Browse > Article
http://dx.doi.org/10.5303/JKAS.2015.48.6.343

SEJONG OPEN CLUSTER SURVEY (SOS) - V. THE ACTIVE STAR FORMING REGION SH 2-255 - 257  

LIM, BEOMDU (Korea Astronomy and Space Science Institute)
SUNG, HWANKYUNG (Department of Astronomy and Space Science, Sejong University)
HUR, HYEONOH (Department of Astronomy and Space Science, Sejong University)
LEE, BYEONG-CHEOL (Korea Astronomy and Space Science Institute)
BESSELL, MICHAEL S. (Research School of Astronomy and Astrophysics, Australian National University, MSO)
KIM, JINYOUNG S. (Steward Observatory, University of Arizona)
LEE, KANG HWAN (Gwacheon National Science Museum)
PARK, BYEONG-GON (Korea Astronomy and Space Science Institute)
JEONG, GWANGHUI (Korea Astronomy and Space Science Institute)
Publication Information
Journal of The Korean Astronomical Society / v.48, no.6, 2015 , pp. 343-355 More about this Journal
Abstract
There is much observational evidence that active star formation is taking place in the Hii regions Sh 2-255 – 257. We present a photometric study of this star forming region (SFR) using imaging data obtained in passbands from the optical to the mid-infrared, in order to study the star formation process. A total of 218 members were identified using various selection criteria based on their observational properties. The SFR is reddened by at least E(B −V ) = 0.8 mag, and the reddening law toward the region is normal (RV = 3.1). From the zero-age main sequence fitting method it is confirmed that the SFR is 2.1 ± 0.3 kpc from the Sun. The median age of the identified members is estimated to be about 1.3 Myr from a comparison of the Hertzsprung-Russell diagram (HRD) with stellar evolutionary models. The initial mass function (IMF) is derived from the HRD and the near-infrared (J, J −H) color-magnitude diagram. The slope of the IMF is about Γ = −1.6 ± 0.1, which is slightly steeper than that of the Salpeter/Kroupa IMF. It implies that low-mass star formation is dominant in the SFR. The sum of the masses of all the identified members provides the lower limit of the cluster mass (169M⊙). We also analyzed the spectral energy distribution (SED) of pre-main sequence stars using the SED fitting tool of Robitaille et al., and confirm that there is a significant discrepancy between stellar mass and age obtained from two different methods based on the SED fitting tool and the HRD.
Keywords
open clusters and associations; individual; Sh 2-255 - 257 (IC 2162) - dust, extinction - stars; luminosity function, mass function;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Armandroff, T. E., & Herbst, W. 1981, Distances to 14 Molecular Clouds (Including Two Associated with Supernova Remnants) by a New Technique, AJ, 86, 1923   DOI
2 Beichman, C. A., Becklin, E. E., & Wynn-Williams, C. G. 1979, New Multiple Systems in Molecular Clouds, ApJ, 232, 47   DOI
3 Bell, C. P. M., Naylor, T., Mayne, N. J., Jeffries, R. D., & Littlefair, S. P. 2013, Pre-Main-Sequence Isochrones - II. Revisiting Star and Planet Formation Time-Scales, MNRAS, 434, 806   DOI
4 Bessell, M. S. 1995, The Temperature Scale for Cool Dwarfs, in Proc. ESO Workshop, The Bottom of the Main Sequence and Beyond, ed. C. G. Tinney (Berlin: Springer), 123
5 Bessell, M. S., Castelli, F., & Plez, B. 1998, Model Atmospheres Broad-Band Colors, Bolometric Corrections and Temperature Calibrations for O - M Stars, A&A, 333, 231
6 Bieging, J. H., Peters, W. L., Vilaro, B. V., Schlottman, K., & Kulesa, C. 2009, Sequential Star Formation in the Sh 254-258 Molecular Cloud: Heinrich Hertz Telescope Maps of CO J = 2 − 1 and 3 − 2 Emission, AJ, 138, 975   DOI
