First confirmed ultra-compact dwarf galaxy in the NGC 5044 group

Autores
Faifer, Favio Raúl; Escudero, Carlos Gabriel; Scalia, María C.; Smith Castelli, Analía Viviana; Norris, Mark; De Rossi, María E.; Forte, Juan Carlos; Cellone, Sergio Aldo
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Context. Ultra-compact dwarfs (UCDs) are stellar systems displaying colours and metallicities between those of globular clusters (GCs) and early-type dwarf galaxies, as well as sizes of Reff 100 pc and luminosities in the range-13.5 < MV<-11 mag. Although their origin is still subject of debate, the most popular scenarios suggest that they are massive star clusters or the nuclei of tidally stripped dwarf galaxies. Aims. NGC 5044 is the central massive elliptical galaxy of the NGC 5044 group. Its GC/UCD system is completely unexplored. Methods. In Gemini+GMOS deep images of several fields around NGC 5044 and in spectroscopic multi-object data of one of these fields, we detected an unresolved source with g′ ∼ 20.6 mag, compatible with being an UCD. Its radial velocity was obtained with FXCOR and the penalized pixel-fitting (pPXF) code. To study its stellar population content, we measured the Lick/IDS indices and compared them with predictions of single stellar population models, and we used the full spectral fitting technique. Results. The spectroscopic analysis of the UCD revealed a radial velocity that agrees with the velocity of the elliptical galaxy NGC 5044. From the Lick/IDS indices, we have obtained a luminosity-weighted age and metallicity of 11.7+ 1.4 -1.2 Gyr and [Z/H] =-0.79 ± 0.04 dex, respectively, as well as [α/Fe] = 0.30 ± 0.06. From the full spectral fitting technique, we measured a lower age (8.52 Gyr) and a similar total metallicity ([Z/H] =-0.86 dex). Conclusions. Our results indicate that NGC 5044-UCD1 is most likely an extreme GC (MV ∼-12.5 mag) belonging to the GC system of the elliptical galaxy NGC 5044.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
Materia
Ciencias Astronómicas
Galaxies: elliptical and lenticular, cD
Galaxies: photometry
Galaxies: star clusters: general
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/87115

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/87115
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling First confirmed ultra-compact dwarf galaxy in the NGC 5044 groupFaifer, Favio RaúlEscudero, Carlos GabrielScalia, María C.Smith Castelli, Analía VivianaNorris, MarkDe Rossi, María E.Forte, Juan CarlosCellone, Sergio AldoCiencias AstronómicasGalaxies: elliptical and lenticular, cDGalaxies: photometryGalaxies: star clusters: generalContext. Ultra-compact dwarfs (UCDs) are stellar systems displaying colours and metallicities between those of globular clusters (GCs) and early-type dwarf galaxies, as well as sizes of Reff 100 pc and luminosities in the range-13.5 < MV<-11 mag. Although their origin is still subject of debate, the most popular scenarios suggest that they are massive star clusters or the nuclei of tidally stripped dwarf galaxies. Aims. NGC 5044 is the central massive elliptical galaxy of the NGC 5044 group. Its GC/UCD system is completely unexplored. Methods. In Gemini+GMOS deep images of several fields around NGC 5044 and in spectroscopic multi-object data of one of these fields, we detected an unresolved source with g′ ∼ 20.6 mag, compatible with being an UCD. Its radial velocity was obtained with FXCOR and the penalized pixel-fitting (pPXF) code. To study its stellar population content, we measured the Lick/IDS indices and compared them with predictions of single stellar population models, and we used the full spectral fitting technique. Results. The spectroscopic analysis of the UCD revealed a radial velocity that agrees with the velocity of the elliptical galaxy NGC 5044. From the Lick/IDS indices, we have obtained a luminosity-weighted age and metallicity of 11.7+ 1.4 -1.2 Gyr and [Z/H] =-0.79 ± 0.04 dex, respectively, as well as [α/Fe] = 0.30 ± 0.06. From the full spectral fitting technique, we measured a lower age (8.52 Gyr) and a similar total metallicity ([Z/H] =-0.86 dex). Conclusions. Our results indicate that NGC 5044-UCD1 is most likely an extreme GC (MV ∼-12.5 mag) belonging to the GC system of the elliptical galaxy NGC 5044.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plata2017info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttp://sedici.unlp.edu.ar/handle/10915/87115enginfo:eu-repo/semantics/altIdentifier/issn/0004-6361info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201730493info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:17:14Zoai:sedici.unlp.edu.ar:10915/87115Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:17:15.248SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
title First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
spellingShingle First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
Faifer, Favio Raúl
Ciencias Astronómicas
Galaxies: elliptical and lenticular, cD
Galaxies: photometry
Galaxies: star clusters: general
title_short First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
title_full First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
title_fullStr First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
title_full_unstemmed First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
title_sort First confirmed ultra-compact dwarf galaxy in the NGC 5044 group
dc.creator.none.fl_str_mv Faifer, Favio Raúl
Escudero, Carlos Gabriel
Scalia, María C.
