adsabs/AstroCLIMB huggingface dataset:
Paper: Fan-beamed X-Ray Emission from 1 to above 130 keV from the Ultraluminous X-Ray Pulsar RX J0209.6-7427 in the Small Magellanic Cloud
Authors: X. Hou, M. Y. Ge, L. Ji, S. N. Zhang, Y. You, L. Tao, S. Zhang, R. Soria, H. Feng, M. Zhou, Y. L. Tuo, L. M. Song, J. C. Wang
Figure caption: Left: the pulse profile evolution of RX 0209.6−7427 with time using NICER data. Right: representative pulse profiles at different epochs using NICER data.
Paper: Fan-beamed X-Ray Emission from 1 to above 130 keV from the Ultraluminous X-Ray Pulsar RX J0209.6-7427 in the Small Magellanic Cloud
Authors: X. Hou, M. Y. Ge, L. Ji, S. N. Zhang, Y. You, L. Tao, S. Zhang, R. Soria, H. Feng, M. Zhou, Y. L. Tuo, L. M. Song, J. C. Wang
Figure caption: The spin frequency derivative ﹩\dot{\nu }﹩ as function of time using NICER data. The ﹩\dot{\nu }﹩ values are shown as blue squares. The green solid line is the smoothed line of ﹩\dot{\nu }﹩, and the red solid line is the bolometric luminosity of the source. The horizontal dashed line represents ﹩\dot{\nu }=0﹩. All the error bars are given at the 68% confidence level.
Paper: Fan-beamed X-Ray Emission from 1 to above 130 keV from the Ultraluminous X-Ray Pulsar RX J0209.6-7427 in the Small Magellanic Cloud
Authors: X. Hou, M. Y. Ge, L. Ji, S. N. Zhang, Y. You, L. Tao, S. Zhang, R. Soria, H. Feng, M. Zhou, Y. L. Tuo, L. M. Song, J. C. Wang
Figure caption: Upper panel: the luminosity vs. the frequency derivative. The red line is the fit using the GL torque model, and blue dots with 1σ error bars are from the NICER data. Lower panel: the residuals to the best-fit model.
Paper: Kilonova and Optical Afterglow from Binary Neutron Star Mergers. I. Luminosity Function and Color Evolution
Authors: Jin-Ping Zhu, Yuan-Pei Yang, Bing Zhang, He Gao, Yun-Wei Yu
Figure caption: The griJ-band fading rates of AT2017gfo (red lines), AT2018cow (green lines), AT2018kzr (blue lines), ATLAS19dqr (orange lines), SN2004eo (SN Ia; black lines), and the total emission of our modeled GW170817-like kilonova and afterglow along different lines of sight (dash-dotted lines).
Paper: Kilonova and Optical Afterglow from Binary Neutron Star Mergers. I. Luminosity Function and Color Evolution
Authors: Jin-Ping Zhu, Yuan-Pei Yang, Bing Zhang, He Gao, Yun-Wei Yu
Figure caption: Color evolution of AT2017gfo (red circles), AT2018cow (green squares), AT2018kzr (orange hexagons), ATLAS19dqr (blue diamonds), PS1-12bb (yellow stars; Drout et al. 2014), and SN2004eo (supernova Ia, black pentagons), in g − r, g − i, g − J, r − i, r − J, and i − J color–time phase spaces. Different color lines represent the color evolution of the GW170817-like kilonova modeling with different viewing angle ﹩\sin {\theta }_{{\rm{v}}}﹩. The corresponding values of ﹩\sin {\theta }_{{\rm{v}}}﹩ for different color lines are shown in the color bar.
Paper: Kilonova and Optical Afterglow from Binary Neutron Star Mergers. I. Luminosity Function and Color Evolution
Authors: Jin-Ping Zhu, Yuan-Pei Yang, Bing Zhang, He Gao, Yun-Wei Yu
Figure caption: Panels from left to right represent the PDFs of the absolute magnitude, the PDFs of the apparent magnitude, and the cumulative distributions of the apparent magnitude for kilonova and afterglow emissions in the griJ bands, respectively. Here, the bin width of the histograms is set to Δ = 0.4 mag.
Paper: Kilonova and Optical Afterglow from Binary Neutron Star Mergers. I. Luminosity Function and Color Evolution
Authors: Jin-Ping Zhu, Yuan-Pei Yang, Bing Zhang, He Gao, Yun-Wei Yu
Figure caption: Color evolution patterns of our modeled GW170817-like kilonova (left subpanels) and total emission of GW170817-like kilonova plus afterglow (right subpanels) in g − r, g − i, g − J, r − i, r − J, and i − J color–time spaces. The dash-dotted gray lines represent the color evolution of the afterglow. The corresponding values of ﹩\sin {\theta }_{{\rm{v}}}﹩ for different color lines are shown in the label of each panel.
