The impact of double black holes and radio galaxies in the Milky Way

Jan 04, 2011
A false-color radio image of the relatively nearby radio galaxy Centaurus A, showing its giant lobes of radio emission in violet; the main galaxy and its nucleus are at the center. The inset shows a multiwavelength (including optical) image of the central galaxy. New infrared observations of distant radio galaxies have found some with multiple black holes at their nuclei. Credit: CSIRO/ATNF; ATCA;ASTRON; Parkes;MPIfR; ESO/WFI/AAO (UKST); MPIfR/ESO/APEX; NASA/CXC/CfA

(PhysOrg.com) -- Radio galaxies beam as much as one trillion solar-luminosities of radiation into space at radio wavelengths. They are therefore cosmic beacons, and the light from the most distant ones known was emitted back when the universe was only a few billions of years old (compared with its age today of about 13.7 billion years). The origin of this intense emission is thought to lie in the hot environment of a massive black hole at the galaxy's nucleus, with the radio emission being produced by electrons moving rapidly in strong magnetic fields. Astronomers seeking to better understand galaxies in general, and the context of the Milky Way's origins, want to know when and how radio galaxies formed, how they evolved, and how they impact their environments.

Luminous of course also contain stars. The relationship between the development of a radio galaxy's stars and its nuclear black hole is still very uncertain. CfA astronomers Steve Willner and Giovanni Fazio, together with nine colleagues, used the Spitzer Space Telescope and its infrared cameras to study the warm, infrared bright dust in a large sample of seventy radio galaxies whose light has been traveling towards Earth for times spanning a range of between seven and one-half to twelve billion years -- the cosmic epochs when astronomers think most galaxy maturation occurred.

The astronomers report that most of these galaxies completed the process of making the majority of their stars when the universe was only about two and one-half billion years old. They also find that differences in the infrared emission of the sample is consistent with the idea that their active nuclei are obscured by dust disks being observed at various angles. The team reaches one more notable conclusion. Four of the seventy galaxies show evidence in the images for a second supermassive black hole, suggesting that the origin of these galaxies (and perhaps the others as well during some earlier stage of development) was caused by the merger of two smaller galaxies.

In a completely separate article in the same issue of the Astrophysical Journal, CfA theoretical astronomers Yue Shen and Avi Loeb present an analysis of the spectral radiation signature of black hole binaries. If the are actually orbiting around each other rather than just being close to one another, and presuming that each has an accretion environment emitting light, the scientists show that useful diagnostic evidence of that motion will be present in the shape of the spectral lines emitted -- at least when the two black holes are orbiting fairly close together. The result, although not specifically addressing luminous radio galaxies with binary black holes, provides a new way to probe details of the black hole activity in galaxy nuclei.

Explore further: Two families of comets found around nearby star Beta Pictoris

add to favorites email to friend print save as pdf

Related Stories

Black Hole Gets Jerked Around -- Twice

Jul 21, 2010

(PhysOrg.com) -- Scientists have found evidence that a giant black hole has been jerked around twice, causing its spin axis to point in a different direction from before. This discovery, made with new data ...

X-Ray Jets

Sep 07, 2010

(PhysOrg.com) -- The supermassive black holes that lie at the centers of galaxies can spawn tremendous bipolar jets of atomic particles.

The outbursts of Fornax

Oct 01, 2010

(PhysOrg.com) -- The galaxy Fornax A, at a distance of about 74 million light-years, is one of the nearest and brightest galaxies with giant radio lobes. These huge radio lobes -- they span a million light-years ...

X-Ray Jets from Galaxies

Oct 19, 2009

(PhysOrg.com) -- Some dramatic galaxies eject gigantic, collimated jets of ionized gas millions of light-years long, powered by the massive black holes at their centers. The ionized jets are detected at radio ...

Recommended for you

New window on the early Universe

11 hours ago

Scientists at the Universities of Bonn and Cardiff see good times approaching for astrophysicists after hatching a new observational strategy to distill detailed information from galaxies at the edge of ...

Chandra's archives come to life

14 hours ago

Every year, NASA's Chandra X-ray Observatory looks at hundreds of objects throughout space to help expand our understanding of the Universe. Ultimately, these data are stored in the Chandra Data Archive, ...

New robotic telescope revolutionizes the study of stars

14 hours ago

In the last 8 months a fully robotic telescope in Tenerife has been carrying out high-precision observations of the motion of stellar surfaces. The telescope is the first in the SONG telescope network and ...

User comments : 10

Adjust slider to filter visible comments by rank

Display comments: newest first

omatumr
1.6 / 5 (7) Jan 04, 2011
It is neutron repulsion that powers galactic centers and the Sun.

1. "Attraction and repulsion of nucleons: Sources of stellar energy", J. Fusion Energy 19, 93-98 (2001).

2. "Nuclear systematics: III. The source of solar luminosity", J. Radioanal. Nucl. Chem. 252, 3-7 (2002).

3. "Neutron repulsion confirmed as energy source", J. Fusion Energy 20, 197-201 (2003).

4. "On the cosmic nuclear cycle and the similarity of nuclei and stars", J. Fusion Energy 25, 107-114 (2006). arxiv.org/pdf/nucl-th/0511051

With kind regards,
Oliver K. Manuel
geokstr
1.7 / 5 (6) Jan 04, 2011
These scientists are racists. The NAACP condemns the use of the term "black holes".

Didn't they get the memo?
omatumr
1 / 5 (6) Jan 04, 2011
This video summarizes experimental evidence that neutron powers fission, the Sun, supernovae, and galactic centers.

youtube.com/watch?v=sXNyLYSiPO0
omatumr
1 / 5 (4) Jan 04, 2011
Delete duplicate post
vidar_lund
4 / 5 (4) Jan 05, 2011
@ omatumr

I have mentioned this before but would like to repeat that there is no neutron repulsion, it is not a force of nature. Quantum mechanics simply states that two fermions as opposed to bosons cannot be in the same quantum state at the same time. To put it very bluntly, fermions don't like to be on top of each other. For this reason they resist being squeezed into a black hole singularity and end up as super compact neutron stars. The neutrons are simply incompressible like little glass marbles.
omatumr
1 / 5 (5) Jan 05, 2011
Experimentally measured mass data points for ~3,000 nuclei disagree.
gwrede
not rated yet Jan 06, 2011
A false-color radio image of the relatively nearby radio galaxy Centaurus A
This sounds like there could have been a right-color radio image.

Wouldn't it just be simpler to write "radio image"?
lomed
5 / 5 (2) Jan 07, 2011
Experimentally measured mass data points for ~3,000 nuclei disagree.
Is the neutron repulsion you speak of already included in the semi-empirical mass formula or shell model? If not, how can it produce such a large effect as you claim, since it must contribute only a small amount to the value of the nuclear binding energy (otherwise the mainstream models would not fit the data as well as they do).
frajo
5 / 5 (1) Jan 08, 2011
A false-color radio image of the relatively nearby radio galaxy Centaurus A
This sounds like there could have been a right-color radio image.

Wouldn't it just be simpler to write "radio image"?
This would be understood by laymen as a true-color image which it is not.
vidyunmaya
1 / 5 (2) Mar 01, 2011
Sub: Search Both sides of Mikyway Center as Process
A phenomena observed from -Sun-Earth end and equally a phenomena from the other edge-both activate Milkyway Processing- Search Indian Philosophy in proper perspective that has been highlighted in my projections- Remove the terminology of Black-hole and better replace with Plasma Cavity, Waveguide or Cavity Wave-guide
Vidyardhi Nanduri-Cosmology Vedas Interlinks