adsabs/AstroCLIMB huggingface dataset:
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: A combined figure for sulfur deficit d(S) on the vertical axis for the HSK12+ sample (top row) and VLT sample (bottom row) against (i) histograms of d(S) values with a bin size of 0.11 dex, (ii) 12+log(O/H), and (iii) absolute height above the Galactic plane “∣z∣” in kiloparsecs. The Galactic disk and bulge PN samples are color coded according to their basic age group from criteria outlined in Appendix C. Green indicates young and orange indicates old progenitor stars according to the adopted dating scheme. The black dashed line in the left panel outlines the overall distribution. The middle panel red vertical line indicates solar oxygen abundance.
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: Comparison of S/H vs. O/H for eight bulge PNs in common with Pottasch & Bernard-Salas (2015). The left panel shows S/H values from optical VLT observations in Paper III. The right panel gives S/H values inferred from PBS15 mid-infrared data. The dashed green line is the fit to the H2BCG data; the red asterisk denotes the solar abundance. For six out of eight PNe in common with the sample in PBS15 the mid-infrared S/H values  follow the expected trend line.
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: Differences between ﹩12+\mathrm{log}﹩(S/H) values from literature ICF formulae and our machine-learning (ML) approach. The HSK12+ sample in the left panel adopted the KW01 ICF scheme, while the right panel presents PNs from Paper III using the DMS14 ICF scheme. The left-skewed distribution in the HSK12+ panel suggests a contribution to the sulfur anomaly from the KW01 ICF scheme.
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: Fractional uncertainty in predicted icf(S) from the RF regressor as a function of log-scale true icf(S) for the test set. The contours illustrate the number density based on kernel density estimation. The black solid line denotes zero fractional uncertainty, with a high concentration of data points along this line indicating no systematic discrepancy between the predicted icf(S) from the RF regressor and the true values from the test set.
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: Fractional uncertainty in predicted Ar3+/Ar2+ (left) and Cl3+/Cl2+ (right) from the RF regressor as a function of log-scale true ionic fractions of the test set. The plots were constructed in the same manner as Figure B1.
Paper: Whither or Wither the Sulfur Anomaly in Planetary Nebulae?
Authors: Shuyu Tan, Quentin A. Parker
Figure caption: Comparison of Ne/H and Ar/H vs. O/H relationships using optical VLT observations and mid-infrared observations in PBS15, with symbols defined in Figure 3.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: NanoSIMS ion and isotope images of two X SiC grains from this study that had relatively low (M5-A5-G0071) and high (M5-A3-G0420) levels of Al contamination. The scale bar and contour line denotes 500 nm and the region of interest (ROI) for data reduction, respectively. The ROIs were chosen to maximally suppress N or Al contamination and/or topographic effects. The isotope ratio images were calculated using the same method as adopted for the isotope data reported in Table 1.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Panels (a)–(d) compare CCSN grain data from this study and Hoppe et al. (2023) with our CCSN nucleosynthesis calculations. The average composition of the Fe/Ni core was calculated by mixing Fe/Ni material from the v- and no-v-models with a mixing ratio of 3:2, respectively, and the calculated average compositions at explosion energies of (1–10) × 1051 erg are plotted as squares (increasing size with increasing E) with lines. In panel (a), the model calculations are out of scale (see discussion in Section 3.2.4). The effects of mixing with 28Si-rich Si/S material are illustrated using red arrows. In panel (e), shown is a schematic diagram of the “onion-shell” internal structure of a presupernova massive star.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Plots comparing BSE-EDX and NanoSIMS results for X SiC (panel (a)) and mainstream SiC (panel (b)) grains. The linear fits to the grain data are plotted as solid blue lines, and the corresponding slopes are given in each panel. Errors are all 1σ. The NanoSIMS data were calculated by adopting ΓMg/Si and ΓAl/Si values of 5.31 and 3.96, respectively. The linear fits were obtained using the CEREsFit.xlsm tool of Stephan & Trappitsch (2023). MSWD stands for mean squared weighted deviation, and R is the Pearson correlation coefficient.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: CASINO simulation (Drouin et al. 2007) of characteristic X-ray yields (C, Si, Al, and Mg K peaks) and electron trajectories for a 1 nA, 10 kV beam of 5 nm in size incident on an infinite slab of Si48C48AlMg3. In the inset, blue trajectories represent 1000 of the 10,000 calculated electron trajectories within the slab. The electron trajectory distribution spans a ∼0.8 μm diameter teardrop-shaped interaction volume, comparable in size to the average grain diameter in this study.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Comparison of the ν- and no-ν-models in deep CCSN regions at the lowest and highest considered explosion energies. In the Fe/Ni core, CCSN layers with relatively homogenous compositions are chosen for calculating the average compositions (highlighted in yellow) that are shown as magenta squares in Figures 3 and A8.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Plots comparing BSE-EDX and NanoSIMS analysis results of all X grains from this study. In panel (a), the linear fit to the grain data is plotted as a solid red line and was obtained by using the CEREsFit.xlsm tool of Stephan & Trappitsch (2023). In panel (b), given the small R value, we did not obtain any linear fit to the grain data and instead plotted the linear fit to the selected MS grain data in Figure 2(b) for comparison. Data for Si3N4 grains are plotted for comparison. Errors are all 1σ.