Paper: Kilonova and Optical Afterglow from Binary Neutron Star Mergers. I. Luminosity Function and Color Evolution
Authors: Jin-Ping Zhu, Yuan-Pei Yang, Bing Zhang, He Gao, Yun-Wei Yu
Figure caption: Similar to Figure 3, but for the r-band afterglow light curves considering several different viewing angles, including ﹩\sin {\theta }_{{\rm{v}}}=0,0.05,0.1,0.2,0.3,\mathrm{and}\,0.4﹩.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: 1D line power spectra of the hydrodynamical skewers of the different simulations (solid lines) compared to the power spectra for the FGPA-based skewers (dashed lines) and the FGPA-based skewers with best-fit slope values (dotted lines). The stars denote the observed power spectrum at z = 2.2 from Chabanier et al. (2019), which have been down-scaled by a factor of 1.7 to match the amplitude of the Nyx power spectrum at z = 2.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: PDFs of the Lyα transmission. For each simulation we compare the distribution of the hydrodynamical skewers (solid lines) to that of the FGPA-based skewers (dashed lines) and the FGPA-based skewers with best-fit slope values (dotted lines). The observed data points from Kim et al. (2007) are also shown for reference (stars).
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Lyα transmission–DM density distribution for EAGLE compared to the FGPA-based distribution as well as the grid with varying FGPA β slopes. The contours show the 2% level of the PDF of the distribution.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Properties of a single skewer through the center of the EAGLE simulation. The top panel shows the Lyα transmission of the hydrodynamical skewer, as well as the same sightline from the FGPA skewers. The second panel displays the density along the sightline. The third panel shows the velocity along the skewer. The final panel gives the gas temperature along the skewer.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Lyα transmission–DM density distribution for Nyx compared to the FGPA-based distribution as well as the grid with varying FGPA β slopes. The contours show the 2% level of the PDF of the distribution.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Properties of a single skewer through the center of the Illustris-1 simulation. The top panel shows the Lyα transmission of the hydrodynamical skewer, as well as the same sightline from the FGPA skewers. The second panel displays the density along the sightline. The third panel shows the velocity along the skewer. The final panel gives the gas temperature along the skewer.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Properties of a single skewer through the center of the TNG100-1 simulation. The top panel shows the Lyα transmission of the hydrodynamical skewer, as well as the same sightline from the FGPA skewers. The second panel displays the density along the sightline. The third panel shows the velocity along the skewer. The final panel gives the gas temperature along the skewer.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Lyα transmission–DM density distribution for Illustris-1 compared to the FGPA-based distribution as well as the grid with varying FGPA β slopes. The contours show the 2% level of the PDF of the distribution.
Paper: Constraining the Fluctuating Gunn–Peterson Approximation using Lyα Forest Tomography at z = 2
Authors: Robin Kooistra, Khee-Gan Lee, Benjamin Horowitz
Figure caption: Lyα transmission–DM density distribution for TNG100-1 compared to the FGPA-based distribution as well as the grid with varying FGPA β slopes. The contours show the 2% level of the PDF of the distribution.
Paper: Comparison of Exact and Approximate MHD Slow Body Mode Solutions in Photospheric Waveguides
Authors: Anwar A. Aldhafeeri, Gary Verth, Viktor Fedun, Matthew Lennard, I. Ballai
Figure caption: Dispersion curves for slow body kink (panel (a)) and sausage (panel (b)) modes in a photospheric flux tube. The solid lines correspond to the variation of the phase speed of waves in units of the internal sound speed obtained based on the dispersion relation (Equation (5)), while the dashed lines correspond to the solutions of v  zi  = 0 on the boundary of the cylindrical waveguide, where the expression of v  zi  is given by Equation (11). The different colors denote different wave harmonics; red stands for the fundamental modes, while blue, magenta, and green lines denote subsequent higher harmonics. Panels (c) and (d) show the percentage error in finding the solutions of the dispersion relation (Equation (5)) and the solutions obtained by assuming v  zi  = 0. The colors of the curves correspond to the wave harmonics of the sausage and kink modes shown in panels (a) and (b).
