Paul Barklem
Professor at Department of Physics and Astronomy; Astronomy and Space Physics
- Telephone:
- +46 18 471 59 81
- E-mail:
- paul.barklem@physics.uu.se
- Visiting address:
- Ångströmlaboratoriet, Regementsvägen 10
- Postal address:
- Box 516
751 37 UPPSALA
- ORCID:
- 0000-0003-2415-9836
Short presentation
Astrophysicist working on stellar atmospheres, supernova and kilonova ejectae, to understand stars and their environments, the evolution of the chemical elements, and the history of the Milky Way. My day to day work is on the theory and calculation of atomic and molecular processes, especially collision processes, and when possible test the calculations via experiments (usually at DESIREE).
I teach Classical Mechanics for Engineers, Theoretical Astrophysics, and Astrochemistry.
Biography
I was born in Melbourne, Australia, but grew up in Brisbane. I studied physics at the University of Queensland before coming to work at Uppsala University.
Research
I work on stellar spectroscopy, especially related atomic processes, and its applications to understanding the stars, the formation of the Milky Way, and the evolution of the elements. Here is a popular level article on what I do. If you want to know more I recommend the following review article. You can also find my other publications listed below or at NASA ADS. If you are interested in various data or codes my collaborators and I produce, see my github repository.

Publications
Recent publications
The solar beryllium abundance revisited with 3D non-LTE models
Part of Astronomy and Astrophysics, 2024
- DOI for The solar beryllium abundance revisited with 3D non-LTE models
- Download full text (pdf) of The solar beryllium abundance revisited with 3D non-LTE models
Revisiting the statistical equilibrium of H- in stellar atmospheres
Part of Astronomy and Astrophysics, 2024
- DOI for Revisiting the statistical equilibrium of H- in stellar atmospheres
- Download full text (pdf) of Revisiting the statistical equilibrium of H- in stellar atmospheres
State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2024
- DOI for State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
- Download full text (pdf) of State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
Part of Astronomy and Astrophysics, 2024
- DOI for 3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
- Download full text (pdf) of 3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
Part of Astronomy and Astrophysics, 2023
- DOI for The molecular chemistry of Type Ibc supernovae and diagnostic potential with the James Webb Space Telescope
- Download full text (pdf) of The molecular chemistry of Type Ibc supernovae and diagnostic potential with the James Webb Space Telescope
All publications
Articles in journal
The solar beryllium abundance revisited with 3D non-LTE models
Part of Astronomy and Astrophysics, 2024
- DOI for The solar beryllium abundance revisited with 3D non-LTE models
- Download full text (pdf) of The solar beryllium abundance revisited with 3D non-LTE models
Revisiting the statistical equilibrium of H- in stellar atmospheres
Part of Astronomy and Astrophysics, 2024
- DOI for Revisiting the statistical equilibrium of H- in stellar atmospheres
- Download full text (pdf) of Revisiting the statistical equilibrium of H- in stellar atmospheres
State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2024
- DOI for State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
- Download full text (pdf) of State-resolved mutual neutralization of 16O+ with 1H− and 2H− at collision energies below 100 meV
3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
Part of Astronomy and Astrophysics, 2024
- DOI for 3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
