News Release Archive:

News Release 10 of 34

September 9, 2009 11:00 AM (EDT)

News Release Number: STScI-2009-25

Hubble Opens New Eyes on the Universe


Image: Capturing the Spectacular Outflow from Markarian 817

Capturing the Spectacular Outflow from Markarian 817STScI-PRC2009-25f

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Rings of brilliant blue stars encircle the bright, active core of this spiral galaxy, whose monster black hole is blasting material into space at 9 million miles an hour.

Viewed nearly face-on, the galaxy, called Markarian 817, shows intense star-forming regions and dark bands of interstellar dust along its spiral arms.

Observations by the new Cosmic Origins Spectrograph (COS) aboard NASA's Hubble Space Telescope captured the powerful outflow of material from this galaxy.

The COS spectrum of Markarian 817 highlights the outflow's dynamic nature. A gas cloud containing hydrogen gas that was detected in Hubble data taken in 1997 does not appear in the COS observation because the cloud has apparently been driven out by an outflow of material from the galaxy.

This discharge is being powered by a huge disk of matter encircling the supermassive black hole, which is 40 million times more massive than our Sun. The disk is driving the material out of the galaxy through powerful winds, produced by streams of charged particles. Some of the outflow rains back onto the galaxy. The rest settles into the intergalactic gas.

Astronomers want to know how much of the outflow lands in the galaxy and how much escapes into intergalactic space. To achieve this, astronomers need high-quality spectroscopic observations to detect the signatures of the outflowing material, which includes carbon, nitrogen, and oxygen. This will allow them to determine the composition, location, and dynamics of the winds that distribute the material.

Markarian 817 is 430 million light-years away in the northern constellation Draco. COS observed the galaxy on August 4, 2009, using its far-ultraviolet detector to distinguish the outflow from the galaxy's core. NASA astronauts installed COS during a servicing mission in May to upgrade and repair the 19-year-old Hubble telescope.

The Hubble image was taken with Hubble's Wide Field Camera 3 on August 2, 2009. The composite image was made by using filters that isolate light from the blue, green, and infrared portions of the spectrum, as well as emission from glowing hydrogen.

The Hubble observations are part of the Hubble Servicing Mission 4 Early Release Observations.

Object Name: Markarian 817

Image Type: Astronomical/Illustration

Credit: NASA, ESA, and the Hubble SM4 ERO Team

Technical facts about this image:

About this Object
Object Name: Markarian 817 (Mrk 817, QSO J1436+5847)
Object Description: Active Galaxy
Position (J2000): R.A. 14h 36m 22s.07
Dec. +58° 47' 39".30
Constellation: Draco
Distance: 430 million light-years (132 million parsecs)
Dimensions: This image is 1.9 arcminutes (232,000 light-years or 71,000 parsecs) wide.
About these Data
Data Description: The Hubble images/spectrum were created from data from proposal 11505: K. Noll (STScI) and J. Green, C. Froning, and B. Keeney (University of Colorado, Boulder).
Instrument: WFC3/UVIS COS/FUV
Exposure Date(s): August 2, 2009 August 4, 2009
Exposure Time: 1.8 hours 1.0 hour
Filters: F438W (B), F555W (V), F680N (H-alpha + [N II]), and F814W (I) G130M (130nm) and G160M (160nm)
About this Image
Credit: NASA, ESA, and the Hubble SM4 ERO Team
Release Date: September 9, 2009
Color: The image is a composite of separate exposures made by the WFC3 instrument on the Hubble Space Telescope. Four filters were used to sample broad and narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are:
F814W (I) red
F680N (H-alpha + [N II]) red
F555W (V) green
F438W (B) blue
Orientation/Scale: Markarian 817
Acknowledgments for Markarian 817
Observers: K. Noll (STScI) and J. Green, C. Froning, and B. Keeney (University of Colorado, Boulder)
Data Analysis: J. Anderson and M. Mutchler (STScI), and C. Froning and J. Green (University of Colorado, Boulder)
Image Composition: Z. Levay and L. Frattare (STScI)
Text: L. Frattare, D. Weaver and R. Villard (STScI)
Illustrations: A. Feild and Z. Levay (STScI)
Video Animation: G. Bacon (STScI)
Science Consultants: M. Livio (STScI) and C. Froning and J. Green (University of Colorado, Boulder)


The above montage includes these images:

Markarian 817 Image Type: Astronomical Markarian 817 Markarian 817 COS Spectrum Image Type: Illustration Markarian 817 COS Spectrum

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