Search

Your search keyword '"Fiethe, B."' showing total 122 results
Start Over Author "Fiethe, B." Search Limiters Available in Library Collection

Refine your results

more »

more »

more »
122 results on '"Fiethe, B."'

1. Reconstruction of total solar irradiance variability as simultaneously apparent from Solar Orbiter and Solar Dynamics Observatory

Author

Yeo, K. L., Krivova, N. A., Solanki, S. K., Hirzberger, J., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Gutierrez-Marques, P., Kahil, F., Kolleck, M., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Calchetti, D., Carmona, M., Feller, A., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Maue, T., Meller, R., Vacas, A. Moreno, Müller, R., Nakai, E., Schmidt, W., Schou, J., Sinjan, J., Staub, J., Strecker, H., Torralbo, I., and Valori, G.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Solar irradiance variability has been monitored almost exclusively from the Earth's perspective. {We present a method to combine the unprecedented observations of the photospheric magnetic field and continuum intensity from outside the Sun-Earth line, which is being recorded by the Polarimetric and Helioseismic Imager on board the Solar Orbiter mission (SO/PHI), with solar observations recorded from the Earth's perspective to examine the solar irradiance variability from both perspectives simultaneously.} Taking SO/PHI magnetograms and continuum intensity images from the cruise phase of the Solar Orbiter mission and concurrent observations from the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO/HMI) as input into the SATIRE-S model, we successfully reconstructed the total solar irradiance variability as apparent from both perspectives. In later stages of the SO mission, the orbital plane will tilt in such a way as to bring the spacecraft away from the ecliptic to heliographic latitudes of up to $33^{\circ}$. The current study sets the template for the reconstruction of solar irradiance variability as seen from outside the ecliptic from data that SO/PHI is expected to collect from such positions. {Such a reconstruction will be beneficial to factoring inclination into how the brightness variations of the Sun compare to those of other cool stars, whose rotation axes are randomly inclined.

Published
2023
Full Text
View/download PDF

2. Coronal voids and their magnetic nature

Author

Nölke, J. D., Solanki, S. K., Hirzberger, J., Peter, H., Chitta, L. P., Kahil, F., Valori, G., Wiegelmann, T., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Germerott, D., Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Cama, J. M. Gómez, Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Calchetti, D., Carmona, M., Deutsch, W., Feller, A., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Lange, T., Jiménez, A. López, Maue, T., Meller, R., Vacas, A. Moreno, Müller, R., Nakai, E., Schmidt, W., Schou, J., Schühle, U., Sinjan, J., Staub, J., Strecker, H., Torralbo, I., Berghmans, D., Kraaikamp, E., Rodriguez, L., Verbeeck, C., Zhukov, A. N., Auchere, F., Buchlin, E., Parenti, S., Janvier, M., Barczynski, K., Harra, L., Schwanitz, C., Cuadrado, R. Aznar, Mandal, S., Teriaca, L., Long, D., and Smith, P.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood. We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In particular, we aim to understand whether these voids result from a reduced heat input into the corona or if they are associated with mainly unipolar and possibly open magnetic fields, similar to coronal holes. We defined the coronal voids via an intensity threshold of 75% of the mean quiet-Sun (QS) EUV intensity observed by the high-resolution EUV channel (HRIEUV) of the Extreme Ultraviolet Imager on Solar Orbiter. The line-of-sight magnetograms of the same solar region recorded by the High Resolution Telescope of the Polarimetric and Helioseismic Imager allowed us to compare the photospheric magnetic field beneath the coronal voids with that in other parts of the QS. The coronal voids studied here range in size from a few granules to a few supergranules and on average exhibit a reduced intensity of 67% of the mean value of the entire field of view. The magnetic flux density in the photosphere below the voids is 76% (or more) lower than in the surrounding QS. Specifically, the coronal voids show much weaker or no network structures. The detected flux imbalances fall in the range of imbalances found in QS areas of the same size. Conclusions. We conclude that coronal voids form because of locally reduced heating of the corona due to reduced magnetic flux density in the photosphere. This makes them a distinct class of (dark) structure, different from coronal holes., Comment: 10 pages, 11 figures

Published
2023
Full Text
View/download PDF

3. Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points

Author

Albert, K., Krivova, N. A., Hirzberger, J., Solanki, S. K., Vacas, A. Moreno, Suárez, D. Orozco, Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Gutierrez-Marques, P., Kahil, F., Kolleck, M., Volkmer, R., Iniesta, J. C. del Toro, Woch, J., Fiethe, B., Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Calchetti, D., Carmona, M., Feller, A., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Lange, T., Jiménez, A. López, Maue, T., Meller, R., Müller, R., Nakai, E., Schmidt, W., Schou, J., Sinjan, J., Staub, J., Strecker, H., Torralbo, I., and Valori, G.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, assessment of this relationship has until now been hindered by the increasingly lower signal in magnetograms. This preliminary study aims at highlighting the potential of using simultaneous observations from different vantage points to better determine the properties of faculae close to the limb. We use data from the Solar Orbiter/Polarimetric and Helioseismic Imager (SO/PHI), and the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI), recorded at $\sim60^\circ$ angular separation of their lines of sight at the Sun. We use continuum intensity observed close to the limb by SO/PHI and complement it with the co-observed $B_{\rm LOS}$ from SDO/HMI, originating closer to disc centre (as seen by SDO/HMI), thus avoiding the degradation of the magnetic field signal near the limb. We derived the dependence of facular brightness in the continuum on disc position and magnetic flux density from the combined observations of SO/PHI and SDO/HMI. Compared with a single point of view, we were able to obtain contrast values reaching closer to the limb and to lower field strengths. We find the general dependence of the limb distance at which the contrast is maximum on the flux density to be at large in line with single viewpoint observations, in that the higher the flux density is, the closer the turning point lies to the limb. There is a tendency, however, for the maximum to be reached closer to the limb when determined from two vantage points. We note that due to the preliminary nature of this study, these results must be taken with caution. Our analysis shows that studies involving two viewpoints can significantly improve the detection of faculae near the solar limb and the determination of their brightness contrast relative to the quiet Sun.

Published
2023
Full Text
View/download PDF

4. Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

Author

Kahil, F., Gandorfer, A., Hirzberger, J., Calchetti, D., Sinjan, J., Valori, G., Solanki, S. K., Van Noort, M., Albert, K., Jorge, N. Albelo, Alvarez-Herrero, A., Appourchaux, T., Rubio, L. R. Bellot, guez, J. Blanco Rodrí, Feller, A., Fiethe, B., Germerott, D., Gizon, L., Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Korpi-Lagg, A., Michalik, H., Vacas, A. Moreno, arez, D. Orozco Su\', erez-Grande, I. P\', Kilders, E. Sanchis, Schou, J., uhle, U. Sch\", Staub, J., Strecker, H., iniesta, J. C. del Toro, Volkmer, R., and Woch, J.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. We use a pair of focused--defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances $>0.5$\,au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances $<0.5$\,au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed `aberration correction', which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only $1.45$ compared to the factor of $3$ increase that results from the usual PD reconstructions.

Published
2023
Full Text
View/download PDF

5. The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations

Author

Schou, J., Hirzberger, J., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Germerott, D., Guerrero, L., Gutierrez-Marques, P., Kahil, F., Kolleck, M., Solanki, S. K., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Calchetti, D., Carmona, M., Deutsch, W., Feller, A., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Jiménez, A. López, Maue, T., Meller, R., Vacas, A. Moreno, Müller, R., Nakai, E., Schmidt, W., Sinjan, J., Staub, J., Strecker, H., Torralbo, I., and Valori, G.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

In order to make accurate inferences about the solar interior using helioseismology, it is essential to understand all the relevant physical effects on the observations. One effect to understand is the (complex-valued) ratio of the horizontal to vertical displacement of the p- and f-modes at the height at which they are observed. Unfortunately, it is impossible to measure this ratio directly from a single vantage point, and it has been difficult to disentangle observationally from other effects. In this paper we attempt to measure the ratio directly using 7.5 hours of simultaneous observations from the Polarimetric and Helioseismic Imager on board Solar Orbiter and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. While image geometry problems make it difficult to determine the exact ratio, it appears to agree well with that expected from adiabatic oscillations in a standard solar model. On the other hand it does not agree with a commonly used approximation, indicating that this approximation should not be used in helioseismic analyses. In addition, the ratio appears to be real-valued., Comment: Accepted for publication in Astronomy & Astrophysics. 8 pages, 8 figures

Published
2023
Full Text
View/download PDF

6. The on-ground data reduction and calibration pipeline for SO/PHI-HRT

Author

Sinjan, J., Calchetti, D., Hirzberger, J., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Germerott, D., Guerrero, L., Marquez, P. Gutierrez, Kahil, F., Kolleck, M., Solanki, S. K., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Cama, J. M. Gómez, Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Carmona, M., Deutsch, W., Fernandez-Rico, G., Fernández-Medina, A., Parejo, P. García, Blesa, J. L. Gasent, Gizon, L., Grauf, B., Heerlein, K., Korpi-Lagg, A., Lange, T., Jiménez, A. López, Maue, T., Meller, R., Michalik, H., Vacas, A. Moreno, Müller, R., Nakai, E., Schmidt, W., Schou, J., Schühle, U., Staub, J., Strecker, H., Torralbo, I., and Valori, G.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The ESA/NASA Solar Orbiter space mission has been successfully launched in February 2020. Onboard is the Polarimetric and Helioseismic Imager (SO/PHI), which has two telescopes, a High Resolution Telescope (HRT) and the Full Disc Telescope (FDT). The instrument is designed to infer the photospheric magnetic field and line-of-sight velocity through differential imaging of the polarised light emitted by the Sun. It calculates the full Stokes vector at 6 wavelength positions at the Fe I 617.3 nm absorption line. Due to telemetry constraints, the instrument nominally processes these Stokes profiles onboard, however when telemetry is available, the raw images are downlinked and reduced on ground. Here the architecture of the on-ground pipeline for HRT is presented, which also offers additional corrections not currently available on board the instrument. The pipeline can reduce raw images to the full Stokes vector with a polarimetric sensitivity of $10^{-3}\cdot I_{c}$ or better.

