@article{KramerLaeuter2019, author = {Kramer, Tobias and L{\"a}uter, Matthias}, title = {Outgassing induced acceleration of comet 67P/Churyumov-Gerasimenko}, volume = {630}, journal = {Astronomy \& Astrophysics}, arxiv = {http://arxiv.org/abs/1902.02701}, doi = {10.1051/0004-6361/201935229}, pages = {A4}, year = {2019}, abstract = {Cometary activity affects the orbital motion and rotation state due to sublimation induced forces. The availability of precise rotation-axis orientation and position data from the Rosetta mission allows one to accurately determine the outgassing of comet Churyumov-Gerasimenko/67P (67P). We derive the observed non-gravitational acceleration of 67P directly from the Rosetta spacecraft trajectory. From the non-gravitational acceleration we recover the diurnal outgassing variations and study a possible delay of the sublimation response with respect to the peak solar illumination. This allows us to compare the non-gravitational acceleration of 67P with expectations based on empirical models and common assumptions about the sublimation process. We use an iterative orbit refinement and Fourier decomposition of the diurnal activity to derive the outgassing induced non-gravitational acceleration. The uncertainties of the data reduction are established by a sensitivity analysis of an ensemble of best-fit orbits for comet 67P. We find that the Marsden non-gravitational acceleration parameters reproduce part of the non-gravitational acceleration but need to be augmented by an analysis of the nucleus geometry and surface illumination to draw conclusions about the sublimation process on the surface. The non-gravitational acceleration follows closely the subsolar latitude (seasonal illumination), with a small lag angle with respect to local noon around perihelion. The observed minor changes of the rotation axis do not favor forced precession models for the non-gravitational acceleration. In contrast to the sublimation induced torques, the non-gravitational acceleration does not put strong constraints on localized active areas on the nucleus. We find a close agreement of the orbit deduced non-gravitational acceleration and the water production independently derived from Rosetta in-situ measurement.}, language = {en} } @article{RodriguezKramer2019, author = {Rodr{\´i}guez, Mirta and Kramer, Tobias}, title = {Machine Learning of Two-Dimensional Spectroscopic Data}, volume = {520}, journal = {Chemical Physics}, arxiv = {http://arxiv.org/abs/1810.01124}, doi = {10.1016/j.chemphys.2019.01.002}, pages = {52 -- 60}, year = {2019}, abstract = {Two-dimensional electronic spectroscopy has become one of the main experimental tools for analyzing the dynamics of excitonic energy transfer in large molecular complexes. Simplified theoretical models are usually employed to extract model parameters from the experimental spectral data. Here we show that computationally expensive but exact theoretical methods encoded into a neural network can be used to extract model parameters and infer structural information such as dipole orientation from two dimensional electronic spectra (2DES) or reversely, to produce 2DES from model parameters. We propose to use machine learning as a tool to predict unknown parameters in the models underlying recorded spectra and as a way to encode computationally expensive numerical methods into efficient prediction tools. We showcase the use of a trained neural network to efficiently compute disordered averaged spectra and demonstrate that disorder averaging has non-trivial effects for polarization controlled 2DES.}, language = {en} } @article{KramerLaeuterHviidetal.2019, author = {Kramer, Tobias and L{\"a}uter, Matthias and Hviid, Stubbe and Jorda, Laurent and Keller, Horst Uwe and K{\"u}hrt, Ekkehard}, title = {Comet 67P/Churyumov-Gerasimenko rotation changes derived from sublimation induced torques}, volume = {630}, journal = {Astronomy \& Astrophysics}, arxiv = {http://arxiv.org/abs/1812.01490}, doi = {10.1051/0004-6361/201834349}, pages = {A3}, year = {2019}, abstract = {Context. The change of the rotation period and the orientation of the rotation axis of comet 67P/Churyumov-Gerasimenko (67P/C-G) is deducible from images taken by the scientific imaging instruments on-board the Rosetta mission with high precision. Non gravitational forces are a natural explanation for these data. Aims. We describe observed changes for the orientation of the rotation axis and the rotation period of 67P/C-G. For these changes we give an explanation based on a sublimation model with a best-fit for the surface active fraction (model P). Torque effects of periodically changing gas emissions on the surface are considered. Methods. We solve the equation of state for the angular momentum in the inertial and the body- fixed frames and provide an analytic theory of the rotation changes in terms of Fourier coefficients, generally applicable to periodically forced rigid body dynamics. Results. The torque induced changes of the rotation state constrain the physical properties of the surface, the sublimation rate and the local active fraction of the surface. Conclusions. We determine a distribution of the local surface active fraction in agreement with the rotation properties, period and orientation, of 67P/C-G. The torque movement confirms that the sublimation increases faster than the insolation towards perihelion. The derived relatively uniform activity pattern is discussed in terms of related surface features.