Massive Stars Near the Galactic Center

August 28, 2009,
A false-color infrared image of the Central Molecular Zone in our Milky Way galaxy. Astronomers have used infrared spectroscopy to confirm for the first time the presence of very young, massive stars in this unusual region. Credit: NASA/JPL-Caltech

The Central Molecular Zone (CMZ) of our galaxy is a giant complex of molecular gas and dust situated in the innermost 700 light-years of the Milky Way. Although the galaxy is over 100,000 light-years in size, nearly 10% of all of its molecular gas lies in the CMZ. Astronomers know that regions of dense gas and dust tend to produce new stars as the material coalesces and heats up under the influence of gravity.

There should therefore be abundant star formation going on in the CMZ, and indeed the CMZ is the source of about 5%-10% of the galaxy's infrared and because of its star formation activity. Evidence has mounting that conditions for star formation in the CMZ are significantly different from those elsewhere -- the gas pressures and temperatures are higher than elsewhere, for example.

Furthermore, the presence of strong magnetic fields, tidal shear, and turbulence challenges the standard paradigm of slow gravitational collapse of molecular cloud cores. Astronomers piecing together the complex puzzle of star formation look to the CMZ region as a testbed for their understanding of .

There is plenty of indirect evidence for massive stars in the CMZ; the influence can be seen across the spectrum, from the radio to the X-ray. But there is a huge amount of dust between us and the CMZ -- optical light, for example, is extinguished by a factor of about one trillion -- and so it has been hard to identify positively any young, new or protostars there. Spectroscopic observations in the infrared offer a key way to do this because they are not as easily confused as methods that rely on stellar colors (evolved stars can appear like young stars in their colors when they are heavily dust attenuated). These young stars are likely to be the ones to reveal the most about any special birth conditions or processes at work there.

SAO astronomer Howard Smith is a member of a team of ten scientists who have used the Spitzer Space Telescope to probe the galactic center, the CMZ, and their stars.

Writing in the latest issue of The Astrophysical Journal Letters, the team's latest paper reports the first conclusive spectroscopic evidence for massive young stars in the CMZ. They identify three such objects from the presence of warm molecular gas features in their photospheres (or envelopes), features that are familiar from studies of young stars much closer to earth. While confirming the competing roles of various processes in the CMZ still requires a larger sample of young stars and additional modeling, the new results are a key step in the goal of better understanding the wide range of environments that can give birth to massive young stars.

Provided by Harvard-Smithsonian Center for Astrophysics (news : web)

Explore further: Coronet: A Star Formation Neighbor

Related Stories

Coronet: A Star Formation Neighbor

September 13, 2007

While perhaps not quite as well known as its star formation cousin of Orion, the Corona Australis region (containing, at its heart, the Coronet Cluster) is one of the nearest and most active regions of ongoing star formation.

Turbulence May Promote the Birth of Massive Stars

February 23, 2009

( -- On long, dark winter nights, the constellation of Orion the Hunter dominates the sky. Within the Hunter's sword, the Orion Nebula swaddles a cluster of newborn stars called the Trapezium. These stars are ...

Spitzer Unveils Infant Stars in the Christmas Tree Cluster

December 22, 2005

Astronomers using NASA's Spitzer Space Telescope have given the world a spectacular new picture of a star-forming region called the "Christmas Tree Cluster," complete with first-ever views of a group of newborn stars still ...

Trumpler 14: Bright young stars mix it up in new image

August 31, 2005

Today the Chandra X-ray Observatory released an image from a research group led by Leisa Townsley of the Penn State Department of Astronomy and Astrophysics. The image of the star cluster Trumpler 14 shows about 1,600 stars ...

Recommended for you

Making stars when the universe was half its age

January 18, 2019

The universe is about 13.8 billion years old, and its stars are arguably its most momentous handiwork. Astronomers studying the intricacies of star formation across cosmic time are trying to understand whether stars and the ...

Saturn hasn't always had rings

January 17, 2019

One of the last acts of NASA's Cassini spacecraft before its death plunge into Saturn's hydrogen and helium atmosphere was to coast between the planet and its rings and let them tug it around, essentially acting as a gravity ...


Adjust slider to filter visible comments by rank

Display comments: newest first

Aug 28, 2009
This comment has been removed by a moderator.
Aug 28, 2009
This comment has been removed by a moderator.
1.8 / 5 (5) Aug 28, 2009
They expand three-dimentionally, opening up energywaves that have the nature of atoms
Compare the expanding Earth theory and variable speed of light theory, for example.
5 / 5 (2) Aug 28, 2009
Current information on research on the putative SMBH at the nucleus of our galaxy can be found at this colorful but concise web page: http://www.astro....roup/gc/ . Does anyone have any credible, peer reviewed published paper that can explain what the stars very near the 4 million solar mass SMBH at galactic center actually orbit? At the same time, such theories must also account for the wide variety of other observed parameters (e.g. diameter less than 40 AU).
5 / 5 (1) Aug 31, 2009
QUESTION -- slightly off topic but i figured this si the best place to ask -- Would dark matter / energy be subject to the same rules of gravitation as ordinary matter .. would it too be condensed in a black hole if it crossed the event horizon?
5 / 5 (1) Sep 01, 2009
Aether Wave Theory
not rated yet Sep 09, 2009
@Question the page 16 you pointed out looks like someone agrees exactly with what I have been saying for many years now. Don't know who wrote it but it is almost exactly what I have been saying every chance I get so naturally I agree. I might even say it is good to see it all put together neatly in this way. How could I disagree when it looks like something I would write myself if I was not so lazy.

Maybe it is just the opposite, with no black hole existing in the center of the Milky Way?

Maybe our rotating galaxy is like a giant magnetic washer with the strongest most concentrated magnetic field in the center. Now this strong magnetic field could "disasemble" stars, ionize the atoms and expel the charged particles out of the opposite poles recycling the galaxy.

Page16 at the link below:


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.