Abstract
We present the results from our deep optical photometric observations of Bochum 2 (Boc2) star cluster obtained using the 1.3-m Devasthal Fast Optical Telescope along with archival photometric data from Pan-STARRS2/2MASS/UKIDSS surveys. We also used high-quality parallax and proper motion data from the Gaia Data Release 3. We found that the Boc2 cluster has a small size (\(\sim \)1.1 pc) and circular morphology. Using Gaia parallax of member stars and isochrone fitting method, the distance of this cluster is estimated as \(3.8\pm 0.4\) kpc. We have found that this cluster holds young (\({\sim }5\) Myr) and massive (O7–O9) stars as well as an older population of low mass stars. We found that the massive stars were formed in the inner region of the Boc2 cluster in a recent epoch of star formation. We have derived mass function slope (\(\Gamma \)) in the cluster region as \(-2.42\pm 0.13\) in the mass range of \({\sim }0.72<M/M_{\odot }<2.8\). The tidal radius of the Boc2 cluster (\(\sim \)7–9) is much more than its observed radius (\({\sim }1.1\) pc). This suggests that most of the low-mass stars in this cluster are the remains of an older population of stars formed via an earlier epoch of star formation.
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Notes
IRAF is distributed by National Optical Astronomy Observatories, USA.
ESO-MIDAS is developed and maintained by the European Southern Observatory.
References
Allison R. J., Goodwin S. P., Parker R. J. et al. 2009, MNRAS, 395, 1449
Bailer-Jones C. A. L., Rybizki J., Fouesneau M., Demleitner M., Andrae R. 2021, AJ, 161, 147
Balaguer-Núnez L., Tian K. P., Zhao J. L. 1998, A &AS, 133, 387
Binney J., Tremaine S. 1987, Galactic dynamics
Bisht D., Yadav R. K. S., Durgapal A. K. 2017, New A, 52, 55
Bovy J. 2017, MNRAS, 468, L63
Camargo D., Bonatto C., Bica E. 2015, MNRAS, 450, 4150
Chabrier G. 2003, PASP, 115, 763
Chambers K. C., Magnier E. A., Metcalfe N. et al. 2016, arXiv e-prints, 1612.05560
Chauhan N., Pandey A. K., Ogura K. et al. 2011, MNRAS, 415, 1202
Cutri R. M., Skrutskie M. F., van Dyk S. et al. 2003, VizieR Online Data Catalog, II/246
Dalessandro E., Ferraro F. R., Massari D. et al. 2015, ApJ, 810, 40
Dib S., Schmeja S., Parker R. J. 2018, MNRAS, 473, 849
Gaia Collaboration, Prusti T., de Bruijne J. H. J. et al. 2016, A &A, 595, A1
Gaia Collaboration, Katz D., Antoja T. et al. 2018a, A &A, 616, A11
Gaia Collaboration, Brown A. G. A., Vallenari A. et al. 2018b, A &A, 616, A1
Gieles M., Baumgardt H. 2008, MNRAS, 389, L28
Gieles M., Portegies Zwart S. F., Baumgardt H. et al. 2006, MNRAS, 371, 793
Girard T. M., Grundy W. M., Lopez C. E., van Altena W. F. 1989, AJ, 98, 227
Gutermuth R. A., Megeath S. T., Myers P. C. et al. 2009, ApJS, 184, 18
Gutermuth R. A., Megeath S. T., Pipher J. L. et al. 2005, ApJ, 632, 397
Jose J., Herczeg G. J., Samal M. R., Fang Q., Panwar N. 2017, ApJ, 836, 98
Jose J., Pandey A. K., Ojha D. K. et al. 2008, MNRAS, 384, 1675
Jose J., Pandey A. K., Samal M. R. et al. 2013, MNRAS, 432, 3445
Kaur H., Sharma S., Dewangan L. K. et al. 2020, ApJ, 896, 29
Kharchenko N. V., Piskunov A. E., Schilbach E., Röser S., Scholz R. D. 2016, A &A, 585, A101
Kroupa P., Boily C. M. 2002, MNRAS, 336, 1188
Lada C. J., Muench A. A., Luhman K. L. et al. 2006, AJ, 131, 1574
