miércoles, 23 de septiembre de 2020

Thuk Je Che Tibet - Inicio



TAKDROL



Este Tak Drol se fabricó hace años bajo la dirección de Lama Tharchin Rimpoché, y todavía está en nuevas condiciones.



El takdrol tiene forma cuadrada y está hecho de brocado rojo. Takdrol mide 2 1/2 x 2 1/2 pulgadas. El cordón satinado mide aprox. 17 1/2 pulgadas.

Takdrol es uno de los "cinco métodos que conducen a la liberación sin necesidad de meditación" y significa "liberación por contacto".

Existen numerosos tipos de takdrols: muchos son mantras en diagramas relacionados con las enseñanzas Dzogchen, y otros pertenecen a los tantras. El takdrol puede formar parte de un empoderamiento más detallado, o puede administrarse

independientemente como un empoderamiento simple por sí solo.



A veces, el texto de un tantra se usa como takdrol y se usa, por ejemplo, en un relicario en la parte superior de la cabeza.

Los Takdrols también se pueden colocar en el cuerpo de una persona fallecida después de la muerte, y enterrarse o quemarse con el cuerpo, para ayudar a aliviar su sufrimiento durante el bardo.

Hubble Makes Unexpected Dark Matter Discovery

Hubble Observations Suggest Missing Ingredient in Dark Matter Theories | NASA

Hubble Observations Suggest Missing Ingredient in Dark Matter Theories | NASA

Nasa

Hubble Observations Suggest 

a Missing Ingredient 

in Dark Matter Theories

Astronomers have discovered that there may be a missing ingredient in our cosmic recipe of how dark matter behaves.
They have uncovered a discrepancy between the theoretical models of how dark matter should be distributed in galaxy clusters, and observations of dark matter's grip on clusters.
Astronomers seem to have revealed a puzzling detail in the way dark matter behaves. They found small, dense concentrations of dark matter that bend and magnify light much more strongly than expected.
Credits: NASA's Goddard Space Flight Center
Dark matter does not emit, absorb, or reflect light. Its presence is only known through its gravitational pull on visible matter in space. Therefore, dark matter remains as elusive as Alice in Wonderland's Cheshire Cat – where you only see its grin (in the form of gravity) but not the animal itself.
One way astronomers can detect dark matter is by measuring how its gravity distorts space, an effect called gravitational lensing.
Researchers found that small-scale concentrations of dark matter in clusters produce gravitational lensing effects that are 10 times stronger than expected. This evidence is based on unprecedentedly detailed observations of several massive galaxy clusters by NASA's Hubble Space Telescope and the European Southern Observatory's Very Large Telescope (VLT) in Chile.
distant swirls of galaxies against the black backdrop of space
This Hubble Space Telescope image shows the massive galaxy cluster MACS J1206. Embedded within the cluster are the distorted images of distant background galaxies, seen as arcs and smeared features. These distortions are caused by the amount of dark matter in the cluster, whose gravity bends and magnifies the light from faraway galaxies. This effect, called gravitational lensing, allows astronomers to study remote galaxies that would otherwise be too faint to see. Several of the cluster galaxies are sufficiently massive and dense to also distort and magnify faraway sources. The galaxies in the three pullouts represent examples of such effects. In the snapshots at upper right and bottom, two distant, blue galaxies are lensed by the foreground, redder cluster galaxies, forming rings and multiple images of the remote objects. The red blobs around the galaxy at upper left denote emission from clouds of hydrogen in a single distant source. The source, seen four times because of lensing, may be a faint galaxy. These blobs were detected by the Multi-Unit Spectroscopic Explorer (MUSE) at the European Southern Observatory's Very Large Telescope (VLT) in Chile. The blobs do not appear in the Hubble images. MACS J1206 is part of the Cluster Lensing And Supernova survey with Hubble (CLASH) and is one of three galaxy clusters the researchers studied with Hubble and the VLT. The Hubble image is a combination of visible- and infrared-light observations taken in 2011 by the Advanced Camera for Surveys and Wide Field Camera 3.
Credits: NASA, ESA, P. Natarajan (Yale University), G. Caminha (University of Groningen), M. Meneghetti (INAF-Observatory of Astrophysics and Space Science of Bologna), the CLASH-VLT/Zooming teams; acknowledgment: NASA, ESA, M. Postman (STScI), the CLASH team
Galaxy clusters, the most massive structures in the universe composed of individual member galaxies, are the largest repositories of dark matter. Not only are they held together largely by dark matter's gravity, the individual cluster galaxies are themselves replete with dark matter. Dark matter in clusters is therefore distributed on both large and small scales.