Smith Castelli, Analía Viviana
Norris, Mark
De Rossi, María E.
Forte, Juan Carlos
Cellone, Sergio Aldo
author Faifer, Favio Raúl
author_facet Faifer, Favio Raúl
Escudero, Carlos Gabriel
Scalia, María C.
Smith Castelli, Analía Viviana
Norris, Mark
De Rossi, María E.
Forte, Juan Carlos
Cellone, Sergio Aldo
author_role author
author2 Escudero, Carlos Gabriel
Scalia, María C.
Smith Castelli, Analía Viviana
Norris, Mark
De Rossi, María E.
Forte, Juan Carlos
Cellone, Sergio Aldo
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Ciencias Astronómicas
Galaxies: elliptical and lenticular, cD
Galaxies: photometry
Galaxies: star clusters: general
topic Ciencias Astronómicas
Galaxies: elliptical and lenticular, cD
Galaxies: photometry
Galaxies: star clusters: general
dc.description.none.fl_txt_mv Context. Ultra-compact dwarfs (UCDs) are stellar systems displaying colours and metallicities between those of globular clusters (GCs) and early-type dwarf galaxies, as well as sizes of Reff 100 pc and luminosities in the range-13.5 < MV<-11 mag. Although their origin is still subject of debate, the most popular scenarios suggest that they are massive star clusters or the nuclei of tidally stripped dwarf galaxies. Aims. NGC 5044 is the central massive elliptical galaxy of the NGC 5044 group. Its GC/UCD system is completely unexplored. Methods. In Gemini+GMOS deep images of several fields around NGC 5044 and in spectroscopic multi-object data of one of these fields, we detected an unresolved source with g′ ∼ 20.6 mag, compatible with being an UCD. Its radial velocity was obtained with FXCOR and the penalized pixel-fitting (pPXF) code. To study its stellar population content, we measured the Lick/IDS indices and compared them with predictions of single stellar population models, and we used the full spectral fitting technique. Results. The spectroscopic analysis of the UCD revealed a radial velocity that agrees with the velocity of the elliptical galaxy NGC 5044. From the Lick/IDS indices, we have obtained a luminosity-weighted age and metallicity of 11.7+ 1.4 -1.2 Gyr and [Z/H] =-0.79 ± 0.04 dex, respectively, as well as [α/Fe] = 0.30 ± 0.06. From the full spectral fitting technique, we measured a lower age (8.52 Gyr) and a similar total metallicity ([Z/H] =-0.86 dex). Conclusions. Our results indicate that NGC 5044-UCD1 is most likely an extreme GC (MV ∼-12.5 mag) belonging to the GC system of the elliptical galaxy NGC 5044.
Facultad de Ciencias Astronómicas y Geofísicas
Instituto de Astrofísica de La Plata
description Context. Ultra-compact dwarfs (UCDs) are stellar systems displaying colours and metallicities between those of globular clusters (GCs) and early-type dwarf galaxies, as well as sizes of Reff 100 pc and luminosities in the range-13.5 < MV<-11 mag. Although their origin is still subject of debate, the most popular scenarios suggest that they are massive star clusters or the nuclei of tidally stripped dwarf galaxies. Aims. NGC 5044 is the central massive elliptical galaxy of the NGC 5044 group. Its GC/UCD system is completely unexplored. Methods. In Gemini+GMOS deep images of several fields around NGC 5044 and in spectroscopic multi-object data of one of these fields, we detected an unresolved source with g′ ∼ 20.6 mag, compatible with being an UCD. Its radial velocity was obtained with FXCOR and the penalized pixel-fitting (pPXF) code. To study its stellar population content, we measured the Lick/IDS indices and compared them with predictions of single stellar population models, and we used the full spectral fitting technique. Results. The spectroscopic analysis of the UCD revealed a radial velocity that agrees with the velocity of the elliptical galaxy NGC 5044. From the Lick/IDS indices, we have obtained a luminosity-weighted age and metallicity of 11.7+ 1.4 -1.2 Gyr and [Z/H] =-0.79 ± 0.04 dex, respectively, as well as [α/Fe] = 0.30 ± 0.06. From the full spectral fitting technique, we measured a lower age (8.52 Gyr) and a similar total metallicity ([Z/H] =-0.86 dex). Conclusions. Our results indicate that NGC 5044-UCD1 is most likely an extreme GC (MV ∼-12.5 mag) belonging to the GC system of the elliptical galaxy NGC 5044.
publishDate 2017
dc.date.none.fl_str_mv 2017
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/87115
url http://sedici.unlp.edu.ar/handle/10915/87115
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dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0004-6361
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201730493
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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