J/A+A/668/A19 Stellar population of Rosette Nebula and NGC 2244 (Muzic+, 2022)
Stellar population of the Rosette Nebula and NGC 2244.
Application of the probabilistic random fores.
Muzic K., Almendros-Abad V., Bouy H., Kubiak K., Pena Ramirez K.,
Krone-Martins A., Moitinho A., Conceicao M.
<Astron. Astrophys. 668, A19 (2022)>
=2022A&A...668A..19M 2022A&A...668A..19M (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Equivalent widths ; Extinction ; Spectral types;
Photometry, SDSS ; Photometry, infrared ; Photometry, H-alpha
Keywords: stars: pre-main sequence - stars: kinematics and dynamics -
open clusters and associations: individual: NGC 2244 -
open clusters and associations: individual: NGC 2237
Abstract:
Measurements of internal dynamics of young clusters and star-forming
regions are crucial to fully understand the process of their
formation. A basic prerequisite for this is a well-established and
robust list of probable members.
In this work, we study the 2.8degx2.6deg region in the emblematic
Rosette Nebula, centred in the young cluster NGC 2244, with the aim of
constructing the most reliable candidate member list to date. Using
the obtained catalogue, we can determine various structural and
kinematic parameters, which can help to draw conclusions about the
past and the future of the region.
We constructed a catalogue containing optical to mid-infrared
photometry, as well as accurate positions and proper motions from Gaia
EDR3 for the sources in the field of the Rosette Nebula. We applied
the probabilistic random forest algorithm to derive membership
probability for each source within our field of view. Based on the
list of almost 3000 probable members, of which about a third are
concentrated within the radius of 20' from the centre of NGC 2244,
we identified various clustered sources and stellar concentrations in
the region, and estimated the average distance to the entire region at
1489±37pc, 1440±32pc to NGC 2244, and 1525±36pc to NGC 2237. The
masses, extinction, and ages were derived by fitting the spectral
energy distribution to the atmosphere and evolutionary models, and the
internal dynamics was assessed via proper motions relative to the mean
proper motion of NGC 2244.
NGC 2244 is showing a clear expansion pattern, with an expansion
velocity that increases with radius. Its initial mass function (IMF)
is well represented by two power laws (dN/dM ∝ M-alpha),
with slopes alpha=1.05±0.02 for the mass range 0.2-1.5M☉ and
alpha = 2.3±0.3 for the mass range 1.5-20M☉ and is in
agreement with slopes detected in other star-forming regions. The mean
age of the region, derived from the HR diagram, is ∼ 2 Myr. We find
evidence for the difference in ages between NGC 2244 and the region
associated with the molecular cloud, which appears slightly younger.
The velocity dispersion of NGC 2244 is well above the virial velocity
dispersion derived from the total mass (1000±70M☉) and
half-mass radius (3.4±0.2pc). From the comparison to other clusters
and to numerical simulations, we conclude that NGC 2244 may be unbound
and that it possibly may have even formed in a super-virial state.
Description:
Two tables are provided. The first one contains the kinematic
parameters and photometry of all the sources in the field, along with
the individual membership probabilities obtained by the Probabilistic
Random Forest classifier. In the second table, we provide the
positions, spectral types, extinction and pseudo-equivalent-widths of
Halpha line for 251 objects with discernible existing optical spectra
taken with VIMOS/VLT.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 361 210362 Full catalogue
tablea1.dat 46 251 Stellar parameters derived from VIMOS spectra
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- --- [Gaia EDR3]
11- 29 I19 --- GaiaEDR3 Gaia EDR3 unique source identifier
31- 45 F15.11 deg RAdeg Right ascension (ICRS) at Ep=2016.0
47- 61 F15.11 deg DEdeg Declination (ICRS) at Ep=2016.0
63- 71 F9.4 mas/yr pmRA Proper motion in RA
73- 78 F6.4 mas/yr e_pmRA Proper motion uncertainty in RA
80- 88 F9.4 mas/yr pmDE Proper motion in Dec
90- 95 F6.4 mas/yr e_pmDE Proper motion uncertainty in Dec
97-105 F9.4 mas plx Parallax
107-112 F6.4 mas e_plx Parallax uncertainty
114-122 F9.6 mag RPmag ?=- RP mean magnitude (Gaia EDR3)
124-131 F8.6 mag e_RPmag ?=- RP mean magnitude error (Gaia EDR3)
133-141 F9.6 mag BPmag ?=- BP mean magnitude (Gaia EDR3)
143-150 F8.6 mag e_BPmag ?=- BP mean magnitude error (Gaia EDR3)
152-160 F9.6 mag Gmag ?=- G mean magnitude (Gaia EDR3)
162-169 F8.6 mag e_Gmag ?=- G mean magnitude error (Gaia EDR3)
171-179 F9.6 mag Halpha ?=- Halpha magnitude (Vega)
181-188 F8.6 mag e_Halpha ?=- Halpha magnitude error (Vega)
190-198 F9.6 mag gmag ?=- g magnitude in PS1 system (AB)
200-207 F8.6 mag e_gmag ?=- g magnitude error in PS1 system (AB)
209-217 F9.6 mag rmag ?=- r magnitude in PS1 system (AB)
219-226 F8.6 mag e_rmag ?=- r magnitude error in PS1 system (AB)
228-236 F9.6 mag imag ?=- i magnitude in PS1 system (AB)
238-245 F8.6 mag e_imag ?=- i magnitude error in PS1 system (AB)
247-255 F9.6 mag zmag ?=- z magnitude in PS1 system (AB)
257-264 F8.6 mag e_zmag ?=- z magnitude error in PS1 system (AB)
266-274 F9.6 mag ymag ?=- y magnitude in PS1 system (AB)
276-283 F8.6 mag e_ymag ?=- y magnitude error in PS1 system (AB)
285-293 F9.6 mag Jmag ?=- J magnitude 2MASS system (Vega)
295-302 F8.6 mag e_Jmag ?=- J magnitude error 2MASS system (Vega)
304-312 F9.6 mag Hmag ?=- H magnitude 2MASS system (Vega)
314-321 F8.6 mag e_Hmag ?=- H magnitude error 2MASS system (Vega)
323-331 F9.6 mag Ksmag ?=- Ks magnitude 2MASS system (Vega)
333-340 F8.6 mag e_Ksmag ?=- Ks magnitude error 2MASS system (Vega)
342-361 F20.18 --- Pmemb [0/1] Membership probability from
probabilistic random forest (run F1)
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension (J2000.0)
4- 5 I2 min RAm Right ascension (J2000.0)
7- 11 F5.2 s RAs Right ascension (J2000.0)
13- 14 I2 deg DEd Declination (J2000.0)
16- 17 I2 arcmin DEm Declination (J2000.0)
19- 22 F4.1 arcsec DEs Declination (J2000.0)
24- 28 A5 --- SpType Optical spectral type
30- 32 F3.1 mag Av Extinction
34- 40 F7.2 0.1nm EW Pseudo-equivalent width of Halpha line
(in Angstroems)
42- 46 F5.2 0.1nm e_EW Uncertainty of pseudo-equivalent width
of Halpha line (in Angstroems)
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Acknowledgements:
Koraljka Muzic, kmuzic(at)sim.ul.pt
(End) Patricia Vannier [CDS] 07-Oct-2022