| 1. |
- Kueppers, Michael, et al.
(author)
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Triple F-a comet nucleus sample return mission
- 2009
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In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:3, s. 809-847
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Journal article (peer-reviewed)abstract
- The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA's Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three sample cores of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-and-go sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.
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| 2. |
- Linnartz, H., et al.
(author)
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C-60(+) as a diffuse interstellar band carrier; a spectroscopic story in 6 acts
- 2020
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In: Journal of Molecular Spectroscopy. - : Elsevier BV. - 0022-2852 .- 1096-083X. ; 367
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Journal article (peer-reviewed)abstract
- In 2019 it was exactly 100 years ago that the first two DIBs, diffuse interstellar bands, were discovered by Mary Lea Heger. Today some 500 + DIBs are known. In numerous observational, modelling and laboratory studies, efforts have been made to identify the carriers of these absorption features that are observed in the light of reddened stars crossing diffuse and translucent clouds. Despite several claims over the years that specific DIBs could be assigned to specific species, not one of these withstood dedicated follow-up studies. An exception is C-60(+). In 2015, Campbell et al. showed that two strong bands, recorded in the laboratory around 960 nm, coincided precisely with known DIBs and in follow-up studies three more matches between C-60(+) transitions and new observational DIB studies were claimed. Over the last four years the evidence for C-60(+) as the first identified DIB carrier - including new laboratory data and Hubble Space Telescope observations - has been accumulating, but not all open issues have been solved yet. This article summarizes 6 spectroscopic achievements that sequentially contributed to what seems to become the first DIB story with a happy end.
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| 3. |
- Sollerman, J., et al.
(author)
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Diffuse Interstellar Bands in NGC 1448
- 2005
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 429, s. 559-567
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Journal article (peer-reviewed)abstract
- We present spectroscopic VLT/UVES observations of two emerging supernovae, the Type Ia SN 2001el and the Type II SN 2003hn, in the spiral galaxy NGC 1448. Our high resolution and high signal-to-noise spectra display atomic lines of Ca II, Na I, Ti II and K I in the host galaxy. In the line of sight towards SN 2001el, we also detect over a dozen diffuse interstellar bands (DIBs) within NGC 1448. These DIBs have strengths comparable to low reddening galactic lines of sight, albeit with some variations. In particular, a good match is found with the line of sight towards the σ type diffuse cloud (HD 144217). The DIBs towards SN 2003hn are significantly weaker, and this line of sight has also lower sodium column density. The DIB central velocities show that the DIBs towards SN 2001el are closely related to the strongest interstellar Ca II and Na I components, indicating that the DIBs are preferentially produced in the same cloud. The ratio of the λ 5797 and λ 5780 DIB strengths (r ˜ 0.14) suggests a rather strong UV field in the DIB environment towards SN 2001el. We also note that the extinction estimates obtained from the sodium lines using multiple line fitting agree with reddening estimates based on the colors of the Type Ia SN 2001el. Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO Programmes 67.D-0227 and 71.D-0033). Table \ref{tb:ISfit} and Figs. \ref{fig:IS_MW} and \ref{fig:6284} are only available in electronic form at http://www.edpsciences.org
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| 4. |
- Baqué, Mickael, et al.
(author)
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Biosignature stability in space enables their use for life detection on Mars
- 2022
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In: Science Advances. - : NLM (Medline). - 2375-2548. ; 8:36
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Journal article (peer-reviewed)abstract
- Two rover missions to Mars aim to detect biomolecules as a sign of extinct or extant life with, among other instruments, Raman spectrometers. However, there are many unknowns about the stability of Raman-detectable biomolecules in the martian environment, clouding the interpretation of the results. To quantify Raman-detectable biomolecule stability, we exposed seven biomolecules for 469 days to a simulated martian environment outside the International Space Station. Ultraviolet radiation (UVR) strongly changed the Raman spectra signals, but only minor change was observed when samples were shielded from UVR. These findings provide support for Mars mission operations searching for biosignatures in the subsurface. This experiment demonstrates the detectability of biomolecules by Raman spectroscopy in Mars regolith analogs after space exposure and lays the groundwork for a consolidated space-proven database of spectroscopy biosignatures in targeted environments.
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| 5. |
- Jones, HRA, et al.
(author)
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Status of the physics of substellar objects project
- 2005
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In: Astronomical Notes - Astronomische Nachrichten. - : Wiley. - 0004-6337. ; 326:10, s. 920-924
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Journal article (peer-reviewed)abstract
- A full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, hundreds of brown dwarfs and extrasolar planets have been discovered. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the theoretical understanding of cool atmospheres. The reliable determination of mass, abundances, gravities and temperatures is not yet possible. The key problem is that substellar objects emit their observable radiation in the infrared region of the spectrum where our knowledge of atomic, molecular and line broadening data is poor. Here we report on the status of our PoSSO (Physics of SubStellar Objects) project. In order to understand brown dwarfs and extrasolar planets increasing more like those in our solar system, we are studying a wide range of processes. Here we give an update on the project and sketch an outline of atoms, molecules and processes requiring study.
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| 6. |
- Lammer, H., et al.
(author)
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What makes a planet habitable?
- 2009
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In: The Astronomy and Astrophysics Review. - : Springer Science and Business Media LLC. - 0935-4956 .- 1432-0754. ; 17:2, s. 181-249
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Research review (peer-reviewed)abstract
- This work reviews factors which are important for the evolution of habitable Earth-like planets such as the effects of the host star dependent radiation and particle fluxes on the evolution of atmospheres and initial water inventories. We discuss the geodynamical and geophysical environments which are necessary for planets where plate tectonics remain active over geological time scales and for planets which evolve to one-plate planets. The discoveries of methane-ethane surface lakes on Saturn's large moon Titan, subsurface water oceans or reservoirs inside the moons of Solar System gas giants such as Europa, Ganymede, Titan and Enceladus and more than 335 exoplanets, indicate that the classical definition of the habitable zone concept neglects more exotic habitats and may fail to be adequate for stars which are different from our Sun. A classification of four habitat types is proposed. Class I habitats represent bodies on which stellar and geophysical conditions allow Earth-analog planets to evolve so that complex multi-cellular life forms may originate. Class II habitats includes bodies on which life may evolve but due to stellar and geophysical conditions that are different from the class I habitats, the planets rather evolve toward Venus- or Mars-type worlds where complex life-forms may not develop. Class III habitats are planetary bodies where subsurface water oceans exist which interact directly with a silicate-rich core, while class IV habitats have liquid water layers between two ice layers, or liquids above ice. Furthermore, we discuss from the present viewpoint how life may have originated on early Earth, the possibilities that life may evolve on such Earth-like bodies and how future space missions may discover manifestations of extraterrestrial life.
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