"Galaxy clusters are ideal laboratories to understand if computer simulations of the universe reliably reproduce what we can infer about dark matter and its interplay with luminous matter," said Massimo Meneghetti of the INAF (National Institute for Astrophysics)-Observatory of Astrophysics and Space Science of Bologna in Italy, the study's lead author.
"We have done a lot of careful testing in comparing the simulations and data in this study, and our finding of the mismatch persists," Meneghetti continued. "One possible origin for this discrepancy is that we may be missing some key physics in the simulations."
Priyamvada Natarajan of Yale University in New Haven, Connecticut, one of the senior theorists on the team, added, "There's a feature of the real universe that we are simply not capturing in our current theoretical models. This could signal a gap in our current understanding of the nature of dark matter and its properties, as these exquisite data have permitted us to probe the detailed distribution of dark matter on the smallest scales."
The team's paper will appear in the Sept. 11 issue of the journal Science.
The distribution of dark matter in clusters is mapped via the bending of light, or the gravitational lensing effect, they produce. The gravity of dark matter magnifies and warps light from distant background objects, much like a funhouse mirror, producing distortions and sometimes multiple images of the same distant galaxy. The higher the concentration of dark matter in a cluster, the more dramatic its light bending.
Hubble's crisp images, coupled with spectra from the VLT, helped the team produce an accurate, high-fidelity dark-matter map. They identified dozens of multiply imaged, lensed, background galaxies. By measuring the lensing distortions, astronomers could trace out the amount and distribution of dark matter.
The three key galaxy clusters used in the analysis, MACS J1206.2-0847MACS J0416.1-2403, and Abell S1063, were part of two Hubble surveys: The Frontier Fields and the Cluster Lensing And Supernova survey with Hubble (CLASH) programs.
To the team's surprise, the Hubble images also revealed smaller-scale arcs and distorted images nested within the larger-scale lens distortions in each cluster's core, where the most massive galaxies reside.
The researchers believe that the embedded lenses are produced by the gravity of dense concentrations of dark matter associated with individual cluster galaxies. Dark matter's distribution in the inner regions of individual galaxies is known to enhance the cluster's overall lensing effect.
Follow-up spectroscopic observations added to the study by measuring the velocity of the stars orbiting inside several of the cluster galaxies. "Based on our spectroscopic study, we were able to associate the galaxies with each cluster and estimate their distances," said team member Piero Rosati of the University of Ferrara in Italy.
"The stars' speed gave us an estimate of each individual galaxy's mass, including the amount of dark matter," added team member Pietro Bergamini of the INAF-Observatory of Astrophysics and Space Science in Bologna, Italy.
The team compared the dark-matter maps with samples of simulated galaxy clusters with similar masses, located at roughly the same distances as the observed clusters. The clusters in the computer simulations did not show the same level of dark-matter concentration on the smallest scales – the scales associated with individual cluster galaxies as seen in the universe.
The team looks forward to continuing their stress-testing of the standard dark-matter model to pin down its intriguing nature.
NASA's planned Nancy Grace Roman Space Telescope will detect even more remote galaxies through gravitational lensing by massive galaxy clusters. The observations will enlarge the sample of clusters that astronomers can analyze to further test the dark-matter models.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Claire Andreoli
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
claire.andreoli@nasa.gov
Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore
410-338-4493 / 410-338-4514
dweaver@stsci.edu / villard@stsci.edu
Priyamvada Natarajan
Yale University, New Haven, Conn.
203-436-4833
priyamvada.natarajan@yale.edu
Massimo Meneghetti
INAF-Observatory of Astrophysics and Science, Bologna, Italy
massimo.meneghetti@inaf.it
Last Updated: Sept. 14, 2020
Editor: Rob Garner

Galactic Pyrotechnics From 23 Million Light Years Away | NASA

Galactic Pyrotechnics From 23 Million Light Years Away | NASA

Nasa

Galactic Pyrotechnics From 

23 Million Light Years Away

NGC 4258
A galaxy about 23 million light years away is the site of impressive, ongoing fireworks. Rather than paper, powder and fire, this galactic light show involves a giant black hole, shock waves and vast reservoirs of gas.

This galactic fireworks display is taking place in NGC 4258, also known as M106, a spiral galaxy like our own Milky Way. This galaxy is famous, however, for something that our galaxy doesn’t have – two extra spiral arms that glow in X-ray, optical and radio light. These features, or anomalous arms, are not aligned with the plane of the galaxy, but instead intersect with it.

