2010ApJ...722...20C

Query : 2010ApJ...722...20C

2010ApJ...722...20C - Astrophys. J., 722, 20-32 (2010/October-2)

Identification of faint Chandra X-ray sources in the core-collapsed globular cluster NGC 6397: evidence for a bimodal cataclysmic variable population.

COHN H.N., LUGGER P.M., COUCH S.M., ANDERSON J., COOL A.M., VAN DEN BERG M., BOGDANOV S., HEINKE C.O. and GRINDLAY J.E.

Abstract (from CDS):

We have searched for optical identifications for 79 Chandra X-ray sources that lie within the half-mass radius of the nearby, core-collapsed globular cluster NGC 6397, using deep Hubble Space Telescope Advanced Camera for Surveys Wide Field Channel imaging in Hα, R, and B. Photometry of these images allows us to classify candidate counterparts based on color-magnitude diagram location. In addition to recovering nine previously detected cataclysmic variables (CVs), we have identified six additional faint CV candidates, a total of 42 active binaries (ABs), two millisecond pulsars, one candidate active galactic nucleus, and one candidate interacting galaxy pair. Of the 79 sources, 69 have a plausible optical counterpart. The 15 likely and possible CVs in NGC 6397 mostly fall into two groups: a brighter group of six for which the optical emission is dominated by contributions from the secondary and accretion disk and a fainter group of seven for which the white dwarf dominates the optical emission. There are two possible transitional objects that lie between these groups. The faintest CVs likely lie near the minimum of the CV period distribution, where an accumulation is expected. The spatial distribution of the brighter CVs is much more centrally concentrated than those of the fainter CVs and the ABs. This may represent the result of an evolutionary process in which CVs are produced by dynamical interactions, such as exchange reactions, near the cluster center and are scattered to larger orbital radii, over their lifetimes, as they age and become fainter.

Abstract Copyright: ∼

Journal keyword(s): globular clusters: individual: NGC 6397 - novae, cataclysmic variables - X-rays: binaries

Nomenclature: Table 1: [CGC95] NN (Nos 10-15) added.

Errata: erratum vol. 930, art. 96 (2022)

Simbad objects: 86

goto Full paper

goto View the references in ADS

Number of rows : 86
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 NGC 104 GlC 00 24 05.359 -72 04 53.20     4.09     ~ 4158 0
2 NGC 5139 GlC 13 26 47.28 -47 28 46.1           ~ 3677 0
3 M 4 GlC 16 23 35.22 -26 31 32.7           ~ 1978 0
4 [GHE2001b] U111 X 17 40 29.845 -53 40 26.99           ~ 3 0
5 [GHE2001b] U62 XB? 17 40 30.422 -53 39 17.47   23.33   20.90   ~ 3 0
6 [GHE2001b] U63 XB? 17 40 31.663 -53 38 46.36   20.39   18.15   ~ 3 0
7 [GHE2001b] U110 XB* 17 40 33.455 -53 39 16.83   22.04   19.92   ~ 3 0
8 [GHE2001b] U121 X 17 40 33.631 -53 39 34.96           ~ 3 0
9 [GHE2001b] U107 XB* 17 40 34.115 -53 40 17.01   21.63   19.61   ~ 3 0
10 [CGC95] 11 CV* 17 40 34.202 -53 41 15.28   23.93   23.32   ~ 5 0
11 [GHE2001b] U103 XB* 17 40 35.698 -53 40 12.56   21.05   19.26   ~ 3 0
12 [GHE2001b] U105 XB* 17 40 36.521 -53 41 07.85   21.84   19.78   ~ 3 0
13 [GHE2001b] U86 XB? 17 40 37.473 -53 41 47.24   24.06   21.16   ~ 3 0
14 [GHE2001b] U65 XB? 17 40 37.558 -53 39 17.85   21.27   18.72   ~ 3 0
15 [GHE2001b] U100 XB* 17 40 38.201 -53 40 46.55   23.14   20.81   ~ 3 0
16 [GHE2001b] U102 XB* 17 40 38.845 -53 39 43.12   23.80   21.27   ~ 3 0
17 CGKB A CV* 17 40 38.904 -53 39 51.09   24.73   22.72   ~ 9 0
18 [GHE2001b] U66 XB? 17 40 38.918 -53 38 49.80   24.56   21.93   ~ 3 0
19 Cl* NGC 6397 SAW V24 XB* 17 40 39.097 -53 40 23.09   17.07 16.45 18.40   ~ 6 0
20 [GHE2001b] U67 XB* 17 40 40.065 -53 40 16.59   21.17   19.34   ~ 4 0
21 [GHE2001b] U95 XB? 17 40 40.320 -53 40 44.58   23.02   20.81   ~ 3 0
22 Cl* NGC 6397 PCBY 4 BY* 17 40 40.543 -53 40 22.79   19.03   17.68   ~ 7 0
23 [GHE2001b] U68 X 17 40 40.730 -53 38 32.63           ~ 3 0
24 [GHE2001b] U69 XB* 17 40 40.867 -53 40 17.17   19.03   17.84   ~ 6 0
25 [GHE2001b] U98 XB* 17 40 40.994 -53 40 58.40   21.09   19.18   ~ 3 0
26 [CGC95] 7 Em* 17 40 41.076 -53 40 26.98   20.18   20.12   ~ 7 0
27 [CGC95] 13 CV? 17 40 41.237 -53 40 25.79   23.44   23.48   ~ 7 0
28 [GHE2001b] U119 X 17 40 41.261 -53 40 19.35           ~ 4 0
29 CGKB B LXB 17 40 41.468 -53 40 04.43           ~ 25 0
30 [GHE2001b] U118 X 17 40 41.576 -53 40 15.88   16.60   15.60   ~ 4 0
31 Cl* NGC 6397 SAW V12 CV* 17 40 41.597 -53 40 19.30   18.51 17.95 17.88   ~ 23 0
32 Cl* NGC 6397 LOAM 6 V* 17 40 41.6946306040 -53 40 33.309371811   16.28 15.82 15.50   ~ 10 0
33 [CGC95] 5 Em* 17 40 41.701 -53 40 29.00   21.50   20.15   ~ 13 0
34 Cl* NGC 6397 PCBY 6 XB* 17 40 41.779 -53 40 14.42   19.88   18.45   ~ 6 0
35 [CGC95] 4 Em* 17 40 41.830 -53 40 21.37   20.94   19.82   ~ 13 0
36 NGC 6397 GlC 17 40 42.09 -53 40 27.6     5.17     ~ 2103 0
37 [GHE2001b] U117 XB* 17 40 42.153 -53 40 25.56   17.84   16.82   ~ 4 0
38 [GHE2001b] U116 XB* 17 40 42.236 -53 40 19.97   19.49   18.18   ~ 4 0
39 Cl* NGC 6397 SAW V34 CV* 17 40 42.306 -53 40 28.70   20.02   18.87   ~ 25 0
40 [GHE2001b] U93 X 17 40 42.393 -53 40 46.62           ~ 3 0
41 [GHE2001b] U91 * 17 40 42.430 -53 40 41.65   20.44   18.94   ~ 3 0
42 Cl* NGC 6397 SAW V31 El? 17 40 42.6230201282 -53 40 27.291274010   16.41 15.95 16.10   ~ 22 0
43 [GHE2001b] U16 X 17 40 42.636 -53 42 15.24           ~ 4 0
44 V* V1139 Ara CV* 17 40 42.651 -53 40 19.30   19.10   18.52   ~ 22 0
45 [GHE2001b] U73 XB* 17 40 42.681 -53 39 28.73   19.47   18.19   ~ 4 0
46 [CGC98] NF 3 CV* 17 40 42.722 -53 40 27.53   20.04 19.35 20.21   ~ 16 0
47 [GHE2001b] U113 X 17 40 42.764 -53 40 20.76           ~ 4 0
48 [GHE2001b] U94 XB* 17 40 42.868 -53 40 49.07   20.58   18.88   ~ 3 0
49 Cl* NGC 6397 PCBY 2 BY* 17 40 42.873 -53 40 34.12   18.53   17.25   ~ 5 0
50 Cl* NGC 6397 PCBY 3 XB* 17 40 42.877 -53 40 26.45   18.69   17.46   ~ 5 0
51 Cl* NGC 6397 SAW V26 XB* 17 40 43.059 -53 38 31.29   17.40 16.19 15.52   ~ 6 0
52 [GHE2001b] U104 X 17 40 43.124 -53 39 29.04           ~ 3 0
53 Cl* NGC 6397 SAW V35 XB* 17 40 43.328 -53 41 55.46   19.59 18.70 18.31   ~ 6 0
54 [GHE2001b] U114 X 17 40 43.469 -53 40 34.34       19.49   ~ 3 0
55 [GHE2001b] U89 XB* 17 40 43.613 -53 40 24.60   21.82   19.76   ~ 3 0
56 [GHE2001b] U75 XB* 17 40 43.666 -53 40 30.61   21.78   19.71   ~ 4 0
57 [GHE2001b] U106 X 17 40 43.737 -53 39 17.52           ~ 3 0
58 Cl* NGC 6397 SAW V17 XB* 17 40 43.818 -53 41 16.32   16.81 16.17 15.81   ~ 8 0
59 [GHE2001b] U97 X 17 40 43.918 -53 40 05.90   22.88   20.90   ~ 4 0
60 Cl* NGC 6397 SAW V7 EB* 17 40 43.9199366001 -53 40 35.292617809   17.74 17.09 16.72   ~ 16 0
61 [CGC95] 8 CV* 17 40 44.084 -53 40 39.17   24.33   24.00   ~ 14 0
62 Cl* NGC 6397 SAW V36 XB? 17 40 44.12 -53 42 11.5   17.11 16.52     ~ 7 0
63 Cl* NGC 6397 PCWD 1 EB* 17 40 44.58 -53 40 25.3   17.75 17.09 16.73   ~ 8 0
64 PSR J1740-5340 Psr 17 40 44.589 -53 40 40.90   17.43   16.25   ~ 157 2
65 Cl* NGC 6397 SAW V16 El* 17 40 44.615 -53 40 41.59   17.36 16.65     ~ 22 1
66 [GHE2001b] U41 * 17 40 45.008 -53 39 55.21   17.69   16.74   ~ 4 0
67 [CGC95] 12 CV? 17 40 45.223 -53 40 28.60   23.19   22.08   ~ 6 0
68 [GHE2001b] U101 XB? 17 40 45.399 -53 41 01.40   19.94   18.48   ~ 3 0
69 [GHE2001b] U11 CV* 17 40 45.781 -53 40 41.52   24.26   23.65   ~ 11 0
70 [GHE2001b] U79 XB* 17 40 46.409 -53 40 04.05   21.98   19.82   ~ 3 0
71 [GHE2001b] U99 XB* 17 40 46.431 -53 40 30.40   19.96   18.49   ~ 3 0
72 [CGC95] 14 CV? 17 40 46.455 -53 41 56.50   25.84   25.40   ~ 5 0
73 Cl* NGC 6397 SAW V14 XB* 17 40 46.481 -53 41 15.44   20.21 19.19 18.62   ~ 7 0
74 [GHE2001b] U120 XB? 17 40 46.517 -53 40 15.64   23.70   21.09   ~ 3 0
75 [CGC95] 9 CV* 17 40 47.807 -53 41 28.40   23.63   23.38   ~ 13 0
76 [GHE2001b] U122 X 17 40 47.903 -53 39 24.83           ~ 3 0
77 Cl* NGC 6397 WFBY 2-1 XB* 17 40 48.537 -53 39 39.53   20.29   18.72   ~ 4 0
78 Cl* NGC 6397 SAW V13 EB* 17 40 48.978 -53 39 48.62   20.14 19.43 19.14   ~ 11 0
79 [CGC95] 15 CV? 17 40 49.615 -53 40 43.02   27.18   26.22   ~ 5 0
80 [GHE2001b] U123 X 17 40 49.621 -53 38 45.93           ~ 3 0
81 [GHE2001b] U112 * 17 40 50.374 -53 39 06.00   21.25   19.60   ~ 3 0
82 [GHE2001b] U108 X 17 40 52.099 -53 39 48.25           ~ 4 0
83 [GHE2001b] U109 XB? 17 40 52.728 -53 40 52.88   21.83   19.77   ~ 3 0
84 [CGC95] 10 CV* 17 40 52.807 -53 41 21.89   23.44   22.58   ~ 6 0
85 Cl* NGC 6397 SAW V30 EB* 17 40 54.531 -53 40 44.57   18.64 17.36     ~ 6 0
86 [GHE2001b] U84 XB? 17 40 54.807 -53 40 19.79   17.27       ~ 3 0

To bookmark this query, right click on this link: simbad:objects in 2010ApJ...722...20C and select 'bookmark this link' or equivalent in the popup menu