Landolt A. U. 1992, AJ, 104, 340
Lawrence A., Warren S. J., Almaini O. et al. 2007, MNRAS, 379, 1599
Luhman K. L., Esplin T. L., Loutrel N. P. 2016, ApJ, 827, 52
Moffat A. F. J., Fitzgerald M. P., Jackson P. D. 1979, A &AS, 38, 197
Moffat A. F. J., Vogt N. 1975, A &AS, 20, 85
Munari U., Carraro G. 1995, MNRAS, 277, 1269
Olczak C., Spurzem R., Henning T. 2011, A &A, 532, A119
Pandey A. K., Sharma S., Ogura K. et al. 2008, MNRAS, 383, 1241
Pandey A. K., Upadhyay K., Ogura K. et al. 2005, MNRAS, 358, 1290
Pandey A. K., Eswaraiah C., Sharma S. et al. 2013, ApJ, 764, 172
Pandey R., Sharma S., Panwar N. et al. 2020, ApJ, 891, 8
Pandey R., Sharma S., Dewangan L. K. et al. 2022, ApJ, 926, 25
Pastorelli G., Marigo P., Girardi L. et al. 2019, MNRAS, 485, 5666
Pecaut M. J., Mamajek E. E. 2013, ApJS, 208, 9
Pflamm-Altenburg J., Kroupa P. 2009, MNRAS, 397, 488
Phelps R. L., Janes K. A. 1994, ApJS, 90, 31
Pinfield D. J., Jameson R. F., Hodgkin S. T. 1998, MNRAS, 299, 955
Roeser S., Demleitner M., Schilbach E. 2010, AJ, 139, 2440
Russeil D., Adami C., Georgelin Y. M. 2007, A &A, 470, 161
Salpeter E. E. 1955, ApJ, 121, 161
Sharma S., Pandey A. K., Ogura K. et al. 2006, AJ, 132, 1669
Sharma S., Pandey A. K., Ogura K. et al. 2008, AJ, 135, 1934
Sharma S., Pandey A. K., Ojha D. K. et al. 2007, MNRAS, 380, 1141
Sharma S., Pandey A. K., Ojha D. K. et al. 2017, MNRAS, 467, 2943
Sharma S., Pandey A. K., Pandey J. C. et al. 2012, PASJ, 64, 107
Sharma S., Ghosh A., Ojha D. K. et al. 2020, MNRAS, 498, 2309
Skrutskie M. F., Cutri R. M., Stiening R. et al. 2006, AJ, 131, 1163
Stetson P. B. 1987, PASP, 99, 191
Stetson P. B. 1992, in Astronomical Society of the Pacific Conference Series, Vol. 25, Astronomical Data Analysis Software and Systems I, eds Worrall D. M., Biemesderfer C., Barnes J., p. 297
Turbide L., Moffat A. F. J. 1993, AJ, 105, 1831
Yadav R. K. S., Sariya D. P., Sagar R. 2013, MNRAS, 430, 3350
Yeh F.-C., Carraro G., Korchagin V. I., Pianta C., Ortolani S. 2020, A &A, 635, A125
Acknowledgements
The observations reported in this paper were obtained using the 1.3m Devesthal Fast Optical Telescope, Nainital, India. This work is based on data obtained as part of the UKIRT Infrared Deep Sky Survey (UKIDSS). This publication made use of data products from 2MASS (a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and NSF) and archival data obtained with the Spitzer Space Telescope (operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA). This study has made use of data from the European Space Agency (ESA) mission Gaia (https://cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC; https://cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by the institutions participating in the Gaia Multilateral Agreement.
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This article is part of the Special Issue on “Star formation studies in the context of NIR instruments on 3.6 m DOT”.
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Kaur, H., Sharma, S., Durgapal, A. et al. Structural analysis of open cluster Bochum 2. J Astrophys Astron 44, 66 (2023). https://doi.org/10.1007/s12036-023-09953-9
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DOI: https://doi.org/10.1007/s12036-023-09953-9