<< Chapter < Page Chapter >> Page >

Irion, R. “A Quasar in Every Galaxy?” Sky&Telescope (July 2006): 40. Discusses how supermassive black holes powering the centers of galaxies may be more common than thought.

Kormendy, J. “Why Are There so Many Black Holes?” Astronomy (August 2016): 26. Discussion of why supermassive black holes are so common in the universe.

Kruesi, L. “Secrets of the Brightest Objects in the Universe.” Astronomy (July 2013): 24. Review of our current understanding of quasars and how they help us learn about black holes.

Miller, M., et al. “Supermassive Black Holes: Shaping their Surroundings.” Sky&Telescope (April 2005): 42. Jets from black hole disks.

Nadis, S. “Exploring the Galaxy–Black Hole Connection.” Astronomy (May 2010): 28. Overview.

Nadis, S. “Here, There, and Everywhere.” Astronomy (February 2001): 34. On Hubble observations showing how common supermassive black holes are in galaxies.

Nadis, S. “Peering inside a Monster Galaxy.” Astronomy (May 2014): 24. What X-ray observations tell us about the mechanism that powers the active galaxy M87.

Olson, S. “Black Hole Hunters.” Astronomy (May 1999): 48. Profiles four astronomers who search for “hungry” black holes at the centers of active galaxies.

Peterson, B. “Solving the Quasar Puzzle.” Sky&Telescope (September 2013): 24. A review article on how we figured out that black holes were the power source for quasars, and how we view them today.

Tucker, W., et al. “Black Hole Blowback.” Scientific American (March 2007): 42. How supermassive black holes create giant bubbles in the intergalactic medium.

Voit, G. “The Rise and Fall of Quasars.” Sky&Telescope (May 1999): 40. Good overview of how quasars fit into cosmic history.

Wanjek, C. “How Black Holes Helped Build the Universe.” Sky&Telescope (January 2007): 42. On the energy and outflow from disks around supermassive black holes; nice introduction.


Monsters in Galactic Nuclei: http://chandra.as.utexas.edu/stardate.html. An article on supermassive black holes by John Kormendy, from StarDate magazine.

Quasar Astronomy Forty Years On: http://www.astr.ua.edu/keel/agn/quasar40.html. A 2003 popular article by William Keel.

Quasars and Active Galactic Nuclei: www.astr.ua.edu/keel/agn/. An annotated gallery of images showing the wide range of activity in galaxies. There is also an introduction, a glossary, and background information. Also by William Keel.

Quasars: “The Light Fantastic”: http://hubblesite.org/newscenter/archive/releases/1996/35/background/. This brief “backgrounder” from the public information office at the HubbleSite gives a bit of the history of the discovery and understanding of quasars.


Active Galaxies: https://www.youtube.com/watch?v=Y_HgsFmwCeg. Part of the Astronomy: Observations and Theories series; half-hour introduction to quasars and related objects (27:28).

Black Hole Chaos: The Environments of the Most Supermassive Black Holes in the Universe: https://www.youtube.com/watch?v=hzSgU-3d8QY. May 2013 lecture by Dr. Belinda Wilkes and Dr. Francesca Civano of the Center for Astrophysics in the CfA Observatory Nights Lecture Series (50:14).