Paper: Comparison of Exact and Approximate MHD Slow Body Mode Solutions in Photospheric Waveguides
Authors: Anwar A. Aldhafeeri, Gary Verth, Viktor Fedun, Matthew Lennard, I. Ballai
Figure caption: Variation of the z-component of the velocity across the boundary of a cylindrical waveguide for slow sausage body modes under photospheric conditions. This eigenfunction is plotted for an  i  < 4 (panels (a)–(c)) and ≥4 (panels (d)–(f)). Panels (a) and (d) show the dependence of the amplitude of v  z  on the radial distance in units of the waveguide’s radius inside (blue) and outside (magenta) the tube. The maximum amplitudes of v  z  inside the flux tube (normalized by the largest value) and at the boundary are shown in panels (b) and (d). The blue dots indicate the maximum amplitude of v  z  inside the flux tube for various modes, while the green dots show the maximum amplitude at the tube boundary. Panels (c) and (f) show the absolute value of the ratio of the maximum amplitude of v  z  at the boundary of the waveguide and the maximum value attained inside the waveguide. On the horizontal axis of panels (b), (c), (e), and (f), we denote the modes that correspond to different values of the radial wavenumber.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The spectra in the top and middle panels were extracted from the time intervals marked in the blue and orange intervals, respectively, in the light curve in the lower right part of the bottom panel. The upper left part of this bottom panel shows the comparison between the soft spectra in the blue and orange intervals, while the lower left part shows the variation in time with the color map shown in the upper right part. The red solid lines are the models in the first column of Table 2 for the first interval, and the model in the third column of Table 2 for the second interval.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The averaged MOS-1 spectrum over the whole XMM-Newton exposure, on a logarithmic scale, and in red a model with three thermal components like the one in Table 3. The iron feature at ≃6.7  keV is detected with low count rate, but it is clearly present during the whole exposure time, and indicates the presence of the hottest component, even if its flux has decreased since day 18.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The spectra of the first interval in the 20–30 Å range, and the fit with the model in Table 3 (red solid lines). The third component at lower temperature is necessary for the fit in this range, but it was not evident in the higher HETG energy range three days earlier.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The RGS spectrum measured on 2006 March 10, 26 days after the optical maximum, is plotted in black and compared in the 20–30 Å range with the RGS spectrum observed on 2021 August 30, 21 days after the optical maximum, plotted in red.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The O VIII H-like line observed with the RGS, shown in velocity space with 0 at rest wavelength of 18.9761 Å, and the fit with a Gaussian. The asymmetry, which we attribute to differential absorption in the receding outflow and in the one toward us, is more evident for lines with low ionization potential.
Paper: Shocks in the Outflow of the RS Oph 2021 Eruption Observed with X-Ray Gratings
Authors: Marina Orio, E. Behar, G. J. M. Luna, J. J. Drake, J. Gallagher, J. S. Nichols, J. U. Ness, A. Dobrotka, J. Mikolajewska, M. Della Valle, R. Ignace, R. Rahin
Figure caption: The 0.15–10 keV light curve measured with EPIC pn, binned with bins of 1000 s.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: Top panel: a schematic picture of a GRB LC in the rest frame with the main features. Bottom panel: a plot where the properties of the SN LC in the case of association with a GRB are highlighted: we remind that the template LC is the one of SN 1998bw (colored in blue in the panel), while the examples of properties refer to SN 2003lw.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: (a) The correlation between ﹩{\mathrm{log}}_{10}{L}_{a,\mathrm{opt}}﹩ and ﹩{\mathrm{log}}_{10}{t}_{p}^{* }﹩ before the EP correction. (b) The correlation between ﹩{\mathrm{log}}_{10}L{{\prime} }_{a,\mathrm{opt}}﹩ and ﹩{\mathrm{log}}_{10}{t}_{p}^{* ^{\prime} }﹩ after correcting both the variables with the EP method. The color-coding is the following: red refers to the AB subsample and green to the remaining E-graded event (GRB 111228A). For the fitting lines, orange indicates the full sample fitting and magenta the AB subsample fitting. The lines correspond to the fitting with ODR method parameters.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: (a) The limiting curve applied to the variable ﹩{t}_{p}^{* ^{\prime} }﹩ expressed as the log10 of its values in s. (b) The plot τ-k for this variable: it can be seen that the ﹩{k}_{{t}_{p}^{* ^{\prime} }}﹩ value is obtained at the level τ = 0.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: The flowchart here presented summarizes the steps of the current research for probable correlations in the sample of GRB-SN associations.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: The scatter matrix for the variables not corrected with EP, removing only the two shock breakout events (GRB 060218/SN 2006aj and GRB 080109/SN 2008D). For brevity, we here write log in place of log10.
