adsabs/AstroCLIMB huggingface dataset:
Paper: Bridging High-density Electron Beam Coronal Transport and Deep Chromospheric Heating in Stellar Flares
Authors: Adam F. Kowalski
Figure caption: (a) Nonthermal electron number flux distribution and time-averaged electron number flux distribution with plasma wave interactions, reproduced from Figure 4 of K12. (b) The initial heating rate from Coulomb collisions in our RADYN M-dwarf model chromosphere. (c) The initial Coulomb heating rate in the M-dwarf chromosphere for several power-law indices and low-energy cutoffs compared to the K12 heating rate in panel (b). (d) Beam-heating calculations (top panel) for various magnetic field convergence distributions in the chromosphere (bottom panel). The initial gas temperature stratification of the lower M‐dwarf atmosphere is shown as dashed curves in panels (b), (c), and (d).
Paper: Bridging High-density Electron Beam Coronal Transport and Deep Chromospheric Heating in Stellar Flares
Authors: Adam F. Kowalski
Figure caption: High-cadence (Δt = 1.1 s) ULTRACAM photometry in the NBF4170 (λ cen = 4170 Å) narrowband continuum filter during two sequential flare events (IF1 and IF3) on the dM4.5e star YZ CMi. The photometry is normalized to 1.0 during quiescence, and the statistical photometry errors are plotted but are small on this scale. The flux-calibrated, quiescent-subtracted NBF4170 and the RC#1 (λ cen = 6010 Å) data are converted to filter ratios. We solve for the optical color temperatures (T col), which are referred to as FcolorR in the study of these events in Kowalski et al. (2016a). Representative systematic uncertainties on the color temperatures are indicated as ﹩{}_{-550}^{+600}﹩ K and are obtained from the uncertainties in the absolute flux calibration. Note that detailed comparisons of spectra to ULTRACAM filter ratios in smaller-amplitude flares that occurred later in these observations have revealed that values of TFcolorR ≈10,000 K are systematically smaller by ≈2000 K compared to the color temperatures that are fit to the blue-optical spectral range at λ = 4000–4800 Å (see Kowalski et al. 2016a for details about the data, flare colors, and error analysis).
Paper: New Constraints for Supernova Models from Presolar Silicon Carbide X Grains with Very High 26Al/27Al Ratios
Authors: Peter Hoppe, Jan Leitner, Marco Pignatari, Sachiko Amari
Figure caption: Left: profiles of 12C/13C and 26Al/27Al ratios in the interior of a 25 M ⊙ SN according to models 25T-H, 25T-H5, and 25T-H10 of Pignatari et al. (2015). The yellow and blue areas denote the C/Si and O/nova zones, respectively. Note that the Si zone (below the C/Si zone) provides lots of 28Si, required to account for the isotopically light Si of X grains; other isotopic ratios are only marginally affected by the admixture of matter from this zone. The ranges of C and Al isotopic ratios of X grains with high initial 26Al/27Al ratios are indicated by horizontal bars. The two vertical dotted black lines represent the mass coordinates between which the ranges of C and Al isotopic compositions of X grains can be simultaneously reproduced by model 25T-H10 (see Figure 1). Right: profiles of 12C/13C and 26Al/27Al ratios in the interior of a 15 M ⊙ SN according to model s15a28c of Rauscher et al. (2002). The eight SN zones are named according to the most abundant elements in the respective zone. The ranges of C and Al isotopic ratios of X grains with high 26Al/27Al ratios are indicated by horizontal bars.
Paper: Bridging High-density Electron Beam Coronal Transport and Deep Chromospheric Heating in Stellar Flares
Authors: Adam F. Kowalski
Figure caption: (a) The atmospheric gas temperature response to electron beam-heating models with E  c  = 85 keV at t = 1 s after injection into a model M-dwarf atmosphere. The vertical dashed lines indicate the column masses at which τ = 0.95 occur in the continuum wavelength at λ = 3615 Å. The preflare gas temperature (t  =  0 s) is shown for comparison. (b) The variation of the optical depth at λ = 4170 Å exhibits marked differences between the mF12-85-3 and mF13-85-3 models at t = 1 s in their respective evolution. The gas temperature of the mF13-85-3 model is reproduced from panel (a). The contribution function (C  I ) to the emergent intensity at three continuum wavelengths in the mF13-85-3 model at t = 1 s is displayed in units of erg cm−2 s−1 Å−1 s.r.−1 (unit log10 col mass)−1 on a linear scale with arbitrary peak normalization.
