J/MNRAS/469/4175 Be star candidates in Magellanic Clouds (Vieira+, 2017)
Proper motion separation of Be star candidates in the Magellanic Clouds and
the Milky Way.
Vieira K., Garcia-Varela A., Sabogal B.
<Mon. Not. R. Astron. Soc., 469, 4175-4182 (2017)>
=2017MNRAS.469.4175V 2017MNRAS.469.4175V (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Stars, Be ; Proper motions ; Radial velocities
Keywords: proper motions - stars: emission-line, Be - Magellanic Clouds
Abstract:
We present a proper motion investigation of a sample of Be star
candidates towards the Magellanic Clouds, which has resulted in the
identification of separate populations, in the Galactic foreground and
in the Magellanic background. Be stars are broadly speaking B-type
stars that have shown emission lines in their spectra. In this work,
we studied a sample of 2446 and 1019 Be star candidates towards the
Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC),
respectively, taken from the literature and proposed as possible Be
stars due to their variability behaviour in the OGLE-II I band. JHKs
magnitudes from the InfraRed Survey Facility catalogue and proper
motions from the Southern Proper Motion 4 catalogue were obtained for
1188 and 619 LMC and SMC Be stars candidates, respectively.
Colour-colour and vector-point diagrams were used to identify
different populations amongst the Be star candidates. In the LMC
sample, two populations with distinctive infrared colours and
kinematics were found, the bluer sample is consistent with being in
the LMC and the redder one with belonging to the Milky Way disc. This
settles the nature of the redder sample that had been described in
previous publications as a possible unknown subclass of stars amongst
the Be candidates in the LMC. In the SMC sample, a similar but less
evident result was obtained, since this apparent unknown subclass was
not seen in this galaxy. We confirm that in the selection of Be stars
by their variability, although generally successful, there is a higher
risk of contamination by Milky Way objects towards redder B-V and V-I
colours.
Description:
Be star candidates for the LMC and SMC were obtained from Sabogal et
al. (2005, Cat. J/MNRAS/361/1055) and Mennickent et al. (2002, Cat.
J/A+A/393/887), respectively. A total of 2446 and 1019 candidates were
listed, but we found four and two repeated entries in each catalogue.
In the LMC, the four sources that appeared twice each, had the same
sky coordinates, and very similar magnitudes and colours, only
differing in their type. In each case, one entry was a Type-4, and for
the lack of better information, we kept that entry in the catalogue
and deleted the other. In the SMC, a similar situation was faced and
since in the two cases one entry was a Type-1 star, this one was
selected in each case. The final lists of unique entries of Be star
candidates to match contained 2442 and 1017 stars in the LMC and SMC,
respectively.
JHKs magnitudes from the InfraRed Survey Facility catalogue and proper
motions from the Southern Proper Motion 4 catalogue were obtained for
1188 and 619 LMC and SMC Be stars candidates, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lmc-pm.dat 131 1188 Be stars candidates in the LMC, that includes
OGLE-II BVI and IRSF JHKs photometry and
SPM4 proper motions for each star (table A1)
lmc-rv.dat 72 8 Be stars candidates in the LMC that have full
kinematic information (table A2)
smc-pm.dat 131 619 Be stars candidates in the SMC, that includes
OGLE-II BVI and IRSF JHKs photometry and
SPM4 proper motions for each star (table A1)
smc-rv.dat 72 33 Be stars candidates in the SMC that have full
kinematic information (table A3)
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See also:
I/320 : SPM 4.0 Catalog (Girard+, 2011)
J/AcA/48/147 : OGLE SMC BVI photometry (Udalski+, 1998)
J/AcA/50/307 : OGLE LMC BVI photometry (Udalski+, 2000)
J/A+A/393/887 : SMC Be stars candidates (Mennickent+, 2002)
J/MNRAS/361/1055 : BVI photometry of LMC Be stars (Sabogal+, 2005)
J/MNRAS/421/3622 : Candidate Be stars in the Magellanic Clouds (Paul+, 2012)
Byte-by-byte Description of file: lmc-pm.dat smc-pm.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name OGLEIIID name (HHMMSS.ss+DDMMSS.s)
20- 25 F6.3 mag Vmag OGLE V magnitude
27- 32 F6.3 mag B-V OGLE B-V colour index
34- 39 F6.3 mag V-I OGLE V-I colour index
41- 43 A3 --- Type Type (1)
45- 53 I9 --- SPM4 SPM4 identification number
55- 64 F10.7 deg RAdeg Right ascension (J2000)
66- 76 F11.7 deg DEdeg Declination (J2000)
78- 85 F8.2 mas/yr pmRA SPM4 Proper motion along RA, pmRA*cosDE
86- 92 F7.2 mas/yr pmDE SPM4 Proper motion along DE
94- 98 F5.2 mas/yr e_pmRA rms uncertainty on pmRA
100-104 F5.2 mas/yr e_pmDE rms uncertainty on pmDE
106 I1 --- m [1/6] SPM4 Number of 1st-epoch plates used
108 I1 --- n [0/4] SPM4 Number of 2nd-epoch plates used
110 I1 --- i [0/9] SPM4 Number of 2nd-epoch CCD
frames used
112-117 F6.3 mag Jmag IRSF J magnitude
119-124 F6.3 mag Hmag IRSF H magnitude
126-131 F6.3 mag Kmag IRSF K magnitude
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Note (1): Types from Mennickent et al. (2002, Cat. J/A+A/393/887) as follows:
1 = objects showing outbursts
2 = objects showing high and low states
3 = objects showing periodic or near-periodic long-term oscillations
4 = objects showing light curves similar to those observed for
Galactic Be stars
1/2 = transition stars between Type-1 and Type-2 stars
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Byte-by-byte Description of file: lmc-rv.dat smc-rv.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- Name OGLEIIID name (HHMMSS.ss+DDMMSS.s)
20- 24 A5 --- SpType Spectral type
26- 28 I3 km/s RV Radial velocity
30- 31 I2 km/s e_RV rms uncertainty on RV
33- 38 F6.3 mag V-I OGLE V-I colour index
40- 48 I9 --- SPM4 SPM4 identification number
50- 55 F6.2 mas/yr pmRA Proper motion along RA, pmRA*cosDE
57- 62 F6.2 mas/yr pmDE Proper motion along DE
64- 67 F4.2 mas/yr e_pmRA rms uncertainty on pmRA
69- 72 F4.2 mas/yr e_pmDE rms uncertainty on pmDE
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 17-Apr-2020