Featured Research

from universities, journals, and other organizations

Do black holes come in size medium?

Date:
November 29, 2013
Source:
NASA/Jet Propulsion Laboratory
Summary:
Black holes can be petite, with masses only about 10 times that of our sun -- or monstrous, boasting the equivalent in mass up to 10 billion suns. Do black holes also come in size medium? NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is busy scrutinizing a class of black holes that may fall into the proposed medium-sized category.

The magenta spots in this image show two black holes in the spiral galaxy called NGC 1313, or the Topsy Turvy galaxy. Both black holes belong to a class called ultraluminous X-ray sources, or ULXs. The magenta X-ray data come from NASA's Nuclear Spectroscopic Telescopic Array, and are overlaid on a visible image from the Digitized Sky Survey.
Credit: NASA/JPL-Caltech/IRAP

Black holes can be petite, with masses only about 10 times that of our sun -- or monstrous, boasting the equivalent in mass up to 10 billion suns. Do black holes also come in size medium? NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is busy scrutinizing a class of black holes that may fall into the proposed medium-sized category.

"Exactly how intermediate-sized black holes would form remains an open issue," said Dominic Walton of the California Institute of Technology, Pasadena. "Some theories suggest they could form in rich, dense clusters of stars through repeated mergers, but there are a lot of questions left to be answered."

The largest black holes, referred to as supermassive, dominate the hearts of galaxies. The immense gravity of these black holes drags material toward them, forcing the material to heat up and release powerful X-rays. Small black holes dot the rest of the galactic landscape. They form under the crush of collapsing, dying stars bigger than our sun.

Evidence for medium-sized black holes lying somewhere between these two extremes might come from objects called ultraluminous X-ray sources, or ULXs. These are pairs of objects in which a black hole ravenously feeds off a normal star. The feeding process is somewhat similar to what happens around supermassive black holes, but isn't as big and messy. In addition, ULXs are located throughout galaxies, not at the cores.

The bright glow of X-rays coming from ULXs is too great to be the product of typical small black holes. This and other evidence indicates the objects may be intermediate in mass, with 100 to 10,000 times the mass of our sun. Alternatively, an explanation may lie in some kind of exotic phenomenon involving extreme accretion, or "feeding," of a black hole.

NuSTAR is joining with other telescopes to take a closer look at ULXs. It's providing the first look at these objects in focused, high-energy X-rays, helping to get better estimates of their masses and other characteristics.

In a new paper from Walton and colleagues accepted for publication in the Astrophysical Journal, the astronomers report serendipitously finding a ULX that had gone largely unnoticed before. They studied the object, which lies in the Circinus spiral galaxy 13 million light-years away, not only with NuSTAR but also with the European Space Agency's XMM-Newton satellite. Archival data from NASA's Chandra, Swift and Spitzer space telescopes as well as Japan's Suzaku satellite, were also used for further studies. "We went to town on this object, looking at a range of epochs and wavelengths," said Walton.

The results indicate the black hole in question is about 100 times the mass of the sun, putting it right at the border between small and medium black holes.

In another accepted Astrophysical Journal paper, Matteo Bachetti of the Institut de Recherche en Astrophysique et Planιtologie and colleagues looked at two ULXs in NGC 1313, a spiral galaxy known as the "Topsy Turvy galaxy," also about 13 million light-years way.

These are among the best-studied ULXs known. A single viewing with NuSTAR showed that the black holes didn't fit with models of medium-size black holes. As a result, the researchers now think both ULXs harbor small, stellar-mass black holes. One of the objects is estimated to be big for its size category, at 70 to 100 solar masses.

"It's possible that these objects are ultraluminous because they are accreting material at a high rate and not because of their size," said Bachetti. "If intermediate-mass black holes are out there, they are doing a good job of hiding from us."

NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA's Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; ATK Aerospace Systems, Goleta, Calif., and with support from the Italian Space Agency (ASI) Science Data Center.

NuSTAR's mission operations center is at UC Berkeley, with the ASI providing its equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.


Story Source:

The above story is based on materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

NASA/Jet Propulsion Laboratory. "Do black holes come in size medium?." ScienceDaily. ScienceDaily, 29 November 2013. <www.sciencedaily.com/releases/2013/11/131129211131.htm>.
NASA/Jet Propulsion Laboratory. (2013, November 29). Do black holes come in size medium?. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2013/11/131129211131.htm
NASA/Jet Propulsion Laboratory. "Do black holes come in size medium?." ScienceDaily. www.sciencedaily.com/releases/2013/11/131129211131.htm (accessed April 23, 2014).

Share This



More Space & Time News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA Chief Outlines Plan for Human Mission to Mars

NASA Chief Outlines Plan for Human Mission to Mars

AFP (Apr. 22, 2014) — NASA administrator Charles Bolden, speaking at the 'Human to Mars Summit' in Washington, says that learning more about the Red Planet can help answer the 'fundamental question' of 'life beyond Earth'. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Nasa Gives You An Excuse to Post a Selfie on Earth Day

Nasa Gives You An Excuse to Post a Selfie on Earth Day

TheStreet (Apr. 22, 2014) — NASA is inviting all social media users to take a selfie of themselves alongside nature and to post it to Twitter, Facebook, Flickr, Instagram, or Google Plus with the hashtag #globalselfie. NASA's goal is to crowd-source a collection of snapshots of the earth, ground-up, that will be used to create one "unique mosaic of the Blue Marble." This image will be available to all in May. Since this is probably one of the few times posting a selfie to Twitter won't be embarrassing, we suggest you give it a go for a good cause. Video provided by TheStreet
Powered by NewsLook.com
SpaceX's Dragon Spacecraft Captured by International Space Station

SpaceX's Dragon Spacecraft Captured by International Space Station

Reuters - US Online Video (Apr. 20, 2014) — SpaceX's unmanned Dragon spacecraft makes a scheduled Easter Sunday rendezvous with the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Easter Morning Delivery for Space Station

Raw: Easter Morning Delivery for Space Station

AP (Apr. 20, 2014) — Space station astronauts got a special Easter treat: a cargo ship full of supplies. The SpaceX company's cargo ship, Dragon, spent two days chasing the International Space Station following its launch from Cape Canaveral. (April 20) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins