J/MNRAS/475/2003 Red supergiant population in Perseus arm (Dorda+, 2018)
The red supergiant population in the Perseus arm.
Dorda R., Negueruela I., Gonzalez-Fernandez C.
<Mon. Not. R. Astron. Soc. 475, 2003 (2018)>
=2018MNRAS.475.2003D 2018MNRAS.475.2003D (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Stars, supergiant ; Stars, luminous ;
MK spectral classification
Keywords: stars: late-type - stars: massive - supergiants -
open clusters and associations: general - Galaxy: stellar content
Abstract:
We present a new catalogue of cool supergiants in a section of the
Perseus arm, most of which had not been previously identified. To
generate it, we have used a set of well-defined photometric criteria
to select a large number of candidates (637) that were later observed
at intermediate resolution in the infrared calcium triplet spectral
range, using a long-slit spectrograph. To separate red supergiants
from luminous red giants, we used a statistical method, developed in
previous works and improved in the present paper. We present a method
to assign probabilities of being a red supergiant to a given spectrum
and use the properties of a population to generate clean samples,
without contamination from lower luminosity stars. We compare our
identification with a classification done using classical criteria and
discuss their respective efficiencies and contaminations as
identification methods. We confirm that our method is as efficient at
finding supergiants as the best classical methods, but with a far
lower contamination by red giants than any other method. The result is
a catalogue with 197 cool supergiants, 191 of which did not appear in
previous lists of red supergiants. This is the largest coherent
catalogue of cool supergiants in the Galaxy.
Description:
The targets were observed during two different campaigns. The first
one was done in 2011, on the nights of October 16-18. The second
campaign was carried out in 2012, from September 3rd to 7th. We used
the Intermediate Dispersion Spectrograph, mounted on the 2.5 m Isaac
Newton Telescope (INT) in La Palma (Spain).
In total, we observed 637 unique targets, 102 in 2011 and 535 in 2012,
without any overlap between epochs. As discussed above, 43 of them are
CSGs with well-determined SpTs (all but one observed in the 2012 run)
that were included in the calibration sample of Paper III (see
appendix B in that work). These objects are not considered part of the
Perseus sample studied here. This leaves 594 targets in our sample,
which are detailed in perseus.dat file.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
perseus.dat 65 594 Catalogue of targets observed in the Perseus arm
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See also:
J/A+A/578/A3 : New survey of supergiants in the MCs (Gonzalez-Fernandez+, 2015)
Byte-by-byte Description of file: perseus.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- ID Designation (PERNNN)
8- 9 I2 h RAh Right Ascension (Eq=J2000, Ep= 1989.0)
11- 12 I2 min RAm Right Ascension (Eq=J2000, Ep= 1989.0)
14- 18 F5.2 s RAs Right Ascension (Eq=J2000, Ep= 1989.0)
20 A1 --- DE- Declination sign (Eq=J2000, Ep= 1989.0)
21- 22 I2 deg DEd Declination (Eq=J2000, Ep= 1989.0)
24- 25 I2 arcmin DEm Declination (Eq=J2000, Ep= 1989.0)
27- 30 F4.1 arcsec DEs Declination (Eq=J2000, Ep= 1989.0)
32- 35 I4 yr Ep.Obs Epoch in which it was observed
37- 40 A4 --- SpType Spectral type assigned
42- 47 A6 --- LC Luminosity class assigned
49- 53 F5.3 --- P(PCA) ? Probability of being a CSG calculated
through the PCA method
55- 59 F5.3 --- P(CaT) ? Probability of being a CSG calculated
through the CaT criterion
61- 65 F5.3 --- P(Ti/Fe) ? Probability of being a CSG calculated
through the ratio of Ti-to-Fe criterion
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Acknowledgements:
Ricardo Dorda, ricardo.dorda(at)ua.es
References:
Gonzalez-Fernandez et al., Paper I 2015A&A...578A...3G 2015A&A...578A...3G, Cat. J/A+A/578/A3
Dorda et al., Paper II 2016A&A...592A..16D 2016A&A...592A..16D
Dorda et al., Paper III 2016A&A...595A.105D 2016A&A...595A.105D
(End) Ricardo Dorda [Univ. Alicante], Patricia Vannier [CDS] 29-Mar-2018