- Download full text (pdf) of 3D NLTE modelling of Y and Eu: Centre-to-limb variation and solar abundances
Part of Astronomy and Astrophysics, 2023
- DOI for The molecular chemistry of Type Ibc supernovae and diagnostic potential with the James Webb Space Telescope
- Download full text (pdf) of The molecular chemistry of Type Ibc supernovae and diagnostic potential with the James Webb Space Telescope
Observation of an isotope effect in state-selective mutual neutralization of lithium with hydrogen
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2023
- DOI for Observation of an isotope effect in state-selective mutual neutralization of lithium with hydrogen
- Download full text (pdf) of Observation of an isotope effect in state-selective mutual neutralization of lithium with hydrogen
Detailed alpha abundance trends in the inner Galactic bulge
Part of Astronomy and Astrophysics, 2023
- DOI for Detailed alpha abundance trends in the inner Galactic bulge
- Download full text (pdf) of Detailed alpha abundance trends in the inner Galactic bulge
State-Resolved Mutual Neutralization of Mg+ and D-
Part of Physical Review Letters, 2022
- DOI for State-Resolved Mutual Neutralization of Mg+ and D-
- Download full text (pdf) of State-Resolved Mutual Neutralization of Mg+ and D-
Storage-ring study of the mutual neutralization of N plus with O minus
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2022
- DOI for Storage-ring study of the mutual neutralization of N plus with O minus
- Download full text (pdf) of Storage-ring study of the mutual neutralization of N plus with O minus
Part of Astronomy and Astrophysics, 2022
- DOI for Titanium abundances in late-type stars: I. 1D non-local thermodynamic equilibrium modelling in benchmark dwarfs and giants
- Download full text (pdf) of Titanium abundances in late-type stars: I. 1D non-local thermodynamic equilibrium modelling in benchmark dwarfs and giants
Part of Astronomy and Astrophysics, 2022
- DOI for The solar photospheric silicon abundance according to (COBOLD)-B-5: Investigating line broadening, magnetic fields, and model effects
- Download full text (pdf) of The solar photospheric silicon abundance according to (COBOLD)-B-5: Investigating line broadening, magnetic fields, and model effects
Part of Astronomy and Astrophysics, 2022
Part of Astronomy and Astrophysics, 2022
- DOI for The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products star
- Download full text (pdf) of The Gaia-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products star
Non-LTE abundance corrections for late-type stars from 2000Å to 3 μm
Part of Astronomy and Astrophysics, 2022
- DOI for Non-LTE abundance corrections for late-type stars from 2000Å to 3 μm
- Download full text (pdf) of Non-LTE abundance corrections for late-type stars from 2000Å to 3 μm
Final-state-resolved mutual neutralization of Na+ and D-
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2021
- DOI for Final-state-resolved mutual neutralization of Na+ and D-
- Download full text (pdf) of Final-state-resolved mutual neutralization of Na+ and D-
Atomic data for the Gaia-ESO Survey
Part of Astronomy and Astrophysics, 2021
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2021
- DOI for Correspondence between the surface integral and linear combination of atomic orbitals methods for ionic-covalent interactions in mutual neutralization processes involving H-/D-
- Download full text (pdf) of Correspondence between the surface integral and linear combination of atomic orbitals methods for ionic-covalent interactions in mutual neutralization processes involving H-/D-
Part of Astronomy and Astrophysics, 2021
Part of Physical Chemistry, Chemical Physics - PCCP, p. 24607-24616, 2021
- DOI for Mutual neutralisation of O+ with O-: investigation of the role of metastable ions in a combined experimental and theoretical study
