The glowing spiral arms of NGC 6744
Dwarf galaxy UGCA 281
Messier 66 — member of the Leo Triplet
Wave of star formation in Messier 96
Parts of Messier 106
Using the unparalleled sharpness and
ultraviolet observational capabilities of the NASA/ESA Hubble Space
Telescope, an international team of astronomers has created the most
comprehensive high-resolution ultraviolet-light survey of star-forming
galaxies in the local Universe. The catalogue contains about 8000
clusters and 39 million hot blue stars.
Ultraviolet light is a major tracer of the youngest and hottest
stars. These stars are short-lived and intensely bright. Astronomers
have now finished a survey called LEGUS (Legacy ExtraGalactic UV Survey)
that captured the details of 50 local galaxies within 60 million
light-years of Earth in both visible and ultraviolet light.
The LEGUS team carefully selected its targets from among 500
candidate galaxies compiled from ground-based surveys. They chose the
galaxies based on their mass, star-formation rate, and their abundances
of elements heavier than hydrogen and helium.
Because of the proximity of the selected galaxies, Hubble was able to
resolve them into their main components: stars and star clusters. With
the LEGUS data, the team created a catalogue with about 8000 young
clusters and it also created a star catalogue comprising about 39
million stars that are at least five times more massive than our Sun.
The data, gathered with Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys, provide detailed information on young, massive stars and star clusters,
and how their environment affects their development. As such, the
catalogue offers an extensive resource for understanding the
complexities of star formation and galaxy evolution.
One of the key questions the survey may help astronomers answer is
the connection between star formation and the major structures, such as spiral arms, that make up a galaxy. These structured distributions are particularly visible in the youngest stellar populations.
By resolving the fine details of the studied galaxies, while also
studying the connection to larger galactic structures, the team aims to
identify the physical mechanisms behind the observed distribution of
stellar populations within galaxies.
Figuring out the final link between gas and star formation is key to
fully understanding galaxy evolution. Astronomers are studying this link
by looking at the effects of the environment on star clusters, and how
their survival is linked to their surroundings.
LEGUS will not only allow astronomers to understand the local
Universe. It will also help interpret views of distant galaxies, where
the ultraviolet light from young stars is stretched to infrared
wavelengths due to the expansion of space. The NASA/ESA/CSA James Webb Space Telescope and its ability to observe in the far infrared will complement the LEGUS views.
More Information
More Information
Image credit: NASA, ESA, LEGUS team
Links
Contacts
Linda Smith
European Space Agency
Baltimore, Maryland, USA
Tel: 001 4103384926
Email: lsmith@stsci.edu
Mathias Jäger
ESA/Hubble, Public Information Officer
Garching bei München, Germany
Cell: +49 176 62397500
Email: mjaeger@partner.eso.org
Source: ESA/Hubble/News
