Hubble Ultra-Deep Field
The Hubble Ultra-Deep Field (HUDF) is a
The HUDF image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. Located southwest of
In August and September 2009, the HUDF field was observed at longer wavelengths (1.0 to 1.6 µm) using the infrared channel of the recently fitted Wide Field Camera 3 (WFC3). This additional data enabled astronomers to identify a new list of potentially very distant galaxies.[4][5]
On September 25, 2012, NASA released a new version of the Ultra-Deep Field dubbed the eXtreme Deep Field (XDF). The XDF reveals galaxies from 13.2 billion years ago, including one thought to have formed only 450 million years after the Big Bang.[6]
On June 3, 2014, NASA released the Hubble Ultra Deep Field 2014 image, the first HUDF image to use the full range of
On January 23, 2019, the Instituto de Astrofísica de Canarias released an even deeper version[9] of the infrared images of the Hubble Ultra Deep Field obtained with the WFC3 instrument, named the ABYSS Hubble Ultra Deep Field. The new images improve the previous reduction of the WFC3/IR images, including careful sky background subtraction around the largest galaxies on the field of view. After this update, some galaxies were found to be almost twice as big as previously measured.[10][11]
Planning
In the years since the original
Unlike the Deep Fields, the HUDF does not lie in Hubble's Continuous Viewing Zone (CVZ). The earlier observations, using the
As with the earlier fields, this one was required to contain very little emission from our galaxy, with little
Observations
Four filters were used on the ACS, centered on 435, 606, 775 and 850 nm, with
The observations were done in two sessions, from September 23 to October 28, 2003, and December 4, 2003, to January 15, 2004. The total exposure time is just under 1 million seconds, from 400 orbits, with a typical exposure time of 1200 seconds.[12] In total, 800 ACS exposures were taken over the course of 11.3 days, two per orbit; NICMOS observed for 4.5 days. All the individual ACS exposures were processed and combined by Anton Koekemoer into a set of scientifically useful images, each with a total exposure time ranging from 134,900 seconds to 347,100 seconds. To observe the whole sky to the same sensitivity, the HST would need to observe continuously for a million years.[1]
Camera | Filter | Wavelength | Total exposure time | Exposures |
---|---|---|---|---|
ACS | F435W | 435 nm | 134,880 s (56 orbits) | 112 |
ACS | F606W | 606 nm | 135,320 s (56 orbits) | 112 |
ACS | F775W | 775 nm | 347,110 s (144 orbits) | 288 |
ACS | F850LP | 850 nm | 346,620 s (144 orbits) | 288 |
The sensitivity of the ACS limits its capability of detecting galaxies at high redshift to about 6. The deep NICMOS fields obtained in parallel to the ACS images could in principle be used to detect galaxies at redshift 7 or higher but they were lacking visible band images of similar depth. These are necessary to identify high redshift objects as they should not be seen in the visible bands. In order to obtain deep visible exposures on top of the NICMOS parallel fields a follow-up program, HUDF05, was approved and granted 204 orbits to observe the two parallel fields (GO-10632).[14] The orientation of the HST was chosen so that further NICMOS parallel images would fall on top of the main UDF field.
After the installation of
Camera | Filter | Wavelength | Exposure time |
---|---|---|---|
WFC3 | F105W | 1050 nm ± 150 | 16 orbits, 14 usable |
WFC3 | F125W | 1250 nm ± 150 | 16 orbits |
WFC3 | F160W | 1600 nm ± 150 | 28 orbits |
Contents
The HUDF is the deepest image of the
The field imaged by the ACS contains over 10,000 objects, the majority of which are galaxies, many at redshifts greater than 3, and some that probably have redshifts between 6 and 7.[12] The NICMOS measurements may have discovered galaxies at redshifts up to 12.[1]
Scientific results
The HUDF has revealed high rates of
Hubble eXtreme Deep Field
The Hubble eXtreme Deep Field (HXDF), released on September 25, 2012, is an image of a portion of space in the center of the Hubble Ultra Deep Field image. Representing a total of two million seconds (about 23 days) of exposure time collected over 10 years, the image covers an area of 2.3 arcminutes by 2 arcminutes,[18] or about 80% of the area of the HUDF. This represents about one thirty-two millionth of the sky.
The HXDF contains about 5,500 galaxies, the oldest of which are seen as they were 13.2 billion years ago. The faintest galaxies are one ten-billionth the brightness of what the human eye can see. The red galaxies in the image are the remnants of galaxies after major collisions during their elderly years. Many of the smaller galaxies in the image are very young galaxies that eventually developed into major galaxies, similar to the Milky Way and other galaxies in our galactic neighborhood.[6]
-
XDF size compared with the size of the Moon
-
HXDF image shows mature galaxies in the foreground plane, nearly mature galaxies from 5 to 9 billion years ago, and protogalaxies beyond 9 billion years.
-
Video (02:42) about how the Hubble eXtreme Deep Field image was made.
See also
- List of deep fields
- List of UDF objects (1–500)
- HUDF-JD2
- UDF 2457 (star)
- UDFj-39546284
- UDFy-38135539
References
- ^ a b c d e "Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies" (Press release). NASA. March 9, 2004. Retrieved March 9, 2024.
- ^ "HubbleSite: Categories - news". hubblesite.org. Archived from the original on 2016-11-11. Retrieved 2014-02-26.
- ^ "Moon Illusion". homepages.wmich.edu. Archived from the original on 2017-05-09. Retrieved 2014-02-26.
- ^ "HubbleSite: News - Hubble's Deepest View of Universe Unveils Never-Before-Seen Galaxies". hubblesite.org.
- ^ S2CID 118083736.
- ^ a b "Hubble Goes to the eXtreme to Assemble Farthest-Ever View of the Universe". NASA. September 25, 2012. Retrieved September 26, 2012.
- ^ "IAC PRESS RELEASE - Making the Hubble's deepest images even deeper". Instituto de Astrofísica de Canarias. January 24, 2019.
- ^ "Hubble Ultra Deep Field 2014". HubbleSite.org. Retrieved 2022-01-25.
- ^ "Instituto de Astrofísica de Canarias - IAC - Educational Outreach". www.iac.es. January 24, 2019. Retrieved February 5, 2019.
- S2CID 119232262.
- S2CID 119232262.
- ^ S2CID 119504137.
- S2CID 1176087.
- ^ "10632 Program Information".
- ^ "11563 Program Information".
- ^ Malhotra, Sangeeta. "As far as the Hubble can see" (PDF). Arizona State University. Retrieved October 28, 2010.
- ^ "Highlight HUDF Center at 3 32 39.0 -27 47 29.1". Wikisky. Retrieved October 28, 2010.
- ^ "Hubble Goes to the eXtreme to Assemble Farthest Ever View of the Universe". September 25, 2012. Archived from the original on October 6, 2013. Retrieved February 26, 2014.
External links
- NASA site with animations
- Exploring galaxy formation in the early universe - How did the first galaxies get so large so quickly?
- Scalable interactive UDF with 10,000 galaxies mapped. Wikisky.org
- Hubblesite page for the XDF image
- XDF Project from the UCO/Lick Observatory
- The Hubble Ultra-Deep Field in Light and Sound at APOD
- ABYSS Hubble Ultra Deep Field