J/A+A/630/A90 Halpha emission-line stars in Canis Major (Pettersson+, 2019)
H-alpha emission-line stars in molecular clouds. III. Canis Major.
Pettersson B., Reipurth B.
<Astron. Astrophys. 630, A90 (2019)>
=2019A&A...630A..90P 2019A&A...630A..90P (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Stars, emission ; Stars, pre-main sequence ;
Photometry
Keywords: stars: emission-line, Be - stars: pre-main sequence - stars: formation
Abstract:
A deep objective-prism survey for H-alpha emission stars towards the
Canis Major star-forming clouds was performed. A total of 398 Halpha
emitters were detected, 353 of which are new detections. There is a
strong concentration of these H-alpha emitters towards the molecular
clouds surrounding the CMa OB1 association, and it is likely that
these stars are young stellar objects recently born in the clouds. An
additional population of H-alpha emitters is scattered all across the
region, and probably includes unrelated foreground dMe stars and
background Be stars. About 90% of the H-alpha emitters are detected by
WISE, of which 75% was detected with usable photometry. When plotted
in a WISE colour-colour diagram it appears that the majority are Class
II YSOs. Coordinates and finding charts are provided for all the new
stars, and coordinates for all the detections. We searched the
Gaia-DR2 catalogue and from 334 Halpha emission stars with useful
parallaxes, we selected a subset of 98 stars that have parallax errors
of less than 20% and nominal distances in the interval 1050 to 1350pc
that surrounds a strong peak at 1185pc in the distance distribution.
Similarly, Gaia distances were obtained for 51 OB-stars located
towards Canis Major and selected with the same parallax errors as the
H-alpha stars. We find a median distance for the OB stars of 1182pc,
in excellent correspondence with the distance from the H-alpha stars.
Two known runaway stars are confirmed as members of the association.
Finally, two new Herbig-Haro objects are identified.
Description:
We present H-alpha strength estimates for 398 emission-line stars in
the Canis Major OB1 region. Positions and JHKs-photometry were
extracted from 2MASS All-Sky Catalog, G-band photometry and distances
from Gaia-DR2 and distances from Gaia-DR2. Uncertain values in one or
more photometric bands are marked with a ':'.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 138 398 H-alpha emission-line stars in CMa OB1
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/328 : AllWISE Data Release (Cutri+ 2013)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/127/1117 : Halpha emission-line stars in NGC2264 (Reipurth+, 2004)
J/A+A/570/A30 : Hα emission-line stars in M42 (Pettersson+, 2014)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ESO-Ha ? ESO H-alpha number (1)
6- 12 A7 --- Other Other names (2)
14 I1 h RAh Right Ascension (J2000) (3)
16- 17 I2 min RAm Right Ascension (J2000) (3)
19- 23 F5.2 s RAs Right Ascension (J2000) (3)
25 A1 --- DE- Declination sign (J2000) (3)
26- 27 I2 deg DEd Declination (J2000) (3)
29- 30 I2 arcmin DEm Declination (J2000) (3)
32- 35 F4.1 arcsec DEs Declination (J2000) (3)
37- 39 A3 --- Ha H-alpha emission-line strength (4)
41- 45 F5.2 mag Gmag Gaia DR2 (Cat. I/345) G-band
47- 51 F5.2 mag Jmag ? 2MASS (Cat. II/246) J magnitude
52 A1 --- u_Jmag Uncertainty flag for Jmag
54- 58 F5.2 mag Hmag ? 2MASS (Cat. II/246) H magnitude
59 A1 --- u_Hmag Uncertainty flag for Hmag
61- 65 F5.2 mag Ksmag ? 2MASS (Cat. II/246) Ks magnitude
66 A1 --- u_Ksmag Uncertainty flag for Ksmag
68- 72 F5.2 mag [3.4] ? AllWISE (Cat. II/328) WISE 3.4um-band
73 A1 --- u_[3.4] Uncertainty flag for [3.4]
75- 79 F5.2 mag [4.6] ? AllWISE (Cat. II/328) WISE 4.6um-band
80 A1 --- u_[4.6] Uncertainty flag for [4.6]
82- 86 F5.2 mag [12] ? AllWISE (Cat. II/328) WISE 12um-band
87 A1 --- u_[12] Uncertainty flag for [12]
89- 92 I4 pc Dist ? Distance, from Gaia DR2 parallaxes
94- 98 I5 pc E_Dist ? Error on dist (upper value)
101-104 I4 pc e_Dist ? Error on dist (lower value)
106-138 A33 --- Notes Notes to individual objects
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Note (1): The numbers fall into two groups (1835-2123 and 2706-2769),
will be ESO-HA NNNN im Simbad.
Note (2): Other names origin:
Kiso = Wiramihardja et al. (1986PASJ...38..395W 1986PASJ...38..395W)
SS = Stephenson and Sanduleak (1977ApJS...33..459S 1977ApJS...33..459S, Cat. III/180)
LkHa = Herbig (1960ApJS....4..337H 1960ApJS....4..337H), Em* LkHA NNN in Simbad
OSP = Ogura et al. (2002AJ....123.2597O 2002AJ....123.2597O, Cat. J/AJ/123/2597),
[OSP2002] BRC 27 NN in Simbad
Note (3): Positions extracted from the 2MASS All-Sky Catalog, Cat. II/246.
Note (4): The H-alpha strength is defined so 1 is weak emission against a strong
continuum and 5 is strong emission against a weak or invisible continuum.
Hyphenated values may represent either variability and/or uncertainty in
the estimate.
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Acknowledgements:
Bertil Pettersson, Bertil.Pettersson(at)physics.uu.se
References:
Reipurth et al., Paper I 2004AJ....127.1117R 2004AJ....127.1117R, Cat. J/AJ/127/1117
Pettersson et al., Paper II 2014A&A...570A..30P 2014A&A...570A..30P, Cat. J/A+A/570/A30
(End) Patricia Vannier [CDS] 28-Aug-2019