Capturing the spectacular outflow from Markarian 817: Rings of brilliant blue stars encircle the bright, active core of this spiral galaxy, whose monster black hole is blasting material into space at over 14 million kilometres per 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 the NASA/ESA 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 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 disc of matter encircling the supermassive black hole, which is 40 million times more massive than our Sun. The disc 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, they 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 of Draco. COS observed the galaxy on 4 August 2009, using its far-ultraviolet detector to distinguish the outflow from the galaxy’s core. NASA astronauts installed COS during Servicing Mission 4 in May to upgrade and repair the 19-year-old Hubble. The Hubble image was taken with the Wide Field Camera 3 on 2 August 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.

Name: Markarian 817
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Activity : AGN
Category: Quasars and Black Holes
Constellation: Draco
Distance: 450 million light years
Release date: 9 September 2009, 17:00
Credit: NASA, ESA and the Hubble SM4 ERO Team

Barred spiral galaxy NGC 6217: This is the first image of a celestial object taken with the newly repaired Advanced Camera for Surveys (ACS). The camera was restored to operation during the STS-125 Servicing Mission to upgrade the NASA/ESA Hubble Space Telescope. The barred spiral galaxy NGC 6217 was photographed on 13 June and 8 July 2009, as part of the initial testing and calibration of Hubble’s ACS. The galaxy lies up to 90 million light-years away in the north circumpolar constellation Ursa Major.

Name: NGC 6217
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Type : Barred
Category: Galaxies
Constellation: Ursa Minor
Distance: 90 million light years
Release date: 9 September 2009, 17:00
Credit: NASA, ESA and the Hubble SM4 ERO Team

Digitized sky survey image of Abell 370 (ground-based image): This image is a colour composite made from exposures from the Digitized Sky Survey 2 (DSS2). The field of view is approximately 2.2 x 2.2 degrees.

Name: Abell 370
Type: Early Universe : Galaxy : Grouping : Cluster
Category: Galaxies
Constellation: Cetus
Distance: z=0.375 (redshift)
Release date: 9 September 2009, 17:00
Credit: NASA, ESA and Digitized Sky Survey 2. Acknowledgment: Davide De Martin.

Ram pressure stripping galaxies NGC 4522 and NGC 4402: This composite shows the two ram pressure stripping galaxies NGC 4402 and NGC 4522. Hubble's Advanced Camera for Surveys (ACS) allows astronomers to study an interesting and important phenomenon called ram pressure stripping that is so powerful, it is capable of mangling galaxies and even halting their star formation. The first image shows NGC 4402 and highlights some telltale signs of ram pressure stripping such as the curved, or convex, appearance of the disc of gas and dust, a result of the forces exerted by the heated gas. Light being emitted by the disc backlights the swirling dust that is being swept out by the gas. Studying ram pressure stripping helps astronomers better understand the mechanisms that drive the evolution of galaxies, and how the rate of star formation is suppressed in very dense regions of the Universe like clusters. The second image, NGC 4522, is a spectacular example of a spiral galaxy that is currently being stripped of its gas content. The galaxy is part of the Virgo galaxy cluster and its rapid motion within the cluster results in strong winds across the galaxy as the gas within is leftNGC 4522 behind. Scientists estimate that the galaxy is moving at more than 10 million kilometres per hour. A number of newly formed star clusters that developed in the stripped gas can be seen in the Hubble image. The stripped spiral galaxy is located some 60 million light-years away from Earth.

Name: NGC 4402, NGC 4522
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Type : Barred
Category: Galaxies
Release date: 30 September 2009, 15:00
Credit: NASA & ESA

Hubble views NGC 4522: Hubble's Advanced Camera for Surveys (ACS) allows astronomers to study an interesting and important phenomenon called ram pressure stripping that is so powerful, it is capable of mangling galaxies and even halting their star formation. NGC 4522 is a spectacular example of a spiral galaxy that is currently being stripped of its gas content. The galaxy is part of the Virgo galaxy cluster and its rapid motion within the cluster results in strong winds across the galaxy as the gas within is left behind. Scientists estimate that the galaxy is moving at more than 10 million kilometres per hour. A number of newly formed star clusters that developed in the stripped gas can be seen in the Hubble image. The stripped spiral galaxy is located some 60 million light-years away from Earth. Even though it is a still image, Hubble's view of NGC 4522 practically swirls off the page with apparent movement. It highlights the dramatic state of the galaxy with an especially vivid view of the ghostly gas being forced out of it. Bright blue pockets of new star formation can be seen to the right and left of centre.

Name: NGC 4522
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Type : Barred
Category: Galaxies
Constellation: Virgo
Distance: 60 million light years
Release date: 30 September 2009, 15:00
Credit: NASA & ESA

Hubble views NGC 4402: The image of NGC 4402 highlights some telltale signs of ram pressure stripping such as the curved, or convex, appearance of the disc of gas and dust, a result of the forces exerted by the heated gas. Light being emitted by the disc backlights the swirling dust that is being swept out by the gas. Studying ram pressure stripping helps astronomers better understand the mechanisms that drive the evolution of galaxies, and how the rate of star formation is suppressed in very dense regions of the Universe like clusters.

Name: NGC 4402
Type: Milky Way : Galaxy : Type : Spiral
Category: Galaxies
Constellation: Virgo
Distance: 55 million light years
Release date: 30 September 2009, 15:00
Credit: NASA & ESA