Paper: Bridging High-density Electron Beam Coronal Transport and Deep Chromospheric Heating in Stellar Flares
Authors: Adam F. Kowalski
Figure caption: A hypothetical, two-step modular approach to modeling the time-dependent treatments of the K12 beam-plasma evolution in the corona and the radiative-hydrodynamic response of the lower atmosphere of a loop within a flare arcade. (a) Illustrated time evolution of a reconnected field line retracting downward toward the relaxed, previously reconnected loops (dashed loop and below). A hypothetical nonthermal electron path in the (preaccelerated) power-law beam experiences additional acceleration to E > 100 keV through nonlinear wave–wave interactions as it is trapped in this region. The illustrated geometries and particle paths (neither to scale) are largely inspired by the models of Aschwanden (2004) and Egedal et al. (2015). (b) Radiative-hydrodynamic modeling of the evolution of a semicircular loop with field-aligned flows and plane-parallel radiative transfer in response to heating by the K12 beam and a return current electric field, including any magnetic field convergence in the low atmosphere. Note that the Aschwanden (2004) prescription for pulsed nonthermal injection actually occurs during the retraction phase (panel a), but current RHD modeling capabilities with nonthermal particles cannot yet include the retraction of the magnetic field; a short-duration constant flux injection of a K12 beam is likely sufficient for many purposes.
Paper: New Constraints for Supernova Models from Presolar Silicon Carbide X Grains with Very High 26Al/27Al Ratios
Authors: Peter Hoppe, Jan Leitner, Marco Pignatari, Sachiko Amari
Figure caption: The 26Al/27Al and 12C/13C ratios of six SiC X grains from this study (red circles) along with data from the literature (light blue diamonds and purple squares; see a compilation of data in Stephan et al. 2021). Errors are 1σ. The C and Al data of grains from this study and two grains from the literature with 26Al/27Al ratios of ∼0.6 (Amari et al. 1992 Gyngard et al. 2018) are well matched by SN model 25T-H10 of Pignatari et al. (2015) at mass coordinate 6.93–6.95 M ⊙ (the blue solid line which connects the nine data points from the model in this mass range).
Paper: New Constraints for Supernova Models from Presolar Silicon Carbide X Grains with Very High 26Al/27Al Ratios
Authors: Peter Hoppe, Jan Leitner, Marco Pignatari, Sachiko Amari
Figure caption: SEM image and NanoSIMS ion images of 24Mg+, 26Mg+, 27Al+, 28Si+, and 26Mg+/27Al+ of SiC X grain KJF-X5. The scale bar shown in the 24Mg+ image applies to all images. As it can be seen from the two Mg ion images in the upper row, Mg is essentially monoisotopic 26Mg. Magnesium-26 enhancements are well correlated with 27Al abundances. This is clear evidence for 26Al decay with an initial 26Al/27Al ratio of ∼0.78. The white outline indicates the area used for the calculation of 26Al/27Al.
Paper: New Constraints for Supernova Models from Presolar Silicon Carbide X Grains with Very High 26Al/27Al Ratios
Authors: Peter Hoppe, Jan Leitner, Marco Pignatari, Sachiko Amari
Figure caption: Histogram of initial 26Al/27Al ratios of six SiC X grains from this study (red) and of X grains from the literature (see a compilation of data in Stephan et al. 2021). Bin size is 0.02. All our data plot above 26Al/27Al > ∼ 0.6 while only ∼2% of X grains from the literature fall in this range.
