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This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We present Hubble Space Telescope imaging of 14 gas-rich, low-surface-brightness galaxies in the field at distances of 25–36 Mpc, with mean effective radii and g-band central surface brightnesses of 1.9 kpc and 24.2 mag arcsec−2. Nine meet the standard criteria to be considered ultra-diffuse galaxies (UDGs). An inspection of point-like sources brighter than the turnover magnitude of the globular cluster luminosity function and within twice the half-light radii of each galaxy reveals that, unlike those in denser environments, gas-rich, field UDGs host very few old globular clusters (GCs). Most of the targets (nine) have zero candidate GCs, with the remainder having one or two candidates each. These findings are broadly consistent with expectations for normal dwarf galaxies of similar stellar mass. This rules out gas-rich, field UDGs as potential progenitors of the GC-rich UDGs that are typically found in galaxy clusters. However, some in galaxy groups may be directly accreted from the field. In line with other recent results, this strongly suggests that there must be at least two distinct formation pathways for UDGs, and that this subpopulation is simply an extreme low surface brightness extension of the underlying dwarf galaxy population. The root cause of their diffuse stellar distributions remains unclear, but the formation mechanism appears to only impact the distribution of stars (and potentially dark matter), without strongly impacting the distribution of neutral gas, the overall stellar mass, or the number of GCs. © 2022. The Author(s). Published by the American Astronomical Society., This work is based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with program # HST-SNAP-16758. Support for program # HST-SNAP-16758 was provided by NASA through a grant from the Space Telescope Science Institute. This work used images from the Dark Energy Camera Legacy Survey (DECaLS; Proposal ID 2014B-0404; PIs: David Schlegel and Arjun Dey). Full acknowledgment can be found at https://www.legacysurvey.org/acknowledgment/. D.J.S. acknowledges support from NSF grant Nos. AST-1821967 and 1813708. K.S. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). A.K. acknowledges financial support from the grant (SEV-2017-0709) funded by MCIN/AEI/10.13039/501100011033 and from the grant POSTDOC_21_00845 funded by the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia. L.L. acknowledges support from NSF grant No. AST-2045371., With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We use panoramic optical spectroscopy obtained with the Very Large Telescope/MUSE to investigate the nature of five candidate extremely isolated low-mass star-forming regions (Blue Candidates; hereafter, BCs) toward the Virgo cluster of galaxies. Four of the five (BC1, BC3, BC4, and BC5) are found to host several H ii regions and to have radial velocities fully compatible with being part of the Virgo cluster. All the confirmed candidates have mean metallicity significantly in excess of that expected from their stellar mass, indicating that they originated from gas stripped from larger galaxies. In summary, these four candidates share the properties of the prototype system SECCO 1, suggesting the possible emergence of a new class of stellar systems, intimately linked to the complex duty cycle of gas within clusters of galaxies. A thorough discussion of the nature and evolution of these objects is presented in a companion paper, where the results obtained here from the MUSE data are complemented with Hubble Space Telescope (optical) and Very Large Array (Hi) observations. © 2022. The Author(s). Published by the American Astronomical Society., M.B. acknowledges the financial support of INAF—OAS Bologna, through the Ob. F. 1.05.01.01—Ricerca di Base funds. D.J.S. acknowledges support from NSF grants AST-1821967 and 1813708. A.K. acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities, through the "Center of Excellence Severo Ochoa" awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), and through the grant POSTDOC_21_00845, financed from budgetary program 54a Scientific Research and Innovation of the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia. E.A.K.A. is supported by the WISE research program, which is financed by the Dutch Research Council (NWO). R.R.M. gratefully acknowledges support from the ANID BASAL project FB210003. K.S. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). B.M.P. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST2001663. J.M.C., J.F., and J.L.I. are supported by NSF/AST grant 2009894. G.B. acknowledges support from the Agencia Estatal de Investigación del Ministerio de Ciencia en Innovación (AEI-MICIN) and the European Regional Development Fund (ERDF), under grants CEX2019-000920-S and PID2020-118778GB-I00/10.13039/501100011033.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We report the discovery of Tucana B, an isolated ultra-faint dwarf galaxy at a distance of D = 1.4 Mpc. Tucana B was found during a search for ultra-faint satellite companions to the known dwarfs in the outskirts of the Local Group, although its sky position and distance indicate the nearest galaxy to be ∼500 kpc distant. Deep ground-based imaging resolves Tucana B into stars, and it displays a sparse red giant branch consistent with an old, metal-poor stellar population analogous to that seen in the ultra-faint dwarf galaxies of the Milky Way, albeit at fainter apparent magnitudes. Tucana B has a half-light radius of 80 ± 40 pc and an absolute magnitude of ${M}_{V}=-{6.9}_{-0.6}^{+0.5}$ mag (${L}_{V}=({5}_{-2}^{+4})\times {10}^{4}$ L⊙), which is again comparable to the Milky Way's ultra-faint satellites. There is no evidence for a population of young stars, either in the optical color–magnitude diagram or in GALEX archival ultraviolet imaging, with the GALEX data indicating $\mathrm{log}({\mathrm{SFR}}_{\mathrm{NUV}}/{M}_{\odot }\,{\mathrm{yr}}^{-1})\lt -5.4$ for star formation on ≲100 Myr timescales. Given its isolation and physical properties, Tucana B may be a definitive example of an ultra-faint dwarf that has been quenched by reionization, providing strong confirmation of a key driver of galaxy formation and evolution at the lowest mass scales. It also signals a new era of ultra-faint dwarf galaxy discovery at the extreme edges of the Local Group. © 2022. The Author(s). Published by the American Astronomical Society., D.J.S. acknowledges support from NSF grants AST-1821967 and 1813708. B.M.P. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2001663. Research by D.C. is supported by NSF grant AST-1814208. A.K. acknowledges financial support from the State Agency for Research of the Spanish Ministry of Science, Innovation and Universities through the "Center of Excellence Severo Ochoa" awarded to the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and through the grant POSTDOC_21_00845 financed from the budgetary program 54a Scientific Research and Innovation of the Economic Transformation, Industry, Knowledge and Universities Council of the Regional Government of Andalusia. F.W. thanks the support provided by NASA through the NASA Hubble Fellowship grant #HF2-51448 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. A.C. is supported by a Brinson Prize Fellowship at UChicago/KICP. K.S. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC).

