2010ApJ...708.1335W

Query : 2010ApJ...708.1335W

2010ApJ...708.1335W - Astrophys. J., 708, 1335-1356 (2010/January-2)

The ages, metallicities, and alpha element enhancements of globular clusters in the elliptical NGC 5128: a homogeneous spectroscopic study with Gemini/Gemini multi-object spectrograph.

WOODLEY K.A., HARRIS W.E., PUZIA T.H., GOMEZ M., HARRIS G.L.H. and GEISLER D.

Abstract (from CDS):

We present new integrated light spectroscopy of globular clusters (GCs) in NGC 5128, a nearby giant elliptical galaxy less than 4 Mpc away, in order to measure radial velocities and derive ages, metallicities, and alpha-element abundance ratios. Using the Gemini South 8 meter telescope with the instrument Gemini Multi-Object Spectrograph, we obtained spectroscopy in the range of ∼3400-5700 Å for 72 GCs with a signal-to-noise ratio greater than 30 Å^–1; and we have also discovered 35 new GCs within NGC 5128 from our radial velocity measurements. We measured and compared the Lick indices from Hδ_A through Fe5406 with the single stellar population models of Thomas et al. in order to derive age, metallicity, and [α/Fe] values. We also measure Lick indices for 41 Milky Way GCs from Puzia et al. and Schiavon et al. with the same methodology for direct comparison. Our results show that 68% of the NGC 5128 GCs have old ages (>8 Gyr), 14% have intermediate ages (5-8 Gyr), and 18% have young ages (<5 Gyr). However, when we look at the metallicity of the GCs as a function of age, we find 92% of metal-poor GCs and 56% of metal-rich GCs in NGC 5128 have ages >8 Gyr, indicating that the majority of both metallicity subpopulations of GCs formed earlier, with a significant population of young and metal-rich GCs forming later. Our metallicity distribution function generated directly from spectroscopic Lick indices is clearly bimodal, as is the color distribution of the same set of GCs. Thus, the metallicity bimodality is real and not an artifact of the color to metallicity conversion. However, the metallicity distribution function obtained from comparison with the single stellar population models is consistent with a unimodal, bimodal, or multimodal shape. The [α/Fe] values are supersolar with a mean value of 0.14±0.04, indicating a fast formation timescale. However, the GCs in NGC 5128 are not as [α/Fe] enhanced as the Milky Way GCs also examined in this study. Our measured indices also indicate that the GCs in NGC 5128 may have a slight overabundance in nitrogen and a wider range of calcium strength compared to the Milky Way GCs. Our results support a rapid, early formation of the GC system in NGC 5128, with subsequent major accretion and/or GC and star-forming events in more recent times.

Abstract Copyright: ∼

Journal keyword(s): galaxies: elliptical and lenticular, cD - galaxies: evolution - galaxies: individual: NGC 5128 - galaxies: star clusters - globular clusters: general

VizieR on-line data: <Available at CDS (J/ApJ/708/1335): table2.dat table3.dat table4.dat table5.dat>

Nomenclature: Table 3: [WHB2007] GCNNNN (Nos 0445-0479) added.