The anomalous arms are seen in this new composite image, where X-rays from NASA’s Chandra X-ray Observatory are blue, radio data from the NSF’s Karl Jansky Very Large Array are purple, optical data from NASA’s Hubble Space Telescope are yellow and infrared data from NASA’s Spitzer Space Telescope are red.

A new study made with Spitzer shows that shock waves, similar to the sonic booms from supersonic planes, are heating large amounts of gas – equivalent to about 10 million suns. What is generating these shock waves? Researchers think that the supermassive black hole at the center of NGC 4258 is producing powerful jets of high-energy particles. These jets strike the disk of the galaxy and generate shock waves. These shock waves, in turn, heat the gas – composed mainly of hydrogen molecules – to thousands of degrees.

The Chandra X-ray image reveals huge bubbles of hot gas above and below the plane of the galaxy. These bubbles indicate that much of the gas that was originally in the disk of the galaxy has been heated and ejected into the outer regions by the jets from the black hole.

The ejection of gas from the disk by the jets has important implications for the fate of this galaxy. Researchers estimate that all of the remaining gas will be ejected within the next 300 million years – very soon on cosmic time scales – unless it is somehow replenished. Because most of the gas in the disk has already been ejected, less gas is available for new stars to form. Indeed, the researchers used Spitzer data to estimate that stars are forming in the central regions of NGC 4258, at a rate which is about ten times less than in the Milky Way galaxy.

The European Space Agency’s Herschel Space Observatory was used to confirm the estimate from Spitzer data of the low star formation rate in the central regions of NGC 4258. Herschel was also used to make an independent estimate of how much gas remains in the center of the galaxy. After allowing for the large boost in infrared emission caused by the shocks, the researchers found that the gas mass is ten times smaller than had been previously estimated.

Because NGC 4258 is relatively close to Earth, astronomers can study how this black hole is affecting its galaxy in great detail. 
Image Credit: X-ray: NASA/CXC/Caltech/P.Ogle et al; Optical: NASA/STScI; IR: NASA/JPL-Caltech; Radio: NSF/NRAO/VLA
Last Updated: Dec. 31, 2019
Editor: Yvette Smith

OSIRIS-REx Students Catch Unexpected Glimpse of Black Hole | NASA

OSIRIS-REx Students Catch Unexpected Glimpse of Black Hole | NASA

Nasa

NASA’s OSIRIS-REx Students 

Catch Unexpected Glimpse 

of Newly Discovered Black Hole

University students and researchers working on a NASA mission orbiting a near-Earth asteroid have made an unexpected detection of a phenomenon 30 thousand light years away. Last fall, the student-built Regolith X-Ray Imaging Spectrometer (REXIS) onboard NASA’s OSIRIS-REx spacecraft detected a newly flaring black hole in the constellation Columba while making observations off the limb of asteroid Bennu.
purple streaks of pixels across a portion of black sky with one bright orange dot
This image shows the X-ray outburst from the black hole MAXI J0637-043, detected by the REXIS instrument on NASA's OSIRIS-REx spacecraft. The image was constructed using data collected by the X-ray spectrometer while REXIS was making observations of the space around asteroid Bennu on Nov. 11, 2019. The outburst is visible in the center of the image, and the image is overlaid with the limb of Bennu (lower right) to illustrate REXIS’s field of view.
Credits: NASA/Goddard/University of Arizona/MIT/Harvard
REXIS, a shoebox-sized student instrument, was designed to measure the X-rays that Bennu emits in response to incoming solar radiation. X-rays are a form of electromagnetic radiation, like visible light, but with much higher energy. REXIS is a collaborative experiment led by students and researchers at MIT and Harvard, who proposed, built, and operate the instrument.
On Nov. 11, 2019, while the REXIS instrument was performing detailed science observations of Bennu, it captured X-rays radiating from a point off the asteroid’s edge. “Our initial checks showed no previously cataloged object in that position in space,” said Branden Allen, a Harvard research scientist and student supervisor who first spotted the source in the REXIS data.
Last fall, the student-built Regolith X-Ray Imaging Spectrometer (REXIS) aboard NASA’s OSIRIS-REx spacecraft detected a newly flaring black hole in the constellation Columba while making observations off the limb of asteroid Bennu.
Credits: NASA's Goddard Space Flight Center
The glowing object turned out to be a newly flaring black hole X-ray binary – discovered just a week earlier by Japan’s MAXI telescope – designated MAXI J0637-430. NASA's Neutron Star Interior Composition Explorer (NICER) telescope also identified the X-ray blast a few days later. Both MAXI and NICER operate aboard NASA's International Space Station and detected the X-ray event from low Earth orbit. REXIS, on the other hand, detected the same activity millions of miles from Earth while orbiting Bennu, the first such outburst ever detected from interplanetary space.
“Detecting this X-ray burst is a proud moment for the REXIS team. It means our instrument is performing as expected and to the level required of NASA science instruments,” said Madeline Lambert, an MIT graduate student who designed the instrument’s command sequences that serendipitously revealed the black hole.
X-ray blasts, like the one emitted from the newly discovered black hole, can only be observed from space since Earth’s protective atmosphere shields our planet from X-rays. These X-ray emissions occur when a black hole pulls in matter from a normal star that is in orbit around it. As the matter spirals onto a spinning disk surrounding the black hole, an enormous amount of energy (primarily in the form of X-rays) is released in the process.
video showing sweeps of purple pixels with one bright spot
This visualization simulates an X-ray outburst from the black hole MAXI J0637-043, detected by the REXIS instrument on NASA's OSIRIS-REx spacecraft, as it moves through REXIS’s line of sight. At first, the outburst is visibly intense, but it gradually fades as it subsides. The animation was constructed using data collected by the X-ray spectrometer while REXIS was making observations of the space around asteroid Bennu on Nov. 11, 2019.
Credits: NASA/Goddard/University of Arizona/MIT/Harvard
“We set out to train students how to build and operate space instruments,” said MIT professor Richard Binzel, instrument scientist for the REXIS student experiment. “It turns out, the greatest lesson is to always be open to discovering the unexpected.”
The main purpose of the REXIS instrument is to prepare the next generation of scientists, engineers, and project managers in the development and operations of spaceflight hardware. Nearly 100 undergraduate and graduate students have worked on the REXIS team since the mission’s inception.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
For more information on NASA’s OSIRIS-REx mission, visit:
and