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., The two sources AGC 226178 and NGVS 3543, an extremely faint, clumpy, blue stellar system and a low surface brightness dwarf spheroidal, are adjacent systems in the direction of the Virgo cluster. Both have been studied in detail previously, with it being suggested that they are unrelated normal dwarf galaxies or that NGVS 3543 recently lost its gas through ram pressure stripping and AGC 226178 formed from this stripped gas. However, with Hubble Space Telescope Advanced Camera for Surveys imaging, we demonstrate that the stellar population of NGVS 3543 is inconsistent with being at the distance of the Virgo cluster and that it is likely a foreground object at approximately 10 Mpc, whereas the stellar population of AGC 226178 is consistent with it being a very young (10–100 Myr) object in the Virgo cluster. Through a reanalysis of the original ALFALFA H i detection, we show that AGC 226178 likely formed from gas stripped from the nearby dwarf galaxy VCC 2034, a hypothesis strengthened by the high metallicity measured with MUSE VLT observations. However, it is unclear whether ram pressure or a tidal interaction is responsible for stripping the gas. Object AGC 226178 is one of at least five similar objects now known toward Virgo. These objects are all young and unlikely to remain visible for over ∼500 Myr, suggesting that they are continually produced in the cluster. © 2022. The Author(s). Published by the American Astronomical Society., This work is based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with program No. HST-GO-15183. Support for program No. HST-GO-15183 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. It is also based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO program 0101.B-0376A. This work used archival data from the Karl G. Jansky Very Large Array. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The data were observed as part of program 13A-028 (PI: J. Cannon). The work used images from the Dark Energy Camera Legacy Survey (DECaLS; proposal ID 2014B-0404; PIs: David Schlegel and Arjun Dey). Full acknowledgment at https://www.legacysurvey.org/acknowledgment/. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS website is http://www.sdss.org/. D.J.S. acknowledges support from NSF grants AST-1821967 and 1813708. M.B. acknowledges financial support of this research from INAF Main Stream grant 1.05.01.86.28 assigned to the program The Smallest Scale of the Hierarchy (SSH). K.S. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). B.M.P. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2001663. E.A.K.A. is supported by the WISE research program, which is financed by the Dutch Research Council (NWO). G.B. acknowledges financial support through grant (AEI/FEDER, UE) AYA2017-89076-P, as well as by the Ministerio de Ciencia, Innovación y Universidades through the state budget and by the Consejería de Economía, Industria, Comercio y Conocimiento of the Canary Islands Autonomous Community through the regional budget. J.S. acknowledges support from the Packard Foundation. M.P.H. acknowledges support from NSF/AST-1714828 and grants from the Brinson Foundation. J.M.C., J.F., and J.L.I. are supported by NST/AST 2009894. R.R.M. gratefully acknowledges support from project ANID PIA/BASAL FB210003. Research by D.C. is supported by NSF grant AST-1814208. AK acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709).

We report the discovery of six ultra-faint Milky Way satellites discovered through matched-filter searches conducted using Dark Energy Camera (DECam) data processed as part of the second data release of the DECam Local Volume Exploration (DELVE) survey. Leveraging deep Gemini/GMOS-N imaging (for four candidates) as well as follow-up DECam imaging (for two candidates), we characterize the morphologies and stellar populations of these systems. We find that these candidates all share faint absolute magnitudes ($M_{V} \geq -3.2$ mag) and old, metal-poor stellar populations ($\tau > 10$ Gyr, [Fe/H] $< -1.4$ dex). Three of these systems are more extended ($r_{1/2} > 15$ pc), while the other three are compact ($r_{1/2} < 10$ pc). From these properties, we infer that the former three systems (Bo\"{o}tes V, Leo Minor I, and Virgo II) are consistent with ultra-faint dwarf galaxy classifications, whereas the latter three (DELVE 3, DELVE 4, and DELVE 5) are likely ultra-faint star clusters. Using data from the Gaia satellite, we confidently measure the proper motion of Bo\"{o}tes V, Leo Minor I, and DELVE 4, and tentatively detect a proper motion signal from DELVE 3 and DELVE 5; no signal is detected for Virgo II. We use these measurements to explore possible associations between the newly-discovered systems and the Sagittarius dwarf spheroidal, the Magellanic Clouds, and the Vast Polar Structure, finding several plausible associations. Our results offer a preview of the numerous ultra-faint stellar systems that will soon be discovered by the Vera C. Rubin Observatory and highlight the challenges of classifying the faintest stellar systems., Comment: 30 pages, 12 Figures (including Appendix). Submitted to ApJ. We encourage the reader to also review Smith et al. 2022, "Discovery of a new Local Group Dwarf Galaxy Candidate in UNIONS: Bo\"{o}tes V" (arxiv: 2209.08242), who independently present the discovery of one of the candidates reported here. We are working to make code and data products available

