- ID:
- ivo://CDS.VizieR/J/A+A/654/A143
- Title:
- Ion and femtosecond laser irradiation spectra
- Short Name:
- J/A+A/654/A143
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Space weathering is a process that changes the surface of airless planetary bodies. Prime space weathering agents are solar wind irradiation and micrometeoroid bombardment. These processes alter planetary reflectance spectra and often modify their compositional diagnostic features. In this work we focused on simulating and comparing the spectral changes caused by solar wind irradiation and by micrometeoroid bombardment to gain a better understanding of these individual space weathering processes. We used olivine and pyroxene pellets as proxies for planetary materials. To simulate solar wind irradiation we used hydrogen, helium, and argon ions with energies from 5 to 40keV and fluences of up to 10^18^particles/cm^2^. To simulate micrometeoroid bombardment we used individual femtosecond laser pulses. We analysed the corresponding evolution of different spectral parameters, which we determined by applying the Modified Gaussian Model, and we also conducted principal component analysis. The original mineralogy of the surface influences the spectral evolution more than the weathering agent, as seen from the diverse evolution of the spectral slope of olivine and pyroxene upon irradiation. The spectral slope changes seen in olivine are consistent with observations of A-type asteroids, while the moderate to no slope changes observed in pyroxene are consistent with asteroid (4) Vesta. We also observed some differences in the spectral effects induced by the two weathering agents. Ions simulating solar wind have a smaller influence on longer wavelengths of the spectra than laser irradiation simulating micrometeoroid impacts. This is most likely due to the different penetration depths of ions and laser pulses. Our results suggest that in some instances it might be possible to distinguish between the contributions of the two agents on a weathered surface.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+AS/103/57
- Title:
- Ion-atom collisions in Sun atmosphere
- Short Name:
- J/A+AS/103/57
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJ/761/16
- Title:
- IR colors of the Sun from Line-Depth Ratios
- Short Name:
- J/ApJ/761/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Solar infrared colors provide powerful constraints on the stellar effective temperature scale, but they must be measured with both accuracy and precision in order to do so. We fulfill this requirement by using line-depth ratios to derive in a model-independent way the infrared colors of the Sun, and we use the latter to test the zero point of the Casagrande et al. (Cat. J/A+A/512/A54) effective temperature scale, confirming its accuracy. Solar colors in the widely used Two Micron All Sky Survey (2MASS) JHK_s_ and WISE W1-4 systems are provided: (V-J)_{sun}_=1.198, (V-H)_{sun}_=1.484, (V-K_s_)_{sun}_=1.560, (J-H)_{sun}_=0.286, (J-K_s_)_{sun}_=0.362, (H-K_s_)_{sun}_=0.076, (V-W1)_{sun}_=1.608, (V-W2)_{sun}_=1.563, (V-W3)_{sun}_=1.552, and (V-W4)_{sun}_=1.604. A cross-check of the effective temperatures derived implementing 2MASS or WISE magnitudes in the infrared flux method confirms that the absolute calibration of the two systems agrees within the errors, possibly suggesting a 1% offset between the two, thus validating extant near- and mid-infrared absolute calibrations. While 2MASS magnitudes are usually well suited to derive T_eff_, we find that a number of bright, solar-like stars exhibit anomalous WISE colors. In most cases, this effect is spurious and can be attributed to lower-quality measurements, although for a couple of objects (3%+/-2% of the total sample) it might be real, and may hint at the presence of warm/hot debris disks.
- ID:
- ivo://CDS.VizieR/J/ApJS/241/31
- Title:
- Kink oscillations of solar coronal loops
- Short Name:
- J/ApJS/241/31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of kink oscillations of solar coronal loops, which spans during almost all of solar cycle 24, is presented. The catalog is based on the observations made in the extreme ultraviolet band at 171{AA} with Solar Dynamics Observatory/Atmospheric Imaging Assembly and includes parameters of 223 oscillating loops in 96 oscillation events. The catalog provides the information about the oscillation locations, time, and dates of the events, associated flare, initial displacement, oscillation period, exponential damping time, and apparent amplitude. The vast majority of the oscillation detections, 84%, were made in the loops situated near or off the solar limb. The oscillation periods are found to range from 1 to 28 minutes, with 74% of the events that have the period in the range of 2-10 minutes. About 90% of the oscillations have the apparent amplitude in the range of 1-10Mm. The oscillating loop lengths are 70-600 Mm. The typical apparent amplitude is about 1% of the loop length. The oscillation period scales linearly with the loop length, and the damping time scales linearly with the period, which confirm previous findings. The oscillation quality factor scales with the amplitude to the power of minus 0.7. No statistically significant evidence of correlation was found between both the oscillation period and the mean sunspot number, and the loop length and mean sunspot number. The catalog provides the research community with the foundation for the further statistical study of kink oscillations and their use for coronal seismology.
