Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery By UCSD Astronomers Poses A Cosmic Puzzle: Can A ’Distant’ Quasar Lie Within A Nearby Galaxy?

11.01.2005


An international team of astronomers has discovered within the heart of a nearby spiral galaxy a quasar whose light spectrum indicates that it is billions of light years away. The finding poses a cosmic puzzle: How could a galaxy 300 million light years away contain a stellar object several billion light years away?


Photo of nearby spiral galaxy NCG 7319 with high red-shift quasar at arrow (below). Credit: NASA/Hubble Space Telescope




The team’s findings, which were presented today in San Diego at the January meeting of the American Astronomical Society and which will appear in the February 10 issue of the Astrophysical Journal, raise a fundamental problem for astronomers who had long assumed that the “high redshifts” in the light spectra of quasars meant these objects were among the fastest receding objects in the universe and, therefore, billions of light years away.

“Most people have wanted to argue that quasars are right at the edge of the universe,” said Geoffrey Burbidge, a professor of physics and astronomer at the University of California at San Diego’s Center for Astrophysics and Space Sciences and a member of the team. “But too many of them are being found closely associated with nearby, active galaxies for this to be accidental. If this quasar is physically associated with this galaxy, it must be close by.”


Astronomers generally estimate the distances to stellar objects by the speed with which they are receding from the earth. That recession velocity is calculated by measuring the amount the star’s light spectra is shifted to the lower frequency, or red end, of the light spectrum. This physical phenomenon, known as the Doppler Effect, can be experienced by someone standing near train tracks when the whistle or engine sounds from a moving train becomes lower in pitch, or sound frequency, as the train travels past.

Astronomers have used redshifts and the known brightness of stars as fundamental yardsticks to measure the distances to stars and galaxies. However, Burbidge said they have been unable to account for the growing number of quasi-stellar objects, or quasars—intense concentrations of energy believed to be produced by the swirling gas and dust surrounding massive black holes—with high redshifts that have been closely associated with nearby galaxies. “If it weren’t for this redshift dilemma, astronomers would have thought quasars originated from these galaxies or were fired out from them like bullets or cannon balls,” he added.

The discovery reported by the team of astronomers, which includes his spouse, E. Margaret Burbidge, another noted astronomer and professor of physics at UCSD, is especially significant because it is the most extreme example of a quasar with a very large redshift in a nearby galaxy. “No one has found a quasar with such a high redshift, with a redshift of 2.11, so close to the center of an active galaxy,” said Geoffrey Burbidge.

Margaret Burbidge, who reported the team’s finding at the meeting, said the quasar was first detected by the ROSAT X-ray satellite operated by the Max-Planck Institute for Astrophysics in Garching, Germany and found to be closely associated with the nucleus of the spiral galaxy NGC 7319. That galaxy is unusual because it lies in a group of interacting galaxies called Stephan’s Quintet.

Using a three-meter telescope operated by the University of California at Lick Observatory in the mountains above San Jose and the university’s 10-meter Keck I telescope on Mauna Kea in Hawaii, she and her team measured the redshifts of the spiral galaxy and quasar and found that the quasar appears to be interacting with the interstellar gas within the galaxy.

Because quasars and black holes are generally found within the most energetic parts of galaxies, their centers, the astronomers are further persuaded that this particular quasar resides within this spiral galaxy. Geoffrey Burbidge added that the fact that the quasar is so close to the center of this galaxy, only 8 arc seconds from the nucleus, and does not appear to be shrouded in any way by interstellar gas make it highly unlikely that the quasar lies far behind the galaxy, its light shining through the galaxy near its center by “an accident of projection.” “If this quasar is close by, its redshift cannot be due to the expansion of the universe,” he adds. “If this is the case, this discovery casts doubt on the whole idea that quasars are very far away and can be used to do cosmology.”

Other members of the team, besides Geoffrey and Margaret Burbidge, included Vesa Junkkarinen, a research physicist at UCSD; Pasquale Galianni of the University of Lecce in Italy; and Halton Arp and Stefano Zibetti of the Max-Planck Institute for Astrophysics in Garching, Germany.

Geoffrey Burbidge | EurekAlert!
Further information:
http://www.ucsd.edu

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>