Quasars & Active Galaxies
How do Supermassive Black Holes Get Super Massive?
Submitted by chandra on Mon, 2024-06-10 17:343C 58
Credit: X-ray: NASA/CXC/ICE-CSIC/A. Marino et al.; Optical: SDSS; Image Processing: NASA/CXC/SAO/J. Major
The supernova remnant 3C 58 contains a spinning neutron star, known as PSR J0205+6449, at its center. Astronomers studied this neutron star and others like it to probe the nature of matter inside these very dense objects. A new study, made using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton, reveals that the interiors of neutron stars may contain a type of ultra-dense matter not found anywhere else in the Universe.
In this image of 3C 58, low-energy X-rays are colored red, medium-energy X-rays are green, and the high-energy band of X-rays is shown in blue. The X-ray data have been combined with an optical image in yellow from the Digitized Sky Survey. The Chandra data show that the rapidly rotating neutron star (also known as a “pulsar”) at the center is surrounded by a torus of X-ray emission and a jet that extends for several light-years. The optical data shows stars in the field.
Unexpectedly Calm and Remote Galaxy Cluster Discovered
Submitted by chandra on Tue, 2023-07-18 13:52Credit: X-ray: NASA/CXC/MIT/M. Calzadilla; UV/Optical/Near-IR/IR: NASA/STScI/HST; Image processing: N. Wolk
The discovery of the most distant galaxy cluster with a specific important trait – as described in our press release – is providing insight into how these gigantic structures formed and why the universe looks like it does in the present day.
'H' is for Hot and Huge in Chandra Image
Submitted by chandra on Wed, 2023-05-03 14:43M84
Credit: X-ray: NASA/CXC/Princeton Univ/C. Bambic et al.; Optical: SDSS; Radio: NSF/NRAO/VLA/ESO; Image processing: NASA/CXC/SAO/N.Wolk
With a single letter seemingly etched in the X-ray glow around it, a giant black hole at the center of a massive elliptical galaxy is making a mark on its surroundings.
This “H”-shaped structure is found in a detailed new X-ray map of the multimillion-degree gas around the galaxy Messier 84 (M84).
As gas is captured by the gravitational force of the black hole, some of it will fall into the abyss, never to be seen again. Some of the gas, however, avoids this fate and instead gets blasted away from the black hole in the form of jets of particles. These jets can push out cavities, in the hot gas surrounding the black hole. Given the orientation of the jets to Earth and the profile of the hot gas, the cavities in M84 form what appears to resemble the letter “H.” The H-shaped structure in the gas is an example of pareidolia, which is when people see familiar shapes or patterns in random data. Pareidolia can occur in all kinds of data from clouds to rocks and astronomical images.
Centaurus A Shines in New Image from NASA's Chandra and IXPE
Submitted by chandra on Mon, 2023-05-01 11:46Centaurus A
Credit: X-ray: (IXPE): NASA/MSFC/IXPE/S. Ehlert et al.; (Chandra): NASA/CXC/SAO; Optical: ESO/WFI; Image processing: NASA/CXC/SAO/J.Schmidt
The galaxy Centaurus A (Cen A) shines bright in this image combining data from multiple observatories. In the center of this galaxy is a supermassive black hole feeding off the gas and dust encircling it, and large jets of high-energy particles and other material spewing out. The jet shown at the upper left of this image extends for about 13,000 light-years away from the black hole. Also visible is a dust lane, wrapping around the middle of the galaxy, which may have resulted from a collision with a smaller galaxy millions of years ago.
Colors in this image have been chosen to reflect the sources of data. Blue shows X-ray light captured by NASA’s Chandra X-ray Observatory, orange represents X-rays detected by NASA’s Imaging X-ray Polarimetry Explorer (IXPE) satellite, and optical light seen by the European Southern Observatory in Chile is colored white and gray.
Chandra's Indirect Glance into the Early Universe: Merging Dwarf Galaxies and their AGN
Submitted by chandra on Fri, 2023-02-17 14:49We are pleased to welcome Marko Mićić as a guest blogger. Marko led the study that is the subject of our latest press release [link to PR]. He graduated from the University of Belgrade, Serbia, with a degree in Astronomy and Astrophysics, in 2018. The same year he started a Ph.D. at the University of Alabama, and has been working under Dr. Jimmy Irwin's supervision since then. His research interests include evolution of low-mass galaxies, AGN content of low-mass galaxies, intermediate-mass black holes and gravitational lenses.
Galaxies are made up of billions of stars, interstellar gas and dust, and large amounts of dark matter. Every (or almost every) galaxy is expected to host a supermassive black hole in its center. Galaxies and their central black holes grow and evolve together predominantly through mergers; smaller objects merge to create larger ones over time. However, the earliest stages of galaxy evolution involving the mergers of the first galaxies are poorly understood. It is unclear how the first mergers affected the morphology of ancient galaxies and their star formation. We also do not know how massive the first black holes were that inhabited the first galaxies, nor how the first mergers influenced their ability to accrete – pull in – material.