- Download full text (pdf) of Mutual neutralisation of O+ with O-: investigation of the role of metastable ions in a combined experimental and theoretical study
Part of Astrophysical Journal, 2021
Part of Physical Review A: covering atomic, molecular, and optical physics and quantum information, 2020
- DOI for Cryogenic merged-ion-beam experiments in DESIREE: Final-state-resolved mutual neutralization of Li+ and D-
- Download full text (pdf) of Cryogenic merged-ion-beam experiments in DESIREE: Final-state-resolved mutual neutralization of Li+ and D-
Part of Astronomy and Astrophysics, 2020
The 3D non-LTE solar nitrogen abundance from atomic lines
Part of Astronomy and Astrophysics, 2020
4MOST: Project overview and information for the First Call for Proposals
Part of The Messenger, p. 3-11, 2019
Non-LTE analysis of K I in late-type stars
Part of Astronomy and Astrophysics, 2019
Part of Astronomy and Astrophysics, 2019
- DOI for Excitation and charge transfer in low-energy hydrogen atom collisions with neutral carbon and nitrogen
- Download full text (pdf) of Excitation and charge transfer in low-energy hydrogen atom collisions with neutral carbon and nitrogen
3D non-LTE line formation of neutral carbon in the Sun
Part of Astronomy and Astrophysics, 2019
- DOI for 3D non-LTE line formation of neutral carbon in the Sun
- Download full text (pdf) of 3D non-LTE line formation of neutral carbon in the Sun
Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram
Part of Astronomy and Astrophysics, 2019
Ca line formation in late-type stellar atmospheres: I. The model atom
Part of Astronomy and Astrophysics, 2019
Carbon and oxygen in metal-poor halo stars
Part of Astronomy and Astrophysics, 2019
Gaia Data Release 2 Kinematics of globular clusters and dwarf galaxies around the Milky Way
Part of Astronomy and Astrophysics, 2018
A New Test of Copper and Zinc Abundances in Late-type Stars Using Ultraviolet Cu II and Zn II Lines
Part of Astrophysical Journal, 2018
Effective temperature determinations of late-type stars based on 3D non-LTE Balmer line formation
Part of Astronomy and Astrophysics, 2018
A collection of model stellar spectra for spectral types B to early-M
Part of Astronomy and Astrophysics, 2018
Gaia Data Release 2: Observations of solar system objects
Part of Astronomy and Astrophysics, 2018
- DOI for Gaia Data Release 2: Observations of solar system objects
- Download full text (pdf) of Gaia Data Release 2: Observations of solar system objects
Gaia Data Release 2 The celestial reference frame (Gaia-CRF2)
Part of Astronomy and Astrophysics, 2018
Gaia Data Release 2 Summary of the contents and survey properties
Part of Astronomy and Astrophysics, 2018
Observational Hertzsprung-Russell diagrams
Part of Astronomy and Astrophysics, 2018
- DOI for Observational Hertzsprung-Russell diagrams
- Download full text (pdf) of Observational Hertzsprung-Russell diagrams
Chemical characterization of the inner Galactic bulge: North-South symmetry
Part of Monthly notices of the Royal Astronomical Society, p. 4374-4389, 2018
Gaia Data Release 2 Mapping the Milky Way disc kinematics
Part of Astronomy and Astrophysics, 2018
- DOI for Gaia Data Release 2 Mapping the Milky Way disc kinematics
- Download full text (pdf) of Gaia Data Release 2 Mapping the Milky Way disc kinematics
Inelastic O plus H collisions and the O I 777 nm solar centre-to-limb variation
Part of Astronomy and Astrophysics, 2018
Excitation and charge transfer in low-energy hydrogen atom collisions with neutral iron
Part of Astronomy and Astrophysics, 2018
Excitation and charge transfer in low-energy hydrogen atom collisions with neutral oxygen
Part of Astronomy and Astrophysics, 2018
Data on inelastic processes in low-energy potassium-hydrogen and rubidium-hydrogen collisions
