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1. The Spitzer–HETDEX Exploratory Large-Area Survey. IV. Model-based Multiwavelength Photometric Catalog

   https://doi.org/10.3847/1538-4365/acfe78  

   Leung, Gene C. K. ; Finkelstein, Steven L. ; Weaver, John R. ; Papovich, Casey ; Larson, Rebecca L. ; Chworowsky, Katherine ; Ciardullo, Robin ; Gawiser, Eric ; Gronwall, Caryl ; Jogee, Shardha ; et al ( November 2023 , The Astrophysical Journal Supplement Series)

   We present a 0.3–4.5μm 16-band photometric catalog for the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers an ∼27 deg²field within the footprint of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX). Here we present new DECam imaging and anrizK_sband–selected catalog of four million sources extracted using a fully model-based approach. We validate our photometry by comparing with the model-based DECam Legacy Survey. We analyze the differences between model-based and aperture photometry by comparing with the previous SHELA catalog, finding that our model-based photometry can measure point sources to fainter fluxes and better capture the full emission of resolved sources. The catalog is 80% (50%) complete atriz∼ 24.7 (25.1) AB mag, and the optical photometry reaches a 5σdepth of ∼25.5 AB mag. We measure photometric redshifts and achieve a 1σscatter of Δz/(1 +z) of 0.04 with available spectroscopic redshifts at 0 ≤z≤ 1. This large-area, multiwavelength photometric catalog, combined with spectroscopic information from HETDEX, will enable a wide range of extragalactic science investigations.

    

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2. Systematic Differences in the Calculation of Stellar Mass for ALFALFA Galaxies

   Burhenne, Clare ( January 2019 , American Astronomical Society, AAS Meeting)

   To create a Baryonic Tully-Fisher Relationship (BTFR) for the ALFALFA galaxies, we require a corresponding catalog of optical photometry to produce reliable stellar masses to complement their HI masses. Different methods of calculating stellar mass have been used in derivations of the BTFR depending on the sky distribution, prior redshift information or multiwavelength photometry of the sample galaxies. In order to obtain stellar masses for all of the ALFALFA galaxies in the SDSS photometric footprint, we use a crossmatch file between the α-100 catalog and the SDSS DR14 database to produce a reliable catalog of optical photometric properties for use in the stellar mass calculation and inclination-dependent corrections. For the stellar masses, we use the methodology set forth in Taylor et al. (2011), specifically, the modeled mass to light ratio estimated from the g-i color index. In order to compare stellar masses derived in this way with results obtained by other authors in the literature who used Petrosian and Sersic masses available in the NASA Sloan Atlas (NSA) to derive stellar masses, we investigate the differences in stellar mass and the corrections for inclination and extinction between values complied in the NSA and ones obtained using our α-100-SDSS cross-match. We investigate systematic differences in stellar mass estimates based on photometric properties such as color, surface brightness and concentration and on others such as distance, velocity width and HI richness. This research is supported by the Brinson Foundation for the Arecibo Pieces-Perseus Supercluster Survey (APPSS) and NSF grant NSF/AST-1714828 to M.P. Haynes. 

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3. Revealing the Field Sub-subgiant Population Using a Catalog of Active Giant Stars and Gaia EDR3

   https://doi.org/10.3847/1538-4357/ac53b1  

   Leiner, Emily M. ; Geller, Aaron M. ; Gully-Santiago, Michael A. ; Gosnell, Natalie M. ; Tofflemire, Benjamin M. ( March 2022 , The Astrophysical Journal)