Published
2022
Full Text
View/download PDF

7. The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter

Author

Kahil, F., Hirzberger, J., Solanki, S. K., Chitta, L. P., Peter, H., Auchère, F., Sinjan, J., Suárez, D. Orozco, Albert, K., Jorge, N. Albelo, Appourchaux, T., Alvarez-Herrero, A., Rodríguez, J. Blanco, Gandorfer, A., Germerott, D., Guerrero, L., Márquez, P. Gutiérrez, Kolleck, M., Iniesta, J. C. del Toro, Volkmer, R., Woch, J., Fiethe, B., Cama, J. M. Gómez, Pérez-Grande, I., Kilders, E. Sanchis, Jiménez, M. Balaguer, Rubio, L. R. Bellot, Calchetti, D., Carmona, M., Deutsch, W., Fernández-Rico, G., Fernández-Medina, A., Parejo, P. García, Gasent-Blesa, J. L., Gizon, L., Grauf, B., Heerlein, K., Lagg, A., Lange, T., Jiménez, A. López, Maue, T., Meller, R., Michalik, H., Vacas, A. Moreno, uller, R. M\", Nakai, E., Schmidt, W., Schou, J., Schühle, U., Staub, J., Strecker, H., Torralbo, I., Valori, G., Cuadrado, R. Aznar, Teriaca, L., Berghmans, D., Verbeeck, C., Kraaikamp, E., and Gissot, S.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Physics - Space Physics
Abstract

The Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter (SO) spacecraft observed small extreme ultraviolet (EUV) bursts, termed campfires, that have been proposed to be brightenings near the apexes of low-lying loops in the quiet-Sun atmosphere. The underlying magnetic processes driving these campfires are not understood. During the cruise phase of SO and at a distance of 0.523\,AU from the Sun, the Polarimetric and Helioseismic Imager on Solar Orbiter (SO/PHI) observed a quiet-Sun region jointly with SO/EUI, offering the possibility to investigate the surface magnetic field dynamics underlying campfires at a spatial resolution of about 380~km. In 71\% of the 38 isolated events, campfires are confined between bipolar magnetic features, which seem to exhibit signatures of magnetic flux cancellation. The flux cancellation occurs either between the two main footpoints, or between one of the footpoints of the loop housing the campfire and a nearby opposite polarity patch. In one particularly clear-cut case, we detected the emergence of a small-scale magnetic loop in the internetwork followed soon afterwards by a campfire brightening adjacent to the location of the linear polarisation signal in the photosphere, that is to say near where the apex of the emerging loop lays. The rest of the events were observed over small scattered magnetic features, which could not be identified as magnetic footpoints of the campfire hosting loops. The majority of campfires could be driven by magnetic reconnection triggered at the footpoints, similar to the physical processes occurring in the burst-like EUV events discussed in the literature. About a quarter of all analysed campfires, however, are not associated to such magnetic activity in the photosphere, which implies that other heating mechanisms are energising these small-scale EUV brightenings.

Published
2022
Full Text
View/download PDF

8. ROSINA ion zoo at Comet 67P

Author

Beth, A., Altwegg, K., Balsiger, H., Berthelier, J. -J., Combi, M. R., De Keyser, J., Fiethe, B., Fuselier, S. A., Galand, M., Gombosi, T. I., Rubin, M., and Sémon, T.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The Rosetta spacecraft escorted Comet 67P/Churyumov-Gerasimenko for 2 years along its journey through the Solar System between 3.8 and 1.24~au. Thanks to the high resolution mass spectrometer on board Rosetta, the detailed ion composition within a coma has been accurately assessed in situ for the very first time. Previous cometary missions, such as $\text{Giotto}$, did not have the instrumental capabilities to identify the exact nature of the plasma in a coma because the mass resolution of the spectrometers onboard was too low to separate ion species with similar masses. In contrast, the Double Focusing Mass Spectrometer (DFMS), part of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis on board Rosetta (ROSINA), with its high mass resolution mode, outperformed all of them, revealing the diversity of cometary ions. We calibrated and analysed the set of spectra acquired by DFMS in ion mode from October 2014 to April 2016. In particular, we focused on the range from 13-39 u$\cdot$q$^{-1}$. The high mass resolution of DFMS allows for accurate identifications of ions with quasi-similar masses, separating $^{13}$C$^+$ from CH$^+$, for instance. We confirm the presence in situ of predicted cations at comets, such as CH$_m^+$ ($m=1-4$), H$_n$O$^+$ ($n=1-3$), O$^+$, Na$^+$, and several ionised and protonated molecules. Prior to Rosetta, only a fraction of them had been confirmed from Earth-based observations. In addition, we report for the first time the unambiguous presence of a molecular dication in the gas envelope of a Solar System body, namely CO$_2^{++}$., Comment: Accepted for publication in A&A

Published
2020
Full Text
View/download PDF

9. Evidence of ammonium salts in comet 67P as explanation for the nitrogen depletion in cometary comae

Author

Altwegg, K., Balsiger, H., Berthelier, J. -J., Briois, C., Combi, M., Cottin, H., De Keyser, J., Dhooghe, F., Fiethe, B., Fuselier, S. A., Gombosi, T. I., Hänni, N., Rubin, M., Schuhmann, M., Schroeder, I., Sémon, T., and Wampfler, S.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Cometary comae are generally depleted in nitrogen. The main carriers for volatile nitrogen in comets are NH3 and HCN. It is known that ammonia readily combines with many acids like e.g. HCN, HNCO, HCOOH, etc. encountered in the interstellar medium as well as in cometary ice to form ammonium salts (NH4+X-) at low temperatures. Ammonium salts, which can play a significant role in prebiotic chemistry, are hard to detect in space as they are unstable in the gas phase and their infrared signature is often hidden by thermal radiation or by e.g. OH in minerals. Here we report the presence of all possible sublimation products of five different ammonium salts at comet 67P/Churyumov-Gerasimenko measured by the ROSINA instrument on Rosetta. The relatively high sublimation temperatures of the salts leads to an apparent lack of volatile nitrogen in the coma. This then also explains the observed trend of higher NH3/H2O ratios with decreasing perihelion distances in comets.

Published
2019

10. Performance analysis of the SO/PHI software framework for on-board data reduction

Author

Albert, K., Hirzberger, J., Busse, D., Rodríguez, J. Blanco, Durán, J. S. Castellanos, Carrascosa, J. P. Cobos, Fiethe, B., Gandorfer, A., Guan, Y., Kolleck, M., Lagg, A., Lange, T., Michalik, H., Solanki, S. K., Iniesta, J. C. del Toro, and Woch, J.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

The Polarimetric and Helioseismic Imager (PHI) is the first deep-space solar spectropolarimeter, on-board the Solar Orbiter (SO) space mission. It faces: stringent requirements on science data accuracy, a dynamic environment, and severe limitations on telemetry volume. SO/PHI overcomes these restrictions through on-board instrument calibration and science data reduction, using dedicated firmware in FPGAs. This contribution analyses the accuracy of a data processing pipeline by comparing the results obtained with SO/PHI hardware to a reference from a ground computer. The results show that for the analysed pipeline the error introduced by the firmware implementation is well below the requirements of SO/PHI., Comment: From the Astronomical Data Analysis and Software Systems 2018 conference