Simbad objects: 152

Full paper

View the references in ADS

Number of rows : 152

N	Identifier	Otype	ICRS (J2000) RA	ICRS (J2000) DEC	Mag U	Mag B	Mag V	Mag R	Mag I	Sp type	#ref 1850 - 2026	#notes
1	M 31	AGN	00 42 44.330	+41 16 07.50	4.86	4.36	3.44			~	13622	1
2	CPD-69 177	WD*	03 10 31.0195960176	-68 36 03.380768388	10.757	11.413	11.394	11.47	11.558	DA3.0	299	0
3	NGC 1399	rG	03 38 29.083	-35 27 02.67	11.05	9.74	9.59	8.12		~	1636	1
4	NGC 3115	GiG	10 05 13.9270507008	-07 43 06.982712292		11		9.37		~	1067	2
5	M 105	LIN	10 47 49.600	+12 34 53.87		10.56	9.76	9.12	8.18	~	1504	0
6	LAWD 37	WD*	11 45 42.9169346379	-64 50 29.461957832	11.08	11.725	11.513	11.34	11.163	DQ	287	0
7	NGC 4038	EmG	12 01 53.002	-18 52 03.32		10.91		9.74	11.0	~	1364	1
8	NGC 4365	GiG	12 24 28.228	+07 19 03.07		11.5				~	871	0
9	[WHB2007] GC0445	GlC	13 24 40.5090180120	-43 01 56.775783072						~	4	0
10	[PFF2004] gc 15	GlC	13 24 41.1791356704	-43 01 45.681854700	20.27	20.01	19.22	18.74	18.15	~	8	0
11	[PFF2004] gc 17	GlC	13 24 43.6101147000	-42 58 16.407393024	20.54	20.32	19.51	18.99	18.47	~	9	0
12	[HGH2004] 201.18573-43.04646	GlC	13 24 44.575	-43 02 47.26	20.47	20.03	19.06	18.49	17.87	~	8	0
13	[BBP2008] AAT109711	GlC	13 24 45.3334279608	-42 59 33.527863572	19.88	19.87	19.30	18.90	18.33	~	6	0
14	[BBP2008] AAT109788	GlC	13 24 45.7546764408	-43 02 24.586946016	21.82	21.02	19.89	19.23	18.56	~	7	0
15	[PFF2004] gc 18	GlC	13 24 47.0744129520	-43 06 01.725201972	20.90	20.03	18.91	18.25	17.54	~	9	0
16	[HGH92] G277	GlC	13 24 47.3505541800	-42 58 29.852241996	20.26	19.96	19.10	18.56	18.02	~	11	0
17	[PFF2004] gc 19	GlC	13 24 48.9497083248	-42 57 48.466080216	20.10	19.87	19.05	18.53	18.00	~	7	0
18	[WHB2007] GC0446	GlC	13 24 50.4561450528	-43 04 51.130837056						~	4	0
19	[PFF2004] gc 20	GlC	13 24 50.4584232792	-42 59 49.048409328	20.57	20.33	19.53	19.00	18.47	~	6	0
20	[WHB2007] GC0447	GlC	13 24 50.90	-42 59 59.0						~	2	0
21	[VHH81] 100	*	13 24 52.0908678024	-43 04 32.825056656			20.08			~	8	0
22	[HGH92] G302	GlC	13 24 53.2677331056	-43 04 34.821786864	20.30	20.01	19.20	18.69	18.16	~	11	0
23	[WHB2007] GC0448	GlC	13 24 53.64	-42 57 59.1						~	4	0
24	[HGH2004] 201.22484-43.01212	GlC	13 24 53.9655096552	-43 00 43.675544232						~	6	0
25	[PFF2004] gc 22	GlC	13 24 54.3100763256	-43 03 15.525930816	20.72	20.58	19.84	19.37	18.90	~	11	0
26	[VHH81] 11	GlC	13 24 54.7069756200	-43 01 21.773072820	19.55	18.96	17.91	17.26	16.61	~	36	0
27	[WHB2007] GC0450	GlC	13 24 54.97	-43 02 52.4						~	2	0
28	[BBP2008] AAT111406	GlC	13 24 55.29	-43 03 15.6	21.84	21.15	20.13	19.50	18.80	~	4	0
29	[WHB2007] GC0451	GlC	13 24 55.4187265704	-42 59 48.554780424						~	4	0
30	[WHB2007] GC0420	GlC	13 24 55.9717301568	-43 02 15.898407684				19.87		~	5	0