Questions & Answers

Currently, I'm studying in 10th grade. What should I do after my 10th so that I can get an astronomy career?
Chaya Reply
try jee exam and achieve a good score in jee advance to join in IIST(Space research institute)
okay.. thanks
this famous person was the first to recognise earthshine on the moin
Rajan Reply
Leonardo Da Vinci.....
what is string theory?
sakshi Reply
A Cosmological Theory Based On The Exsistence Of Cosmic Vibrating Strings.....
Does MIT have good astrophysics courses ?
priyanshu Reply
Probably The Best In The United States.....
But Don't Get Caught Up On Who's The Best, You Can Be The Next Noble Winning Astrophysicist.....
hmmm..........that's nice one....Adam had said.....
How did ASTRONOMY helped you understand yourself ? 🤔
Hussain Reply
why do you want to study ASTRONOMY?
Hussain Reply
It is one of the natural sciences and therefore worth exploring. You are a part of the universe and it is a part of you. The sky is my classroom. (student of cosmology, Oxford Uni)
because everything in the space is just beautiful...interesting and worth studying and exploring...
I have been studying astrophysics an love it
I love to learn what makes up our lives an heavens an how it works there us so much more out there than books an our veiw of thw heavens can reveal
How did ASTRONOMY helped you understand yourself ?
Because it proves the impossibles and the limitless.
It helped me realize that there are like countless possibilities in life and get all through it.
It honestly showed me to view the world in a balanced way. Because space beautiful and calm yet violent, and so is the world, and we should still help, but there will always be violent people much like violent astrophysical jets.
Does anyone know where can I study astronomy in Spain? My budget is too low for traveling out there...
Valerian Reply
How long the duration was when the laws of physics became active after the big bang?And why the time is called plank's time?
Mostak Reply
how many galaxies in universe?
Shaikh Reply
10 to the power 11
if u can count all the sands on the beaches and on the deserts then u will know how much it will be.......some said more than 1,000,000,000 galaxies are there in our universe...
it's ok bro
I hope you will become a member of nasa
just new in this area, from art background not science
what's ur name wwe
The Observable Universe Contains Between 200 Billion To 2 Trillion Galaxies.....
are u sure?
It actually hasn't been proven, people have just made estimations.
the thing is u can't count,maybe the our number system will collapse there...who knows?
What's the exact time when the laws of physics became active after the big bang ?
Actually we still don't know the exact number of galaxies in the universe, since the universe is bigger than we can imagine and it is still expanding even bigger today than yesterday
we didn't actually find the exact number but may be it is around 100 billion
why this universe is expanding?
Science Does Not Concern It Self With Why Questions, Science Is Geared For How And What Questions.....
Why Questions Form And Endless Loop.....
According to the universal law of cause and effect .any phenomenon that occur in this universe should have any reason , nothing happen without any reason.
Can you tell me the expanding speed of this universe.
yes that would be a great question to have answered what is the expanding speed of the universe?
Remember that most of what you can see is light years away. We're looking back in time, we can never know the current nature of our observations, only glimpse the galaxies and stars as they once were. Strange but true, and a little sad.
Correct, That's Why Telescopes Are Like Time Machines, You See The Past.....
really telescope can see the past?....i meant everything is in its place, though it rotates or revolve or whatever it is.......but how can this telescope can see the past.....can we see how our Universe was created,how it formed out of it? thats my question to all of you guys can you plz tell me.
Because We Dont See Any Object In Space As It Is, We See It As It Was..... Hope This Clears That Up For You.....
And One Day We Might Have A Telescope That Will Show Us The Big Bang.....
ok....... that will be nice one
ok....... that will be nice one
Travel at light speed in a spaceship at 186,000 miles every SECOND. At this speed it will take you 100,000 years just to cross our Milky Way galaxy, which is just a dot in the sky. Next stop, the Andromeda galaxy, after 2.5 million years, still in the Local Group, Virgo Supercluster, still a dot.
Pretty Much.....
there are nearly 200 million I suppose.
hi i need a telescope would you help mee
Nauman Reply
i can only advice you to go to some museum
wher is it?
but before that.......... i wanna know where are you from and from which state...and if you are nearer to that of the museum or will be able to go then.,.. i donot have any more words.
What Do Plan To Observe?
sorry . i am from asia
Check on amazon.Celeston telescopes are good for beginners.
can yoy introduce your self
can you
Asia...? from which country you belong into ...,,is it India or where?
Do You Want A Telescope With ALot Of Maintenance Or Zero Maintenance?
with alot offf
Any second hand online stores in your area? great for unused Christmas gifts etc..
So You Want A Newtonian Reflector?
hey guys I wanna ask you all that will it be safe or helpful to communicate with an intelligent civilization like are we safe ?
Is the Orion Sky Quest XT6 a good Dobsonian?
Look for a Sky Watcher 130BKS, it has an upgraded dual speed 2" focuser. You can use 1.25" or 2" eyepieces with it and it is quite easy to pollinate using a simple visual collimating eyepiece. This scope is great and ready for prime focus astrophotography if you choose to go that route.
Sorry, spell check error. Pollinate should be collimate. lol
Dobsonians Require A Lot Of Maintenance, If You Don't Mind Cleaning And Collimating On A Regular Basis, Then Go Ahead A Dobsonian Puts Up Excellent Views Especially For Deep Space Objects..... Now If You Don't Want Constant Maintenance Then A Schmidt Cassegrain Might Be A Better Fit For You.....
So what i would put for that answer ?
Abdulla Reply
The largest observatory complex in the world is on Mauna Kea, the tallest mountain on Earth. Whatare some factors astronomers consider when selecting an observatory site? Don’t forget practical ones.Should astronomers, for example, consider building an observatory on Denali (Mount McKinley) or MountEverest?
Abdulla Reply
i need help on the the second part
Should astronomers for example considered building an observatory on Denali (Mount Mckinley) or MountEverest ?
I would take into consideration. climate weather pattern.
also, could an establishment be built and be able to sustain years of being beaten by the weather?
so far Mount Everest to my understanding is a difficult mountain
it is because of light pollution in the cities that the observatories are situated in extremely remote areas.
Everest ist the tallest mountain
how far us milky way galaxy?
ShowsSpy Reply
oh man
We are part of the Milky Way Galaxy. We are within it, so it's not really away from us. Our galaxy is 100,000 light years in diameter. The nearest big galaxy is Andromeda, around 2 million lightyears away.
its 200,000 light years
Where is Rice University located?
Amanda Reply
it is in your vagina
that couldn't be any more wrong 😂😂
what even is this conversation😂😂!?
Show Some Class.....
Houston, Texas.....
what is the first step to take as far as getting into the field of astronomy?
john Reply
probably by being type 1or2 civilization...launching more telescopes into space...and stepping on mars. probably.
John, the first step is to want to focus a large part of your life studying, researching and investigating the universe... Including the planet we know the most about. Do well in math, physics, and chemistry, and attend a college that either owns astronomical equipment or facilities and has courses.

Get the best Astronomy course in your pocket!

Source:  OpenStax, Astronomy. OpenStax CNX. Apr 12, 2017 Download for free at http://cnx.org/content/col11992/1.13
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Astronomy' conversation and receive update notifications?