Published
2019

11. The Polarimetric and Helioseismic Imager on Solar Orbiter

Author

Solanki, S. K., Iniesta, J. C. del Toro, Woch, J., Gandorfer, A., Hirzberger, J., Alvarez-Herrero, A., Appourchaux, T., Pillet, V. Martínez, Pérez-Grande, I., Kilders, E. Sanchis, Schmidt, W., Cama, J. M. Gómez, Michalik, H., Deutsch, W., Fernandez-Rico, G., Grauf, B., Gizon, L., Heerlein, K., Kolleck, M., Lagg, A., Meller, R., Müller, R., Schühle, U., Staub, J., Albert, K., Copano, M. Alvarez, Beckmann, U., Bischoff, J., Busse, D., Enge, R., Frahm, S., Germerott, D., Guerrero, L., Löptien, B., Meierdierks, T., Oberdorfer, D., Papagiannaki, I., Ramanath, S., Schou, J., Werner, S., Yang, D., Zerr, A., Bergmann, M., Bochmann, J., Heinrichs, J., Meyer, S., Monecke, M., Müller, M. -F., Sperling, M., a, D. Álvarez Garcí, Aparicio, B., Jiménez, M. Balaguer, Rubio, L. R. Bellot, Carracosa, J. P. Cobos, Girela, F., Expósito, D. Hernández, Herranz, M., Labrousse, P., Jiménez, A. López, Suárez, D. Orozco, Ramos, J. L., Barandiarán, J., Bastide, L., Campuzano, C., Cebollero, M., Dávila, B., Fernández-Medina, A., Parejo, P. García, Garranzo-García, D., Laguna, H., Martín, J. A., Navarro, R., Peral, A. Núñez, Royo, M., Sánchez, A., Silva-López, M., Vera, I., Villanueva, J., Fourmond, J. -J., de Galarreta, C. Ruiz, Bouzit, M., Hervier, V., Clec'h, J. C. Le, Szwec, N., Chaigneau, M., Buttice, V., Dominguez-Tagle, C., Philippon, A., Boumier, P., Cocguen, R. Le, Baranjuk, G., Bell, A., Berkefeld, Th., Baumgartner, J., Heidecke, F., Maue, T., Nakai, E., Scheiffelen, T., Sigwarth, M., Soltau, D., Volkmer, R., Rodríguez, J. Blanco, Domingo, V., Sabater, A. Ferreres, Blesa, J. L. Gasent, Martínez, P. Rodríguez, Caudel, D. Osorno, Bosch, J., Casas, A., Carmona, M., Herms, A., Roma, D., Alonso, G., omez-Sanjuan, A. G\', Piqueras, J., Torralbo, I., Fiethe, B., Guan, Y., Lange, T., Michel, H., Bonet, J. A., Fahmy, S., Müller, D., and Zouganelis, I.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler shift in the FeI 617.3nm spectral line. To this end, the instrument carries out narrow-band imaging spectro-polarimetry using a tunable LiNbO_3 Fabry-Perot etalon, while the polarisation modulation is done with liquid crystal variable retarders (LCVRs). The line and the nearby continuum are sampled at six wavelength points and the data are recorded by a 2kx2k CMOS detector. To save valuable telemetry, the raw data are reduced on board, including being inverted under the assumption of a Milne-Eddington atmosphere, although simpler reduction methods are also available on board. SO/PHI is composed of two telescopes; one, the Full Disc Telescope (FDT), covers the full solar disc at all phases of the orbit, while the other, the High Resolution Telescope (HRT), can resolve structures as small as 200km on the Sun at closest perihelion. The high heat load generated through proximity to the Sun is greatly reduced by the multilayer-coated entrance windows to the two telescopes that allow less than 4% of the total sunlight to enter the instrument, most of it in a narrow wavelength band around the chosen spectral line., Comment: 36 pages, 41 figures

Published
2019
Full Text
View/download PDF

12. Autonomous on-board data processing and instrument calibration software for the SO/PHI

Author

Albert, K., Hirzberger, J., Busse, D., Lange, T., Kolleck, M., Fiethe, B., Suárez, D. Orozco, Woch, J., Schou, J., Rodríguez, J. Blanco, Gandorfer, A., Guan, Y., Carrascosa, J. P. Cobos, Expósito, D. Hernández, Iniesta, J. C. del Toro, Solanki, S. K., and Michalik, H.

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

The extension of on-board data processing capabilities is an attractive option to reduce telemetry for scientific instruments on deep space missions. The challenges that this presents, however, require a comprehensive software system, which operates on the limited resources a data processing unit in space allows. We implemented such a system for the Polarimetric and Helioseismic Imager (PHI) on-board the Solar Orbiter (SO) spacecraft. It ensures autonomous operation to handle long command-response times, easy changing of the processes after new lessons have been learned and meticulous book-keeping of all operations to ensure scientific accuracy. This contribution presents the requirements and main aspects of the software implementation, followed by an example of a task implemented in the software frame, and results from running it on SO/PHI. The presented example shows that the different parts of the software framework work well together, and that the system processes data as we expect. The flexibility of the framework makes it possible to use it as a baseline for future applications with similar needs and limitations as SO/PHI., Comment: Conference: SPIE Astronomical Telescopes + Instrumentatio, Software and Cyberinfrastructure for AstronomyV

Published
2018
Full Text
View/download PDF

13. Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko

Author

Rubin, M., Altwegg, K., Balsiger, H., Berthelier, J. -J., Bieler, A., Calmonte, U., Combi, M., De Keyser, J., Engrand, C., Fiethe, B., Fuselier, S. A., Gasc, S., Gombosi, T. I., Hansen, K. C., Hässig, M., Roy, L. Le, Mezger, K., Tzou, C. -Y., Wampfler, S. F., and Wurz, P.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

Context. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) was designed to measure the composition of the gas in the coma of comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency's Rosetta mission. In addition to the volatiles, ROSINA measured refractories sputtered off the comet by the interaction of solar wind protons with the surface of the comet. Aims. The origin of different solar system materials is still heavily debated. Isotopic ratios can be used to distinguish between different reservoirs and investigate processes occurring during the formation of the solar system. Methods. ROSINA consisted of two mass spectrometers and a pressure sensor. In the ROSINA Double Focusing Mass Spectrometer (DFMS), the neutral gas of cometary origin was ionized and then deflected in an electric and a magnetic field that separated the ions based on their mass-to-charge ratio. The DFMS had a high mass resolution, dynamic range, and sensitivity that allowed detection of rare species and the known major volatiles. Results. We measured the relative abundance of all three stable silicon isotopes with the ROSINA instrument on board the Rosetta spacecraft. Furthermore, we measured $^{13}$C/$^{12}$C in C$_2$H$_4$, C$_2$H$_5$, and CO. The DFMS in situ measurements indicate that the average silicon isotopic composition shows depletion in the heavy isotopes $^{29}$Si and $^{30}$Si with respect to $^{28}$Si and solar abundances, while $^{13}$C to $^{12}$C is analytically indistinguishable from bulk planetary and meteorite compositions. Although the origin of the deficiency of the heavy silicon isotopes cannot be explained unambiguously, we discuss mechanisms that could have contributed to the measured depletion of the isotopes $^{29}$Si and $^{30}$Si., Comment: Accepted for publication in Astronomy & Astrophysics

Published
2017
Full Text
View/download PDF

14. Determination of the SO/PHI-HRT wavefront degradation using multiple defocused images

Author

Bailén, F.J., primary, Orozco Suárez, D., additional, Blanco Rodríguez, J., additional, del Toro Iniesta, J.C., additional, Strecker, H., additional, Moreno Vacas, A., additional, Santamarina Guerrero, P., additional, Hirzberger, J., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Gandorfer, A., additional, Germerott, D., additional, Guerrero, L., additional, Gutierrez-Marques, P., additional, Kahil, F., additional, Kolleck, M., additional, Solanki, S.K., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Gómez Cama, J.M., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L.R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent Blesa, J.L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, Lange, T., additional, López Jiménez, A., additional, Maue, T., additional, Meller, R., additional, Michalik, H., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schou, J., additional, Schühle, U., additional, Sinjan, J., additional, Staub, J., additional, Torralbo, I., additional, and Valori, G., additional

Published
2023
Full Text
View/download PDF

15. A first rapid synoptic magnetic field map using SDO/HMI andSO/PHI data

Author

Loeschl, P., primary, Valori, G., additional, Hirzberger, J., additional, Schou, J., additional, Solanki, S.K., additional, Orozco Suarez, D., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodriguez, J., additional, Gandorfer, A., additional, Germerott, D., additional, Guerrero, L., additional, Gutierrez-Marques, P., additional, Kahil, F., additional, Kolleck, M., additional, del Toro Iniesta, J.C., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Gómez Cama, J.M., additional, Perez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L.R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernandez-Medina, A., additional, Garcia Perejo, P., additional, Gasent Blesa, J.L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, Lange, T., additional, Lopez Jimenez, A., additional, Maue, T., additional, Meller, R., additional, Michalik, H., additional, Moreno Vacas, A., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schühle, U., additional, Sinjan, J., additional, Staub, J., additional, Strecker, H., additional, and Torralbo, I., additional

Published
2023
Full Text
View/download PDF

16. Reconstruction of total solar irradiance variability as simultaneously apparent from Solar Orbiter and Solar Dynamics Observatory

Author

Yeo, K. L., primary, Krivova, N. A., additional, Solanki, S. K., additional, Hirzberger, J., additional, Orozco Suárez, D., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodríguez, J., additional, Gandorfer, A., additional, Gutierrez-Marques, P., additional, Kahil, F., additional, Kolleck, M., additional, del Toro Iniesta, J. C., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Calchetti, D., additional, Carmona, M., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent Blesa, J. L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, Maue, T., additional, Meller, R., additional, Moreno Vacas, A., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schou, J., additional, Sinjan, J., additional, Staub, J., additional, Strecker, H., additional, Torralbo, I., additional, and Valori, G., additional

Published
2023
Full Text
View/download PDF

17. Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points

Author

Albert, K., primary, Krivova, N. A., additional, Hirzberger, J., additional, Solanki, S. K., additional, Moreno Vacas, A., additional, Orozco Suárez, D., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodríguez, J., additional, Gandorfer, A., additional, Gutierrez-Marques, P., additional, Kahil, F., additional, Kolleck, M., additional, Volkmer, R., additional, del Toro Iniesta, J. C., additional, Woch, J., additional, Fiethe, B., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent Blesa, J. L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, Lange, T., additional, López Jiménez, A., additional, Maue, T., additional, Meller, R., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schou, J., additional, Sinjan, J., additional, Staub, J., additional, Strecker, H., additional, Torralbo, I., additional, and Valori, G., additional

