School of Physics and Astronomy

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Dr Catherine Walsh

Astrophysics Group

Contact details

Room: 9.63
Tel: +44 (0)113 3430958
Email: c.walsh1 @


Molecular astrophysics
Star and planet formation
Protoplanetary disks
Exoplanetary atmospheres
Submillimeter astronomy

Research interests

I study molecules in space across the spectrum of molecular sources: from interstellar clouds, the birth places of stars, through to protoplanetary disks and planetary atmospheres, and even on to circumstellar envelopes around dying stars. Molecules have huge prebiotic significance since they are the elementary building blocks of planetary systems. I am interested in fundamental astrochemical processes, i.e., how molecules are formed and destroyed in different environments, and how they can be used to probe the physical conditions in the diverse range of extreme environments in which they survive. Molecules are a unique and powerful tool in astronomy.

I make use of high-spatial and high-spectral resolution observations with the Atacama Large Millimeter/Submillimeter Array which is currently revolutionising the field of star and planet formation. I am principal investigator of four ALMA programs, two of which concern the investigation of the gas and dust structure of protoplanetary disks around intermediate-mass stars that also show signatures of embedded planets and ongoing planet formation. The second two programs are a deep search for the complex organic ice reservoir in disks around nearby Sun-like stars, to help answer questions regarding the origin of complex molecules in planetary systems.

Useful links

Kinetic Database for Astrochemistry (KIDA)
The UMIST Database for Astrochemistry (UDfA)
The Extrasolar Planets Encyclopaedia
NIST Chemical Kinetics Database
Photodissociation and photoionization of astrophysically relevant
PHotoIonization/Dissociation RATES (Huebner database)
The Cologne Database for Molecular Spectroscopy (CDMS)
JPL Molecular Spectroscopy
Leiden Atomic and Molecular Database (LAMDA)
NIST Chemistry Web Book
NIST-JANAF Thermochemical Tables
Computational Chemistry Comparison and Benchmark DataBase


Palau A, Walsh C, Sánchez-Monge Á, Girart JM, Cesaroni R, Jiménez-Serra I, Fuente A, Zapata LA, Neri R Complex Organic Molecules tracing shocks along the outflow cavity in the high-mass protostar IRAS 20126+4104 Monthly Notices of the Royal Astronomical Society 467 2723-2752, 2017
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van 't Hoff MLR, Walsh C, Kama M, Facchini S, van Dishoeck EF Robustness of N₂H⁺ as tracer of the CO snowline Astronomy&Astrophysics 599 -, 2017
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Furuya K, Drozdovskaya MN, Visser R, van Dishoeck EF, Walsh C, Harsono D, Hincelin U, Taquet V Water delivery from cores to disks: Deuteration as a probe of the prestellar inheritance of H₂O Astronomy&Astrophysics 599 -, 2017
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Notsu S, Nomura H, Ishimoto D, Walsh C, Honda M, Hirota T, Millar TJ Candidate Water Vapor Lines to Locate the H2O Snowline Through High-dispersion Spectroscopic Observations. II. the Case of a Herbig Ae Star Astrophysical Journal 836 -, 2017
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Millar TJ, Walsh C, Field TA Negative Ions in Space Chemical Reviews 117 1765-1795, 2017
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Cuppen HM, Walsh C, Lamberts T, Semenov D, Garrod RT, Penteado EM, Ioppolo S Grain Surface Models and Data for Astrochemistry Space Science Reviews 1-58, 2017
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Taquet V, Furuya K, Walsh C, Van Dishoeck EF A primordial origin for molecular oxygen in comets: a chemical kinetics study of the formation and survival of O₂ ice from clouds to discs Monthly Notices of the Royal Astronomical Society 462 S99-S115, 2016
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Walsh C, Juhász A, Meeus G, Dent WRF, Maud LT, Aikawa Y, Millar TJ, Nomura H ALMA reveals the anatomy of the mm-sized dust and molecular gas in the HD 97048 disk Astrophysical Journal 831 -, 2016
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Eistrup C, Walsh C, Van Dishoeck EF Setting the volatile composition of (exo)planet-building material. Does chemical evolution in disk midplanes matter? Astronomy&Astrophysics 595 -, 2016
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Drozdovskaya MN, Walsh C, Van Dishoeck EF, Furuya K, Marboeuf U, Thiabaud A, Harsono D, Visser R Cometary ices in forming protoplanetary disc midplanes Monthly Notices of the Royal Astronomical Society 462 977-993, 2016
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Tsukagoshi T, Nomura H, Muto T, Kawabe R, Ishimoto D, Kanagawa KD, Okuzumi S, Ida S, Walsh C, Millar TJ A Gap with a Deficit of Large Grains in the Protoplanetary Disk around TW Hya Astrophysical Journal Letters 829 -, 2016
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Haworth TJ, Ilee JD, Forgan DH, Facchini S, Price DJ, Boneberg DM, Booth RA, Clarke CJ, Gonzalez JF, Hutchison MA, Kamp I, Laibe G, Lyra W, Meru F, Mohanty S, Panić O, Rice K, Suzuki T, Teague R, Walsh C, Woitke P Grand Challenges in Protoplanetary Disc Modelling Publications of the Astronomical Society of Australia 33 -, 2016
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Notsu S, Nomura H, Ishimoto D, Walsh C, Honda M, Hirota T, Millar TJ Candidate Water Vapor Lines to Locate the H₂O Snowline through High-dispersion Spectroscopic Observations. I. The Case of a T Tauri Star The Astrophysical Journal 827 -, 2016
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Decin L, Richards AMS, Millar TJ, Baudry A, De Beck E, Homan W, Smith N, Van de Sande M, Walsh C ALMA-resolved salt emission traces the chemical footprint and inner wind morphology of VY Canis Majoris Astronomy&Astrophysics 592 -, 2016
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Walsh C, Loomis RA,Öberg KI, Kama M, Van ’t Hoff MLR, Millar TJ, Aikawa Y, Herbst E, Widicus Weaver SL, Nomura H First Detection of Gas-phase Methanol in a Protoplanetary Disk The Astrophysical Journal 823 -, 2016
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Li X, Millar TJ, Heays AN, Walsh C, van Dishoeck EF, Cherchneff I Chemistry and distribution of daughter species in the circumstellar envelopes of O-rich AGB stars Astronomy&Astrophysics 588 A4-A4, 2016