Paper: The Quest for New Correlations in the Realm of the Gamma-Ray Burst—Supernova Connection
Authors: M. G. Dainotti, B. De Simone, K. M. Islam, K. Kawaguchi, T. J. Moriya, T. Takiwaki, N. Tominaga, A. Gangopadhyay
Figure caption: The scatter matrix with the EP-corrected variables, removing only the two shock breakout events (GRB 060218/SN 2006aj and GRB 080109/SN 2008D). For brevity, we here write log in place of log10.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: Line ratio diagrams for five emission lines spanning the different ionization zones with the observed line ratio plotted as the point for J104457 and J141851. The “Stars Only” column shows the CLOUDY photoionization models where we used the ionizing continuum from the stellar population we fit to these galaxies in Section 3.2 as the input ionizing spectrum. Each line is a different metallicity from low metallicity at 1% Z ⊙ in yellow to 11% Z ⊙ in purple for J104457, and for J141851 the range starts with 3% Z ⊙ in yellow and goes to 13% Z ⊙ in purple. The black dashed line shows the results of a model run with the observed gas-phase metallicity of each galaxy, 5.8% Z ⊙ for J104457 and 8.7% Z ⊙ for J141851. In the “Stars + BB” column, the models are plotted in bands with the same metallicity color-coding system, but the bands now include the effects of the blackbodies we modeled. The band is bordered by a dotted line showing the 0% L tot (no BB) model and a dashed–dotted line showing the 65% L tot from a 100 kK blackbody. The black hatched region shows the models run with the observed gas-phase metallicity of the galaxy.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption:  CLOUDY photoionization models of several nebular emission line ratios resulting from BPASS single-age stellar populations. The models are color-coded by their metallicity and are plotted as shaded bands to represent the range of ages, with the lower edge at 1 Myr and the upper edge at 3 Myr. For comparison, we plot the observed line ratios from J104457 (circular point), J141851 (square point), and the Berg et al. (2019b) sample (triangular point). The points are color-coded according to the measured nebular metallicity of each galaxy, along the same color scale as the models. The line ratios plotted are separated by their ionization potential energies such that low-ionization species are in the top row, and high-ionization species are in the bottom row, demonstrating the progressive discrepancy between models and observations with higher ionization potential.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: Optical LBT/MODS spectrum of J104457 (top) and J141851 (bottom), highlighting the blue and Wolf–Rayet bump regions (blue and purple inset windows, respectively). In the blue inset window, there are strong emission lines, but they appear narrow and nebular in origin, whereas there is a lack of any features in the purple inset window for J141851 but a possible C IV bump in J104457, which we discuss in Section 5.3.(The data used to create this figure are available.)
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: The UV BPT diagram plotted with C IV λλ1548,50/He II λ1640 vs. O III] λ1666/He II λ1640. The teal and purple shaded boxes highlight the regions typical of photoionization models for star formation only and AGN only, respectively. In comparison, we plot the models for J104457, where the rightmost line maps the models produced by the stellar population fits for a range of ionization parameters, extending from logU = −1 at the top to logU = −3.5 at the bottom with horizontal lines marking steps of 0.5 in logU. Models adding contributions from an 80 kK blackbody are plotted as narrow lines, where each subsequent model to the left increases the contribution from the blackbody by 20%. The arrow indicates the direction the models should move to account for the discrepancy between abundances calculated from ICFs using continuous and burst star formation models.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: Combined stellar population and BB models for J104457 and J141851 to show the effects of BB temperature and percentage. Each temperature is plotted as a different color band with 60 kK as orange, 80 kK as pink, and 100 kK as blue. The bands range from the lower dotted line as a BB with 0% L tot to the upper dashed–dotted line showing 75% L tot and include all metallicity steps from the models. The pink dashed lines show the 10% L tot steps from 5% to 75% for an 80 kK blackbody run with the observed gas-phase metallicity for each galaxy. The point is the observed line ratio for the galaxy.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: The HST/COS NUV acquisition images of J104457 (top) and J141851 (bottom) are shown in the left column. The 2.″5 COS aperture used for the UV spectra is shown as a gold circle. The spectrograph position angle is noted in the corner and is used to determine the spatial and spectral axes. In comparison, the 1″ LBT/MODS slit (black lines) captures most of the NUV light, but may miss a significant fraction of the extended nebular emission. In the right column, we plot the spatial and spectral light profiles captured within the COS aperture. The 0.″6 instrumental profile of COS is shown in gold.
Paper: Characterizing Extreme Emission Line Galaxies. II. A Self-consistent Model of Their Ionizing Spectrum 
Authors: Grace M. Olivier, Danielle A. Berg, John Chisholm, Dawn K. Erb, Richard W. Pogge, Evan D. Skillman
Figure caption: The UV spectra of J104457 and J141851 and the best-fit continuum models. The data are plotted in black, and the spectra are normalized by their flux at 1495 Å. We show the continuum fits from the Starburst 99 models (Leitherer et al. 1999) in orange and BPASS models (Eldridge et al. 2017) in pink for J104457 in the top panel and J141851 in the bottom panel. We also plot the residuals, continuum fit subtracted from the data, in the bottom plot of each panel. The zoomed-in regions highlight detections of absorption lines from highly ionized metal absorption features—Fe V and S V—that are only present in the photospheres of the most-massive and hottest stars.