Published
2023
Full Text
View/download PDF

18. Coronal voids and their magnetic nature

Author

Nölke, J. D., primary, Solanki, S. K., additional, Hirzberger, J., additional, Peter, H., additional, Chitta, L. P., additional, Kahil, F., additional, Valori, G., additional, Wiegelmann, T., additional, Orozco Suárez, D., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodríguez, J., additional, Gandorfer, A., additional, Germerott, D., additional, Guerrero, L., additional, Gutierrez-Marques, P., additional, Kolleck, M., additional, del Toro Iniesta, J. C., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Gómez Cama, J. M., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent Blesa, J. L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, Lange, T., additional, López Jiménez, A., additional, Maue, T., additional, Meller, R., additional, Moreno Vacas, A., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schou, J., additional, Schühle, U., additional, Sinjan, J., additional, Staub, J., additional, Strecker, H., additional, Torralbo, I., additional, Berghmans, D., additional, Kraaikamp, E., additional, Rodriguez, L., additional, Verbeeck, C., additional, Zhukov, A. N., additional, Auchere, F., additional, Buchlin, E., additional, Parenti, S., additional, Janvier, M., additional, Barczynski, K., additional, Harra, L., additional, Schwanitz, C., additional, Aznar Cuadrado, R., additional, Mandal, S., additional, Teriaca, L., additional, Long, D., additional, and Smith, P., additional

Published
2023
Full Text
View/download PDF

19. Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

Author

Kahil, F., primary, Gandorfer, A., additional, Hirzberger, J., additional, Calchetti, D., additional, Sinjan, J., additional, Valori, G., additional, Solanki, S. K., additional, Van Noort, M., additional, Albert, K., additional, Albelo Jorge, N., additional, Alvarez-Herrero, A., additional, Appourchaux, T., additional, Bellot Rubio, L. R., additional, Blanco Rodríguez, J., additional, Feller, A., additional, Fiethe, B., additional, Germerott, D., additional, Gizon, L., additional, Guerrero, L., additional, Gutierrez-Marques, P., additional, Kolleck, M., additional, Korpi-Lagg, A., additional, Michalik, H., additional, Moreno Vacas, A., additional, Orozco Suárez, D., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Schou, J., additional, Schühle, U., additional, Staub, J., additional, Strecker, H., additional, del Toro Iniesta, J. C., additional, Volkmer, R., additional, and Woch, J., additional

Published
2023
Full Text
View/download PDF

20. The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations

Author

Schou, J., primary, Hirzberger, J., additional, Orozco Suárez, D., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodríguez, J., additional, Gandorfer, A., additional, Germerott, D., additional, Guerrero, L., additional, Gutierrez-Marques, P., additional, Kahil, F., additional, Kolleck, M., additional, Solanki, S. K., additional, del Toro Iniesta, J. C., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Feller, A., additional, Fernandez-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent Blesa, J. L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Korpi-Lagg, A., additional, López Jiménez, A., additional, Maue, T., additional, Meller, R., additional, Moreno Vacas, A., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Sinjan, J., additional, Staub, J., additional, Strecker, H., additional, Torralbo, I., additional, and Valori, G., additional

Published
2023
Full Text
View/download PDF

21. Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

Author

Ministerio de Ciencia e Innovación (España), European Commission, Kahil, F., Gandorfer, A., Hirzberger, J., Calchetti, D., Sinjan, J., Valori, G., Solanki, S. K., Van Noort, M., Albert, K., Albelo Jorge, N., Alvarez-Herrero, A., Appourchaux, T., Bellot Rubio, Luis R., Blanco Rodríguez, J., Feller, A., Fiethe, B., Germerott, D., Gizon, L., Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Korpi-Lagg, A., Michalik, H., Moreno Vacas, Alejandro, Orozco Suárez, David, Pérez Grande, Isabel, Sanchis Kilders, Esteban, Schou, J., Schühle, U., Staub, J., Strecker, H., Toro, José Carlos del, Volkmer, R., Woch, J., Ministerio de Ciencia e Innovación (España), European Commission, Kahil, F., Gandorfer, A., Hirzberger, J., Calchetti, D., Sinjan, J., Valori, G., Solanki, S. K., Van Noort, M., Albert, K., Albelo Jorge, N., Alvarez-Herrero, A., Appourchaux, T., Bellot Rubio, Luis R., Blanco Rodríguez, J., Feller, A., Fiethe, B., Germerott, D., Gizon, L., Guerrero, L., Gutierrez-Marques, P., Kolleck, M., Korpi-Lagg, A., Michalik, H., Moreno Vacas, Alejandro, Orozco Suárez, David, Pérez Grande, Isabel, Sanchis Kilders, Esteban, Schou, J., Schühle, U., Staub, J., Strecker, H., Toro, José Carlos del, Volkmer, R., and Woch, J.

Abstract

Aims. We use wavefront sensing to characterise the image quality of the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. Methods. We use a pair of focused–defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. Results. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances > 0.5 au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances < 0.5 au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed ‘aberration correction’, which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. Conclusions. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only 1.45 compared to the factor of 3 increase that results from the usual PD reconstructions. © The Authors 2023.

Published
2023

23. Abundant molecular oxygen in the coma of comet 67P/Churyumov-Gerasimenko

Author

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, E.F., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hassig, M., Jackel, A., Kopp, E., Korth, A., Roy, L. Le, Mall, U., Maggiolo, R., Marty, B., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.-Y., Waite, J.H., Walsh, C., and Wurz, P.

Subjects
Comets -- Chemical properties -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

The composition of the neutral gas comas of most comets is dominated by [H.sub.2]O, CO and C[O.sub.2], typically comprising as much as 95 per cent of the total gas density (1). In addition, cometary comas have been found to contain a rich array of other molecules, including sulfuric compounds and complex hydrocarbons. Molecular oxygen ([O.sub.2]), however, despite its detection on other icy bodies such as the moons of Jupiter and Saturn (2,3), has remained undetected in cometary comas. Here we report in situ measurement of [O.sub.2] in the coma of comet 67P/Churyumov-Gerasimenko, with local abundances ranging from one per cent to ten per cent relative to [H.sub.2]O and with a mean value of 3.80 ± 0.85 per cent. Our observations indicate that the [O.sub.2]/[H.sub.2]O ratio is isotropic in the coma and does not change systematically with heliocentric distance. This suggests that primordial [O.sub.2] was incorporated into the nucleus during the comet's formation, which is unexpected given the low upper limits from remote sensing observations (4). Current Solar System formation models do not predict conditions that would allow this to occur., Measurements of the coma of 67P/Churyumov-Gerasimenko (hereafter 67P) were made between September 2014 and March 2015 with the ROSINA-DFMS mass spectrometer (5) on board the Rosetta spacecraft. For the present [...]

Published
2015

24. The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter

Author

Kahil, F., primary, Hirzberger, J., additional, Solanki, S. K., additional, Chitta, L. P., additional, Peter, H., additional, Auchère, F., additional, Sinjan, J., additional, Orozco Suárez, D., additional, Albert, K., additional, Albelo Jorge, N., additional, Appourchaux, T., additional, Alvarez-Herrero, A., additional, Blanco Rodríguez, J., additional, Gandorfer, A., additional, Germerott, D., additional, Guerrero, L., additional, Gutiérrez Márquez, P., additional, Kolleck, M., additional, del Toro Iniesta, J. C., additional, Volkmer, R., additional, Woch, J., additional, Fiethe, B., additional, Gómez Cama, J. M., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Calchetti, D., additional, Carmona, M., additional, Deutsch, W., additional, Fernández-Rico, G., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Gasent-Blesa, J. L., additional, Gizon, L., additional, Grauf, B., additional, Heerlein, K., additional, Lagg, A., additional, Lange, T., additional, López Jiménez, A., additional, Maue, T., additional, Meller, R., additional, Michalik, H., additional, Moreno Vacas, A., additional, Müller, R., additional, Nakai, E., additional, Schmidt, W., additional, Schou, J., additional, Schühle, U., additional, Staub, J., additional, Strecker, H., additional, Torralbo, I., additional, Valori, G., additional, Aznar Cuadrado, R., additional, Teriaca, L., additional, Berghmans, D., additional, Verbeeck, C., additional, Kraaikamp, E., additional, and Gissot, S., additional

Published
2022
Full Text
View/download PDF

26. ROSINA ion zoo at Comet 67P

Author

Beth, Arnaud, Altwegg, K., Balsiger, H., Berthelier, J. -J., Combi, M. R., De Keyser, J., Fiethe, B., Fuselier, S. A., Galand, M., Gombosi, T. I., Rubin, M., Semon, T., Beth, Arnaud, Altwegg, K., Balsiger, H., Berthelier, J. -J., Combi, M. R., De Keyser, J., Fiethe, B., Fuselier, S. A., Galand, M., Gombosi, T. I., Rubin, M., and Semon, T.

Abstract

Context: The Rosetta spacecraft escorted Comet 67P/Churyumov-Gerasimenko for 2 yr along its journey through the Solar System between 3.8 and 1.24 au. Thanks to the high resolution mass spectrometer on board Rosetta, the detailed ion composition within a coma has been accurately assessed in situ for the very first time. Aims: Previous cometary missions, such as Giotto, did not have the instrumental capabilities to identify the exact nature of the plasma in a coma because the mass resolution of the spectrometers onboard was too low to separate ion species with similar masses. In contrast, the Double Focusing Mass Spectrometer (DFMS), part of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis on board Rosetta (ROSINA), with its high mass resolution mode, outperformed all of them, revealing the diversity of cometary ions. Methods: We calibrated and analysed the set of spectra acquired by DFMS in ion mode from October 2014 to April 2016. In particular, we focused on the range from 13–39 u q−1. The high mass resolution of DFMS allows for accurate identifications of ions with quasi-similar masses, separating 13C+ from CH+, for instance. Results: We confirm the presence in situ of predicted cations at comets, such as CHm+ (m = 1−4), HnO+ (n = 1−3), O+, Na+, and several ionised and protonated molecules. Prior to Rosetta, only a fraction of them had been confirmed from Earth-based observations. In addition, we report for the first time the unambiguous presence of a molecular dication in the gas envelope of a Solar System body, namely CO2++.