31	[HGH92] G279	GlC	13 24 56.2459715304	-43 03 23.486053068	19.97	19.91	19.45	19.17	18.88	~	10	0
32	[VHH81] 31	GlC	13 24 57.4193525592	-43 01 08.176077660	20.09	19.42	18.38	17.75	17.06	~	15	0
33	[HGH92] G369	GlC	13 24 57.4971515520	-42 59 23.335006056	19.82	19.58	18.74	18.22	17.69	~	9	0
34	[PFF2004] gc 25	GlC	13 24 57.5363565120	-43 05 32.851539240	21.50	21.02	20.02	19.39	18.67	~	10	0
35	[WHB2007] GC0452	GlC	13 24 57.76	-42 58 51.6						~	4	0
36	[HGH2004] 201.24254-42.93612	GlC	13 24 58.1998428312	-42 56 10.050292680	19.34	18.73	17.71	17.10	16.44	~	33	0
37	[WHB2007] GC0453	GlC	13 24 58.5886901520	-42 58 16.595346936						~	4	0
38	[PFF2004] gc 27	GlC	13 25 00.6222187680	-43 05 30.351035688	21.22	20.75	19.74	19.13	18.45	~	9	0
39	[WHB2007] GC0103	GlC	13 25 01.5825588264	-42 54 40.818648816	19.97	19.75	19.37	19.06	18.71	~	16	1
40	[PFF2004] gc 30	GlC	13 25 01.7062428000	-43 00 09.899928036	21.68	20.94	19.89	19.26	18.54	~	6	0
41	[WHB2007] GC0454	GlC	13 25 02.82	-43 02 04.4						~	3	0
42	[KKF2001] J132503.04-425625.09	GlC	13 25 03.1140272880	-42 56 25.081996560	20.47	19.94	18.93	18.32	17.67	~	12	0
43	[HGH92] G 66	GlC	13 25 03.1550093352	-43 03 02.557624608	20.26	19.67	18.68	18.15	17.44	~	9	0
44	[BBP2008] AAT112752	GlC	13 25 04.1169827952	-43 00 19.694612016	20.51	20.16	19.34	18.88	18.44	~	5	0
45	2MASS J13250501-4257152	GlC	13 25 05.0117682000	-42 57 15.261735132	18.96	18.39	17.41	16.81	16.19	~	11	0
46	[WHB2007] GC0455	GlC	13 25 05.02	-43 01 33.6						~	3	0
47	[HGH92] G 35	GlC	13 25 05.2577366712	-42 58 05.757927312	21.02	20.59	19.62	19.01	18.41	~	9	0
48	[HGH92] G342	GlC	13 25 05.83	-42 59 00.6	19.65	19.14	18.18	17.57	16.96	~	8	0
49	[WHB2007] GC0456	GlC	13 25 06.72	-42 59 17.1						~	3	0
50	[WHB2007] GC0457	GlC	13 25 06.8237651448	-42 57 32.204141352						~	4	0
51	[WHB2007] GC0424	GlC	13 25 06.8744957760	-43 02 40.264354896						~	4	0
52	[BBP2008] AAT113428	GlC	13 25 07.3071215184	-43 06 20.654190684	21.25	20.92	20.04	19.49	18.93	~	6	0
53	[HHG2004] 18	GlC	13 25 07.62	-43 01 15.2	19.83	19.16	18.12	17.46	16.82	~	8	0
54	[WHB2007] GC0458	GlC	13 25 07.69	-42 55 49.6						~	4	0
55	[HHG2004] 47	GlC	13 25 08.5064319792	-43 02 57.523546284	20.59	19.95	18.91	18.37	17.64	~	12	0
56	[PFF2004] gc 38	GlC	13 25 08.8027915872	-43 04 14.971686636	20.83	20.29	19.29	18.69	18.03	~	6	0
57	[KKF2001] J132509.20-425859.64	GlC	13 25 09.20	-42 58 59.6	19.13	18.65	17.71	17.13	16.55	~	11	0
58	[WHB2007] GC0425	GlC	13 25 09.5917646976	-43 04 37.954510248				20.11		~	5	0
59	[CHP2004] J132510.2-425511	*	13 25 10.2379074816	-42 55 09.537130416	21.07	20.47	19.46	18.90	18.21	~	10	0
60	[HGH2004] 201.29642-43.05266	GlC	13 25 11.1423004224	-43 03 09.639856008	20.57	20.32	19.51	18.99	18.48	~	17	0
