J/MNRAS/498/2309 The disintegrating old open cluster Czernik 3 (Sharma+, 2020)
The disintegrating old open cluster Czernik 3.
Sharma S., Ghosh A., Ojha D.K., Pandey R., Sinha T., Pandey A.K.,
Ghosh S.K., Panwar N., Pandey S.B.
<Mon. Not. R. Astron. Soc., 498, 2309-2322 (2020)>
=2020MNRAS.498.2309S 2020MNRAS.498.2309S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Populations, stellar ; Positional data ;
Parallaxes, trigonometric ; Proper motions ; Photometry ;
Optical ; Infrared
Keywords: stars: kinematics and dynamics -
stars: luminosity function, mass function -
open clusters and associations: individual: Czernik 3
Abstract:
We have performed a detailed analysis of the Czernik 3 (Cz3) open
cluster by using deep near-infrared photometry taken with TIRCAM2 on
the 3.6m Devasthal optical telescope along with the recently available
high-quality proper motion data from the Gaia DR2 and deep photometric
data from Pan-STARRS1. The cluster has a highly elongated morphology
with fractal distribution of stars. The core and cluster radii of the
cluster are estimated as 0.5 and 1.2pc, respectively. We have
identified 45 stars as cluster members using the Gaia proper motion
data. The distance and age of the cluster are found to be 3.5±0.9kpc
and 0.9+0.3-0.1Gyr, respectively. The slope of the mass function
'Γ' in the cluster region, in the mass range
∼0.95<M/M☉<2.2, is found to be -1.01±0.43. The cluster shows
the signatures of mass segregation and is dynamically relaxed
(dynamical age = 10Myr). This along with its small size, big tidal
radius, low density/large separation of stars, and elongated and
distorted morphology indicates that the Cz3 is a loosely bound
disintegrating cluster under the influence of external tidal
interactions.
Description:
Deep NIR J (1.20µm), H (1.65µm), and K (2.19µm) band
photometric observations of the Cz3 open cluster were taken during the
night of 2017 October 7 using TIFR Near Infrared Imaging Camera-II
(TIRCAM2; Naik et al. 2012BASI...40..531N 2012BASI...40..531N; Baug et al.
2018JAI.....750003B) mounted at the Cassegrain main port of the 3.6m
ARIES Devasthal optical telescope (DOT; Kumar et al.
2018BSRSL..87...29K 2018BSRSL..87...29K). The weather conditions in these nights were good
with a relative humidity of <60 per cent and the full width at
half-maximum of the stellar images was ∼0.6arcsec. The field of view
(FOV) of the TIRCAM2 is ∼86.5x86.5arcsec square with a plate scale of
0.169arcsec. We took four pointings of the Cz3 open cluster covering
the central cluster region (∼3arcmin square) and in each pointing
several frames in a five-point dither pattern were taken with exposure
times of 50, 50, and 10 s in the J, H, and K bands, respectively. The
total exposure times were 500, 500, and 1000s in each pointing in the
J, H, and K bands, respectively. Dark and sky flats were also taken
during the observations. Sky frames in each filter were generated from
the median of the dithered frames.
In order to study a wider area around Cz3, we have selected an FOV of
10x10arcmin square and downloaded the available data from Gaia DR2
(Gaia Collaboration 2018A&A...616A...1G 2018A&A...616A...1G, Cat. I/345), Pan-STARRS1
(Chambers et al. 2016arXiv161205560C 2016arXiv161205560C, Cat. II/349) and 2MASS (Cutri et
al. 2003yCat.2246....0C 2003yCat.2246....0C, Cat. II/246).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 151 Sample of the NIR photometry of the stars in
this study
table3.dat 78 45 Sample of 45 stars identified as cluster members
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/151] Internal object identifier
5- 13 F9.6 deg RAdeg Right ascension (J2000)
15- 24 F10.6 deg DEdeg Declination (J2000)
26- 31 F6.3 mag Jmag J-band magnitude
33- 37 F5.3 mag e_Jmag Error on Jmag
39- 44 F6.3 mag Hmag H-band magnitude
46- 50 F5.3 mag e_Hmag Error on Hmag
52- 57 F6.3 mag Kmag K-band magnitude
59- 63 F5.3 mag e_Kmag Error on Kmag
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- ID [1/45] Internal object identifier
4- 12 F9.6 deg RAdeg Right ascension (J2000)
14- 22 F9.6 deg DEdeg Declination (J2000)
24- 29 F6.3 mas plx Parallax
31- 35 F5.3 mas e_plx Error on plx
37- 42 F6.3 mas/yr pmRA Proper motion in right ascension
44- 48 F5.3 mas/yr e_pmRA Error on pmRA
50- 55 F6.3 mas/yr pmDE Proper motion in declination
57- 61 F5.3 mas/yr e_pmDE Error on pmDE
63- 68 F6.3 mag Gmag G-band magnitude from Gaia DR2
70- 74 F5.3 mag BP-RP ? BP-RP colour from Gaia DR2
76- 78 I3 % Prob Membership probability
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 03-Aug-2023