We compare the star-forming properties of satellites around Milky Way (MW) analogs from the Stage~II release of the Satellites Around Galactic Analogs Survey (SAGA-II) to those from the APOSTLE and Auriga cosmological zoom-in simulation suites. We use archival GALEX UV imaging as a star-formation indicator for the SAGA-II sample and derive star-formation rates (SFRs) to compare with those from APOSTLE and Auriga. We compare our detection rates from the NUV and FUV bands to the SAGA-II H$\alpha$ detections and find that they are broadly consistent with over $85\%$ of observed satellites detected in all three tracers. We apply the same spatial selection criteria used around SAGA-II hosts to select satellites around the MW-like hosts in APOSTLE and Auriga. We find very good overall agreement in the derived SFRs for the star-forming satellites as well as the number of star-forming satellites per host in observed and simulated samples. However, the number and fraction of quenched satellites in the SAGA-II sample are significantly lower than those in APOSTLE and Auriga below a stellar mass of $M_*\sim10^{8}\,M_{\odot}$, even when the SAGA-II incompleteness and interloper corrections are included. This discrepancy is robust with respect to the resolution of the simulations and persists when alternative star-formation tracers are employed. We posit that this disagreement is not readily explained by vagaries in the observed or simulated samples considered here, suggesting a genuine discrepancy that may inform the physics of satellite populations around MW analogs., Comment: Accepted for publication in ApJ Letters after minor changes to text

We present a preview of the faint dwarf galaxy discoveries that will be possible with the Vera C. Rubin Observatory and Subaru Hyper Suprime-Cam in the next decade. In this work, we combine deep ground-based images from the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS) and extensive image simulations to investigate the recovery of faint, resolved dwarf galaxies in the Local Volume with a matched-filter technique. We adopt three fiducial distances - 1.5, 3.5, 5 Mpc, and quantitatively evaluate the effects on dwarf detection of varied stellar backgrounds, ellipticity, and Milky Way foreground contamination and extinction. We show that our matched-filter method is powerful for identifying both compact and extended systems, and near-future surveys will be able to probe at least ~4.5 mag below the tip of the red giant branch (TRGB) for a distance of up to 1.5 Mpc, and ~2 mag below the TRGB at 5 Mpc. This will push the discovery frontier for resolved dwarf galaxies to fainter magnitudes, lower surface brightnesses, and larger distances. Our simulations show the secure census of dwarf galaxies down to $M_{V}$$\approx$-5, -7, -8, will be soon within reach, out to 1.5 Mpc, 3.5 Mpc, and 5 Mpc, respectively, allowing us to quantify the statistical fluctuations in satellite abundances around hosts, and parse environmental effects as a function of host properties., Submitted to AAS journals. Comments are welcome

We have followed up two ultra-diffuse galaxies (UDGs), detected adjacent to stellar streams, with Hubble Space Telescope (HST) imaging and HI mapping with the Jansky Very Large Array (VLA) in order to investigate the possibility that they might have a tidal origin. With the HST F814W and F555W images we measure the globular cluster (GC) counts for NGC 2708-Dw1 and NGC 5631-Dw1 as $2^{+1}_{-1}$ and $5^{+1}_{-2}$, respectively. NGC 2708-Dw1 is undetected in HI down to a 3$\sigma$ limit of $\log (M_\mathrm{HI}/\mathrm{M_\odot}) = 7.3$, and there is no apparent HI associated with the nearby stellar stream. There is a 2$\sigma$ HI feature coincident with NGC 5631-Dw1. However, this emission is blended with a large gaseous tail emanating from NGC 5631 and is not necessarily associated with the UDG. The presence of any GCs and the lack of clear HI connections between the UDGs and their parent galaxies strongly disfavor a tidal dwarf galaxy origin, but cannot entirely rule it out. The GC counts are consistent with those of normal dwarf galaxies, and the most probable formation mechanism is one where these UDGs were born as normal dwarfs and were later tidally stripped and heated. We also identify an over-luminous ($M_\mathrm{V} = -11.1$) GC candidate in NGC 2708-Dw1, which may be a nuclear star cluster transitioning to an ultra-compact dwarf as the surrounding dwarf galaxy gets stripped of stars., Comment: Accepted to ApJ

