years old. These stellar groupings are as much as 10 times more massive than the largest clusters seen in our Milky Way galaxy. Astronomers hope to form the most complete catalog of star clusters and a stellar catalog in ultraviolet light. Ultraviolet light is a major tracer of the youngest and hottest star populations, which astronomers need to derive the ages of stars and get a complete stellar history. The synergy of the two catalogs combined offers an unprecedented potential for understanding star formation.
May 24, 2018
The Insight Spacecraft has to deal with as many 6 course corrections on its way to Mars. NASA has to keep Insight free from contaminants, so this affected the way Insight was launched. The course corrections are therefore necessary to get Insight in the right place at the right time, when it eventually gets to Mars in later October. Scientists are discovering the bounty of solar mass black holes that are thought to exist around our galaxy's central, supermassive black hole, Sgr A* The Chandra X-Ray observatory is doing the necessary snooping, to locate these black holes. NASA's Magnetospheric Multiscale spacecraft — MMS, is also discovering fascinating things about the magnetic happenings in Earth's magnetosphere. Magnetic reconnection, a complicated process which takes place in Earth's magnetosphere, has an affect on space weather, and therefore the weather on Earth. MMS is finding out interesting things about magnetic reconnection in near-Earth space.
April 26, 2018
Intro to Wormholes. A supernova, 2001ig, in galaxy NGC 7424, 40 million light years away, has been spotted with a surviving companion star. This proves that some supernovas originate in double-star systems. The majority of massive stars are in binary pairs, and many of these binary pairs will interact and transfer gas from one star to the other when their orbits bring them close together. The companion siphoned off almost all of the hydrogen from the doomed star’s stellar envelope, the region that transports energy from the star’s core to its atmosphere. Millions of years before the primary star went supernova, the companion’s thievery created an instability in the primary star, causing it to episodically blow off a cocoon and shells of hydrogen gas before the catastrophe. How stripped-envelope supernovas lose that outer envelope is not entirely clear. They were originally thought to come from single stars with very fast winds that pushed off the outer envelopes. The problem was that when astronomers started looking for the primary stars from which supernovas were spawned, they couldn’t find them for many stripped-envelope supernovas. Now they have. Astronomers hope to use the James Webb Space Telescope in the future to study this pair in more detail. A brief discussion of multi-star systems. Details are published in the March 2018 issue of Astrophysical Journal. Thanks for visiting Giorgio.
April 19, 2018
An asteroid bigger than the one that exploded 100 years ago in Russia's Tunguska region in Siberia gave Earth a close shave on Sunday April 15, just 1 day after it was first spotted. Asteroid 2018 GE3 made its closest approach to Earth at 2:41 a.m. EDT, whizzing by at a distance of 119,400 miles, or half the average distance between Earth and the moon, according to NASA's Center for Near Earth Object Studies. The asteroid, discovered just 1 day before it whizzed past Earth, is 6 times the size of the asteroid that leveled 500,000 acres of Siberian forest over Tunguska in 1908. 2018 GE3 is 3 times bigger than the asteroid that caused a lot of damage when it broke up 58 miles from Chelyabinsk, Russia, in 2013. It could have caused a lot of regional damage if it hit. Another asteroid also just nicked Earth in April. Now, lets talk about wormholes. Wormholes seemed to be more in vogue a few decades ago. Wormholes are theoretical constructs, or bridges, that could theoretically connect different parts of the universe, so that space travelers could travel very vast distances in a very, very short time, allowing for faster than light travel. Some theorists believe special exotic matter is necessary to prop open the mouth of the wormhole. Travelers could then travel through the bridge or portal that wormholes create, to other distance parts of the universe, or to other universes. A wormhole represents 1 solution to Einstein's equations of General Relativity. Some scientists actually believe wormholes in our Milky Way are casting shadows. The shadows would be tiny, so scientists are using the Event Horizon Telescope to detect these shadows. Wormholes are thought to cast bigger, more distorted shadows than black holes. (Hmmm, heady stuff). The detection of wormholes could provide an alternative explanation to gravity.
