Spiral structure of the third galactic quadrant and the solution to the Canis Major debate

Autores
Moitinho, A.; Vázquez, Rubén Ángel; Carraro, G.; Baume, Gustavo; Giorgi, Edgard Ervar Salvador; Lyra, W.
Año de publicación
2006
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
With the discoveryofthe Sagittarius dwarf spheroidal, agalaxy caughtinthe processofmerging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The identification of a stellar ring-like structure in Monoceros, spanning more than 100°, and the detection of an overdensity of stars in the direction of the constellation of Canis Major (CMa), apparently associated to the ring, has led to the widespread belief that a second galaxy being cannibalized by the Milky Way had been found. In this scenario, the overdensity would be the remaining core of the disrupted galaxy and the ring would be the tidal debris left behind. However, unlike the Sagittarius dwarf, which is well below the Galactic plane and whose orbit, and thus tidal tail, is nearly perpendicular to the plane of the Milky Way, the putative CMa galaxy and ring are nearly co-planar with the Galactic disc. This severely complicates the interpretation of observations. In this Letter, we show that our new description of the Milky Way leads to a completely different picture. We argue that the Norma-Cygnus spiral arm defines a distant stellar ring crossing Monoceros and the overdensity is simply a projection effect of looking along the nearby local arm. Our perspective sheds new light on a very poorly known region, the third Galactic quadrant, where CMa is located.
Facultad de Ciencias Astronómicas y Geofísicas
Materia
Astronomía
Galaxies: dwarf
Galaxy: stellar content
Galaxy: structure
Open clusters and associations: 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:10915/83271

id SEDICI_98ff2b379455654d18ee9d0c22e37460
oai_identifier_str oai:sedici.unlp.edu.ar:10915/83271
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Spiral structure of the third galactic quadrant and the solution to the Canis Major debateMoitinho, A.Vázquez, Rubén ÁngelCarraro, G.Baume, GustavoGiorgi, Edgard Ervar SalvadorLyra, W.AstronomíaGalaxies: dwarfGalaxy: stellar contentGalaxy: structureOpen clusters and associations: generalWith the discoveryofthe Sagittarius dwarf spheroidal, agalaxy caughtinthe processofmerging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The identification of a stellar ring-like structure in Monoceros, spanning more than 100°, and the detection of an overdensity of stars in the direction of the constellation of Canis Major (CMa), apparently associated to the ring, has led to the widespread belief that a second galaxy being cannibalized by the Milky Way had been found. In this scenario, the overdensity would be the remaining core of the disrupted galaxy and the ring would be the tidal debris left behind. However, unlike the Sagittarius dwarf, which is well below the Galactic plane and whose orbit, and thus tidal tail, is nearly perpendicular to the plane of the Milky Way, the putative CMa galaxy and ring are nearly co-planar with the Galactic disc. This severely complicates the interpretation of observations. In this Letter, we show that our new description of the Milky Way leads to a completely different picture. We argue that the Norma-Cygnus spiral arm defines a distant stellar ring crossing Monoceros and the overdensity is simply a projection effect of looking along the nearby local arm. Our perspective sheds new light on a very poorly known region, the third Galactic quadrant, where CMa is located.Facultad de Ciencias Astronómicas y Geofísicas2006info: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/10915/83271enginfo:eu-repo/semantics/altIdentifier/issn/1745-3933info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1745-3933.2006.00163.xinfo: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:UNLP2025-09-29T11:15:46Zoai:sedici.unlp.edu.ar:10915/83271Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:15:46.854SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
title Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
spellingShingle Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
Moitinho, A.
Astronomía
Galaxies: dwarf
Galaxy: stellar content
Galaxy: structure
Open clusters and associations: general
title_short Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
title_full Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
title_fullStr Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
title_full_unstemmed Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
title_sort Spiral structure of the third galactic quadrant and the solution to the Canis Major debate
dc.creator.none.fl_str_mv Moitinho, A.
Vázquez, Rubén Ángel
Carraro, G.
Baume, Gustavo
Giorgi, Edgard Ervar Salvador
Lyra, W.
author Moitinho, A.
author_facet Moitinho, A.
Vázquez, Rubén Ángel
Carraro, G.
Baume, Gustavo
Giorgi, Edgard Ervar Salvador
Lyra, W.
author_role author
author2 Vázquez, Rubén Ángel
Carraro, G.
Baume, Gustavo
Giorgi, Edgard Ervar Salvador
Lyra, W.
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Astronomía
Galaxies: dwarf
Galaxy: stellar content
Galaxy: structure
Open clusters and associations: general
topic Astronomía
Galaxies: dwarf
Galaxy: stellar content
Galaxy: structure
Open clusters and associations: general
dc.description.none.fl_txt_mv With the discoveryofthe Sagittarius dwarf spheroidal, agalaxy caughtinthe processofmerging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The identification of a stellar ring-like structure in Monoceros, spanning more than 100°, and the detection of an overdensity of stars in the direction of the constellation of Canis Major (CMa), apparently associated to the ring, has led to the widespread belief that a second galaxy being cannibalized by the Milky Way had been found. In this scenario, the overdensity would be the remaining core of the disrupted galaxy and the ring would be the tidal debris left behind. However, unlike the Sagittarius dwarf, which is well below the Galactic plane and whose orbit, and thus tidal tail, is nearly perpendicular to the plane of the Milky Way, the putative CMa galaxy and ring are nearly co-planar with the Galactic disc. This severely complicates the interpretation of observations. In this Letter, we show that our new description of the Milky Way leads to a completely different picture. We argue that the Norma-Cygnus spiral arm defines a distant stellar ring crossing Monoceros and the overdensity is simply a projection effect of looking along the nearby local arm. Our perspective sheds new light on a very poorly known region, the third Galactic quadrant, where CMa is located.
Facultad de Ciencias Astronómicas y Geofísicas
description With the discoveryofthe Sagittarius dwarf spheroidal, agalaxy caughtinthe processofmerging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The identification of a stellar ring-like structure in Monoceros, spanning more than 100°, and the detection of an overdensity of stars in the direction of the constellation of Canis Major (CMa), apparently associated to the ring, has led to the widespread belief that a second galaxy being cannibalized by the Milky Way had been found. In this scenario, the overdensity would be the remaining core of the disrupted galaxy and the ring would be the tidal debris left behind. However, unlike the Sagittarius dwarf, which is well below the Galactic plane and whose orbit, and thus tidal tail, is nearly perpendicular to the plane of the Milky Way, the putative CMa galaxy and ring are nearly co-planar with the Galactic disc. This severely complicates the interpretation of observations. In this Letter, we show that our new description of the Milky Way leads to a completely different picture. We argue that the Norma-Cygnus spiral arm defines a distant stellar ring crossing Monoceros and the overdensity is simply a projection effect of looking along the nearby local arm. Our perspective sheds new light on a very poorly known region, the third Galactic quadrant, where CMa is located.
publishDate 2006
dc.date.none.fl_str_mv 2006
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/10915/83271
url http://sedici.unlp.edu.ar/handle/10915/83271
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1745-3933
info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1745-3933.2006.00163.x
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)
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
_version_ 1844616030152818688
score 13.070432