}, language = {en} } @article{LaeuterKramerRubinetal.2019, author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {Surface localization of gas sources on comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data}, volume = {483}, journal = {Monthly Notices of the Royal Astronomical Society}, publisher = {Monthly Notices of the Royal Astronomical Society}, arxiv = {http://arxiv.org/abs/1804.06696}, doi = {10.1093/mnras/sty3103}, pages = {852 -- 861}, year = {2019}, abstract = {We reconstruct the temporal evolution of the source distribution for the four major gas species H2O, CO2, CO, and O2 on the surface of comet 67P/Churyumov-Gerasimenko during its 2015 apparition. The analysis applies an inverse coma model and fits to data between August 6th 2014 and September 5th 2016 measured with the Double Focusing Mass Spectrometer (DFMS) of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) and the COmet Pressure Sensor (COPS). The spatial distribution of gas sources with their temporal variation allows one to construct surface maps for gas emissions and to evaluate integrated productions rates. For all species peak production rates and integrated productions rates per orbit are evaluated separately for the northern and the southern hemisphere. The nine most active emitting areas on the comet's surface are defined and their correlation to emissions for each of the species is discussed.}, language = {en} } @article{KreisbeckKramerMolina2017, author = {Kreisbeck, Christoph and Kramer, Tobias and Molina, Rafael}, title = {Time-dependent wave packet simulations of transport through Aharanov-Bohm rings with an embedded quantum dot}, volume = {29}, journal = {Journal of Physics: Condensed Matter}, number = {15}, doi = {10.1088/1361-648X/aa605d}, pages = {155301}, year = {2017}, abstract = {We have performed time-dependent wave packet simulations of realistic Aharonov-Bohm (AB) devices with a quantum dot embedded in one of the arms of the interferometer. The AB ring can function as a measurement device for the intrinsic transmission phase through the quantum dot, however, care has to be taken in analyzing the influence of scattering processes in the junctions of the interferometer arms. We consider a harmonic quantum dot and show how the Darwin-Fock spectrum emerges as a unique pattern in the interference fringes of the AB oscillations.}, language = {en} } @article{KramerRodriguezZelinskyi2017, author = {Kramer, Tobias and Rodriguez, Mirta and Zelinskyi, Yaroslav}, title = {Modeling of Transient Absorption Spectra in Exciton Charge-Transfer Systems}, volume = {121}, journal = {Journal of Physical Chemistry B}, arxiv = {http://arxiv.org/abs/1811.10683}, doi = {10.1021/acs.jpcb.6b09858}, pages = {463 -- 470}, year = {2017}, abstract = {Time-resolved spectroscopy provides the main tool for analyzing the dynamics of excitonic energy transfer in light-harvesting complexes. To infer time-scales and effective coupling parameters from experimental data requires to develop numerical exact theoretical models. The finite duration of the laser-molecule interactions and the reorganization process during the exciton migration affect the location and strength of spectroscopic signals. We show that the non-perturbative hierarchical equations of motion (HEOM) method captures these processes in a model exciton system, including the charge transfer state.}, language = {en} } @article{KramerNoack2016, author = {Kramer, Tobias and Noack, Matthias}, title = {On the origin of inner coma structures observed by Rosetta during a diurnal rotation of comet 67P/Churyumov-Gerasimenko}, volume = {823}, journal = {The Astrophysical Journal Letters}, number = {1}, doi = {10.3847/2041-8205/823/1/L11}, pages = {L11}, year = {2016}, abstract = {The Rosetta probe around comet 67P/Churyumov-Gerasimenko (67P) reveals an anisotropic dust distribution of the inner coma with jet-like structures. The physical processes leading to jet formation are under debate, with most models for cometary activity focusing on localized emission sources, such as cliffs or terraced regions. Here we suggest, by correlating