The Astrophysical Journal (Jan 2023)
Six More Ultra-faint Milky Way Companions Discovered in the DECam Local Volume Exploration Survey
- W. Cerny,
- C. E. Martínez-Vázquez,
- A. Drlica-Wagner,
- A. B. Pace,
- B. Mutlu-Pakdil,
- T. S. Li,
- A. H. Riley,
- D. Crnojević,
- C. R. Bom,
- J. A. Carballo-Bello,
- J. L. Carlin,
- A. Chiti,
- Y. Choi,
- M. L. M. Collins,
- E Darragh-Ford,
- P. S. Ferguson,
- M. Geha,
- D. Martínez-Delgado,
- P. Massana,
- S. Mau,
- G. E. Medina,
- R. R. Muñoz,
- E. O. Nadler,
- N. E. D. Noël,
- K. A. G. Olsen,
- A. Pieres,
- J. D. Sakowska,
- J. D. Simon,
- G. S. Stringfellow,
- E. J. Tollerud,
- A. K. Vivas,
- A. R. Walker,
- R. H. Wechsler,
- DELVE Collaboration
Affiliations
- W. Cerny
- ORCiD
- Kavli Institute for Cosmological Physics, University of Chicago , Chicago, IL 60637, USA ; [email protected]; Department of Astronomy and Astrophysics, University of Chicago , Chicago IL 60637, USA; Department of Astronomy, Yale University , New Haven, CT 06520, USA
- C. E. Martínez-Vázquez
- ORCiD
- Gemini Observatory , NSF’s NOIRLab, 670 N. A’ohoku Place, Hilo, HI 96720, USA
- A. Drlica-Wagner
- ORCiD
- Kavli Institute for Cosmological Physics, University of Chicago , Chicago, IL 60637, USA ; [email protected]; Department of Astronomy and Astrophysics, University of Chicago , Chicago IL 60637, USA; Fermi National Accelerator Laboratory , P.O. Box 500, Batavia, IL 60510, USA
- A. B. Pace
- ORCiD
- McWilliams Center for Cosmology, Carnegie Mellon University , 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
- B. Mutlu-Pakdil
- ORCiD
- Department of Physics and Astronomy, Dartmouth College , Hanover, NH 03755, USA
- T. S. Li
- ORCiD
- Department of Astronomy and Astrophysics, University of Toronto , 50 St. George Street, Toronto ON, M5S 3H4, Canada
- A. H. Riley
- ORCiD
- Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE, UK; George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University , College Station, TX 77843, USA; Department of Physics and Astronomy, Texas A&M University , College Station, TX 77843, USA
- D. Crnojević
- ORCiD
- Department of Chemistry and Physics, University of Tampa , 401 West Kennedy Boulevard, Tampa, FL 33606, USA
- C. R. Bom
- ORCiD
- Centro Brasileiro de Pesquisas Físicas , Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ, Brazil
- J. A. Carballo-Bello
- ORCiD
- Instituto de Alta Investigación, Sede Esmeralda, Universidad de Tarapacá , Av. Luis Emilio Recabarren 2477, Iquique, Chile
- J. L. Carlin
- ORCiD
- Rubin Observatory/AURA, 950 North Cherry Avenue , Tucson, AZ 85719, USA
- A. Chiti
- ORCiD
- Kavli Institute for Cosmological Physics, University of Chicago , Chicago, IL 60637, USA ; [email protected]; Department of Astronomy and Astrophysics, University of Chicago , Chicago IL 60637, USA
- Y. Choi
- ORCiD
- Department of Astronomy, University of California , Berkeley, Berkeley, CA 94720, USA
- M. L. M. Collins
- ORCiD
- Department of Physics, University of Surrey , Guildford GU2 7XH, UK
- E Darragh-Ford
- ORCiD
- Department of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA; Kavli Institute for Particle Astrophysics & Cosmology, P.O. Box 2450, Stanford University , Stanford, CA 94305, USA; SLAC National Accelerator Laboratory , Menlo Park, CA 94025, USA
- P. S. Ferguson
- ORCiD
- Department of Physics, University of Wisconsin-Madison , Madison, WI 53706, USA
- M. Geha
- ORCiD
- Department of Astronomy, Yale University , New Haven, CT 06520, USA
- D. Martínez-Delgado
- ORCiD
- Instituto de Astrofísica de Andalucía , CSIC, E-18080 Granada, Spain
- P. Massana
- ORCiD
- Department of Physics, Montana State University , P.O. Box 173840, Bozeman, MT 59717-3840, USA
- S. Mau
- ORCiD
- Department of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA; Kavli Institute for Particle Astrophysics & Cosmology, P.O. Box 2450, Stanford University , Stanford, CA 94305, USA
- G. E. Medina
- ORCiD
- Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg , Mönchhofstr. 12-14, D-69120 Heidelberg, Germany
- R. R. Muñoz
- ORCiD
- Departamento de Astronomía, Universidad de Chile , Camino El Observatorio 1515, Las Condes, Santiago, Chile
- E. O. Nadler
- ORCiD
- Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA; Department of Physics & Astronomy, University of Southern California , Los Angeles, CA 90007, USA
- N. E. D. Noël
- ORCiD
- Department of Physics, University of Surrey , Guildford GU2 7XH, UK
- K. A. G. Olsen
- ORCiD
- NSF’s National Optical-Infrared Astronomy Research Laboratory , 950 N. Cherry Avenue, Tucson, AZ 85719, USA
- A. Pieres
- ORCiD
- Laboratório Interinstitucional de e-Astronomia—LIneA , Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400, Brazil; Observatório Nacional , Rua Gal. José Cristino 77, Rio de Janeiro, RJ—20921-400, Brazil
- J. D. Sakowska
- ORCiD
- Department of Physics, University of Surrey , Guildford GU2 7XH, UK
- J. D. Simon
- ORCiD
- Observatories of the Carnegie Institution for Science , 813 Santa Barbara Street, Pasadena, CA 91101, USA
- G. S. Stringfellow
- ORCiD
- Center for Astrophysics and Space Astronomy, University of Colorado , 389 UCB, Boulder, CO 80309-0389, USA
- E. J. Tollerud
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA
- A. K. Vivas
- ORCiD
- Cerro Tololo Inter-American Observatory, NSF’s National Optical-Infrared Astronomy Research Laboratory , Casilla 603, La Serena, Chile
- A. R. Walker
- ORCiD
- Cerro Tololo Inter-American Observatory, NSF’s National Optical-Infrared Astronomy Research Laboratory , Casilla 603, La Serena, Chile
- R. H. Wechsler
- ORCiD
- Department of Physics, Stanford University , 382 Via Pueblo Mall, Stanford, CA 94305, USA; Kavli Institute for Particle Astrophysics & Cosmology, P.O. Box 2450, Stanford University , Stanford, CA 94305, USA; SLAC National Accelerator Laboratory , Menlo Park, CA 94025, USA
- DELVE Collaboration
- DOI
- https://doi.org/10.3847/1538-4357/acdd78
- Journal volume & issue
-
Vol. 953,
no. 1
p. 1
Abstract
We report the discovery of six ultra-faint Milky Way satellites identified 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 ≥ −3.2 mag) and old, metal-poor stellar populations ( τ > 10 Gyr, [Fe/H] 15 pc), while the other three are compact ( r _1/2 < 10 pc). From these properties, we infer that the former three systems (Boötes 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 Boötes 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.
Keywords