Full list of authors: Cerny, W.; Pace, A. B.; Drlica-Wagner, A.; Ferguson, P. S.; Mau, S.; Adamów, M.; Carlin, J. L.; Choi, Y.; Erkal, D.; Johnson, L. C.; Li, T. S.; Martínez-Vázquez, C. E.; Mutlu-Pakdil, B.; Nidever, D. L.; Olsen, K. A. G.; Pieres, A.; Tollerud, E. J.; Simon, J. D.; Vivas, A. K.; James, D. J.; Kuropatkin, N.; Majewski, S.; Martínez-Delgado, D.; Massana, P.; Miller, A. E.; Neilsen, E. H.; Noël, N. E. D.; Riley, A. H.; Sand, D. J.; Santana-Silva, L.; Stringfellow, G. S.; Tucker, D. L.; DELVE Collaboration., We report the discovery of a new ultra-faint stellar system found near the Magellanic Clouds in the DECam Local Volume Exploration Survey. This new system, DELVE J0155-6815 (DELVE 2), is located at a heliocentric distance of D o˙ = 71 4 kpc, which places it at a 3D physical separation of 12 3 kpc from the center of the Small Magellanic Cloud and 28 -3 +4, kpc from the center of the Large Magellanic Cloud (LMC). DELVE 2 is identified as a resolved overdensity of old (τ > 13.3 Gyr) and metal-poor ( dex) stars with a projected half-light radius of and an absolute magnitude of M V =-{2.1} {-0.5} {+0.4}, mag. The size and luminosity of DELVE 2 are consistent with both the population of recently discovered ultra-faint globular clusters and the smallest ultra-faint dwarf galaxies. However, its photometrically derived age and metallicity would place it among the oldest and most metal-poor globular clusters in the Magellanic system. In the absence of spectroscopic measurements of the system's metallicity dispersion and internal kinematics, we are unable to conclusively classify this system at this time. DELVE 2 is detected in Gaia DR2 with a clear proper-motion signal, with multiple blue horizontal-branch stars near the centroid of the system with proper motions consistent with the systemic mean. We measure the system proper motion to be μ α δ, μ δ = 1.02 -0.25 {+0.24}, -{0.85}_{-0.19} {+0.18}) mas yr-1. We compare the spatial position and proper motion of DELVE 2 with simulations of the accreted satellite population of the LMC and find that it is very likely to be associated with the LMC. © 2021. The American Astronomical Society. All rights reserved., W. C. acknowledges support from the University of Chicago Liew Family Research Fellowship. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internships (SULI) program. The DELVE project is partially supported by Fermilab LDRD project L2019-011 and the NASA Fermi Guest Investigator Program Cycle 9 No. 91201. A. B. P. acknowledges support from NSF grant AST-1813881. This research received support from the National Science Foundation (NSF) under grant No. NSF DGE-1656518 through the NSF Graduate Research Fellowship received by S.M. J. L. C. acknowledges support from NSF grant AST-1816196. J.D.S. acknowledges support from NSF grant AST-1714873. S. R. M. acknowledges support from NSF grant AST-1909497. D. M. D. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Centre of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the DOE and NSF (USA), MISE (Spain), STFC (UK), HEFCE (UK), NCSA (UIUC), KICP (U. Chicago), CCAPP (Ohio State), MIFPA (Texas A&M University), CNPQ, FAPERJ, FINEP (Brazil), MINECO (Spain), DFG (Germany), and the collaborating institutions in the Dark Energy Survey, which are Argonne Lab, UC Santa Cruz, University of Cambridge, CIEMAT-Madrid, University of Chicago, University College London, DES-Brazil Consortium, University of Edinburgh, ETH Zurich, Fermilab, University of Illinois, ICE (IEECCSIC), IFAE Barcelona, Lawrence Berkeley Lab, LMU Munchen and the associated Excellence Cluster Universe, University of Michigan, NSF's National Optical-Infrared Astronomy Research Laboratory, University of Nottingham, Ohio State University, OzDES Membership Consortium, University of Pennsylvania, University of Portsmouth, SLAC National Lab, Stanford University, University of Sussex, and Texas A&M University. Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This manuscript has been authored by the Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics.

We present deep Hubble Space Telescope (HST) imaging of five faint dwarf galaxies associated with the nearby spiral NGC 253 (D ≈ 3.5 Mpc). Three of these are newly discovered dwarf galaxies, while all five were found in the Panoramic Imaging Survey of Centaurus and Sculptor, a Magellan+Megacam survey to identify faint dwarfs and other substructures in resolved stellar light around massive galaxies outside of the Local Group. Our HST data reach ≳3 magnitudes below the tip of the red giant branch for each dwarf, allowing us to derive their distances, structural parameters, and luminosities. All five systems contain mostly old, metal-poor stellar populations (age ∼12 Gyr, [M/H] ≲ −1.5) and have sizes (r h ∼ 110–3000 pc) and luminosities (M V ∼ −7 to −12 mag) largely consistent with Local Group dwarfs. The three new NGC 253 satellites are among the faintest systems discovered beyond the Local Group. We also use archival H i data to place limits on the gas content of our discoveries. Deep imaging surveys such as our program around NGC 253 promise to elucidate the faint end of the satellite luminosity function and its scatter across a range of galaxy masses, morphologies, and environments in the decade to come.

We perform consistent reductions and measurements for three ultra-faint dwarf galaxies (UFDs):Bo ̈otes I, Leo IV and Leo V. Using the public archival data from the GIRAFFE spectrograph on theVery Large Telescope (VLT), we locate new members and provide refined measurements of physicalparameters for these dwarf galaxies. We identify nine new Leo IV members and four new Leo Vmembers, and perform a comparative analysis of previously discovered members. Additionally, weidentify one new binary star in both Leo IV and Leo V. After removing binary stars, we recalculatethe velocity dispersions of Bo ̈otes I and Leo IV to be 5.1+0.7−0.8and 3.4+1.3−0.9km s−1, respectively; Wedo not resolve the Leo V velocity dispersion. We identify a weak velocity gradient in Leo V thatis∼4×smaller than the previously calculated gradient and that has a corresponding position anglewhich differs from the literature value by∼120 deg. Combining the VLT data with previous literature,we re-analyze the Bo ̈otes I metallicity distribution function and find that a model including infall ofpristine gas while Bo ̈otes I was forming stars best fits the data. Our analysis of Leo IV, Leo V andother UFDs will enhance our understanding of these enigmatic stellar populations and contribute tofuture dark matter studies. This is the first in a series of papers examining thirteen UDFs observedwith VLT/GIRAFFE between 2009 and 2017. Similar analyses of the remaining ten UFDs will bepresented in forthcoming papers