Part of Monthly notices of the Royal Astronomical Society, p. 3810-3817, 2018
- DOI for Data on inelastic processes in low-energy potassium-hydrogen and rubidium-hydrogen collisions
- Download full text (pdf) of Data on inelastic processes in low-energy potassium-hydrogen and rubidium-hydrogen collisions
3D NLTE Analysis of the Most Iron-Deficient Star, SMSS0313-6708
Part of Astronomy and Astrophysics, 2017
The Hamburg/ESO R-process Enhanced Star survey (HERES)
Part of Astronomy and Astrophysics, 2017
Inelastic e plus Mg collision data and its impact on modelling stellar and supernova spectra
Part of Astronomy and Astrophysics, 2017
Part of Monthly notices of the Royal Astronomical Society, p. 4311-4322, 2017
- DOI for Non-LTE line formation of Fe in late-type stars - IV. Modelling of the solar centre-to-limb variation in 3D
- Download full text (pdf) of Non-LTE line formation of Fe in late-type stars - IV. Modelling of the solar centre-to-limb variation in 3D
Mg line formation in late-type stellar atmospheres: II. Calculations in a grid of 1D models
Part of Astronomy and Astrophysics, 2016
Non-LTE line formation of Fe in late-type stars - III. 3D non-LTE analysis of metal-poor stars
Part of Monthly notices of the Royal Astronomical Society, p. 1518-1533, 2016
Part of PHYSICAL REVIEW A, 2016
Part of Astronomy and Astrophysics, 2016
Inelastic processes in atomic, molecular and chemical physics (in honour of Andrey K. Belyaev)
Part of Chemical Physics, p. 1-2, 2015
Atomic and molecular data for optical stellar spectroscopy
Part of Physica Scripta, 2015
A major upgrade of the VALD database
Part of Physica Scripta, 2015
Mg line formation in late-type stellar atmospheres: I. The model atom
Part of Astronomy and Astrophysics, 2015
The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo
Part of Astronomy and Astrophysics, 2015
Part of Astronomy and Astrophysics, 2015
- DOI for Unified numerical model of collisional depolarization and broadening rates that are due to hydrogen atom collisions
- Download full text (pdf) of Unified numerical model of collisional depolarization and broadening rates that are due to hydrogen atom collisions
Inelastic silicon-hydrogen collision data for non-LTE applications in stellar atmospheres
Part of Astronomy and Astrophysics, 2014
Atomic diffusion and mixing in old stars IV. Weak abundance trends in the globular cluster NGC6752
Part of Astronomy and Astrophysics, 2013
Part of Astrophysical Journal, p. 27, 2013
The most metal-poor stars. IV. the two populations with [Fe/H] ≲ -3.0
Part of Astrophysical Journal, p. 28, 2013
The most metal-poor stars. I. Discovery, data, and atmospheric parameters
Part of Astrophysical Journal, p. 25, 2013
Part of Astrophysical Journal, p. 26, 2013
The influence of electron collisions on non-LTE Li line formation in stellar atmospheres
Part of Journal of Physics, Conference Series, 2012
Cross sections for low-energy inelastic Mg + H and Mg+ + H- collisions
Part of Physical Review A. Atomic, Molecular, and Optical Physics, 2012
Inelastic Mg plus H collision data for non-LTE applications in stellar atmospheres
Part of Astronomy and Astrophysics, 2012
Low-energy inelastic Na + H collisions
Part of Journal of Physics, Conference Series, 2012
Ab initio cross sections for low-energy inelastic Mg+H collisions
Part of Journal of Physics, Conference Series, 2012
Mg-H collision rates for non-LTE determination of stellar atmospheric parameters
Part of Journal of Physics, Conference Series, 2012
HERES VI. Galactic chemical evolution of Si and C (Zhang+, 2011)
Part of VizieR Online Data Catalog, 2011
Part of Astronomy and Astrophysics, 2011
Multichannel excitation cross sections of sodium atoms at slow collisions with hydrogen atoms
Part of Optics and Spectroscopy, p. 321-327, 2011