61	[HGH92] G 81	GlC	13 25 12.0906127944	-42 57 25.264183896	19.90	19.52	18.62	18.05	17.49	~	8	0
62	[R2001b] f2.GC-61	GlC	13 25 12.8712194544	-43 07 59.228291604	19.65	19.15	18.20	17.60	17.03	~	22	0
63	[R2001b] f2.GC-59	GlC	13 25 13.861	-43 07 32.56	22.13	21.70	20.70	20.11	19.48	~	8	0
64	[WHB2007] GC0426	GlC	13 25 14.180	-43 04 46.63				19.87		~	5	0
65	[HGH2004] 201.30934-43.12320	GlC	13 25 14.2360455192	-43 07 23.608131960	21.26	20.63	19.55	18.90	18.21	~	12	0
66	[BBP2008] AAT114769	GlC	13 25 15.0947544672	-42 57 45.669330072	21.20	21.00	20.25	19.76	19.25	~	6	0
67	[BBP2008] AAT114913	GlC	13 25 15.9042757656	-43 06 03.409213860	21.69	21.33	20.39	19.88	19.29	~	7	0
68	[PFF2004] gc 49	GlC	13 25 16.0488577200	-43 05 06.561261420	20.74	20.45	19.59	19.05	18.50	~	8	0
69	[WHB2007] GC0459	GlC	13 25 17.67	-42 56 13.9						~	3	0
70	[R2001b] f2.GC-47	GlC	13 25 19.95	-43 07 43.7	21.86	21.20	20.11	19.40	18.62	~	6	0
71	[WHB2007] GC0460	GlC	13 25 20.4076028664	-43 06 09.068952240						~	4	0
72	[BBP2008] AAT115679	GlC	13 25 20.6903564064	-43 06 35.963343360	21.93	21.49	20.44	19.80	19.15	~	9	0
73	[VHH81] 143	GlC	13 25 23.20	-43 03 12.9						~	7	0
74	[WHB2007] GC0461	GlC	13 25 23.97	-43 03 45.2						~	3	0
75	[HGH2004] 201.35622-42.94199	GlC	13 25 25.4847997272	-42 56 31.252602156	20.99	20.83	20.06	19.56	19.05	~	10	0
76	[HHG2004] 108	GlC	13 25 25.7274117864	-43 05 16.616129424	20.88	20.70	19.88	19.39	18.86	~	14	0
77	[VHH81] 46	*	13 25 25.9538242848	-43 03 25.765101648	19.74	19.71	19.10	18.74	18.30	~	8	0
78	[WHB2007] GC0463	GlC	13 25 27.2768160264	-42 58 28.845427980						~	4	0
79	[WHB2007] GC0464	GlC	13 25 27.43	-42 55 30.1						~	4	0
80	NAME Centaurus A	BLL	13 25 27.61521044	-43 01 08.8050291		8.18	6.84	6.66		~	4774	3
81	[KKF2001] J132528.04-430402.81	GlC	13 25 27.9708458640	-43 04 02.237343060	20.90	20.23	19.18	18.56	17.90	~	17	0
82	[WHH2005] 17	GlC	13 25 29.41	-42 57 42.7	19.68	19.39	18.57	18.06	17.48	~	6	0
83	[HGH92] G169	GlC	13 25 29.4167616960	-42 58 09.791031612	21.39	20.58	19.49	18.92	18.12	~	16	0
84	[HGH2004] 201.37341-42.91234	GlC	13 25 29.6146311264	-42 54 44.467864056	20.91	20.29	19.26	18.73	17.98	~	7	0
85	[HGH2004] 201.37531-42.94635	GlC	13 25 30.0697218360	-42 56 46.920259068	19.85	19.36	18.36	17.85	17.16	~	9	0
86	[R2001b] f2.GC-28	GlC	13 25 30.16	-43 06 54.7			21.49			~	9	0
87	[WHB2007] GC0466	GlC	13 25 30.3259265880	-43 05 42.808029144						~	3	0
88	[WHB2007] GC0467	GlC	13 25 30.9568018864	-42 58 36.940304008						~	3	0
89	[WHB2007] GC0468	GlC	13 25 31.26	-42 55 47.6						~	3	0
90	[BBP2008] AAT117322	GlC	13 25 31.725	-42 55 15.60	21.14	20.91	20.08	19.55	19.07	~	8	0
91	[WHB2007] GC0469	GlC	13 25 31.73	-42 59 57.4						~	2	0
92	CXOU J132532.4-425851	GlC	13 25 32.4107952984	-42 58 50.114330616	20.44	19.86	18.86	18.24	17.64	~	18	0