   Sub-subgiant stars (SSGs) fall below the subgiant branch and/or red of the giant branch in open and globular clusters, an area of the color–magnitude diagram (CMD) not populated by standard stellar evolution tracks. One hypothesis is that SSGs result from rapid rotation in subgiants or giants due to tidal synchronization in a close binary. The strong magnetic fields generated inhibit convection, which in turn produces large starspots, radius inflation, and lower-than-expected average surface temperatures and luminosities. Here we cross-reference a catalog of active giant binaries (RS CVns) in the field with Gaia EDR3. Using the Gaia photometry and parallaxes, we precisely position the RS CVns in a CMD. We identify stars that fall below a 14 Gyr, metal-rich isochrone as candidate field SSGs. Out of a sample of 1723 RS CVn, we find 448 SSG candidates, a dramatic expansion from the 65 SSGs previously known. Most SSGs have rotation periods of 2–20 days, with the highest SSG fraction found among RS CVn with the shortest periods. The ubiquity of SSGs among this population indicates that SSGs are a normal phase in evolution for RS CVn-type systems, not rare by-products of dynamical encounters found only in dense star clusters as some have suggested. We present our catalog of 1723 active giants, including Gaia photometry and astrometry, and rotation periods from the Transiting Exoplanet Survey Satellite and International Variable Star Index (VSX). This catalog can serve as an important sample to study the impacts of magnetic fields in evolved stars.

    

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4. Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog

   https://doi.org/10.3847/1538-4357/acbb6f  

   Rodriguez, Antonio C. ; Kulkarni, Shrinivas R. ; Prince, Thomas A. ; Szkody, Paula ; Burdge, Kevin B. ; Caiazzo, Ilaria ; van Roestel, Jan ; Vanderbosch, Zachary P. ; El-Badry, Kareem ; Bellm, Eric C. ; et al ( March 2023 , The Astrophysical Journal)

   Abstract Magnetic cataclysmic variables (CVs) are luminous Galactic X-ray sources, which have been difficult to find in purely optical surveys due to their lack of outburst behavior. The eROSITA telescope on board the Spektr-RG mission is conducting an all-sky X-ray survey and recently released the public eROSITA Final Equatorial Depth Survey (eFEDS) catalog. We crossmatched the eFEDS catalog with photometry from the Zwicky Transient Facility and discovered two new magnetic CVs. We obtained high-cadence optical photometry and phase-resolved spectroscopy for each magnetic CV candidate and found them both to be polars. Among the newly discovered magnetic CVs is eFEDS J085037.2+044359/ZTFJ0850+0443, an eclipsing polar with orbital period P orb = 1.72 hr and WD mass M WD = 0.81 ± 0.08 M ⊙ . We suggest that eFEDS J085037.2+044359/ZTFJ0850+0443 is a low magnetic field strength polar, with B WD ≲ 10 MG. We also discovered a non-eclipsing polar, eFEDS J092614.1+010558/ZTFJ0926+0105, with orbital period P orb = 1.47 hr and magnetic field strength B WD = 36–42 MG. 

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5. HEROES: The Hawaii eROSITA Ecliptic Pole Survey Catalog

   https://doi.org/10.3847/1538-4365/accd70  

   Taylor, A. J. ; Barger, A. J. ; Cowie, L. L. ; Hasinger, G. ; Hu, E. M. ; Songaila, A. ( May 2023 , The Astrophysical Journal Supplement Series)

   We present a seven-band (g,r,i,z,y, NB816, NB921) catalog derived from a Subaru Hyper Suprime-Cam (HSC) imaging survey of the North Ecliptic Pole (NEP). The survey, known as HEROES, consists of 44 deg²of contiguous imaging reaching median 5σdepths ofg: 26.5,r: 26.2,i: 25.7,z: 25.1,y: 23.9, NB816: 24.4, and NB921: 24.4 mag. We reduced these data with the HSC pipeline softwarehscPipe, and produced a resulting multiband catalog containing over 25 million objects. We provide the catalog in three formats: (1) a collection ofhscPipeformat forced photometry catalogs, (2) a single combined catalog containing every object in that data set with selected useful columns, and (3) a smaller variation of the combined catalog with only essential columns for basic analysis or low-memory machines. The catalog uses all the available HSC data on the NEP and may serve as the primary optical catalog for current and future NEP deep fields from instruments and observatories such as SCUBA-2, eROSITA, Spitzer, Euclid, and JWST.

    

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