By Brittany Enos
University of Arizona
Last Updated: April 13, 2020
Editor: Karl Hille

Hubble Finds Evidence of Mid-Sized Black Hole

Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole | NASA

Hubble Finds Best Evidence for Elusive Mid-Sized Black Hole | NASA

Nasa

illustration of a glowing black hole accretion disk with material spiraling into it.

Hubble Finds Best Evidence 

for Elusive Mid-Sized Black Hole

Astronomers have found the best evidence for the perpetrator of a cosmic homicide: a black hole of an elusive class known as "intermediate-mass," which betrayed its existence by tearing apart a wayward star that passed too close.
Weighing in at about 50,000 times the mass of our Sun, the black hole is smaller than the supermassive black holes (at millions or billions of solar masses) that lie at the cores of large galaxies, but larger than stellar-mass black holes formed by the collapse of a massive star.
These so-called intermediate-mass black holes (IMBHs) are a long-sought "missing link" in black hole evolution. Though there have been a few other IMBH candidates, researchers consider these new observations the strongest evidence yet for mid-sized black holes in the universe.
It took the combined power of two X-ray observatories and the keen vision of NASA's Hubble Space Telescope to nail down the cosmic beast.
Astronomers have found the best evidence for a black hole of an elusive class known as “intermediate-mass,” which betrayed its existence by tearing apart a wayward star that passed too close. This exciting discovery opens the door to the possibility of many more lurking undetected in the dark, waiting to be given away by a star passing too close.
Credits: NASA's Goddard Space Flight Center
"Intermediate-mass black holes are very elusive objects, and so it is critical to carefully consider and rule out alternative explanations for each candidate. That is what Hubble has allowed us to do for our candidate," said Dacheng Lin of the University of New Hampshire, principal investigator of the study. The results are published on March 31, 2020, in The Astrophysical Journal Letters.
The story of the discovery reads like a Sherlock Holmes story, involving the meticulous step-by-step case-building necessary to catch the culprit.
Lin and his team used Hubble to follow up on leads from NASA's Chandra X-ray Observatory and ESA's (the European Space Agency) X-ray Multi-Mirror Mission (XMM-Newton). In 2006 these satellites detected a powerful flare of X-rays, but they could not determine whether it originated from inside or outside of our galaxy. Researchers attributed it to a star being torn apart after coming too close to a gravitationally powerful compact object, like a black hole.
Surprisingly, the X-ray source, named 3XMM J215022.4−055108, was not located in a galaxy's center, where massive black holes normally would reside. This raised hopes that an IMBH was the culprit, but first another possible source of the X-ray flare had to be ruled out: a neutron star in our own Milky Way galaxy, cooling off after being heated to a very high temperature. Neutron stars are the crushed remnants of an exploded star.
black-and-white image from Hubble showing location of black hole
This Hubble Space Telescope image identified the location of an intermediate-mass black hole, weighing 50,000 times the mass of our Sun (making it much smaller than supermassive black holes found in the centers of galaxies). The black hole, named 3XMM J215022.4−055108, is indicated by the white circle. The elusive type of black hole was first identified in a burst of telltale X-rays emitted by hot gas from a star as it was captured and destroyed by the black hole. Hubble was needed to pinpoint the black hole's location in visible light. Hubble's deep, high-resolution imaging shows that the black hole resides inside a dense cluster of stars that is far beyond our Milky Way galaxy. The star cluster is in the vicinity of the galaxy at the center of the image. Much smaller-looking background galaxies appear sprinkled around the image, including a face-on spiral just above the central foreground galaxy. This photo was taken with Hubble's Advanced Camera for Surveys.
Credits: NASA, ESA and D. Lin (University of New Hampshire)
