Tag Archives: Galaxy

Vlt Clears up dusty mystery: New Observations reveal how Stardust forms around a Supernova

The dwarf galaxy UGC 5189A, site of the supernova SN 2010jl (annotated) (Credit: ESO)
The dwarf galaxy UGC 5189A, site of the supernova SN 2010jl (annotated) (Credit: ESO)

Main Points:

A group of astronomers has been able to follow stardust being made in real time — during the aftermath of a supernova explosion. For the first time they show that these cosmic dust factories make their grains in a two-stage process, starting soon after the explosion, but continuing for years afterwards. The team used ESO’s Very Large Telescope (VLT) in northern Chile to analyze the light from the supernova SN 2010jl as it slowly faded. The new results are published online in the journal Nature on 9 July 2014.

Published in:

Nature

Study Further:

The origin of cosmic dust in galaxies is still a mystery [1]. Astronomers know that supernovae may be the primary source of dust, especially in the early universe, but it is still unclear how and where dust grains condense and grow. It is also unclear how they avoid destruction in the harsh environment of a star-forming galaxy. But now, observations using ESO’s VLT at the Paranal Observatory in northern Chile are lifting the veil for the first time. Continue reading Vlt Clears up dusty mystery: New Observations reveal how Stardust forms around a Supernova

Fast-Flowing Gas Curtails Galaxy’s Glow

NGC 5548. Bootes Penryn, California May 2008. M 250 @ f 9.3 (ag, ST-4)
NGC 5548. Bootes Penryn, California May 2008. M 250 @ f 9.3 (ag, ST-4)

Main Points:

The bright core of a spiral galaxy has unexpectedly dimmed, according to a new study by an international team of astronomers. The nucleus of galaxy NGC 5548, which contains a region of powerful X-ray light surrounding the galaxy’s central black hole, has been obscured by a fast-flowing stream of gas. Such behavior, which is rarely seen in the heart of this type of galaxy, casts new light on the poorly understood processes governing the interaction between galaxies and their central black holes. Continue reading Fast-Flowing Gas Curtails Galaxy’s Glow

Small but Significant: Astronomers Use Hubble to Study Bursts of Star Formation in the Dwarf Galaxies of the Early Universe

GOODS field containing distant dwarf galaxies forming stars at an incredible rate (annotated) (Credit:  NASA, ESA, the GOODS Team and M. Giavalisco (STScI/University of Massachusetts))
GOODS field containing distant dwarf galaxies forming stars at an incredible rate (annotated) (Credit:
NASA, ESA, the GOODS Team and M. Giavalisco (STScI/University of Massachusetts))

Main Point:

They may only be little, but they pack a star-forming punch: new observations from the NASA/ESA Hubble Space Telescope show that starbursts in dwarf galaxies played a bigger role than expected in the early history of the Universe.

Study Further:

Although galaxies across the Universe are still forming new stars, the majority of the stars were formed between two and six billion years after the Big Bang. Studying this early epoch of the Universe’s history is key in order to fully understand how these stars formed, and how galaxies have grown and evolved since. Continue reading Small but Significant: Astronomers Use Hubble to Study Bursts of Star Formation in the Dwarf Galaxies of the Early Universe

Fat or Flat: Getting Galaxies into Shape

Main Point:

Australian astronomers have discovered what makes some spiral galaxies fat and bulging while others are flat discs — and it’s all about how fast they spin.

Published in:

The Astrophysical Journal

Study Further:

The research, led by the International Centre for Radio Astronomy Research (ICRAR) in Perth, found that fast-rotating spiral galaxies are flat and thin while equally sized galaxies that rotate slowly are fatter.

The study was published today in the prestigious Astrophysical Journal and was part of “The Evolving Universe” research theme of the ARC Center of Excellence for All-sky Astrophysics (CAASTRO).

ICRAR Research Associate Professor Danail Obreschkow, from The University of Western Australia, said it is a much-debated mystery why galaxies look so different to each other.

“Some galaxies are very flat discs of stars and others are more bulging or even spherical,” he said.

