adsabs/AstroCLIMB huggingface dataset:
Paper: Small and Close-in Planets are Uncommon Around A-type Stars
Authors: Steven Giacalone, Courtney D. Dressing
Figure caption: Visualization of the sinusoid test described in Section 3.2. The black points show the phase-folded data of the event detected by the BLS periodogram. The solid light blue curves show the best-fit sinusoid models and the dashed dark blue curves show the best-fit transit models. The left-side panel shows the results for TIC 238597883 (TOI-1004), which strongly favors the transit model, and the right-side panel shows the results for TIC 1965523096, which strongly favors the sinusoid model. With our threshold of ΔBIC = 50, the former passes the sinusoid test and the latter fails.
Paper: Small and Close-in Planets are Uncommon Around A-type Stars
Authors: Steven Giacalone, Courtney D. Dressing
Figure caption: Coordinates and properties of the 20,257 A-type stars that are used in this study. In the top-most panel, each point is a star, with color indicating the number of sectors it has been observed by TESS.
Paper: Small and Close-in Planets are Uncommon Around A-type Stars
Authors: Steven Giacalone, Courtney D. Dressing
Figure caption: 2D histogram of the stars in our sample, binned according to their 1 hr CDPPs and their TESS magnitudes. Most stars in the sample have CDPPs between 0.1 and 1 parts per thousand.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: Left: SMA millimeter contours overplotted on the DECaPS z filter image of IRAS 08235–4316. Center: 12CO moment 8 map. Right: 12CO moment 1 map. SMA beams are shown in the bottom left of all panels. We overplot a dashed–dotted line that represents the optical dark lane, which can be seen to pass through the peaks of the SMA continuum and 12CO line data, and nearly perpendicular to the plausible velocity gradient in the moment 1 map. In these maps, north is up and east is left.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: 12CO channel maps, from 8.0 to 10.6 km s−1. The central component is highlighted by a black dashed–dotted ring. The spatially separated (at −3″ and 5″) northern extended component is highlighted by a red dash ring. These rings represent the same apertures from which we measure both 12CO flux spectra. The SMA beam is shown in the lower left of all panels. In these maps, north is up and east is left.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: Red, green, and blue (RGB) image of IRAS 08235–4316 (z, r, and g filters, respectively). A conical bright lobe and an adjacent fainter, parallel lobe are separated by a dark central lane, as expected for highly inclined embedded sources with outflows (see, e.g., J. Woitas et al. 2002; V. Delabrosse et al. 2024). The 8″ scale bar spans the approximate extent of the dark lane.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: 12CO spectra for apertures centered on the central source (top) and the northwest cloud (bottom). We shade in the four regions associated as being distinct CO components.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: νFν vs. wavelength, presenting all values from Table 1. We plot the individual and combined model spectra of three blackbody profiles (with temperatures of 1500 K in blue, 300 K in amber, and 30 K in green). Four (of 16) data points are not well described by the composite (marked in gray), whereas the other 12 data points are well described by the simple triple-blackbody distribution.
Paper: DECaPS and SMA Discovery of a Highly Inclined Class I Young Stellar Object with an Outflow: IRAS 08235–4316
Authors: Joshua Bennett Lovell, Kristina Monsch, Garrett K. Keating, David J. Wilner, Gordian Edenhofer, Mark Gurwell, Ramprasad Rao
Figure caption: Dust extinction as a function of distance along the LOS toward IRAS 08235–4316, based on the 3D dust extinction maps from G. Edenhofer et al. (2024). The data were extracted within a cone of radius 1° around IRAS 08235-4316's sky position. There are four strong peaks associated with this direction, located at 191 ± 7 pc, 462 ± 11 pc, 747 ± 14 pc, and 881 ± 19 pc (obtained by simple Gaussian fits).