The influence of electron collisions on non-LTE Li line formation in stellar atmospheres
Part of Astronomy and Astrophysics, 2011
On inelastic hydrogen atom collisions in stellar atmospheres
Part of Astronomy and Astrophysics, 2011
Inelastic Mg plus H collision processes at low energies
Part of Journal of Physics B, 2011
Non-LTE calculations for neutral Na in late-type stars using improved atomic data
Part of Astronomy and Astrophysics, 2011
Cross sections for low-energy inelastic H plus Na collisions
Part of Physical Review A. Atomic, Molecular, and Optical Physics, 2010
Part of Astronomy and Astrophysics, 2010
Inelastic Na+H collision data for non-LTE applications in stellar atmospheres
Part of Astronomy and Astrophysics, 2010
LITHIUM ABUNDANCES OF EXTREMELY METAL-POOR TURNOFF STARS
Part of Astrophysical Journal, p. 1803-1812, 2009
Part of Physica Scripta, 2008
Part of Astronomy and Astrophysics, p. 327-337, 2007
Part of Astronomy and Astrophysics, p. 667-677, 2007
Part of Astrophysical Journal, p. 402-419, 2007
Part of Astronomy and Astrophysics, p. 1171-1177, 2007
Electron-impact excitation of neutral oxygen
Part of Astronomy and Astrophysics, p. 781-788, 2007
A probable stellar solution to the cosmological lithium discrepancy
Part of Nature, p. 657-659, 2006
The frequency of carbon-enhanced metal-poor stars in the galaxy from the HERES sample
Part of Astrophysical Journal, 2006
HE 1327-2326, an Unevolved Star with [Fe/H] < -5.0.: I. A Comprehensive Abundance Analysis
Part of The Astrophysical Journal, p. 897-917, 2006
Part of Astronomy and Astrophysics, p. 651-670, 2006
Efficient Searches for r-Process-Enhanced, Metal-Poor Stars
Part of Nuclear Physics A, p. 595-598, 2005
The broadening of Fe II lines by neutral hydrogen collisions
Part of Astronomy and Astrophysics, p. 373-377, 2005
Collisional depolarization of the lines of complex atoms/ions by neutral hydrogen
Part of Astronomy and Astrophysics, p. 779-784, 2005
Part of Astronomy and Astrophysics, p. 395-406, 2005
Nucleosynthetic signatures of the first stars
Part of Nature, p. 871-873, 2005
Part of Astronomy and Astrophysics, p. 129-151, 2005
Part of Astronomy and Astrophysics, p. 707-715, 2004
Collisional broadening of Mg, Sr, Ca and Na resonance lines by atomic hydrogen
Part of Journal of Physics B: Atomic, Molecular and Optical Physics, p. 677-688, 2004
S4N: A Spectroscopic Survey of Stars in the Solar Neighborhood
Part of Astronomy and Astrophysics, p. 183-205, 2004
Part of Astronomy and Astrophysics, p. 373-376, 2004
Part of Astronomy and Astrophysics, p. 1027-1037, 2004
HE0107, A Chemically Ancient Star.: I. A Detailed Abundance Analysis
Part of The Astrophysical Journal, p. 708-728, 2004
Cross sections for low-energy inelastic H+Li collisions
Part of Physical Review A, p. 2703, 2003
Inelastic H+Li and H-+Li+ collisions and non-LTE Li I line formation in stellar atmospheres
Part of Astronomy & Astrophysics, 2003
Accurate atomic parameters for near-infrared spectral lines
Part of Astronomy & Astrophysics, p. 749-762, 2003
Part of Astronomy & Astrophysics, p. 369-373, 2003
Part of Astronomy & Astrophysics, p. 763-773, 2003
Detailed analysis of Balmer lines in cool dwarf stars
Part of Astronomy & Astrophysics, p. 951, 2002
Interpretation of the Core-Wing Anomaly of Balmer line profiles of cool Ap stars
Part of Astrophysical Journal Letters, p. 75-78, 2002
Abundance analysis of two late A-type stars HD 32115 and HD 37594
Part of Astron. Astrophys., p. 537-546, 2002
A stellar relic from the early Milky Way
Part of Nature, p. 904-906, 2002
Part of Journal of Physics B: Atomic, Molecular and Optical Physics, p. 4785-4799, 2001
Part of ASTROPHYSICAL JOURNAL, p. 830-851, 2001
Part of MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, p. 535-540, 2000
