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Collection:
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NASA Planetary Photo Journal Collection
Collection
NASA Planetary Photo Journal Collection
Collection
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Title:
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Galactic Halos of Hydrogen
Title
Galactic Halos of Hydrogen
Title
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Original Caption Released with Image:
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This image shows two companion galaxies, NGC 4625 (top) and NGC 4618 (bottom), and their surrounding cocoons of cool hydrogen gas (purple). The huge set of spiral arms on NGC 4625 (blue) was discovered by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. Though these arms are nearly invisible when viewed in optical light, they glow brightly in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light.
The vibrant spiral arms are also quite lengthy, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far.
Astronomers do not know why NGC 4625 grew arms while NGC 4618 did not. The purple nebulosity shown here illustrates that hydrogen gas - an ingredient of star formation - is diffusely distributed around both galaxies. This means that other unknown factors led to the development of the arms of NGC 4625.
Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own.
The image is composed of ultraviolet, visible-light and radio data, from the Galaxy Evolution Explorer, the California Institute of Technology's Digitized Sky Survey, and the Westerbork Synthesis Radio Telescope, the Netherlands, respectively. Near-ultraviolet light is colored green; far-ultraviolet light is colored blue; and optical light is colored red. Radio emissions are colored purple.
Original_Caption_Rel eased_with_Image
This image shows two companion galaxies, NGC 4625 (top) and NGC 4618 (bottom), and their surrounding cocoons of cool hydrogen gas (purple). The huge set of spiral arms on NGC 4625 (blue) was discovered by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. Though these arms are nearly invisible when viewed in optical light, they glow brightly in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light.
The vibrant spiral arms are also quite lengthy, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far.
Astronomers do not know why NGC 4625 grew arms while NGC 4618 did not. The purple nebulosity shown here illustrates that hydrogen gas - an ingredient of star formation - is diffusely distributed around both galaxies. This means that other unknown factors led to the development of the arms of NGC 4625.
Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own.
The image is composed of ultraviolet, visible-light and radio data, from the Galaxy Evolution Explorer, the California Institute of Technology's Digitized Sky Survey, and the Westerbork Synthesis Radio Telescope, the Netherlands, respectively. Near-ultraviolet light is colored green; far-ultraviolet light is colored blue; and optical light is colored red. Radio emissions are colored purple.
Original Caption Released with Image
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Image Credit:
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NASA/JPL-Caltech/Car negie Observatories/WSRT
Image_Credit
NASA/JPL-Caltech/Car negie Observatories/WSRT
Image Credit
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Produced By:
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California Institute of Technology
Produced_By
California Institute of Technology
Produced By
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Mission:
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Galaxy Evolution Explorer (GALEX)
Mission
Galaxy Evolution Explorer (GALEX)
Mission
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Spacecraft:
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GALEX Orbiter
Spacecraft
GALEX Orbiter
Spacecraft
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Target Name:
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NGC 4625
Target_Name
NGC 4625
Target Name
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Instrument:
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Ultraviolet/Visible Camera
Instrument
Ultraviolet/Visible Camera
Instrument
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Product Size:
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872 samples x 872 lines
Product_Size
872 samples x 872 lines
Product Size
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facet_what:
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Ultraviolet/Visible Camera
facet_what
Ultraviolet/Visible Camera
facet_what
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facet_what:
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Explorer
facet_what
Explorer
facet_what
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facet_what:
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Galaxy Evolution Explorer
facet_what
Galaxy Evolution Explorer
facet_what
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facet_what:
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GALEX
facet_what
GALEX
facet_what
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facet_what:
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GALEX Orbiter
facet_what
GALEX Orbiter
facet_what
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facet_what:
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Canes Venatici
facet_what
Canes Venatici
facet_what
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facet_where:
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California
facet_where
California
facet_where
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facet_where:
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Netherlands
facet_where
Netherlands
facet_where
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facet_where:
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Jet Propulsion Laboratory (JPL)
facet_where
Jet Propulsion Laboratory (JPL)
facet_where
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Image #:
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PIA03540
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UID:
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SPD-PHOTJ-PIA03540
UID
SPD-PHOTJ-PIA03540
UID
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orignial url:
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orignial_url
orignial url
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