Black Holes Raze Thousands of Stars to Fuel Growth

Astronomers have found evidence for the destruction of thousands of stars in multiple galaxies, using NASA's Chandra X-ray Observatory. Growing black holes within dense stellar clusters are thought to be responsible for this large-scale devastation. This process could account for "intermediate mass black holes" through the runaway growth of stellar-mass black holes. The new study involved the observations of over a hundred galaxies with Chandra.

Credit: X-ray: NASA/CXC/Washington State Univ./V. Baldassare et al.; Optical: NASA/ESA/STScI

First glimpse of lone black hole delights astronomers

The invisible cosmic tourist could carry clues about supernova explosions.

Black holes distort the light coming from objects around them. Credit: NASA GSFC, ESA/Gaia/DPAC

ESO telescope uncovers closest pair of supermassive black holes yet

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have revealed the closest pair of supermassive black holes to Earth ever observed. The two objects also have a much smaller separation than any other previously spotted pair of supermassive black holes and will eventually merge into one giant black hole.

This image shows close-up (left) and wide (right) views of the two bright galactic nuclei, each housing a supermassive black hole, in NGC 7727, a galaxy located 89 million light-years away from Earth in the constellation Aquarius. Each nucleus consists of a dense group of stars with a supermassive black hole at its centre. The two black holes are on a collision course and form the closest pair of supermassive black holes found to date. It is also the pair with the smallest separation between two supermassive black holes found to date — observed to be just 1600 light-years apart in the sky. The image on the left was taken with the MUSE instrument on ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile while the one on the right was taken with ESO's VLT Survey Telescope. Credit: ESO/Voggel et al.; ESO/VST ATLAS team. Acknowledgement: Durham University/CASU/WFAU

Black Holes Must Have Singularities, Says Einstein’s Relativity

Unless you can make a force that travels faster than the speed of light, a singularity is inevitable.

Inside a black hole, the spacetime curvature is so large that light cannot escape, nor can particles, under any circumstances. A singularity, based on our current laws of physics, must be an inevitability. Image credit: Pixabay user JohnsonMartin. 

A binary black hole at the heart of the nearest quasar Markarian 231

Schematic diagram for a BBH–disk (BBH = Binary Black Hole) accretion system. The BBH is assumed to be on circular orbits. The BBH is surrounded by a circumbinary disk, connecting with the mini-disk around each component of the BBH by streams. In between the circumbinary disk and the inner mini-disks, a gap or hole is opened by the secondary SMBH (= SuperMassive Black Hole)

Discovering Dust-Obscured Active Galaxies as They Grow

How did galaxies form and evolve during the 13.8-billion-year history of the universe? This question has been the subject of intense observational and theoretical investigation. Recent studies have revealed that almost all massive galaxies harbor a supermassive black hole whose mass reaches up to a hundred thousand or even a billion times the mass of the sun, and their masses are tightly correlated with those of their host galaxies. This correlation suggests that supermassive black holes and their host galaxies have evolved together, closely interacting as they grow.

The number density of DOGs (Dust Obscured Galaxies) as a function of infrared luminosity. Data represented by the red star is the HSC result (Hyper Suprime-Cam, or HSC, is a new wide-field camera mounted at the prime focus of the Subaru Telescope). The research team found that (i) their infrared luminosity exceeds 10 trillion suns, and (ii) their number density is about 300 per cubic gigaparsecs (1 gigaparsec is about 3×10²⁵ meter)

Bumpy Black Hole X-Rays May Push the Limits of Einstein’s Relativity

In the century since Albert Einstein proposed his theory of general relativity physicists have put it through the wringer with extensive experimental tests—and it has withstood them all. But these experiments were conducted in environments of relatively weak gravity. Scientists have thus been left to wonder how well the theory describes the universe under more extreme conditions, like those found in the regions around black holes. To that end a new study suggests a means of testing the limits of the theory: Researchers have determined that if general relativity does break down near black holes, the effects may be detectable in x-rays blazing off the infalling matter. The study was published in Physical Review D on July 22.

Astronomers find ‘teeny supermassive black hole’

In a dwarf, disc galaxy 340 million light years away, astronomers have found the smallest black hole ever observed in the center of a galaxy.

An artist’s conception shows a black hole surrounded by a disk of hot gas, and a large doughnut or torus of cooler gas and dust. The light blue ring on the back of the torus is due to the fluorescence of iron atoms excited by X-rays from the hot gas disk

Hubble Finds Evidence of Galaxy Star Birth Regulated by Black-Hole Fountain

Astronomers have uncovered a unique process for how the universe’s largest elliptical galaxies continue making stars long after their peak years of star birth. NASA’s Hubble Space Telescope’s exquisite high resolution and ultraviolet-light sensitivity allowed the astronomers to see brilliant knots of hot, blue stars forming along the jets of active black holes found in the centers of giant elliptical galaxies.

This artist’s rendering shows a central black hole interacting with gas in the galaxy’s halo to create a self-regulating cycle. In this cycle, jets shooting out of the galaxy’s center heat a halo of surrounding gas, controlling the rate at which the gas cools and falls into the galaxy to form stars

Super Star takes on Black Holes in Jet Contest

A super-dense star formed in the aftermath of a supernova explosion is shooting out powerful jets of material into space, research suggests.