Nomura H, Tsukagoshi T, Kawabe R, Ishimoto D, Okuzumi S, Muto T, Kanagawa KD, Ida S, Walsh C, Millar TJ, Bai X-N ALMA Observations of a Gap and a Ring in the Protoplanetary Disk around TW Hya The Astrophysical Journal 819 -, 2016
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Bieler A, Altwegg K, Balsiger H, Bar-Nun A, Berthelier J-J, Bochsler P, Briois C, Calmonte U, Combi M, De Keyser J, van Dishoeck EF, Fiethe B, Fuselier SA, Gasc S, Gombosi TI, Hansen KC, Hässig M, Jäckel A, Kopp E, Korth A, Le Roy L, Mall U, Maggiolo R, Marty B, Mousis O, Owen T, Rème H, Rubin M, Sémon T, Tzou C-Y, Waite JH, Walsh C, Wurz P Abundant molecular oxygen in the coma of comet 67P/Churyumov–Gerasimenko Nature 526 678-681, 2015

Wright CM, Maddison ST, Wilner DJ, Burton MG, Lommen D, Van Dishoeck EF, Pinilla P, Bourke TL, Menard F, Walsh C Resolving structure of the disc around HD100546 at 7 mm with ATCA Monthly Notices of the Royal Astronomical Society 453 414-438, 2015
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Walsh C, Nomura H, Van Dishoeck E The molecular composition of the planet-forming regions of protoplanetary disks across the luminosity regime Astronomy&Astrophysics 582 -, 2015
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Drozdovskaya MN, Walsh C, Visser R, Harsono D, Van Dishoeck EF The complex chemistry of outflow cavity walls exposed: the case of low-mass protostars Monthly Notices of the Royal Astronomical Society 451 3836-3856, 2015
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Pinilla P, Birnstiel T, Walsh C Sequential planet formation in the HD 100546 protoplanetary disk? Astronomy&Astrophysics 580 -, 2015
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Murillo NM, Bruderer S, Van Dishoeck EF, Walsh C, Harsono D, Lai S-P, Fuchs CM A low-mass protostar’s disk-envelope interface: disk-shadowing evidence from ALMA DCO⁺ observations of VLA1623 Astronomy&Astrophysics 579 -, 2015
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Arasa C, Koning J, Kroes G-J, Walsh C, Van Dishoeck EF Photodesorption of H2O, HDO, and D2O ice and its impact on fractionation Astronomy&Astrophysics 575 -, 2015
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Walsh C Chemical complexity in protoplanetary disks in the era of ALMA and Rosetta, 2015
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Schmalzl M, Visser R, Walsh C, Albertsson T, Van Dishoeck EF, Kristensen LE, Mottram JC Water in low-mass star-forming regions with Herschel Astronomy&Astrophysics 572 -, 2014
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Drozdovskaya MN, Walsh C, Visser R, Harsono D, Van Dishoeck EF Methanol along the path from envelope to protoplanetary disc Monthly Notices of the Royal Astronomical Society 445 913-929, 2014
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Walsh C, Juhász A, Pinilla P, Harsono D, Mathews GS, Dent WRF, Hogerheijde MR, Birnstiel T, Meeus G, Nomura H, Aikawa Y, Millar TJ, Sandell G ALMA Hints at the Presence of two Companions in the Disk around HD 100546 Astrophysical Journal Letters 791 -, 2014
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Li X, Millar TJ, Walsh C, Heays AN, Van Dishoeck EF Photodissociation and chemistry of N 2 in the circumstellar envelope of carbon-rich AGB stars Astronomy&Astrophysics 568 -, 2014
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Walsh C, Herbst E, Nomura H, Millar TJ, Weaver SW Complex organic molecules along the accretion flow in isolated and externally irradiated protoplanetary disks Faraday Discussions 168 389-421, 2014
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Walsh C, Millar TJ, Nomura H, Herbst E, Weaver SW, Aikawa Y, Laas JC, Vasyunin AI Complex organic molecules in protoplanetary disks Astronomy&Astrophysics 563 -, 2014
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Thrower JD, Ioppolo S, Walsh C Highlights from Faraday Discussion 168: Astrochemistry of Dust, Ice and Gas, Leiden, The Netherlands, April 2014 Chem. Commun. 50 13636-13644, 2014

