GC ULXs catalogue

Catalogue of ultraluminous X-ray sources in extragalactic globular clusters

This table lists all known ultraluminous X-ray sources (with detected X-ray emission above \(10^{39}\) erg/s) in extragalactic globular clusters, along with their observed X-ray and optical properties.

Source Properties:

X-ray Spectral Shape: XX keV = characteristic inner disk temperature, XX = best fit power-law index
Behaviour: N=no statistically significant variability, T = transient, FV = variable (within an observation), LV=variable (over many years)
Optical Counterpart: C=spectroscopically confirmed, PC=photometric candidate
Optical Emission: ? = no constraints placed, ND=none detected above cluster continuum
Notes: U = ultracompact, R Cor Bor = R Corona Borealis Star, BH=black hole candidate, UCD=ultracompact dwarf galaxy

Name	Host galaxy	Peak L_X	X-ray Spectrum	Behaviour	Counterpart	Optical Emission	Magnitude (z)	Colour (g-z)	r_H (pc)	Notes	References
RZ2109	NGC 4472	3e39	0.15 keV	FV, LV	C	[OIII]	20.4	0.84		BH?, U?	Maccarone et al., 2007
CXOKMZJ033831.7-353058	NGC 1399	2e39	0.3 keV	FV,T	C	?	22.02(R)	2.04(C-R)			Shih et al., 2010
CXOJ033831.8-352604	NGC 1399	2e39	0.4 keV	LV?	C	[OIII],[NII]	21.275	1.6		R Cor Bor?	Irwin et al., 2010
CXOUJ1229410+075744	NGC 4472	3e39	1.5 keV	LV	C	ND	20.8	1.59		BH?	Maccarone et al., 2011
CXOUJ124346.9+113234	NGC 4649	2e39	1.5	LV	C	ND	20.3	1.55			Roberts et al., 2012
CXOU1229345+0800320	NGC 4472	1e39	1.3keV	N	PC	?	22.1	0.92			Dage et al., 2019
CXOU1229423+08000808	NGC 4472	1e39	1.3keV	N	PC	?	19.5	1.11			Dage et al., 2019
CXOUJ1229345+0758515	NGC 4472	1e39	1.5	N	PC	?	20.1	1.55			Dage et al., 2019
CXOU1243445+11315	NGC 4649	1e39	1.5	N	PC	?	22.2	1.6			Dage et al., 2019
CXOUJ1243445+11315	NGC 1399	4e39	1.3	LV	C	?	20.49	1.37			Dage et al., 2019
SC302	M87	1.5e39	1.0 keV	FV	C	?	19.76	1.01		UCD?	Dage et al., 2020
CXOUJ123054.9+122438.5	M87	1e39	0.8 keV	LV	PC	?	22.56	1.70	1.88		Dage et al., 2020
CXOUJ123049.24+122334.5	M87	0.8e39	0.6 keV	LV	PC	?	21.66	1.08	2.20		Dage et al., 2020
CXOUJ123047.12+122416.0	M87	1.6e39	0.5 keV	LV?	PC	?	21.73/22.55	1.05/1.61	3.69/1.96		Dage et al., 2020
CXOUJ123050.1+122301.1	M87	1e39	1.0 keV	LV	PC	?	20.47	1.29	1.82		Dage et al., 2020
CXOUJ123049.9+122400.1	M87	1.1e39	1.5	N?	PC	?	20.85	1.42	2.53		Dage et al., 2020
CXOUJ123041.7+122440.1	M87	1e39	1.5 keV	N?	PC	?	20.41	1.24	2.70		Dage et al., 2020
CXOUJ032242.5-371222	NGC 1316	1.4e39	1.6keV	N	PC	?	20.88	1.67			Dage et al., 2021
CXOUJ032241.0-371235.3	NGC 1316	1e39	1.3keV	N	PC	?	21.98	1.49			Dage et al., 2021
CXOUJ032240.8-371224	NGC 1316	2e39	0.7-2.0 keV	N	PC	?	23.10	0.94			Dage et al., 2021