J/A+A/661/A35 eROSITA study of 47 Tuc globular cluster (Saeedi+, 2022)
eROSITA study of the globular cluster 47 Tucanae.
Saeedi S., Liu T., Knies J., Sasaki M., Becker W., Bulbul E., Dennerl K.,
Freyberg M., Laktionov R., Merloni A.
<Astron. Astrophys. 661, A35 (2022)>
=2022A&A...661A..35S 2022A&A...661A..35S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Binaries, X-ray ; Photometry, infrared ;
Optical
Keywords: globular clusters: general - X-rays: binaries -
binaries: symbiotics - novae, cataclysmic variables
Abstract:
We present the results of the analysis of five observations of the
globular cluster 47 Tucanae (47 Tuc) with eROSITA (extended
Roentgen Survey with an Imaging Telescope Array) on board
Spektrum-Roentgen-Gamma (Spektr-RG, SRG). The aim of the work is the
study of the X-ray population in the field of one of the most massive
globular clusters in our Milky Way. We focused on the classification
of point-like sources in the field of 47 Tuc. The unresolved dense
core of 47 Tuc (1.7' radius) and also the sources, which show
extended emission are excluded in this study.
We applied different methods of X-ray spectral and timing analysis
together with multi wavelength studies for the classification of the
X-rays sources in the field of 47 Tuc.
We detected 888 point-like sources in the energy range of
0.2-5.0keV. We identified 126 background AGNs and 25 foreground
stars. One of the foreground stars is classified as a variable M
dwarf. We also classified 14 X-ray sources as members of 47 Tuc,
including 1 symbiotic stars, 2 quiescent low mass X-ray binaries, and
4 cataclysmic variable. There are also 5 X-ray sources, which can
either be a cataclysmic variable or a contact binary, and also 1 X-ray
sources which can be an active binary (Type RS CVn). We identified one
X-ray binary, which belongs to the Small Magellanic Cloud. Moreover,
we calculated the X-ray luminosity function of 47 Tuc. No significant
population that seems to belong to the globular cluster has been
observed in the energy range of 0.5-2.0keV using eROSITA
observations.
Description:
We have analysed 5 observations of eROSITA taken in the Calibration
and Performance Verification (CalPV, Predehl et al.,
2021A&A...647A...1P 2021A&A...647A...1P) phase in 2019.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 185 888 X-ray sources in the FOV of 47 Tuc
tableb2.dat 89 649 Infrared magnitudes of counterparts of X-ray
sources of 47 tuc in different energy filters
2MASS and WISE surveys
tableb3.dat 89 125 Optical magnitudes of counterparts of X-ray
sources of 47 Tuc in Gaia and SkyMapper
Southern Sky Survey
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See also:
J/A+A/661/A1 : The eFEDS X-ray catalogs (V7.4) (Brunner+, 2022)
J/A+A/661/A2 : Galaxy clusters and groups in eFEDS (Liu+, 2022)
J/A+A/661/A3 : eFEDS counterparts to point-like sources (Salvato+, 2022)
J/A+A/661/A4 : eFEDS optical cluster and group catalog (Klein+, 2022)
J/A+A/661/A5 : The eFEDS AGN catalog (Liu+, 2022)
J/A+A/661/A7 : X-ray properties of eFEDS clusters and groups (Bahar+, 2022)
J/A+A/661/A8 : eFEDS catalogue of variable X-ray sources (Boller+, 2022)
J/A+A/661/A10 : eFEDS galaxy clusters and groups in disguise (Bulbul+, 2022)
J/A+A/661/A23 : Exoplanet X-ray irradiation & evaporation rates (Foster+, 2022)
J/A+A/661/A24 : Corona-chromosphere connection (Fuhrmeister+, 2022)
J/A+A/661/A29 : First eROSITA study of nearby M dwarfs (Magaudda+, 2022)
J/A+A/661/A34 : eta Cha cluster eROSITA X-ray scan (Robrade+, 2022)
J/A+A/661/A38 : SRG/ART-XC 1st year all-sky X-ray survey (Pavlinsky+, 2022)
J/A+A/661/A40 : eRASS1 X-ray sources Sco-Cen members (Schmitt+, 2022)
J/A+A/661/A44 : A first eROSITA view of ultracool dwarfs (Stelzer+, 2022)
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- No Sequential number
5- 26 A22 ---- eROSITA eROSITA SRC-Name (SRGJHHMMSS.ss+DDMMSS.s)
28- 29 I2 h RAh Right ascension (J2000)
31- 32 I2 min RAm Right ascension (J2000)
34- 38 F5.2 s RAs Right ascension (J2000)