Paper: Photometric and Spectroscopic Investigations of Three Large Amplitude Contact Binaries
Authors: Xin Xu, Kai Li, Fei Liu, Qian-Xue Yan, Yi-Fan Wang, Xin-Yu Cui, Jing-Yi Wang, Xing Gao, Guo-You Sun, Cheng-Yu Wu, Mu-Zi-Mei Li
Figure caption: The O − C diagrams of the three targets. For diagram of J034828, the black line represents a parabolic fit, and the red line represents a periodic sine function fit.
Paper: Photometric and Spectroscopic Investigations of Three Large Amplitude Contact Binaries
Authors: Xin Xu, Kai Li, Fei Liu, Qian-Xue Yan, Yi-Fan Wang, Xin-Yu Cui, Jing-Yi Wang, Xing Gao, Guo-You Sun, Cheng-Yu Wu, Mu-Zi-Mei Li
Figure caption: The relationships between mean residuals and mass ratio of the three targets.
Paper: Photometric and Spectroscopic Investigations of Three Large Amplitude Contact Binaries
Authors: Xin Xu, Kai Li, Fei Liu, Qian-Xue Yan, Yi-Fan Wang, Xin-Yu Cui, Jing-Yi Wang, Xing Gao, Guo-You Sun, Cheng-Yu Wu, Mu-Zi-Mei Li
Figure caption: The theoretical curves and observed curves of our observations and TESS.
Paper: Photometric and Spectroscopic Investigations of Three Large Amplitude Contact Binaries
Authors: Xin Xu, Kai Li, Fei Liu, Qian-Xue Yan, Yi-Fan Wang, Xin-Yu Cui, Jing-Yi Wang, Xing Gao, Guo-You Sun, Cheng-Yu Wu, Mu-Zi-Mei Li
Figure caption: The theoretical curves and observed curves of other observations.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: We perform leave-one-out cross-validation of our model, applying the selection function to 40 bootstrapped samples of the debiasing population. We avoid representing objects as themselves (which would guarantee perfect predictions) by using each object's second-nearest neighbor to predict its detection or nondetection. Overall, the model recreates the marginal distributions well. Deviations between the purple cross-validation region and the true discoveries reveal model bias and shortcomings. In particular, the model is fairly inaccurate in predicting discoveries as a function of M. Near the low boundary of a and e, the predictions are biased upwards, toward the bulk of the population. Other inconsistent regions include the peaks of m and a and the troughs of Ω.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: An unintuitive effect of a simple observational bias on the orbital distribution of discovered objects listed in the Minor Planet Center orbit database. Top panel: all Minor Planet Center objects by mean anomaly (M) as of 2024 February. Intuitively, we expect the intrinsic distribution of M in the solar system to be uniform. The peaks and troughs are much greater than the 5σ ranges of Poisson distributions around the mean, revealing a strong signal explained in the bottom panel. Bottom panel: the cause of M bias is revealed by spreading the data out by discovery date, with color representing the discovery density by mean anomaly within each year (rows have mean 1). At any given time, objects are discovered in a tight region around M = 0. As time passes, objects increase in M, and a year's set of discovered objects broadens as orbits with different orbital periods drift apart. Orbits of the main belt remain visible as diagonal lines for about two decades, until the drift eventually blurs them together into a uniform distribution with density 1.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: The structure of our SSO survey debiasing method. Using a debiasing population to query the survey's selection function, we can evaluate and reject arbitrarily many model solar systems with only a single survey simulation and discovery process.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: The selection function marginalized across each dimension. Dotted black lines show the fraction of debiasing objects discovered. Purple lines represent 40 bootstrapped samples of the debiasing population, shown to demonstrate an uncertainty region. Detection probability is strongly dependent on apparent magnitude (m), semimajor axis (a), and inclination (i), but only moderately dependent on other parameters, and nearly uniform with respect to longitude of perihelion (ϖ). Note how the discovery probability at high m converges to zero, but the convergence to a maximum at low m is not captured. The uncertainty region grows where we included few debiasing objects, such as at high e and low and high i.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: Discovered objects (black) scattered over a heat map of the selected literature population in each pair of {a, e, i, H}. Plots on the diagonal show the marginal cumulative distribution functions across each dimension. Visually, the populations appear to be in agreement, though the dearth of discovered objects around a ∼ 17, H ∼ 10.5, and of objects with both low a and low H are each noteworthy.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: Real objects discovered from a vs. e (top) and a vs. i (bottom). Resonances of Neptune are shown as vertical dashed lines, while curves of constant perihelion are dotted. Most discovered objects were TNOs rather than Centaurs, though this survey has the largest Centaur yield of any debiased survey to our knowledge.
