Peering into a gateway opened 50 years ago

Mar 17, 2013 by Amina Khan
An X-ray image of the quasar PKS 1127-145, located about 10 billion light-years from Earth. Credit: NASA.

Saturday marked the 50th anniversary of the discovery of the quasar - an extremely bright object powered by matter falling into a super-massive black hole lying in the heart of a galaxy.

First found in 1963, these strange sources of initially stumped astronomers: They shone as sharply and intensely as , but they appeared to be moving away from Earth far too fast to be in our own Milky Way. Scientists called them quasi-stellar radio sources - or quasars for short.

Eventually, astronomers realized that only a black hole had enough power to produce such bright light from such mind-boggling distances. Compared to faint galaxies, these cosmic beacons offered a tantalizing glimpse into the very - and thus, a window into its evolution.

California Institute of Technology astronomer Maarten Schmidt discovered the first known quasar, 3C273, on March 16, 1963. He spoke with the about his groundbreaking discovery.

Question: What was it like to discover such a strange new phenomenon?

Answer: It was really exciting. These quasars - they were so unexpected. It was, I must say, the highlight of my own science in my career.

Q: A "bright spot," you might say.

A: Yup.

Q: How did you come across that first quasar, 3C273?

A: The radio astronomers after were producing catalogs of radio sources that were quite reliable. Usually these radio sources were identified with galaxies. 3C273 was one of the first ones where the identification was not with a galaxy. We believed it originally to be a star.

Q: So you measured the object's , which tells you how much the light from an object is getting stretched out as the object travels away from you. What did this show?

A: Redshifts are just a measure of distance in the universe. High redshifts mean large distances.

If the object were a star, it would have to be in our own galaxy, of course. And the stars in our galaxy have a velocity never larger than 600 kilometers per second - that would be a redshift of 0.2 percent. If a star has a velocity larger than that, it would escape the galaxy. Anything that has a redshift of even 1 percent has to be outside the galaxy.

But when I took a spectrum in 1962 and also in 1963, it turned out that it was redshifted by 16 percent. That corresponds to a velocity off 47,000 kilometers per second.

Q: That's a lot faster.

A: Yes! So it really stood out, and it could not be ignored.

Q: If this strange object was sitting billions of light-years away, how could you see it?

A: It was 40 times more luminous than an entire galaxy of 100 billion stars. It was an exceptional object.

Q: Did you realize it was in the center of another galaxy?

A: No. These quasars occur in the center of , but are so incredibly bright that they masked the whole galaxy. That took a long time to establish.

Q: Were you surprised by your own conclusions?

A: Absolutely. My wife still tells me I was pacing the floor in the evening and couldn't stop.

At times we thought we were just barking up the wrong tree, but you look at the observations again, and what other explanation could we give?

Q: How did the discovery of quasars change the way we viewed the universe?

A: It allowed us to go back easily in time. For instance, after a number of years I concluded that the number of quasars in the universe had been much larger in the past than it is now, by a factor of 100. And it was the first case where we saw the universe was changing.

This is the evolution of the universe, as it were.

Q: Fifty years later, do we see the universe differently because of quasars?

A: The universe before used to be a rather quiet place - at least, that's what the astronomers thought. And it turned out that all sorts of things are happening.

As some people later on said, it's a violent .

Explore further: Quest for extraterrestrial life not over, experts say

More information: This interview has been edited for clarity.

4.6 /5 (7 votes)
add to favorites email to friend print save as pdf

Related Stories

Galaxy 'hunting' made easy

Sep 14, 2007

Astronomers using ESO's Very Large Telescope have discovered in a single pass about a dozen otherwise invisible galaxies halfway across the Universe. The discovery, based on a technique that exploits a first-class ...

Astronomers discover new way to measure Universe

Sep 27, 2011

(PhysOrg.com) -- Astronomers at Copenhagen's Niels Bohr Institute have found a new way to measure distances. This may not sound like much, but working out how far away something is, is one of the toughest ...

Extremely rare triple quasar found

Mar 12, 2013

(Phys.org) —For only the second time in history, a team of scientists—including Carnegie's Michele Fumagalli—have discovered an extremely rare triple quasar system. Their work is published by Monthly No ...

Merging galaxies create a binary quasar (w/ Video)

Feb 03, 2010

Astronomers have found the first clear evidence of a binary quasar within a pair of actively merging galaxies. Quasars are the extremely bright centers of galaxies surrounding super-massive black holes, and ...

Recommended for you

Quest for extraterrestrial life not over, experts say

Apr 18, 2014

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

Continents may be a key feature of Super-Earths

Apr 18, 2014

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Exoplanets soon to gleam in the eye of NESSI

Apr 18, 2014

(Phys.org) —The New Mexico Exoplanet Spectroscopic Survey Instrument (NESSI) will soon get its first "taste" of exoplanets, helping astronomers decipher their chemical composition. Exoplanets are planets ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

jsdarkdestruction
5 / 5 (2) Mar 17, 2013
I must say quasars are what really got my interest in astronomy raging. i had a few old books from the 70's before they knew what they actually were that fascinated me when i was young. then going online and finding out what progress had been made...i was hooked.
Egleton
1 / 5 (2) Mar 18, 2013
Has the red shift ruler been calibrated? What can affect it's calibration?
It has been suggested by Marmon that light loses energy at right angles to it's path in the 1200 meter wavelength when it encounters protium.
If this were the case then the amount of energy seen would be orders of magnitude lower than calculated, because the object would be nearer.
The question is "Is the red shift relied on as a matter of faith and groupthink prevents the questioning of it?"
Fleetfoot
5 / 5 (3) Mar 18, 2013
Has the red shift ruler been calibrated? What can affect it's calibration?


Modifications to the base measurements can have an influence, see the recent report in Phys.org on a new measurement of the distance to the LMC for example.

http://phys.org/n...axy.html

It has been suggested by Marmon that light loses energy ...


Tired light was suggested by Zwicky in 1929.

The question is "Is the red shift relied on as a matter of faith and groupthink prevents the questioning of it?"


Everything is questioned. Here is the answer:

http://arxiv.org/.../0104382

More news stories

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Cosmologists weigh cosmic filaments and voids

(Phys.org) —Cosmologists have established that much of the stuff of the universe is made of dark matter, a mysterious, invisible substance that can't be directly detected but which exerts a gravitational ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.