Full list of authors: Cerny, W.; Pace, A. B.; Drlica-Wagner, A.; Koposov, S. E.; Vivas, A. K.; Mau, S.; Riley, A. H.; Bom, C. R.; Carlin, J. L.; Choi, Y.; Erkal, D.; Ferguson, P. S.; James, D. J. ; Li, T. S.; Martínez-Delgado, D.; Martínez-Vázquez, C. E.; Munoz, R. R.; Mutlu-Pakdil, B.; Olsen, K. A. G.; Pieres, A.; Sakowska, J. D.; Sand, D. J.; Simon, J. D.; Smercina, A.; Stringfellow, G. S.; Tollerud, E. J.; Adamów, M.; Hernandez-Lang, D.;Kuropatkin, N.; Santana-Silva, L.; Tucker, D. L.; Zenteno, A.; Delve Collaboration., We present the discovery of a candidate ultra-faint Milky-Way satellite, Eridanus IV (DELVE J0505-0931), detected in photometric data from the DECam Local Volume Exploration survey (DELVE). Eridanus IV is a faint (MV = - 4.7 ± 0.2), extended ( = - r 75+ pc 1 2 13 16 ), and elliptical (ò = 0.54 ± 0.1) system at a heliocentric distance of - 76.7+ kpc 6.1 4.0 , with a stellar population that is well described by an old, metal-poor isochrone (age of τ ∼ 13.0 Gyr and metallicity of [Fe/H] - 2.1 dex). These properties are consistent with the known population of ultra-faint Milky-Way satellite galaxies. Eridanus IV is also prominently detected using proper-motion measurements from Gaia Early Data Release 3, with a systemic proper motion of (ma cos d, md) = (+0.25 0.06, -0.10 0.05) mas yr-1 measured from its horizontal branch and red-giant-branch member stars. We find that the spatial distribution of likely member stars hints at the possibility that the system is undergoing tidal disruption. © 2021 Institute of Physics Publishing. All rights reserved., The DELVE project is partially supported by Fermilab LDRD project L2019-011 and the NASA Fermi Guest Investigator Program Cycle 9 No. 91201. A.B.P. acknowledges support from NSF grant AST-1813881. This research received support from the National Science Foundation (NSF) under grant No. NSF DGE-1656518 through the NSF Graduate Research Fellowship received by S.M. B.M.P. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-2001663. J.L.C. acknowledges support from NSF grant AST-1816196. J.D.S. acknowledges support from NSF grant AST-1714873. S.R.M. acknowledges support from NSF grant AST-1909497. D.M.D. acknowledges financial support from the Talentia Senior Program (through the incentive ASE-136) from Secretaria General de Universidades, Investigacion y Tecnologia, de la Junta de Andalucia. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the DOE and NSF (USA), MISE (Spain), STFC (UK), HEFCE (UK), NCSA (UIUC), KICP (U. Chicago), CCAPP (Ohio State), MIFPA (Texas A&M University), CNPQ, FAPERJ, FINEP (Brazil), MINECO (Spain), DFG (Germany), and the collaborating institutions in the Dark Energy Survey, which are Argonne Lab, UC Santa Cruz, University of Cambridge, CIEMAT-Madrid, University of Chicago, University College London, DES-Brazil Consortium, University of Edinburgh, ETH Zurich, Fermilab, University of Illinois, ICE (IEEC-CSIC), IFAE Barcelona, Lawrence Berkeley Lab, LMU Munchen, and the associated Excellence Cluster Universe, University of Michigan, NSF's National Optical-Infrared Astronomy Research Laboratory, University of Nottingham, Ohio State University, OzDES Membership Consortium University of Pennsylvania, University of Portsmouth, SLAC National Lab, Stanford University, University of Sussex, and Texas A&M University. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This manuscript has been authored by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.

We report the discovery of a $>1^\circ$ ($\sim50$ kpc) long stellar tidal stream emanating from the dwarf galaxy DDO 44, a likely satellite of Local Volume galaxy NGC 2403 located $\sim70$ kpc in projection from its companion. NGC 2403 is a roughly Large Magellanic Cloud stellar-mass galaxy 3 Mpc away, residing at the outer limits of the M 81 group. We are mapping a large region around NGC 2403 as part of our MADCASH (Magellanic Analogs' Dwarf Companions and Stellar Halos) survey, reaching point source depths (90% completeness) of ($g, i$) = (26.5, 26.2). Density maps of old, metal-poor RGB stars reveal tidal streams extending on two sides of DDO 44, with the streams directed toward NGC 2403. We estimate total luminosities of the original DDO 44 system (dwarf and streams combined) to be $M_{i, \rm{tot}} = -13.4$ and $M_{g, \rm{tot}} = -12.6$, with $\sim25-30\%$ of the luminosity in the streams. Analogs of $\sim$LMC-mass hosts with massive tidally disrupting satellites are rare in the Illustris simulations, especially at large separations such as that of DDO 44. The few analogs that are present in the models suggest that even low-mass hosts can efficiently quench their massive satellites., Accepted for publication in ApJ. Updated with minor changes in response to referee

We have obtained deep Hubble Space Telescope (HST) imaging of 19 dwarf galaxy candidates in the vicinity of M101. Advanced Camera for Surveys HST photometry for 2 of these objects showed resolved stellar populations and Tip of the Red Giant Branch derived distances consistent with M101 group membership. The other 17 were found to have no resolved stellar populations, meaning they are background low surface brightness (LSB) galaxies. It is notable that many LSB objects which had previously been assumed to be M101 group members based on projection have been shown to be background objects, indicating the need for future diffuse dwarf surveys to be careful in drawing conclusions about group membership without robust distance estimates. In this work we update the satellite luminosity function of M101 based on the presence of these new objects down to M_V=-8.2. M101 is a sparsely populated system with only 9 satellites down to M_V~-8, as compared to 26 for M31 and 24.5\pm7.7 for the median local Milky Way (MW)-mass host. This makes M101 the sparsest group probed to this depth, though M94 is even sparser to the depth it has been examined (M_V=-9.1). M101 and M94 share several properties that mark them as unusual compared to the other local MW-mass galaxies examined: they have a sparse satellite population but also have high star forming fractions among these satellites; such properties are also found in the galaxies examined as part of the SAGA survey. We suggest that these properties appear to be tied to the galactic environment, with more isolated galaxies showing sparse satellite populations which are more likely to have had recent star formation, while those in dense environments have more satellites which tend to have no recent star formation. Overall our results show a level of halo-to-halo scatter between galaxies of similar mass that is larger than is predicted in the \LambdaCDM model., Comment: 23 pages, 10 figures, accepted by ApJ

