Astronomers reveal true colors of evolving galactic beasts

Astronomers reveal true colours of evolving galactic beasts
Figure 1 - Red quasar: A brief transitional phase where the young quasar is enshrouded in gas and dust. This phase is potentially associated with young jets and strong winds, which ultimately drive away the obscuring dust. Credit: S. Munro

Astronomers have identified a rare moment in the life of some of the universe's most energetic objects. Quasars were first observed 60 years ago, but their origins still remain a mystery. Now researchers at Durham University, UK, have spotted what they suggest is a "brief transition phase" in the development of these galactic giants that could shed light on how quasars and their host galaxies evolve. The new research is published in Monthly Notices of the Royal Astronomical Society.

Quasars are powered by the energy from at their centers as they feed on surrounding gases. They are thousands of times brighter than galaxies like our Milky Way and the majority are blue in color. However, a significant number are red as they are viewed through huge clouds of dust and gas that obscure them from view.

The conventional view of red quasars is that they are actually blue quasars that are angled away from our line-of-sight. Instead, the Durham team has ruled this model out and have shown that red quasars are likely to be the result of a brief, but violent, in the evolution of when the black hole ejects a large amount of energy into the surrounding clouds of dust and gas. This injection of energy blows away the dust and gas to reveal a blue quasar.

Observations using support this theory by showing that black holes at the center of red quasars produce a greater amount of radio emission than those at the center of blue quasars.

Lead author Lizelke Klindt, a Ph.D. researcher in Durham University's center for Extragalactic Astronomy, said: "How quasars develop has been the cause of significant uncertainty.

Astronomers reveal true colours of evolving galactic beasts
Figure 2 - Blue quasar: An unobscured quasar with signatures of evolved jets and less extreme winds that ultimately shut down star formation. Credit: S. Munro

"What our results suggest is that quasars undergo a brief transition phase, changing colour from red to blue, when they emerge from the deep shroud of dust and gas surrounding them.

"What we believe we are seeing is a rare but important step in the life of these galactic beasts during galaxy evolution when their are starting to shape their environments."

Astronomers reveal true colours of evolving galactic beasts
Figure 3—red vs blue quasar: Red quasar: A brief transitional phase where the nascent quasar is enshrouded in gas and dust. This phase appears to be associated with young jets and strong winds, which ultimately drive away the obscuring gas and dust. Blue quasar: An unobscured quasar with signatures of evolved jets and less extreme winds. Credit: S. Munro

The researchers studied 10,000 red and blue as they would have been seen seven to 11 billion years ago when the universe was relatively young using archival data from the Sloan Digital Sky Survey and the Very Large Array radio astronomy observatory.

They say their research could also tell us more about galaxy evolution. Co-author Professor David Alexander, Head of Astronomy, at Durham University, said: "We expect that during this transition phase the energy from the supermassive black hole will burn off the gas needed to form stars.

Astronomers reveal true colours of evolving galactic beasts
Red and blue quasars are related within an evolutionary sequence that connects dust-obscured star formation with quasar activity through gas inflow via merging galaxies and outflows from the quasar. With this model the rare red quasar population represents a brief transitional phase between the starburst and the blue quasar phase during which winds and/or jets drive away the obscuring dust, revealing an unobscured blue quasar, and ultimately shutting down the star formation to form a dormant early-type galaxy. Credit: Gemini Observatory, GMOS-South, NSF;  https://www.pxwall.com/4k-high-definition-galaxy-wallpaper/; Adapted by S. Munro

"Without the gas the galaxy cannot continue to grow, so what we are possibly seeing is the start of a quasar effectively ending the life of the galaxy by destroying the very thing it needs to survive."

The researchers say the next step in their research is to use more in-depth data to understand the finer details of this transition phase.


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More information: L Klindt et al. Fundamental differences in the radio properties of red and blue quasars: evolution strongly favoured over orientation, Monthly Notices of the Royal Astronomical Society (2019). DOI: 10.1093/mnras/stz1771
Citation: Astronomers reveal true colors of evolving galactic beasts (2019, August 7) retrieved 18 August 2019 from https://phys.org/news/2019-08-astronomers-reveal-true-evolving-galactic.html
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Aug 07, 2019
Amazing discovery which is supporting my theory.

Aug 07, 2019
Outflows are ubiquitous in astrophysics. Despite different sizes, velocity and amount of transported energy, luminosity and degree of collimation, they have obvious morphological similarities. However, what is important for us, there is the picture of the outflows from everywhere and none of inflows into somewhere. That is an obvious asymmetry. There is no universal mechanism that can explain the origin of all these jets and outflows. There is no consensus about the exact ejection mechanism. The situation is even more severe, for in many cases researchers do not understand what constitutes content of the jets. Is it atomic, molecular or ionic gas, relativistic electrons or protons, or even electron-positron plasma? In this paper we have an opportunity to build a unified model of jets and outflows in the frame of our model. https://www.acade...and_Jets

Aug 07, 2019
it is welcomed that this article clearly presents the observed evidence for modern BH theory

that whatever the hell is going on inside the BH?
only gravitational attraction is coming out past the event horizon

to power the violence of the accretion disks, jets & surrounding storm clouds

& for those who insist that stellar material is being created & expelled from inside the BHs?
if your, uhm, speculations had any bearing to the reality?

the "blue" quasars would be few in number & short-lived
while most quasars would be long-living "red's"

the opposite of what is observed by multiple sources over decades

now, unless you have your own super-duper observatory & can offer verified physical proof of evidence to the contrary?
with supporting peer-reviewed math?
your opinions have no validity

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