J/MNRAS/487/4832 Period-luminosity relation of red supergiants (Chatys+, 2019)
The period-luminosity relation of red supergiants with Gaia DR2.
Chatys F.W., Bedding T.R., Murphy S.J., Kiss L.L., Dobie D., Grindlay J.E.
<Mon. Not. R. Astron. Soc., 487, 4832-4846 (2019)>
=2019MNRAS.487.4832C 2019MNRAS.487.4832C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, late-type ; Stars, supergiant ; Infrared
Keywords: stars: evolution - stars: late-type - supergiants -
solar neighbourhood
Abstract:
We revisit the K-band period-luminosity (P-L) relations of Galactic
red supergiants using Gaia Data Release 2 parallaxes and up to 70yr of
photometry from AAVSO and ASAS campaigns. In addition, we examine 206
LMC red supergiants using 50yr of photometric data from the digitized
Harvard Astronomical Plate Collection. We identified periods by
computing power spectra and calculated the period-luminosity relations
of our samples and compared them with the literature. Newly available
data tighten the P-L relations substantially. Identified periods form
two groups: one with periods of 300-1000d, corresponding to
pulsations, and another with Long Secondary Periods between 1000 and
8000d. Among the 48 Galactic objects we find shorter periods in 25
stars and long secondary periods in 23 stars. In the LMC sample we
identify 85 and 94 red supergiants with shorter and long secondary
periods, respectively. The P-L relation of the Galactic red
supergiants is in agreement with the red supergiants in both, the
Large Magellanic Cloud and the Andromeda galaxy. We find no clear
continuity between the known red giant period-luminosity sequences,
and the red supergiant sequences investigated here.
Description:
Using long-term light curves from several campaigns we analysed over
220 RSGs in the LMC and the Milky Way and studied their main
pulsational characteristics.
We obtained our list of 206 supergiants primarily from Yang & Jiang
(2011ApJ...727...53Y 2011ApJ...727...53Y, Cat. J/ApJ/727/53, 190 objects), with the other
objects taken from Massey & Olsen (2003AJ....126.2867M 2003AJ....126.2867M, Cat.
J/AJ/126/2867, No. 205, 208, 209, 210, 216, and 217), Boyer et al.
(2011AJ....142..103B 2011AJ....142..103B, Cat. J/AJ/142/103, No. 191, 195, 196, 199, and
200), Catchpole & Feast (1981MNRAS.197..385C 1981MNRAS.197..385C, No. 227), Kastner et al.
(2008AJ....136.1221K 2008AJ....136.1221K, Cat. J/AJ/136/1221, No. 219, 220, and 225), and
Levesque et al. (2006ApJ...645.1102L 2006ApJ...645.1102L, No. 223). We queried the DASCH
online data base (http://dasch.rc.fas.harvard.edu/) with a search
radius of 5arcsec and determined the correct star by looking at the
magnitude and position. We extracted time and brightness data and we
trimmed each light curve so it only contained measurements on the
interval 2420000-2440000(JD), where the majority of useful
observations occurred.
We used the Lomb-Scargle periodogram (Lomb 1976Ap&SS..39..447L 1976Ap&SS..39..447L;
Scargle 1982ApJ...263..835S 1982ApJ...263..835S) to calculate the power spectra and
identify periods. We searched for frequencies between 0.000125 and
0.01d-1, corresponding to periods of 100-8000d.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 67 167 Coordinates, K-band magnitude, period, and
amplitude of our sample of RSGs in the LMC
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/227] Source identifier
5- 11 F7.4 deg RAdeg Right ascension (J2000)
13- 20 F8.4 deg DEdeg Declination (J2000)
22- 25 I4 d P1 ? First period identified
27- 30 F4.2 mag amp1 ? Amplitude associated to P1
32- 35 I4 d P2 ? Second period identified
37- 40 F4.2 mag amp2 ? Amplitude associated to P2
42- 45 I4 d P3 ? Third period identified
47- 50 F4.2 mag amp3 ? Amplitude associated to P3
52- 55 F4.2 mag Kmag K-band magnitude from 2MASS (Cutri et al.
2003tmc..book.....C 2003tmc..book.....C, Cat. II/246)
57- 60 F4.2 mag e_Kmag Error on Kmag
62- 67 F6.2 mag KMAG Absolute K-band magnitude (1)
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Note (1): We adopted a distance modulus of µ(LMC)=18.476mag
(Pietrzynski et al. 2019Natur.567..200P 2019Natur.567..200P)
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 21-Nov-2022