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: Meridional slices, i.e., xz-plane with z being the vertical axis, of the density ρ, the Lorentz factor at infinity Γ, the velocity component aligned with the rotation axis v  z , and the electron fraction Y  e . We only plot the Y  e  for the unbound material. We show snapshots at t − t map = 10.1 ms, where t map = 17 ms after coalescence of the NS binary. The top row shows the evolution of the remnant using an M1 scheme while the bottom row shows a similar evolution using a leakage scheme. The dashed lines are isodensity contours of ρ = 107, 108, 109, and 1011 g cm−3.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: The plot in panel (a) is the same as Figure A2(b) but for 126 MS grains. In panel (b), MS grains from panel (a) are compared to X grains in Figure A2 for their grain size distributions.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Same as Figure 3 except that the ν-model calculations for the Fe/Ni core are shown for comparisons .
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: Histograms of the radial velocity v  r  of the unbound material (top panels), where r is the radius in spherical coordinates, and the Y  e  of the unbound material (bottom panels), shown at different times during the dynamical simulation (4.2, 8.5, and 12.7ms), for the leakage and M1 simulations. Each column corresponds to a different time in the evolution.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: EDX- and NanoSIMS-derived initial 26Al/27Al ratios of X grains from this study and Hoppe et al. (2023). Labeled is grain M5-A3-0420 that had significant Al contamination (Figure 1). In the insert, the SEM image of grain M5-A7-1003 shows that this X grain was part of a SiC aggregate so that the adjacent SiC, which is an MS grain with 26Al/27Al = 0.001, significantly lowered its EDX-derived Mg content and, in turn, 26Al/27Al ratio. The scale bar denotes 500 nm.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Plots comparing the isotopic compositions of the three subtypes of X grains that were initially proposed by Lin et al. (2010) and later modified by Stephan et al. (2021). Si3N4 grain data are also plotted for comparison.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: NanoSIMS Images of Burma spinel grains. The scale bar denotes 1 μm.
Paper: Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains
Authors: Nan Liu, Conel M. O'D. Alexander, Bradley S. Meyer, Larry R. Nittler, Jianhua Wang, Rhonda M. Stroud
Figure caption: Initial 26Al/27Al ratios of X and Si3N4 grains from this study as a function of grain size.
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: AB magnitudes in ugrizJHK  s  bands. Top two rows: band light curves for the total ejecta and the polar ejecta. From left to right, the band light curves correspond to the ejecta produced during the course of the simulation, and those produced assuming a total remnant NS lifetime of ∼240 ms and ∼1 s, respectively. The black dotted line gives the effective temperature computed at the photosphere. Bottom row: comparison with broadband data for AT2017gfo, for the case where we obtain ∼0.02M ⊙ of ejecta. The aggregated broadband data were collected by multiple teams and compiled in Villar et al. (2017).
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: Input profiles for SNEC showing averaged quantities for the NS remnant outflow as a function of mass coordinate. The top two panels show the radial velocity (solid blue line) and temperature (dashed black line) of the total ejecta on the left, and the corresponding Y  e  (solid blue line) and opacity (dashed black line) on the right. The bottom two panels show the same quantities plotted for the polar ejecta.
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: Mass-weighted abundance as a function of mass number for the NS remnant outflow. The different colors correspond to different constant neutrino luminosities employed during postprocessing. The solar abundance pattern has been scaled to match the second r-process peak at A ∼ 130 for the zero luminosity setting. The dashed lines show the total abundance pattern produced in combination with the dynamical ejecta from Radice et al. (2018).
