Pegasus IV: Discovery and Spectroscopic Confirmation of an Ultra-faint Dwarf Galaxy in the Constellation Pegasus
Pegasus IV: descubrimiento y confirmación espectroscópica de una galaxia enana ultradébil en la constelación de Pegasus
dc.contributor | williamcerny@uchicago.edu | |
dc.contributor | Fermilab LDRD project [L2019-011]; NASA Fermi Guest Investigator Program Cycle 9 [91201]; University of Chicago Quad Undergraduate Research Scholars program; Carnegie Astrophysics Summer Student Internship (CASSI) program; NSF [NSF DGE-1656518]; international Gemini Observatory; National Science Foundation; NSF Astronomy and Astrophysics Postdoctoral Fellowship [1220083]; KICP (U. Chicago); National Science Foundation (NSF) [DE-AC02-07CH11359]; NSF's NOIRLab; ANID FONDECYT Regular [2019A-0305]; ANID BASAL project; NSF (USA); DOE; Dark Energy Survey; MISE (Spain); Argonne Lab; STFC (UK); UC Santa Cruz; HEFCE (UK); University of Cambridge; NCSA (UIUC); CIEMAT-Madrid; CCAPP (Ohio State); University of Chicago; MIFPA (Texas AM University); University College London; CNPQ; DES-Brazil Consortium; FAPERJ; University of Edinburgh; FINEP (Brazil); ETH Zuerich; MINECO (Spain); Fermilab; DFG (Germany); University of Illinois; Fermilab, University of Illinois, ICE [DE-AC02-07CH11359, AST-1813881]; ICE (IEEC-CSIC); US Department of Energy, Office of Science, Office of High Energy Physics; IFAE Barcelona; Gemini Observatory; Lawrence Berkeley Lab; LMU Muenchen; associated Excellence Cluster Universe; University of Michigan [FB210003]; 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; Texas AM University; [AST-2001663] | |
dc.contributor | Riley, Alex https://orcid.org/0000-0001-5805-5766 | |
dc.contributor | Simon, Joshua https://orcid.org/0000-0002-4733-4994 | |
dc.contributor | Martinez Vazquez, Clara Eugenia https://orcid.org/0000-0002-9144-7726 | |
dc.contributor | Li, Ting https://orcid.org/0000-0002-9110-6163 | |
dc.contributor | Sakowska, Joanna https://orcid.org/0000-0002-1594-1466 | |
dc.contributor | Pace, Andrew https://orcid.org/0000-0002-6021-8760 | |
dc.creator | Cerny, W. | |
dc.creator | Simon, J. D. | |
dc.creator | Li, T. S. | |
dc.creator | Drlica-Wagner, A. | |
dc.creator | Pace, A. B. | |
dc.creator | Martinez-Vazquez, C. E. | |
dc.creator | Riley, A. H. | |
dc.creator | Mutlu-Pakdil, B. | |
dc.creator | Mau, S. | |
dc.creator | Ferguson, P. S. | |
dc.creator | Erkal, D. | |
dc.creator | Munoz, R. R. | |
dc.creator | Bom, C. R. | |
dc.creator | Carlin, J. L. | |
dc.creator | Carollo, D. | |
dc.creator | Choi, Y. | |
dc.creator | Ji, A. P. | |
dc.creator | Manwadkar, V. | |
dc.creator | Martinez-Delgado, D. | |
dc.creator | Miller, A. E. | |
dc.creator | Noel, N. E. D. | |
dc.creator | Sakowska, J. D. | |
dc.creator | Sand, D. J. | |
dc.creator | Stringfellow, G. S. | |
dc.creator | Tollerud, E. J. | |
dc.creator | Vivas, A. K. | |
dc.creator | Carballo-Bello, J. A. | |
dc.creator | Hernandez-Lang, D. | |
dc.creator | James, D. J. | |
dc.creator | Nidever, D. L. | |
dc.creator | Castellon, J. L. Nilo | |
dc.creator | Olsen, K. A. G. | |
dc.creator | Zenteno, A. | |
dc.date | 2023-04-18T01:55:33Z | |
dc.date | 2023-04-18T01:55:33Z | |
dc.date | 2023 | |
dc.date.accessioned | 2023-09-27T20:20:16Z | |
dc.date.available | 2023-09-27T20:20:16Z | |
dc.identifier | 0004-637X | |
dc.identifier | https://repositorio.uta.cl/xmlui/handle/20.500.14396/2802 | |
dc.identifier | 1538-4357 | |
dc.identifier | 10.3847/1538-4357/aca1c3 | |
dc.identifier | 8E3HG | |
dc.identifier | WOS:000918868200001 | |
dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/8943456 | |
dc.description | We report the discovery of Pegasus IV, an ultra-faint dwarf galaxy found in archival data from the Dark Energy Camera processed by the DECam Local Volume Exploration Survey. Pegasus IV is a compact, ultra-faint stellar system ( = -r(1/2) 41(-6)(+8) pc; M-V = -4.25 +/- 0.2 mag) located at a heliocentric distance of 90(-6)(+4) kpc. Based on spectra of seven nonvariable member stars observed with Magellan/IMACS, we confidently resolve Pegasus IV's velocity dispersion, measuring s = sigma(v) 3.3(-1.1)(+1.7) km s(-1) (after excluding three velocity outliers); this implies a mass-to-light ratio of M1/2LV ,(1/2)=167(-99)(+224) M-?