Paper: High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters
Authors: Michelle Vick, Yubo Su, Dong Lai
Figure caption: The intermediate angles θ sb,i, θ lb,i, and θ sl,i (recorded at the end of integrations such as those shown in the left panel of Figure 2) as a function of the initial binary inclination θ lb,0. The results for integration times of 5 Myr, 10 Myr, and 15 Myr are shown. The black dashed lines illustrate the approximate analytical model given by Equations (2)–(4)). Good agreement is expected except when θ lb,0 is close to 0°, 90°, or 180°.
Paper: High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters
Authors: Michelle Vick, Yubo Su, Dong Lai
Figure caption: Left panel: the evolution of various spin and orbit angles during the disk dissipation stage, obtained by integrating Equations (A5), (A9), and (A15). The initial conditions are θ sl = 0° and θ lb,0 = θ sb,0 = 100°. The integration is run for 10τ d = 10 Myr, where τ d = Myr is the characteristic disk lifetime. Right panel: the continued evolution of the relevant spin and orbital angular momentum vectors throughout the migration of a giant planet. The plot is truncated before the planet’s orbit circularizes fully. This panel also includes θ jb, the angle between J =  S  ⋆ +  L  and  L  b. The eccentricity of the binary companion is e b = 0.6, and at the onset of ZLK oscillations (t i), θ lb,i = 105.°1 and θ sl,i = 50.°43.  At t − t i ≈ 10 Myr, after multiple ZLK cycles, the orbital eccentricity is excited to near-unity, and chaotic dynamical tides rapidly shrink the orbit. Beyond this point, the orbital evolution of the planet is decoupled from the influence of the stellar companion, and the spin and orbit angles continue to behave in a similar way as the planetary orbit circularizes over another few tens of Myr.
Paper: High-eccentricity Migration with Disk-induced Spin–Orbit Misalignment: A Preference for Perpendicular Hot Jupiters
Authors: Michelle Vick, Yubo Su, Dong Lai
Figure caption: The proposed HJ formation scenario. Initially, in panel (1), a proto-HJ (red) and a protoplanetary disk (gray) are both orbiting their host star, which also has a binary companion (blue). The stellar spin angular momentum and binary orbital angular momentum are denoted by  S  ⋆ and  L  b, respectively. The disk and planet’s angular momenta are assumed to be strongly coupled and evolve as a single angular momentum vector,  L . The mutual inclinations of the three vectors  S  ⋆,  L , and  L  b are described by the three angles θ sb, θ lb, and θ sl (the “0” subscript denotes the initial value of the angle). We assume θ sl,0 = 0. In panel (2), after the protoplanetary disk has dissipated, the spin of the star changes orientation, and the relative angles among the angular momenta are notated with an “i” subscript (for their intermediate values). Finally, in panel (3), after high-eccentricity migration has resulted in an HJ, the relative angles among the angular momenta are denoted with an “f” subscript. Note that while θ sb,f and θ sl,f are approximately constant in time, θ lb,f can still undergo large oscillations.
Paper: Linear and Circular Polarimetry of the Optically Bright Relativistic Tidal Disruption Event AT 2022cmc
Authors: Aleksandar Cikota, Giorgos Leloudas, Mattia Bulla, Lixin Dai, Justyn Maund, Igor Andreoni
Figure caption: Observing log of linear and circular polarimetry of AT 2022cmc. The green blocks on the top panels indicate the individual exposures, each of 350 s in the R band, and the corresponding HWP angles. The solid and dashed lines show the altitudes of the target and Moon, respectively. The bottom panels show the seeing measured by the Astronomical Site Monitoring (ASM) DIMM telescope at 500 nm (blue line) and the relative flux variation along the line of sight of the DIMM telescope (solid red line) during the observations. The dashed red lines indicate thresholds for the possible presence of clouds. Left: the linear polarimetry sequence of four HWP angles was repeated four times to increase the S/N. The individual sequences are indicated. Right: circular polarimetry was obtained at two orientations of the instrument, separated by 90°. At each orientation, four sequences of two quarter-wave plate positions were taken.