Capture of field stars by giant interstellar clouds: the formation of moving stellar groups

In the solar neighbourhood, there are moving groups of stars with similar ages and others of stars with heterogeneous ages as the field stars. To explain these facts, we have constructed a simple model of three phases. Phase A: a giant interstellar cloud is uniformly accelerated (or decelerated) wit...

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Detalles Bibliográficos
Autor principal:	Olano, Carlos Alberto
Formato:	Articulo
Lenguaje:	Inglés
Publicado:	2015
Materias:	Ciencias Astronómicas Galaxy: kinematics and dynamics ISM: clouds Open clusters and associations: general Solar neighbourhood Stars: kinematics and dynamics Sun: general
Acceso en línea:	http://sedici.unlp.edu.ar/handle/10915/86024
Aporte de:	SEDICI (UNLP) de Universidad Nacional de La Plata

id	I19-R120-10915-86024
record_format	dspace
institution	Universidad Nacional de La Plata
institution_str	I-19
repository_str	R-120
collection	SEDICI (UNLP)
language	Inglés
topic	Ciencias Astronómicas Galaxy: kinematics and dynamics ISM: clouds Open clusters and associations: general Solar neighbourhood Stars: kinematics and dynamics Sun: general
spellingShingle	Ciencias Astronómicas Galaxy: kinematics and dynamics ISM: clouds Open clusters and associations: general Solar neighbourhood Stars: kinematics and dynamics Sun: general Olano, Carlos Alberto Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
topic_facet	Ciencias Astronómicas Galaxy: kinematics and dynamics ISM: clouds Open clusters and associations: general Solar neighbourhood Stars: kinematics and dynamics Sun: general
description	In the solar neighbourhood, there are moving groups of stars with similar ages and others of stars with heterogeneous ages as the field stars. To explain these facts, we have constructed a simple model of three phases. Phase A: a giant interstellar cloud is uniformly accelerated (or decelerated) with respect to the field stars during a relatively short period of time (10 Myr) and the cloud's mass is uniformly increased. As a result, a number of passing field stars is gravitationally captured by the cloud at the end of this phase; phase B: the acceleration (or deceleration) and mass accretion of the cloud cease. The star formation spreads throughout the cloud, giving origin to stellar groups of similar ages; and phase C: the cloud loses all its gaseous component at a constant rate and in parallel is uniformly decelerated (or accelerated) until reaching the initial velocity of phase A (case 1) or the velocity of the gas cloud remains constant (case 2). Both cases give equivalent results. The system equations for the star motions governed by a time-dependent gravitational potential of the giant cloud and referred to a coordinate system comoving with the cloud have been solved analytically. We have assumed a homogeneous spheroidal cloud of fixed semimajor axis a = 300 pc and of an initial density of 7 atoms cm<SUP>-3</SUP>, with a density increment of 100 per cent and a cloud's velocity variation of 30 km s<SUP>-1</SUP>, from the beginning to the end of phase A. The result is that about 4 per cent of the field stars that are passing within the volume of the cloud at the beginning of phase A are captured. The Sun itself could have been captured by the same cloud that originated the moving groups of the solar neighbourhood.
format	Articulo Articulo
author	Olano, Carlos Alberto
author_facet	Olano, Carlos Alberto
author_sort	Olano, Carlos Alberto
title	Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
title_short	Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
title_full	Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
title_fullStr	Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
title_full_unstemmed	Capture of field stars by giant interstellar clouds: the formation of moving stellar groups
title_sort	capture of field stars by giant interstellar clouds: the formation of moving stellar groups
publishDate	2015
url	http://sedici.unlp.edu.ar/handle/10915/86024
work_keys_str_mv	AT olanocarlosalberto captureoffieldstarsbygiantinterstellarcloudstheformationofmovingstellargroups
bdutipo_str	Repositorios
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Capture of field stars by giant interstellar clouds: the formation of moving stellar groups

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