It is challenging to answer these important questions because the first mergers are too distant and faint to be directly observed. One way to overcome this issue is to look for local analogs. In other words, we need to find pairs of small, dwarf galaxies that have had very quiet lives, with almost no mergers, that have only recently met and started interacting. Such galaxies have experienced little to no evolution so they are analogs of distant, ancient galaxies, and observations of their mergers would represent the local case study that illustrates the hierarchical growth of structures in the early Universe. Their central black holes are also expected not to have grown much and preserve information about primordial seeds, potentially holding the key to resolving the outstanding problem of the origin of supermassive black holes.
"X-ray Magnifying Glass" Enhances View of Distant Black Holes
Submitted by chandra on Mon, 2021-08-30 12:46Gravitationally-Lensed System MG B2016+112
Credit: Illustration: NASA/CXC/M. Weiss; X-ray (inset): NASA/CXC/SAO/D. Schwartz et al.
A new technique using NASA's Chandra X-ray Observatory has allowed astronomers to obtain an unprecedented look at a black hole system in the early Universe, as reported in our latest press release. This is providing a way for astronomers to look at faint and distant X-ray objects in more detail than had previously been possible.
Astronomers used an alignment in space that shows "gravitational lensing" of light from two objects that are nearly 12 billion light years away. An artist's illustration in the main part of this graphic shows how the paths of light from these distant objects are bent and amplified by a galaxy along the line of sight between Earth and the objects.
Telescopes Unite in Unprecedented Observations of Famous Black Hole
Submitted by chandra on Wed, 2021-04-14 06:31In April 2019, scientists released the first image of a black hole in the galaxy M87 using the Event Horizon Telescope (EHT). This supermassive black hole weighs 6.5 billion times the mass of the sun and is located at the center of M87, about 55 million light-years from Earth.
The supermassive black hole is powering jets of particles that travel at almost the speed of light, as described in our latest press release. These jets produce light spanning the entire electromagnetic spectrum, from radio waves to visible light to gamma rays.
To gain crucial insight into the black hole's properties and help interpret the EHT image, scientists coordinated observations with 19 of the world's most powerful telescopes on the ground and in space, collecting light from across the spectrum. This is the largest simultaneous observing campaign ever undertaken on a supermassive black hole with jets.
The NASA telescopes involved in this observing campaign included the Chandra X-ray Observatory, Hubble Space Telescope, Neil Gehrels Swift Observatory, the Nuclear Spectroscopic Telescope Array (NuSTAR), and the Fermi Gamma-ray Space Telescope.
From NASA’s Jet Propulsion Laboratory to the Universe's Earliest Jet propulsion Laboratory
Submitted by chandra on Mon, 2021-03-08 13:14We are happy to welcome Thomas Connor as a guest blogger today. Thomas is a NASA Postdoctoral Fellow at NASA Jet Propulsion Laboratory (JPL) in Pasadena, California and the author of a paper that is the subject of our most recent press release. He completed his undergraduate degree at Case Western Reserve University and earned his doctorate from Michigan State University. Prior to starting at JPL, Dr. Connor was a postdoctoral fellow at the Observatories of the Carnegie Institution for Science. His scientific interests include black holes in the dawn of the Universe, the evolution of galaxies in dense environments, and the structure of the Cosmic Web.
Most of the fundamental questions of astronomy relate to how the universe as we observe it was assembled. From stars and planets to nebulae and galaxies, many of the investigations of astronomy come down to crafting a coherent narrative of formation and evolution. Currently, that narrative is struggling to be built in the early universe, where supermassive black holes with masses a billion times that of the Sun are seen only a few hundred million years after the Big Bang. The challenge here is that, while we can model ways for such massive objects to form and grow, compressing that growth into such a short time scale is much more difficult. As an analogy, it is not surprising that an author can write a novel, but it would be astounding if she could do so in only one day.
Black holes grow by eating their surroundings, but, contrary to the typical depiction of these objects, they do not suck. Rather, they slowly nibble their way through an "accretion disk," an orbiting disk of gas that acts as a buffet for the black hole. As more gas makes its way inward, this disk will get hot from all of the friction of particles rubbing together, and it will start glowing like a hot coal. This bright light will act like a strong wind, pushing away further gas from replenishing the disk. Thus, the black hole's feeding is self-limiting — if it eats too fast, it won't be able to restock the buffet, and so it will have to slow down. This fundamental limit is why we are puzzled at how such massive black holes can exist so early.
The Symbiosis of Powerful Quasar Jets and Their Bright Coronas
Submitted by chandra on Tue, 2020-10-13 13:08Shifu Zhu
Shifu Zhu, a 5th-year graduate student of Astronomy & Astrophysics at Pennsylvania State University, is our guest blogger for this post. He received his B.S. in Astronomy from the University of Science and Technology of China (USTC) in 2013. He received his M.S. in Astrophysics from USTC in 2016.
“So, the answer to the nature of the X-ray emission from radio-loud quasars is simpler than we previously had thought,” I said to myself after staring for a while at our new correlations between how bright radio-loud quasars are in X-ray and ultraviolet light.
The term “quasar” was originally coined for bright radio sources that look like stars in visible-light images, i.e., quasi-stellar radio sources. Shortly after their discovery, researchers realized that quasars are supermassive black holes (with masses of millions to billions of times that of the Sun) feeding on material that is gravitationally attracted to them. Notably, despite this strong gravitational attraction, some material can also be ejected in powerful jets, narrow streams of material shooting away from the supermassive black hole in opposite directions. These jets are fueled by material in an “accretion disk” falling towards the black hole.
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