Astronomers from the California Institute of Technology and the Federal Polytechnic University of Lausanne in Switzerland (EPFL) discovered the first case of a distant galaxy magnified by a quasar acting as a gravitational lens - exactly the opposite of the usual situation
Quasars, which are extremely luminous objects found in the distant universe, are considered to be the result of the activity of extremely massive black holes in the cores of galaxies. A single quasar can be brighter than an entire galaxy containing hundreds of billions of stars, making it impossible to study the host galaxies of that quasar. The significance of the discovery, the researchers say, is that it provides an innovative way to understand what is happening in the host galaxies.
"It's kind of like staring at the bright lights of a car and trying to watch the color of the fringes of the headlights," said Frédéric Corbin of EPFL, the lead researcher on the paper. "Using gravitational lenses allows us to measure the mass of the quasars' host galaxies and overcome this difficulty."
According to Einstein's theory of general relativity, if a large mass (such as a large galaxy or a galaxy cluster) is on the way in our line of sight to a distant galaxy, some of the light coming from the distant galaxy will be split. Because of this, the viewer on Earth will see two or more magnified images of the galaxy that was supposed to be hidden.
The first gravitational lens was discovered in 1979, and it produced an image of a distant quasar magnified and split by a galaxy that is between us. Hundreds of cases of gravitational lensing are known today, but until the present study, the opposite case of a background galaxy hosting a quasar amplifying a distant galaxy - had not been discovered so far.
Using gravitational lensing to measure the mass of distant galaxies as a function of their brightness was proposed in 1936 by Caltech astrophysicist Fritz Zwicky, and this technique has been used in recent years. So far it has not been applied to measuring the hosts of the quasars themselves.
To locate a cosmic lens, the astronomers searched for 'inverted' lens candidates in a vast database containing spectra of quasars imaged by the Sloan Digital Sky Scanner (SDSS). Follow-up observations of the best candidate, the quasar SDSS J0013+1523, 1.6 billion years from Earth, were made using the 10-meter telescope at the Keck Observatory on Mauna Kea in Hawaii. These observations confirmed that the quasar did indeed amplify a distant galaxy 7.5 billion light-years away.
"I'm happy that the idea really worked," said Georges Maillan, professor of physics and head of the Swiss group. "This discovery demonstrates the continued applicability of gravitational lensing as an astrophysical tool."
"Quasars are an important element in the process of the formation of galaxies and their development" said Prof. George Djorgovski, head of the group from Caltech. "Furthermore", he added, "the discovery of additional systems of this type will help us better understand the connections between quasars and the galaxies that contain them, and their joint evolution" he added.
10 תגובות
Which galaxies in the ngc catalog have gravitational priming?
deer —
Thanks for your enlightening explanation.
Again I learned something.
Michael,
When matter falls into a black hole - it moves at high speed and as a result of the friction between it and the rest of the attached matter it heats up and emits light - the intensity of illumination is very high and can carry a significant amount of the energy of the matter.
From the moment the body is engulfed in the black hole itself (not in the area where the matter was adsorbed) it cannot move any further and it "disappears" inside the black hole - from here it only came out with Hawking radiation.
This is part of the quasar's radiation and in some cases there are other types of radiation that are emitted from it and mainly concern the relativistic jet (a jet emitted from two opposite sides) - what this jet is - is still not known for sure although there are theories
In short - all the radiation emitted from a quasar originates from the vicinity of the black hole - an area where objects move quickly. Nothing is ejected from the black hole anymore.
Robitosin - Keck is not found in Mexico. It is explicitly written at the beginning of the article that Mitzpe Kek is in Hawaii. I also know this from other sources.
Please forgive me. I love beautiful articles like this, but, I don't understand astronomy the best, but I have a question:
Isn't the "Kek" observatory in Mexico???
I would love to receive comments.
!!!
"Causars, which are extremely luminous objects found in the distant universe, are considered to be the result of the activity of extremely massive black holes in the cores of galaxies."
Tam's question (maybe): How are particularly luminous objects the result of the activity of black holes? To the best of my knowledge, a black hole does not allow radiation (other than Hawking radiation) of any kind to be seen. Or did I mix here a species that is not named?
I would be happy to explain.
Ami:
What I understand from things is this:
It is very difficult to measure the mass of galaxies that contain a quasar because the illumination produced by the quasar overshadows the other stars of the galaxy.
The mass of a galaxy is usually measured by looking at the rotation speeds of individual stars around its center but this is not possible when the quasar eclipses the individual stars.
In the present case - this measurement is made possible thanks to the gravitational pull that the galaxy containing the quasar creates.
Here, too, there is a technological difficulty expressed in the words of the quoted researcher, because it is necessary to overcome the glare created by the quasar (for this reason, he likened it to looking at the edge of a car headlight).
It should be emphasized that everything that is said here is based on assumptions that some of the respondents here do not accept:
To know the same part - the method of measuring the mass of galaxies is incorrect because the laws of gravitation we use are incorrect. Beyond that - we measure total mass - including the dark mass and according to them there is no such thing.
Since the laws of gravitation are different - the gravitational acceleration is also different and therefore the method by which the mass of the current galaxy was measured is also incorrect.
In short - the entire article is significant only for those who accept the existing theories.
Do not buy religious!
I just felt like reacting like religionists react with their mafia about real estate.
Ami,
Perhaps the meaning is that the quasar's gravity is a lens for enlarging a galaxy behind it, the opposite of the classical case.
I couldn't figure out what exactly is the opposite here.
This is a normal gravitational refraction, only that in this first case there is also a quasar in the center of the galaxy that serves as a gravitational lens. First case I understood. Idush upside down, I didn't understand.