/L-? for the system. From the five stars with the highest signal-to-noise spectra, we also measure a systemic metallicity of [Fe/H] = -2.63(-0.30)(+0.26) dex, making Pegasus IV one of the most metal-poor ultra-faint dwarfs. We tentatively resolve a nonzero metallicity dispersion for the system. These measurements provide strong evidence that Pegasus IV is a dark-matter-dominated dwarf galaxy, rather than a star cluster. We measure Pegasus IV's proper motion using data from Gaia Early Data Release 3, finding (mu(alpha*, mu delta)) = (0.33 +/- 0.07, -0.21 +/- 0.08) mas yr(-1). When combined with our measured systemic velocity, this proper motion suggests that Pegasus IV is on an elliptical, retrograde orbit, and is currently near its orbital apocenter. Lastly, we identify three potential RR Lyrae variable stars within Pegasus IV, including one candidate member located more than 10 half-light radii away from the system's centroid. The discovery of yet another ultra-faint dwarf galaxy strongly suggests that the census of Milky Way satellites is still incomplete, even within 100 kpc. | |
dc.description | Reportamos el descubrimiento de Pegasus IV, una galaxia enana ultra-débil que se encuentra en los datos de archivo de la Cámara de Energía Oscura procesada por la Encuesta de Exploración de Volumen Local DECam. Pegasus IV es un sistema estelar compacto y ultradébil ( = -r(1/2) 41(-6)(+8) pc; MV = -4,25 +/- 0,2 mag) ubicado a una distancia heliocéntrica de 90(- 6)(+4) kpc. Con base en los espectros de siete estrellas miembro no variables observadas con Magellan/IMACS, resolvemos con confianza la dispersión de velocidad de Pegasus IV, midiendo s = sigma(v) 3.3(-1.1)(+1.7) km s(-1) (después de excluir tres valores atípicos de velocidad ); esto implica una relación masa-luz de M1/2LV ,(1/2)=167(-99)(+224) M-?/L-? para el sistema De las cinco estrellas con los espectros de señal a ruido más altos, también medimos una metalicidad sistémica de [Fe/H] = -2.63(-0.30)(+0.26) dex, lo que convierte a Pegasus IV en uno de los ultra-pobres en metales. -débiles enanos. Resolvemos tentativamente una dispersión de metalicidad distinta de cero para el sistema. Estas mediciones proporcionan una fuerte evidencia de que Pegasus IV es una galaxia enana dominada por materia oscura, en lugar de un cúmulo estelar. Medimos el movimiento propio de Pegasus IV usando datos de Gaia Early Data Release 3, encontrando (mu(alpha*, mu delta)) = (0.33 +/- 0.07, -0.21 +/- 0.08) mas año(-1). Cuando se combina con nuestra velocidad sistémica medida, este movimiento propio sugiere que Pegasus IV está en una órbita retrógrada elíptica, y actualmente está cerca de su apocentro orbital. Por último, identificamos tres posibles estrellas variables RR Lyrae dentro de Pegasus IV, incluido un miembro candidato ubicado a más de 10 radios de media luz del centroide del sistema. El descubrimiento de otra galaxia enana ultradébil sugiere fuertemente que el censo de satélites de la Vía Láctea aún está incompleto, incluso dentro de los 100 kpc. | |
dc.format | application/pdf | |
dc.format | 18 páginas | |
dc.language | English | |
dc.publisher | IOP Publishing Ltd | |
dc.relation | Astrophysical Journal, vol.942 no.2 (2023) | |
dc.relation | https://doi.org/10.3847/1538-4357/aca1c3 | |
dc.rights | Green Published, Green Submitted, gold | |
dc.rights | Acceso abierto | |
dc.source | Astrophysical Journal | |
dc.subject | Milky-Way Satellite | |
dc.subject | Rr Lyrae Stars | |
dc.subject | Large-Magellanic-Cloud | |
dc.subject | Exploring Halo Substructure | |
dc.subject | Dark-Matter Annihilation | |
dc.subject | Metal-Poor Stars | |
dc.subject | Proper Motions | |
dc.subject | Globular-Clusters | |
dc.subject | Mass-Distribution | |
dc.subject | Giant Stars | |
dc.subject | Satélite de la Vía Láctea | |
dc.subject | Estrellas Rr Lyrae | |
dc.subject | Gran Nube de Magallanes | |
dc.subject | Exploración de la Subestructura del Halo | |
dc.subject | Aniquilación de Materia Oscura | |
dc.subject | Estrellas Pobres En Metal | |
dc.subject | Movimientos Propios | |
dc.subject | Cúmulos Globulares | |
dc.subject | Distribución de Masas | |
dc.subject | Estrellas Gigantes. | |
dc.title | Pegasus IV: Discovery and Spectroscopic Confirmation of an Ultra-faint Dwarf Galaxy in the Constellation Pegasus | |
dc.title | Pegasus IV: descubrimiento y confirmación espectroscópica de una galaxia enana ultradébil en la constelación de Pegasus | |
dc.type | Artículo de revista |