J/ApJ/910/80 Photometry and astrometry of M36 members (Panja+, 2021)
Sustaining star formation in the Galactic star cluster M36?
Panja A., Chen W.P., Dutta S., Sun Y., Gao Y., Mondal S.
<Astrophys. J., 910, 80 (2021)>
=2021ApJ...910...80P 2021ApJ...910...80P
ADC_Keywords: Clusters, open; Photometry, infrared; Spectra, optical;
Radial velocities; Proper motions; Stars, distances
Keywords: Open star clusters ; Stellar kinematics ; Stellar dynamics ;
Pre-main sequence stars ; Extinction ; Molecular clouds
Abstract:
We present comprehensive characterization of the Galactic open cluster
M36. Some 200 member candidates, with an estimated contamination rate
of ∼8%, have been identified on the basis of proper motion and
parallax measured by the Gaia DR2. The cluster has a proper motion
grouping around (µαcosδ=-0.15±0.01mas/yr, and
µδ=-3.35±0.02mas/yr), distinctly separated from the field
population. Most member candidates have parallax values 0.7-0.9mas,
with a median value of 0.82±0.07mas (distance ∼1.20±0.13kpc). The
angular diameter of 27'±0.4' determined from the radial density
profile then corresponds to a linear extent of 9.42±0.14pc. With an
estimated age of ∼15Myr, M36 is free of nebulosity. To the southwest
of the cluster, we discover a highly obscured (AV up to ∼23mag),
compact (∼1.9'x1.2') dense cloud, within which three young stellar
objects in their infancy (ages ≲0.2Myr) are identified. The molecular
gas, 3.6pc in extent, contains a total mass of (2-3)x102M☉,
and has a uniform velocity continuity across the cloud, with a
velocity range of -20 to -22km/s, consistent with the radial
velocities of known star members. In addition, the cloud has a derived
kinematic distance marginally in agreement with that of the star
cluster. If physical association between M36 and the young stellar
population can be unambiguously established, this manifests a
convincing example of prolonged star formation activity spanning up to
tens of Myr in molecular clouds.
Description:
This study has made use of a variety of data.
The Gaia Data Release 2 (Gaia DR2; see I/345) furnishes precise
astrometry and photometry of three broadband magnitudes in
G (330-1050nm), GBP (330-680nm), and GRP (630-1050nm).
The near-infrared J-, H-, and K-band photometric data were obtained
from the UKIRT Infrared Deep Sky Survey (UKIDSS) DR10PLUS Galactic
Plane Survey (GPS; see II/319) and the Two Micron All Sky Survey
(2MASS) Point Source Catalog (PSC, II/246). The mid-infrared
photometric data for point sources toward the M 36 cluster was
obtained from the Spitzer Warm Mission (Hora+ 2012SPIE.8442E..39H 2012SPIE.8442E..39H)
survey.
See Section 2.2.
After a 5yr Large Sky Area Multi-Object Fiber Spectroscopic Telescope
(LAMOST) regular survey conducted between 2012 and 2017, more than
eight million spectra were obtained, with a spectral resolution of
R∼1800 over the wavelength range of 370-900nm. The stellar parameters
are collected from LAMOST DR5 (see V/164) for this work.
The CO observations toward M 36 were conducted on 2014 March 2 using
the 13.7m millimeter-wavelength telescope of the Purple Mountain
Observatory in Delingha, China, as a part of the Milky Way Imaging
Scroll Painting project dedicated to map the molecular gas along the
northern Galactic plane (MWISP; Su+ 2019ApJS..240....9S 2019ApJS..240....9S). The
molecular lines of 12CO (J=1-0) in the upper sideband, and 13CO
(J=1-0) together with C18O (J=1-0) in the lower sideband were
observed simultaneously. See Section 2.4.
