METAL: The Metal Evolution, Transport, and Abundance in the Large Magellanic Cloud Hubble program. IV. Calibration of Dust Depletions vs Abundance Ratios in the Milky Way and Magellanic Clouds and Application to Damped Lyman-alpha Systems

37 pages; 22 figuresThe evolution of the metal content of the universe can be tracked through rest-frame UV spectroscopy of damped Ly-$\alpha$ systems (DLAs). Gas-phase abundances in DLAs must be corrected for dust depletion effects, which can be accomplished by calibrating the relation between abundance ratios such as [Zn/Fe] and depletions (the fraction of metals in gas, as opposed to dust). Using samples of gas-phase abundances and depletions in the Milky Way (MW), LMC, and SMC, we demonstrate that the relation between [Zn/Fe] and other abundance ratios does not change significantly between these local galaxies and DLAs, indicating that [Zn/Fe] should trace depletions of heavy elements in those systems. The availability of photospheric abundances in young massive stars, a proxy for the total (gas+dust) metallicity of neutral gas, in the MW LMC, and SMC allows us to calibrate the relation between [Zn/Fe] and depletions in these nearby galaxies. We apply the local calibrations of depletions to DLA systems. We find that the fraction of metals in dust, the dust-to-gas-ratio, and total abundances are 2-5 times lower than inferred from previous depletion calibrations based on MW measurements and a different formalism. However, the trend of dust abundance vs. metallicity remains only slightly sub-linear for all existing depletion calibrations, contrary to what is inferred from FIR, 21 cm, and CO emission in nearby galaxies and predicted by chemical evolution models. Observational constraints on the FIR dust opacity and depletions at metallicities lower than 20\% solar will be needed to resolve this tension

The Panchromatic Hubble Andromeda Treasury. XXI. The Legacy Resolved Stellar Photometry Catalog

We present the final legacy version of stellar photometry for the Panchromatic Hubble Andromeda Treasury (PHAT) survey. We have reprocessed all of the Hubble Space Telescope Wide Field Camera 3 and Advanced Camera for Surveys near-ultraviolet (F275W, F336W), optical (F475W, F814W), and near-infrared (F110W, F160W) imaging from the PHAT survey using an improved method that optimized the survey depth and chip-gap coverage by including all overlapping exposures in all bands in the photometry. An additional improvement was gained through the use of charge transfer efficiency (CTE)–corrected input images, which provide more complete star finding as well as more reliable photometry for the NUV bands, which had no CTE correction in the previous version of the PHAT photometry. While this method requires significantly more computing resources and time than earlier versions where the photometry was performed on individual pointings, it results in smaller systematic instrumental completeness variations as demonstrated by cleaner maps in stellar density, and it results in optimal constraints on stellar fluxes in all bands from the survey data. Our resulting catalog has 138 million stars, 18% more than the previous catalog, with lower density regions gaining as much as 40% more stars. The new catalog produces nearly seamless population maps that show relatively well-mixed distributions for populations associated with ages older than 1–2 Gyr and highly structured distributions for the younger populations

Tables for: The Panchromatic Hubble Andromeda Treasury XXI. The Legacy Resolved Stellar Photometry Catalog

<p>This deposit contains the full machine-readable tables for the accepted version of the manuscript, "<em>The Panchromatic Hubble Andromeda Treasury XXI. The Legacy Resolved Stellar Photometry Catalog</em>", submitted and accepted to the Astrophysical Journal Supplments. </p> <p>The specific files included in this deposit are the full version of Tables 1-3 in this manuscript:</p> <ul> <li>Table 1: Simplified table of PHAT photometry for easy use;</li> <li>Table 2: Simplified table of artificial star test results for easy use;</li> <li>Table 3: Summary of artificial star statistics as a function of brightness and stellar density.</li> </ul> <p>The *.txt files are formatted according to the machine-readable standards adopted by the AAS Journals and CDS/Vizier. Documentation of this format can be found at these links:</p> <ul> <li><a href="https://journals.aas.org/mrt-overview/">AAS Journals MRT overview</a></li> <li><a href="http://vizier.u-strasbg.fr/doc/catstd.htx">CDS/Vizier standards</a></li> </ul> <p>These files can be read in python using the astropy package or with the most recent version of <a href="https://www.star.bris.ac.uk/~mbt/topcat/">TOPCAT</a> (> Version 4.8). An example script for reading these files in astropy is given here:</p> <pre><code class="language-python"> from astropy.table import Table data = Table.read("datafile3.txt", format="ascii.cds") </code></pre> <p>In addition, a headerless, compressed TeX (&-delimited; "full_table.tex.xz") version of Table 1, and a header-only, dataless version of Table 1 ("datafile1_headeronly.txt") are provided to give users additional tools for dealing with this large dataset. </p> <p>The compression routine was applied using xz <https://tukaani.org/xz/> with the encodings</p> <ul> <li> <p><code>xz -z -7 -T 0 full_table.tex</code></p> </li> <li> <p><code>xz -z -9 -T 0 datafile1.txt</code></p> </li> </ul> <p>The Table 1 files on Zenodo were then split into smaller chunks to upload them to Zenodo using the GNU <a href="https://www.gnu.org/software/coreutils/manual/html_node/split-invocation.html"><code>split</code></a> routine. The full files can be recovered by recombining them before decompressing them. The list of related commands and the expected md5 hexidecimal checksums are given here:</p> <ul> <li> <p><code>split --bytes=512M ../full_table.tex.xz full_table.tex.xz.</code></p> </li> <li> <p><code>split --bytes=512M ../datafile1.txt.xz datafile1.txt.xz.</code></p> </li> <li> <p><code>cat full_table.tex.xz.a* > full_table.tex.xz</code></p> </li> <li> <p><code>cat datafile1.txt.xz.a* > datafile1.txt.xz</code></p> </li> <li> <p><code>MD5 (full_table.tex.xz) = 7f9195210bec61c08d04926ada4a021a</code></p> </li> <li> <p><code>MD5 (datafile1.txt.xz) = 63205fe1051e97f4e04380dd23469893</code></p> </li> </ul> <p>Finally, those interested in generating their own cuts from the DOLPHOT quality parameters can access the full photometry tables, available at MAST as a High Level Science Product via <a href="https://doi.org/10.17909/T91S30">doi.org/10.17909/T91S30</a></p>The MRT versions of Tables 2 and 3 are also available through the published article. The MRT version of Table 1 (datafile1.txt) is only available at this deposit due to its size. Support for this work was provided by NASA through grant GO-12055 from the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555