Continue reading Fat or Flat: Getting Galaxies into Shape

Stream of stars in Andromeda satellite galaxy shows cosmic collision

Artist's impression of the merger between two smaller dwarf galaxies; the result was the dwarf galaxy Andromeda II. (Image Credit: N. C. Amorisco & M. Høst (Niels Bohr Institute) and ESO / Digitized Sky Survey 2)
Artist’s impression of the merger between two smaller dwarf galaxies; the result was the dwarf galaxy Andromeda II. (Image Credit: N. C. Amorisco & M. Høst (Niels Bohr Institute) and ESO / Digitized Sky Survey 2)

Main Points:

The Andromeda Galaxy is surrounded by a swarm of small satellite galaxies. Researchers from the Niels Bohr Institute, among others, have detected a stream of stars in one of the Andromeda Galaxy’s outer satellite galaxies, a dwarf galaxy called Andromeda II. The movement of the stars tells us that what we are observing is the remnant of a merger between two dwarf galaxies. Mergers between galaxies of such low mass has not been observed before. The results are published in the scientific journal Nature.

Published in:

Nature

Study Further:

The galaxies in the early universe started off small and the theory of the astronomers is that the baby galaxies gradually grew larger and more massive by constantly colliding with neighboring galaxies to form new, larger galaxies. Large, massive galaxies constantly attract smaller galaxies due to gravity and they eventually merge together and grow even larger.

Continue reading Stream of stars in Andromeda satellite galaxy shows cosmic collision

Galaxy of about 8 redshift and about 2,300 light-years width

This image shows the galaxy Abell2744 Y1, one of the most distant galaxy candidates known. (Credit: NASA / ESA / STScI / IAC.)
This image shows the galaxy Abell2744 Y1, one of the most distant galaxy candidates known. (Credit: NASA / ESA / STScI / IAC.)

Main Point:

Astronomers have reported the discovery of one of the most distant galaxies, dubbed Abell2744 Y1.

Published in:

Astronomy and Astrophysics Letters

Continue reading Galaxy of about 8 redshift and about 2,300 light-years width

Four new galaxy clusters take researchers further back in time

Main Point:

Four unknown galaxy clusters each potentially containing thousands of individual galaxies have been discovered some 10 billion light-years from Earth.

Published in:

MNRAS

Study Further:

An international team of astronomers, led by Imperial College London, used a new way of combining data from the two European Space Agency satellites, Planck and Herschel, to identify more distant galaxy clusters than has previously been possible. The researchers believe up to 2,000 further clusters could be identified using this technique, helping to build a more detailed timeline of how clusters are formed.

Continue reading Four new galaxy clusters take researchers further back in time

“Hypervelocity stars” have more speed than our galaxy

Top and side views of the Milky Way galaxy show the location of four of the new class of hypervelocity stars. These are sun-like stars that are moving at speeds of more than a million miles per hour relative to the galaxy: fast enough to escape its gravitational grasp. The general directions from which the stars have come are shown by the colored bands. (Graphic design by Julie Turner, Vanderbilt University. Top view courtesy of the National Aeronautics and Space Administration. Side view courtesy of the European Southern Observatory.)
Top and side views of the Milky Way galaxy show the location of four of the new class of hypervelocity stars. These are sun-like stars that are moving at speeds of more than a million miles per hour relative to the galaxy: fast enough to escape its gravitational grasp. The general directions from which the stars have come are shown by the colored bands. (Graphic design by Julie Turner, Vanderbilt University. Top view courtesy of the National Aeronautics and Space Administration. Side view courtesy of the European Southern Observatory.)

Main Point:

Scientists have found a new class of stars in universe, dubbed as “hypervelocity stars” moving with such a high speed that they are out of gravitational grip of the Milky Way galaxy. Continue reading “Hypervelocity stars” have more speed than our galaxy

“Super-Earths are habitable” and could have Earth-like climate

Artist rendition of super-Earth - Kepler-69c (Credit: NASA Ames/JPL-Caltech)
Artist rendition of super-Earth – Kepler-69c (Credit: NASA Ames/JPL-Caltech)

Main Points:

Scientists have reported that “super-Earths” in our galaxy have more chances of having climate similar to Earth. These chances are more than our previous expectations. Continue reading “Super-Earths are habitable” and could have Earth-like climate