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