May 10, 2018
Neutrinos are sometimes called ghost particles because they are difficult to trap, or locate. If your thumb is perpendicular to the sun, then about 65 billion neutrinos are going through your thumb each second. Neutrinos are produced in the heart of the sun, in supernova explosions, in nuclear reactions, and in a few other ways. Neutrinos are almost massless, they carry 1/2 integer spin, and they interact only through the weak force and gravity. It was long of matter of debate for physicists whether neutrinos even had mass, but Canadian physicist Dr. Art MacDonald of the Sudbury Neutrino Observatory received a Nobel prize in physics in 2015 for proving that neutrinos do have mass. Since neutrinos can oscillate between different flavors, or kinds, that was the necessary item needed to prove they have mass. Neutrino physics took off in 1987 when neutrinos from Supernova SN1987A were detected on Earth, just before the light from the SN reached us.
November 23, 2017
Review: pulsars help detect gravitational waves. Also, Hubble is viewing a galaxy merger. Galaxy NCG 2623, or Arp 243, 250 million LYs away in Cancer. The merging galaxy has an irregular shape, and star formation is prominent, marked by the bright blue glow of parts of the galaxy. When galaxies merge, dust and gas is stirred and becomes turbulent, resulting in increased star formation. The 2 separate galaxies harbored super-massive black holes before the merger, so they will surely merge in the future. Also, whistling electrons are in orbit around Earth, in its Van Allen Belts. Fluctuating magnetic and electric fields cause the electrons to be lost from Earth's atmosphere. These high energy electrons are known as, Whistler Mode Chorus. The electrons chirp in rising tones, much like birds do. Results, Geophysical Review Letters. 15:00:30 15:29:10
November 16 , 2017
Serving ice-cream and pizza on the International Space Station. Venus and Jupiter closely aligned in the morning of November 13, 2017. Pulsars are being used to track G Waves. Gravitational waves are ripples in space-time, created from colliding black holes or neutron stars, amongst other things (and from masses accelerating in space). G waves also come from BHs or NS as they circle each other, before merging. Most galaxies harbor super-massive black holes at their centers. 2 merging super-massive black-holes produce low-frequency G waves. These types of G waves have not yet been detected. (super massive BHs can weigh a million or billion solar masses). To find these G waves, astronomers are using pulsars. Pulsars are neutron stars that spin very fast, so they emit many radio wave pulses each second (some spin hundreds of times each second). The North American Nanohertz Observatory for Gravitational Waves (NANOGrav) is doing the search. A pulsar, or pulsar timing array, emits radio waves in a predictable pattern, so if a G wave hits the pulsar, the distortion in space-time of the G waves can be measured from the distortion of the pulse from the pulsar. LIGO detects G waves just seconds before 2 black holes or neutron stars merge, but it can take millions of years to merge. While they're in a cosmic death dance around each other, G waves are emitted. LIGO cannot detect these waves, but scientists believe pulsars can help.
2 LIGO stations and the Virgo detector detected Gravitational waves, named GW170817, on August 17 2017, from the collision of 2 neutron stars in NGC 49933, 130 Million LYs away. This was the 5th detection of G waves, but in this 5th instance, other radiation was also detected. The 4 detections from black hole collisions found only G waves, because light cannot escape a black hole. But in this collision of 2 neutron stars, radio, light, and other types of waves were detected. Another feature of the August 17 event was how long it lasted. The first 4 black hole events lasted for a few mere seconds, but the 5th event lasted about 100 seconds, at frequencies climbing to 1000s of hertz. The colliding neutron stars weighed 1.4 and 1.6 solar masses. NASA's Fermi Gamma Ray Space Telescope picked up a flood of gamma rays just seconds after the collision. Other observatories around Earth also detected the electromagnetic radiation just after the event, so a number of observatories jumped in and monitored it in many different wavelengths. A high level of collaboration let scientists pinpoint the event, in NGC 4993. Generations of heavy elements was also detected.
