Finding the happy medium of black holes

August 9, 2018, Chandra X-ray Center
Credit: X-ray: NASA/CXC/ICE/M.Mezcua et al.; Infrared: NASA/JPL-Caltech; Illustration: NASA/CXC/A.Hobart

This image shows data from a massive observing campaign that includes NASA's Chandra X-ray Observatory. These Chandra data have provided strong evidence for the existence of so-called intermediate-mass black holes (IMBHs). Combined with a separate study also using Chandra data, these results may allow astronomers to better understand how the very largest black holes in the early Universe formed, as described in our latest press release.

The COSMOS ("cosmic evolution survey") Legacy Survey has assembled data from some of the world's most powerful telescopes spanning the electromagnetic spectrum. This image contains Chandra data from this survey, equivalent to about 4.6 million seconds of observing time. The colors in this image represent different levels of X-ray energy detected by Chandra. Here the lowest-energy X-rays are red, the medium band is green, and the highest-energy X-rays observed by Chandra are blue. Most of the colored dots in this image are black holes. Data from the Spitzer Space Telescope are shown in grey. The inset shows an artist's impression of a growing black hole in the center of a galaxy. A disk of material surrounding the black hole and a jet of outflowing material are also depicted.

Two new separate studies using the Chandra COSMOS-Legacy survey data and other Chandra data have independently collected samples of IMBHs, an elusive category of black holes in between stellar mass black holes and the found in the central regions of massive galaxies.

One team of researchers identified 40 growing black holes in dwarf galaxies. Twelve of them are located at distances more than five billion light years from Earth and the most distant is 10.9 billion light years away, the most distant growing black hole in a dwarf galaxy ever seen. Most of these sources are likely IMBHs with masses that are about 10,000 to 100,000 times that of the Sun.

A second team found a separate, important sample of possible IMBHs in galaxies that are closer to Earth. In this sample, the most distant IMBH candidate is about 2.8 billion light years from Earth and about 90% of the IMBH candidates they discovered are no more than 1.3 billion light years away.

They detected 305 galaxies in their survey with black hole masses less than 300,000 solar masses. Observations with Chandra and with ESA's XMM-Newton of a small part of this sample show that about half of the 305 IMBH candidates are likely to be valid IMBHs. The masses for the ten sources detected with X-ray observations were determined to be between 40,000 and 300,000 times the mass of the Sun.

IMBHs may be able to explain how the very biggest black holes, the supermassive ones, were able to form so quickly after the Big Bang. One leading explanation is that supermassive black holes grow over time from smaller "seeds" containing about a hundred times the Sun's mass. Some of these seeds should merge to form IMBHs. Another explanation is that they form very quickly from the collapse of a giant cloud of gas with a mass equal to hundreds of thousands of times that of the Sun. There is yet to be a consensus among astronomers on the role IMBHs may play.

A paper describing the COSMOS-Legacy result by Mar Mezcua (Institute for Space Sciences, Spain) and colleagues was published in the August issue of the Monthly Notices of the Royal Astronomical Society and is available online. The paper by Igor Chilingarian (Harvard-Smithsonian Center for Astrophysics) on the closer IMBH sample is being published in the August 10th issue of The Astrophysical Journal and is available online.

Explore further: Image: Black hole bounty captured in the center of the Milky Way

Related Stories

Supermassive black holes are outgrowing their galaxies

February 15, 2018

The growth of the biggest black holes in the Universe is outrunning the rate of formation of stars in the galaxies they inhabit, according to two new studies using data from NASA's Chandra X-ray Observatory and other telescopes ...

Oxymoronic black hole RGG 118 provides clues to growth

August 12, 2015

Astronomers using NASA's Chandra X-ray Observatory and the 6.5-meter Clay Telescope in Chile have identified the smallest supermassive black hole ever detected in the center of a galaxy, as described in our latest press release. ...

'Red nuggets' are galactic gold for astronomers

June 21, 2018

About a decade ago, astronomers discovered a population of small, but massive galaxies called "red nuggets." A new study using NASA's Chandra X-ray Observatory indicates that black holes have squelched star formation in these ...

'Ultramassive' black holes discovered in far-off galaxies

February 20, 2018

Thanks to data collected by NASA's Chandra X-ray telescope on galaxies up to 3.5 billion light years away from Earth, an international team of astrophysicists has detected what are likely to be the most massive black holes ...

Recommended for you

Magnetized inflow accreting to center of Milky Way galaxy

August 17, 2018

Are magnetic fields an important guiding force for gas accreting to a supermassive black hole (SMBH) like the one that our Milky Way galaxy hosts? The role of magnetic fields in gas accretion is little understood, and trying ...

First science with ALMA's highest-frequency capabilities

August 17, 2018

The ALMA telescope in Chile has transformed how we see the universe, showing us otherwise invisible parts of the cosmos. This array of incredibly precise antennas studies a comparatively high-frequency sliver of radio light: ...

Another way for stellar-mass black holes to grow larger

August 17, 2018

A trio of researchers with The University of Hong Kong, Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Northwestern University in the U.S., has come up with an alternative theory to explain how some ...

Six things about Opportunity's recovery efforts

August 17, 2018

NASA's Opportunity rover has been silent since June 10, when a planet-encircling dust storm cut off solar power for the nearly-15-year-old rover. Now that scientists think the global dust storm is "decaying"—meaning more ...

Sprawling galaxy cluster found hiding in plain sight

August 16, 2018

MIT scientists have uncovered a sprawling new galaxy cluster hiding in plain sight. The cluster, which sits a mere 2.4 billion light years from Earth, is made up of hundreds of individual galaxies and surrounds an extremely ...

Hubble paints picture of the evolving universe

August 16, 2018

Astronomers using the ultraviolet vision of NASA's Hubble Space Telescope have captured one of the largest panoramic views of the fire and fury of star birth in the distant universe. The field features approximately 15,000 ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.