Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291

NGC 5291 is an early type galaxy at the edge of the cluster Abell 3574 which drew the attention because of the unusual high amount of atomic gas (∼ 5 × 10110 M·) found associated to it. The HI is distributed along a huge and fragmented ring, possibly formed after a tidal interaction with a companion...

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Detalles Bibliográficos
Autores principales: Duc, P.-A., Mirabel, I.F.
Formato: JOUR
Materias:
Galaxies: dwarf
Galaxies: formation
Galaxies: individual: NGC 5291
Galaxies: interactions
Galaxies: ISM
Radio lines: galaxies
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00046361_v333_n3_p813_Duc
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_00046361_v333_n3_p813_Duc
record_format dspace
spelling todo:paper_00046361_v333_n3_p813_Duc2023-10-03T13:59:51Z Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291 Duc, P.-A. Mirabel, I.F. Galaxies: dwarf Galaxies: formation Galaxies: individual: NGC 5291 Galaxies: interactions Galaxies: ISM Radio lines: galaxies NGC 5291 is an early type galaxy at the edge of the cluster Abell 3574 which drew the attention because of the unusual high amount of atomic gas (∼ 5 × 10110 M·) found associated to it. The HI is distributed along a huge and fragmented ring, possibly formed after a tidal interaction with a companion galaxy. We present multi-slit optical spectroscopic observations and optical/near-infrared images of the system. We show that NGC 5291 is a LINER galaxy exhibiting several remnants of previous merging events, in particular a curved dust lane and a counter-rotation of the gas with respect to the stars. The atomic hydrogen has undoubtly an external origin and was probably accreted by the galaxy from a gas-rich object in the cluster. It is unlikely that the HI comes from the closest companion of NGC 5291, the so-called "Seashell" galaxy, which appears to be a fly-by object at a velocity greater than 400 km s-1. We have analyzed the properties of 11 optical counterparts to the clumps observed in the HI ring. The brightest knots show strong similarities with classical blue compact dwarf galaxies. They are dominated by active star forming regions; their most recent starburst is younger than 5 Myr; we did not find evidences for the presence of an old underlying stellar population. NGC 5291 appears to be a maternity of extremely young objects most probably forming their first generation of stars. Born in pre-enriched gas clouds, these recycled galaxies have an oxygen abundance which is higher than BCDGs (Z⊙/3 on average) and which departs from the luminosity-metallicity relation observed for typical dwarf and giant galaxies. We propose this property as a tool to identify tidal dwarf galaxies (TDGs) among the dwarf galaxy population. Several TDGs in NGC 5291 exhibit strong velocity gradients in their ionized gas and may already be dynamically independent galaxies. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00046361_v333_n3_p813_Duc
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Galaxies: dwarf
Galaxies: formation
Galaxies: individual: NGC 5291
Galaxies: interactions
Galaxies: ISM
Radio lines: galaxies
spellingShingle Galaxies: dwarf
Galaxies: formation
Galaxies: individual: NGC 5291
Galaxies: interactions
Galaxies: ISM
Radio lines: galaxies
Duc, P.-A.
Mirabel, I.F.
Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
topic_facet Galaxies: dwarf
Galaxies: formation
Galaxies: individual: NGC 5291
Galaxies: interactions
Galaxies: ISM
Radio lines: galaxies
description NGC 5291 is an early type galaxy at the edge of the cluster Abell 3574 which drew the attention because of the unusual high amount of atomic gas (∼ 5 × 10110 M·) found associated to it. The HI is distributed along a huge and fragmented ring, possibly formed after a tidal interaction with a companion galaxy. We present multi-slit optical spectroscopic observations and optical/near-infrared images of the system. We show that NGC 5291 is a LINER galaxy exhibiting several remnants of previous merging events, in particular a curved dust lane and a counter-rotation of the gas with respect to the stars. The atomic hydrogen has undoubtly an external origin and was probably accreted by the galaxy from a gas-rich object in the cluster. It is unlikely that the HI comes from the closest companion of NGC 5291, the so-called "Seashell" galaxy, which appears to be a fly-by object at a velocity greater than 400 km s-1. We have analyzed the properties of 11 optical counterparts to the clumps observed in the HI ring. The brightest knots show strong similarities with classical blue compact dwarf galaxies. They are dominated by active star forming regions; their most recent starburst is younger than 5 Myr; we did not find evidences for the presence of an old underlying stellar population. NGC 5291 appears to be a maternity of extremely young objects most probably forming their first generation of stars. Born in pre-enriched gas clouds, these recycled galaxies have an oxygen abundance which is higher than BCDGs (Z⊙/3 on average) and which departs from the luminosity-metallicity relation observed for typical dwarf and giant galaxies. We propose this property as a tool to identify tidal dwarf galaxies (TDGs) among the dwarf galaxy population. Several TDGs in NGC 5291 exhibit strong velocity gradients in their ionized gas and may already be dynamically independent galaxies.
format JOUR
author Duc, P.-A.
Mirabel, I.F.
author_facet Duc, P.-A.
Mirabel, I.F.
author_sort Duc, P.-A.
title Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
title_short Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
title_full Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
title_fullStr Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
title_full_unstemmed Young tidal dwarf galaxies around the gas-rich disturbed lenticular NGC 5291
title_sort young tidal dwarf galaxies around the gas-rich disturbed lenticular ngc 5291
url http://hdl.handle.net/20.500.12110/paper_00046361_v333_n3_p813_Duc
work_keys_str_mv AT ducpa youngtidaldwarfgalaxiesaroundthegasrichdisturbedlenticularngc5291
AT mirabelif youngtidaldwarfgalaxiesaroundthegasrichdisturbedlenticularngc5291
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