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: The evolution of density (black lines) and temperature (blue lines) for two sample tracers. The solid lines show the original tracer particle data, while the dashed lines show the data extrapolated by SkyNet under the assumption of homologous expansion. This evolution corresponds to the case where zero neutrino luminosity is employed during postprocessing.
Paper: Magnetized Outflows from Short-lived Neutron Star Merger Remnants Can Produce a Blue Kilonova
Authors: Sanjana Curtis, Pablo Bosch, Philipp Mösta, David Radice, Sebastiano Bernuzzi, Albino Perego, Roland Haas, Erik Schnetter
Figure caption: Meridional slices, i.e., xz-plane with z being the vertical axis, showing the time evolution of the Y  e  for the unbound material. We show six snapshots at t − t map  =  1.02, 2.04, 4.08, 8.05, 10.1, and 11.91 ms, where t map  =  17 ms after coalescence of the NS binary.
Paper: Constraints on Cosmological Coupling from the Accretion History of Supermassive Black Holes
Authors: Mark Lacy, Athena Engholm, Duncan Farrah, Kiana Ejercito
Figure caption: Middle and right panels: constraints on the value of the cosmological coupling strength k (Equation (1)) based on comparing the growth of SMBH density via accretion to the local density of SMBHs. Middle: assuming η = 0.1 (which agrees well with the GD07 estimate of ρ •(0) if k = 0); and right: η = 0.3, the maximum theoretical value for a maximally spinning BH (Thorne 1974). In both, the red triangle and error bar represents our estimate of the local SMBH mass density from the M •–M bulge relation and the blue square and error bar (which extends well above the plotted range) the preliminary estimate from the GWB, as discussed in Section 3.2. Also in both, the black lines represent the minimum mass density in SMBHs needed to account for the observed luminosity function for different mean values of λ and the cyan-solid, magenta-dotted, and red-dashed lines the growth in BH mass density for different values of k assuming the AGN luminosity function of Shen et al. (2020). The shaded region around the k = 0 (cyan-solid) line corresponds to the uncertainty in Shen et al. (2020; uncertainty ranges for other values of k are similar). Far left a compilation of estimates of the local mass density in black holes from the literature: S04: Shankar et al. (2004), M04: Marconi et al. (2004), H07: Hopkins et al. (2007), G07: Graham et al. (2007), GD07: Graham & Driver (2007), YL08: Yu & Lu (2008), S09: Shankar et al. (2009), with the cyan shaded area indicating the range of uncertainty at z = 0 for the Shen et al. (2020) luminosity function, assuming η = 0.1.
Paper: Three-dimensional Velocity Fields of the Solar Filament Eruptions Detected by CHASE
Authors: Ye Qiu, Chuan Li, Yang Guo, Zhen Li, Mingde Ding, Linggao Kong
Figure caption: Spectral profiles and cloud-model fitting results of the prominence (a)–(c) and filament (d)–(f). The dashed curve is the averaged profile of the background region, with the dashed vertical line marking its line center. The plus symbols represent the observed profiles, while the colored curves exhibit the cloud model fitting results with the corresponding χ 2 values given at lower left. The cyan curve in panel (f) is the single-cloud fitting result, and the orange is double-cloud.
Paper: Three-dimensional Velocity Fields of the Solar Filament Eruptions Detected by CHASE
Authors: Ye Qiu, Chuan Li, Yang Guo, Zhen Li, Mingde Ding, Linggao Kong
Figure caption: Overview of the eruptive prominence on 2022 August 17. (a)–(c): SDO/AIA 131 Å images. (d)–(f): CHASE Hα line-center images. The white rectangle marks the background region for zero Doppler shift. (g)–(i): enhanced images corresponding to (d)–(f), which are weight averaged along the wavelength dimension with a Gaussian function.
Paper: Three-dimensional Velocity Fields of the Solar Filament Eruptions Detected by CHASE
Authors: Ye Qiu, Chuan Li, Yang Guo, Zhen Li, Mingde Ding, Linggao Kong
Figure caption: Overview of the eruptive filament on 2023 May 8. (a)–(c): SDO/AIA 94 Å images. (d)–(f): CHASE Ha line-center images. The black and green contours mark the −300 G and 300 G LOS photospheric magnetic fields. The white rectangle in panel (d) marks the quiescent region chosen as the zero-shifted background. (g)–(i): enhanced images corresponding to (d)–(f). The white contours outline the recognized filament region.
