J/A+A/490/113 X-ray sources in NGC 752 (Giardino+, 2008)
The X-ray luminosity of solar-mass stars in the intermediate age open cluster
NGC 752.
Giardino G., Pillitteri I., Favata F., Micela G.
<Astron. Astrophys. 490, 113 (2008)>
=2008A&A...490..113G 2008A&A...490..113G
ADC_Keywords: Clusters, open ; X-ray sources ; Photometry, infrared
Keywords: Galaxy: open clusters and associations: individual: NGC 752 -
stars: coronae - stars: activity - stars: rotation - X-rays: stars
Abstract:
While observational evidence shows that most of the decline in a
star's X-ray activity occurs between the age of the Hyades (∼8x10^8yr)
and that of the Sun, very little is known about the evolution of
stellar activity between these ages. To gain information on the
typical level of coronal activity at a star's intermediate age, we
studied the X-ray emission from stars in the 1.9Gyr old open cluster
NGC 752.
We analysed a ∼140ks Chandraobservation of NGC 752 and a ∼50ks
XMM-Newtonobservation of the same cluster. We detected 262 X-ray
sources in the Chandra data and 145 sources in the XMM-Newton
observation. Around 90% of the catalogued cluster members within
Chandra's field-of-view are detected in the X-ray. The X-ray
luminosity of all observed cluster members (28 stars) and of 11
cluster member candidates was derived.
Description:
Tables 6 and 7 provide the lists of X-ray sources detected in two
X-ray observations of the open cluster NGC 752: a ∼140ks Chandra
observation (Table 6) and a ∼50ks XMM-Newton observation (Table 7).
For the sources with a 2MASS counterpart the values of their
magnitudes in the J, H and K bands are also given. Additionally, in
Table 7, for the sources with a Chandra counterpart (within a search
radius of 5arcsec) the values of their Chandra ID (as per Table 6)
are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table6.dat 61 262 *X-ray sources detected with Pwdetect in the
Chandra observation of the open cluster NGC 752
(energy band ΔE=0.5-2.0keV)
table7.dat 69 145 *X-ray sources detected with Pwxdetect in the XMM
observation of the open cluster NGC 752.
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Note on table6.dat: For the sources with a 2MASS counterpart (within a
search radius of 3") the values of their magnitudes in the J, H and
K bands are also given, together with the radial distance from this
counterpart (r).
Note on table7.dat: For the sources with a Chandra counterpart (within a
search radius of 5") the values of their Chandra ID are given,
together with the radial distance from this counterpart (r(ID)).
For the sources with a 2MASS counterpart (within a search radius of
5") the values of their magnitudes in the J, H and K bands are also
given, together with the radial distance from the IR counterpart (r)
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See also:
J/PASP/106/281 : Photometry and radial velocities in NGC 752 (Daniel+, 1994)
J/A+AS/87/69 : Photometry and radial velocities in NGC 752 (Daniel+, 1994)
J/A+A/339/423 : Velocities of red giants in NGC 752 (Mermilliod+ 1998)
Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 14 F4.1 s RAs [0/60] Right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 24 I2 arcsec DEs [0/60] Declination (J2000)
26- 30 F5.2 ct/ks CR Count rate
32- 35 F4.2 ct/ks e_CR rms uncertainty on CR
38- 43 F6.3 mag Jmag ?=- 2MASS J magnitude
45- 50 F6.3 mag Hmag ?=- 2MASS H magnitude
52- 57 F6.3 mag Kmag ?=- 2MASS K magnitude
59- 61 F3.1 arcsec r ?=- Radial distance to the 2MASS counterpart
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
4 A1 --- n_Seq [±] Note on Seq (1)
6- 7 I2 h RAh Right ascension (J2000)
9- 10 I2 min RAm Right ascension (J2000)
12- 15 F4.1 s RAs [0/60] Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 25 I2 arcsec DEs [0/60] Declination (J2000)
27- 31 F5.2 ct/ks CR Count rate
33- 36 F4.2 ct/ks e_CR rms uncertainty on CR
38- 40 I3 --- ID ?=- Chandra Counterpart number
42- 44 F3.1 arcsec r(ID) ?=- Radial distance to the Chandra counterpart
46- 51 F6.3 mag Jmag ?=- 2MASS J magnitude
53- 58 F6.3 mag Hmag ?=- 2MASS H magnitude
60- 65 F6.3 mag Kmag ?=- 2MASS K magnitude
67- 69 F3.1 arcsec r ?=- Radial distance to the 2MASS counterpart
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Note (1): Note on Seq as follows:
+ = source could be spurious (detection scale of ∼2.8" is small for XMM)
- = corresponding Chandra source does not have 2MASS counterpart
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Acknowledgements:
G. Giardino, GGiardino(at)rssd.esa.int
(End) G. Giardino [ESA], Patricia Vannier [CDS] 02-Sep-2008