Self broadening of hydrogen lines: initial results
Part of ASTRONOMY AND ASTROPHYSICS, 2000
A list of data for the broadening of metallic lines by neutral hydrogen collisions
Part of ASTRONOMY & ASTROPHYSICS SUPPLEMENT SERIES, p. 467-473, 2000
Self-broadening in Balmer line wing formation in stellar atmospheres
Part of ASTRONOMY AND ASTROPHYSICS, p. 1091-1105, 2000
Articles, review/survey
Accurate abundance analysis of late-type stars: advances in atomic physics
Part of The Astronomy and Astrophysics Review, 2016
New Abundances for Old Stars – Atomic Diffusion at Work in NGC 6397
Part of The Messenger, p. 6-10, 2006
Conference papers
Final state resolved mutual neutralization of Li+ and D-
Part of 31St International Conference On Photonic, Electronic And Atomic Collisions (Icpeac Xxxi), 2020
Negative ion relaxation and reactions in a cryogenic storage ring
Part of 31St International Conference On Photonic, Electronic And Atomic Collisions (Icpeac Xxxi), 2020
Modelling the spectrum of Mg in cool stars
Part of XXII International Conference on Spectral Line Shapes (ICSLS 2014), 2014
- DOI for Modelling the spectrum of Mg in cool stars
- Download full text (pdf) of Modelling the spectrum of Mg in cool stars
Precise effective temperatures of solar analog stars
Part of IAU Symposium, p. 328-331, 2012
Part of XXI INTERNATIONAL CONFERENCE ON SPECTRAL LINE SHAPES (ICSLS 2012), 2012
p. 197, 2007
Pinning Down Gravitational Settling
Part of Chemical Abundances and Mixing in Stars in the Milky Way and its Satellites, p. 294, 2006
The frequency of Carbon-enhanced stars in HERES and SDSS
Part of Proceedings of the International Symposium on Nuclear Astrophysics, 2006
The Hamburg/ESO R-process Enhanced Star survey (HERES).: Abundances
Part of From Lithium to Uranium: Elemental Tracers of Early Cosmic Evolution, IAU Symposium Proceedings of the international Astronomical Union 228, p. 439-443, 2005
Part of From Lithium to Uranium: Elemental Tracers of Early Cosmic Evolution, 2005
Self-broadening of Balmer Lines Using Asymptotic Potentials: Application to Stellar Spectroscopy
Part of 17th International Conference on Spectral Line Shapes, 2004
Balmer lines and effective temperatures in cool stars
Part of 12th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, p. 1103, 2003
Interpretation of the Core-Wing Anomaly of Balmer line profiles of cool Ap stars
Part of IAUS 210, Modelling of stellar atmospheres, 2003
Ab initio cross sections for low-energy inelastic H+Li collisions
2003
HERES: The Search for r-Process-Enhanced, Metal-Poor Stars
Part of Bulletin American Astronomical Society Meeting, 2003
Part of SF2A-2003: Semaine de l'Astrophysique Française, meeting held in Bordeaux, France, June 16-20, 2003., 2003
Accurate Atomic Parameters from the Solar Spectrum
Part of Frontiers of High Resolution Spectroscopy, 25th meeting of the IAU, Joint Discussion 20, 2003
Heres: the Search for R-Process Enhanced, Metal-Poor Stars
Part of Elemental Abundances in Old Stars and Damped Lyman-α Systems, 25th meeting of the IAU, Joint Discussion 15, 2003
Broadening of Spectral Lines by Collisions with H_atoms
Part of The Future of Cool-Star Astrophysics: 12th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, p. 1097-1102, 2003
Hydrogen Balmer Lines as Probes of Stellar Atmospheres
Part of IAUS 210, Modelling of stellar atmospheres, 2003
Hydrogen Line Formation in Cool Stars
Part of 11th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, p. 766, 2001
Recent Developments of the VALD Database
Part of 11th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, p. 878, 2001
Broadening of Spectral Lines of Singly Ionised Atoms by Collisions with Neutral Hydrogen Atoms
Part of 11th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, ASP Conference Proceedings, Vol. 223., p. 772, 2001