J/A+A/654/A150 Gas and young stars in CMa OB1 assoc. (Gregorio-Hetem+, 2021)
Comparing the spatial and kinematic distribution of gas and young stars around
the shell-like structure in the CMa OB1 association.
Gregorio-Hetem J., Lefloch B., Hetem A., Montmerle T., Fernandes B.,
Mendoza E.F., De Simone M.
<Astron. Astrophys. 654, A150 (2021)>
=2021A&A...654A.150G 2021A&A...654A.150G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, pre-main sequence ; Interstellar medium ; Infrared sources
Keywords: stars: pre-main sequence - circumstellar matter -
ISM: individual objects: CMa OB1 - ISM: clouds -
ISM: kinematics and dynamics - infrared: stars
Abstract:
The relationship between young stellar clusters and their respective
parental molecular clouds remains an open issue. Recent inquiries
consider the similarities between substructures of clouds and clusters
and whether they are a coincidence or, rather, an indication of a
physical relationship. To address these issues, we studied the CMa
OB1/R1 region, which shows evidence of a complex star formation
history.
We obtained molecular cloud mapping with the IRAM-30 metre telescope
to reveal the physical conditions of an unexplored side of the CMa
region with the aim of comparing the morphology of the clouds to the
distribution of young stellar objects (YSOs). We also studied the
cloud kinematics in pursuit of gradients and jet signatures that could
trace different star formation scenarios.
The YSOs were selected on the basis of astrometric data from Gaia EDR3
that characterize the moving groups. The distance of 1099-24+25pc
was obtained for the sample, based on the mean error-weighted
parallax. Optical and near-infrared photometry was used to verify the
evolutionary status and circumstellar characteristics of the YSOs.
Among the selected candidates, we found 40 members associated with the
cloud: 1 Class I, 11 Class II, and 28 Class III objects. Comparing the
spatial distribution of the stellar population with the cores revealed
by the 13CO map, we verified that peaks of emission coincide with
the position of YSOs, confirming the association of these objects to
their dense natal gas.
Our observations support the large-scale scenario of the CMa
shell-like structure formation as a relic of successive supernova
events.
Description:
We used the IRAM-30m telescope (Sierra Nevada, Spain) to map the
emission of the ground-state rotational transition J=1-0 of CO and
its rare 13CO and C18O isotopologues in Cloud 12. Observations were
carried out during three observing runs in October 2018 (project
043-18), March 2019 (project 120-19), and October 2019 (project
034-20), using the EMIR receiver at 3mm in its 2SB mode connected to
the FTS spectrometer in its 192kHz resolution mode. Observations were
carried out using the "on-the-fly" mode. We chose a reference
position, which we checked to be free of emission in the CO J=1-0
line.
Objects:
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RA (2000) DE Designation(s)
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07 08 21.3 -11 04 50 CMa OB1/R1 = Ass CMa R1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 76 44 Membership probability, parallax, proper motion,
and Gaia EDR3 photometry
tablea2.dat 81 44 Infrared photometry for stellar populations
list.dat 112 3 List of fits datacubes
fits/* . 3 Individual datacubes
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See also:
J/MNRAS/310/210 : Stellar composition of CMa R1 (Shevchenko+, 1999)
J/A+A/506/711 : Canis Major R1 X-ray sources (Gregorio-Hetem+, 2009)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaEDR3 Gaia EDR3 source id
20 A1 --- n_GaiaEDR3 Note for stars identified as Hα
emitters (1)
22- 23 I2 % Pmemb Membership probability
25- 28 F4.2 mag plx Parallax
30- 33 F4.2 mag e_plx Parallax error
35- 39 F5.2 mas/yr pmRA Proper motion along RA, pmRA*cosDE
41- 44 F4.2 mas/yr e_pmRA Proper motion along RA error
46- 49 F4.2 mas/yr pmDE Proper motion along DE
51- 54 F4.2 mas/yr e_pmDE Proper motion along DE error
56- 60 F5.2 mag Gmag Gaia G magnitude
62- 66 F5.2 mag BPmag Gaia BP magnitude
68- 72 F5.2 mag RPmag Gaia RP magnitude
74- 76 A3 --- Class Classification (I, II or III)
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Note (1): Stars identified as Hα emitters as follows:
a = ID 381 (ESO-HA 381 in Simbad, Pettersson & Reipurth, 2019A&A...630A..90P 2019A&A...630A..90P)
b = ID 387 (ESO-HA 387 in Simbad, Pettersson & Reipurth, 2019A&A...630A..90P 2019A&A...630A..90P)
c = ID 390 (ESO-HA 390 in Simbad, Pettersson & Reipurth, 2019A&A...630A..90P 2019A&A...630A..90P)
d = ID 392 (ESO-HA 392 in Simbad, Pettersson & Reipurth, 2019A&A...630A..90P 2019A&A...630A..90P)
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Byte-by-byte Description of file: tablea2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 source id
21- 36 A16 --- 2MASS 2MASS name (HHMMSSss+DDMMSSs)
38- 42 F5.2 mag Jmag 2MASS J magnitude
44- 48 F5.2 mag Hmag 2MASS H magnitude
50- 54 F5.2 mag Kmag 2MASS K magnitude
56- 60 F5.2 mag W1mag WISE W1 magnitude
62- 66 F5.2 mag W2mag WISE W2 magnitude
68- 72 F5.2 mag W3mag WISE W3 magnitude
74- 77 F4.2 mag W4mag WISE W4 magnitude
79- 81 A3 --- Class Classification (I, II or III)
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 30 I3 --- Nz Number of slices
32- 38 I7 m/s bVrad Lower value of radial velocity interval
40- 45 I6 m/s BVrad Upper value of radial velocity interval
47- 49 I3 m/s dVrad Radial velocity resolution
51- 60 F10.3 MHz Freq Reference frequency
62- 66 I5 Kibyte size Size of FITS file
68- 77 A10 --- FileName Name of FITS file, in subdirectory fits
79-112 A34 --- Title Title of the FITS file
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Acknowledgements:
Jane Gregorio-Hetem, gregorio-hetem(at)usp.br
Annibal Hetem, annibal.hetem(at)gmail.com
(End) Jane Gregorio-Hetem [USP], Patricia Vannier [CDS] 18-Oct-2021