Hubble was pointed at the X-ray source to resolve its precise location. Deep, high-resolution imaging provides strong evidence that the X-rays emanated not from an isolated source in our galaxy, but instead in a distant, dense star cluster on the outskirts of another galaxy — just the type of place astronomers expected to find an IMBH. Previous Hubble research has shown that the mass of a black hole in the center of a galaxy is proportional to that host galaxy's central bulge. In other words, the more massive the galaxy, the more massive its black hole. Therefore, the star cluster that is home to 3XMM J215022.4−055108 may be the stripped-down core of a lower-mass dwarf galaxy that has been gravitationally and tidally disrupted by its close interactions with its current larger galaxy host.
IMBHs have been particularly difficult to find because they are smaller and less active than supermassive black holes; they do not have readily available sources of fuel, nor as strong a gravitational pull to draw stars and other cosmic material which would produce telltale X-ray glows. Astronomers essentially have to catch an IMBH red-handed in the act of gobbling up a star. Lin and his colleagues combed through the XMM-Newton data archive, searching hundreds of thousands of observations to find one IMBH candidate.
The X-ray glow from the shredded star allowed astronomers to estimate the black hole's mass of 50,000 solar masses. The mass of the IMBH was estimated based on both X-ray luminosity and the spectral shape. "This is much more reliable than using X-ray luminosity alone as typically done before for previous IMBH candidates," said Lin. "The reason why we can use the spectral fits to estimate the IMBH mass for our object is that its spectral evolution showed that it has been in the thermal spectral state, a state commonly seen and well understood in accreting stellar-mass black holes."
This object isn't the first to be considered a likely candidate for an intermediate-mass black hole. In 2009 Hubble teamed up with NASA's Swift observatory and ESA's XMM-Newton to identify what is interpreted as an IMBH, called HLX-1, located towards the edge of the galaxy ESO 243-49. It too is in the center of a young, massive cluster of blue stars that may be a stripped-down dwarf galaxy core. The X-rays come from a hot accretion disk around the black hole. "The main difference is that our object is tearing a star apart, providing strong evidence that it is a massive black hole, instead of a stellar-mass black hole as people often worry about for previous candidates including HLX-1," Lin said.
Finding this IMBH opens the door to the possibility of many more lurking undetected in the dark, waiting to be given away by a star passing too close. Lin plans to continue his meticulous detective work, using the methods his team has proved successful. Many questions remain to be answered. Does a supermassive black hole grow from an IMBH? How do IMBHs themselves form? Are dense star clusters their favored home?
The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.
Banner image: This illustration depicts a cosmic homicide in action. A wayward star is being shredded by the intense gravitational pull of a black hole that contains tens of thousands of solar masses. The stellar remains are forming an accretion disk around the black hole. Flares of X-ray light from the super-heated gas disk alerted astronomers to the black hole's location; otherwise it lurked unknown in the dark. The elusive object is classified as an intermediate mass black hole (IMBH), as it is much less massive than the monster black holes that dwell in the centers of galaxies. Therefore, IMBHs are mostly quiescent because they do not pull in as much material, and are hard to find. Hubble observations provide evidence that the IMBH dwells inside a dense star cluster. The cluster itself may be the stripped-down core of a dwarf galaxy. Credit: NASA, ESA and D. Player (STScI)

Claire Andreoli
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
claire.andreoli@nasa.gov
Leah Ramsay / Ray Villard
Space Telescope Science Institute, Baltimore
667-218-6439 / 410-338-4514
lramsay@stsci.edu / villard@stsci.edu
Dacheng Lin
University of New Hampshire, Durham
dacheng.lin@unh.edu
Last Updated: April 6, 2020
Editor: Rob Garner