7 Blair, G. N., Peters, W. L., & vanden Bout, P. A. 1975, Strong Molecular Line Emission Associated with Small Halpha Emission Regions, ApJ, 200, L161   DOI
8 Broos, P. B., Getman, K. V., Povich, M. S., Townsley, L. K., Feigelson, E. D., & Garmire, G. P. 2011, A Naive Bayes Source Classifier for X-Ray Sources, ApJS, 194, 4   DOI
9 Caramazza, M., Micela, G., Prisinzano, L., Sciortino, S., Damiani, F., Favata, F., Stauffer, J. R., Vallenari, A., & Wolk, S. J. 2012, Star Formation in the Outer Galaxy: Coronal Properties of NGC 1893, A&A, 539, 74   DOI
10 Chavarría, L. A., Allen, L. E., Hora, J. L., Brunt, C. M., & Fazio, G. G. 2008, Spitzer Observations of the Massive Star-Forming Complex S254-S258: Structure and Evolution, ApJ, 682, 445   DOI
11 Chavarría-K, C., de Lara, E., & Hasse, I. 1987, Eight-Colour Photometry of Stars Associated with Selected Sharpless H II Regions at L exp II of about 190 deg - S 252, S 254, S 255, S 257, and S 261, A&A, 171, 216
12 Draine, B. T. 2003, Interstellar Dust Grains, ARA&A, 41, 241   DOI
13 Ekström, S., Georgy, C., Eggenberger, P., et al. 2012, Grids of Stellar Models with Rotation. I. Models from 0.8 to 120 M⊙ at Solar Metallicity (Z = 0.014), A&A, 537, 146   DOI
14 Elmegreen B. G., & Lada C. J. 1977, Sequential Formation of Subgroups in OB Associations, ApJ, 214, 725   DOI
15 Evans, N. J., II., Beckwith, S., & Blair, G. N. 1977, The Energetics of Molecular Clouds. I - Methods of Analysis and Application to the S255 Molecular Cloud, ApJ, 217, 448   DOI
16 Fitzpatrick, E. L., & Massa, D. 2007, An Analysis of the Shapes of Interstellar Extinction Curve. V. The IRThrough-UV Curve Morphology, ApJ, 663, 320   DOI
17 Flaccomio, E., Micela, G., Sciortino, S., Favata, F., Corbally, C., & Tomaney, A. 1999, BV RI photometry of the Star-Forming Region NGC 2264: the Initial Mass Function and Star-Forming Rate, A&A, 345, 521
18 Goddi, C., Moscadelli, L., Sanna, A., Cesaroni, R., & Minier, V. 2007, Associations of H2O and CH3OH Masers at Milli-Arcsec Angular Resolution in Two High-Mass YSOs, A&A, 461, 1027   DOI
19 Georgelin, Y. M., Georgelin, Y. P., & Roux, S. 1973, Observations de nouvelles régions H II galactiques et d’étoiles excitatrices, A&A, 25, 337
20 Getman, K. V., Broos, P. S., Feigelson, E. D., Townsley, L. K., Povich, M. S., Garmire, G. P., Montmerle, T., Yonekura, Y., & Fukui, Y. 2011, Source Contamination in X-Ray Studies of Star-Forming Regions: Application to the Chandra Carina Complex Project, ApJS, 194, 3   DOI
21 Greve A. 2010, Extinction AV , R towards Emission Nebulae Derived from Common upper Level Paschen-Balmer Hydrogen Lines, A&A, 518, 62   DOI
22 Guetter, H. H., & Vrba, F. J. 1989, Reddening and Polarimetric Studies toward IC 1805, AJ, 98, 611   DOI
23 Howard, E. M., Pipher, J. L., & Forrest, W. J. 1997, S255-2: The Formation of a Stellar Cluster, ApJ, 481, 327   DOI
24 Hunter, D. A., & Massey, P. 1990, Small Galactic H II Regions. I - Spectral Classifications of Massive Stars, AJ, 99, 846   DOI
25 Hur, H., Park, B.-G., Sung, H., Bessell, M. S., Lim, B., Chun, M.-Y., & Sohn, S. T. 2015, Reddening, Distance, and Stellar Content of the Young Open Cluster Westerlund 2, MNRAS, 446, 3797   DOI
26 Hur, H., Sung, H., & Bessell, M. S. 2012, Distance and the Initial Mass Function of Young Open Clusters in the η Carina Nebula: Tr 14 and Tr 16, AJ, 143, 41   DOI
27 Kroupa, P. 2001, On the Variation of the Initial Mass Function, MNRAS, 322, 231   DOI
28 Jaffe, D. T., Davidson, J. A., Dragovan, M., & Hildebrand, R. H. 1984, Far-Infrared and Submillimeter Observations of the Multiple Cores in S255,W3, and OMC-1 - Evidence for Fragmentation?, ApJ, 284, 637   DOI
29 Kim, H., Nakajima, Y., Sung, H., Moon, D.-S., & Koo, B.-C. 2007, A near-Infrared Study of the Highly-Obscured Active Star-Forming Region W51B, JKAS, 40, 17
