The Near Infrared Camera and Multi-Object Spectrometer (NICMOS) is a

scientific instrument A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, an ...

for

infrared astronomy Infrared astronomy is a sub-discipline of astronomy which specializes in the observation and analysis of astronomical objects using infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers, and falls in betw ...

, installed on the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most vers ...

(HST), operating from 1997 to 1999, and from 2002 to 2008. Images produced by NICMOS contain data from the near-infrared part of the light spectrum. NICMOS was conceived and designed by the NICMOS Instrument Definition Team centered at

Steward Observatory Steward Observatory is the research arm of the Department of Astronomy at the University of Arizona (UArizona). Its offices are located on the UArizona campus in Tucson, Arizona (US). Established in 1916, the first telescope and building were f ...

University of Arizona The University of Arizona (Arizona, U of A, UArizona, or UA) is a public land-grant research university in Tucson, Arizona. Founded in 1885 by the 13th Arizona Territorial Legislature, it was the first university in the Arizona Territory. T ...

, USA. NICMOS is an imager and spectrometer built by Ball Aerospace & Technologies Corp. that allows the HST to observe

infrared light Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from arou ...

, with

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, t ...

s between 0.8 and 2.4 micrometers, providing imaging and slitless spectrophotometric capabilities. NICMOS contains three near-infrared detectors in three optical channels providing high (~ 0.1 arcsecond) resolution, coronagraphic and polarimetric imaging, and slitless spectroscopy in 11-, 19-, and 52-arcsecond square fields of view. Each optical channel contains a 256×256 pixel photodiode array of

mercury cadmium telluride Hg1−xCdxTe or mercury cadmium telluride (also cadmium mercury telluride, MCT, MerCad Telluride, MerCadTel, MerCaT or CMT) is a chemical compound of cadmium telluride (CdTe) and mercury telluride (HgTe) with a tunable bandgap spanning the shortwav ...

infrared detector An infrared detector is a detector that reacts to infrared (IR) radiation. The two main types of detectors are thermal and photonic (photodetectors). The thermal effects of the incident IR radiation can be followed through many temperature depen ...

s bonded to a sapphire substrate, read out in four independent 128×128 quadrants. NICMOS last worked in 2008, and has been largely replaced by the infrared channel of

Wide Field Camera 3 The Wide Field Camera 3 (WFC3) is the Hubble Space Telescope's last and most technologically advanced instrument to take images in the visible spectrum. It was installed as a replacement for the Wide Field and Planetary Camera 2 during the first ...

after its installation in 2009.

Limitations

The infrared performance of the Hubble has limitations since it was not designed with infrared performance as an objective. For example, the mirror is kept at a stable and relatively high temperature (15 °C) by heaters.

HST is a warm telescope. The IR background flux collected by cooled focal plane IR instruments like NICMOS or WFC3 is dominated, at rather short wavelengths, by telescope thermal emission rather than by zodiacal scattering. NICMOS data show that the telescope background exceeds the zodiacal background at wavelengths longer than λ ≈ 1.6μm, the exact value depending on the pointing on the sky and on the position of the Earth on its orbit.

Despite this, the combination of Hubble's mirror and NICMOS offered never-before seen levels of quality in near-infrared performance at that time. Dedicated infrared telescopes like the

Infrared Space Observatory The Infrared Space Observatory (ISO) was a space telescope for infrared light designed and operated by the European Space Agency (ESA), in cooperation with ISAS (now part of JAXA) and NASA. The ISO was designed to study infrared light at wavelengt ...

were ground-breaking in their own way, but had a smaller primary mirror, and were also out of service at the time of NICMOS installation because they ran out of coolant. NICMOS later overcame this problem by using a machine chiller like a refrigerator, which allowed it operate for years until it went offline in 2008.

History of NICMOS

NICMOS was installed on Hubble during its second servicing mission in 1997 (

STS-82 STS-82 was the 22nd flight of the Space Shuttle ''Discovery'' and the 82nd mission of the Space Shuttle program. It was NASA's second mission to service the Hubble Space Telescope, during which ''Discovery's'' crew repaired and upgraded the tel ...

) along with the

Space Telescope Imaging Spectrograph The Space Telescope Imaging Spectrograph (STIS) is a spectrograph, also with a camera mode, installed on the Hubble Space Telescope. Aerospace engineer Bruce Woodgate of the Goddard Space Flight Center was the principal investigator and crea ...

, replacing two earlier instruments. NICMOS in turn has been largely superseded by the

, which has a much larger field of view (135 by 127 arcsec, or 2.3 by 2.1 arcminutes), and reaches almost as far into the infrared. STS-82 crew

When conducting infrared measurements, it is necessary to keep the infrared detectors cooled to avoid having infrared interference from the instrument's own thermal emissions. NICMOS contains a cryogenic dewar, that cooled its detectors to about 61 K, and optical filters to ~ 105 K, with a block of

solid nitrogen Solid nitrogen is a number of solid forms of the element nitrogen, first observed in 1884. Solid nitrogen is mainly the subject of academic research, but low-temperature, low-pressure solid nitrogen is a substantial component of bodies in the ou ...

ice. When NICMOS was installed in 1997, the

dewar flask A vacuum flask (also known as a Dewar flask, Dewar bottle or thermos) is an insulating storage vessel that greatly lengthens the time over which its contents remain hotter or cooler than the flask's surroundings. Invented by Sir James Dew ...

contained a 230-pound (104 kg) block of nitrogen ice. Due to a thermal short that arose on March 4, 1997, during the instrument commissioning, the dewar ran out of

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

coolant sooner than expected in January 1999. During Hubble Service Mission 3B in 2002 (

STS-109 STS-109 (SM3B) was a Space Shuttle mission that launched from the Kennedy Space Center on 1 March 2002. It was the 108th mission of the Space Shuttle program, the 27th flight of the orbiter '' Columbia'' and the fourth servicing of the Hubble ...