Paper: A Well-Characterized Survey for Centaurs in Pan-STARRS1
Authors: Jacob A. Kurlander, Matthew J. Holman, Pedro H. Bernardinelli, Mario Jurić, Aren Heinze, Matthew J. Payne
Figure caption: A toy example showing realizations of two distinct distributions that share identical marginal distributions in two quantities of interest (“x” and “y”), but have distinct two-dimensional distributions. A one-dimensional test such as the KS test would fail to distinguish between these two populations, motivating a need for multivariate statistics.
Paper: The Stellar Disk Structure Revealed by the Mono-age Populations of the LAMOST Red Clump Star Sample
Authors: Zheng Yu, Bingqiu Chen, Jianhui Lian, Chun Wang, Xiaowei Liu
Figure caption: KS-band absolute magnitudes of primary RC stars as a function of metallicity [Fe/H]. Red points denote median values obtained by binning the data points into 15 bins with a bin size of 0.1 dex in [Fe/H]. The error bars indicate the standard deviations of the individual bins. The red dashed line is a third-order polynomial fit to the red points.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Upper panel: RV and O–C variation due to orbital motion with the third body. Lower panel: the components’ orbit and location at specific dates. Blue and red continuous lines show the orbits of Aab and B components, respectively, and CM represents the center of mass of the CN Lyn.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Upper panel: Hipparcos photometric data for CN Lyn. The left subfigure plots HP photometry (F. van Leeuwen et al. 1997) against Julian Date (JD). The right subfigure plots the same data phase folded using the ephemeris of J. M. Kreiner (2004). Lower panel: TESS photometric data for CN Lyn. The left subfigure plots flux against the Barycentric TESS Julian Date (BTJD). The right subfigure shows the same data folded using the ephemeris of J. M. Kreiner (2004).
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Observed RVs with best-fitting RV curves and photometric data with LC modeling. Filled and empty circles represent the RVs of the primary and secondary components of Aab, respectively. In the LC panel, red and blue dots represent the TESS and Hipparcos data, respectively, and the black curves are the best LC model for each photometric data set.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Disentangled component spectra is shown together with observed composite spectrum.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: A corner plot of the posteriors for the fundamental parameters of Aab components.
Paper: The Stellar Disk Structure Revealed by the Mono-age Populations of the LAMOST Red Clump Star Sample
Authors: Zheng Yu, Bingqiu Chen, Jianhui Lian, Chun Wang, Xiaowei Liu
Figure caption: Figures analogous to Figure 4 showing the fitting results of >9 Gyr mono-age populations.
