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.
Credits
NASA, ESA, and the Hubble SM4 ERO Team| About The Object | |
|---|---|
| Object Name | Markarian 817, Mrk 817, QSO J1436+5847 |
| Object Description | Active Galaxy |
| R.A. Position | 14h 36m 22.07s |
| Dec. Position | 58° 47' 39.3" |
| Constellation | Draco |
| Distance | 430 million light-years (132 million parsecs) |
| Dimensions | The galaxy image is 1.9 arcminutes (232,000 light-years or 71,000 parsecs) wide. |
| About The Data | |
| Data Description | The Hubble images/spectrum were created from data from proposal : K. Noll (STScI) and J. Green, C. Froning, and B. Keeney (University of Colorado, Boulder). 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) |
| Instrument | HST>WFC3/UVIS (galaxy) and HST>COS/FUV (spectra) |
| Exposure Dates | August 2, 2009, Exposure Time: 1.8 hours (galaxy) and August 4, 2009, Exposure Time: 1.0 hour (spectra) |
| Filters | WFC3/UVIS: F438W (B), F555W (V), F680N (H-alpha + [N II]), and F814W (I) COS spectra: G130M (130nm) and G160M (160nm) |
| About The Image | |
| Color Info | The galaxy 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: Blue: F438W (B) Green: F555W (V) Red: F680N (H-alpha + [N II]) + F814W (I) |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
