ESO: Stars forming in outflows from supermassive black holes

The latest report from ESO (European Southern Observatory):

Stars Born in Winds from Supermassive Black Holes

Artist’s impression of a galaxy forming stars within powerful outflows of material blasted out from supermassive black holes at its core. Results from ESO’s Very Large Telescope are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. [Larger images]
Observations using ESO’s Very Large Telescope have revealed stars forming within powerful outflows of material blasted out from supermassive black holes at the cores of galaxies. These are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. The results are published in the journal Nature.

New observations from ESO’s Very Large Telescope have revealed stars forming in the huge outflows in galaxies, which are driven by central supermassive black holes. This ESOcast Light takes a quick look at the important facts. Credit: ESO

A UK-led group of European astronomers used the MUSE and X-shooter instruments on the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile to study an ongoing collision between two galaxies, known collectively as IRAS F23128-5919, that lie around 600 million light-years from Earth. The group observed the colossal winds of material — or outflows — that originate near the supermassive black hole at the heart of the pair’s southern galaxy, and have found the first clear evidence that stars are being born within them [1].

Such galactic outflows are driven by the huge energy output from the active and turbulent centres of galaxies. Supermassive black holes lurk in the cores of most galaxies, and when they gobble up matter they also heat the surrounding gas and expel it from the host galaxy in powerful, dense winds [2].

Astronomers have thought for a while that conditions within these outflows could be right for star formation, but no one has seen it actually happening as it’s a very difficult observation,

comments team leader Roberto Maiolino from the University of Cambridge.

“Our results are exciting because they show unambiguously that stars are being created inside these outflows.”

The group set out to study stars in the outflow directly, as well as the gas that surrounds them. By using two of the world-leading VLT spectroscopic instruments, MUSE and X-shooter, they could carry out a very detailed study of the properties of the emitted light to determine its source.

Artist’s impression of a galaxy forming stars within powerful outflows of material blasted out from supermassive black holes at its core. Results from ESO’s Very Large Telescope are the first confirmed observations of stars forming in this kind of extreme environment. The discovery has many consequences for understanding galaxy properties and evolution. Credit: ESO/M. Kornmesser

Radiation from young stars is known to cause nearby gas clouds to glow in a particular way. The extreme sensitivity of X-shooter allowed the team to rule out other possible causes of this illumination, including gas shocks or the active nucleus of the galaxy.

The group then made an unmistakable direct detection of an infant stellar population in the outflow [3]. These stars are thought to be less than a few tens of millions of years old, and preliminary analysis suggests that they are hotter and brighter than stars formed in less extreme environments such as the galactic disc.

As further evidence, the astronomers also determined the motion and velocity of these stars. The light from most of the region’s stars indicates that they are travelling at very large velocities away from the galaxy centre — as would make sense for objects caught in a stream of fast-moving material.

Co-author Helen Russell (Institute of Astronomy, Cambridge, UK) expands:

The stars that form in the wind close to the galaxy centre might slow down and even start heading back inwards, but the stars that form further out in the flow experience less deceleration and can even fly off out of the galaxy altogether.

The discovery provides new and exciting information that could better our understanding of some astrophysics, including how certain galaxies obtain their shapes [4]; how intergalactic space becomes enriched with heavy elements [5]; and even from where unexplained cosmic infrared background radiation may arise [6].

Maiolino is excited for the future:

If star formation is really occurring in most galactic outflows, as some theories predict, then this would provide a completely new scenario for our understanding of galaxy evolution.

Notes

[1] Stars are forming in the outflows at a very rapid rate; the astronomers say that stars totalling around 30 times the mass of the Sun are being created every year. This accounts for over a quarter of the total star formation in the entire merging galaxy system.

[2] The expulsion of gas through galactic outflows leads to a gas-poor environment within the galaxy, which could be why some galaxies cease forming new stars as they age. Although these outflows are most likely to be driven by massive central black holes, it is also possible that the winds are powered by supernovae in a starburst nucleus undergoing vigorous star formation.

[3] This was achieved through the detection of signatures characteristic of young stellar populations and with a velocity pattern consistent with that expected from stars formed at high velocity in the outflow.

[4] Spiral galaxies have an obvious disc structure, with a distended bulge of stars in the centre and surrounded by a diffuse cloud of stars called a halo. Elliptical galaxies are composed mostly of these spheroidal components. Outflow stars that are ejected from the main disc could give rise to these galactic features.

