These images, taken with NASA's Hubble Space Telescope, reveal fresh star birth in the ancient elliptical galaxy NGC 4150, located about 44 million light-years away.
The images combine observations taken in visible and near-ultraviolet light with Hubble's Wide Field Camera 3. Ultraviolet light traces the glow of young stars.
In the large-scale image, NGC 4150 looks very much like a typical elliptical galaxy. The dark strands of dust in the center, however, provide tentative evidence of a recent galaxy merger. The inset image shows a magnified view of the chaotic activity inside the galaxy's core. Those regions within about 650 light-years of the center that are not obscured by dust appear bright in near-ultraviolet light (shown here in blue). The blue areas indicate a flurry of recent star birth. The stellar breeding ground is about 1,300 light-years across. The stars in this area are less than a billion years old. By comparison, most of the stars in the galaxy are about 10 billion years old. These young stars most likely formed during an encounter with a smaller galaxy that was about one-twentieth the mass of NGC 4150.
The Hubble observations bolster the emerging view that ancient elliptical galaxies like NGC 4150 harbor a significant amount of recent, merger-driven star formation.
The images were taken Oct. 30 and Nov. 9, 2009.
Credits
NASA, ESA, R.M. Crockett (University of Oxford, U.K.), S. Kaviraj (Imperial College London and University of Oxford, U.K.), J. Silk (University of Oxford), M. Mutchler (Space Telescope Science Institute, Baltimore), R. O'Connell (University of Virginia, Charlottesville), and the WFC3 Scientific Oversight Committee| About The Object | |
|---|---|
| Object Name | NGC 4150 |
| Object Description | Elliptical Galaxy |
| R.A. Position | 12h 10m 33.64s |
| Dec. Position | 30° 24' 5.51" |
| Constellation | Coma Berenices |
| Distance | The distance to NGC 4150 is 44 million light-years (13.5 megaparsecs). |
| About The Data | |
| Data Description | This image was created from HST data from proposal : R.M. Crockett (University of Oxford, U.K.). |
| Instrument | HST>WFC3/UVIS |
| Exposure Dates | October 30, 2009, and November 9, 2009, Exposure Time: 3.8 hours |
| Filters | F225W (UV), F438W (B), F555W (V), F657N (H-alpha), and F814W (I) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the WFC3 instrument on the Hubble Space Telescope (HST). Several filters were used to sample broad and narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are as follows: NGC 4150 Wide-field Red: F814W (I) Green: F555W (V) Blue: F438W (B) NGC 4150 Nucleus (inset) Red: F657N (H-alpha) Green: F438W (B) Blue: F225W (UV) |
| 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. |