An artist’s impression of the binary star system PSR J1023+0038. The extremely dense, rapidly-spinning neutron star, just 10-15 km in size, is in a close orbit with a more normal companion star. The strong gravity of the neutron star pulls gas from its companion, which spirals in towards the neutron star, forming a disk. Some fraction of that gas gets accelerated outwards in energetic, oppositely-directed jets, which give off the radio waves that can be seen by Earth’s radio telescopes

Neutron Stars Strike Back at Black Holes in Jet Contest

Some neutron stars may rival black holes in their ability to accelerate powerful jets of material to nearly the speed of light, astronomers using the Karl G. Jansky Very Large Array (VLA) have discovered.

Artist’s impression of material flowing from a companion star onto a neutron star. The material forms an accretion disk around the neutron star and produces a superfast jet of ejected material. The material closest to the neutron star is so hot that it glows in X-rays, while the jet is most prominent at radio wavelengths. A similar mechanism is at work with black holes

Record massive black holes discovered lurking in monster galaxies

University of California, Berkeley, astronomers have discovered the largest black holes to date - two monsters with masses equivalent to 10 billion suns that are threatening to consume anything, even light, within a region five times the size of our solar system.

An artist’s concept of stars moving in the central regions of a giant elliptical galaxy that harbors a supermassive black hole

Mind the Binaries

Mergers of binary black holes from dense star clusters may be promising sources of gravitational waves.

Black holes merging seen edge-on. Source: black-holes.org

Distant Black Hole Wave Twists Like Giant Whip

Fast-moving magnetic waves emanating from a distant supermassive black hole undulate like a whip whose handle is being shaken by a giant hand, according to a new study using data from the National Radio Astronomy Observatory’s Very Long Baseline Array. Scientists used this instrument to explore the galaxy/black hole system known as BL Lacertae (BL Lac) in high resolution.

This cartoon shows how magnetic waves, called Alfven S-waves, propagate outward from the base of black hole jets. Source: NASA

Treasure hunting in archive data reveals clues about black holes’ diet

 

Andrea Merloni and members of his team from the Max-Planck Institute for Extraterrestrial Physics (MPE) in Garching, near Munich, were exploring the huge archive of the Sloan Digital Sky Survey (SDSS) in preparation for a future X-ray satellite mission. The SDSS has been observing a large fraction of the night sky with its optical telescope; in addition, spectra have been taken of distant galaxies and black holes. For a variety of reasons, some objects got the spectra taken more than once. And when the team was looking at one of the objects with multiple spectra, they were struck by an extraordinary change in one of the objects under study, with the catalogue number SDSS J0159+0033.

A snapshot image from a computer simulation of a star disrupted by a supermassive black hole. The red-orange plumes show the debris of the star after its passage near the black hole (located close to the bottom left corner of the image). About half of the disrupted star moves in elliptical orbits around the black hole and forms an accretion disc which eventually shines brightly in optical and X-rays. Source: Max-Planck-Gesellschaft

A black hole under the gravitational lens

Sky chart (left) of the enlargement by factors of up to 20, caused by a star in the foreground galaxy. The gamma ray region of the blazar behind it moves across this pattern (white cross). The image this creates (right) is amplified to different degrees. The splitting into several images which can also be seen on the right cannot be resolved with gamma ray telescopes. At the top left of the image on the right is the blazar as it would appear without the lens effect. 

NuSTAR Stares Deep into Hidden Lairs of Black Holes

Some of the “biggest and baddest” black holes around are buried under thick blankets of gas and dust. These monsters in the middle of galaxies are actively devouring material, but their hidden nature makes observing them a challenge.

Source: Caltech

Black Hole Too Big for its Breeches

A supermassive black hole in the early universe is at least 10 times too heavy for its host galaxy, raising questions about galaxy and black hole coevolution.

CID-947 is a supermassive black hole that’s visible across the observable universe because it’s actively gobbling down gas and spitting out radiation. It’s a classic quasar in every way except one: its supermassive black hole is too heavy for its galaxy.

Over the past decade, astronomers have discovered that supermassive black holes have a scaling relationship with their host galaxies: the more massive the black hole, the more massive the galaxy. On average, a supermassive black hole has a mass 1/100 to 1/1,000 times that of its host galaxy. Seemingly consistent relationships like this one have led astronomers to suspect that a black hole’s growth and its host galaxy’s growth are intertwined.

But CID-947 doesn’t lie anywhere near this relation. At 2 billion years after the Big Bang, this quasar only weighs eight times less than its host galaxy.

Unexpectedly Little Black-hole Monsters Rapidly Suck up Surrounding Matter

Schematic view of ULXs (looking from upper side) and SS 433 (looking from left side). Strong X-rays are emitted from the inner region of the supercritical accretion disk. Powerful winds are launched from the disk, which eventually emit spectral lines of helium ions and hydrogen atoms. Source: Subaru Telescope

“Mailbox spammed by a blackhole”

NASA’s Swift satellite detected a rising tide of high-energy X-rays from the constellation Cygnus on June 15, just before 2:32 p.m. EDT. About 10 minutes later, the Japanese experiment on the International Space Station called the Monitor of All-sky X-ray Image (MAXI) also picked up the flare.

Source: NASA