Objects:
----------------------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------------------
05 36 20 +34 08.1 M 36 = NGC 1960
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 211 200 Photometry and astrometry of members
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/297 : NOMAD Catalog (Zacharias+ 2005)
II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
II/368 : The Spitzer (SEIP) source list (SSTSL2) (Spitzer Science Center, 2021)
J/A+A/352/228 : Transitional YSOs candidates (Magnier+, 1999)
J/A+A/357/471 : BV and proper motions in NGC 1960 & NGC 2194 (Sanner+, 2000)
J/AZh/80/8 : Proper motions of open star clusters (Loktin+, 2003)
J/AJ/126/1916 : JHK photometry of young clusters near the Sun (Porras+, 2003)
J/AJ/132/1669 : Wide-field CCD phot. around nine open clusters (Sharma+, 2006)
J/A+A/468/151 : Nearby open clusters radii and masses (Piskunov+, 2007)
J/AJ/134/2340 : Membership of Praesepe & Coma Berenices (Kraus+, 2007)
J/AJ/136/118 : Open clusters as galactic disk tracers. I. (Frinchaboy+, 2008)
J/ApJS/179/249 : Low-luminosity embedded protostar population (Dunham+, 2008)
J/ApJ/688/1142 : Star formation in W5: Spitzer observations (Koenig+, 2008)
J/A+A/495/807 : Shape parameters for 650 open clusters (Kharchenko+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/MNRAS/399/2146 : Orbits of open clusters in the Galaxy (Wu+, 2009)
J/ApJ/770/1 : YSO candidates in G38.9-0.4 region (Alexander+, 2013)
J/MNRAS/434/806 : Pre-main-sequence isochrones. II. SFR (Bell+, 2013)
J/MNRAS/434/2438 : NGC 1960 (RI)c photometric catalogue (Jeffries+, 2013)
J/A+A/575/A120 : DANCe study of M35 (NGC 2168) (Bouy+, 2015)
J/MNRAS/454/3597 : NGC 2282 BVI Ha observations (Dutta+, 2015)
J/ApJ/831/116 : Phot. and spectroscopy of PMS stars in NGC 2264 (Lim+, 2016)
J/ApJ/864/154 : Planck cold clump G108.37-01.06 YSO candidates (Dutta+, 2018)
J/A+A/619/A180 : Gaia DR2 phot. sensitivity curves (Maiz Apellaniz+, 2018)
J/ApJ/885/131 : ∼200 high-mass SFR plx & proper motion with VLBI (Reid+, 2019)
J/AJ/159/153 : Optical and IR photR. in the HII region Sh2-242 (Panja+, 2020)
J/AJ/161/160 : BINOCS: NEWFIRM & IRAC IR phot. of clusters (Thompson+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- Seq [1/200] Running sequence number
6- 14 F9.6 deg RAdeg [83.85/84.32] Right Ascension (J2000)
16- 24 F9.6 deg DEdeg [33.92/34.33] Declination (J2000)
26- 32 F7.3 mag Jmag [8.8/16.3]?=999 Apparent J band magnitude
34- 40 F7.3 mag e_Jmag [0.001/0.05]?=999 Uncertainty in Jmag
42- 47 F6.3 mag Hmag [8.69/15.55] Apparent H band magnitude
49- 55 F7.3 mag e_Hmag [0/0.05]?=999 Uncertainty in Hmag
57- 62 F6.3 mag Kmag [8.5/15.28] Apparent K band magnitude
64- 70 F7.3 mag e_Kmag [0/0.05]?=999 Uncertainty in Kmag
72- 78 F7.3 mag 3.6mag [8/15.1]?=999 Spitzer/IRAC 3.6um band
apparent magnitude
80- 86 F7.3 mag e_3.6mag [0.02/0.1]?=999 Uncertainty in 3.6mag
88- 94 F7.3 mag 4.5mag [7.7/15]?=999 Spitzer/IRAC 4.5um band
apparent magnitude
96- 102 F7.3 mag e_4.5mag [0.02/0.07]?=999 Uncertainty in 4.5mag
104- 109 F6.3 mag Gmag [9/19.42] Gaia DR2 broad G band mean magnitude
111- 115 F5.3 mag e_Gmag [0/0.007] Uncertainty in Gmag
117- 122 F6.3 mag BPmag [9/21.13] Gaia DR2 Blue band integrated mean
magnitude
124- 128 F5.3 mag e_BPmag [0.001/0.2] Uncertainty in BPmag
130- 135 F6.3 mag RPmag [9/18.11] Gaia DR2 Red band integrated mean
magnitude
137- 141 F5.3 mag e_RPmag [0.001/0.04] Uncertainty in RPmag
143- 148 F6.3 mas/yr pmRA [-0.62/0.31] Proper motion in RA * cos (DE)
150- 154 F5.3 mas/yr e_pmRA [0.04/1.02] Uncertainty in pmRA
156- 161 F6.3 mas/yr pmDE [-3.8/-2.99] Proper motion in DE
163- 167 F5.3 mas/yr e_pmDE [0.03/0.8] Uncertainty in pmDE
169- 174 F6.4 mas plx [0.7/0.9] Absolute stellar parallax
176- 181 F6.4 mas e_plx [0.02/0.5] Uncertainty in plx
183- 187 F5.3 kpc Dist [1/1.73] Estimated Gaia DR2 distance
189- 192 F4.2 kpc e_Dist [0.03/0.8] Lower uncertainty in Dist
194- 197 F4.2 kpc E_Dist [0.03/2.1] Upper uncertainty in Dist
199- 204 F6.2 km/s RVel [-20/-5]?=999 LAMOST DR5 radial velocity
206- 211 F6.2 km/s e_RVel [5/13]?=999 Uncertainty in RVel
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Aug-2022