. 24/7 Space News .
TIME AND SPACE
Herschel Data Links Mysterious Quasar Winds to Furious Starbursts
by Staff Writers
Noordwijk, Netherlands (SPX) Dec 14, 2017


Artist's impression of radio-loud quasar in star-forming galaxy. Credit: ESA/C. Carreau

Astronomers have used ESA's Herschel Space Observatory to solve a decades-old mystery about the origin of powerful cool gas winds in the hot environs of quasars. The evidence linking these powerful winds to star formation in the quasar host galaxies may also help resolve the mystery of why the size of galaxies in the universe appears to be capped.

Since their discovery in the 1960s quasars have provided a treasure trove of questions for astronomers to answer. These energetic sources - up to 10,000 times brighter than the Milky Way - are the nuclei of distant galaxies with supermassive black holes at their heart. As gas is pulled into an accretion disc towards the black hole it heats to very high temperatures and radiates energy across the electromagnetic spectrum from radio to X-rays - in this way the signature luminosity of the quasar is born.

For five decades, astronomers have studied the spectra of quasars to uncover the origin of the electromagnetic radiation they emit and to trace the path the light has traversed to reach us.

A valuable tool in understanding this journey are the absorption lines in the quasars' radiation spectra. These lines indicate the wavelength ranges which have been absorbed as the radiation travelled from source to observer, giving clues to the material it passed through. Over time, the study of these lines has traced the composition of galaxies and gas clouds that lie between us and these distant luminous objects, but one set of absorption lines has remained unexplained.

Astronomers have observed absorption lines in many quasars that are indicative of absorption en route by cool gas with heavy metal elements like carbon, magnesium and silicon. The lines signal that the light has travelled through winds of cold gas travelling at speeds of thousands of kilometres per second within the quasars' host galaxies. Whilst knowledge that these winds exist is nothing new their origin, and why they are able to reach such impressive speeds, has remained an unknown.

Now, astronomer Peter Barthel and his PhD student Pece Podigachoski, both from the Groningen University Kapteyn Institute, together with colleagues Belinda Wilkes from the Harvard-Smithsonian Center for Astrophysics (USA) and Martin Haas at Ruhr-Universitat Bochum (Germany) have shed light on the cold winds' origins.

Using data obtained with ESA's Herschel Space Observatory the astronomers have shown, for the first time, that the strength of the metal absorption lines associated with these mysterious gas winds is directly linked to the rate of star formation within the quasar host galaxies. In finding this trend the astronomers are able to say with some confidence that prodigious star formation within the host galaxy may be the mechanism driving these mysterious and powerful winds.

"Identifying this tendency for prolific star formation to be closely related to powerful quasar winds is an exciting find for us," explains Pece Podigachoski.

"A natural explanation for this is that the winds are starburst driven and produced by supernovas - which are known to occur with great frequency during periods of extreme star formation."

This new connection not only solves one puzzle about quasars but may also contribute to unraveling an even bigger mystery: why does the size of galaxies observed in our universe appear to be capped in practice, although not in theory.

"Aside from the question of which processes are responsible for the gas winds, their net effect is a very important topic in today's astrophysics," explains Peter Barthel.

"Although theories predict that galaxies can grow very large, ultra-massive galaxies have not been observed. It appears that there is a process which acts as a brake on the formation of such galaxies: internal gas winds for example could be responsible for this so-called negative feedback."

Theory predicts that galaxies should be able to grow to masses a hundred times larger than any ever observed. The fact that there is a deficit of behemoths in the universe implies that there is a process depleting galaxies' gas reserves before they are able to reach their full potential.

There are two mechanisms likely to lead to this depletion of gas: the first is the supernova winds associated with starbursts, the second, the winds associated with the supermassive black hole at the heart of every quasar.

Although both mechanisms are likely to play a role, the evidence of correlation between cold gas winds and star formation rate found by this team suggests that in the case of quasars, star formation, which requires a steady supply of cold gas, may be the key culprit in sapping the galaxy of gas and suppressing its ability to grow the next generation of stars.

"This is an important result for quasar science, and one that relied on the unique capabilities of Herschel," explains Goran Pilbratt, Herschel Project Scientist at ESA.

"Herschel observes light in the far infrared and submillimetre enabling the detailed knowledge of the star formation rate in the galaxies observed that was needed to make this discovery."

Research Report: "Starburst-Driven Superwinds in Quasar Host Galaxies," Peter Barthel, Pece Podigachoski, Belinda Wilkes and Martin Haas, 2017 July 1, Astrophysical Journal Letters

TIME AND SPACE
Study sheds light on turbulence in astrophysical plasmas
Boston MA (SPX) Dec 04, 2017
Plasmas, gas-like collections of ions and electrons, make up an estimated 99 percent of the visible matter in the universe, including the Sun, the stars, and the gaseous medium that permeates the space in between. Most of these plasmas, including the solar wind that constantly flows out from the Sun and sweeps through the solar system, exist in a turbulent state. How this turbulence works remain ... read more

Related Links
Herschel Science Archive
Understanding Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
NASA Establishes Advisory Group for National Space Council

PARC to Partner with Commercial Space Leader to Accelerate Space R and D

Two astronauts, cosmonaut return from five-month ISS mission

Space Policy Directive calls for human expansion across the solar system

TIME AND SPACE
Russian space agency blames satellite loss on programming error

Rocket Lab makes another attempt at rocket launch in New Zealand

Nozzle Assemblies Complete for Exploration Mission-1 Solid Rocket Boosters

Rocket Lab to launch rocket from New Zealand

TIME AND SPACE
Designing future human space exploration on Hawaii's lava fields

Space program should focus on Mars, says editor of New Space

EU exempts fuel for ExoMars mission from Russian sanctions

NASA's oldest Mars rover survives another harsh winter

TIME AND SPACE
Nation 'leads world' in remote sensing technology

China plans for nuclear-powered interplanetary capacity by 2040

China plans first sea based launch by 2018

China's reusable spacecraft to be launched in 2020

TIME AND SPACE
Green Light for Continued Operations of ESA Science Missions

New business incubators will help space industry grow

mu Space becomes first Thai startup to acquire satellite license

Regulation and compliance for nontraditional space missions

TIME AND SPACE
Russia says 'satellite' could have caused radioactive pollution

Army taps Northrop Grumman for new radar risk reduction work

Better mastery of heat flow leads to next-generation thermal cloaks

Nature's toughest substances decoded

TIME AND SPACE
Life's building blocks observed in spacelike environment

Two Super-Earths around red dwarf K2-18

U of T researcher finds Earth-like conditions in little-known exoplanet - and discovers a new planet

A New Spin to Solving Mystery of Stellar Companions

TIME AND SPACE
Does New Horizons' Next Target Have a Moon?

Juno probes the depths of Jupiter's Great Red Spot

New Horizons Corrects Its Course in the Kuiper Belt

Wrapping up 2017 one year out from MU69









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.