), a replacement cooling system comprising a

cryocooler A refrigerator designed to reach cryogenic temperatures (below ) is often called a cryocooler. The term is most often used for smaller systems, typically table-top size, with input powers less than about 20 kW. Some can have input powers as l ...

, cryogenic circulator, and external radiator was installed on the Hubble that now cools NICMOS through a cryogenic neon loop. The NICMOS Cooling System (NCS) was developed on a very accelerated schedule (14 months vs. 5–10 years for other Hubble instrument hardware). NICMOS was returned to service soon after SM 3B. A new software upload in September 2008 necessitated a brief shutdown of the NICMOS cooling system. Several attempts to restart the cooling system were unsuccessful due to issues with the cryogenic circulator. After waiting more than six weeks for parts of the instrument to warm up, and theorized ice particles to sublimate from the neon circulating loop, the cooler once again failed to restart. An Anomaly Review Board (ARB) was then convened by NASA. The ARB concluded that ice or other solid particle migrated from the dewar to the circulator during the September 2008 restart attempt and that the circulator may be damaged, and determined an alternative set of startup parameters. A successful restart at 13:30 EST on 16 December 2008 led to four days of cooler operations followed by another shutdown. On 1 August 2009, the cooler was restarted again; NICMOS was expected to resume operations in mid-February 2010 and operated through October 22, 2009, at which point a lock-up of Hubble's data handling system caused the telescope to shut down. The circulation flow rate to NICMOS was greatly reduced during this operating period confirming blockage in the circulation loop. Continued operation at reduced flow rates would limit NICMOS science so plans for purging and refilling the circulation system with clean neon gas were developed by NASA. The circulation loop is equipped with an extra neon tank and remotely operated solenoid valves for on-orbit purge-fill operations. As of 2013, these purge-fill operations have not yet been performed. WFC3, installed 2009, was designed to partly replace NICMOS. On June 18, 2010, it was announced NICMOS would not be available for science during the latest proposal Cycle 18. As of 2013, a decision as to whether the purge-fill operations will be performed and whether NICMOS will be available for science in the future has not been made. NICMOS is also the name of the device's 256×256-pixel imaging sensor built by Rockwell International Electro-Optical Center (now DRS Technologies).

Scientific results

NICMOS was noted for its performance in Near-infrared space astronomy, in particular its ability to see objects through dust. It was used for about 23 months after it was installed, its life limited by set amount of cryo-coolant, and then later it was used for several years when a new cryo-cooler was installed in 2002. NICMOS combined near infrared performance with a large mirror. NICMOS allowed investigation of high redshift galaxies and quasars with high spatial resolution, which was especially useful when analyzed in conjunction with other instruments such as the STIS, and it also allowed deeper investigation of stellar populations. In planetary science, NICMOS was used to discover an impact basin on the south pole of the asteroid

4 Vesta Vesta ( minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta, t ...

. (4 Vesta was later visited by

Dawn (spacecraft) ''Dawn'' is a retired space probe that was launched by NASA in September 2007 with the mission of studying two of the three known protoplanets of the asteroid belt: Vesta and Ceres. In the fulfillment of that mission—the ninth in NASA's Di ...

in the 2010s which investigated it more closely by orbiting it.) In 2009, an old NICMOS image was processed to show a predicted exoplanet around the star

HR 8799 HR 8799 is a roughly 30 million-year-old main-sequence star located away from Earth in the constellation of Pegasus. It has roughly 1.5 times the Sun's mass and 4.9 times its luminosity. It is part of a system that also ...

. The system is thought to be about 130

light-years A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

from Earth. In 2011, around that same star, four exoplanets were rendered viewable in a NICMOS image taken in 1998, using advanced data processing.NASA - Astronomers Find Elusive Planets in Decade-Old Hubble Data - 10.06.11
/ref> The exoplanets were originally discovered with the Keck telescopes and the Gemini North telescope between 2007 and 2010. The image allows the orbits of the exoplanets to be analyzed more closely, since they take many decades, even hundreds of Earth years, to orbit their host star. NICMOS observed the exoplanet

XO-2b XO-2Nb (or rarely XO-2Bb) is an extrasolar planet orbiting the star XO-2N, the fainter component of XO-2 wide binary star in the constellation Lynx. This planet was found by the transit method in 2007 by Burke et al. This was the second such plane ...

at star XO-2, and a spectroscopy result was obtained for this exoplanet in 2012. This uses the spectroscopic abilities of the instrument, and in astronomy spectroscopy during a planetary transit (an exoplanet passes in front of star from the perspective of Earth) is a way to study that exoplanet's possible atmosphere. In 2014, researchers recovered planetary discs in old NICMOS data using new image processing techniques.

Shuttle missions

*STS-82, (year:1997) installed, NICMOS replaces GHRS *STS-109, (year:2002) new crycooler installed, returned to operation.

References

External links

NICMOS at ESA/HubbleImages taken with NICMOS at ESA/Hubble
from