We present a deep Hubble Space Telescope (HST) imaging study of two dwarf galaxies in the halos of Local Volume Large Magellanic Cloud (LMC) analogs. These dwarfs were discovered as part of our Subaru+Hyper Suprime-Cam MADCASH survey: MADCASH-1, which is a satellite of NGC 2403 (D~3.2 Mpc), and MADCASH-2, a previously unknown dwarf galaxy near NGC 4214 (D~3.0 Mpc). Our HST data reach >3.5 mag below the tip of the red giant branch (TRGB) of each dwarf, allowing us to derive their structural parameters and assess their stellar populations. We measure TRGB distances ($D=3.41^{+0.24}_{-0.23}$ Mpc for MADCASH-1, and $D=3.00^{+0.13}_{-0.15}$ Mpc for MADCASH-2), and confirm their associations with their host galaxies. MADCASH-1 is a predominantly old, metal-poor stellar system (age ~13.5 Gyr, [M/H] ~ -2.0), similar to many Local Group dwarfs. Modelling of MADCASH-2's CMD suggests that it contains mostly ancient, metal-poor stars (age ~13.5 Gyr, [M/H] ~ -2.0), but that ~10% of its stellar mass was formed 1.1--1.5 Gyr ago, and ~1% was formed 400--500 Myr ago. Given its recent star formation, we search MADCASH-2 for neutral hydrogen using the Green Bank Telescope, but find no emission and estimate an upper limit on the HI mass of $, 20 pages, 9 figures, 4 tables; minor edits to match accepted version published in ApJ

The ultra-faint dwarf galaxy Hercules has an extremely elongated morphology with both photometric overdensities and kinematic members at large radii, suggesting that it may be tidally disrupting due to a previous close encounter with the Milky Way. To explain its observational peculiarities, we present a deep Hubble Space Telescope (HST) imaging study of Hercules and its surrounding regions and investigate its tidal history through a careful search for a distance gradient along its stretched body. Our off-center HST data clearly resolve a main sequence, showing that the stellar extension seen along the major-axis of Hercules is genuine, not a clump of background galaxies. Utilizing Gaia DR2 data, we clean the region around Hercules of field contamination, and find four new plausible member stars, all of which are located at the outskirts of the dwarf galaxy. We update the distance to Hercules, and find $130.6\pm1.2$ kpc ($m-M=20.58\pm0.02$) for the main body, which is consistent with earlier estimates in the literature. While we find no conclusive evidence for a distance gradient, our work demonstrates that constraining a distance gradient in such a faint system is not trivial, and the possible thickness of the dwarf along the line of sight and field contamination make it harder to make decisive conclusions even with these high-precision data. Future studies coupled with tailored theoretical models are needed to understand the true nature of Hercules and of tidal distortion observables in ultra-faint galaxies in general., Comment: 17 pages, 7 figures, submitted to ApJ

We have obtained deep Hubble Space Telescope (HST) imaging of four faint and ultra-faint dwarf galaxy candidates in the vicinity of M101 - Dw21, Dw22, Dw23 and Dw35, originally discovered by Bennet et al. (2017). Previous distance estimates using the surface brightness fluctuation technique have suggested that these four dwarf candidates are the only remaining viable M101 satellites identified in ground based imaging out to the virial radius of M101 (D~250 kpc). Advanced Camera for Surveys imaging of all four dwarf candidates shows no associated resolved stellar populations, indicating that they are thus background galaxies. We confirm this by generating simulated HST color magnitude diagrams of similar brightness dwarfs at the distance of M101. Our targets would have displayed clear, resolved red giant branches with dozens of stars if they had been associated with M101. With this information, we construct a satellite luminosity function for M101, which is 90% complete to M_V=-7.7 mag and 50% complete to M_V=-7.4 mag, that extends into the ultra-faint dwarf galaxy regime. The M101 system is remarkably poor in satellites in comparison to the Milky Way and M31, with only eight satellites down to an absolute magnitude of M_V=-7.7 mag, compared to the 14 and 26 seen in the Milky Way and M31, respectively. Further observations of Milky Way analogs are needed to understand the halo-to-halo scatter in their faint satellite systems, and connect them with expectations from cosmological simulations., 9 Pages, 3 Figures, 1 Table, Accepted by ApJL

We report the discovery of two ultra-faint stellar systems found in early data from the DECam Local Volume Exploration survey (DELVE). The first system, Centaurus I (DELVE J1238-4054), is identified as a resolved overdensity of old and metal-poor stars with a heliocentric distance of ${\rm D}_{\odot} = 116.3_{-0.6}^{+0.6}$ kpc, a half-light radius of $r_h = 2.3_{-0.3}^{+0.4}$ arcmin, an age of $\tau > 12.85$ Gyr, a metallicity of $Z = 0.0002_{-0.0002}^{+0.0001}$, and an absolute magnitude of $M_V = -5.55_{-0.11}^{+0.11}$ mag. This characterization is consistent with the population of ultra-faint satellites, and confirmation of this system would make Centaurus I one of the brightest recently discovered ultra-faint dwarf galaxies. Centaurus I is detected in Gaia DR2 with a clear and distinct proper motion signal, confirming that it is a real association of stars distinct from the Milky Way foreground; this is further supported by the clustering of blue horizontal branch stars near the centroid of the system. The second system, DELVE 1 (DELVE J1630-0058), is identified as a resolved overdensity of stars with a heliocentric distance of ${\rm D}_{\odot} = 19.0_{-0.6}^{+0.5} kpc$, a half-light radius of $r_h = 0.97_{-0.17}^{+0.24}$ arcmin, an age of $\tau = 12.5_{-0.7}^{+1.0}$ Gyr, a metallicity of $Z = 0.0005_{-0.0001}^{+0.0002}$, and an absolute magnitude of $M_V = -0.2_{-0.6}^{+0.8}$ mag, consistent with the known population of faint halo star clusters. Given the low number of probable member stars at magnitudes accessible with Gaia DR2, a proper motion signal for DELVE 1 is only marginally detected. We compare the spatial position and proper motion of both Centaurus I and DELVE 1 with simulations of the accreted satellite population of the Large Magellanic Cloud (LMC) and find that neither is likely to be associated with the LMC., Comment: 17 pages, 6 figures, 1 table; updated to match published version; updated to address erratum