30 Kim, K.-M., Han, I., Valyavin, G. G., et al. 2007, The BOES Spectropolarimeter for Zeeman Measurements of Stellar Magnetic Fields, PASP, 119, 1052   DOI
31 Lada, C., & Lada, E. 2003, Embedded Clusters in Molecular Clouds, ARA&A, 41, 57   DOI
32 Lada, C. J., Muench, A. A., Haisch K. E., Jr., Lada, E. A., Alves, J. F., Tollestrup, E. V., & Willner, S. P. 2000, Infrared L-Band Observations of the Trapezium Cluster: A Census of Circumstellar Disks and Candidate Protostars, AJ, 120, 3162   DOI
33 Landolt, A. U. 1992, UBV RI Photometric Standard Stars in the Magnitude Range 11.5-16.0 around the Celestial Equator, AJ, 104, 340   DOI
34 Lefloch B., & Lazareff, B. 1994, Cometary Globules. 1: Formation, Evolution and Morphology, A&A, 289, 559
35 Lim, B., Chun, M.-Y., Sung, H., Park, B.-G., Lee, J.-J., Shon, S. T., Hur, H., & Bessell, M. S. 2013, The Starburst Cluster Westerlund 1: The Initial Mass Function and Mass Segregation, AJ, 145, 46   DOI
36 Lim, B., Sung, H., Bessell, M. S., Kim, J. S., Hur, H., & Park, B.-G. 2015, Sejong Open Cluster Survey (SOS) - IV. The Young Open Clusters NGC 1624 and NGC 1931, AJ, 149, 127   DOI
37 Lo, K. Y., & Burke, B. F. 1973, H2O Sources in Sharpless H II Regions, A&A, 26, 487
38 Lim, B., Sung, H., Karimov, R., & Ibrahimov, M. 2011, Sejong Open Cluster Survey. I. NGC 2353, JKAS, 44, 39   DOI
39 Lim, B., Sung, H., Kim, J. S., Bessell, M. S., & Karimov, R., 2014a, Sejong Open Cluster Survey (SOS) - II. IC 1848 Cluster in the H II Region W5 West, MNRAS, 438, 1451   DOI
40 Lim, B., Sung, H., Kim, J. S., Bessell, M. S., & Park, B.-G. 2014b, Sejong Open Cluster Survey (SOS) - III. The Young Open Cluster NGC 1893 in the H II Region W8, MNRAS, 443, 454   DOI
41 Menzies, J. W., Marang, F., Laing, J. D., Coulson, I. M., & Engelbrecht, C. A. 1991, UBV(RI)c Photometry of Equatorial Standard Stars - A Direct Comparison between the Northern and Southern Systems, MNRAS, 248, 642   DOI
42 Minier, V., Burton, M. G., Hill, T., Pestalozzi, M. R., Purcell, C. R., Garay, G., Walsh, A. J., & Longmore, S. 2005, Star-Forming Protoclusters Associated with Methanol Masers, A&A, 429, 945   DOI
43 Minier, V., Peretto, N., Longmore, S. N., Burton, M. G., Cesaroni, R., Goddi, C., Pestalozzi, M. R., & André, P. 2007, Anatomy of the S255S257 Complex Triggered High-Mass Star Formation, in Proc. IAU Symp. 237, Triggered Star Formation in a Turbulent ISM, ed. B. Elmegreen & J. Palous (Cambridge: Cambridge Univ. Press), 160
44 Moffat, A. F. J., Jackson, P. D., & Fitzgerald, M. P. 1979, The Rotation and Structure of the Galaxy beyond the Solar Circle. I - Photometry and Spectroscopy of 276 Stars in 45 H II Regions and Other Young Stellar Groups toward the Galactic Anticentre, A&AS, 38, 197
45 Morris, M., Palmer, P., Turner, B. E., & Zuckerman, B. 1974, Millimeter-Wavelength Molecular Lines and Far-Infrared Sources, ApJ, 191, 349   DOI
46 Pismis, P., & Hasse, I. 1976, Study of a Triple Emission Nebula in Orion, Ap&SS, 45, 79   DOI
47 Mucciarelli, P., Preibisch, T., & Zinnecker, H. 2011, Revealing the “Missing” Low-Mass Stars in the S254-S258 Star Forming Region by Deep X-Ray Imaging, A&A, 533, 121   DOI
48 Park, B.-G., & Sung, H. 2002, UBV I and Hα Photometry of the Young Open Cluster NGC 2244, AJ, 123, 892   DOI
49 Park, B.-G., Sung, H., Bessell, M. S., & Kang, Y. H. 2000, The Pre-Main-Sequence Stars and Initial Mass Function of NGC 2264, AJ, 120, 894   DOI
50 Porras, A., Christopher, M., Allen, L., et al. 2003, A Catalog of Young Stellar Groups and Clusters within 1 kiloparsec of the Sun, AJ, 126, 1916   DOI