high-resolution simulations of the dust environment around 67P with observations, that the anisotropy and the background dust density of 67P originate from dust released across the entire sunlit surface of the nucleus rather than from few isolated sources. We trace back trajectories from coma regions with high local dust density in space to the non-spherical nucleus and identify two mechanisms of jet formation: areas with local concavity in either two dimensions or only one. Pits and craters are examples of the first case; the neck region of the bi-lobed nucleus of 67P is an example of the latter case. The conjunction of multiple sources, in addition to dust released from all other sunlit areas, results in a high correlation coefficient (~0.8) of the predictions with observations during a complete diurnal rotation period of 67P.}, language = {en} } @article{ReimersBiczyskoBruceetal.2016, author = {Reimers, Jeffrey R. and Biczysko, Malgorzata and Bruce, Douglas and Coker, David F. and Frankcombe, Terry J. and Hashimoto, Hideki and Hauer, J{\"u}rgen and Jankowiak, Ryszard and Kramer, Tobias and Linnanto, Juha and Mamedov, Fikret and M{\"u}h, Frank and R{\"a}tsep, Margus and Renger, Thomas and Styring, Stenbj{\"o}rn and Wan, Jian and Wang, Zhuan and Wang-Otomo, Zheng-Yu and Weng, Yu-Xiang and Yang, Chunhong and Zhang, Jian-Ping and Freiberg, Arvi and Krausz, Elmars}, title = {Challenges facing an understanding of the nature of low-energy excited states in photosynthesis}, volume = {1857}, journal = {BBA Bioenergetics}, number = {9}, doi = {10.1016/j.bbabio.2016.06.010}, pages = {1627 -- 1640}, year = {2016}, abstract = {While the majority of the photochemical states and pathways related to the biological capture of solar energy are now well understood and provide paradigms for artificial device design, additional low-energy states have been discovered in many systems with obscure origins and significance. However, as low-energy states are naively expected to be critical to function, these observations pose important challenges. A review of known properties of low energy states covering eight photochemical systems, and options for their interpretation, are presented. A concerted experimental and theoretical research strategy is suggested and outlined, this being aimed at providing a fully comprehensive understanding.}, language = {en} } @article{KramerKreisbeckRihaetal.2016, author = {Kramer, Tobias and Kreisbeck, Christoph and Riha, Christian and Chiatti, Olivio and Buchholz, Sven and Wieck, Andreas and Reuter, Dirk and Fischer, Saskia}, title = {Thermal energy and charge currents in multi-terminal nanorings}, volume = {6}, journal = {AIP Advances}, doi = {10.1063/1.4953812}, pages = {065306}, year = {2016}, abstract = {We study in experiment and theory thermal energy and charge transfer close to the quantum limit in a ballistic nanodevice, consisting of multiply connected one-dimensional electron waveguides. The fabricated device is based on an AlGaAs/GaAs heterostructure and is covered by a global top-gate to steer the thermal energy and charge transfer in the presence of a temperature gradient, which is established by a heating current. The estimate of the heat transfer by means of thermal noise measurements shows the device acting as a switch for charge and thermal energy transfer. The wave-packet simulations are based on the multi-terminal Landauer-B{\"u}ttiker approach and confirm the experimental finding of a mode-dependent redistribution of the thermal energy current, if a scatterer breaks the device symmetry.}, language = {en} } @misc{KramerNoack2016, author = {Kramer, Tobias and Noack, Matthias}, title = {On the origin of inner coma structures observed by Rosetta during a diurnal rotation of comet 67P/Churyumov-Gerasimenko.}, issn = {1438-0064}, doi = {10.3847/2041-8205/823/1/L11}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-59225}, year = {2016}, abstract = {The Rosetta probe around comet 67P/Churyumov-Gerasimenko (67P) reveals an anisotropic dust distribution of the inner coma with jet-like structures. The physical processes leading to jet formation are under debate, with most models for cometary activity focusing on localised emission sources, such as cliffs or terraced regions. Here we suggest, by correlating high-resolution simulations of the dust environment around 67P with observations, that the anisotropy and the background dust density of 67P originate from dust released across the entire sunlit surface of the nucleus rather than from few isolated sources. We trace back trajectories from coma regions with high local dust density in space to the non-spherical nucleus and identify two mechanisms of jet formation: areas with local concavity in either two dimensions or only one. Pits and craters are examples of the first case, the neck region of the bilobed nucleus of 67P for the latter one. The conjunction of multiple sources in addition to dust released from all other sunlit areas results in a high correlation coefficient (∼0.8) of the predictions with observations during a complete diurnal rotation period of 67P.