YOU ARE HERE: Home > News & Press > News archive > News 2014 > 3D map shows dusty structure of the Milky Way

I want information on:

Information for:

NEWS ARCHIVE

3D map shows dusty structure of the Milky Way

Last Updated on Monday, 23 June 2014 13:55
Published on Saturday, 21 June 2014 13:23

A team of international astronomers has created a detailed three-dimensional map of the dusty structure of the Milky Way – the star-studded bright disc of our own galaxy – as seen from Earth’s northern hemisphere. The map will be presented by Prof. Janet Drew of the University of Hertfordshire at the National Astronomy Meeting (NAM) 2014 in Portsmouth on Monday 23 June.

Drew 3kpc smallDetail from map at 9000 light years (3 kiloparsec). The map is coloured according to how much dust lies in each direction in the northern Milky Way. The red/brown areas are dustiest directions. Credit: Sale et al/IPHASDust and gas, which make up the interstellar medium (ISM), fill the space between stars in galaxies. The dust in the ISM is shaped by turbulent flows that form intricate fractal structures on scales ranging from thousands of light years down to hundreds of kilometres. Rather than measuring the dust itself to create the map, the team has used observations of more than 38 million stars to estimate how much starlight has been obscured by the ISM and thus how much dust lies in our line of sight to each star. This ‘extinction’ map derives from the newly released catalogue of the Isaac Newton Telescope Photometric H-alpha Survey of the Northern Galactic Plane (IPHAS), the first digital survey to cover the entire northern Milky Way.

"Because the Solar System is embedded in the disc of the Milky Way, our view of it is choked with dust, with the result we know less about its internal structure than we do about some external galaxies, such as M31 in Andromeda." said Drew, the Principal Investigator for the IPHAS survey. "In this Northern survey, we are mainly looking at the parts of the Galactic disc that lie outside the Sun's orbit around the Galactic Centre. This 3-D map demonstrates with greater force than existing 2-D maps that dust in the outer disc does not trace the Perseus spiral arm and other expected structures in a simple way."

The map shows how extinction builds with distance away from the Sun (typically out to 12,000 light years or more) in any part of the surveyed northern Milky Way. Detail on an angular scales 7 times finer than the angular size of the moon is captured. The fractal nature of the ISM is visible in the map, as are large-scale features, such as star-forming molecular clouds and bubbles of ionized gas around clusters of hot stars.

"We can see a number of specific features, including the Rosette Nebula and the star-forming belt in the Perseus Arm of the Milky Way," said Dr Stuart Sale, who led the team that created the map. "Our location within the Milky Way means that we can study the ISM in far greater detail than for any other galaxy.  The knowledge that we gain from studying our own galaxy can subsequently be applied to others."

"IPHAS has been a major part of the Isaac Newton Telescope's programme of observation over the last decade.  It is one of several ground-based surveys beginning to provide important new and very large collections of data, complementing ESA's Gaia mission as it starts its work, that are being discussed at NAM 2014. The common goal is to properly unravel the full 3-D spatial organisation of our own Galaxy" said Drew.

 

Media contacts

NAM 2014 press office landlines: +44 (0) 02392 845176, +44 (0)2392 845177, +44 (0)2392 845178

Dr Robert Massey
Mob: +44 (0)794 124 8035
This email address is being protected from spambots. You need JavaScript enabled to view it.

Anita Heward
Mob: +44 (0)7756 034 243
This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr Keith Smith
This email address is being protected from spambots. You need JavaScript enabled to view it.

