Near Infrared Camera and Multi-Object Spectrometer: Difference between revisions

Revision as of 08:16, 7 August 2023

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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.

<blockquote>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.<ref>{{cite journal |title=The Performance of HST as an Infrared Telescope |last1=Robberto|first1= M.|display-authors= 4|last2= Sivaramakrishnan|first2= A.|last3= Bacinski|first3= J.J.|last4= Calzetti|first4= D.|author4-link= Daniela Calzetti |last5= Krist|first5= J.E.|last6= MacKenty|first6= J.W.|last7= Piquero|first7= J. |last8= Stiavelli|first8= M. |editor-first1=James B. |editor-first2=Peter |editor-last1=Breckinridge |editor-last2=Jakobsen |url=http://www.stsci.edu/hst/wfc3/documents/published/spie4013386.pdf |journal=Proc. SPIE |volume=4013 |pages=386–393 |date=2000 |doi=10.1117/12.394037 |series=UV, Optical, and IR Space Telescopes and Instruments|bibcode=2000SPIE.4013..386R|s2cid=14992130}}</ref></blockquote>

Despite this, the combination of Hubble's mirror and NICMOS offered never-before seen levels of quality in near-infrared performance at that time.<ref name="spaceflightnow.com">{{Cite web | url=http://www.spaceflightnow.com/news/n0206/06nicmos/ | title=Spaceflight Now &#124; Breaking News &#124; Hubble's infrared camera brought back to life}}</ref> Dedicated infrared telescopes like the [[Infrared Space Observatory]] 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.