Featured Research

from universities, journals, and other organizations

A new 3-D map of the interstellar gas within 300 parsecs from the sun

Date:
February 15, 2010
Source:
Astronomy & Astrophysics
Summary:
Astronomy & Astrophysics is publishing new 3-D maps of the interstellar gas in the local area around our sun. A French-American team of astronomers presents new absorption measurements towards more than 1800 stars. They were able to characterize the properties of the interstellar gas within each sight line.

Map of partially ionized interstellar gas within 300 parsecs around the Sun, as viewed in the Galactic plane. Triangles represent the sight-line positions of the stars used to produce the map. White to dark shading represents the low to high values of the gas density, and orange shading is for areas with no reliable measurement. The Local Cavity is shown as the white area of low density gas that surrounds the Sun at about 80 parsecs.
Credit: Image courtesy of Astronomy & Astrophysics

Astronomy & Astrophysics is publishing new 3D maps of the interstellar gas in the local area around our Sun. A French-American team of astronomers presents new absorption measurements towards more than 1800 stars. They were able to characterize the properties of the interstellar gas within each sight line.

This week, Astronomy & Astrophysics publishes new 3D maps of the interstellar gas situated in an area 300 parsecs around the Sun. A French-American team of astronomers presents new measurements of the absorption by the interstellar gas in the Sun's local area. Knowledge of the interstellar medium properties, including the spatial distribution, dynamics, and the chemical and physical characteristics, allow astronomers to better understand the interplay between the evolution of stars and their exchange of matter with the ambient interstellar medium. The local area around our Sun has been studied with many surveys at various wavelengths, but the whole picture is still far from being either complete or fully understood.

The team, led by Barry Y. Welsh and his colleagues R. Lallement and J.-L. Vergely, presents new, high spectral resolution measurements of the calcium (CaII) K line (at 3933 ) and the sodium doublet (at 5889 and 5895 ). These absorption lines have long been used to study the interstellar medium. The CaII K lines were first observed in 1904 by German astronomer J. Hartmann, in the spectrum of the star δ Orionis. This first detection of interstellar gas set the stage for the early studies of interstellar medium. The sodium (NaI) doublet was later discovered in 1919 toward δ Orionis and β Scorpii. The CaII K line and the NaI doublet are complementary: the first one is sensitive to partially ionized gas, and the second one traces cold and neutral interstellar gas.

The team combined their new data (mostly recorded at the European Southern Observatory in Chile) with previously published results. The new paper represents a catalog of absorption measurements towards 1857 stars located 800 parsecs from the Sun. 1 shows the NaI map of the interstellar gas density within 300 parsecs. The white area surrounding the Sun (i.e., at the center of the map) corresponds to a very low-density area of neutral gas, known as the Local Cavity. It is about 80 parsecs in radius in most directions and is surrounded by a highly fragmented "wall" of dense neutral gas. The various gaps in the wall are termed "interstellar tunnels" and represent rarefied pathways into other surrounding interstellar cavities. Maps of the distribution of CaII have never been made before, and they reveal that the Local Cavity contains numerous filamentary structures of partially ionized gas that appear to form in a honeycomb-like pattern of small interstellar cells.

Theories of the general interstellar medium require that large rarefied cavities exist, having been formed by the combined action of energetic supernova events and the outflowing winds of clusters of hot and young stars. The history of our Local Cavity, within which the Sun resides, is still speculative, but many believe that it was created about 15 million years ago by a series of supernova outbursts, with the last re-heating happening about 3 million years ago.


Story Source:

The above story is based on materials provided by Astronomy & Astrophysics. Note: Materials may be edited for content and length.


Journal Reference:

  1. Welsh et al. New 3D gas density maps of NaI and CaII interstellar absorption within 300 pc. Astronomy and Astrophysics, 2010; 510A54 DOI: 10.1051/0004-6361/200913202

Cite This Page:

Astronomy & Astrophysics. "A new 3-D map of the interstellar gas within 300 parsecs from the sun." ScienceDaily. ScienceDaily, 15 February 2010. <www.sciencedaily.com/releases/2010/02/100209152225.htm>.
Astronomy & Astrophysics. (2010, February 15). A new 3-D map of the interstellar gas within 300 parsecs from the sun. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2010/02/100209152225.htm
Astronomy & Astrophysics. "A new 3-D map of the interstellar gas within 300 parsecs from the sun." ScienceDaily. www.sciencedaily.com/releases/2010/02/100209152225.htm (accessed October 21, 2014).

Share This



More Space & Time News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins