Star-forming knots and density wave in NGC 2997
Autor(a) principal: | |
---|---|
Data de Publicação: | 2006 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/98860 |
Resumo: | Context. Many grand design spiral galaxies show strings of bright knots along their arms on near-infrared K-band images. The alignment of such knots suggests a relation to the spiral pattern and possibly to a large-scale, star-forming front associated with a density wave. Aims. Bright knots in the southern arm of NGC 2997 were studied to determine their nature and evolutionary state. Methods. Low resolution near-infrared K- and J-band spectra of the knots were observed with ISAAC on the VLT. Results. Most of the knots show strong Hi Brγ emission with some also having He i and H2 emission. A few knots show indications of 12CO absorption. This suggests that the knots are very young stellar clusters with masses up to 5 × 104 Mʘ. Conclusions. The knots azimuthal distance from the K-band spiral correlates well with their Brγ strength, indicating that they are located inside the co-rotation of the density wave, which triggered them through a large-scale, star-forming front. These relative azimuthal distances suggest an age spread of more than 1.6Myr, which is incompatible with standard models for an instantaneous star burst. This indicates a more complex star-formation history, such as several bursts or continuous formation. |
id |
UFRGS-2_ce6938982c9f28ccca87fd00ae22742c |
---|---|
oai_identifier_str |
oai:www.lume.ufrgs.br:10183/98860 |
network_acronym_str |
UFRGS-2 |
network_name_str |
Repositório Institucional da UFRGS |
repository_id_str |
|
spelling |
Grosbol, PrebenDottori, Horacio AlbertoGredel, Roland2014-07-29T02:04:49Z20060004-6361http://hdl.handle.net/10183/98860000559751Context. Many grand design spiral galaxies show strings of bright knots along their arms on near-infrared K-band images. The alignment of such knots suggests a relation to the spiral pattern and possibly to a large-scale, star-forming front associated with a density wave. Aims. Bright knots in the southern arm of NGC 2997 were studied to determine their nature and evolutionary state. Methods. Low resolution near-infrared K- and J-band spectra of the knots were observed with ISAAC on the VLT. Results. Most of the knots show strong Hi Brγ emission with some also having He i and H2 emission. A few knots show indications of 12CO absorption. This suggests that the knots are very young stellar clusters with masses up to 5 × 104 Mʘ. Conclusions. The knots azimuthal distance from the K-band spiral correlates well with their Brγ strength, indicating that they are located inside the co-rotation of the density wave, which triggered them through a large-scale, star-forming front. These relative azimuthal distances suggest an age spread of more than 1.6Myr, which is incompatible with standard models for an instantaneous star burst. This indicates a more complex star-formation history, such as several bursts or continuous formation.application/pdfengAstronomy and astrophysics. Les Ulis. Vol. 453, no. 2 (July 2006), p. L25-L28Galaxias espiraisAglomerados estelaresGalaxies: individual: NGC 2997Galaxies: spiralGalaxies: star clustersGalaxies: structureInfrared: galaxiesTechniques: spectroscopicStar-forming knots and density wave in NGC 2997Estrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSORIGINAL000559751.pdf000559751.pdfTexto completo (inglês)application/pdf539520http://www.lume.ufrgs.br/bitstream/10183/98860/1/000559751.pdfadffcab1ca71e62fc26b19cfde044531MD51TEXT000559751.pdf.txt000559751.pdf.txtExtracted Texttext/plain17903http://www.lume.ufrgs.br/bitstream/10183/98860/2/000559751.pdf.txt4ab982255d42d794039abfc66216f92fMD52THUMBNAIL000559751.pdf.jpg000559751.pdf.jpgGenerated Thumbnailimage/jpeg2070http://www.lume.ufrgs.br/bitstream/10183/98860/3/000559751.pdf.jpgaf3b3e79d98adcc4d7aa780b746b1cf3MD5310183/988602018-10-22 07:53:27.707oai:www.lume.ufrgs.br:10183/98860Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-22T10:53:27Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Star-forming knots and density wave in NGC 2997 |