}, language = {en} } @article{KramerNoackBaumetal.2015, author = {Kramer, Tobias and Noack, Matthias and Baum, Daniel and Hege, Hans-Christian and Heller, Eric J.}, title = {Homogeneous dust emission and jet structure near active cometary nuclei: the case of 67P/Churyumov-Gerasimenko}, arxiv = {http://arxiv.org/abs/1505.08041}, year = {2015}, abstract = {We compute trajectories of dust grains starting from a homogeneous surface activity-profile on a irregularly shaped cometary nucleus. Despite the initially homogeneous dust distribution a collimation in jet-like structures becomes visible. The fine structure is caused by concave topographical features with similar bundles of normal vectors. The model incorporates accurately determined gravitational forces, rotation of the nucleus, and gas-dust interaction. Jet-like dust structures are obtained for a wide range of gas-dust interactions. For the comet 67P/Churyumov-Gerasimenko, we derive the global dust distribution around the nucleus and find several areas of agreement between the homogeneous dust emission model and the Rosetta observation of dust jets, including velocity-dependent bending of trajectories.}, language = {en} } @inproceedings{NoackReinefeldKrameretal.2018, author = {Noack, Matthias and Reinefeld, Alexander and Kramer, Tobias and Steinke, Thomas}, title = {DM-HEOM: A Portable and Scalable Solver-Framework for the Hierarchical Equations of Motion}, booktitle = {2018 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW), 19th IEEE Int. Workshop on Parallel and Distributed Scientific and Engineering Computing (PDSEC 2018)}, isbn = {978-1-5386-5555-9}, doi = {10.1109/IPDPSW.2018.00149}, pages = {947 -- 956}, year = {2018}, abstract = {Computing the Hierarchical Equations of Motion (HEOM) is by itself a challenging problem, and so is writing portable production code that runs efficiently on a variety of architectures while scaling from PCs to supercomputers. We combined both challenges to push the boundaries of simulating quantum systems, and to evaluate and improve methodologies for scientific software engineering. Our contributions are threefold: We present the first distributed memory implementation of the HEOM method (DM-HEOM), we describe an interdisciplinary development workflow, and we provide guidelines and experiences for designing distributed, performance-portable HPC applications with MPI-3, OpenCL and other state-of-the-art programming models. We evaluated the resulting code on multi- and many-core CPUs as well as GPUs, and demonstrate scalability on a Cray XC40 supercomputer for the PS I molecular light harvesting complex.}, language = {en} } @article{KramerNoackReinefeldetal.2018, author = {Kramer, Tobias and Noack, Matthias and Reinefeld, Alexander and Rodr{\´i}guez, Mirta and Zelinskyi, Yaroslav}, title = {Efficient calculation of open quantum system dynamics and time-resolved spectroscopy with Distributed Memory HEOM (DM-HEOM)}, volume = {39}, journal = {Journal of Computational Chemistry}, number = {22}, publisher = {Wiley Periodicals, Inc.}, arxiv = {http://arxiv.org/abs/arXiv:1803.03498}, doi = {doi:10.1002/jcc.25354}, pages = {1779 -- 1794}, year = {2018}, abstract = {Time- and frequency resolved optical signals provide insights into the properties of light harvesting molecular complexes, including excitation energies, dipole strengths and orientations, as well as in the exciton energy flow through the complex. The hierarchical equations of motion (HEOM) provide a unifying theory, which allows one to study the combined effects of system-environment dissipation and non-Markovian memory without making restrictive assumptions about weak or strong couplings or separability of vibrational and electronic degrees of freedom. With increasing system size the exact solution of the open quantum system dynamics requires memory and compute resources beyond a single compute node. To overcome this barrier, we developed a scalable variant of HEOM. Our distributed memory HEOM, DM-HEOM, is a universal tool for open quantum system dynamics. It is used to accurately compute all experimentally accessible time- and frequency resolved processes in light harvesting molecular complexes with arbitrary system-environment couplings for a wide range of temperatures and complex sizes.}, language = {en} } @article{KramerNoackReimersetal.2018, author = {Kramer, Tobias and Noack, Matthias and Reimers, Jeffrey R. and Reinefeld, Alexander and Rodr{\´i}guez, Mirta and Yin, Shiwei}, title = {Energy flow in the Photosystem I supercomplex: comparison of approximative theories with DM-HEOM}, volume = {515}, journal = {Chemical Physics}, publisher = {Elsevier B.V.