In this whimsical image, we encounter a cluster of stars situated near a molecular cloud. Called NGC 3572, this starscape can be found around 6,500 light-years from Earth in the constellation of Carina.
This view, which was acquired by the Wide Field Imager on the MPG/ESO 2.2-meter telescope at ESO’s La Silla Observatory, captures the cluster at a pivotal point in its evolution. Despite their young age, the stars will only live a fraction of the time their lesser-counterparts (like the Sun) will. In fact, they are so massive, they will explode as supernovae in a few millions of years.
Importantly, the image gives insight into the gas-sculpted bubbles surrounding the central stars, which form as a result of intense stellar winds. In the case of NGC 3572, they are merely a symptom of their chaotic environment, whereby the stars did not form alone, but with multiple partners.
As you can see, they’ve had a rather beautiful impact on their surroundings, including the molecular cloud from which they were born (seen in black). Gradually, as the stars took shape, the stellar winds started carving huge chunks out of the gas, setting the rest of it alight.
This is an odd couple of very different glowing gas clouds in the Large Magellanic Cloud, one of the Milky Way’s satellite galaxies. NGC 2020 (left), is round and blue while NGC 2014 (right) is irregularly shaped and red. These very different forms were both created by powerful stellar winds from newborn stars that also radiate into the gas, causing it to glow brightly. image credit: European Southern Observatory
The spiral galaxy NGC 3627 is located about 30 million light years from Earth. This composite image includes X-ray data from NASA’s Chandra X-ray Observatory (blue), infrared data from the Spitzer Space Telescope (red), and optical data from the Hubble Space Telescope and the Very Large Telescope (yellow). The inset shows the central region, which contains a bright X-ray source that is likely powered by material falling onto a supermassive black hole. A search using archival data from previous Chandra observations of a sample of 62 nearby galaxies has shown that 37 of the galaxies, including NGC 3627, contain X-ray sources in their centers. Most of these sources are likely powered by central supermassive black holes. The survey, which also used data from the Spitzer Infrared Nearby Galaxy Survey, found that seven of the 37 sources are new supermassive black hole candidates.
Confirming previous Chandra results, this study finds the fraction of galaxies found to be hosting supermassive black holes is much higher than found with optical searches. This shows the ability of X-ray observations to find black holes in galaxies where relatively low-level black hole activity has either been hidden by obscuring material or washed out by the bright optical light of the galaxy.
The combined X-ray and infrared data suggest that the nuclear activity in a galaxy is not necessarily related to the amount of star-formation in the galaxy, contrary to some early claims. In contrast, these new results suggest that the mass of the supermassive black hole and the rate at which the black hole accretes matter are both greater for galaxies with greater total masses.
A paper describing these results was published in the April 10, 2011 issue of The Astrophysical Journal. The authors are Catherine Grier and Smita Mathur of The Ohio State University in Columbus, OH; Himel GHosh of CNRS/CEA-Saclay in Guf-sur-Yvette, France and Laura Ferrarese from Herzberg Institute of Astrophysics in Victoria, Canada.
NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra’s science and flight operations from Cambridge, Mass.
Image Credit: NASA/CXC/Ohio State Univ./C.Grier et al.; Optical: NASA/STScI, ESO/WFI; Infrared: NASA/JPL-Caltech