Using a distant quasar as a cosmic flashlight, a new instrument aboard NASA's Hubble Space Telescope has begun probing the invisible, skeletal structure of the universe.
Called the cosmic web, it is the diffuse, faint gas located in the space between galaxies. More than half of all normal matter resides outside of galaxies. By observing the cosmic web, astronomers can probe the raw materials from which galaxies form, and determine how this gas was assembled into the complex structures of the present-day universe.
Using the light from the quasar PKS 0405-123, located 7 billion to 8 billion light-years away, the newly installed Cosmic Origins Spectrograph (COS) on Hubble probed a string of gas clouds residing along the light path at different distances. Quasars are the bright cores of active galaxies and are powered by supermassive black holes. Thousands of quasars have been observed, all at extreme distances from our Milky Way galaxy. The most luminous quasars radiate at a rate equivalent to a trillion suns.
The COS spectrum shown here reveals the absorption lines of elements that make up the intervening gas clouds traversed by the quasar's light. COS detected three to five times more lower-density filaments of hydrogen in the cosmic web than were seen in previous observations along this line of sight. The instrument also detected evidence of glowing oxygen and nitrogen that predominantly trace strong shocks in the filamentary cosmic web.
These shocks are produced by gravitational interactions between intergalactic clouds of gas falling onto filaments in the web and by the fast outflow of material from star-forming galaxies.
COS produced this spectrum and detected many previously unseen filaments in only a quarter of the time it took to produce spectra in previous studies of this object (using earlier instruments). The spectrum is also of higher quality (with a better signal-to-noise ratio) than those spectra produced by the best previous observations.
With the COS, astronomers have access to thousands of quasars where only a handful could be observed before in the ultraviolet. Each quasar sightline passes through multiple filaments of the cosmic web, providing a picture of how intergalactic spaces evolve over time, as light passes from the quasar to us.
These data are the first in a series of large observation programs that will map out the cosmic web. The studies will trace the complex cycles of how material flows between galaxies and intergalactic space.
COS observed the quasar in far-ultraviolet light in August 2009. The instrument was installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.
These Hubble observations of the quasar PKS 0405-123 are part of the Hubble Servicing Mission 4 Early Release Observations.
Credits
NASA, ESA, the Hubble SM4 ERO Team, and Digitized Sky Survey| About The Object | |
|---|---|
| Object Name | PKS 0405-123 |
| Object Description | Quasar/Active Galaxy |
| R.A. Position | 04h 7m 48.42s |
| Dec. Position | -12° 11' 36.66" |
| Constellation | Eridanus |
| Distance | 7billion-8 billion light-years (~2 billion parsecs) |
| About The Data | |
| Data Description | The Hubble spectrum was created from data from proposal : K. Noll (STScI) and J. Green, C. Froning, and B. Keeney (University of Colorado, Boulder). The DSS image is courtesy of the Digitized Sky Survey, STScI/AURA, Palomar/Caltech, and the UKSTU/AAO. Acknowledgments for PKS 0405-123 Observers: K. Noll (STScI) and J. Green, C. Froning, and B. Keeney (University of Colorado, Boulder) Data Analysis: 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) Science Consultants: M. Livio (STScI) and C. Froning and J. Green (University of Colorado, Boulder) |
| Instrument | HST>COS/FUV (spectra) and DSS>Anglo-Australian Observatory: UK Schmidt |
| Exposure Dates | August 3, 2009, Exposure Time: 2.7 hours (COS), and November 6, 1983 and January 10, 1986, Exposure Time: 2.2 hours (DSS) |
| Filters | DSS: OG590 and GG395 COS: G130M (130nm) |
| About The Image | |
| Color Info | DSS Image Red: OG590 Blue: GG395 |
| 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. |