An ISDN line is available for radio interviews. To request its use, please contact Sophie Hall via This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Science contacts

Prof. Janet Drew
IPHAS Survey PI
Centre for Astrophysics Research
University of Hertfordshire
This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr Geert Barentsen
Centre for Astrophysics Research
University of Hertfordshire
This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr Stuart Sale
Rudolf Peierls Centre for Theoretical Physics
University of Oxford
This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Images and captions

https://www.ras.org.uk/images/stories/NAM/2014/Drew_1kpc.jpg
https://www.ras.org.uk/images/stories/NAM/2014/Drew_2kpc.jpg
https://www.ras.org.uk/images/stories/NAM/2014/Drew_3kpc.jpg
Each panel is a map coloured according to how much dust lies in each direction in the northern Milky Way, out to a fixed distance. Maps for 3 distances (1, 2 and 3 kiloparsecs or ~3000, ~6000 and ~9000 light years) are shown, using a colour scale that trends to red/brown for the dustiest directions. Credit: Sale et al/IPHAS

https://www.ras.org.uk/images/stories/NAM/2014/Drew_3kpc_small.jpg
Detail from map at 9000 light years (3 kiloparsec). The map is coloured according to how much dust lies in each direction in the northern Milky Way. The red/brown areas are dustiest directions. Credit: Sale et al/IPHAS

 

Further information

The dust map has been published in Sale et al., "A 3D extinction map of the Northern Galactic Plane based on IPHAS photometry", Monthly Notices of the Royal Astronomical Society, in press. A preprint of the paper is available.

The IPHAS catalogue is presented in Barentsen et al, submitted to Monthly Notices of the Royal Astronomical Society. A preprint of the paper is available; see also www.iphas.org/data.shtml

The map can be explored interactively on the IPHAS website at http://www.iphas.org/extinction/

 

Notes for editors

The RAS National Astronomy Meeting (NAM 2014) will bring together more than 600 astronomers, space scientists and solar physicists for a conference running from 23 to 26 June in Portsmouth. NAM 2014, the largest regular professional astronomy event in the UK, will be held in conjunction with the UK Solar Physics (UKSP), Magnetosphere Ionosphere Solar-Terrestrial physics (MIST) and UK Cosmology (UKCosmo) meetings. The conference is principally sponsored by the Royal Astronomical Society (RAS), the Science and Technology Facilities Council (STFC) and the University of Portsmouth. Meeting arrangements and a full and up to date schedule of the scientific programme can be found on the official website and via Twitter.

The University of Portsmouth is a top-ranking university in a student-friendly waterfront city. It's in the top 50 universities in the UK, in The Guardian University Guide League Table 2014 and is ranked in the top 400 universities in the world, in the most recent Times Higher Education World University Rankings 2013. Research at the University of Portsmouth is varied and wide ranging, from pure science – such as the evolution of galaxies and the study of stem cells – to the most technologically applied subjects – such as computer games design. Our researchers collaborate with colleagues worldwide, and with the public, to develop new insights and make a difference to people's lives. Follow the University of Portsmouth on Twitter.

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science. The RAS organises scientific meetings, publishes international research and review journals, recognizes outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 3800 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others. Follow the RAS on Twitter.

The Science and Technology Facilities Council (STFC) is keeping the UK at the forefront of international science and tackling some of the most significant challenges facing society such as meeting our future energy needs, monitoring and understanding climate change, and global security. The Council has a broad science portfolio and works with the academic and industrial communities to share its expertise in materials science, space and ground-based astronomy technologies, laser science, microelectronics, wafer scale manufacturing, particle and nuclear physics, alternative energy production, radio communications and radar. It enables UK researchers to access leading international science facilities for example in the area of astronomy, the European Southern Observatory. Follow STFC on Twitter.

The University of Hertfordshire is the UK’s leading business-facing university and an exemplar in the sector. It is innovative and enterprising and challenges individuals and organisations to excel. The University of Hertfordshire is one of the region’s largest employers with over 2,425 staff and a turnover of over £234 million. With a student community of over 25,100 including more than 2,900 overseas students from 120 different countries, the University has a global network of over 175,000 alumni. It is also one of the top 100 universities in the world under 50 years old, according to the new Times Higher Education 100 under 50 rankings 2014.