Paper: The Stellar Disk Structure Revealed by the Mono-age Populations of the LAMOST Red Clump Star Sample
Authors: Zheng Yu, Bingqiu Chen, Jianhui Lian, Chun Wang, Xiaowei Liu
Figure caption: Figures analogous to Figure 4 showing the fitting results of 7–9 Gyr mono-age populations.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: The Galactic orbits and birth radii of CN Lyn in the Z × Rgc (a) and Rgc × t (b) diagrams. The filled yellow circles and triangles show the current and birth positions, respectively. The red arrow is the motion vector of CN Lyn today. The green and pink dotted lines show the orbit when errors in input parameters are considered, whereas the green and pink filled triangles represent the birth locations of the CN Lyn based on the lower and upper error estimates.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Upper panel: the distribution of chemical abundances of each component of CN Lyn versus atomic number. Red, yellow, and blue colors represent the primary, secondary, and tertiary components, respectively. Dashed lines represent the [Fe/H] value of each component. Lower panel: differences in chemical abundances ﹩\left({[X/H]}_{{\rm{Ab}}}-{[X/H]}_{{\rm{Aa}}}\right)﹩ in components of the A system according to atomic number.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Positions of the primary (Aa), the secondary (Ab), and the tertiary (B) components of CN Lyn on evolutionary tracks in (a) ﹩\mathrm{log}L\times {T}_{{\rm{eff}}}﹩, (b) R × Teff, and (c) ﹩\mathrm{log}\,g\times {T}_{\mathrm{eff}}﹩ planes, respectively. The different colored curves show the MESA evolutionary tracks of the derived metallicities (see Table 8) for the calculated masses. Red, blue, and brown colors represent the evolutionary track of each component: the primary, the secondary, and tertiary, respectively. The left turn in the blue tracks represents the Ab component starting to accrete mass from the Aa component.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Upper panel: each component's disentangled spectra with SP_Ace models. Lower parts in the panel show the residuals between the disentangled spectra and SP_Ace models. Lower panel: highlighted region from the disentangled spectra of the primary component with SP_Ace model shows each element used in chemical abundance calculations.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Element abundances for the four α elements with respect to Fe. Panels show CN Lyn's component stars and T. Bensby et al. (2014)’s stars in the thin disk, thick disk, and halo populations classified according to kinematic criteria.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: The result of the grid search. The best model is given by red plus in the figure with initial period and initial eccentricity, as 217 days and 0.9781, respectively. The color bar shows χ2 values.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Evolutionary tracks of the primary (Aa) and the secondary (Ab) components of CN Lyn in the ﹩\mathrm{log}L/{L}_{\odot }\times {T}_{{\rm{eff}}}﹩ plane.
Paper: Unveiling the Origins and Dynamics of the Hierarchical Triple Star System CN Lyn
Authors: Gökhan Yücel, Volkan Bakış, Remziye Canbay, Neslihan Alan, Timothy Banks, Selçuk Bilir
Figure caption: Change of orbital parameters (a), and radius of the components (b) of Aab components of CN Lyn with time.
Paper: Color–Magnitude Diagram of NGC 205 and Its RR Lyrae Variables
Authors: Ata Sarajedini
Figure caption: The metallicity distribution of ab-type RR Lyraes as determined using the A. Sarajedini et al. (2006) relation (upper panel) and the C. Alcock et al. (2000) relation (lower panel). The means and standard errors of the mean are given in each panel.
Paper: Color–Magnitude Diagram of NGC 205 and Its RR Lyrae Variables
Authors: Ata Sarajedini
Figure caption: The F606W luminosity function of NGC 205 in the region of the red clump after combining the data in the WFC1 and WFC2 chips. The red curves are Gaussian fits to the red clump at F606W) ≈ 25.3 and the AGB bump at F606W) ≈ 24.4.
Paper: Color–Magnitude Diagram of NGC 205 and Its RR Lyrae Variables
Authors: Ata Sarajedini
Figure caption: Period distributions for the RR Lyrae stars in NGC 205. The upper panel illustrates the RR Lyraes appearing in the WFC1 (246 RRL) chip, and the lower panel is for the stars in the WFC2 (233 RRLs) chip.
Paper: Color–Magnitude Diagram of NGC 205 and Its RR Lyrae Variables
Authors: Ata Sarajedini
Figure caption: Sample light curves for c-type RR Lyrae variables in NGC 205. Filled circles represent F814W magnitudes while the open circles are the F606W magnitudes.