3 BIG FINDS: the event
1. explains the origins of short gamma ray bursts, short GRBs.
2. reveals the occurence of a kilonova
3. solved the puzzle of elements produced in the R Process, (R = Rapid), as the event produced heavy nuclei.
The neutron star collision also raised other questions. The GRBs were relatively faint: listen to hear why. May the force be with us all as we wait for more G wave events.
October 19, 2017
Light cannot escape a black hole, so when LIGO first detected the collision of 2 black holes , they only detected gravitational waves. But when 2 neutron stars (130 million light years away, in galaxy NGC 4993) collided, and Earth received the signal August 17, 2017, G waves, and an array of electromagnetic radiation were detected. Astronomers were able to confirm their theories on many aspects of neutron stars from the event. The newspaper the Independent claims, " the event has kickstarted a "new chapter in astrophysics and confirmed theories about the origin of the mysterious neutron stars". The formation of many precious and heavy metals were also detected from the collision. This kilonova, 1000s of times stronger than a mere nova, flung out a whole host of knowledge, along with G waves, electromagnetic radiation, gold, plantinum and lanthanides, among other heavy elements. The colliding neutron stars weighed 1.4 and 1.6 solar masses. This was the first detection of G waves from anything other than black holes. The neutron stars stretched and warped space-time as they approached each other. A burst of short gamma ray bursts, short GRBs, was detected 2 seconds after the detection of the g waves. The event also was detected for 100 seconds, whereas in the collision of black holes, the 4 previous events lasted for at most 2 seconds. When the event, GW170817, occurred, dinosaurs ruled the Earth. Findings are in the journals, Nature, Nature Astronomy and Physical Review Letters. The collision answered 3 questions about neutron stars: (1) what happens when neutron stars merge (2) what causes short duration gamma ray bursts (GRBs) (3) where heavy elements like gold are made. Astronomers feel this is a new chapter in astrophysics. Dr. BS Sathyaprakash, Cardiff University, said the 12 hours following the collision of the neutron stars was the most exciting period of his entire scientific life. The collision also helped astronomers more accurately measure the expansion rate of the universe. It will help explain the inner workings of neutron stars, and confirm theories in general relativity.
Dr. Chris Ruiz is an astrophysicist. He specializes in research in
determining nuclear reaction rates for stellar nucleosynthesis.
June 8, 2017
Astronomers using Chandra are studying a MIra type star, a type of symbiotic star, which co-exists with another star. R Aquair, or R Aqr, 710 light years away, is emitting blobs of X-ray emissions. It is a cool, red giant star (a Mira variable star), orbiting a dense white dwarf. The red giant is pulsating and its brightness can change by a factor of 250. The surface temperature of the white dwarf is 20,000 degrees, while the red giant measures in at 3,000. The 2 stars are comparable in mass, but since the WD is much more compact, it is much more dense. This means it has a stronger gravitational tug, and is therefore pulling off gas from the red giant, and onto itself. This resulted in nova explosions on the WD in 1073 and 1773. Scientists believe NOVA explosions occurred on the WD in the early 2000s, in the 1950s and 1980s. With the NOVA, matter is ejected from the WD at 10 million miles per hour. With this, a ring of ejecta is seen. The NOVA explosions are thought to give rise to 2 jets of X-ray emissions that stream away from the pair of stars at 1.4 & 1.9 millions miles per hour. With these observations, scientists are trying to understand the volatile relationships that can occur between pairs of stars like these.
