Gas expulsion in massive star clusters? - Constraints from observations of young and gas-free objects

Free Access

Table 1

Observational data and results of gas expulsion simulations for the YMC sample of Bastian et al. (2014).

Galaxy	Cluster	Age^a	M _∗ ^b	r _h ^c	C ₅ ^d	Z ^e	Ex/	Ex/	ϵ _SF,W,c ^g	t _ex,w ^h
		(Myr)	(10⁵ M_⊙)	(pc)		(Z_⊙)	W^f	SN^f	(%)	(Myr)

NGC 6946	1447	12 ± 2.5	8	17.4	0.46	0.5	Y	Y	20	0.63
NGC 1569	A	6 ± 1	7.6	1.5	5.1	0.4	N	N	80	0.12
	B	15 ± 5	14	2.4	5.9	0.4	N	N	80	0.13
NGC 1705	1	12.5 ± 2.5	11	1.5	7.3	0.33	N	N	80	0.12
NGC 1140	1	5 ± 1	11	14	0.79	0.5	Y	Y	30	0.48
The Antennae	T352/W38220	4 ± 2	9.2	4.1	2.2	1	N	N	40	0.20
	Knot S	5 ± 1	16	14	1.1	1	N	Y	40	0.52
ESO 338-IG04	Cluster 23		50	8.9	5.6	0.2	N	N	80	0.22

Notes.

^(h)

Time since the coeval starburst at which an eventually escaping shell crosses the half-mass radius, for the stellar wind case with ϵ_SF,W,c.

^(a)

Age in Myr.

^(b)

Fiducial stellar mass, adopting the photometric mass estimate from Bastian et al. (2014).

^(c)

r_h: half-mass radius, calculated from the half-light radius assuming a Plummer sphere.

^(d)

Compactness index C₅ = (M_∗/10⁵ M_⊙)(r_h/pc)^-1.

^(e)

Metallicity.

^(f)

Success of gas expulsion assuming 30 per cent star formation efficiency by, respectively, stellar winds (Ex/W) and supernovae (Ex/SN). Y: yes, N: no.

^(g)

Critical star formation efficiency for gas expulsion in the metallicity dependent massive-star wind scenario. With this efficiency, a supershell would just not yet escape. The simulation at a star formation efficiency ten percentiles higher then features successful gas expulsion.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.