Astronomers see a quiet galaxy become active for the first time
Using a number of space- and ground-based telescopes, astronomers have for the first time seen in real time what had previously been a very inactive and quiet galaxy become active and energetic, suggesting a major event at the galaxy’s center had taken place to change its behavior.
From the abstract of the paper [pdf]:
We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 10 6 M ⊙ AGN [a one million solar mass black hole] that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGN observed in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour.
As noted in the press release:
Some phenomena, like supernova explosions or tidal disruption events — when a star gets too close to a black hole and is torn apart — can make galaxies suddenly light up. But these brightness variations typically last only a few dozen or, at most, a few hundreds of days. SDSS1335+0728 is still growing brighter today, more than four years after it was first seen to ‘switch on’. Moreover, the variations detected in the galaxy, which is located 300 million light-years away in the constellation Virgo, are unlike any seen before.
If the central black hole is switching from being quiet to active, this galaxy is providing astronomers critical information for understanding such changes. This is particularly important to us here in the Milky Way, which has a very inactive central supermassive black hole weighing about 4 million solar masses. It would be very useful to understand what would cause it to become active, especially because such an event might even have an impact — possibly negative — throughout our entire galaxy.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Using a number of space- and ground-based telescopes, astronomers have for the first time seen in real time what had previously been a very inactive and quiet galaxy become active and energetic, suggesting a major event at the galaxy’s center had taken place to change its behavior.
From the abstract of the paper [pdf]:
We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 10 6 M ⊙ AGN [a one million solar mass black hole] that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGN observed in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour.
As noted in the press release:
Some phenomena, like supernova explosions or tidal disruption events — when a star gets too close to a black hole and is torn apart — can make galaxies suddenly light up. But these brightness variations typically last only a few dozen or, at most, a few hundreds of days. SDSS1335+0728 is still growing brighter today, more than four years after it was first seen to ‘switch on’. Moreover, the variations detected in the galaxy, which is located 300 million light-years away in the constellation Virgo, are unlike any seen before.
If the central black hole is switching from being quiet to active, this galaxy is providing astronomers critical information for understanding such changes. This is particularly important to us here in the Milky Way, which has a very inactive central supermassive black hole weighing about 4 million solar masses. It would be very useful to understand what would cause it to become active, especially because such an event might even have an impact — possibly negative — throughout our entire galaxy.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
What exactly is it actively doing? What is the difference between an an active galaxy and a quiet one? This article doesn’t illuminate much.
Hawkpilot: An active galactic nucleus (AGN) or blazar emits a lot of energy from its central supermassive black hole in wavelengths like X-rays and gamma rays. The supermassive black hole in a quiet galaxy like the Milky Way emits relatively little by comparison.
Hawkpilot-
– what Mr. Z. said..
Active Galaxies and Quasars
https://youtu.be/h9WW–hmcYg
(12:38)
Robert, great link, thanks for posting it. A few minor grammatical nits in your commentary. You used the word ‘quite’ when you likely intended to use the word ‘quiet’, and ‘massives’ instead of ‘masses’.
You can throw this comment into the black hole.
Wamphyr: Typos fixed. Thank you!