51 Robitaille, T. P., Whitney, B. A., Indebetouw, R., & Wood, K. 2007, Interpreting Spectral Energy Distributions from Young Stellar Objects. II. Fitting Observed SEDs Using a Large Grid of Precomputed Models, ApJS, 169, 328   DOI
52 Russeil, D., Adami, C., & Georgelin, Y. M. 2007, Revised Distances of Northern HII Regions, A&A, 470, 161   DOI
53 Salpeter, E. E. 1955, The Luminosity Function and Stellar Evolution, ApJ, 121, 161   DOI
54 Sharpless, S. 1959, A Catalogue of H II Regions, ApJS, 4, 257   DOI
55 Siess, L., Dufour, E., & Forestini, M. 2000, An Internet Server for Pre-Main Sequence Tracks of Low- and Intermediate-Mass Stars, A&A, 358, 593
56 Skrutskie, M. F., et al. 2006, The Two Micron All Sky Survey (2MASS), AJ, 131, 1163   DOI
57 Sung, H., & Bessell, M. S. 2014, The Interstellar Reddening Law within 3kpc from the Sun, in ASP Conf. Ser. 482, the 10th Pacific Rim Conference on Stellar Astrophysics, ed. H.-W. Lee, Young Woon Kang, and Kam-Ching Leung (San Francisco, CA: ASP), 275
58 Sota, A., Maíz, A. J., Walborn, N. R., Alfaro, E. J., Barbá, R. H., Morrell, N. I., Gamen, R. C., & Arias, J. I. 2011, The Galactic O-Star Spectroscopic Survey. I. Classification System and Bright Northern Stars in the Blue-Violet at R ∼ 2500, ApJS, 193, 24   DOI
59 Sung, H., & Bessell, M. S. 2004, The Initial Mass Function and Stellar Content of NGC 3603, AJ, 127, 1014   DOI
60 Sung, H., & Bessell, M. S. 2010, The Initial Mass Function and Young Brown Dwarf Candidates in NGC 2264 IV. The Initial Mass Function and Star Formation History, AJ, 140, 2070   DOI
61 Sung, H., Bessell, M. S., & Chun, M.-Y. 2004, The Initial Mass Function and Young Brown Dwarf Candidates in NGC 2264. I. The Initial Mass Function around S Monocerotis, AJ, 128, 1684   DOI
62 Sung, H., Bessell, M. S., Chun, M.-Y., Karimov, R., & Ibrahimov, M. 2008, The Initial Mass Function and Young Brown Dwarf Candidates in NGC 2264 III. Photometric Data, AJ, 135, 441   DOI
63 Sung, H., Bessell M. S., & Lee, S.-W. 1997, UBV RI Hα Photometry of the Young Open Cluster NGC 2264, AJ, 114, 2644   DOI
64 Sung, H., Bessell, M. S., & Lee, S.-W. 1998, UBV RI and Hα Photometry of the Young Open Cluster NGC 6231, AJ, 115, 734   DOI
65 Sung, H., Chun, M.-Y., & Bessell, M. S. 2000, UBV RI and Hα Photometry of the Young Open Cluster NGC 6530, AJ, 120, 333   DOI
66 Turner, B. E. 1971, Anomalous OH Emission from New types of Galactic Objects, Astrophys. Lett., 8, 73
67 Sung, H., Lim, B., Bessell, M. S., Kim, J. S., Hur, H., Chun, M.-Y., & Park, B.-G. 2013a, Sejong Open Cluster Survey (SOS). 0. Target Selection and Data Analysis, JKAS, 46, 103
68 Sung, H., Sana, H., & Bessell, M. S. 2013b, The Initial Mass Function and the Surface Density Profile of NGC 6231, AJ, 145, 37   DOI
69 Sung, H., Stauffer, J. R., & Bessell, M. S. 2009, A Spitzer View of the Young Open Cluster NGC 2264, AJ, 138, 1116   DOI
70 Walborn, N. R. 1971, Some Spectroscopic Characteristics of OB Stars: an Investigation of the Space Distribution of Certain OB Stars and the Reference Frame of the Classification, ApJS, 23, 257   DOI
71 Walborn, N. R., & Fitzpatrick, E. L. 1990, Contemporary Optical Spectral Classification of the OB Stars - A Digital Atlas, PASP, 102, 379   DOI
72 Wang, Y., Beuther, H., Bik, A., Vasyunina, T., Jiang, Z., Puga, E., Linz, H., Rodón, J. A., Henning, T., & Tamura, M. 2011, Different Evolutionary Stages in the Massive Star-Forming Region S255 Complex, A&A, 527, 32   DOI
73 Whittet, D. C. B. 1977, The Dependence of the Extinction Ratio on Galactic Longitude, MNRAS, 180, 29   DOI
74 Zinchenko, I., Liu, S.-Y., Su, Y.-N., Kurtz, S., Ojha, D. K., Samal, M. R., & Ghosh, S. K. 2012, A multi-Wavelength High-Resolution Study of the S255 Star-Forming Region: General Structure and Kinematics, 755, 177   DOI