Published
2020
Full Text
View/download PDF

27. ALMA and ROSINA detections of phosphorus-bearing molecules: The interstellar thread between star-forming regions and comets

Author

Rivilla, V. M., Drozdovskaya, M. N., Altwegg, K., Caselli, P., Beltrán, M. T., Fontani, F., Van, Der, Tak, F. F. S., Cesaroni, R., Vasyunin, A., Rubin, M., Lique, F., Marinakis, S., Testi, L., Balsiger, H., Berthelier, J. J., De Keyser, J., Fiethe, B., Fuselier, S. A., Gasc, S., Gombosi, T. I., Sémon, T., Tzou, C. -Y., Rivilla, V. M., Drozdovskaya, M. N., Altwegg, K., Caselli, P., Beltrán, M. T., Fontani, F., Van, Der, Tak, F. F. S., Cesaroni, R., Vasyunin, A., Rubin, M., Lique, F., Marinakis, S., Testi, L., Balsiger, H., Berthelier, J. J., De Keyser, J., Fiethe, B., Fuselier, S. A., Gasc, S., Gombosi, T. I., Sémon, T., and Tzou, C. -Y.

Abstract

To understand how phosphorus (P)-bearing molecules are formed in star-forming regions, we have analysed the Atacama Large Millimeter/Submillimeter Array (ALMA) observations of PN and PO towards the massive star-forming region AFGL 5142, combined with a new analysis of the data of the comet 67P/Churyumov-Gerasimenko taken with the Rosetta Orbiter Spectrometer for Ion and NeutralAnalysis (ROSINA) instrument onboard Rosetta. TheALMA maps show that the emission of PN and PO arises from several spots associated with lowvelocity gas with narrow linewidths in the cavity walls of a bipolar outflow. PO is more abundant than PN in most of the spots, with the PO/PN ratio increasing as a function of the distance to the protostar. Our data favour a formation scenario in which shocks sputter phosphorus from the surface of dust grains, and gas-phase photochemistry induced by UV photons from the protostar allows efficient formation of the two species in the cavity walls. Our analysis of the ROSINA data has revealed that PO is the main carrier of P in the comet, with PO/PN > 10. Since comets may have delivered a significant amount of prebiotic material to the early Earth, this finding suggests that PO could contribute significantly to the phosphorus reservoir during the dawn of our planet. There is evidence that PO was already in the cometary ices prior to the birth of the Sun, so the chemical budget of the comet might be inherited from the natal environment of the Solar system, which is thought to be a stellar cluster including also massive stars. © 2019 The Author(s).

Published
2020

28. ROSINA ion zoo at Comet 67P

Author

Beth, A., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J.-J., additional, Combi, M. R., additional, De Keyser, J., additional, Fiethe, B., additional, Fuselier, S. A., additional, Galand, M., additional, Gombosi, T. I., additional, Rubin, M., additional, and Sémon, T., additional

Published
2020
Full Text
View/download PDF

29. The Polarimetric and Helioseismic Imager on Solar Orbiter

Author

Solanki, S. K., primary, del Toro Iniesta, J. C., additional, Woch, J., additional, Gandorfer, A., additional, Hirzberger, J., additional, Alvarez-Herrero, A., additional, Appourchaux, T., additional, Martínez Pillet, V., additional, Pérez-Grande, I., additional, Sanchis Kilders, E., additional, Schmidt, W., additional, Gómez Cama, J. M., additional, Michalik, H., additional, Deutsch, W., additional, Fernandez-Rico, G., additional, Grauf, B., additional, Gizon, L., additional, Heerlein, K., additional, Kolleck, M., additional, Lagg, A., additional, Meller, R., additional, Müller, R., additional, Schühle, U., additional, Staub, J., additional, Albert, K., additional, Alvarez Copano, M., additional, Beckmann, U., additional, Bischoff, J., additional, Busse, D., additional, Enge, R., additional, Frahm, S., additional, Germerott, D., additional, Guerrero, L., additional, Löptien, B., additional, Meierdierks, T., additional, Oberdorfer, D., additional, Papagiannaki, I., additional, Ramanath, S., additional, Schou, J., additional, Werner, S., additional, Yang, D., additional, Zerr, A., additional, Bergmann, M., additional, Bochmann, J., additional, Heinrichs, J., additional, Meyer, S., additional, Monecke, M., additional, Müller, M.-F., additional, Sperling, M., additional, Álvarez García, D., additional, Aparicio, B., additional, Balaguer Jiménez, M., additional, Bellot Rubio, L. R., additional, Cobos Carracosa, J. P., additional, Girela, F., additional, Hernández Expósito, D., additional, Herranz, M., additional, Labrousse, P., additional, López Jiménez, A., additional, Orozco Suárez, D., additional, Ramos, J. L., additional, Barandiarán, J., additional, Bastide, L., additional, Campuzano, C., additional, Cebollero, M., additional, Dávila, B., additional, Fernández-Medina, A., additional, García Parejo, P., additional, Garranzo-García, D., additional, Laguna, H., additional, Martín, J. A., additional, Navarro, R., additional, Núñez Peral, A., additional, Royo, M., additional, Sánchez, A., additional, Silva-López, M., additional, Vera, I., additional, Villanueva, J., additional, Fourmond, J.-J., additional, de Galarreta, C. Ruiz, additional, Bouzit, M., additional, Hervier, V., additional, Le Clec’h, J. C., additional, Szwec, N., additional, Chaigneau, M., additional, Buttice, V., additional, Dominguez-Tagle, C., additional, Philippon, A., additional, Boumier, P., additional, Le Cocguen, R., additional, Baranjuk, G., additional, Bell, A., additional, Berkefeld, Th., additional, Baumgartner, J., additional, Heidecke, F., additional, Maue, T., additional, Nakai, E., additional, Scheiffelen, T., additional, Sigwarth, M., additional, Soltau, D., additional, Volkmer, R., additional, Blanco Rodríguez, J., additional, Domingo, V., additional, Ferreres Sabater, A., additional, Gasent Blesa, J. L., additional, Rodríguez Martínez, P., additional, Osorno Caudel, D., additional, Bosch, J., additional, Casas, A., additional, Carmona, M., additional, Herms, A., additional, Roma, D., additional, Alonso, G., additional, Gómez-Sanjuan, A., additional, Piqueras, J., additional, Torralbo, I., additional, Fiethe, B., additional, Guan, Y., additional, Lange, T., additional, Michel, H., additional, Bonet, J. A., additional, Fahmy, S., additional, Müller, D., additional, and Zouganelis, I., additional

Published
2020
Full Text
View/download PDF

30. ALMA and ROSINA detections of phosphorus-bearing molecules: the interstellar thread between star-forming regions and comets

Author

Rivilla, V. M., Drozdovskaya, M. N., Altwegg, K., Caselli, P., BELTRAN SOROLLA, MARIA TERESA, FONTANI, FRANCESCO, van der Tak, F. F. S., CESARONI, Riccardo, Vasyunin, A., Rubin, M., Lique, F., Marinakis, S., TESTI, Leonardo, Rosina Team, Balsiger, H., Berthelier, J. J., de Keyser, J., Fiethe, B., Fuselier, S. A., Gasc, S., Gombosi, T. I., Sémon, T., Tzou, C. -Y., INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), Center for Space and Habitability (CSH), University of Bern, Physikalisches Institut [Bern], Universität Bern [Bern], Max-Planck-Institut für Extraterrestrische Physik (MPE), SRON Netherlands Institute for Space Research (SRON), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Ural Federal University [Ekaterinburg] (UrFU), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), School of Health, Sport and Bioscience (HSB), University of East London (UEL), School of Biological and Chemical Sciences, Queen Mary University of London (QMUL), European Southern Observatory (ESO), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Southwest Research Institute [San Antonio] (SwRI), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, and Astronomy

Subjects
Solar System, PN, Astrochemistry, molecular data, 530 Physics, Comet, SULFUR, FOS: Physical sciences, Astrophysics, 01 natural sciences, Submillimeter Array, ABUNDANCES, CHEMISTRY, Planet, FORMATION [STARS], Bipolar outflow, EXCITATION, 0103 physical sciences, Protostar, POTENTIAL-ENERGY SURFACES, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, ASTROCHEMISTRY, PHOSPHINE, stars: formation, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, 520 Astronomy, comets: general, 67P/CHURYUMOV-GERASIMENKO, PROTOSTELLAR, Astronomy and Astrophysics, MOLECULAR DATA, 620 Engineering, Astrophysics - Astrophysics of Galaxies, ISM: molecules, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, MOLECULES [ISM], Astrophysics of Galaxies (astro-ph.GA), EMISSION, GENERAL [COMETS]
Abstract