title |
Star-forming knots and density wave in NGC 2997 |
spellingShingle |
Star-forming knots and density wave in NGC 2997 Grosbol, Preben Galaxias espirais Aglomerados estelares Galaxies: individual: NGC 2997 Galaxies: spiral Galaxies: star clusters Galaxies: structure Infrared: galaxies Techniques: spectroscopic |
title_short |
Star-forming knots and density wave in NGC 2997 |
title_full |
Star-forming knots and density wave in NGC 2997 |
title_fullStr |
Star-forming knots and density wave in NGC 2997 |
title_full_unstemmed |
Star-forming knots and density wave in NGC 2997 |
title_sort |
Star-forming knots and density wave in NGC 2997 |
author |
Grosbol, Preben |
author_facet |
Grosbol, Preben Dottori, Horacio Alberto Gredel, Roland |
author_role |
author |
author2 |
Dottori, Horacio Alberto Gredel, Roland |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
Grosbol, Preben Dottori, Horacio Alberto Gredel, Roland |
dc.subject.por.fl_str_mv |
Galaxias espirais Aglomerados estelares |
topic |
Galaxias espirais Aglomerados estelares Galaxies: individual: NGC 2997 Galaxies: spiral Galaxies: star clusters Galaxies: structure Infrared: galaxies Techniques: spectroscopic |
dc.subject.eng.fl_str_mv |
Galaxies: individual: NGC 2997 Galaxies: spiral Galaxies: star clusters Galaxies: structure Infrared: galaxies Techniques: spectroscopic |
description |
Context. Many grand design spiral galaxies show strings of bright knots along their arms on near-infrared K-band images. The alignment of such knots suggests a relation to the spiral pattern and possibly to a large-scale, star-forming front associated with a density wave. Aims. Bright knots in the southern arm of NGC 2997 were studied to determine their nature and evolutionary state. Methods. Low resolution near-infrared K- and J-band spectra of the knots were observed with ISAAC on the VLT. Results. Most of the knots show strong Hi Brγ emission with some also having He i and H2 emission. A few knots show indications of 12CO absorption. This suggests that the knots are very young stellar clusters with masses up to 5 × 104 Mʘ. Conclusions. The knots azimuthal distance from the K-band spiral correlates well with their Brγ strength, indicating that they are located inside the co-rotation of the density wave, which triggered them through a large-scale, star-forming front. These relative azimuthal distances suggest an age spread of more than 1.6Myr, which is incompatible with standard models for an instantaneous star burst. This indicates a more complex star-formation history, such as several bursts or continuous formation. |
publishDate |
2006 |
dc.date.issued.fl_str_mv |
2006 |
dc.date.accessioned.fl_str_mv |
2014-07-29T02:04:49Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/98860 |
dc.identifier.issn.pt_BR.fl_str_mv |
0004-6361 |
dc.identifier.nrb.pt_BR.fl_str_mv |
000559751 |
identifier_str_mv |
0004-6361 000559751 |
url |
http://hdl.handle.net/10183/98860 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Astronomy and astrophysics. Les Ulis. Vol. 453, no. 2 (July 2006), p. L25-L28 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFRGS instname:Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS |
instname_str |
Universidade Federal do Rio Grande do Sul (UFRGS) |
instacron_str |
UFRGS |
institution |
UFRGS |
reponame_str |
Repositório Institucional da UFRGS |
collection |
Repositório Institucional da UFRGS |
bitstream.url.fl_str_mv |
http://www.lume.ufrgs.br/bitstream/10183/98860/1/000559751.pdf http://www.lume.ufrgs.br/bitstream/10183/98860/2/000559751.pdf.txt http://www.lume.ufrgs.br/bitstream/10183/98860/3/000559751.pdf.jpg |
bitstream.checksum.fl_str_mv |
adffcab1ca71e62fc26b19cfde044531 4ab982255d42d794039abfc66216f92f af3b3e79d98adcc4d7aa780b746b1cf3 |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 MD5 |
repository.name.fl_str_mv |
Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS) |
repository.mail.fl_str_mv |
|
_version_ |
1801224842572201984 |