40 A1 --- DE- Declination sign (J2000)
41- 42 I2 deg DEd Declination (J2000)
44- 45 I2 arcmin DEm Declination (J2000)
47- 50 F4.1 arcsec DEs Declination (J2000)
52- 56 F5.2 arcsec e_pos 1 sigma positional error of the source
58- 63 F6.2 10-17W/m2 FObs1 ?=- Flux in 0.2-5keV band for observation 1
65- 70 F6.2 10-17W/m2 e_FObs1 ? rms uncertainty on FObs1
72- 77 F6.2 10-17W/m2 FObs2 ?=- Flux in 0.2-5keV band for observation 2
79- 82 F4.2 10-17W/m2 e_FObs2 ? rms uncertainty on FObs2
84- 89 F6.2 10-17W/m2 FObs3 ?=- Flux in 0.2-5keV band for observation 3
91- 96 F6.2 10-17W/m2 e_FObs3 ? rms uncertainty on FObs3
98-103 F6.2 10-17W/m2 FObs4 ?=- Flux in 0.2-5keV band for observation 4
105-110 F6.2 10-17W/m2 e_FObs4 ? rms uncertainty on FObs4
113-118 F6.2 10-17W/m2 FObs5 ?=- Flux in 0.2-5keV band for observation 5
120-124 F5.2 10-17W/m2 e_FObs5 ? rms uncertainty on FObs5
126-130 F5.2 --- HR1 ?=- Harness ratio 1 (0.2-0.6keV, 0.6-1.1keV)
132-137 F6.2 --- e_HR1 ? rms uncertainty on HR1
139-143 F5.2 --- HR2 ?=- Harness ratio 2 (0.6-1.1keV, 1.1-2.3keV)
145-149 F5.2 --- e_HR2 ? rms uncertainty on HR2
151-155 F5.2 --- HR3 Harness ratio 3 (1.1-2.3keV, 2.3-5.0keV)
157-160 F4.2 --- e_HR3 rms uncertainty on HR3
162-166 F5.2 --- Var ?=- Variability of the source
168-173 F6.2 --- e_Var ? rms uncertainty on Var
175-179 A5 --- Class Classification (1)
181-185 A5 --- Cat [CalPV] CalPV: Source is in the eROSITA
CalPV catalogue as well
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Note (1): Classification as follows:
AB = active binary
AGN = Active galactic nuclei
CV = Cataclysmic variable
FG = Foreground star
SYM = Symbiotic star
QLMXB = Quiescent LMXB
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- No Sequential number
5- 9 F5.2 mag W1mag W1 magnitude of the infrared counterpart of
the X-ray source
11- 15 F5.2 mag e_W1mag rms uncertainty on W1mag
17- 21 F5.2 mag W2mag W2 magnitude of the infrared counterpart of
the X-ray source
23- 27 F5.2 mag e_W2mag rms uncertainty on W2mag
29 A1 --- l_W3mag Limit flag on W3
30- 34 F5.2 mag W3mag W3 magnitude of the infrared counterpart of
the X-ray source
36- 40 F5.2 mag e_W3mag ? rms uncertainty on W3mag
42 A1 --- l_W4mag Limit flag on W4mag
43- 47 F5.2 mag W4mag W4 magnitude of the infrared counterpart of
the X-ray source
49- 53 F5.2 mag e_W4mag ? rms uncertainty on W4mag
55- 59 F5.2 mag Jmag ?=- J magnitude of the infrared counterpart of
the X-ray source
61- 65 F5.2 mag e_Jmag ? rms uncertainty on Jmag
67- 71 F5.2 mag Hmag ?=- H magnitude of the infrared counterpart of
the X-ray source
73- 77 F5.2 mag e_Hmag ? rms uncertainty on Hmag
79- 83 F5.2 mag Ksmag ?=- Ks magnitude of the infrared counterpart
of the X-ray source
85- 89 F5.2 mag e_Ksmag ? rms uncertainty on Ksmag
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Byte-by-byte Description of file: tableb3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- No Sequential number
5- 10 F6.3 mag Gmag Gaia G (300nm) magnitude of
Gaia counterpart of the X-ray source
12- 17 F6.3 mag e_Gmag rms uncertainty on Gmag
20- 25 F6.3 mag BPmag ?=- Gaia BP (400-500nm) magnitude of
Gaia counterpart of the X-ray source
27- 32 F6.3 mag e_BPmag ? rms uncertainty on BPmag
34- 39 F6.3 mag RPmag ?=- Gaia RP (600-750nm) magnitude of
Gaia counterpart of the X-ray source
41- 46 F6.3 mag e_RPmag ? rms uncertainty on RPmag
48- 53 F6.3 mag gmag ?=- SkyMapper g (467nm) magnitude of
SkyMapper counterpart of the X-ray source
55- 60 F6.3 mag e_gmag ? rms uncertainty on gmag
62- 67 F6.3 mag rmag ?=- SkyMapper r (616nm) magnitude of
SkyMapper counterpart of the X-ray source
69- 74 F6.3 mag e_rmag ? rms uncertainty on rmag
76- 82 F7.3 pc Dist ? Gaia distance
84- 89 F6.3 pc e_Dist ? rms uncertainty on Gaia distance
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Acknowledgements:
Sara Saeedi, sara.saeedi(at)fau.de
References:
The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the
SRG mission, 2022, A&A, 661, A1-A46
(End) Patricia Vannier [CDS] 04-Feb-2022