Paper: Spectacular Nucleosynthesis from Early Massive Stars
Authors: Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, José Sánchez-Gallego
Figure caption: Initial mass vs. maximum [Fe/H], [C/O], [Na/Mg], [Mg/Fe], and [Zn/Fe] for zero-metallicity supernovae from five yield grids: CCSNe from HW10 (fiducial mixing, E  =  0.3–2.4 B in steps of 2×), HNe from G18 (no mixing, E  =  5,  10,  50,  100 B), PISNe from HW02, all types of supernovae from NKT13, and CCSNe from E20. Point sizes are proportional to log explosion energy (0.3–100 B). The horizontal red lines and shaded regions show the abundance of J0931 + 0038. First row: maximum [Fe/H] strongly prefers higher-mass progenitor stars with M  >  50 M ⊙. Larger explosion energies tend to synthesize more Fe but dilute into more H, with the balance indicated by vertical trends in point sizes. Second row: [C/O] rules out low-mass CCSNe (M  ≲  20 M ⊙). Third and fourth rows: [Na/Mg] and [Mg/Fe] disfavor intermediate-mass CCSNe (20–80 M ⊙). Higher-energy HNe match the abundances better and allow progenitors down to 40 M ⊙, but these all strongly violate the [Fe/H] constraint. E20 is removed from the [Na/Mg] plot, as the Na yields are not predicted. Fifth row: PISNe (M  >  140 M ⊙) are unable to produce significant Zn. Sixth row: estimated stellar fate given initial mass for a single, metal-poor, nonrotating star (HW02).
Paper: Spectacular Nucleosynthesis from Early Massive Stars
Authors: Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, José Sánchez-Gallego
Figure caption: Representative best-matching nucleosynthesis models. Abundances of J0931 + 0038 are given as red squares with error bars. In the top panel, the large open blue circles connected by solid lines indicate the best-fit HN model (G18) The dotted blue line with small points and dashed blue line with small open circles indicate adding the HNe to a high-entropy proton-rich wind pattern (Bliss et al. 2018) and weak r-process pattern (Holmbeck et al. 2023), respectively. In the bottom panel, the filled purple circles with solid lines indicate the best-fit PISN model (HW02). The dotted purple line with small open circles indicates the same model with a modified i-process (calculated using the framework in Roederer et al. 2022; see Appendix B for details). The HN is the best fit to the lighter elements and has leeway to fit the heavier elements, but the high energy underpredicts [Fe/H]. The PISN easily matches the high [Fe/H], and we speculate that a full calculation of a metal-enriched PISN progenitor and explosion with i-process could remedy the disadvantages seen here.
Paper: Spectacular Nucleosynthesis from Early Massive Stars
Authors: Alexander P. Ji, Sanjana Curtis, Nicholas Storm, Vedant Chandra, Kevin C. Schlaufman, Keivan G. Stassun, Alexander Heger, Marco Pignatari, Adrian M. Price-Whelan, Maria Bergemann, Guy S. Stringfellow, Carla Fröhlich, Henrique Reggiani, Erika M. Holmbeck, Jamie Tayar, Shivani P. Shah, Emily J. Griffith, Chervin F. P. Laporte, Andrew R. Casey, Keith Hawkins, Danny Horta, William Cerny, Pierre Thibodeaux, Sam A. Usman, João A. S. Amarante, Rachael L. Beaton, Phillip A. Cargile, Cristina Chiappini, Charlie Conroy, Jennifer A. Johnson, Juna A. Kollmeier, Haining Li, Sarah Loebman, Georges Meynet, Dmitry Bizyaev, Joel R. Brownstein, Pramod Gupta, Sean Morrison, Kaike Pan, Solange V. Ramirez, Hans-Walter Rix, José Sánchez-Gallego
Figure caption: Composition of J0931+0038 (red square) for Na, Ba, Mg, and Sr compared to the SAGA database (gray points), higher-mass classical dwarf galaxies (blue squares), and lower-mass ultra-faint dwarf galaxies (yellow diamonds). The dashed black line is an outlier-clipped third-order polynomial fit to the SAGA data. The horizontal red line is the [X/H] of J0931+0038. In the top two panels, the red shaded region indicates [Fe/H] < −3, the ISM metallicity range that alone would contribute all of the Na, Ba, and other underabundant elements like N, K, and Sc observed in J0931+0038. The bottom two panels, Mg and Sr, show that explaining the low N, Na, K, Sc, and Ba by simply adding Fe (e.g., with a Type Ia supernova) would require extremely high abundances of other elements.