We present deep Magellan/Megacam stellar photometry of four recently discovered faint Milky Way satellites: Sagittarius II (Sgr II), Reticulum II (Ret II), Phoenix II (Phe II), and Tucana III (Tuc III). Our photometry reaches ~2-3 magnitudes deeper than the discovery data, allowing us to revisit the properties of these new objects (e.g., distance, structural properties, luminosity measurements, and signs of tidal disturbance). The satellite color-magnitude diagrams show that they are all old (~13.5 Gyr) and metal-poor ([Fe/H]$\lesssim-2.2$). Sgr II is particularly interesting as it sits in an intermediate position between the loci of dwarf galaxies and globular clusters in the size-luminosity plane. The ensemble of its structural parameters is more consistent with a globular cluster classification, indicating that Sgr II is the most extended globular cluster in its luminosity range. The other three satellites land directly on the locus defined by Milky Way ultra-faint dwarf galaxies of similar luminosity. Ret II is the most elongated nearby dwarf galaxy currently known for its luminosity range. Our structural parameters for Phe II and Tuc III suggest that they are both dwarf galaxies. Tuc III is known to be associated with a stellar stream, which is clearly visible in our matched-filter stellar density map. The other satellites do not show any clear evidence of tidal stripping in the form of extensions or distortions. Finally, we also use archival HI data to place limits on the gas content of each object., Comment: Accepted for publication in ApJ. Minor updates to match accepted version

We study the spiral arm morphology of a sample of the local spiral galaxies in the Illustris simulation and explore the supermassive black hole - galaxy connection beyond the bulge (e.g., spiral arm pitch angle, total stellar mass, dark matter mass, and total halo mass), finding good agreement with other theoretical studies and observational constraints. It is important to study the properties of supermassive black holes and their host galaxies through both observations and simulations and compare their results in order to understand their physics and formative histories.We find that Illustris prediction for supermassive black hole mass relative to pitch angle is in rather good agreement with observations and that barred and non-barred galaxies follow similar scaling relations. Our work shows that Illustris presents very tight correlations between supermassive black hole mass and large-scale properties of the host galaxy, not only for early-type galaxies but also low-mass, blue and star-forming galaxies. These tight relations beyond the bulge suggest that halo properties determine those of a disc galaxy and its supermassive black hole., Comment: 14 pages, 9 figures, 1 table

Aims: This work is the first stage of a campaign to search for IMBHs, in low luminosity AGN (LLAGN) and dwarf galaxies. An additional, and equally important, aim of this pilot study is to investigate the consistency between the predictions of several BH scaling relations and the fundamental plane of black hole activity (FP-BH). Methods: We use X-ray and radio luminosity relations in accreting BHs, along with the latest scaling relations between the mass of the central black hole (MBH) and the properties of its host spheroid, to predict MBH in seven LLAGN, that were previously reported to be in the IMBH regime. Namely, we use the recently re-evaluated MBH - Msph (Msph : spheroid absolute magnitude at 3.6 microm) scaling relation for spiral galaxies, the MBH - nsph (nsph : major axis Sersic index of the bulge) relation, the MBH - PA (PA: pitch angle) relation and the FP-BH for weakly accreting BHs, to independently estimate MBH in all seven galaxies. Results: We find that all LLAGN in our list have low-mass central black holes - with log MBH/Msol~6.5 on average - but they are, not IMBHs. All 4 methods used predicted consistent BH masses, in the 1sigma range. Furthermore, we report that, in contrast to previous classification, galaxy NGC 4470 is bulge-less, and cast doubts on the AGN classification of NGC 3507. Conclusions: We find that our latest, state-of-the-art techniques for bulge magnitude & Sersic index computations and the most recent updates of the MBH - Lsph, MBH - nsph , MBH - PA relations and the FP-BH produce consistent results in the low mass regime. We establish a multiple method approach for predicting BH masses in the regime where their spheres-of- grav. influence cannot be spatially resolved. Our approach mitigates against outliers from any one relation and provides a more robust average prediction. We will use our new method to revisit more IMBH candidates in LLAGN, Accepted by A&A: 14 pages, 4 figures, 2 tables

The ultra-faint dwarf galaxy Leo V has shown both photometric overdensities and kinematic members at large radii, along with a tentative kinematic gradient, suggesting that it may have undergone a close encounter with the Milky Way. We investigate these signs of disruption through a combination of i) high-precision photometry obtained with the Hubble Space Telescope (HST), ii) two epochs of stellar spectra obtained with the Hectochelle Spectrograph on the MMT, and iii) measurements from the Gaia mission. Using the HST data, we examine one of the reported stream-like overdensities at large radii, and conclude that it is not a true stellar stream, but instead a clump of foreground stars and background galaxies. Our spectroscopic analysis shows that one known member star is likely a binary, and challenges the membership status of three others, including two distant candidates that had formerly provided evidence for overall stellar mass loss. We also find evidence that the proposed kinematic gradient across Leo V might be due to small number statistics. We update the systemic proper motion of Leo V, finding $(\mu_\alpha \cos\delta, \mu_\delta)= (0.009\pm0.560$, $-0.777\pm0.314)$ mas yr$^{-1}$, which is consistent with its reported orbit that did not put Leo V at risk of being disturbed by the Milky Way. These findings remove most of the observational clues that suggested Leo V was disrupting, however, we also find new plausible member stars, two of which are located >5 half-light radii from the main body. These stars require further investigation. Therefore, the nature of Leo V still remains an open question., Comment: Higher resolution figures are available upon request. Submitted to the ApJ

