J/ApJ/859/73 Variability of RSGs in M31 from the iPTF survey (Soraisam+, 2018)
Variability of red supergiants in M31 from the Palomar Transient Factory.
Soraisam M.D., Bildsten L., Drout M.R., Bauer E.B., Gilfanov M., Kupfer T.,
Laher R.R., Masci F., Prince T.A., Kulkarni S.R., Matheson T., Saha A.
<Astrophys. J., 859, 73 (2018)>
=2018ApJ...859...73S 2018ApJ...859...73S
ADC_Keywords: Stars, giant; Photometry, RI; Stars, variable;
Magnitudes, absolute; Effective temperatures; Surveys
Keywords: galaxies: groups: individual (M31); stars: massive;
stars: oscillations; supergiants; surveys
Abstract:
Most massive stars end their lives as red supergiants (RSGs), a
short-lived evolutionary phase when they are known to pulsate with
varying amplitudes. The RSG period-luminosity (PL) relation has been
measured in the Milky Way, the Magellanic Clouds and M33 for about 120
stars in total. Using over 1500 epochs of R-band monitoring from the
Palomar Transient Factory survey over a five-year period, we study the
variability of 255 spectroscopically cataloged RSGs in M31. We find
that all RGSs brighter than MK~-10mag (log(L/L☉)>4.8) are
variable at ΔmR>0.05mag. Our period analysis finds 63 with
significant pulsation periods. Using the periods found and the known
values of MK for these stars, we derive the RSG PL relation in M31
and show that it is consistent with those derived earlier in other
galaxies of different metallicities. We also detect, for the first
time, a sequence of likely first-overtone pulsations. Comparison to
stellar evolution models from MESA confirms the first-overtone
hypothesis and indicates that the variable stars in this sample have
12M☉<M<24M☉. As these RSGs are the immediate progenitors
to Type II-P core-collapse supernovae (SNe), we also explore the
implication of their variability in the initial-mass estimates for SN
progenitors based on archival images of the progenitors. We find that
this effect is small compared to the present measurement errors.
Description:
The iPTF survey, carried out with the 1.2m Samuel Oschin telescope at
Palomar Observatory, continued imaging M31 (including the outskirts of
this galaxy) from its predecessor, the PTF survey, with the same
wide-field detector covering more than 7deg2 with 11 active CCDs,
and a typical spatial sampling of 2" full-width at half maximum
(FWHM). The baseline of the data for M31 analyzed here extends from
2012 May until 2017 February. The imaging was done in two passbands, R
and g, with the largest fraction (>80%) in R at a limiting magnitude
reaching ∼21mag and an average cadence of 1 day (typically taking 2
observations per night). We thus use only the R-band PTF/iPTF
data set of about 10000 images.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 58 244 Properties of the red supergiants (RSGs) in M31
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
J/AJ/96/1884 : BVRJHK photometry of M31 red supergiants (Humphreys+ 1988)
J/ApJ/501/153 : VRB photometry of red supergiants (Massey 1998)
J/A+A/445/423 : WeCAPP Survey. M31 variables (Fliri+, 2006)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/ApJ/727/53 : Red supergiant stars in the LMC. I. (Yang+, 2011)
J/A+A/537/A146 : Stellar models with rotation. 0.8<M<120. (Ekstrom+, 2012)
J/ApJ/745/156 : M31 Cepheids with HST/WFC3 (Riess+, 2012)
J/ApJ/754/35 : Red supergiant stars in the SMC. II. (Yang+, 2012)
J/A+A/558/A131 : Model spectra of hot stars at the pre-SN stage (Groh+, 2013)
J/A+A/560/A16 : Comparison of evolutionary tracks (Martins+, 2013)
J/ApJ/826/224 : RSG and foreground candidates in M31 (Massey+, 2016)
J/ApJ/825/50 : Variable stars in M31+M33. III. YSGs + RSGs (Gordon+, 2016)
J/AJ/154/231 : Multi-epoch multi-band photometry of B1-392 (Saha+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/255] ID of the star
5- 23 A19 --- ID JHHMMSS.ss+DDMMSS.s identifier (1)
25- 30 F6.2 mag KMag [-12.6/-8.4]? The absolute K-band magnitude (1)
32- 35 I4 K Teff [3625/4300]? Effective Temperature (1)
38- 41 F4.2 --- log(L) [4.2/5.9]? log of bolometric luminosity
of the star (1)
43- 47 F5.2 mag Rmag [15.4/19.7] R-band mean magnitude of the lightcurve
50- 53 F4.2 mag RMS [0.01/0.7]?=0 RMS value of lightcurve (2)
56- 58 I3 d Per [77/893]? Period
--------------------------------------------------------------------------------
Note (1): These values are obtained from Massey & Evans (2016, J/ApJ/826/224)
Note (2): RSGs, whose variability is below our threshold (see Fig.2 and 3) have
an RMS=0.00
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Soraisam et al. Paper II. 2020ApJ...893...11S 2020ApJ...893...11S Cat. J/ApJ/893/11
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-May-2019