[5] How the space between galaxies — the intergalactic medium — becomes enriched with heavy elements is still an open issue, but outflow stars could provide an answer. If they are jettisoned out of the galaxy and then explode as supernovae, the heavy elements they contain could be released into this medium.

[6] Cosmic-infrared background radiation, similar to the more famous cosmic microwave background, is a faint glow in the infrared part of the spectrum that appears to come from all directions in space. Its origin in the near-infrared bands, however, has never been satisfactorily ascertained. A population of outflow stars shot out into intergalactic space may contribute to this light.

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The Space Show this week – Mar.27.2017

The guests and topics of discussion on The Space Show this week:

SPECIAL TIME: 1. Monday, March 27, 2017: 9:30-11 am PDT (12:30-2:00 pm EDT, 11:30 am -1 pm CDT): We welcome back Dr. M.V. “Coyote” Smith, COL, USAF (Ret)to discuss his proposal for a US Space Corps.

2. Tuesday, March 28, 2017: 7-8:30 pm PDT, 10-11:30 pm EDT, 9-10:30 pm CDT: We welcome back Jay Wittner with Kirby Ikin and Dale Skran in honor of the NSS [National Space Society] anniversary.

3. Friday, March 31, 2016: 9:30-11 am PDT; (12:30-2 pm EDT; 11:30 am – 1 pm CDT): We welcome back Dr. Anita Sengupta of JPL for updates with the Cold Atom Lab.

4. Sunday, April 2, 2017: 12-1:30 pm DST (3-4:30 pm EDT, 2-3:30 pm CDT): I am at the Space Foundation Symposium. Please see the website newsletter for suggested Golden Oldie programs you can play.

See also:
* The Space Show on Vimeo – webinar videos
* The Space Show’s Blog – summaries of interviews.
* The Space Show Classroom Blog – tutorial programs

The Space Show is a project of the One Giant Leap Foundation.

The Space Show - David Livingston
David Livingston

Video: TMRO Orbit 10.12 – The World Space Party (Yuri’s Night)

The latest TMRO.tv program is now available in the archive: The World Space Party – Orbit 10.12 – TMRO

Cariann talks to Loretta Hidalgo Whitesides, Co-founder of Yuri’s Night, and host of Yuri’s Night L.A.

Space news topics:

* Launches from Krorou suspended by social unrest
* SpaceX to reuse CRS-8 booster this week
* China wants to reuse rockets too
* Laser Communication Relay Demonstration
* Changes on 67P observed by Rosetta
* Spacewalks on ISS

TMRO is viewer supported:

TMRO:Space is a crowd funded show. If you like this episode consider contributing to help us to continue to improve. Head over to http://www.patreon.com/tmro for information, goals and reward levels. Don’t forget to check out our SpacePod campaign as well over at http://www.patreon.com/spacepod

Videos: Four Sci-Fi short films

A selection of sci-fi short films:

** Caleb by Amanda Mesaikos & Susanne Aichele

https://youtu.be/t8BMGRWHHaE

To contend with the bullies at school, 9-year-old Caleb decides to 3D print himself. Back home there’s confusion, discord and reshuffled schedules…But maybe this is just what his family needs? With humor at its heart, CALEB is a fundamentally human story about family dynamics and the inevitability of moral dilemmas in the face of advancing technology.

** World War by Vincent Chai

https://youtu.be/C8DKUo4Kva4

A war between 2 robots fight for the fate of the world while a bomb ticks away ready to explode.

** 43,000 Feet by Campbell Hooper

When statistician John Wilkins is sucked out of a plane at 43000 feet, he calculates that he has exactly 3 minutes and 48 seconds before he hits the ground.

** The Narrow World by Brent Bonacorso

https://youtu.be/doduk_JoJsI

THE NARROW WORLD is the story of a gigantic alien that crashes to Earth and takes up residence in Los Angeles. Contrary to expectations, when the alien is neither hostile towards the tiny humans around it, nor communicative in any way, it falls on the populace to decipher what, exactly, this visitor wants and what it means for them. One man sees more to it- a message, perhaps, that may tell us less about the alien, and more about our deepest inner selves, about the mysteries of the soul.

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