}, arxiv = {http://arxiv.org/abs/arXiv:1805.10484}, doi = {10.1016/j.chemphys.2018.05.028}, pages = {262 -- 271}, year = {2018}, abstract = {We analyze the exciton dynamics in PhotosystemI from Thermosynechococcus elongatus using the distributed memory implementation of the hierarchical equation of motion (DM-HEOM) for the 96 Chlorophylls in the monomeric unit. The exciton-system parameters are taken from a first principles calculation. A comparison of the exact results with Foerster rates and Markovian approximations allows one to validate the exciton transfer times within the complex and to identify deviations from approximative theories. We show the optical absorption, linear, and circular dichroism spectra obtained with DM-HEOM and compare them to experimental results.}, language = {en} } @article{HellerFleischmannKramer2019, author = {Heller, Eric J. and Fleischmann, Ragnar and Kramer, Tobias}, title = {Branched Flow}, arxiv = {http://arxiv.org/abs/1910.07086}, year = {2019}, abstract = {In many physical situations involving diverse length scales, waves or rays representing them travel through media characterized by spatially smooth, random, modest refractive index variations. "Primary" diffraction (by individual sub-wavelength features) is absent. Eventually the weak refraction leads to imperfect focal "cusps". Much later, a statistical regime characterized by momentum diffusion is manifested. An important intermediate regime is often overlooked, one that is diffusive only in an ensemble sense. Each realization of the ensemble possesses dramatic ray limit structure that guides the waves (in the same sense that ray optics is used to design lens systems). This structure is a universal phenomenon called branched flow. Many important phenomena develop in this intermediate regime. Here we give examples and some of the physics of this emerging field.}, language = {en} } @article{KramerRodriguez2020, author = {Kramer, Tobias and Rodr{\´i}guez, Mirta}, title = {Effect of disorder and polarization sequences on two-dimensional spectra of light harvesting complexes}, volume = {144}, journal = {Photosynthesis Research}, arxiv = {http://arxiv.org/abs/1912.03003}, doi = {10.1007/s11120-019-00699-6}, pages = {147 -- 154}, year = {2020}, abstract = {Two-dimensional electronic spectra (2DES) provide unique ways to track the energy transfer dynamics in light-harvesting complexes. The interpretation of the peaks and structures found in experimentally recorded 2DES is often not straightforward, since several processes are imaged simultaneously. The choice of specific pulse polarization sequences helps to disentangle the sometimes convoluted spectra, but brings along other disturbances. We show by detailed theoretical calculations how 2DES of the Fenna-Matthews-Olson complex are affected by rotational and conformational disorder of the chromophores.}, language = {en} } @inproceedings{Kramer2020, author = {Kramer, Tobias}, title = {Transient capture of electrons in magnetic fields, or: comets in the restricted three-body problem}, volume = {1612}, booktitle = {Journal of Physics: Conference Series}, edition = {Symmetries in Science XVIII}, arxiv = {http://arxiv.org/abs/1912.08593}, doi = {10.1088/1742-6596/1612/1/012019}, pages = {012019}, year = {2020}, abstract = {The motion of celestial bodies in astronomy is closely related to the orbits of electrons encircling an atomic nucleus. Bohr and Sommerfeld presented a quantization scheme of the classical orbits to analyze the eigenstates of the hydrogen atom. Here we discuss another close connection of classical trajectories and quantum mechanical states: the transient dynamics of objects around a nucleus. In this setup a comet (or an electron) is trapped for a while in the vicinity of parent object (Jupiter or an atomic nucleus), but eventually escapes after many revolutions around the center of attraction.}, language = {en} } @article{HoangGarnierLasueetal.2020, author = {Hoang, Margaux and Garnier, Philippe and Lasue, Jeremie and R{\`e}me, Henri and Capria, Maria Teresa and Altwegg, Kathrin and L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin}, title = {Investigating the Rosetta/RTOF observations of comet 67P/Churyumov-Gerasimenko using a comet nucleus model: Influence of dust mantle and trapped CO}, volume = {638}, journal = {Astronomy \& Astrophysics}, doi = {10.1051/0004-6361/201936655}, pages = {A106}, year = {2020}, abstract = {Context. Cometary outgassing is induced by the sublimation of ices and the ejection of dust originating from the nucleus. Therefore measuring the composition and dynamics of the cometary