93	[R2001b] f2.GC-23	GlC	13 25 32.7853774512	-43 07 02.294656032	20.08	19.67	18.77	18.23	17.64	~	23	0
94	[KKF2001] J132532.80-425623.83	GlC	13 25 32.7943454208	-42 56 24.336937068	19.62	19.43	18.64	18.15	17.64	~	11	0
95	[HGH2004] 201.38693-43.07476	GlC	13 25 32.88	-43 04 29.2	21.23	20.44	19.37	18.77	18.12	~	14	0
96	[WHB2007] GC0470	GlC	13 25 33.1000	-42 54 56.965						~	3	0
97	[KKF2001] J132533.95-425859.53	GlC	13 25 34.0914079936	-42 59 00.629564094	20.68	20.09	19.10	18.58	17.91	~	15	0
98	[VHH81] 45	GlC	13 25 34.244	-42 56 58.96	19.99	19.81	19.03	18.60	18.05	~	10	0
99	[VHH81] 154	Gl?	13 25 34.71	-43 03 30.2						~	6	0
100	[HGH2004] 201.39633-42.94587	GlC	13 25 35.1130929792	-42 56 45.197051424	19.67	19.47	18.68	18.19	17.70	~	9	0
101	[HHG2004] 35	GlC	13 25 35.31	-43 05 29.0			18.63			~	10	0
102	[KKF2001] J132535.52-425935.16	GlC	13 25 35.52	-42 59 35.2	20.76	20.18	19.17	18.68	17.94	~	13	0
103	[BBP2008] AAT118198	GlC	13 25 37.4515217880	-43 05 44.994607044	21.49	20.68	19.64	18.98	18.29	~	9	0
104	[VHH81] 17	GlC	13 25 39.7188791400	-42 55 59.137358376	18.82	18.51	17.63	17.10	16.57	~	36	0
105	[CFW90] Star 33	GlC	13 25 39.88	-43 05 01.9	18.79	18.42	17.53	16.97	16.43	~	24	0
106	[R2001b] f2.GC-3	GlC	13 25 40.8914082360	-43 08 16.059548796	20.66	20.56	19.84	19.36	18.88	~	12	0
107	[BBP2008] AAT118874	GlC	13 25 41.3462125200	-42 58 08.926264128	21.55	21.02	19.99	19.43	18.81	~	7	0
108	[WHB2007] GC0436	GlC	13 25 41.7076271342	-42 58 31.650670648						~	4	0
109	[WHB2007] GC0471	GlC	13 25 42.110	-42 57 24.35						~	4	0
110	[HGH92] G370	GlC	13 25 42.2393866248	-42 59 16.933062264	19.61	19.29	18.39	17.86	17.32	~	11	0
111	[HGH2004] 201.42676-42.98402	GlC	13 25 42.4192846632	-42 59 02.553635112	20.11	19.74	18.81	18.24	17.66	~	8	0
112	[BBP2008] AAT119508	GlC	13 25 42.5086836792	-43 03 41.504261328	21.85	21.42	20.39	19.77	19.18	~	11	0
113	[WHB2007] GC0472	GlC	13 25 42.98	-43 00 00.2						~	2	0
114	[WHB2007] GC0473	GlC	13 25 43.09	-43 00 05.2						~	3	0
115	[CHP2004] J132543.2-425838	GlC	13 25 43.2127484136	-42 58 37.341784488	21.13	20.46	19.42	18.83	18.18	~	12	0
116	[VHH81] 19	GlC	13 25 43.3840630536	-43 07 22.928276928	19.37	19.01	18.12	17.59	17.03	~	17	0
117	[VHH81] 35	*	13 25 44.1991095867	-42 58 59.376172980	19.92	19.51	18.58	18.01	17.43	~	9	0
118	[WHB2007] GC0474	GlC	13 25 44.6569434464	-42 58 24.222438362						~	3	0
119	[HGH2004] 201.44127-42.95560	GlC	13 25 45.9015147936	-42 57 20.182619700	19.26	19.12	18.37	17.89	17.41	~	9	0
120	[HGH2004] 201.44165-42.94805	GlC	13 25 45.9960305544	-42 56 53.017724076	20.64	20.43	19.63	19.12	18.62	~	9	0
121	[BBP2008] AAT119596	GlC	13 25 46.06	-43 08 24.5	21.19	20.69	19.70	19.10	18.51	~	5	0