Paper: PAH Feature Ratios around Stellar Clusters and Associations in 19 Nearby Galaxies
Authors: Daniel A. Dale, Gabrielle B. Graham, Ashley T. Barnes, Dalya Baron, Frank Bigiel, Médéric Boquien, Rupali Chandar, Jérémy Chastenet, Ryan Chown, Oleg V. Egorov, Simon C. O. Glover, Lindsey Hands, Kiana F. Henny, Remy Indebetouw, Ralf S. Klessen, Kirsten L. Larson, Janice C. Lee, Adam K. Leroy, Daniel Maschmann, Debosmita Pathak, M. Jimena Rodríguez, Erik Rosolowsky, Karin Sandstrom, Eva Schinnerer, Jessica Sutter, David A. Thilker, Tony D. Weinbeck, Bradley C. Whitmore, Thomas G. Williams, Aida Wofford
Figure caption: Top: continuum-subtracted flux ratios for stellar clusters in all 19 PHANGS–JWST Cycle 1 galaxies. The small data points are colored according to their ages as quantified in the color bar. The large open symbols indicate the median values for each age bin. Overlaid tracks are included for select subsets of the synthetic ratios extracted from the dust emission models of B. T. Draine et al. (2021), and the general trends for these tracks are indicated with the inset arrows/descriptions. The gray and black tracks are for small (a01 = 3 Å) and large (a01 = 5 Å) modeled PAH distributions, respectively, with both assuming logU = 0; ion = 0, 1, and 2; and age = 3, 10, 100, and 1000 Myr. Middle: using stellar associations instead of compact clusters. Bottom: individual diffuse regions along with the median values for clusters, associations, and diffuse regions.
Paper: PAH Feature Ratios around Stellar Clusters and Associations in 19 Nearby Galaxies
Authors: Daniel A. Dale, Gabrielle B. Graham, Ashley T. Barnes, Dalya Baron, Frank Bigiel, Médéric Boquien, Rupali Chandar, Jérémy Chastenet, Ryan Chown, Oleg V. Egorov, Simon C. O. Glover, Lindsey Hands, Kiana F. Henny, Remy Indebetouw, Ralf S. Klessen, Kirsten L. Larson, Janice C. Lee, Adam K. Leroy, Daniel Maschmann, Debosmita Pathak, M. Jimena Rodríguez, Erik Rosolowsky, Karin Sandstrom, Eva Schinnerer, Jessica Sutter, David A. Thilker, Tony D. Weinbeck, Bradley C. Whitmore, Thomas G. Williams, Aida Wofford
Figure caption: Average star formation rate surface densities (top) and spatially integrated offsets from the star-forming main sequence (bottom) as a function of median PAH feature ratios for each galaxy's clusters. Blue circles (red squares) use the F770W (F1130W) data. The best-fit trend lines are included along with the Spearman's rank correlation coefficients. The coefficients and the two-sided significance levels of their deviations from zero are (−0.33, 0.17), (−0.25, 0.29), (−0.50, 0.03), and (−0.45, 0.05).
Paper: PAH Feature Ratios around Stellar Clusters and Associations in 19 Nearby Galaxies
Authors: Daniel A. Dale, Gabrielle B. Graham, Ashley T. Barnes, Dalya Baron, Frank Bigiel, Médéric Boquien, Rupali Chandar, Jérémy Chastenet, Ryan Chown, Oleg V. Egorov, Simon C. O. Glover, Lindsey Hands, Kiana F. Henny, Remy Indebetouw, Ralf S. Klessen, Kirsten L. Larson, Janice C. Lee, Adam K. Leroy, Daniel Maschmann, Debosmita Pathak, M. Jimena Rodríguez, Erik Rosolowsky, Karin Sandstrom, Eva Schinnerer, Jessica Sutter, David A. Thilker, Tony D. Weinbeck, Bradley C. Whitmore, Thomas G. Williams, Aida Wofford
Figure caption: The F335MPAH/F1130W (top) and F770Wdust/F1130W (bottom) ratios as a function of radiation field hardness as measured by the [O III]/Hβ ratio corrected for extinction. The ratios for stellar clusters are shown as red circles and red histograms, and those for the diffuse regions are shown as blue squares and blue histograms. The dashed black line shows the linear fit to the combined clusters+diffuse regions. The lines for the histograms indicate the median values.