gas provides information concerning the interior composition of the body. Nevertheless, the bulk composition differs from the coma composition, and numerical models are required to simulate the main physical processes induced by the illumination of the icy body. Aims. The objectives of this study are to bring new constraints on the interior composition of the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter 67P) by comparing the results of a thermophysical model applied to the nucleus of 67P and the coma measurements made by the Reflectron-type Time-Of-Flight (RTOF) mass spectrometer. This last is one of the three instruments of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), used during the Rosetta mission. Methods. Using a thermophysical model of the comet nucleus, we studied the evolution of the stratigraphy (position of the sublimation and crystallisation fronts), the temperature of the surface and subsurface, and the dynamics and spatial distribution of the volatiles (H2O, CO2 and CO). We compared them with the in situ measurements from ROSINA/RTOF and an inverse coma model. Results. We observed the evolution of the surface and near surface temperature, and the deepening of sublimation fronts. The thickness of the dust layer covering the surface strongly influences the H2O outgassing but not the more volatiles species. The CO outgassing is highly sensitive to the initial CO/H2O ratio, as well as to the presence of trapped CO in the amorphous ice. Conclusions. The study of the influence of the initial parameters on the computed volatile fluxes and the comparison with ROSINA/RTOF measurements provide a range of values for an initial dust mantle thickness and a range of values for the volatile ratio. These imply the presence of trapped CO. Nevertheless, further studies are required to reproduce the strong change of behaviour observed in RTOF measurements between September 2014 and February 2015.}, language = {en} } @article{LaeuterKramerRubinetal.2020, author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {The gas production of 14 species from comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data from 2014-2016}, volume = {498}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {3}, publisher = {Monthly Notices of the Royal Astronomical Society}, arxiv = {http://arxiv.org/abs/2006.01750}, doi = {10.1093/mnras/staa2643}, pages = {3995 -- 4004}, year = {2020}, abstract = {The coma of comet 67P/Churyumov-Gerasimenko has been probed by the Rosetta spacecraft and shows a variety of different molecules. The ROSINA COmet Pressure Sensor and the Double Focusing Mass Spectrometer provide in-situ densities for many volatile compounds including the 14 gas species H2O, CO2, CO, H2S, O2, C2H6, CH3OH, H2CO, CH4, NH3, HCN, C2H5OH, OCS, and CS2. We fit the observed densities during the entire comet mission between August 2014 and September 2016 to an inverse coma model. We retrieve surface emissions on a cometary shape with 3996 triangular elements for 50 separated time intervals. For each gas we derive systematic error bounds and report the temporal evolution of the production, peak production, and the time-integrated total production. We discuss the production for the two lobes of the nucleus and for the northern and southern hemispheres. Moreover we provide a comparison of the gas production with the seasonal illumination.}, language = {en} } @inproceedings{LaeuterKramerRubinetal.2020, author = {L{\"a}uter, Matthias and Kramer, Tobias and Rubin, Martin and Altwegg, Kathrin}, title = {Gas production for 14 species on comet 67P/Churyumov-Gerasimenko from 2014-2016}, volume = {14}, booktitle = {Europlanet Science Congress}, publisher = {Europlanet Science Congress}, doi = {10.5194/epsc2020-319}, pages = {EPSC2020-319}, year = {2020}, abstract = {During a two year period between 2014 and 2016 the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) has been probed by the Rosetta spacecraft. Density data for 14 gas species was recorded with the COmet Pressure Sensor (COPS) and the Double Focusing Mass Spectrometer (DFMS) being two sensors of the ROSINA instrument. The combination with an inverse gas model yields emission rates on each of 3996 surface elements of a surface shape for the cometary nucleus. The temporal evolution of gas production, of relative abundances, and peak productions weeks after perihelion are investigated. Solar irradiation and gas production are in a complex relation revealing features differing for gas species, for mission time, and for the hemispheres of the comet. This characterization of gas composition allows one to correlate 67P/C-G to other solar and interstellar comets, their formation conditions and nucleus properties, see [Bodewits D., et al., 2020 Nature Astronomy].}, language = {en} }