122	[WHB2007] GC0475	GlC	13 25 46.36	-43 04 44.6						~	2	0
123	[HGH92] G284	GlC	13 25 46.59	-42 57 03.0	21.47	20.89	19.87	19.28	18.63	~	17	0
124	[WHB2007] GC0476	GlC	13 25 47.0642410289	-42 57 49.565171408						~	3	0
125	[PFF2004] gc 66	GlC	13 25 47.1280788384	-43 06 08.914611240	21.21	20.82	19.92	19.37	18.80	~	12	0
126	[HGH92] G357	GlC	13 25 47.82	-43 00 42.5	20.87	20.55	19.71	19.24	18.71	~	7	0
127	[WHB2007] GC0477	GlC	13 25 47.83	-42 57 32.6						~	2	0
128	[HGH92] G251	GlC	13 25 48.54	-42 57 41.2	20.50	19.93	18.93	18.33	17.69	~	9	0
129	[HGH2004] 201.45511-43.00060	G	13 25 49.33	-42 59 59.8						~	6	0
130	[HGH2004] 201.45976-43.06896	GlC	13 25 50.3479376568	-43 04 08.350669812	21.33	20.93	19.97	19.42	18.83	~	10	0
131	[HGH2004] 201.45995-42.96731	GlC	13 25 50.3863311504	-42 58 02.299915668	20.39	20.23	19.42	18.94	18.45	~	10	0
132	[BBP2008] AAT120355	GlC	13 25 50.45	-43 00 30.6	21.26	21.14	20.42	20.02	19.58	~	7	0
133	[BBP2008] AAT120515	GlC	13 25 51.2845842000	-42 59 29.430545172	21.11	20.81	19.92	19.38	18.81	~	8	0
134	[HGH2004] 201.46468-42.99635	GlC	13 25 51.5216184934	-42 59 46.887279730	20.79	20.59	19.82	19.34	18.83	~	7	0
135	[HGH2004] 201.46718-42.97503	GlC	13 25 52.1214238695	-42 58 30.129186260	20.68	20.45	19.62	19.12	18.54	~	8	0
136	[HGH2004] 201.46985-42.97823	GlC	13 25 52.7648463624	-42 58 41.641857804	21.36	20.94	19.97	19.38	18.74	~	10	0
137	[HGH2004] 201.47281-43.06573	GlC	13 25 53.4795059064	-43 03 56.718308952	20.96	20.45	19.48	18.90	18.28	~	9	0
138	[VHH81] 22	GlC	13 25 53.5504608507	-42 59 07.532093559	19.39	19.06	18.15	17.62	17.07	~	33	0
139	[BBP2008] AAT120976	GlC	13 25 54.2747706984	-42 56 20.493407976	21.51	21.23	20.38	19.84	19.27	~	11	0
140	CXOU J132554.5-425924	GlC	13 25 54.5684562024	-42 59 25.329473880	18.92	18.29	17.22	16.62	15.95	~	49	0
141	[VHH81] 103	GlC	13 25 54.9985209552	-42 59 13.887422828			18.88			~	7	0
142	[HGH92] G143	GlC	13 25 58.6659472248	-43 07 11.094298536	20.31	20.02	19.21	18.68	18.18	~	9	0
143	[WRW2015] 780	GlC	13 25 59.98	-42 59 57.9						~	4	0
144	[VHH81] 7	GlC	13 26 05.3936216880	-42 56 32.376406056	18.38	18.03	17.17	16.65	16.23	~	42	0
145	[HGH2004] 201.52664-43.01059	GlC	13 26 06.3966548208	-43 00 38.139117840	20.39	20.20	19.43	18.99	18.47	~	9	0
146	[HGH92] G170	GlC	13 26 06.93	-42 57 35.1	20.78	20.21	19.22	18.65	17.97	~	12	0
147	NGC 5846	rG	15 06 29.253	+01 36 20.29		11.9		9.74		~	891	2
148	M 10	GlC	16 57 09.05	-04 06 01.1			4.98			~	857	0
149	NAME Baade Window	reg	18 03.5	-30 01						~	643	3
150	NGC 6553	GlC	18 09 15.68	-25 54 27.9		9.08				~	644	0
151	M 72	GlC	20 53 27.70	-12 32 14.3			8.96			~	465	0
152	NGC 7192	Sy2	22 06 50.1107894976	-64 18 58.721070096		12.21	11.21	10.77		~	148	0

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