Astronomers Use Hubble and Keck to Identify Dwarf Galaxy
Title
Astronomers Use Hubble and Keck to Identify Dwarf Galaxy
Title
Object Name:
SDSS J0737 3216
Object_Name
SDSS J0737 3216
Object Name
Object Name:
SLACS J0737 3216
Object_Name
SLACS J0737 3216
Object Name
General Information:
What is a News Nugget?
News Nuggets are bulletins from the world of astronomy.
A team of astronomers at the University of California at Santa Barbara report that they have resolved a dwarf galaxy 6 billion light-years away. Weighing only 1/100 as much as our Milky Way Galaxy, the dwarf is much smaller than anything studied before in any detail at this distance.
They report in the Dec. 20 issue of the Astrophysical Journal that the galaxy looks very similar to one of the dwarf galaxies in the Virgo cluster, which is located only 60 million light-years away. "We believe we may have identified the progenitors of local dwarf galaxies," says Tommaso Treu. "We see them as clearly as we would see dwarfs in the Virgo cluster using ground-based telescopes. The sharp view of NASA's Hubble Space Telescope, and the laser guide stars adaptive optics system on the W.M. Keck Telescope, were aimed at a natural lens in space, called a gravitational lens, to study the dwarf. The researchers took advantage of the fact that the distant dwarf galaxy lies behind a massive foreground galaxy that bends light rays much as a glass lens does. This gravitational lensing amplifies the image of the much farther dwarf galaxy, making it appear 10 times brighter and 10 times larger than it would normally be seen by either Hubble or Keck.
General_Information
What is a News Nugget?
News Nuggets are bulletins from the world of astronomy.
A team of astronomers at the University of California at Santa Barbara report that they have resolved a dwarf galaxy 6 billion light-years away. Weighing only 1/100 as much as our Milky Way Galaxy, the dwarf is much smaller than anything studied before in any detail at this distance.
They report in the Dec. 20 issue of the Astrophysical Journal that the galaxy looks very similar to one of the dwarf galaxies in the Virgo cluster, which is located only 60 million light-years away. "We believe we may have identified the progenitors of local dwarf galaxies," says Tommaso Treu. "We see them as clearly as we would see dwarfs in the Virgo cluster using ground-based telescopes. The sharp view of NASA's Hubble Space Telescope, and the laser guide stars adaptive optics system on the W.M. Keck Telescope, were aimed at a natural lens in space, called a gravitational lens, to study the dwarf. The researchers took advantage of the fact that the distant dwarf galaxy lies behind a massive foreground galaxy that bends light rays much as a glass lens does. This gravitational lensing amplifies the image of the much farther dwarf galaxy, making it appear 10 times brighter and 10 times larger than it would normally be seen by either Hubble or Keck.
About the Object Object Name: SDSS J0737 3216, SLACS J0737 3216 Object Description: Gravitational Lens System Position (J2000): R.A. 07h 37m 28s.44 Dec. 32° 16' 18".47 Constellation: Gemini Distance: The background source that is being lensed has a distance of 6 billion light-years (1.8 billion parsecs). Redshift: The foreground lensing object is at a redshift z = 0.3223; the background source that is being lensed has a redshift z = 0.5812. About the Data Data Description:
The Hubble image was created from HST data from proposal 10494: L. Koopmans (Kapteyn Astronomical Institute), T. Treu (University of California, Santa Barbara), A. Bolton (Institute for Astronomy/University of Hawaii), S. Burles (Massachusetts Institute of Technology), and L. Moustakas (Jet Propulsion Laboratory).
The science team includes P. Marshall and T. Treu (University of California, Santa Barbara), J. Melbourne (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz), R. Gavazzi (University of California, Santa Barbara), K. Bundy (University of Toronto), M. Ammons (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz), A. Bolton (Institute for Astronomy/University of Hawaii), S. Burles (Massachusetts Institute of Technology), J. Larkin (University of California, Los Angeles), D. Le Mignant (W. M. Keck Observatory; Center for Adaptive Optics, University of California, Santa Cruz), D. Koo (U.C.O./Lick Observatory University of California, Santa Cruz), L. Koopmans (Kapteyn Astronomical Institute), and C. Max (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz).
Instrument: Hubble: ACS/WFC Hubble: NICMOS/NIC2 Keck II/ LGSAO Exposure Date(s): November 5, 2006 November 5, 2006 December 11, 2006 Exposure Time: 75 minutes 43 minutes 52 minutes Filters: F555W (V) and F814W (I) F160W K’-band with the near-infrared camera (NIRC2) About the Image Image Credit: NASA, ESA, and P. Marshall and T. Treu (University of California, Santa Barbara) Release Date: October 4, 2007
Fast_Facts
Technical facts about this news release:
About the Object Object Name: SDSS J0737 3216, SLACS J0737 3216 Object Description: Gravitational Lens System Position (J2000): R.A. 07h 37m 28s.44 Dec. 32° 16' 18".47 Constellation: Gemini Distance: The background source that is being lensed has a distance of 6 billion light-years (1.8 billion parsecs). Redshift: The foreground lensing object is at a redshift z = 0.3223; the background source that is being lensed has a redshift z = 0.5812. About the Data Data Description:
The Hubble image was created from HST data from proposal 10494: L. Koopmans (Kapteyn Astronomical Institute), T. Treu (University of California, Santa Barbara), A. Bolton (Institute for Astronomy/University of Hawaii), S. Burles (Massachusetts Institute of Technology), and L. Moustakas (Jet Propulsion Laboratory).