To understand how Phosphorus-bearing molecules are formed in star-forming regions, we have analysed ALMA observations of PN and PO towards the massive star-forming region AFGL 5142, combined with a new analysis of the data of the comet 67P/Churyumov-Gerasimenko taken with the ROSINA instrument onboard Rosetta. The ALMA maps show that the emission of PN and PO arises from several spots associated with low-velocity gas with narrow linewidths in the cavity walls of a bipolar outflow. PO is more abundant than PN in most of the spots, with the PO/PN ratio increasing as a function of the distance to the protostar. Our data favor a formation scenario in which shocks sputter phosphorus from the surface of dust grains, and gas-phase photochemistry induced by UV photons from the protostar allows efficient formation of the two species in the cavity walls. Our analysis of the ROSINA data has revealed that PO is the main carrier of P in the comet, with PO/PN>10. Since comets may have delivered a significant amount of prebiotic material to the early Earth, this finding suggests that PO could contribute significantly to the phosphorus reservoir during the dawn of our planet. There is evidence that PO was already in the cometary ices prior to the birth of the Sun, so the chemical budget of the comet might be inherited from the natal environment of the Solar System, which is thought to be a stellar cluster including also massive stars., Accepted in MNRAS (20 pages, 12 figures)

Published
2019
Full Text
View/download PDF

31. Two years with comet 67P/Churyumov-Gerasimenko: H₂O, CO₂, and CO as seen by the ROSINA/RTOF instrument of Rosetta

Author

Hoang, M., Garnier, P., Gourlaouen, H., Lasue, J., Rème, H., Altwegg, Kathrin, Balsiger, Hans, Beth, A., Calmonte, U., Fiethe, B., Galli, André Simon, Gasc, Sébastien, JÄckel, A., Korth, A., Le Roy, L., Mall, U., Rubin, Martin, Sémon, Thierry, Tzou, Chia-Yu, Waite, J. H., and Wurz, Peter

Subjects
520 Astronomy, 620 Engineering
Abstract

Context. The ESA Rosetta mission investigated the environment of comet 67P/Churyumov-Gerasimenko (hereafter 67P) from August 2014 to September 2016. One of the experiments on board the spacecraft, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) included a COmet Pressure Sensor (COPS) and two mass spectrometers to analyze the composition of neutrals and ions, the Reflectron-type Time-Of-Flight mass spectrometer (RTOF), and the Double Focusing Mass Spectrometer (DFMS). Aims. RTOF species detections cover the whole mission. This allows us to study the seasonal evolution of the main volatiles (H₂O, CO₂ , and CO) and their spatial distributions. Methods.We studied the RTOF dataset during the two-year long comet escort phase focusing on the study of H₂O, CO₂, and CO. We also present the detection by RTOF of O₂, the fourth main volatile recorded in the coma of 67P/C-G. This work includes the calibration of spectra and the analysis of the signature of the four volatiles. We present the analysis of the dynamics of the main volatiles and visualize the distribution by projecting our results onto the surface of the nucleus. The temporal and spatial heterogeneities of H₂O, CO₂, and CO are studied over the two years of mission, but the O₂ is only studied over a two-month period. Results. The global outgassing evolution follows the expected asymmetry with respect to perihelion. The CO/CO₂ ratio is not constant through the mission, even though both species appear to originate from the same regions of the nucleus. The outgassing of CO₂ and CO was more pronounced in the southern than in the northern hemisphere, except for the time from August to October 2014. We provide a new and independent estimate of the relative abundance of O₂. Conclusions.We show evidence of a change in molecular ratios throughout the mission.We observe a clear north-south dichotomy in the coma composition, suggesting a composition dichotomy between the outgassing layers of the two hemispheres. Our work indicates that CO₂ and CO are located on the surface of the southern hemisphere as a result of the strong erosion during the previous perihelion. We also report a cyclic occurrence of CO and CO₂ detections in the northern hemisphere. We discuss two scenarios: devolatilization of transported wet dust grains from south to north, and different stratigraphy for the upper layers of the cometary nucleus between the two hemispheres.

Published
2019
Full Text
View/download PDF

32. A flexible and heterogeneous framework for scientific image data processing on-board the Solar Orbiter PHI instrument

Author

Lange, T., Fiethe, B., Guan, Y., Michalik, H., Albert, K., Hirzberger, J., Orozco Suárez, David, Rodríguez Valido, Manuel, Lange, T., Fiethe, B., Guan, Y., Michalik, H., Albert, K., Hirzberger, J., Orozco Suárez, David, and Rodríguez Valido, Manuel

Abstract

Present scientific space instruments generate a high amount of raw data while deep-space missions only have a very limited telemetry rate. Because the computation of the scientific relevant parameters is usually accompanied with the reduction of the data, the processing is desired to be carried out already on-board. To accomplish this, the following paper presents a flexible image processing framework which makes use of a heterogeneous data processing module consisting of a space-grade General Purpose Processor (GPP) as well as two dynamically reconfigurable Field-Programmable Gate Arrays used for hardware acceleration. The flexibility and capabilities of the presented framework are proven by means of three exemplary processing tasks of the Polarimetric and Helioseismic Imager (PHI) on-board Solar Orbiter. © 2019 SPIE.

Published
2019

33. Performance Analysis of the SO/PHI Software Framework for On-board Data Reduction

Author

German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Albert, K., Hirzberger, J., Busse, D., Blanco Rodríguez, J., Duran, J. S. Castellanos, Cobos Carrascosa, Juan Pedro, Fiethe, B., Gandorfer, A., Guan, Y., Kolleck, M., Lagg, A., Lange, T., Michalik, H., Solanki, S. K., Toro, José Carlos del, Woch, J., German Research Foundation, Ministerio de Economía y Competitividad (España), European Commission, Albert, K., Hirzberger, J., Busse, D., Blanco Rodríguez, J., Duran, J. S. Castellanos, Cobos Carrascosa, Juan Pedro, Fiethe, B., Gandorfer, A., Guan, Y., Kolleck, M., Lagg, A., Lange, T., Michalik, H., Solanki, S. K., Toro, José Carlos del, and Woch, J.

Abstract

The Polarimetric and Helioseismic Imager (PHI) is the first deep-space solar spectropolarimeter, on-board the Solar Orbiter (SO) space mission. It faces: stringent requirements on science data accuracy, a dynamic environment, and severe limitations on telemetry volume. SO/PHI overcomes these restrictions through on-board instrument calibration and science data reduction, using dedicated firmware in FPGAs. This contribution analyses the accuracy of a data processing pipeline by comparing the results obtained with SO/PHI hardware to a reference from a ground computer. The results show that for the analyzed pipeline the error introduced by the firmware implementation is well below the requirements of SO/PHI.

Published
2019

34. Two years with comet 67P/Churyumov-Gerasimenko: H2O, CO2, and CO as seen by the ROSINA/RTOF instrument of Rosetta

Author

Hoang, M., primary, Garnier, P., additional, Gourlaouen, H., additional, Lasue, J., additional, Rème, H., additional, Altwegg, K., additional, Balsiger, H., additional, Beth, A., additional, Calmonte, U., additional, Fiethe, B., additional, Galli, A., additional, Gasc, S., additional, Jäckel, A., additional, Korth, A., additional, Le Roy, L., additional, Mall, U., additional, Rubin, M., additional, Sémon, T., additional, Tzou, C.-Y., additional, Waite, J. H., additional, and Wurz, P., additional

Published
2019
Full Text
View/download PDF

36. Comparison of neutral outgassing of comet 67P/Churyumov-Gerasimenko inbound and outbound beyond 3 AU from ROSINA/DFMS

Author

Luspay-Kuti, A., primary, Altwegg, K., additional, Berthelier, J. J., additional, Beth, A., additional, Dhooghe, F., additional, Fiethe, B., additional, Fuselier, S. A., additional, Gombosi, T. I., additional, Hansen, K. C., additional, Hässig, M., additional, Livadiotis, G., additional, Mall, U., additional, Mandt, K. E., additional, Mousis, O., additional, Petrinec, S. M., additional, Rubin, M., additional, Trattner, K. J., additional, Tzou, C.-Y., additional, and Wurz, P., additional

Published
2019
Full Text
View/download PDF

37. Autonomous on-board data processing and instrument calibration software for the SO/PHI

Author

Ministerio de Economía y Competitividad (España), European Commission, German Centre for Air and Space Travel, Albert, K., Hirzberger, J., Busse, D., Lange, T., Kolleck, M., Fiethe, B., Orozco Suárez, David, Woch, J., Schou, J., Blanco Rodríguez, J., Gandorfer, A., Guan, Y., Cobos Carrascosa, Juan Pedro, Hernández Expósito, David, Toro, José Carlos del, Solanki, S. K., Michalik, H., Ministerio de Economía y Competitividad (España), European Commission, German Centre for Air and Space Travel, Albert, K., Hirzberger, J., Busse, D., Lange, T., Kolleck, M., Fiethe, B., Orozco Suárez, David, Woch, J., Schou, J., Blanco Rodríguez, J., Gandorfer, A., Guan, Y., Cobos Carrascosa, Juan Pedro, Hernández Expósito, David, Toro, José Carlos del, Solanki, S. K., and Michalik, H.

Abstract

The extension of on-board data processing capabilities is an attractive option to reduce telemetry for scientific instruments on deep space missions. The challenges that this presents, however, require a comprehensive software system, which operates on the limited resources a data processing unit in space allows. We implemented such a system for the Polarimetric and Helioseismic Imager (PHI) on-board the Solar Orbiter (SO) spacecraft. It ensures autonomous operation to handle long command-response times, easy changing of the processes after new lessons have been learned and meticulous book-keeping of all operations to ensure scientific accuracy. This contribution presents the requirements and main aspects of the software implementation, followed by an example of a task implemented in the software frame, and results from running it on SO/PHI. The presented example shows that the different parts of the software framework work well together, and that the system processes data as we expect. The flexibility of the framework makes it possible to use it as a baseline for future applications with similar needs and limitations as SO/PHI. © 2018 SPIE.