June 1, 2017
A bizarre dance of electrons has been detected in Earth's magnetosphere. Electrons will travel in spiral patterns around strong magnetic filed lines. In weak magnetic fields, the electrons wag around in a free style motion. NASA has uncovered what the electrons do in intermediate strength magnetic fields. The motion is a combination of spiraling and meandering, before the electrons are ejected into space, with large amounts of magnetic energy. NASA'S Magnetospheric Multiscale Mission (MMS) studied the electrons in intermediate strength fields, in a process called magnetic reconnection. Magnetic reconnection occurs in the sun, where large amounts of energy, stored for days or hours, are released. The magnetic field environment where the electrons’ motions were observed was uniquely created by magnetic reconnection, which caused a current sheet (through which the electrons travel) to be tightly confined by bunched-up magnetic fields. The electrons then travel in large spirals, before they are finally ejected, along with enormous amounts of stored magnetic energy. The research sheds light on the role of electrons in reconnection, and how magnetic fields lose energy. Magnetic reconnection is an important process in the universe, and some of the universe's most explosive releases of energy occur through magnetic reconnection. With this research, scientists are gaining knowledge of our magnetic environment, and its affect on spacecraft and satellites. MMS obtained their data with a daring flight of 4 spacecraft through the Earth's magnetosphere.
July 6, 2017
With help from the Hubble Space Telescope (HST), scientists have viewed a distant cluster of galaxies, that has been microlensed, and then captured by HST's lens. J143450.5+033843 lies 11 billion light years away, and without the aid of gravitational lensing and HST, it would not be visible. The light of the faint galaxy is being magnified by a cluster of foreground, or closer, galaxies. The strong gravity of the galaxy cluster acts as a magnifier, multiplying the light intensity coming from this far away galaxy. Presently, HST is only able to image the younger stars in this galaxy, but when the James Webb Telescope becomes operational, JSWT will be able to image the older stars in the galaxy. As for Hubble, the images it would produce would seem unremarkable without the lensing effect. Astronomers would not be able to make out or spot the hundreds of galaxies, or the knots of galaxies, as astronomers are calling them. Knots of stars, forming in galaxies 200 - 300 light years across are now visible. Without the lensing and HST, the light would appear to be smooth; so the formation of the stars would not be visible.
April 20, 2017
A large elliptical galaxy, NGC 4696, 145 light years away, lurks at the heart of the Centaurus galaxy cluster. And hiding deep in the heart of NGC 4696, lurks a massive black hole. Even though black holes are known to devour matter around them, this particular black hole is pumping energy into the galaxy around it. The bursts of energy are thought to occur every 5 - 10 million years. The bursts create cavities in the hot gas that inhabits the space between neighboring galaxies. Sonic booms, measured to travel tens of thousands of light years, are also created when the black hole pumps out its energy. The process is being imaged by the Chandra Observatory in x-rays, Hubble in visible light, and in radio from the Very Large Array Telescope. When the images are combined, astronomers get a better picture of what is going on. Chandra was used to highlight 9 special cavities in the hot gas. Astronomers have also measured the "pitch" of the resonance in the cavities, and have marked it as having a note near middle C. The hot gas that fills the cluster of galaxies has allowed the sound to travel. The black hole bursts seem to be full of elements that are generated in previous supernova explosions in NGC 4696. Oddly, the energy coming from the black hole has prevented the gas around it from cooling. New stars form from cool gas, so the higher temperature of the gas has prevented large numbers of stars from forming in the vicinity of the black hole. A different type of processing of the X-ray data reveals a sequence of curved and approximately equally spaced features in the hot gas. These may be caused by sound waves generated by the black hole’s repeated bursts. In a galaxy cluster, the hot gas that fills the cluster enables sound waves – albeit at frequencies far too low for the human hear to detect – to propagate.