Walsh C, Millar TJ, Nomura H Molecular Line Emission from a Protoplanetary Disk Irradiated Externally by a Nearby Massive Star The Astrophysical Journal Letters 766 L23-L23, 2013
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McElroy D, Walsh C, Markwick AJ, Cordiner MA, Smith K, Millar TJ The UMIST database for astrochemistry 2012 Astronomy&Astrophysics 550 A36-A36, 2013

Woods PM, Walsh C, Cordiner MA, Kemper F The chemistry of extragalactic carbon stars Monthly Notices of the Royal Astronomical Society 426 2689-2702, 2012

Walsh C, Nomura H, Millar TJ, Aikawa Y Chemical Processes in Protoplanetary Disks. II. On the Importance of Photochemistry and X-Ray Ionization The Astrophysical Journal 747 114-114, 2012
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Suutarinen A, Geppert WD, Harju J, Heikkilä A, Hotzel S, Juvela M, Millar TJ, Walsh C, Wouterloot JGA CH abundance gradient in TMC-1 Astronomy&Astrophysics 531 A121-A121, 2011

Heinzeller D, Nomura H, Walsh C, Millar TJ Chemical Evolution of Protoplanetary Disks—The Effects of Viscous Accretion, Turbulent Mixing, and Disk Winds The Astrophysical Journal 731 115-115, 2011
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Cordiner MA, Charnley SB, Buckle JV, Walsh C, Millar TJ Discovery of Interstellar Anions in Cepheus and Auriga The Astrophysical Journal Letters 730 L18-L23, 2011
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Walsh C, Millar TJ, Nomura H Chemical Processes in Protoplanetary Disks The Astrophysical Journal 722 1607-1623, 2010
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Vigren E, Hamberg M, Zhaunerchyk V, Kaminska M, Semaniak J, Larsson M, Thomas RD, af Ugglas M, Kashperka I, Millar TJ, Walsh C, Roberts H, Geppert WD Dissociative Recombination of Protonated Formic Acid: Implications for Molecular Cloud and Cometary Chemistry The Astrophysical Journal 709 1429-1435, 2010
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Vigren E, Hamberg M, Zhaunerchyk V, Kaminska M, Thomas RD, Trippel S, Zhang M, Kashperka I, Ugglas MA, Walsh C, Wester R, Semaniak J, Larsson M, Geppert WD Dissociative recombination of the acetaldehyde cation, CH3CHO+ Physical Chemistry Chemical Physics 12 11670-11670, 2010

Walsh C, Harada N, Herbst E, Millar TJ The Effects of Molecular Anions on the Chemistry of Dark Clouds The Astrophysical Journal 700 752-761, 2009
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Vigren E, Hamberg M, Zhaunerchyk V, Kamińska M, Thomas RD, Larsson M, Millar TJ, Walsh C, Geppert WD The Dissociative Recombination of Protonated Acrylonitrile, CH2CHCNH+, with Implications for the Nitrile Chemistry in Dark Molecular Clouds and the Upper Atmosphere of Titan The Astrophysical Journal 695 317-324, 2009
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Kamińska M, Vigren E, Zhaunerchyk V, Geppert WD, Roberts H, Walsh C, Millar TJ, Danielsson M, Hamberg M, Thomas RD, Larsson M, af Ugglas M, Semaniak J Dissociative Recombination of D3S+: Product Branching Fractions and Absolute Cross Sections The Astrophysical Journal 681 1717-1724, 2008
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Millar TJ, Walsh C, Cordiner MA, Ni Chuimin R, Herbst E Hydrocarbon Anions in Interstellar Clouds and Circumstellar Envelopes The Astrophysical Journal Letters 662 L87-L90, 2007
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