We present a determination of the supermassive black hole (SMBH) mass function for early- and late-type galaxies in the nearby universe (z, Accepted for publication in ApJ. For full version of paper with high-resolution figures go to http://d.umn.edu/~msseigar/papers/MutluPakdil2016.pdf

Full list of authors: Drlica-Wagner, A.; Carlin, J. L.; Nidever, D. L.; Ferguson, P. S.; Kuropatkin, N.; Adamów, M.; Cerny, W.; Choi, Y.; Esteves, J. H.; Martínez-Vázquez, C. E.; Mau, S.; Miller, A. E.; Mutlu-Pakdil, B.; Neilsen, E. H.; Olsen, K. A. G.; Pace, A. B.; Riley, A. H.; Sakowska, J. D.; Sand, D. J.; Santana-Silva, L.; Tollerud, E. J.; Tucker, D. L.; Vivas, A. K.; Zaborowski, E.; Zenteno, A.; Abbott, T. M. C.; Allam, S.; Bechtol, K.; Bell, C. P. M.; Bell, E. F.; Bilaji, P.; Bom, C. R.; Carballo-Bello, J. A.; Crnojević, D.; Cioni, M. -R. L.; Diaz-Ocampo, A.; de Boer, T. J. L.; Erkal, D.; Gruendl, R. A.; Hernandez-Lang, D.; Hughes, A. K.; James, D. J.; Johnson, L. C.; Li, T. S.; Mao, Y. -Y.; Martínez-Delgado, D.; Massana, P.; McNanna, M.; Morgan, R.; Nadler, E. O.; Noël, N. E. D.; Palmese, A.; Peter, A. H. G.; Rykoff, E. S.; Sánchez, J.; Shipp, N.; Simon, J. D.; Smercina, A.; Soares-Santos, M.; Stringfellow, G. S.; Tavangar, K.; van der Marel, R. P.; Walker, A. R.; Wechsler, R. H.; Wu, J. F.; Yanny, B. s; Fitzpatrick, M.; Huang, L.; Jacques, A.; Nikutta, R.; Scott, A., The DECam Local Volume Exploration survey (DELVE) is a 126-night survey program on the 4 m Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile. DELVE seeks to understand the characteristics of faint satellite galaxies and other resolved stellar substructures over a range of environments in the Local Volume. DELVE will combine new DECam observations with archival DECam data to cover ∼15,000 deg2 of high Galactic latitude (|b| > 10°) southern sky to a 5σ depth of g, r, i, z ∼ 23.5 mag. In addition, DELVE will cover a region of ∼2200 deg2 around the Magellanic Clouds to a depth of g, r, i ∼ 24.5 mag and an area of ∼135 deg2 around four Magellanic analogs to a depth of g, i ∼ 25.5 mag. Here, we present an overview of the DELVE program and progress to date. We also summarize the first DELVE public data release (DELVE DR1), which provides point-source and automatic aperture photometry for ∼520 million astronomical sources covering ∼5000 deg2 of the southern sky to a 5σ point-source depth of g = 24.3 mag, r = 23.9 mag, i = 23.3 mag, and z = 22.8 mag. DELVE DR1 is publicly available via the NOIRLab Astro Data Lab science platform. © 2021. The American Astronomical Society. All rights reserved., The DELVE project is partially supported by Fermilab LDRD project L2019-011 and the NASA Fermi Guest Investigator Program Cycle 9 No. 91201. This work is supported by the Visiting Scholars Award Program of the Universities Research Association. A.B.P. acknowledges support from NSF grant AST-1813881. This research received support from the National Science Foundation (NSF) under grant No. NSF DGE-1656518 through the NSF Graduate Research Fellowship received by S.M. J.L.C. acknowledges support from NSF grant AST-1816196. J.D.S. acknowledges support from NSF grant AST-1714873. S.R.M. acknowledges support from NSF grant AST-1909497. D.J.S. acknowledges support from NSF grants AST-1821967 and AST-1813708. D.M.D. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Centre of Excellence Severo Ochoa" award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). C.P.M.B. and M.-R.L. C. acknowledge support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 682115). This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) Collaboration. Funding for the DES Projects has been provided by the DOE and NSF (USA), MISE (Spain), STFC (UK), HEFCE (UK), NCSA (UIUC), KICP (U. Chicago), CCAPP (Ohio State), MIFPA (Texas A&M University), CNPQ, FAPERJ, FINEP (Brazil), MINECO (Spain), DFG (Germany), and the collaborating institutions in the Dark Energy Survey, which are Argonne Lab, UC Santa Cruz, University of Cambridge, CIEMAT-Madrid, University of Chicago, University College London, DES-Brazil Consortium, University of Edinburgh, ETH Zurich, Fermilab, University of Illinois, ICE (IEEC-CSIC), IFAE Barcelona, Lawrence Berkeley Lab, LMU Munchen, and the associated Excellence Cluster Universe, University of Michigan, NSF's National Optical-Infrared Astronomy Research Laboratory, University of Nottingham, Ohio State University, OzDES Membership Consortium University of Pennsylvania, University of Portsmouth, SLAC National Lab, Stanford University, University of Sussex, and Texas A&M University. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC,https://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Based on observations at Cerro Tololo Inter-American Observatory, NSF's National Optical-Infrared Astronomy Research Laboratory (2019A-0305; PI: Drlica-Wagner), which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. This manuscript has been authored by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the US Department of Energy, Office of Science, Office of High Energy Physics. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government.