- ID:
- ivo://CDS.VizieR/J/A+AS/113/71
- Title:
- Lines in the infrared solar spectrum
- Short Name:
- J/A+AS/113/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We list 603 spectral lines between 1.0, 1.8um that are judged to be relatively unblended from a visual inspection of spectra of the quiet sun. Much of the atomic data of relevance to studies of solar and stellar magnetism, convection and atmospheric structure are also provided. Particular attention is paid to blending by telluric lines. We determine the level of blending both in the presence and the absence of telluric lines. We also describe how telluric blends may be removed from spectra with high spectral resolution.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/34
- Title:
- Magnetic wave activity observed by Voyager 1 & 2
- Short Name:
- J/ApJS/237/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In our companion papers (Hollick+ 2018ApJ...863...75H and 2018ApJ...863...76H) we analyze 637 intervals of magnetic wave activity observed by the Voyager 1 and 2 spacecraft from its launch in 1977 through the end of 1990. We argue that these waves originate from cyclotron resonance with newborn interstellar pickup He+ and H+. As the list of wave events is long and potentially useful to other researchers, we take this opportunity to list the times of those wave events here, along with their heliocentric location, ellipticity (often referred to as polarization), and whether thermal ion data is available from the PLS instrument. A brief overview of the analysis contained within the companion papers is also provided.
- ID:
- ivo://CDS.VizieR/J/ApJ/752/126
- Title:
- Modeling the magnetic field in the solar corona
- Short Name:
- J/ApJ/752/126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al (2006SoPh..233..215W). We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.
- ID:
- ivo://CDS.VizieR/J/ApJS/169/439
- Title:
- Models of solar magnetic structures
- Short Name:
- J/ApJS/169/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents semiempirical models of various solar magnetic structures, extending from the photosphere to the chromosphere. The models have been derived from non-LTE inversions of high-resolution spectropolarimetric observations of four CaII and FeI lines. The observed targets are dark and bright components of a sunspot umbra; dark and bright components of a sunspot penumbra; a canopy between two sunspots; a facula; and a network element. These models may be employed, e.g., to compute realistic synthetic Stokes spectra of photospheric and chromospheric lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/707/482
- Title:
- Models of the solar atmosphere. III.
- Short Name:
- J/ApJ/707/482
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Semiempirical atmospheric models of solar surface features as observed at moderate resolution are useful tools for understanding the observed solar spectral irradiance variations. Paper I described a set of models constructed to reproduce the observed radiance spectrum for solar surface features at ~2 arcsec resolution that constitute an average over small-scale features such as granulation. Paper II showed that a revision of previous models of low-chromospheric inter-network regions explains the observed infrared CO lines in addition to the UV and radio continuum from submillimeter to centimetric wavelengths. The present paper (1) shows that the CaII H and K line wing observations are also explained by the new quiet-Sun-composite model, (2) introduces new low-chromospheric models of magnetic features that follow the ideas in Paper II (Fontenla et al. 2007ApJ...667.1243F), (3) introduces new upper chromospheric structures for all quiet-Sun and active-region models, and (4) shows how the new set of models explains EUV/FUV observations of spectral radiance and irradiance. This paper also discusses the chromospheric radiative-loss estimates in each of the magnetic features. The new set of models provides a basis for the spectral irradiance synthesis at EUV/FUV wavelengths based on the features observed on the solar surface.
- ID:
- ivo://CDS.VizieR/J/A+A/601/A109
- Title:
- Monthly numbers of sunspot groups 1749-1996
- Short Name:
- J/A+A/601/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Sunspot number series are composed from observations of hundreds of different observers that requires careful normalization of the observers to the standard conditions. Here we present a new normalized series of the number of sunspot groups for the period 1749-1996. The reconstruction is based on the active day fraction (ADF) method, which is slightly updated with respect to the previous works, and a revised database of sunspot group observations. Stability of some key solar observers has been evaluated against the composite series. The Royal Greenwich Observatory dataset appears fairly stable since the 1890s but is about 10% too low before that. A declining trend of 10-15% in the quality of Wolfer's observation is found between the 1880s and 1920s, suggesting that using him as the reference observer may lead to additional uncertainties. Wolf (small telescope) appears fairly stable between the 1860s and 1890s, without any obvious trend. The new reconstruction reflects the centennial variability of solar activity as evaluated using the singular spectrum analysis method. It depicts a highly significant feature of the Modern grand maximum of solar activity in the second half of the 20th century, being a factor 1.33-1.77 higher than during the 18-19th centuries. The new series of the sunspot group numbers with monthly and annual resolution, available also in the electronic format, is provided forming a basis for new studies of the solar variability and solar dynamo for the last 250 years.
