Editing Formaldehyde (section)

===Interstellar formaldehyde===
{{Main|Interstellar formaldehyde}}
Formaldehyde appears to be a useful probe in astrochemistry due to prominence of the 1<sub>10</sub>←1<sub>11</sub> and 2<sub>11</sub>←2<sub>12</sub> ''K''-doublet transitions. It was the first polyatomic [[Organic chemistry|organic]] molecule detected in the [[interstellar medium]].<ref>{{cite journal|last1=Zuckerman|first1=B.|last2=Buhl|first2=D.|last3=Palmer|first3=P.|last4=Snyder|first4=L. E.|year=1970|title=Observation of interstellar formaldehyde|journal=Astrophys. J.|volume=160|pages=485–506|doi=10.1086/150449|bibcode=1970ApJ...160..485Z}}</ref> Since its initial detection in 1969, it has been observed in many regions of the [[Milky Way galaxy|galaxy]]. Because of the widespread interest in interstellar formaldehyde, it has been extensively studied, yielding new extragalactic sources.<ref name="mangum">{{cite journal|first1=Jeffrey G.|last1=Mangum|first2=Jeremy|last2=Darling|first3=Karl M.|last3=Menten|first4=Christian|last4=Henkel|s2cid=14035123|year=2008|title=Formaldehyde Densitometry of Starburst Galaxies|journal=Astrophys. J.|volume=673|issue=2|pages=832–46|doi=10.1086/524354|bibcode=2008ApJ...673..832M |arxiv = 0710.2115}}</ref> A proposed mechanism for the formation is the hydrogenation of CO ice:<ref name="Woon">{{cite journal|last=Woon|first=David E.|year=2002|title=Modeling Gas-Grain Chemistry with Quantum Chemical Cluster Calculations. I. Heterogeneous Hydrogenation of CO and H<sub>2</sub>CO on Icy Grain Mantles|journal=Astrophys. J.|volume=569|issue=1|pages=541–48|doi=10.1086/339279|bibcode=2002ApJ...569..541W |doi-access=free}}</ref>
: H + CO → HCO
: HCO + H → CH<sub>2</sub>O

[[Hydrogen cyanide|HCN]], [[Hydrogen isocyanide|HNC]], H<sub>2</sub>CO, and [[dust]] have also been observed inside the [[Coma (cometary)|comae]] of [[comet]]s [[C/2012 F6 (Lemmon)]] and [[Comet ISON|C/2012 S1 (ISON)]].<ref name="NASA-20140811">{{cite web |last1=Zubritsky |first1=Elizabeth |last2=Neal-Jones |first2=Nancy |title=RELEASE 14-038 - NASA's 3-D Study of Comets Reveals Chemical Factory at Work |url=http://www.nasa.gov/press/2014/august/goddard/nasa-s-3-d-study-of-comets-reveals-chemical-factory-at-work |date=11 August 2014 |work=[[NASA]] |access-date=12 August 2014 |archive-date=12 August 2014 |archive-url=https://web.archive.org/web/20140812210755/http://www.nasa.gov/press/2014/august/goddard/nasa-s-3-d-study-of-comets-reveals-chemical-factory-at-work |url-status=live}}</ref><ref name="AJL-20140811">{{cite journal |author=Cordiner, M.A. |s2cid=26277035 |title=Mapping the Release of Volatiles in the Inner Comae of Comets C/2012 F6 (Lemmon) and C/2012 S1 (ISON) Using the Atacama Large Millimeter/Submillimeter Array |date=11 August 2014 |journal=[[The Astrophysical Journal]] |volume=792 |number=1 |doi=10.1088/2041-8205/792/1/L2 |display-authors=etal |pages=L2 |bibcode=2014ApJ...792L...2C|arxiv=1408.2458}}</ref>