The science team includes P. Marshall and T. Treu (University of California, Santa Barbara), J. Melbourne (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz), R. Gavazzi (University of California, Santa Barbara), K. Bundy (University of Toronto), M. Ammons (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz), A. Bolton (Institute for Astronomy/University of Hawaii), S. Burles (Massachusetts Institute of Technology), J. Larkin (University of California, Los Angeles), D. Le Mignant (W. M. Keck Observatory; Center for Adaptive Optics, University of California, Santa Cruz), D. Koo (U.C.O./Lick Observatory University of California, Santa Cruz), L. Koopmans (Kapteyn Astronomical Institute), and C. Max (U.C.O./Lick Observatory/Center for Adaptive Optics, University of California, Santa Cruz).
Instrument: Hubble: ACS/WFC Hubble: NICMOS/NIC2 Keck II/ LGSAO Exposure Date(s): November 5, 2006 November 5, 2006 December 11, 2006 Exposure Time: 75 minutes 43 minutes 52 minutes Filters: F555W (V) and F814W (I) F160W K’-band with the near-infrared camera (NIRC2) About the Image Image Credit: NASA, ESA, and P. Marshall and T. Treu (University of California, Santa Barbara) Release Date: October 4, 2007
Fast Facts
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*Image Type:*: Astronomical/Illustr ation
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*Image Type:*: Astronomical/Illustr ation
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*Release Date*:October 4, 2007 02:00 PM (EDT)
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*Release Date*:October 4, 2007 02:00 PM (EDT)
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*News Release Number:*: STScI-2007-38a
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*News Release Number:*: STScI-2007-38a
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*Title*:Astronomers Use Hubble and Keck to Identify Dwarf Galaxy
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*Title*:Astronomers Use Hubble and Keck to Identify Dwarf Galaxy
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*Description*:
This photo illustration shows a tiny galaxy 6 billion light-years away that is smaller than any galaxy ever seen at that distance.
Astronomers discovered this distant galaxy through a phenomenon called gravitational lensing. This phenomenon occurs when a massive galaxy in the foreground bends the light rays from a distant galaxy behind it in much the same way as a magnifying glass does. When both galaxies are exactly lined up, the light forms a bull's-eye pattern, called an "Einstein ring," around the foreground galaxy.
This ring can be seen in the illustration. Einstein rings are named for physicist Albert Einstein, who predicted the phenomenon. By focusing the light rays, this gravitational lensing effect increases the observed brightness and size of the background galaxy by more than 10 times.
The illustration is based on images taken in infrared light from the W. M. Keck Telescope and visible-light images from NASA's Hubble Space Telescope. The Hubble and Keck data reveal information about the early years of the infant galaxy, namely that it is seen just after it formed most of its stars.
The Hubble images were taken on Nov. 5, 2006 with the Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer. The Keck images were taken on Dec. 11, 2006.
For additional information, contact:
Ray Villard Space Telescope Science Institute, Baltimore, Md. 410-338-4514 villard@stsci.edu
Tommaso Treu University of California, Santa Barbara 805-893-3503 tt@physics.ucsb.edu
note
*Description*:
This photo illustration shows a tiny galaxy 6 billion light-years away that is smaller than any galaxy ever seen at that distance.
Astronomers discovered this distant galaxy through a phenomenon called gravitational lensing. This phenomenon occurs when a massive galaxy in the foreground bends the light rays from a distant galaxy behind it in much the same way as a magnifying glass does. When both galaxies are exactly lined up, the light forms a bull's-eye pattern, called an "Einstein ring," around the foreground galaxy.
This ring can be seen in the illustration. Einstein rings are named for physicist Albert Einstein, who predicted the phenomenon. By focusing the light rays, this gravitational lensing effect increases the observed brightness and size of the background galaxy by more than 10 times.
The illustration is based on images taken in infrared light from the W. M. Keck Telescope and visible-light images from NASA's Hubble Space Telescope. The Hubble and Keck data reveal information about the early years of the infant galaxy, namely that it is seen just after it formed most of its stars.
The Hubble images were taken on Nov. 5, 2006 with the Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer. The Keck images were taken on Dec. 11, 2006.
For additional information, contact:
Ray Villard Space Telescope Science Institute, Baltimore, Md. 410-338-4514 villard@stsci.edu
Tommaso Treu University of California, Santa Barbara 805-893-3503 tt@physics.ucsb.edu
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facet_what:
Advanced Camera for Surveys
facet_what
Advanced Camera for Surveys
facet_what
facet_what:
Virgo
facet_what
Virgo
facet_what
facet_what:
NICMOS
facet_what
NICMOS
facet_what
facet_what:
Multi-Object Spectrometer
facet_what
Multi-Object Spectrometer
facet_what
facet_what:
Spectrometer
facet_what
Spectrometer
facet_what
facet_what:
Keck Observatory
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Keck Observatory
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facet_what:
Gemini
facet_what
Gemini
facet_what
facet_what:
Galaxy 6
facet_what
Galaxy 6
facet_what
facet_what:
Hubble Space Telescope (HST)
facet_what
Hubble Space Telescope (HST)
facet_what
facet_what:
Near Infrared Camera and Multi-Object Spectrometer (NICMOS)
facet_what
Near Infrared Camera and Multi-Object Spectrometer (NICMOS)