Published
2018

38. 2 years with comet 67P/Churyumov-Gerasimenko: H2O, CO2, CO as seen by ROSINA RTOF

Author

Hoang, M., Garnier, P., Lasue, J., Reme, H., Altwegg, K., Balsiger, H. R., Bieler, A. M., Calmonte, U., CAPRIA, MARIA TERESA, Combi, M. R., De Keyser, J. M., Fiethe, B., Fougere, N., Fuselier, S. A., Galli, A., Gasc, S., Gombosi, T. I., Hansen, K. C., Jäckel, A., Korth, A., Mall, U., MIGLIORINI, Alessandra, Rubin, M., Sémon, T., Tzou, C. Y., Waite, J. H., Jr., Wurz, P., ITA, USA, FRA, DEU, BEL, and CHE

Abstract

The Rosetta space mission investigated comet 67P/Churyumov-Gerasimenko (67P) over two years from August 2014 to September 2016. Onboard the spacecraft, the ROSINA experiment included two mass spectrometers to derive the composition of neutrals and ions, and a COmet Pressure Sensor (COPS) to monitor the density and velocity of the neutrals in the coma. We will here analyse and discuss data from the Reflectron-type Time-Of-Flight instrument during the comet escort phase. The RTOF mass spectrometer possessed a wide mass range and a high temporal resolution (Balsiger et al., 2007). The analysis of 67P/C-G's coma major molecules over the mission showed strong variability of the comet coma's main volatiles concentrations (H2O, CO2, CO) and their relative abundances. The 2 years long Rosetta mission allowed us to observe the seasonal evolution in the atmosphere of 67P, in particular the change occurring during the equinoxes and at perihelion. In this work, we analyze the asymmetry in the outgassing rate before and after the perihelion (13/08/2015), the evolution of abundance ratios through the whole mission, and in particular the behavior of the very volatile CO molecules. Density maps projected on the surface of 67P demonstrate the evolution of the three main coma species after the outbound equinox. We will present first results of our comet nucleus thermal modelling used to simulate the internal structure and temperature evolution of 67P at characteristic surface areas. These results will be compared with the coma composition measurements obtained by ROSINA....

Published
2017

39. First in-situ detection of the cometary ammonium ion NH⁺₄ (protonated ammonia NH₃) in the coma of 67P/C-G near perihelion

Author

Beth, A., Altwegg, Kathrin, Balsiger, Hans, Berthelier, J.-J., Calmonte, Ursina Maria, Combi, M.R., De Keyser, J., Dhooghe, F., Fiethe, B., Fuselier, S.A., Galand, M., Gasc, Sébastien, Gombosi, T.I., Hansen, K.C., Hässig, M., Héritier, K.L., Kopp, Ernest, Le Roy, Léna, Mandt, K.E., Peroy, S., Rubin, Martin, Sémon, Thierry, Tzou, Chia-Yu, and Vigren, E.

Subjects
520 Astronomy, 620 Engineering
Abstract

In this paper, we report the first in situ detection of the ammonium ion NH⁺₄ at 67P/Churyumov–Gerasimenko (67P/C-G) in a cometary coma, using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). Unlike neutral and ion spectrometers onboard previous cometary missions, the ROSINA/DFMS spectrometer, when operated in ion mode, offers the capability to distinguish NH⁺₄ from H₂O⁺ in a cometary coma. We present here the ion data analysis of mass-to-charge ratios 18 and 19 at high spectral resolution and compare the results with an ionospheric model to put these results into context. The model confirms that the ammonium ion NH⁺₄ is one of the most abundant ion species, as predicted, in the coma near perihelion.

Published
2017
Full Text
View/download PDF

40. Ion composition at comet 67P near perihelion : Rosetta observations and model-based interpretation

Author

Heritier, K. L., Altwegg, K., Balsiger, H., Berthelier, J. -J, Beth, A., Bieler, A., Biver, N., Calmonte, U., Combi, M. R., De Keyser, J., Eriksson, Anders I., Fiethe, B., Fougere, N., Fuselier, S. A., Galand, M., Gasc, S., Gombosi, T. I., Hansen, K. C., Hassig, M., Kopp, E., Odelstad, Elias, Rubin, M., Tzou, C. -Y, Vigren, Erik, Vuitton, V., Heritier, K. L., Altwegg, K., Balsiger, H., Berthelier, J. -J, Beth, A., Bieler, A., Biver, N., Calmonte, U., Combi, M. R., De Keyser, J., Eriksson, Anders I., Fiethe, B., Fougere, N., Fuselier, S. A., Galand, M., Gasc, S., Gombosi, T. I., Hansen, K. C., Hassig, M., Kopp, E., Odelstad, Elias, Rubin, M., Tzou, C. -Y, Vigren, Erik, and Vuitton, V.

Abstract

We present the ion composition in the coma of comet 67P with newly detected ion species over the 28-37 u mass range, probed by Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). In summer 2015, the nucleus reached its highest outgassing rate and ion-neutral reactions started to take place at low cometocentric distances. Minor neutrals can efficiently capture protons from the ion population, making the protonated version of these neutrals a major ion species. So far, only NH4+ has been reported at comet 67P. However, there are additional neutral species with proton affinities higher than that of water (besides NH3) that have been detected in the coma of comet 67P: CH3OH, HCN, H2CO and H2S. Their protonated versions have all been detected. Statistics showing the number of detections with respect to the number of scans are presented. The effect of the negative spacecraft potential probed by the Rosetta Plasma Consortium/LAngmuir Probe on ion detection is assessed. An ionospheric model has been developed to assess the different ion density profiles and compare them to the ROSINA/DFMS measurements. It is also used to interpret the ROSINA/DFMS observations when different ion species have similar masses, and their respective densities are not high enough to disentangle them using the ROSINA/DFMS high-resolution mode. The different ion species that have been reported in the coma of 67P are summarized and compared with the ions detected at comet 1P/Halley during the Giotto mission.

Published
2017
Full Text
View/download PDF

41. Evolution of water production of 67P/Churyumov-Gerasimenko

Author

Hansen, Kenneth C., Altwegg, K., Berthelier, J. -J., Bieler, A., Biver, N., Bockelee-Morvan, D., Calmonte, U., Capaccioni, F., Combi, M. R., De Keyser, J., Fiethe, B., Fougere, N., Fuselier, S. A., Gasc, S., Gombosi, T. I., Huang, Z., Le Roy, L., Lee, S., Nilsson, H., Rubin, Martin, Shou, Y., Snodgrass, C., Tenishev, V., Tzou, C.-Y., Wedlund, C. Simon, Toth, Gabor, ROSINA Team, University of Michigan, Ann Arbor, University of Bern, Observatoire de Paris, Istituto Nazionale Astrofisica - Italy, Royal Belgian Institute for Space Aeronomy, TU Braunschweig, University of Texas at San Antonio, Jet Propulsion Laboratory, Swedish Institute of Space Physics, Open University, Department of Radio Science and Engineering, Aalto-yliopisto, and Aalto University

Subjects
individual: 67P/CG [comets], SIMULATION, DUST, CO2, PREPERIHELION, ROSINA, PERIHELION, miscellaneous [methods], ATMOSPHERE, ROSETTA ORBITER, TARGET COMET 67P/CHURYUMOV-GERASIMENKO, general [comets], HALE-BOPP
Abstract

We examine the evolution of the water production of comet 67P/Churyumov-Gerasimenko during the Rosetta mission (2014 June-2016 May) based on in situ and remote sensing measurements made by Rosetta instruments, Earth-based telescopes and through the development of an empirical coma model. The derivation of the empirical model is described and the model is then applied to detrend spacecraft position effects from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) data. The inter-comparison of the instrument data sets shows a high level of consistency and provides insights into the water and dust production. We examine different phases of the orbit, including the early mission (beyond 3.5 au) where the ROSINA water production does not show the expected increase with decreasing heliocentric distance. A second important phase is the period around the inbound equinox, where the peak water production makes a dramatic transition from northern to southern latitudes. During this transition, the waterdistribution is complex, but is driven by rotation and active areas in the north and south. Finally, we consider the perihelion period, where there may be evidence of time dependence in the water production rate. The peak water production, as measured by ROSINA, occurs 18-22 d after perihelion at 3.5 +/- 0.5 x 10(28) water molecules s(-1). We show that the water production is highly correlated with ground-based dust measurements, possibly indicating that several dust parameters are constant during the observed period. Using estimates of the dust/gas ratio, we use our measured water production rate to calculate a uniform surface loss of 2-4 m during the current perihelion passage.