February 2, 2017
Blazars are very compact quasars (quasi-stellar radio sources) associated with presumed super-massive black holes. They are located at the center of active, giant elliptical galaxies. Blazars are among the most energetic phenomena in the universe. Scientists working with NASA's Fermi Gamma Ray Telescope have detected a blazar that breaks the record for the most distant blazar ever detected. The previous record holder sent its light toward Earth when the universe was only 2.1 Billion years old, but with this newly discovered blazar, its light has been coming toward Earth for 12 billion years (when the universe was 1.3 billion years old). In this galaxy, light and matter is pulled toward the central black hole, then gathers in an accretion disk, like cars gather on a road in a traffic jam. The matter heats up, and when it falls into toward the black hole, a small amount gathers and gets redirected into 2 particle jets, which shoot the matter out in opposite directions, along the central axis of rotation of the galaxy. When either of these jets is direct into the direction of the the Earth, scientists can detect the jet. The energy output of the accretion disk has the output equivalent to 2 trillion times the energy output of our Sun. Scientists are surprised that a massive black hole such as this one, which is billions times the mass of our Sun, could have formed at such an early stage in our universe. They are now trying to determine what caused the rapid development of this black hole. Scientists also detected 4 other blazars which appeared on a time scale when our universe was only 1.4 - 1.9 billion years old. Two of these blazars are powered by black holes that have the mass of more than 1 billion Suns. The detection of these blazars at such an early stage in the universe challenges some of the models that now describe how black holes formed and grew.
November 10, 2016
By observing a super-massive black hole in the center of a galaxy (with Hubble and Chandra) during the past 10 years, scientists feel the BH is no longer being fed enough fuel to make its surroundings shine brightly. Many galactic cores shine brightly due to the presence of super massive BHs feeding on surrounding matter. These active galactic nuclei or AGN, are amongst the brightest things in the universe. They are powered by matter that falls into a BH. Scientists are unsure as to the cause, but the infall of matter into the nucleus is being disrupted by some unknown process. NASA and FEMA are planning emergency response exercises in case an asteroid impacts Earth. NASA monitors asteroids near Earth orbit, and also asteroids in longer orbits, so emergency response exercises are being simulated for an asteroid impact. Hubble is viewing a galaxy, NGC 1222, a peculiar example of a lenticular type galaxy, swallowing up 2 dwarf galaxies in orbit around it. The gas falling in is likely the agent triggering starbursts and star formation in NGC 1222. The moral of the story: don't stray too close to a big galaxy, or you will be ripped apart. AGN are classified into 2 main types based on the properties of the light they emit. One type of AGN is brighter than the other. The brightness is thought to depend on either or both of 2 factors: the AGN could be obscured by surrounding gas and dust, or it could be intrinsically dim because the rate of feeding of the supermassive black hole is low. Some AGN change once between these 2 types over the course of only 10 years, a blink of an astronomical eye. But the AGN associated with the galaxy Markarian 1018 stands out by changing type twice, from a faint to a bright AGN in the 1980s and then changing back to a faint AGN in the last 5 years. A handful of AGN make this full-cycle change, but never before has one been studied in such detail. During the second change in type the Markarian 1018 AGN became 8 times fainter in X-rays from 2010 - 2016.
Dr. Reiner Krueken is a research physicist at the TRIUMF facility at UBC. He specializes in neutron rich reactions in stellar supernovas.
Dr. Ingrid Stairs is an astronomer and professor at the University of British Columbia. Dr. Stairs specializes in neutron star research. We talk about her research work on measuring the space-time warp created by a pair of binary neutron stars orbiting one another.
May 22, 2014
Dark Matter and Dark Energy discussion. The orbital speeds of gas, stars and matter in the outer reaches of a galaxy, rotate at the same speed as gas, stars and matter in the inner reaches of a galaxy. This should be so. Learn what role dark matter and dark energy have in shaping our universe.
May 15, 20114
What are black holes? How are they formed? I will distinguish between black holes produced by core-collapse supernova, and black holes at the centers of galaxies. Our sun will not go supernova at the end of its life-cycle, but will instead become a carbon white dwarf. The life stages and fates of stars of different sizes will be discussed, as well as the processes in a supernova. I'll also talk about the relatively associated with black holes, event horizons and space-time.
Death Stars, Black Holes, Magnetar SGR 104
and Pulsar PSR B1919+2
May 1, 2014
Customers have questions, you have answers. Display the most frequently asked questions, so everybody benefits.