J/A+A/688/A224        Young stars in Dragonfish                 (Sanchez+, 2024)

Cloud structure and young star distribution in the Dragonfish complex. Sanchez N., Nespoli E., Gonzalez M., Climent J.B. <Astron. Astrophys. 688, A224 (2024)> =2024A&A...688A.224S 2024A&A...688A.224S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, early-type; Stellar distribution; YSOs ; Photometry, infrared Keywords: stars: early-type - stars: formation - ISM: clouds - ISM: structure - ISM: individual objects: Drangonfish Nebula Abstract: Star formation is a complex process involving several physical mechanisms that interact with each other at different spatial scales. One way to shed some light on the star formation process is to analyse the relationship between the spatial distributions of gas and newly formed stars. In order to obtain robust results, it is necessary for this comparison to be made using quantitative and consistent descriptors applied to the same star-forming region. We used fractal analysis to characterise and compare in a self-consistent way the structure of the cloud and the distribution of young stellar objects (YSO) in the Dragonfish star-forming complex. Different emission maps of the Dragonfish nebula were retrieved from the NASA/IPAC Infrared Science and the Planck Legacy archives. Moreover, we used photometric information from the AllWISE catalogue to select a total of 1082 YSOs in the region. We derived the physical properties for some of these from their spectral energy distributions (SEDs). For the cloud images and YSOs, the three-dimensional fractal dimension (Df) was calculated using previously developed and calibrated algorithms. The fractal dimension of the Dragonfish Nebula (Df=2.6-2.7) agrees very well with values previously obtained for the Orion, Ophiuchus, and Perseus clouds. On the other hand, YSOs exhibit on average a significantly smaller value (Df=1.9-2.0) that indicates a much more clumpy structure than the material from which they formed. This is a clear and direct evidence that the clustering degree of the newly born stars is significantly higher than that of the parent cloud from which they formed, but the physical mechanism behind this behaviour is still not clear. Additionally, younger Class I and Class II sources have smaller values (Df=1.7±0.1) than more evolved Transition Disk objects (Df=2.2±0.1), evidencing a certain evolutionary effect where an initially clumpy structure tends to gradually disappear over time. The structure of the Dragonfish complex is similar to that of other molecular clouds in the Galaxy. However, we found clear and direct evidence that the clustering degree of the newly born stars is significantly higher than that of the parent cloud from which they formed. The physical mechanism behind this behaviour is still not clear. Description: We study the distribution of YSOs in the Dragonfish region. The sample of YSOs were selected using photometric information from the AllWISE catalogue. This table contains the list of the 1082 selected YSOs and their derived properties. Objects: -------------------------------------------------------------- RA (2000) DE Designation(s) -------------------------------------------------------------- 12 11 27.48 -62 55 09.9 Dragonfish Nebula = GAL 298.4-00.4 -------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table2.dat 231 1082 List of YSOs and their properties -------------------------------------------------------------------------------- See also: II/328 : AllWISE Data Release (Cutri+ 2013) Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 19 A19 --- AllWISE ID from AllWISE 21- 33 F13.9 deg GLON Galactic longitude 35- 46 F12.9 deg GLAT Galactic latitude 48- 58 F11.7 deg RAdeg Right Ascension (J2000) 60- 70 F11.7 deg DEdeg Declination (J2000) 72- 77 F6.3 mag W1mag ? W1 band magnitude 79- 83 F5.3 mag e_W1mag ? Mean error on W1mag 85- 90 F6.3 mag W2mag ? W2 band magnitude 92- 96 F5.3 mag e_W2mag ? Mean error on W2mag 98-103 F6.3 mag W3mag ? W3 band magnitude 105-109 F5.3 mag e_W3mag ? Mean error on W3mag 111-116 F6.3 mag W4mag ? W4 band magnitude 118-122 F5.3 mag e_W4mag ? Mean error on W4mag 124-129 F6.3 mag Jmag ? J band magnitude 131-135 F5.3 mag e_Jmag ? Mean error on Jmag 137-142 F6.3 mag Hmag ? H band magnitude 144-148 F5.3 mag e_Hmag ? Mean error on Hmag 150-155 F6.3 mag Kmag ? K band magnitude 157-161 F5.3 mag e_Kmag ? Mean error on Kmag 163-170 A8 --- Class Object class (1) 172-188 A17 --- REF References for previously identified YSOs (2) 190-192 A3 --- Cluster Substructure ID 194-201 A8 --- Modelfit Best model used for SED fitting 203-208 F6.1 K Teff ? Effective temperature from SED fitting 210-212 F3.1 mag Av ? Visual extinction from SED fitting 214-216 F3.1 [cm/s2] logg ? Surface gravity from SED fitting 218-224 F7.4 mas Plx ? Gaia parallax 226-231 F6.4 mas e_Plx ? Error on Plx -------------------------------------------------------------------------------- Note (1): Class according to selection criteria defined in Koenig and Leisawitz (2014ApJ...791..131K 2014ApJ...791..131K) as follows: Class I = Class I YSO Class II = Class II YSO TrDisk = Transition disk Note (2): References as follows: Kuh21 = Kuhn et al., 2021ApJS..254...33K 2021ApJS..254...33K, Cat. J/ApJS/254/33 Lum13 = Lumsden et al., 2013ApJS..208...11L 2013ApJS..208...11L, Cat. J/ApJS/208/11 Mar16 = Marton et al., 2016MNRAS.458.3479M 2016MNRAS.458.3479M, Cat. J/MNRAS/458/3479 Rim23 = Rimoldini et al., 2023A&A...674A..14R 2023A&A...674A..14R Zha23 = Zhang et al., 2023ApJS..264...24Z 2023ApJS..264...24Z, Cat. J/ApJS/264/24 -------------------------------------------------------------------------------- Acknowledgements: Nestor Sanchez, nessandor(at)gmail.com History: 26-Aug-2024: on-line version 11-Oct-2024: declination corrected (minus sign was missing)
(End) Patricia Vannier [CDS] 10-Jul-2024
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