Published
2016

42. Isotopic composition of CO2in the coma of 67P/Churyumov-Gerasimenko measured with ROSINA/DFMS

Author

Hässig, M., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J. J., additional, Bieler, A., additional, Calmonte, U., additional, Dhooghe, F., additional, Fiethe, B., additional, Fuselier, S. A., additional, Gasc, S., additional, Gombosi, T. I., additional, Le Roy, L., additional, Luspay-Kuti, A., additional, Mandt, K., additional, Rubin, M., additional, Tzou, C.-Y., additional, Wampfler, S. F., additional, and Wurz, P., additional

Published
2017
Full Text
View/download PDF

43. Ion composition at comet 67P near perihelion: Rosetta observations and model-based interpretation

Author

Heritier, K. L., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J.-J., additional, Beth, A., additional, Bieler, A., additional, Biver, N., additional, Calmonte, U., additional, Combi, M. R., additional, De Keyser, J., additional, Eriksson, A. I., additional, Fiethe, B., additional, Fougere, N., additional, Fuselier, S. A., additional, Galand, M., additional, Gasc, S., additional, Gombosi, T. I., additional, Hansen, K. C., additional, Hassig, M., additional, Kopp, E., additional, Odelstad, E., additional, Rubin, M., additional, Tzou, C.-Y., additional, Vigren, E., additional, and Vuitton, V., additional

Published
2017
Full Text
View/download PDF

44. Sulphur isotope mass-independent fractionation observed in comet 67P/Churyumov–Gerasimenko by Rosetta/ROSINA

Author

Calmonte, U, primary, Altwegg, K, additional, Balsiger, H, additional, Berthelier, J-J, additional, Bieler, A, additional, De Keyser, J, additional, Fiethe, B, additional, Fuselier, S A, additional, Gasc, S, additional, Gombosi, T I, additional, Le Roy, L, additional, Rubin, M, additional, Sémon, T, additional, Tzou, C-Y, additional, and Wampfler, S F, additional

Published
2017
Full Text
View/download PDF

45. Evidence for depletion of heavy silicon isotopes at comet 67P/Churyumov-Gerasimenko

Author

Rubin, M., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J.-J., additional, Bieler, A., additional, Calmonte, U., additional, Combi, M., additional, De Keyser, J., additional, Engrand, C., additional, Fiethe, B., additional, Fuselier, S. A., additional, Gasc, S., additional, Gombosi, T. I., additional, Hansen, K. C., additional, Hässig, M., additional, Le Roy, L., additional, Mezger, K., additional, Tzou, C.-Y., additional, Wampfler, S. F., additional, and Wurz, P., additional

Published
2017
Full Text
View/download PDF

46. The heterogeneous coma of comet 67P/Churyumov-Gerasimenko as seen by ROSINA: H2O, CO2, and CO from September 2014 to February 2016

Author

Hoang, M., primary, Altwegg, K., additional, Balsiger, H., additional, Beth, A., additional, Bieler, A., additional, Calmonte, U., additional, Combi, M. R., additional, De Keyser, J., additional, Fiethe, B., additional, Fougere, N., additional, Fuselier, S. A., additional, Galli, A., additional, Garnier, P., additional, Gasc, S., additional, Gombosi, T., additional, Hansen, K. C., additional, Jäckel, A., additional, Korth, A., additional, Lasue, J., additional, Le Roy, L., additional, Mall, U., additional, Rème, H., additional, Rubin, M., additional, Sémon, T., additional, Toublanc, D., additional, Tzou, C.-Y., additional, Waite, J. H., additional, and Wurz, P., additional

Published
2017
Full Text
View/download PDF

47. First in-situ detection of the cometary ammonium ion NH$_4^{+}$ (protonated ammonia NH 3 ) in the coma of 67P/C-G near perihelion

Author

Beth, A., primary, Altwegg, K., additional, Balsiger, H., additional, Berthelier, J.-J., additional, Calmonte, U., additional, Combi, M.R., additional, De Keyser, J., additional, Dhooghe, F., additional, Fiethe, B., additional, Fuselier, S.A., additional, Galand, M., additional, Gasc, S., additional, Gombosi, T.I., additional, Hansen, K.C., additional, Hässig, M., additional, Héritier, K.L., additional, Kopp, E., additional, Le Roy, L., additional, Mandt, K.E., additional, Peroy, S., additional, Rubin, M., additional, Sémon, T., additional, Tzou, C.-Y., additional, and Vigren, E., additional

Published
2017
Full Text
View/download PDF

48. Ion chemistry in the coma of comet 67P near perihelion

Author

Fuselier, S. A., Altwegg, K., Balsiger, H., Berthelier, J. J., Beth, A., Bieler, A., Briois, C., Broiles, T. W., Burch, J. L., Calmonte, U., Cessateur, G., Combi, M., De Keyser, J., Fiethe, B., Galand, M., Gasc, S., Gombosi, T. I., Gunell, H., Hansen, K. C., Hassig, M., Heritier, K. L., Korth, A., Le Roy, L., Luspay-Kuti, A., Mall, U., Mandt, K. E., Petrinec, S. M., Reme, H., Rinaldi, M., Rubin, M., Semon, T., Trattner, K. J., Tzou, C. -Y, Vigren, Erik, Waite, J. H., Wurz, P., Fuselier, S. A., Altwegg, K., Balsiger, H., Berthelier, J. J., Beth, A., Bieler, A., Briois, C., Broiles, T. W., Burch, J. L., Calmonte, U., Cessateur, G., Combi, M., De Keyser, J., Fiethe, B., Galand, M., Gasc, S., Gombosi, T. I., Gunell, H., Hansen, K. C., Hassig, M., Heritier, K. L., Korth, A., Le Roy, L., Luspay-Kuti, A., Mall, U., Mandt, K. E., Petrinec, S. M., Reme, H., Rinaldi, M., Rubin, M., Semon, T., Trattner, K. J., Tzou, C. -Y, Vigren, Erik, Waite, J. H., and Wurz, P.

Abstract

The coma and the comet-solar wind interaction of comet 67P/Churyumov-Gerasimenko changed dramatically from the initial Rosetta spacecraft encounter in 2014 August through perihelion in 2015 August. Just before equinox (at 1.6 au from the Sun), the solar wind signal disappeared and two regions of different cometary ion characteristics were observed. These 'outer' and 'inner' regions have cometary ion characteristics similar to outside and inside the ion pileup region observed during the Giotto approach to comet 1P/Halley. Rosetta/Double-Focusing Mass Spectrometer ion mass spectrometer observations are used here to investigate the H3O+/H2O+ ratio in the outer and inner regions at 67P/Churyumov-Gerasimenko. The H3O+/H2O+ ratio and the H3O+ signal are observed to increase in the transition from the outer to the inner region and the H3O+ signal appears to be weakly correlated with cometary ion energy. These ion composition changes are similar to the ones observed during the 1P/Halley flyby. Modelling is used to determine the importance of neutral composition and transport of neutrals and ions away from the nucleus. This modelling demonstrates that changes in the H3O+/H2O+ ratio appear to be driven largely by transport properties and only weakly by neutral composition in the coma.

Published
2016
Full Text
View/download PDF

49. First in situ detection of the cometary ammonium ion NH4+ (protonated ammonia NH3) in the coma of 67P/C-G near perihelion

Author

Beth, A., Altwegg, K., Balsiger, H., Berthelier, J. -J, Calmonte, U., Combi, M. R., De Keyser, J., Dhooghe, F., Fiethe, B., Fuselier, S. A., Galand, M., Gasc, S., Gombosi, T. I., Hansen, K. C., Hassig, M., Heritier, K. L., Kopp, E., Le Roy, L., Mandt, K. E., Peroy, S., Rubin, M., Semon, T., Tzou, C. -Y, Vigren, Erik, Beth, A., Altwegg, K., Balsiger, H., Berthelier, J. -J, Calmonte, U., Combi, M. R., De Keyser, J., Dhooghe, F., Fiethe, B., Fuselier, S. A., Galand, M., Gasc, S., Gombosi, T. I., Hansen, K. C., Hassig, M., Heritier, K. L., Kopp, E., Le Roy, L., Mandt, K. E., Peroy, S., Rubin, M., Semon, T., Tzou, C. -Y, and Vigren, Erik

Abstract

In this paper, we report the first in situ detection of the ammonium ion NH4+ at 67P/Churyumov-Gerasimenko (67P/C-G) in a cometary coma, using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). Unlike neutral and ion spectrometers onboard previous cometary missions, the ROSINA/DFMS spectrometer, when operated in ion mode, offers the capability to distinguish NH4+ from H2O+ in a cometary coma. We present here the ion data analysis of mass-to-charge ratios 18 and 19 at high spectral resolution and compare the results with an ionospheric model to put these results into context. The model confirms that the ammonium ion NH4+ is one of the most abundant ion species, as predicted, in the coma near perihelion.

Published
2016
Full Text
View/download PDF

50. Photochemistry of O(1D) and O(1S) lines in the coma of 67P/Churyumov-Gerasimenko

Author

European Geosciences Union (EGU) General Assembly 2016 (April 17-22, 2016: Vienna, Austria), Cessateur, G., De Keyser, J, Maggiolo, Romain, Gibbons, Andrew, Gronoff, G., Gunell, H., Dhooghe, F., Loreau, Jérôme, Vaeck, Nathalie, Altwegg, K., Bieler, A., Briois, C., Calmonte, U., Combi, M. R., Fiethe, B., Fuselier, S. A., Gombosi, T. I., Hassig, M., Le Roy, L., Neefs, E., Rubin, M., Sémon, T., European Geosciences Union (EGU) General Assembly 2016 (April 17-22, 2016: Vienna, Austria), Cessateur, G., De Keyser, J, Maggiolo, Romain, Gibbons, Andrew, Gronoff, G., Gunell, H., Dhooghe, F., Loreau, Jérôme, Vaeck, Nathalie, Altwegg, K., Bieler, A., Briois, C., Calmonte, U., Combi, M. R., Fiethe, B., Fuselier, S. A., Gombosi, T. I., Hassig, M., Le Roy, L., Neefs, E., Rubin, M., and Sémon, T.

Abstract

info:eu-repo/semantics/nonPublished

Published
2016

Catalog

Books, media, physical & digital resources
See catalog results