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(Last updated 3/20/00)Photos also available in larger TIFF format images. Contact Pam Frost at (614) 292-9475. - Coverage of OSU Research
PEERING INTO THE DUSTY HEART OF AN ACTIVE GALAXY
This collage of visible and infrared images shows the clouds of interstellar dust and gas falling into the center of the active galaxy Markarian 573. This galaxy has an unusually bright nucleus that was first noted in 1978 by the late Armenian astronomer B.E. Markarian who cataloged this and similar galaxies.
The black-and-white image on the upper left was taken with the NASA Hubble Space Telescope's visible-light camera, the Wide Field and Planetary Camera 2 (WFPC2). It shows the main body of this nearly face-on spiral galaxy. The blue box at the center surrounds a narrower view taken by the Hubble telescope's infrared camera, the Near Infrared Camera and Multi-Object Spectrometer (NICMOS).
By forming the ratio of the visible and near-infrared images, shown in the picture at the lower right, the central starlight and bright nucleus of the galaxy are suppressed, revealing clouds of dust (dark regions) strung along a pair of broken spiral arms surrounding the active nucleus at the very center. Gas and dust in these arms is thought to be flowing into the center where it will eventually feed an active supermassive black hole. Gas that has already reached the center falls into this black hole and heats up violently, causing it to shine brightly at wavelengths from X-rays to radio waves.
The WFPC2 image was taken in October 1994 using a near-infrared filter (8269 Angstroms), and acquired from the HST Data Archive. The NICMOS image was taken in August 1998 using a filter with a wavelength of 16,000 Angstroms. This image was taken as part of a study of 24 similarly active galaxies by the investigators.
DUSTY SPIRALS FEEDING GAS TO HUNGRY CENTRAL BLACK HOLES
The six images in this montage show dusty spirals of interstellar gas found in the hearts of active galaxies by the Hubble Space Telescope's visible and near-infrared cameras.
By combining visible and near-infrared images
of the centers of these galaxies, astronomers can supress the
light from the billions of stars in the centers, revealing dark
clouds of interstellar dust and gas. These dark clouds are seen
spiralling inwards towards the very centers of the galaxies where
it may
ultimately be consumed by a supermassive black hole at the center.
As the gas and dust falls into the black hole, it is heated violently,
causing it to shine out at wavelengths from X-rays to radio waves,
making the nucleus appear nearly as bright as the billions of
stars around it. It is this brilliant release of energy the centers
of these galaxies that has made them objects of particular interest.
The visible wavelength images were taken by the NASA Hubble Space Telescope's visible-light camera, the Wide Field and Planetary Camera 2 (WFPC2) during 1994 and 1995, and acquired from the HST Data Archives. The infrared images were taken by the Hubble telescope's infrared camera, the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), during 1998.